diff --git a/3rdLibs b/3rdLibs new file mode 100644 index 0000000..c27a5df --- /dev/null +++ b/3rdLibs @@ -0,0 +1,8 @@ +o MDB: http://highlandsun.com/hyc/mdb/ + source : from OpenLDAP git repository + commit : 7333b6bdc90c49c332d4728c62c7904e64c95077 + license: OpenLDAP Public License + +o UTHash: http://uthash.sourceforge.net/ + version: 1.9.6 + license: BSD revised diff --git a/ChangeLog b/ChangeLog new file mode 100644 index 0000000..b09392f --- /dev/null +++ b/ChangeLog @@ -0,0 +1,3 @@ +o Sep 29th, 2012 + initial release + diff --git a/LICENSE b/LICENSE new file mode 100644 index 0000000..9060db6 --- /dev/null +++ b/LICENSE @@ -0,0 +1,49 @@ +------------------------------------------------------------------------- +The OpenLDAP Public License + Version 2.8, 17 August 2003 + +Redistribution and use of this software and associated documentation +("Software"), with or without modification, are permitted provided +that the following conditions are met: + +1. Redistributions in source form must retain copyright statements + and notices, + +2. Redistributions in binary form must reproduce applicable copyright + statements and notices, this list of conditions, and the following + disclaimer in the documentation and/or other materials provided + with the distribution, and + +3. Redistributions must contain a verbatim copy of this document. + +The OpenLDAP Foundation may revise this license from time to time. +Each revision is distinguished by a version number. You may use +this Software under terms of this license revision or under the +terms of any subsequent revision of the license. + +THIS SOFTWARE IS PROVIDED BY THE OPENLDAP FOUNDATION AND ITS +CONTRIBUTORS ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, +INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY +AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT +SHALL THE OPENLDAP FOUNDATION, ITS CONTRIBUTORS, OR THE AUTHOR(S) +OR OWNER(S) OF THE SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT, +INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, +BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN +ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +POSSIBILITY OF SUCH DAMAGE. + +The names of the authors and copyright holders must not be used in +advertising or otherwise to promote the sale, use or other dealing +in this Software without specific, written prior permission. Title +to copyright in this Software shall at all times remain with copyright +holders. + +OpenLDAP is a registered trademark of the OpenLDAP Foundation. + +Copyright 1999-2003 The OpenLDAP Foundation, Redwood City, +California, USA. All Rights Reserved. Permission to copy and +distribute verbatim copies of this document is granted. +------------------------------------------------------------------------- diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..db712e7 --- /dev/null +++ b/Makefile @@ -0,0 +1,24 @@ +# See LICENSE for licensing information. + +MODULE = emdb + +DIALYZER = dialyzer +REBAR = rebar + +.PHONY: build clean + +all: ebin priv build + +ebin: + @mkdir -p $@ + +priv: + @mkdir -p $@ + +build: + @$(REBAR) compile + +clean: + @$(REBAR) clean + @rm -f *~ */*~ erl_crash.dump + @rm -rf ebin priv diff --git a/README.md b/README.md index f68134e..c774e6f 100644 --- a/README.md +++ b/README.md @@ -1,4 +1,95 @@ -emdb -==== +EMDB ==== EMDB is a NIF library for the [Memory-Mapped Database](http://highlandsun.com/hyc/mdb/) database, aka. MDB. The main purpose of this package is to provide a **very fast** Riak [backend](http://wiki.basho.com/Storage-Backends.html). + +But this module could also be used as a general key-value store to replace: + +* [DETS](http://www.erlang.org/doc/man/dets.html) +* TokyoCabinet: [TCERL](http://code.google.com/p/tcerl/) +* [QDBM](http://fallabs.com/qdbm/) +* [Bitcask](https://github.com/basho/bitcask) +* [eLevelDB](https://github.com/basho/eleveldb) +* [BerkleyDB](http://www.oracle.com/technetwork/products/berkeleydb/overview/index.html) +* ... Requirements ------------ +* Erlang R14B04+ * GCC 4.2+ or MS VisualStudio 2010+ Build ----- $ make API --- + The following functions were implemented: + +* `open/1`: same as emdb:open(DBName, []). +* `open/2`: creates a new MDB database. This call also re-open an already existing one. The second argument lets you tune the database. See [mdb.h](http://gitorious.org/mdb/mdb/blobs/master/libraries/libmdb/mdb.h) +* `close/2`: closes the database +* `put/2`: inserts Key with value Val into the database. Assumes that the key is not present, 'key_exit' is returned otherwise. +* `get/1`: retrieves the value stored with Key in the database. +* `del/1`: Removes the key-value with key Key from database. +* `update/2`: inserts Key with value Val into the database if the key is not present, otherwise updates Key to value Val. +* `drop/1`: deletes all key-value pairs in the database. + + +Usage ----- $ make + +$ ./start.sh + + %% create a new database 1> {ok, Handle} = emdb:open("/tmp/emdb1"). + + %% insert the key <<"a">> with value <<"1">> 2> ok = Handle:put(<<"a">>, <<"1">>). + + %% try to re-insert the same key <<"a">> 3> key_exist = Handle:put(<<"a">>, <<"2">>). + + %% add a new key-value pair 4> ok = Handle:put(<<"b">>, <<"2">>). + + %% search a non-existing key <<"c">> 5> none = Handle:get(<<"c">>). + + %% retrieve the value for key <<"b">> 6> {ok, <<"2">>} = Handle:get(<<"b">>). + + %% retrieve the value for key <<"a">> 7> {ok, <<"1">>} = Handle:get(<<"a">>). + + %% delete key <<"b">> 8> ok = Handle:del(<<"b">>). + + %% search a non-existing key <<"b">> + 9> none = Handle:get(<<"b">>). + + %% delete a non-existing key <<"z">> 10> none = Handle:del(<<"z">>). + 11> {ok, <<"1">>} = Handle:get(<<"a">>). + %% update the value for key <<"a">> + 12> ok = Handle:update(<<"a">>, <<"7">>). + + %% check the new value for key <<"a">> + 13> {ok, <<"7">>} = Handle:get(<<"a">>). + + %% delete all key-value pairs in the database 14> ok = Handle:drop(). + + %% try to retrieve key <<"a">> value 15> none = Handle:get(<<"a">>). + + %% close the database 16> ok = Handle:close(). + + 17> q(). + + + Performance ----------- For maximum speed, this library use only binaries for both keys and values. + See the impressive [microbench](http://highlandsun.com/hyc/mdb/microbench/) against: + +* Google's LevelDB +* SQLite +* Kyoto TreeDB +* BerkeleyDB + +MDB performs better on 64-bit arch. + + +Supported OSes -------------- + +Should work on 32/64-bit architectures: + +* Linux +* OSX +* FreeBSD +* Windows + + TODO ---- + +* Unit tests * PropEr testing +* Bulk "writing" + +Volunteers are always welcome! Status +------ + #### Work in progress. Don't use it in production! + LICENSE ------- + EMDB is Copyright (C) 2012 by Aleph Archives, and released under the [OpenLDAP](http://www.OpenLDAP.org/license.html) License. -EMDB is a NIF library for the Memory-Mapped Database database \ No newline at end of file diff --git a/c_src/emdb_drv.c b/c_src/emdb_drv.c new file mode 100644 index 0000000..410a8b0 --- /dev/null +++ b/c_src/emdb_drv.c @@ -0,0 +1,469 @@ +/* ------------------------------------------------------------------------- + * This file is part of EMDB - Erlang MDB API + * + * Copyright (c) 2012 by Aleph Archives. All rights reserved. + * + * ------------------------------------------------------------------------- + * Redistribution and use in source and binary forms, with or without + * modification, are permitted only as authorized by the OpenLDAP + * Public License. + * + * A copy of this license is available in the file LICENSE in the + * top-level directory of the distribution or, alternatively, at + * . + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + * -------------------------------------------------------------------------*/ + +/* + * C headers + */ + +#include /* for MAXPATHLEN constant */ +#include /* for Erlang NIF interface */ +#include "uthash.h" /* for uthash */ +#include "mdb.h" /* for MDB interface */ + + + +#define FREE(p) (NULL == (p) ? 0 : (free(p), p = NULL)) + +#define FAIL_FAST(Error, Goto) \ + do{ \ + err = Error; \ + goto Goto; \ +}while(0) + + +struct emdb_map_t { + MDB_env * env; + MDB_dbi dbi; + + UT_hash_handle hh; +}; + + +static ERL_NIF_TERM atom_ok; +static ERL_NIF_TERM atom_none; + + +static struct emdb_map_t * emdb_map = NULL; + + +/* emdb ret */ +#define EMDB_RET_KEY_EXIST "key_exist" + +/* emdb errors */ +#define EMDB_MALLOC_ERR "error_malloc" +#define EMDB_CREATE_ERR "error_create" +#define EMDB_MAPSIZE_ERR "error_mapsize" +#define EMDB_OPEN_ERR "error_open" +#define EMDB_TXN_BEGIN_ERR "error_txn_begin" +#define EMDB_TXN_COMMIT_ERR "error_txn_commit" +#define EMDB_OPEN_DBI_ERR "error_open_dbi" +#define EMDB_INVALID_HANDLE_ERR "error_invalid_handle" +#define EMDB_PUT_ERR "error_put" +#define EMDB_UPDATE_ERR "error_update" +#define EMDB_KEY_NOT_FOUND "error_key_not_found" +#define EMDB_DROP_ERR "error_drop" + + + +/* + * Error handling callbacks + */ + +static void emdb_free (struct emdb_map_t * emdb_obj) +{ + FREE(emdb_obj); +} + + +/* + * Driver callbacks + */ + +static ERL_NIF_TERM emdb_open_nif (ErlNifEnv * env, + int argc, const ERL_NIF_TERM argv[]) +{ + char dirname [MAXPATHLEN]; + struct emdb_map_t * node; + MDB_txn * txn; + char * err; + + if (enif_get_string(env, argv[0], dirname, MAXPATHLEN, ERL_NIF_LATIN1) <= 0) + return enif_make_badarg(env); + + if(! (node = calloc(1, sizeof(struct emdb_map_t)))) + FAIL_FAST(EMDB_MALLOC_ERR, err3); + + if (mdb_env_create(& (node -> env))) + FAIL_FAST(EMDB_CREATE_ERR, err2); + + if (mdb_env_set_mapsize(node -> env, 10485760)) + FAIL_FAST(EMDB_MAPSIZE_ERR, err2); + + if (mdb_env_open(node -> env, dirname, MDB_FIXEDMAP, 0664)) + FAIL_FAST(EMDB_OPEN_ERR, err2); + + if (mdb_txn_begin(node -> env, NULL, 0, & txn)) + FAIL_FAST(EMDB_TXN_BEGIN_ERR, err2); + + if (mdb_open(txn, NULL, 0, & (node -> dbi))) + FAIL_FAST(EMDB_OPEN_DBI_ERR, err1); + + if (mdb_txn_commit(txn)) + FAIL_FAST(EMDB_TXN_COMMIT_ERR, err1); + + HASH_ADD_PTR(emdb_map, env, node); + + return enif_make_tuple(env, 2, + atom_ok, + enif_make_ulong(env, (unsigned long) node -> env)); + + err1: + mdb_txn_abort(txn); + err2: + mdb_env_close(node -> env); + err3: + emdb_free(node); + + return enif_make_atom(env, err); +} + +static ERL_NIF_TERM emdb_close_nif (ErlNifEnv * env, + int argc, const ERL_NIF_TERM argv[]) +{ + MDB_env * handle; + struct emdb_map_t * node; + unsigned long addr; + + if (! enif_get_ulong(env, argv[0], & addr)) + return enif_make_badarg(env); + + handle = (MDB_env *) addr; + + HASH_FIND_PTR(emdb_map, & handle, node); + if (NULL == node) + return enif_make_atom(env, EMDB_INVALID_HANDLE_ERR); + + HASH_DEL(emdb_map, node); + + mdb_env_close(node -> env); + emdb_free(node); + + return atom_ok; + } + + +static ERL_NIF_TERM emdb_put_nif (ErlNifEnv * env, + int argc, const ERL_NIF_TERM argv[]) +{ + ErlNifBinary key; + ErlNifBinary val; + + MDB_val mkey; + MDB_val mdata; + + MDB_env * handle; + MDB_txn * txn; + + struct emdb_map_t * node; + unsigned long addr; + char * err; + int ret; + + if (! enif_get_ulong(env, argv[0], & addr)) + return enif_make_badarg(env); + + handle = (MDB_env *) addr; + + HASH_FIND_PTR(emdb_map, & handle, node); + if (NULL == node) + return enif_make_atom(env, EMDB_INVALID_HANDLE_ERR); + + if (! enif_inspect_iolist_as_binary(env, argv[1], &key)) + return enif_make_badarg(env); + + if (! enif_inspect_iolist_as_binary(env, argv[2], &val)) + return enif_make_badarg(env); + + if (mdb_txn_begin(node -> env, NULL, 0, & txn)) + FAIL_FAST(EMDB_TXN_BEGIN_ERR, err2); + + mkey.mv_size = key.size; + mkey.mv_data = key.data; + mdata.mv_size = val.size; + mdata.mv_data = val.data; + + ret = mdb_put(txn, node -> dbi, & mkey, & mdata, MDB_NOOVERWRITE); + if (MDB_KEYEXIST == ret) + FAIL_FAST(EMDB_RET_KEY_EXIST, err1); + if (ret) + FAIL_FAST(EMDB_PUT_ERR, err1); + + if (mdb_txn_commit(txn)) + FAIL_FAST(EMDB_TXN_COMMIT_ERR, err1); + + return atom_ok; + + err1: + mdb_txn_abort(txn); + err2: + return enif_make_atom(env, err); +} + + +static ERL_NIF_TERM emdb_get_nif (ErlNifEnv * env, + int argc, const ERL_NIF_TERM argv[]) +{ + ErlNifBinary key; + ErlNifBinary val; + + MDB_val mkey; + MDB_val mdata; + + MDB_env * handle; + MDB_txn * txn; + + struct emdb_map_t * node; + char * err; + unsigned long addr; + + if (! enif_get_ulong(env, argv[0], & addr)) + return enif_make_badarg(env); + + handle = (MDB_env *) addr; + + HASH_FIND_PTR(emdb_map, & handle, node); + if (NULL == node) + return enif_make_atom(env, EMDB_INVALID_HANDLE_ERR); + + if (! enif_inspect_iolist_as_binary(env, argv[1], &key)) + return enif_make_badarg(env); + + mkey.mv_size = key.size; + mkey.mv_data = key.data; + + if (mdb_txn_begin(node -> env, NULL, 0, & txn)) + FAIL_FAST(EMDB_TXN_BEGIN_ERR, err1); + + if(mdb_get(txn, node -> dbi, & mkey, & mdata)) + { + mdb_txn_abort(txn); + return atom_none; + } + + if (! enif_alloc_binary(mdata.mv_size, & val)) + FAIL_FAST(EMDB_MALLOC_ERR, err2); + + memcpy(val.data, mdata.mv_data, mdata.mv_size); + + mdb_txn_abort(txn); + + return enif_make_tuple(env, 2, + atom_ok, + enif_make_binary(env, & val)); + + err2: + mdb_txn_abort(txn); + err1: + return enif_make_atom(env, err); +} + + +static ERL_NIF_TERM emdb_del_nif (ErlNifEnv * env, + int argc, const ERL_NIF_TERM argv[]) +{ + ErlNifBinary key; + + MDB_val mkey; + + MDB_env * handle; + MDB_txn * txn; + + struct emdb_map_t * node; + char * err; + unsigned long addr; + int ret; + + if (! enif_get_ulong(env, argv[0], & addr)) + return enif_make_badarg(env); + + handle = (MDB_env *) addr; + + HASH_FIND_PTR(emdb_map, & handle, node); + if (NULL == node) + return enif_make_atom(env, EMDB_INVALID_HANDLE_ERR); + + if (! enif_inspect_iolist_as_binary(env, argv[1], &key)) + return enif_make_badarg(env); + + mkey.mv_size = key.size; + mkey.mv_data = key.data; + + if (mdb_txn_begin(node -> env, NULL, 0, & txn)) + FAIL_FAST(EMDB_TXN_BEGIN_ERR, err); + + ret = mdb_del(txn, node -> dbi, & mkey, NULL); + + if (mdb_txn_commit(txn)) + FAIL_FAST(EMDB_TXN_COMMIT_ERR, err); + + if(ret) + return atom_none; + + return atom_ok; + + err: + return enif_make_atom(env, err); +} + + +static ERL_NIF_TERM emdb_update_nif (ErlNifEnv * env, + int argc, const ERL_NIF_TERM argv[]) +{ + ErlNifBinary key; + ErlNifBinary val; + + MDB_val mkey; + MDB_val mdata; + + MDB_env * handle; + MDB_txn * txn; + + struct emdb_map_t * node; + unsigned long addr; + char * err; + + if (! enif_get_ulong(env, argv[0], & addr)) + return enif_make_badarg(env); + + handle = (MDB_env *) addr; + + HASH_FIND_PTR(emdb_map, & handle, node); + if (NULL == node) + return enif_make_atom(env, EMDB_INVALID_HANDLE_ERR); + + if (! enif_inspect_iolist_as_binary(env, argv[1], &key)) + return enif_make_badarg(env); + + if (! enif_inspect_iolist_as_binary(env, argv[2], &val)) + return enif_make_badarg(env); + + if (mdb_txn_begin(node -> env, NULL, 0, & txn)) + FAIL_FAST(EMDB_TXN_BEGIN_ERR, err2); + + mkey.mv_size = key.size; + mkey.mv_data = key.data; + mdata.mv_size = val.size; + mdata.mv_data = val.data; + + if (mdb_put(txn, node -> dbi, & mkey, & mdata, 0)) + FAIL_FAST(EMDB_UPDATE_ERR, err1); + + if (mdb_txn_commit(txn)) + FAIL_FAST(EMDB_TXN_COMMIT_ERR, err1); + + return atom_ok; + + err1: + mdb_txn_abort(txn); + err2: + return enif_make_atom(env, err); +} + + +static ERL_NIF_TERM emdb_drop_nif (ErlNifEnv * env, + int argc, const ERL_NIF_TERM argv[]) +{ + MDB_env * handle; + MDB_txn * txn; + struct emdb_map_t * node; + unsigned long addr; + char * err; + int ret; + + if (! enif_get_ulong(env, argv[0], & addr)) + return enif_make_badarg(env); + + handle = (MDB_env *) addr; + + HASH_FIND_PTR(emdb_map, & handle, node); + if (NULL == node) + return enif_make_atom(env, EMDB_INVALID_HANDLE_ERR); + + if (mdb_txn_begin(node -> env, NULL, 0, & txn)) + FAIL_FAST(EMDB_TXN_BEGIN_ERR, err2); + + ret = mdb_drop(txn, node -> dbi, 0); + if (ret) + FAIL_FAST(EMDB_DROP_ERR, err1); + + if (mdb_txn_commit(txn)) + FAIL_FAST(EMDB_TXN_COMMIT_ERR, err1); + + return atom_ok; + + err1: + mdb_txn_abort(txn); + + err2: + return enif_make_atom(env, err); + } + + +static int emdb_load(ErlNifEnv* env, void** priv, ERL_NIF_TERM load_info) + { + atom_ok = enif_make_atom(env, "ok"); + atom_none = enif_make_atom(env, "none"); + + return (0); + } + +static int emdb_reload(ErlNifEnv* env, void** priv, ERL_NIF_TERM info) +{ + return (0); +} + + +static int emdb_upgrade(ErlNifEnv* env, void** priv, void** old_priv, ERL_NIF_TERM load_info) +{ + return (0); +} + + +static void emdb_unload(ErlNifEnv* env, void* priv) +{ + return; +} + + + +static ErlNifFunc nif_funcs [] = { + {"open", 1, emdb_open_nif}, + {"close", 1, emdb_close_nif}, + {"put", 3, emdb_put_nif}, + {"get", 2, emdb_get_nif}, + {"del", 2, emdb_del_nif}, + {"update", 3, emdb_update_nif}, + {"drop", 1, emdb_drop_nif} +}; + +/* driver entry point */ +ERL_NIF_INIT(emdb_drv, + nif_funcs, + & emdb_load, + & emdb_reload, + & emdb_upgrade, + & emdb_unload) diff --git a/c_src/mdb.c b/c_src/mdb.c new file mode 100644 index 0000000..42e3382 --- /dev/null +++ b/c_src/mdb.c @@ -0,0 +1,6763 @@ +/** @file mdb.c + * @brief memory-mapped database library + * + * A Btree-based database management library modeled loosely on the + * BerkeleyDB API, but much simplified. + */ +/* + * Copyright 2011-2012 Howard Chu, Symas Corp. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted only as authorized by the OpenLDAP + * Public License. + * + * A copy of this license is available in the file LICENSE in the + * top-level directory of the distribution or, alternatively, at + * . + * + * This code is derived from btree.c written by Martin Hedenfalk. + * + * Copyright (c) 2009, 2010 Martin Hedenfalk + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ +#include +#include +#include +#ifdef _WIN32 +#include +#else +#include +#include +#ifdef HAVE_SYS_FILE_H +#include +#endif +#include +#endif + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#if !(defined(BYTE_ORDER) || defined(__BYTE_ORDER)) +#include /* defines BYTE_ORDER on HPUX and Solaris */ +#endif + +#if defined(__APPLE__) || defined (BSD) +# define MDB_USE_POSIX_SEM 1 +# define MDB_FDATASYNC fsync +#elif defined(ANDROID) +# define MDB_FDATASYNC fsync +#endif + +#ifndef _WIN32 +#include +#ifdef MDB_USE_POSIX_SEM +#include +#endif +#endif + +#ifdef USE_VALGRIND +#include +#define VGMEMP_CREATE(h,r,z) VALGRIND_CREATE_MEMPOOL(h,r,z) +#define VGMEMP_ALLOC(h,a,s) VALGRIND_MEMPOOL_ALLOC(h,a,s) +#define VGMEMP_FREE(h,a) VALGRIND_MEMPOOL_FREE(h,a) +#define VGMEMP_DESTROY(h) VALGRIND_DESTROY_MEMPOOL(h) +#define VGMEMP_DEFINED(a,s) VALGRIND_MAKE_MEM_DEFINED(a,s) +#else +#define VGMEMP_CREATE(h,r,z) +#define VGMEMP_ALLOC(h,a,s) +#define VGMEMP_FREE(h,a) +#define VGMEMP_DESTROY(h) +#define VGMEMP_DEFINED(a,s) +#endif + +#ifndef BYTE_ORDER +# if (defined(_LITTLE_ENDIAN) || defined(_BIG_ENDIAN)) && !(defined(_LITTLE_ENDIAN) && defined(_BIG_ENDIAN)) +/* Solaris just defines one or the other */ +# define LITTLE_ENDIAN 1234 +# define BIG_ENDIAN 4321 +# ifdef _LITTLE_ENDIAN +# define BYTE_ORDER LITTLE_ENDIAN +# else +# define BYTE_ORDER BIG_ENDIAN +# endif +# else +# define BYTE_ORDER __BYTE_ORDER +# endif +#endif + +#ifndef LITTLE_ENDIAN +#define LITTLE_ENDIAN __LITTLE_ENDIAN +#endif +#ifndef BIG_ENDIAN +#define BIG_ENDIAN __BIG_ENDIAN +#endif + +#if defined(__i386) || defined(__x86_64) +#define MISALIGNED_OK 1 +#endif + +#include "mdb.h" +#include "midl.h" + +#if (BYTE_ORDER == LITTLE_ENDIAN) == (BYTE_ORDER == BIG_ENDIAN) +# error "Unknown or unsupported endianness (BYTE_ORDER)" +#elif (-6 & 5) || CHAR_BIT != 8 || UINT_MAX < 0xffffffff || ULONG_MAX % 0xFFFF +# error "Two's complement, reasonably sized integer types, please" +#endif + +/** @defgroup internal MDB Internals + * @{ + */ +/** @defgroup compat Windows Compatibility Macros + * A bunch of macros to minimize the amount of platform-specific ifdefs + * needed throughout the rest of the code. When the features this library + * needs are similar enough to POSIX to be hidden in a one-or-two line + * replacement, this macro approach is used. + * @{ + */ +#ifdef _WIN32 +#define pthread_t DWORD +#define pthread_mutex_t HANDLE +#define pthread_key_t DWORD +#define pthread_self() GetCurrentThreadId() +#define pthread_key_create(x,y) (*(x) = TlsAlloc()) +#define pthread_key_delete(x) TlsFree(x) +#define pthread_getspecific(x) TlsGetValue(x) +#define pthread_setspecific(x,y) TlsSetValue(x,y) +#define pthread_mutex_unlock(x) ReleaseMutex(x) +#define pthread_mutex_lock(x) WaitForSingleObject(x, INFINITE) +#define LOCK_MUTEX_R(env) pthread_mutex_lock((env)->me_rmutex) +#define UNLOCK_MUTEX_R(env) pthread_mutex_unlock((env)->me_rmutex) +#define LOCK_MUTEX_W(env) pthread_mutex_lock((env)->me_wmutex) +#define UNLOCK_MUTEX_W(env) pthread_mutex_unlock((env)->me_wmutex) +#define getpid() GetCurrentProcessId() +#define MDB_FDATASYNC(fd) (!FlushFileBuffers(fd)) +#define MDB_MSYNC(addr,len,flags) (!FlushViewOfFile(addr,len)) +#define ErrCode() GetLastError() +#define GET_PAGESIZE(x) {SYSTEM_INFO si; GetSystemInfo(&si); (x) = si.dwPageSize;} +#define close(fd) CloseHandle(fd) +#define munmap(ptr,len) UnmapViewOfFile(ptr) +#else + +#ifdef MDB_USE_POSIX_SEM + +#define LOCK_MUTEX_R(env) mdb_sem_wait((env)->me_rmutex) +#define UNLOCK_MUTEX_R(env) sem_post((env)->me_rmutex) +#define LOCK_MUTEX_W(env) mdb_sem_wait((env)->me_wmutex) +#define UNLOCK_MUTEX_W(env) sem_post((env)->me_wmutex) + +static int +mdb_sem_wait(sem_t *sem) +{ + int rc; + while ((rc = sem_wait(sem)) && (rc = errno) == EINTR) ; + return rc; +} + +#else + /** Lock the reader mutex. + */ +#define LOCK_MUTEX_R(env) pthread_mutex_lock(&(env)->me_txns->mti_mutex) + /** Unlock the reader mutex. + */ +#define UNLOCK_MUTEX_R(env) pthread_mutex_unlock(&(env)->me_txns->mti_mutex) + + /** Lock the writer mutex. + * Only a single write transaction is allowed at a time. Other writers + * will block waiting for this mutex. + */ +#define LOCK_MUTEX_W(env) pthread_mutex_lock(&(env)->me_txns->mti_wmutex) + /** Unlock the writer mutex. + */ +#define UNLOCK_MUTEX_W(env) pthread_mutex_unlock(&(env)->me_txns->mti_wmutex) +#endif /* MDB_USE_POSIX_SEM */ + + /** Get the error code for the last failed system function. + */ +#define ErrCode() errno + + /** An abstraction for a file handle. + * On POSIX systems file handles are small integers. On Windows + * they're opaque pointers. + */ +#define HANDLE int + + /** A value for an invalid file handle. + * Mainly used to initialize file variables and signify that they are + * unused. + */ +#define INVALID_HANDLE_VALUE (-1) + + /** Get the size of a memory page for the system. + * This is the basic size that the platform's memory manager uses, and is + * fundamental to the use of memory-mapped files. + */ +#define GET_PAGESIZE(x) ((x) = sysconf(_SC_PAGE_SIZE)) +#endif + +#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM) +#define MNAME_LEN 32 +#else +#define MNAME_LEN (sizeof(pthread_mutex_t)) +#endif + +/** @} */ + +#ifndef _WIN32 +/** A flag for opening a file and requesting synchronous data writes. + * This is only used when writing a meta page. It's not strictly needed; + * we could just do a normal write and then immediately perform a flush. + * But if this flag is available it saves us an extra system call. + * + * @note If O_DSYNC is undefined but exists in /usr/include, + * preferably set some compiler flag to get the definition. + * Otherwise compile with the less efficient -DMDB_DSYNC=O_SYNC. + */ +#ifndef MDB_DSYNC +# define MDB_DSYNC O_DSYNC +#endif +#endif + +/** Function for flushing the data of a file. Define this to fsync + * if fdatasync() is not supported. + */ +#ifndef MDB_FDATASYNC +# define MDB_FDATASYNC fdatasync +#endif + +#ifndef MDB_MSYNC +# define MDB_MSYNC(addr,len,flags) msync(addr,len,flags) +#endif + +#ifndef MS_SYNC +#define MS_SYNC 1 +#endif + +#ifndef MS_ASYNC +#define MS_ASYNC 0 +#endif + + /** A page number in the database. + * Note that 64 bit page numbers are overkill, since pages themselves + * already represent 12-13 bits of addressable memory, and the OS will + * always limit applications to a maximum of 63 bits of address space. + * + * @note In the #MDB_node structure, we only store 48 bits of this value, + * which thus limits us to only 60 bits of addressable data. + */ +typedef MDB_ID pgno_t; + + /** A transaction ID. + * See struct MDB_txn.mt_txnid for details. + */ +typedef MDB_ID txnid_t; + +/** @defgroup debug Debug Macros + * @{ + */ +#ifndef MDB_DEBUG + /** Enable debug output. + * Set this to 1 for copious tracing. Set to 2 to add dumps of all IDLs + * read from and written to the database (used for free space management). + */ +#define MDB_DEBUG 0 +#endif + +#if !(__STDC_VERSION__ >= 199901L || defined(__GNUC__)) +# define DPRINTF (void) /* Vararg macros may be unsupported */ +#elif MDB_DEBUG +static int mdb_debug; +static txnid_t mdb_debug_start; + + /** Print a debug message with printf formatting. */ +# define DPRINTF(fmt, ...) /**< Requires 2 or more args */ \ + ((void) ((mdb_debug) && \ + fprintf(stderr, "%s:%d " fmt "\n", __func__, __LINE__, __VA_ARGS__))) +#else +# define DPRINTF(fmt, ...) ((void) 0) +#endif + /** Print a debug string. + * The string is printed literally, with no format processing. + */ +#define DPUTS(arg) DPRINTF("%s", arg) +/** @} */ + + /** A default memory page size. + * The actual size is platform-dependent, but we use this for + * boot-strapping. We probably should not be using this any more. + * The #GET_PAGESIZE() macro is used to get the actual size. + * + * Note that we don't currently support Huge pages. On Linux, + * regular data files cannot use Huge pages, and in general + * Huge pages aren't actually pageable. We rely on the OS + * demand-pager to read our data and page it out when memory + * pressure from other processes is high. So until OSs have + * actual paging support for Huge pages, they're not viable. + */ +#define MDB_PAGESIZE 4096 + + /** The minimum number of keys required in a database page. + * Setting this to a larger value will place a smaller bound on the + * maximum size of a data item. Data items larger than this size will + * be pushed into overflow pages instead of being stored directly in + * the B-tree node. This value used to default to 4. With a page size + * of 4096 bytes that meant that any item larger than 1024 bytes would + * go into an overflow page. That also meant that on average 2-3KB of + * each overflow page was wasted space. The value cannot be lower than + * 2 because then there would no longer be a tree structure. With this + * value, items larger than 2KB will go into overflow pages, and on + * average only 1KB will be wasted. + */ +#define MDB_MINKEYS 2 + + /** A stamp that identifies a file as an MDB file. + * There's nothing special about this value other than that it is easily + * recognizable, and it will reflect any byte order mismatches. + */ +#define MDB_MAGIC 0xBEEFC0DE + + /** The version number for a database's file format. */ +#define MDB_VERSION 1 + + /** The maximum size of a key in the database. + * While data items have essentially unbounded size, we require that + * keys all fit onto a regular page. This limit could be raised a bit + * further if needed; to something just under #MDB_PAGESIZE / #MDB_MINKEYS. + */ +#define MAXKEYSIZE 511 + +#if MDB_DEBUG + /** A key buffer. + * @ingroup debug + * This is used for printing a hex dump of a key's contents. + */ +#define DKBUF char kbuf[(MAXKEYSIZE*2+1)] + /** Display a key in hex. + * @ingroup debug + * Invoke a function to display a key in hex. + */ +#define DKEY(x) mdb_dkey(x, kbuf) +#else +#define DKBUF typedef int dummy_kbuf /* so we can put ';' after */ +#define DKEY(x) 0 +#endif + + /** An invalid page number. + * Mainly used to denote an empty tree. + */ +#define P_INVALID (~(pgno_t)0) + + /** Test if a flag \b f is set in a flag word \b w. */ +#define F_ISSET(w, f) (((w) & (f)) == (f)) + + /** Used for offsets within a single page. + * Since memory pages are typically 4 or 8KB in size, 12-13 bits, + * this is plenty. + */ +typedef uint16_t indx_t; + + /** Default size of memory map. + * This is certainly too small for any actual applications. Apps should always set + * the size explicitly using #mdb_env_set_mapsize(). + */ +#define DEFAULT_MAPSIZE 1048576 + +/** @defgroup readers Reader Lock Table + * Readers don't acquire any locks for their data access. Instead, they + * simply record their transaction ID in the reader table. The reader + * mutex is needed just to find an empty slot in the reader table. The + * slot's address is saved in thread-specific data so that subsequent read + * transactions started by the same thread need no further locking to proceed. + * + * Since the database uses multi-version concurrency control, readers don't + * actually need any locking. This table is used to keep track of which + * readers are using data from which old transactions, so that we'll know + * when a particular old transaction is no longer in use. Old transactions + * that have discarded any data pages can then have those pages reclaimed + * for use by a later write transaction. + * + * The lock table is constructed such that reader slots are aligned with the + * processor's cache line size. Any slot is only ever used by one thread. + * This alignment guarantees that there will be no contention or cache + * thrashing as threads update their own slot info, and also eliminates + * any need for locking when accessing a slot. + * + * A writer thread will scan every slot in the table to determine the oldest + * outstanding reader transaction. Any freed pages older than this will be + * reclaimed by the writer. The writer doesn't use any locks when scanning + * this table. This means that there's no guarantee that the writer will + * see the most up-to-date reader info, but that's not required for correct + * operation - all we need is to know the upper bound on the oldest reader, + * we don't care at all about the newest reader. So the only consequence of + * reading stale information here is that old pages might hang around a + * while longer before being reclaimed. That's actually good anyway, because + * the longer we delay reclaiming old pages, the more likely it is that a + * string of contiguous pages can be found after coalescing old pages from + * many old transactions together. + * + * @todo We don't actually do such coalescing yet, we grab pages from one + * old transaction at a time. + * @{ + */ + /** Number of slots in the reader table. + * This value was chosen somewhat arbitrarily. 126 readers plus a + * couple mutexes fit exactly into 8KB on my development machine. + * Applications should set the table size using #mdb_env_set_maxreaders(). + */ +#define DEFAULT_READERS 126 + + /** The size of a CPU cache line in bytes. We want our lock structures + * aligned to this size to avoid false cache line sharing in the + * lock table. + * This value works for most CPUs. For Itanium this should be 128. + */ +#ifndef CACHELINE +#define CACHELINE 64 +#endif + + /** The information we store in a single slot of the reader table. + * In addition to a transaction ID, we also record the process and + * thread ID that owns a slot, so that we can detect stale information, + * e.g. threads or processes that went away without cleaning up. + * @note We currently don't check for stale records. We simply re-init + * the table when we know that we're the only process opening the + * lock file. + */ +typedef struct MDB_rxbody { + /** Current Transaction ID when this transaction began, or (txnid_t)-1. + * Multiple readers that start at the same time will probably have the + * same ID here. Again, it's not important to exclude them from + * anything; all we need to know is which version of the DB they + * started from so we can avoid overwriting any data used in that + * particular version. + */ + txnid_t mrb_txnid; + /** The process ID of the process owning this reader txn. */ + pid_t mrb_pid; + /** The thread ID of the thread owning this txn. */ + pthread_t mrb_tid; +} MDB_rxbody; + + /** The actual reader record, with cacheline padding. */ +typedef struct MDB_reader { + union { + MDB_rxbody mrx; + /** shorthand for mrb_txnid */ +#define mr_txnid mru.mrx.mrb_txnid +#define mr_pid mru.mrx.mrb_pid +#define mr_tid mru.mrx.mrb_tid + /** cache line alignment */ + char pad[(sizeof(MDB_rxbody)+CACHELINE-1) & ~(CACHELINE-1)]; + } mru; +} MDB_reader; + + /** The header for the reader table. + * The table resides in a memory-mapped file. (This is a different file + * than is used for the main database.) + * + * For POSIX the actual mutexes reside in the shared memory of this + * mapped file. On Windows, mutexes are named objects allocated by the + * kernel; we store the mutex names in this mapped file so that other + * processes can grab them. This same approach is also used on + * MacOSX/Darwin (using named semaphores) since MacOSX doesn't support + * process-shared POSIX mutexes. For these cases where a named object + * is used, the object name is derived from a 64 bit FNV hash of the + * environment pathname. As such, naming collisions are extremely + * unlikely. If a collision occurs, the results are unpredictable. + */ +typedef struct MDB_txbody { + /** Stamp identifying this as an MDB file. It must be set + * to #MDB_MAGIC. */ + uint32_t mtb_magic; + /** Version number of this lock file. Must be set to #MDB_VERSION. */ + uint32_t mtb_version; +#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM) + char mtb_rmname[MNAME_LEN]; +#else + /** Mutex protecting access to this table. + * This is the reader lock that #LOCK_MUTEX_R acquires. + */ + pthread_mutex_t mtb_mutex; +#endif + /** The ID of the last transaction committed to the database. + * This is recorded here only for convenience; the value can always + * be determined by reading the main database meta pages. + */ + txnid_t mtb_txnid; + /** The number of slots that have been used in the reader table. + * This always records the maximum count, it is not decremented + * when readers release their slots. + */ + unsigned mtb_numreaders; +} MDB_txbody; + + /** The actual reader table definition. */ +typedef struct MDB_txninfo { + union { + MDB_txbody mtb; +#define mti_magic mt1.mtb.mtb_magic +#define mti_version mt1.mtb.mtb_version +#define mti_mutex mt1.mtb.mtb_mutex +#define mti_rmname mt1.mtb.mtb_rmname +#define mti_txnid mt1.mtb.mtb_txnid +#define mti_numreaders mt1.mtb.mtb_numreaders + char pad[(sizeof(MDB_txbody)+CACHELINE-1) & ~(CACHELINE-1)]; + } mt1; + union { +#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM) + char mt2_wmname[MNAME_LEN]; +#define mti_wmname mt2.mt2_wmname +#else + pthread_mutex_t mt2_wmutex; +#define mti_wmutex mt2.mt2_wmutex +#endif + char pad[(MNAME_LEN+CACHELINE-1) & ~(CACHELINE-1)]; + } mt2; + MDB_reader mti_readers[1]; +} MDB_txninfo; +/** @} */ + +/** Common header for all page types. + * Overflow records occupy a number of contiguous pages with no + * headers on any page after the first. + */ +typedef struct MDB_page { +#define mp_pgno mp_p.p_pgno +#define mp_next mp_p.p_next + union { + pgno_t p_pgno; /**< page number */ + void * p_next; /**< for in-memory list of freed structs */ + } mp_p; + uint16_t mp_pad; +/** @defgroup mdb_page Page Flags + * @ingroup internal + * Flags for the page headers. + * @{ + */ +#define P_BRANCH 0x01 /**< branch page */ +#define P_LEAF 0x02 /**< leaf page */ +#define P_OVERFLOW 0x04 /**< overflow page */ +#define P_META 0x08 /**< meta page */ +#define P_DIRTY 0x10 /**< dirty page */ +#define P_LEAF2 0x20 /**< for #MDB_DUPFIXED records */ +#define P_SUBP 0x40 /**< for #MDB_DUPSORT sub-pages */ +/** @} */ + uint16_t mp_flags; /**< @ref mdb_page */ +#define mp_lower mp_pb.pb.pb_lower +#define mp_upper mp_pb.pb.pb_upper +#define mp_pages mp_pb.pb_pages + union { + struct { + indx_t pb_lower; /**< lower bound of free space */ + indx_t pb_upper; /**< upper bound of free space */ + } pb; + uint32_t pb_pages; /**< number of overflow pages */ + } mp_pb; + indx_t mp_ptrs[1]; /**< dynamic size */ +} MDB_page; + + /** Size of the page header, excluding dynamic data at the end */ +#define PAGEHDRSZ ((unsigned) offsetof(MDB_page, mp_ptrs)) + + /** Address of first usable data byte in a page, after the header */ +#define METADATA(p) ((void *)((char *)(p) + PAGEHDRSZ)) + + /** Number of nodes on a page */ +#define NUMKEYS(p) (((p)->mp_lower - PAGEHDRSZ) >> 1) + + /** The amount of space remaining in the page */ +#define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower) + + /** The percentage of space used in the page, in tenths of a percent. */ +#define PAGEFILL(env, p) (1000L * ((env)->me_psize - PAGEHDRSZ - SIZELEFT(p)) / \ + ((env)->me_psize - PAGEHDRSZ)) + /** The minimum page fill factor, in tenths of a percent. + * Pages emptier than this are candidates for merging. + */ +#define FILL_THRESHOLD 250 + + /** Test if a page is a leaf page */ +#define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF) + /** Test if a page is a LEAF2 page */ +#define IS_LEAF2(p) F_ISSET((p)->mp_flags, P_LEAF2) + /** Test if a page is a branch page */ +#define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH) + /** Test if a page is an overflow page */ +#define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW) + /** Test if a page is a sub page */ +#define IS_SUBP(p) F_ISSET((p)->mp_flags, P_SUBP) + + /** The number of overflow pages needed to store the given size. */ +#define OVPAGES(size, psize) ((PAGEHDRSZ-1 + (size)) / (psize) + 1) + + /** Header for a single key/data pair within a page. + * We guarantee 2-byte alignment for nodes. + */ +typedef struct MDB_node { + /** lo and hi are used for data size on leaf nodes and for + * child pgno on branch nodes. On 64 bit platforms, flags + * is also used for pgno. (Branch nodes have no flags). + * They are in host byte order in case that lets some + * accesses be optimized into a 32-bit word access. + */ +#define mn_lo mn_offset[BYTE_ORDER!=LITTLE_ENDIAN] +#define mn_hi mn_offset[BYTE_ORDER==LITTLE_ENDIAN] /**< part of dsize or pgno */ + unsigned short mn_offset[2]; /**< storage for #mn_lo and #mn_hi */ +/** @defgroup mdb_node Node Flags + * @ingroup internal + * Flags for node headers. + * @{ + */ +#define F_BIGDATA 0x01 /**< data put on overflow page */ +#define F_SUBDATA 0x02 /**< data is a sub-database */ +#define F_DUPDATA 0x04 /**< data has duplicates */ + +/** valid flags for #mdb_node_add() */ +#define NODE_ADD_FLAGS (F_DUPDATA|F_SUBDATA|MDB_RESERVE|MDB_APPEND) + +/** @} */ + unsigned short mn_flags; /**< @ref mdb_node */ + unsigned short mn_ksize; /**< key size */ + char mn_data[1]; /**< key and data are appended here */ +} MDB_node; + + /** Size of the node header, excluding dynamic data at the end */ +#define NODESIZE offsetof(MDB_node, mn_data) + + /** Bit position of top word in page number, for shifting mn_flags */ +#define PGNO_TOPWORD ((pgno_t)-1 > 0xffffffffu ? 32 : 0) + + /** Size of a node in a branch page with a given key. + * This is just the node header plus the key, there is no data. + */ +#define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size)) + + /** Size of a node in a leaf page with a given key and data. + * This is node header plus key plus data size. + */ +#define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size) + + /** Address of node \b i in page \b p */ +#define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i])) + + /** Address of the key for the node */ +#define NODEKEY(node) (void *)((node)->mn_data) + + /** Address of the data for a node */ +#define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize) + + /** Get the page number pointed to by a branch node */ +#define NODEPGNO(node) \ + ((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | \ + (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0)) + /** Set the page number in a branch node */ +#define SETPGNO(node,pgno) do { \ + (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; \ + if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0) + + /** Get the size of the data in a leaf node */ +#define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16)) + /** Set the size of the data for a leaf node */ +#define SETDSZ(node,size) do { \ + (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0) + /** The size of a key in a node */ +#define NODEKSZ(node) ((node)->mn_ksize) + + /** Copy a page number from src to dst */ +#ifdef MISALIGNED_OK +#define COPY_PGNO(dst,src) dst = src +#else +#if SIZE_MAX > 4294967295UL +#define COPY_PGNO(dst,src) do { \ + unsigned short *s, *d; \ + s = (unsigned short *)&(src); \ + d = (unsigned short *)&(dst); \ + *d++ = *s++; \ + *d++ = *s++; \ + *d++ = *s++; \ + *d = *s; \ +} while (0) +#else +#define COPY_PGNO(dst,src) do { \ + unsigned short *s, *d; \ + s = (unsigned short *)&(src); \ + d = (unsigned short *)&(dst); \ + *d++ = *s++; \ + *d = *s; \ +} while (0) +#endif +#endif + /** The address of a key in a LEAF2 page. + * LEAF2 pages are used for #MDB_DUPFIXED sorted-duplicate sub-DBs. + * There are no node headers, keys are stored contiguously. + */ +#define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks))) + + /** Set the \b node's key into \b key, if requested. */ +#define MDB_GET_KEY(node, key) { if ((key) != NULL) { \ + (key)->mv_size = NODEKSZ(node); (key)->mv_data = NODEKEY(node); } } + + /** Information about a single database in the environment. */ +typedef struct MDB_db { + uint32_t md_pad; /**< also ksize for LEAF2 pages */ + uint16_t md_flags; /**< @ref mdb_open */ + uint16_t md_depth; /**< depth of this tree */ + pgno_t md_branch_pages; /**< number of internal pages */ + pgno_t md_leaf_pages; /**< number of leaf pages */ + pgno_t md_overflow_pages; /**< number of overflow pages */ + size_t md_entries; /**< number of data items */ + pgno_t md_root; /**< the root page of this tree */ +} MDB_db; + + /** Handle for the DB used to track free pages. */ +#define FREE_DBI 0 + /** Handle for the default DB. */ +#define MAIN_DBI 1 + + /** Meta page content. */ +typedef struct MDB_meta { + /** Stamp identifying this as an MDB file. It must be set + * to #MDB_MAGIC. */ + uint32_t mm_magic; + /** Version number of this lock file. Must be set to #MDB_VERSION. */ + uint32_t mm_version; + void *mm_address; /**< address for fixed mapping */ + size_t mm_mapsize; /**< size of mmap region */ + MDB_db mm_dbs[2]; /**< first is free space, 2nd is main db */ + /** The size of pages used in this DB */ +#define mm_psize mm_dbs[0].md_pad + /** Any persistent environment flags. @ref mdb_env */ +#define mm_flags mm_dbs[0].md_flags + pgno_t mm_last_pg; /**< last used page in file */ + txnid_t mm_txnid; /**< txnid that committed this page */ +} MDB_meta; + + /** Buffer for a stack-allocated dirty page. + * The members define size and alignment, and silence type + * aliasing warnings. They are not used directly; that could + * mean incorrectly using several union members in parallel. + */ +typedef union MDB_pagebuf { + char mb_raw[MDB_PAGESIZE]; + MDB_page mb_page; + struct { + char mm_pad[PAGEHDRSZ]; + MDB_meta mm_meta; + } mb_metabuf; +} MDB_pagebuf; + + /** Auxiliary DB info. + * The information here is mostly static/read-only. There is + * only a single copy of this record in the environment. + */ +typedef struct MDB_dbx { + MDB_val md_name; /**< name of the database */ + MDB_cmp_func *md_cmp; /**< function for comparing keys */ + MDB_cmp_func *md_dcmp; /**< function for comparing data items */ + MDB_rel_func *md_rel; /**< user relocate function */ + void *md_relctx; /**< user-provided context for md_rel */ +} MDB_dbx; + + /** A database transaction. + * Every operation requires a transaction handle. + */ +struct MDB_txn { + MDB_txn *mt_parent; /**< parent of a nested txn */ + MDB_txn *mt_child; /**< nested txn under this txn */ + pgno_t mt_next_pgno; /**< next unallocated page */ + /** The ID of this transaction. IDs are integers incrementing from 1. + * Only committed write transactions increment the ID. If a transaction + * aborts, the ID may be re-used by the next writer. + */ + txnid_t mt_txnid; + MDB_env *mt_env; /**< the DB environment */ + /** The list of pages that became unused during this transaction. + */ + MDB_IDL mt_free_pgs; + union { + MDB_ID2L dirty_list; /**< modified pages */ + MDB_reader *reader; /**< this thread's slot in the reader table */ + } mt_u; + /** Array of records for each DB known in the environment. */ + MDB_dbx *mt_dbxs; + /** Array of MDB_db records for each known DB */ + MDB_db *mt_dbs; +/** @defgroup mt_dbflag Transaction DB Flags + * @ingroup internal + * @{ + */ +#define DB_DIRTY 0x01 /**< DB was written in this txn */ +#define DB_STALE 0x02 /**< DB record is older than txnID */ +/** @} */ + /** Array of cursors for each DB */ + MDB_cursor **mt_cursors; + /** Array of flags for each DB */ + unsigned char *mt_dbflags; + /** Number of DB records in use. This number only ever increments; + * we don't decrement it when individual DB handles are closed. + */ + MDB_dbi mt_numdbs; + +/** @defgroup mdb_txn Transaction Flags + * @ingroup internal + * @{ + */ +#define MDB_TXN_RDONLY 0x01 /**< read-only transaction */ +#define MDB_TXN_ERROR 0x02 /**< an error has occurred */ +/** @} */ + unsigned int mt_flags; /**< @ref mdb_txn */ + /** Tracks which of the two meta pages was used at the start + * of this transaction. + */ + unsigned int mt_toggle; +}; + +/** Enough space for 2^32 nodes with minimum of 2 keys per node. I.e., plenty. + * At 4 keys per node, enough for 2^64 nodes, so there's probably no need to + * raise this on a 64 bit machine. + */ +#define CURSOR_STACK 32 + +struct MDB_xcursor; + + /** Cursors are used for all DB operations */ +struct MDB_cursor { + /** Next cursor on this DB in this txn */ + MDB_cursor *mc_next; + /** Original cursor if this is a shadow */ + MDB_cursor *mc_orig; + /** Context used for databases with #MDB_DUPSORT, otherwise NULL */ + struct MDB_xcursor *mc_xcursor; + /** The transaction that owns this cursor */ + MDB_txn *mc_txn; + /** The database handle this cursor operates on */ + MDB_dbi mc_dbi; + /** The database record for this cursor */ + MDB_db *mc_db; + /** The database auxiliary record for this cursor */ + MDB_dbx *mc_dbx; + /** The @ref mt_dbflag for this database */ + unsigned char *mc_dbflag; + unsigned short mc_snum; /**< number of pushed pages */ + unsigned short mc_top; /**< index of top page, normally mc_snum-1 */ +/** @defgroup mdb_cursor Cursor Flags + * @ingroup internal + * Cursor state flags. + * @{ + */ +#define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */ +#define C_EOF 0x02 /**< No more data */ +#define C_SUB 0x04 /**< Cursor is a sub-cursor */ +#define C_SHADOW 0x08 /**< Cursor is a dup from a parent txn */ +#define C_ALLOCD 0x10 /**< Cursor was malloc'd */ +#define C_SPLITTING 0x20 /**< Cursor is in page_split */ +/** @} */ + unsigned int mc_flags; /**< @ref mdb_cursor */ + MDB_page *mc_pg[CURSOR_STACK]; /**< stack of pushed pages */ + indx_t mc_ki[CURSOR_STACK]; /**< stack of page indices */ +}; + + /** Context for sorted-dup records. + * We could have gone to a fully recursive design, with arbitrarily + * deep nesting of sub-databases. But for now we only handle these + * levels - main DB, optional sub-DB, sorted-duplicate DB. + */ +typedef struct MDB_xcursor { + /** A sub-cursor for traversing the Dup DB */ + MDB_cursor mx_cursor; + /** The database record for this Dup DB */ + MDB_db mx_db; + /** The auxiliary DB record for this Dup DB */ + MDB_dbx mx_dbx; + /** The @ref mt_dbflag for this Dup DB */ + unsigned char mx_dbflag; +} MDB_xcursor; + + /** A set of pages freed by an earlier transaction. */ +typedef struct MDB_oldpages { + /** Usually we only read one record from the FREEDB at a time, but + * in case we read more, this will chain them together. + */ + struct MDB_oldpages *mo_next; + /** The ID of the transaction in which these pages were freed. */ + txnid_t mo_txnid; + /** An #MDB_IDL of the pages */ + pgno_t mo_pages[1]; /* dynamic */ +} MDB_oldpages; + + /** The database environment. */ +struct MDB_env { + HANDLE me_fd; /**< The main data file */ + HANDLE me_lfd; /**< The lock file */ + HANDLE me_mfd; /**< just for writing the meta pages */ + /** Failed to update the meta page. Probably an I/O error. */ +#define MDB_FATAL_ERROR 0x80000000U + uint32_t me_flags; /**< @ref mdb_env */ + unsigned int me_psize; /**< size of a page, from #GET_PAGESIZE */ + unsigned int me_maxreaders; /**< size of the reader table */ + unsigned int me_numreaders; /**< max numreaders set by this env */ + MDB_dbi me_numdbs; /**< number of DBs opened */ + MDB_dbi me_maxdbs; /**< size of the DB table */ + pid_t me_pid; /**< process ID of this env */ + char *me_path; /**< path to the DB files */ + char *me_map; /**< the memory map of the data file */ + MDB_txninfo *me_txns; /**< the memory map of the lock file */ + MDB_meta *me_metas[2]; /**< pointers to the two meta pages */ + MDB_txn *me_txn; /**< current write transaction */ + size_t me_mapsize; /**< size of the data memory map */ + off_t me_size; /**< current file size */ + pgno_t me_maxpg; /**< me_mapsize / me_psize */ + txnid_t me_pgfirst; /**< ID of first old page record we used */ + txnid_t me_pglast; /**< ID of last old page record we used */ + MDB_dbx *me_dbxs; /**< array of static DB info */ + uint16_t *me_dbflags; /**< array of DB flags */ + MDB_oldpages *me_pghead; /**< list of old page records */ + MDB_oldpages *me_pgfree; /**< list of page records to free */ + pthread_key_t me_txkey; /**< thread-key for readers */ + MDB_page *me_dpages; /**< list of malloc'd blocks for re-use */ + /** IDL of pages that became unused in a write txn */ + MDB_IDL me_free_pgs; + /** ID2L of pages that were written during a write txn */ + MDB_ID2 me_dirty_list[MDB_IDL_UM_SIZE]; +#ifdef _WIN32 + HANDLE me_rmutex; /* Windows mutexes don't reside in shared mem */ + HANDLE me_wmutex; +#elif defined(MDB_USE_POSIX_SEM) + sem_t *me_rmutex; /* Shared mutexes are not supported */ + sem_t *me_wmutex; +#endif +}; + /** max number of pages to commit in one writev() call */ +#define MDB_COMMIT_PAGES 64 +#if defined(IOV_MAX) && IOV_MAX < MDB_COMMIT_PAGES +#undef MDB_COMMIT_PAGES +#define MDB_COMMIT_PAGES IOV_MAX +#endif + +static int mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp); +static int mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp); +static int mdb_page_touch(MDB_cursor *mc); + +static int mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp); +static int mdb_page_search_root(MDB_cursor *mc, + MDB_val *key, int modify); +#define MDB_PS_MODIFY 1 +#define MDB_PS_ROOTONLY 2 +static int mdb_page_search(MDB_cursor *mc, + MDB_val *key, int flags); +static int mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst); + +#define MDB_SPLIT_REPLACE MDB_APPENDDUP /**< newkey is not new */ +static int mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, + pgno_t newpgno, unsigned int nflags); + +static int mdb_env_read_header(MDB_env *env, MDB_meta *meta); +static int mdb_env_pick_meta(const MDB_env *env); +static int mdb_env_write_meta(MDB_txn *txn); +static void mdb_env_close0(MDB_env *env, int excl); + +static MDB_node *mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp); +static int mdb_node_add(MDB_cursor *mc, indx_t indx, + MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags); +static void mdb_node_del(MDB_page *mp, indx_t indx, int ksize); +static void mdb_node_shrink(MDB_page *mp, indx_t indx); +static int mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst); +static int mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data); +static size_t mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data); +static size_t mdb_branch_size(MDB_env *env, MDB_val *key); + +static int mdb_rebalance(MDB_cursor *mc); +static int mdb_update_key(MDB_page *mp, indx_t indx, MDB_val *key); + +static void mdb_cursor_pop(MDB_cursor *mc); +static int mdb_cursor_push(MDB_cursor *mc, MDB_page *mp); + +static int mdb_cursor_del0(MDB_cursor *mc, MDB_node *leaf); +static int mdb_cursor_sibling(MDB_cursor *mc, int move_right); +static int mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op); +static int mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op); +static int mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op, + int *exactp); +static int mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data); +static int mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data); + +static void mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx); +static void mdb_xcursor_init0(MDB_cursor *mc); +static void mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node); + +static int mdb_drop0(MDB_cursor *mc, int subs); +static void mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi); + +/** @cond */ +static MDB_cmp_func mdb_cmp_memn, mdb_cmp_memnr, mdb_cmp_int, mdb_cmp_cint, mdb_cmp_long; +/** @endcond */ + +#ifdef _WIN32 +static SECURITY_DESCRIPTOR mdb_null_sd; +static SECURITY_ATTRIBUTES mdb_all_sa; +static int mdb_sec_inited; +#endif + +/** Return the library version info. */ +char * +mdb_version(int *major, int *minor, int *patch) +{ + if (major) *major = MDB_VERSION_MAJOR; + if (minor) *minor = MDB_VERSION_MINOR; + if (patch) *patch = MDB_VERSION_PATCH; + return MDB_VERSION_STRING; +} + +/** Table of descriptions for MDB @ref errors */ +static char *const mdb_errstr[] = { + "MDB_KEYEXIST: Key/data pair already exists", + "MDB_NOTFOUND: No matching key/data pair found", + "MDB_PAGE_NOTFOUND: Requested page not found", + "MDB_CORRUPTED: Located page was wrong type", + "MDB_PANIC: Update of meta page failed", + "MDB_VERSION_MISMATCH: Database environment version mismatch", + "MDB_INVALID: File is not an MDB file", + "MDB_MAP_FULL: Environment mapsize limit reached", + "MDB_DBS_FULL: Environment maxdbs limit reached", + "MDB_READERS_FULL: Environment maxreaders limit reached", + "MDB_TLS_FULL: Thread-local storage keys full - too many environments open", + "MDB_TXN_FULL: Nested transaction has too many dirty pages - transaction too big", + "MDB_CURSOR_FULL: Internal error - cursor stack limit reached", + "MDB_PAGE_FULL: Internal error - page has no more space" +}; + +char * +mdb_strerror(int err) +{ + int i; + if (!err) + return ("Successful return: 0"); + + if (err >= MDB_KEYEXIST && err <= MDB_LAST_ERRCODE) { + i = err - MDB_KEYEXIST; + return mdb_errstr[i]; + } + + return strerror(err); +} + +#if MDB_DEBUG +/** Display a key in hexadecimal and return the address of the result. + * @param[in] key the key to display + * @param[in] buf the buffer to write into. Should always be #DKBUF. + * @return The key in hexadecimal form. + */ +char * +mdb_dkey(MDB_val *key, char *buf) +{ + char *ptr = buf; + unsigned char *c = key->mv_data; + unsigned int i; + if (key->mv_size > MAXKEYSIZE) + return "MAXKEYSIZE"; + /* may want to make this a dynamic check: if the key is mostly + * printable characters, print it as-is instead of converting to hex. + */ +#if 1 + buf[0] = '\0'; + for (i=0; imv_size; i++) + ptr += sprintf(ptr, "%02x", *c++); +#else + sprintf(buf, "%.*s", key->mv_size, key->mv_data); +#endif + return buf; +} + +/** Display all the keys in the page. */ +static void +mdb_page_list(MDB_page *mp) +{ + MDB_node *node; + unsigned int i, nkeys, nsize; + MDB_val key; + DKBUF; + + nkeys = NUMKEYS(mp); + fprintf(stderr, "numkeys %d\n", nkeys); + for (i=0; imn_ksize; + key.mv_data = node->mn_data; + nsize = NODESIZE + NODEKSZ(node) + sizeof(indx_t); + if (F_ISSET(node->mn_flags, F_BIGDATA)) + nsize += sizeof(pgno_t); + else + nsize += NODEDSZ(node); + fprintf(stderr, "key %d: nsize %d, %s\n", i, nsize, DKEY(&key)); + } +} + +void +mdb_cursor_chk(MDB_cursor *mc) +{ + unsigned int i; + MDB_node *node; + MDB_page *mp; + + if (!mc->mc_snum && !(mc->mc_flags & C_INITIALIZED)) return; + for (i=0; imc_top; i++) { + mp = mc->mc_pg[i]; + node = NODEPTR(mp, mc->mc_ki[i]); + if (NODEPGNO(node) != mc->mc_pg[i+1]->mp_pgno) + printf("oops!\n"); + } + if (mc->mc_ki[i] >= NUMKEYS(mc->mc_pg[i])) + printf("ack!\n"); +} +#endif + +#if MDB_DEBUG > 2 +/** Count all the pages in each DB and in the freelist + * and make sure it matches the actual number of pages + * being used. + */ +static void mdb_audit(MDB_txn *txn) +{ + MDB_cursor mc; + MDB_val key, data; + MDB_ID freecount, count; + MDB_dbi i; + int rc; + + freecount = 0; + mdb_cursor_init(&mc, txn, FREE_DBI, NULL); + while ((rc = mdb_cursor_get(&mc, &key, &data, MDB_NEXT)) == 0) + freecount += *(MDB_ID *)data.mv_data; + + count = 0; + for (i = 0; imt_numdbs; i++) { + MDB_xcursor mx, *mxp; + mxp = (txn->mt_dbs[i].md_flags & MDB_DUPSORT) ? &mx : NULL; + mdb_cursor_init(&mc, txn, i, mxp); + if (txn->mt_dbs[i].md_root == P_INVALID) + continue; + count += txn->mt_dbs[i].md_branch_pages + + txn->mt_dbs[i].md_leaf_pages + + txn->mt_dbs[i].md_overflow_pages; + if (txn->mt_dbs[i].md_flags & MDB_DUPSORT) { + mdb_page_search(&mc, NULL, 0); + do { + unsigned j; + MDB_page *mp; + mp = mc.mc_pg[mc.mc_top]; + for (j=0; jmn_flags & F_SUBDATA) { + MDB_db db; + memcpy(&db, NODEDATA(leaf), sizeof(db)); + count += db.md_branch_pages + db.md_leaf_pages + + db.md_overflow_pages; + } + } + } + while (mdb_cursor_sibling(&mc, 1) == 0); + } + } + if (freecount + count + 2 /* metapages */ != txn->mt_next_pgno) { + fprintf(stderr, "audit: %lu freecount: %lu count: %lu total: %lu next_pgno: %lu\n", + txn->mt_txnid, freecount, count+2, freecount+count+2, txn->mt_next_pgno); + } +} +#endif + +int +mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b) +{ + return txn->mt_dbxs[dbi].md_cmp(a, b); +} + +int +mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b) +{ + if (txn->mt_dbxs[dbi].md_dcmp) + return txn->mt_dbxs[dbi].md_dcmp(a, b); + else + return EINVAL; /* too bad you can't distinguish this from a valid result */ +} + +/** Allocate a single page. + * Re-use old malloc'd pages first, otherwise just malloc. + */ +static MDB_page * +mdb_page_malloc(MDB_cursor *mc) { + MDB_page *ret; + size_t sz = mc->mc_txn->mt_env->me_psize; + if ((ret = mc->mc_txn->mt_env->me_dpages) != NULL) { + VGMEMP_ALLOC(mc->mc_txn->mt_env, ret, sz); + VGMEMP_DEFINED(ret, sizeof(ret->mp_next)); + mc->mc_txn->mt_env->me_dpages = ret->mp_next; + } else if ((ret = malloc(sz)) != NULL) { + VGMEMP_ALLOC(mc->mc_txn->mt_env, ret, sz); + } + return ret; +} + +/** Allocate pages for writing. + * If there are free pages available from older transactions, they + * will be re-used first. Otherwise a new page will be allocated. + * @param[in] mc cursor A cursor handle identifying the transaction and + * database for which we are allocating. + * @param[in] num the number of pages to allocate. + * @param[out] mp Address of the allocated page(s). Requests for multiple pages + * will always be satisfied by a single contiguous chunk of memory. + * @return 0 on success, non-zero on failure. + */ +static int +mdb_page_alloc(MDB_cursor *mc, int num, MDB_page **mp) +{ + MDB_txn *txn = mc->mc_txn; + MDB_page *np; + pgno_t pgno = P_INVALID; + MDB_ID2 mid; + int rc; + + *mp = NULL; + /* The free list won't have any content at all until txn 2 has + * committed. The pages freed by txn 2 will be unreferenced + * after txn 3 commits, and so will be safe to re-use in txn 4. + */ + if (txn->mt_txnid > 3) { + + if (!txn->mt_env->me_pghead && + txn->mt_dbs[FREE_DBI].md_root != P_INVALID) { + /* See if there's anything in the free DB */ + int j; + MDB_reader *r; + MDB_cursor m2; + MDB_node *leaf; + MDB_val data; + txnid_t *kptr, last; + + mdb_cursor_init(&m2, txn, FREE_DBI, NULL); + if (!txn->mt_env->me_pgfirst) { + mdb_page_search(&m2, NULL, 0); + leaf = NODEPTR(m2.mc_pg[m2.mc_top], 0); + kptr = (txnid_t *)NODEKEY(leaf); + last = *kptr; + } else { + MDB_val key; + int exact; +again: + exact = 0; + last = txn->mt_env->me_pglast + 1; + leaf = NULL; + key.mv_data = &last; + key.mv_size = sizeof(last); + rc = mdb_cursor_set(&m2, &key, &data, MDB_SET, &exact); + if (rc) + goto none; + last = *(txnid_t *)key.mv_data; + } + + /* Unusable if referred by a meta page or reader... */ + j = 1; + if (last < txn->mt_txnid-1) { + j = txn->mt_env->me_txns->mti_numreaders; + r = txn->mt_env->me_txns->mti_readers + j; + for (j = -j; j && (lastmt_env->me_pgfirst) { + mdb_node_read(txn, leaf, &data); + } + txn->mt_env->me_pglast = last; + if (!txn->mt_env->me_pgfirst) + txn->mt_env->me_pgfirst = last; + idl = (MDB_ID *) data.mv_data; + /* We might have a zero-length IDL due to freelist growth + * during a prior commit + */ + if (!idl[0]) goto again; + mop = malloc(sizeof(MDB_oldpages) + MDB_IDL_SIZEOF(idl) - sizeof(pgno_t)); + if (!mop) + return ENOMEM; + mop->mo_next = txn->mt_env->me_pghead; + mop->mo_txnid = last; + txn->mt_env->me_pghead = mop; + memcpy(mop->mo_pages, idl, MDB_IDL_SIZEOF(idl)); + +#if MDB_DEBUG > 1 + { + unsigned int i; + DPRINTF("IDL read txn %zu root %zu num %zu", + mop->mo_txnid, txn->mt_dbs[FREE_DBI].md_root, idl[0]); + for (i=0; imt_env->me_pghead) { + MDB_oldpages *mop = txn->mt_env->me_pghead; + if (num > 1) { + /* FIXME: For now, always use fresh pages. We + * really ought to search the free list for a + * contiguous range. + */ + ; + } else { + /* peel pages off tail, so we only have to truncate the list */ + pgno = MDB_IDL_LAST(mop->mo_pages); + if (MDB_IDL_IS_RANGE(mop->mo_pages)) { + mop->mo_pages[2]++; + if (mop->mo_pages[2] > mop->mo_pages[1]) + mop->mo_pages[0] = 0; + } else { + mop->mo_pages[0]--; + } + if (MDB_IDL_IS_ZERO(mop->mo_pages)) { + txn->mt_env->me_pghead = mop->mo_next; + if (mc->mc_dbi == FREE_DBI) { + mop->mo_next = txn->mt_env->me_pgfree; + txn->mt_env->me_pgfree = mop; + } else { + free(mop); + } + } + } + } + } + + if (pgno == P_INVALID) { + /* DB size is maxed out */ + if (txn->mt_next_pgno + num >= txn->mt_env->me_maxpg) { + DPUTS("DB size maxed out"); + return MDB_MAP_FULL; + } + } + if (txn->mt_env->me_flags & MDB_WRITEMAP) { + if (pgno == P_INVALID) { + pgno = txn->mt_next_pgno; + txn->mt_next_pgno += num; + } + np = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno); + np->mp_pgno = pgno; + } else { + if (txn->mt_env->me_dpages && num == 1) { + np = txn->mt_env->me_dpages; + VGMEMP_ALLOC(txn->mt_env, np, txn->mt_env->me_psize); + VGMEMP_DEFINED(np, sizeof(np->mp_next)); + txn->mt_env->me_dpages = np->mp_next; + } else { + size_t sz = txn->mt_env->me_psize * num; + if ((np = malloc(sz)) == NULL) + return ENOMEM; + VGMEMP_ALLOC(txn->mt_env, np, sz); + } + if (pgno == P_INVALID) { + np->mp_pgno = txn->mt_next_pgno; + txn->mt_next_pgno += num; + } else { + np->mp_pgno = pgno; + } + } + mid.mid = np->mp_pgno; + mid.mptr = np; + if (txn->mt_env->me_flags & MDB_WRITEMAP) { + mdb_mid2l_append(txn->mt_u.dirty_list, &mid); + } else { + mdb_mid2l_insert(txn->mt_u.dirty_list, &mid); + } + *mp = np; + + return MDB_SUCCESS; +} + +/** Copy a page: avoid copying unused portions of the page. + * @param[in] dst page to copy into + * @param[in] src page to copy from + */ +static void +mdb_page_copy(MDB_page *dst, MDB_page *src, unsigned int psize) +{ + dst->mp_flags = src->mp_flags | P_DIRTY; + dst->mp_pages = src->mp_pages; + + if (IS_LEAF2(src)) { + memcpy(dst->mp_ptrs, src->mp_ptrs, psize - PAGEHDRSZ - SIZELEFT(src)); + } else { + unsigned int i, nkeys = NUMKEYS(src); + for (i=0; imp_ptrs[i] = src->mp_ptrs[i]; + memcpy((char *)dst+src->mp_upper, (char *)src+src->mp_upper, + psize - src->mp_upper); + } +} + +/** Touch a page: make it dirty and re-insert into tree with updated pgno. + * @param[in] mc cursor pointing to the page to be touched + * @return 0 on success, non-zero on failure. + */ +static int +mdb_page_touch(MDB_cursor *mc) +{ + MDB_page *mp = mc->mc_pg[mc->mc_top]; + pgno_t pgno; + int rc; + + if (!F_ISSET(mp->mp_flags, P_DIRTY)) { + MDB_page *np; + if ((rc = mdb_page_alloc(mc, 1, &np))) + return rc; + DPRINTF("touched db %u page %zu -> %zu", mc->mc_dbi, mp->mp_pgno, np->mp_pgno); + assert(mp->mp_pgno != np->mp_pgno); + mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno); + if (SIZELEFT(mp)) { + /* If page isn't full, just copy the used portion */ + mdb_page_copy(np, mp, mc->mc_txn->mt_env->me_psize); + } else { + pgno = np->mp_pgno; + memcpy(np, mp, mc->mc_txn->mt_env->me_psize); + np->mp_pgno = pgno; + np->mp_flags |= P_DIRTY; + } + mp = np; + +finish: + /* Adjust other cursors pointing to mp */ + if (mc->mc_flags & C_SUB) { + MDB_cursor *m2, *m3; + MDB_dbi dbi = mc->mc_dbi-1; + + for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { + if (m2 == mc) continue; + m3 = &m2->mc_xcursor->mx_cursor; + if (m3->mc_snum < mc->mc_snum) continue; + if (m3->mc_pg[mc->mc_top] == mc->mc_pg[mc->mc_top]) { + m3->mc_pg[mc->mc_top] = mp; + } + } + } else { + MDB_cursor *m2; + + for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) { + if (m2 == mc || m2->mc_snum < mc->mc_snum) continue; + if (m2->mc_pg[mc->mc_top] == mc->mc_pg[mc->mc_top]) { + m2->mc_pg[mc->mc_top] = mp; + } + } + } + mc->mc_pg[mc->mc_top] = mp; + /** If this page has a parent, update the parent to point to + * this new page. + */ + if (mc->mc_top) + SETPGNO(NODEPTR(mc->mc_pg[mc->mc_top-1], mc->mc_ki[mc->mc_top-1]), mp->mp_pgno); + else + mc->mc_db->md_root = mp->mp_pgno; + } else if (mc->mc_txn->mt_parent) { + MDB_page *np; + MDB_ID2 mid; + /* If txn has a parent, make sure the page is in our + * dirty list. + */ + if (mc->mc_txn->mt_u.dirty_list[0].mid) { + unsigned x = mdb_mid2l_search(mc->mc_txn->mt_u.dirty_list, mp->mp_pgno); + if (x <= mc->mc_txn->mt_u.dirty_list[0].mid && + mc->mc_txn->mt_u.dirty_list[x].mid == mp->mp_pgno) { + if (mc->mc_txn->mt_u.dirty_list[x].mptr != mp) { + mp = mc->mc_txn->mt_u.dirty_list[x].mptr; + mc->mc_pg[mc->mc_top] = mp; + } + return 0; + } + } + /* No - copy it */ + np = mdb_page_malloc(mc); + if (!np) + return ENOMEM; + memcpy(np, mp, mc->mc_txn->mt_env->me_psize); + mid.mid = np->mp_pgno; + mid.mptr = np; + mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &mid); + mp = np; + goto finish; + } + return 0; +} + +int +mdb_env_sync(MDB_env *env, int force) +{ + int rc = 0; + if (force || !F_ISSET(env->me_flags, MDB_NOSYNC)) { + if (env->me_flags & MDB_WRITEMAP) { + int flags = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC; + if (MDB_MSYNC(env->me_map, env->me_mapsize, flags)) + rc = ErrCode(); +#ifdef _WIN32 + else if (flags == MS_SYNC && MDB_FDATASYNC(env->me_fd)) + rc = ErrCode(); +#endif + } else { + if (MDB_FDATASYNC(env->me_fd)) + rc = ErrCode(); + } + } + return rc; +} + +/** Make shadow copies of all of parent txn's cursors */ +static int +mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst) +{ + MDB_cursor *mc, *m2; + unsigned int i, j, size; + + for (i=0;imt_numdbs; i++) { + if (src->mt_cursors[i]) { + size = sizeof(MDB_cursor); + if (src->mt_cursors[i]->mc_xcursor) + size += sizeof(MDB_xcursor); + for (m2 = src->mt_cursors[i]; m2; m2=m2->mc_next) { + mc = malloc(size); + if (!mc) + return ENOMEM; + mc->mc_orig = m2; + mc->mc_txn = dst; + mc->mc_dbi = i; + mc->mc_db = &dst->mt_dbs[i]; + mc->mc_dbx = m2->mc_dbx; + mc->mc_dbflag = &dst->mt_dbflags[i]; + mc->mc_snum = m2->mc_snum; + mc->mc_top = m2->mc_top; + mc->mc_flags = m2->mc_flags | C_SHADOW; + for (j=0; jmc_snum; j++) { + mc->mc_pg[j] = m2->mc_pg[j]; + mc->mc_ki[j] = m2->mc_ki[j]; + } + if (m2->mc_xcursor) { + MDB_xcursor *mx, *mx2; + mx = (MDB_xcursor *)(mc+1); + mc->mc_xcursor = mx; + mx2 = m2->mc_xcursor; + mx->mx_db = mx2->mx_db; + mx->mx_dbx = mx2->mx_dbx; + mx->mx_dbflag = mx2->mx_dbflag; + mx->mx_cursor.mc_txn = dst; + mx->mx_cursor.mc_dbi = mx2->mx_cursor.mc_dbi; + mx->mx_cursor.mc_db = &mx->mx_db; + mx->mx_cursor.mc_dbx = &mx->mx_dbx; + mx->mx_cursor.mc_dbflag = &mx->mx_dbflag; + mx->mx_cursor.mc_snum = mx2->mx_cursor.mc_snum; + mx->mx_cursor.mc_top = mx2->mx_cursor.mc_top; + mx->mx_cursor.mc_flags = mx2->mx_cursor.mc_flags | C_SHADOW; + for (j=0; jmx_cursor.mc_snum; j++) { + mx->mx_cursor.mc_pg[j] = mx2->mx_cursor.mc_pg[j]; + mx->mx_cursor.mc_ki[j] = mx2->mx_cursor.mc_ki[j]; + } + } else { + mc->mc_xcursor = NULL; + } + mc->mc_next = dst->mt_cursors[i]; + dst->mt_cursors[i] = mc; + } + } + } + return MDB_SUCCESS; +} + +/** Merge shadow cursors back into parent's */ +static void +mdb_cursor_merge(MDB_txn *txn) +{ + MDB_dbi i; + for (i=0; imt_numdbs; i++) { + if (txn->mt_cursors[i]) { + MDB_cursor *mc; + while ((mc = txn->mt_cursors[i])) { + txn->mt_cursors[i] = mc->mc_next; + if (mc->mc_flags & C_SHADOW) { + MDB_cursor *m2 = mc->mc_orig; + unsigned int j; + m2->mc_snum = mc->mc_snum; + m2->mc_top = mc->mc_top; + for (j=0; jmc_snum; j++) { + m2->mc_pg[j] = mc->mc_pg[j]; + m2->mc_ki[j] = mc->mc_ki[j]; + } + } + if (mc->mc_flags & C_ALLOCD) + free(mc); + } + } + } +} + +static void +mdb_txn_reset0(MDB_txn *txn); + +/** Common code for #mdb_txn_begin() and #mdb_txn_renew(). + * @param[in] txn the transaction handle to initialize + * @return 0 on success, non-zero on failure. This can only + * fail for read-only transactions, and then only if the + * reader table is full. + */ +static int +mdb_txn_renew0(MDB_txn *txn) +{ + MDB_env *env = txn->mt_env; + unsigned int i; + + /* Setup db info */ + txn->mt_numdbs = env->me_numdbs; + txn->mt_dbxs = env->me_dbxs; /* mostly static anyway */ + + if (txn->mt_flags & MDB_TXN_RDONLY) { + MDB_reader *r = pthread_getspecific(env->me_txkey); + if (!r) { + pid_t pid = env->me_pid; + pthread_t tid = pthread_self(); + + LOCK_MUTEX_R(env); + for (i=0; ime_txns->mti_numreaders; i++) + if (env->me_txns->mti_readers[i].mr_pid == 0) + break; + if (i == env->me_maxreaders) { + UNLOCK_MUTEX_R(env); + return MDB_READERS_FULL; + } + env->me_txns->mti_readers[i].mr_pid = pid; + env->me_txns->mti_readers[i].mr_tid = tid; + if (i >= env->me_txns->mti_numreaders) + env->me_txns->mti_numreaders = i+1; + /* Save numreaders for un-mutexed mdb_env_close() */ + env->me_numreaders = env->me_txns->mti_numreaders; + UNLOCK_MUTEX_R(env); + r = &env->me_txns->mti_readers[i]; + pthread_setspecific(env->me_txkey, r); + } + txn->mt_txnid = r->mr_txnid = env->me_txns->mti_txnid; + txn->mt_toggle = txn->mt_txnid & 1; + txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1; + txn->mt_u.reader = r; + } else { + LOCK_MUTEX_W(env); + + txn->mt_txnid = env->me_txns->mti_txnid; + txn->mt_toggle = txn->mt_txnid & 1; + txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1; + txn->mt_txnid++; +#if MDB_DEBUG + if (txn->mt_txnid == mdb_debug_start) + mdb_debug = 1; +#endif + txn->mt_u.dirty_list = env->me_dirty_list; + txn->mt_u.dirty_list[0].mid = 0; + txn->mt_free_pgs = env->me_free_pgs; + txn->mt_free_pgs[0] = 0; + env->me_txn = txn; + } + + /* Copy the DB info and flags */ + memcpy(txn->mt_dbs, env->me_metas[txn->mt_toggle]->mm_dbs, 2 * sizeof(MDB_db)); + for (i=2; imt_numdbs; i++) + txn->mt_dbs[i].md_flags = env->me_dbflags[i]; + txn->mt_dbflags[0] = txn->mt_dbflags[1] = 0; + if (txn->mt_numdbs > 2) + memset(txn->mt_dbflags+2, DB_STALE, txn->mt_numdbs-2); + + return MDB_SUCCESS; +} + +int +mdb_txn_renew(MDB_txn *txn) +{ + int rc; + + if (! (txn && txn->mt_flags & MDB_TXN_RDONLY)) + return EINVAL; + + if (txn->mt_env->me_flags & MDB_FATAL_ERROR) { + DPUTS("environment had fatal error, must shutdown!"); + return MDB_PANIC; + } + + rc = mdb_txn_renew0(txn); + if (rc == MDB_SUCCESS) { + DPRINTF("renew txn %zu%c %p on mdbenv %p, root page %zu", + txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', + (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root); + } + return rc; +} + +int +mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **ret) +{ + MDB_txn *txn; + int rc, size; + + if (env->me_flags & MDB_FATAL_ERROR) { + DPUTS("environment had fatal error, must shutdown!"); + return MDB_PANIC; + } + if ((env->me_flags & MDB_RDONLY) && !(flags & MDB_RDONLY)) + return EACCES; + if (parent) { + /* Nested transactions: Max 1 child, write txns only, no writemap */ + if (parent->mt_child || + (flags & MDB_RDONLY) || (parent->mt_flags & MDB_TXN_RDONLY) || + (env->me_flags & MDB_WRITEMAP)) + { + return EINVAL; + } + } + size = sizeof(MDB_txn) + env->me_maxdbs * (sizeof(MDB_db)+1); + if (!(flags & MDB_RDONLY)) + size += env->me_maxdbs * sizeof(MDB_cursor *); + + if ((txn = calloc(1, size)) == NULL) { + DPRINTF("calloc: %s", strerror(ErrCode())); + return ENOMEM; + } + txn->mt_dbs = (MDB_db *)(txn+1); + if (flags & MDB_RDONLY) { + txn->mt_flags |= MDB_TXN_RDONLY; + txn->mt_dbflags = (unsigned char *)(txn->mt_dbs + env->me_maxdbs); + } else { + txn->mt_cursors = (MDB_cursor **)(txn->mt_dbs + env->me_maxdbs); + txn->mt_dbflags = (unsigned char *)(txn->mt_cursors + env->me_maxdbs); + } + txn->mt_env = env; + + if (parent) { + txn->mt_free_pgs = mdb_midl_alloc(); + if (!txn->mt_free_pgs) { + free(txn); + return ENOMEM; + } + txn->mt_u.dirty_list = malloc(sizeof(MDB_ID2)*MDB_IDL_UM_SIZE); + if (!txn->mt_u.dirty_list) { + free(txn->mt_free_pgs); + free(txn); + return ENOMEM; + } + txn->mt_txnid = parent->mt_txnid; + txn->mt_toggle = parent->mt_toggle; + txn->mt_u.dirty_list[0].mid = 0; + txn->mt_free_pgs[0] = 0; + txn->mt_next_pgno = parent->mt_next_pgno; + parent->mt_child = txn; + txn->mt_parent = parent; + txn->mt_numdbs = parent->mt_numdbs; + txn->mt_dbxs = parent->mt_dbxs; + memcpy(txn->mt_dbs, parent->mt_dbs, txn->mt_numdbs * sizeof(MDB_db)); + memcpy(txn->mt_dbflags, parent->mt_dbflags, txn->mt_numdbs); + mdb_cursor_shadow(parent, txn); + rc = 0; + } else { + rc = mdb_txn_renew0(txn); + } + if (rc) + free(txn); + else { + *ret = txn; + DPRINTF("begin txn %zu%c %p on mdbenv %p, root page %zu", + txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', + (void *) txn, (void *) env, txn->mt_dbs[MAIN_DBI].md_root); + } + + return rc; +} + +/** Common code for #mdb_txn_reset() and #mdb_txn_abort(). + * @param[in] txn the transaction handle to reset + */ +static void +mdb_txn_reset0(MDB_txn *txn) +{ + MDB_env *env = txn->mt_env; + + if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) { + txn->mt_u.reader->mr_txnid = (txnid_t)-1; + } else { + MDB_oldpages *mop; + MDB_page *dp; + unsigned int i; + + /* close(free) all cursors */ + for (i=0; imt_numdbs; i++) { + if (txn->mt_cursors[i]) { + MDB_cursor *mc; + while ((mc = txn->mt_cursors[i])) { + txn->mt_cursors[i] = mc->mc_next; + if (mc->mc_flags & C_ALLOCD) + free(mc); + } + } + } + + if (!(env->me_flags & MDB_WRITEMAP)) { + /* return all dirty pages to dpage list */ + for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) { + dp = txn->mt_u.dirty_list[i].mptr; + if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) { + dp->mp_next = txn->mt_env->me_dpages; + VGMEMP_FREE(txn->mt_env, dp); + txn->mt_env->me_dpages = dp; + } else { + /* large pages just get freed directly */ + VGMEMP_FREE(txn->mt_env, dp); + free(dp); + } + } + } + + if (txn->mt_parent) { + txn->mt_parent->mt_child = NULL; + mdb_midl_free(txn->mt_free_pgs); + free(txn->mt_u.dirty_list); + return; + } else { + if (mdb_midl_shrink(&txn->mt_free_pgs)) + env->me_free_pgs = txn->mt_free_pgs; + } + + while ((mop = txn->mt_env->me_pghead)) { + txn->mt_env->me_pghead = mop->mo_next; + free(mop); + } + txn->mt_env->me_pgfirst = 0; + txn->mt_env->me_pglast = 0; + + env->me_txn = NULL; + /* The writer mutex was locked in mdb_txn_begin. */ + UNLOCK_MUTEX_W(env); + } +} + +void +mdb_txn_reset(MDB_txn *txn) +{ + if (txn == NULL) + return; + + DPRINTF("reset txn %zu%c %p on mdbenv %p, root page %zu", + txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', + (void *) txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root); + + mdb_txn_reset0(txn); +} + +void +mdb_txn_abort(MDB_txn *txn) +{ + if (txn == NULL) + return; + + DPRINTF("abort txn %zu%c %p on mdbenv %p, root page %zu", + txn->mt_txnid, (txn->mt_flags & MDB_TXN_RDONLY) ? 'r' : 'w', + (void *)txn, (void *)txn->mt_env, txn->mt_dbs[MAIN_DBI].md_root); + + if (txn->mt_child) + mdb_txn_abort(txn->mt_child); + + mdb_txn_reset0(txn); + free(txn); +} + +int +mdb_txn_commit(MDB_txn *txn) +{ + int n, done; + unsigned int i; + ssize_t rc; + off_t size; + MDB_page *dp; + MDB_env *env; + pgno_t next, freecnt; + MDB_cursor mc; + + assert(txn != NULL); + assert(txn->mt_env != NULL); + + if (txn->mt_child) { + mdb_txn_commit(txn->mt_child); + txn->mt_child = NULL; + } + + env = txn->mt_env; + + if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) { + if (txn->mt_numdbs > env->me_numdbs) { + /* update the DB flags */ + MDB_dbi i; + for (i = env->me_numdbs; imt_numdbs; i++) + env->me_dbflags[i] = txn->mt_dbs[i].md_flags; + env->me_numdbs = i; + } + mdb_txn_abort(txn); + return MDB_SUCCESS; + } + + if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) { + DPUTS("error flag is set, can't commit"); + if (txn->mt_parent) + txn->mt_parent->mt_flags |= MDB_TXN_ERROR; + mdb_txn_abort(txn); + return EINVAL; + } + + /* Merge (and close) our cursors with parent's */ + mdb_cursor_merge(txn); + + if (txn->mt_parent) { + MDB_db *ip, *jp; + MDB_dbi i; + unsigned x, y; + MDB_ID2L dst, src; + + /* Update parent's DB table */ + ip = &txn->mt_parent->mt_dbs[2]; + jp = &txn->mt_dbs[2]; + for (i = 2; i < txn->mt_numdbs; i++) { + if (ip->md_root != jp->md_root) + *ip = *jp; + ip++; jp++; + } + txn->mt_parent->mt_numdbs = txn->mt_numdbs; + + /* Append our free list to parent's */ + mdb_midl_append_list(&txn->mt_parent->mt_free_pgs, + txn->mt_free_pgs); + mdb_midl_free(txn->mt_free_pgs); + + /* Merge our dirty list with parent's */ + dst = txn->mt_parent->mt_u.dirty_list; + src = txn->mt_u.dirty_list; + x = mdb_mid2l_search(dst, src[1].mid); + for (y=1; y<=src[0].mid; y++) { + while (x <= dst[0].mid && dst[x].mid != src[y].mid) x++; + if (x > dst[0].mid) + break; + free(dst[x].mptr); + dst[x].mptr = src[y].mptr; + } + x = dst[0].mid; + for (; y<=src[0].mid; y++) { + if (++x >= MDB_IDL_UM_MAX) { + mdb_txn_abort(txn); + return MDB_TXN_FULL; + } + dst[x] = src[y]; + } + dst[0].mid = x; + free(txn->mt_u.dirty_list); + txn->mt_parent->mt_child = NULL; + free(txn); + return MDB_SUCCESS; + } + + if (txn != env->me_txn) { + DPUTS("attempt to commit unknown transaction"); + mdb_txn_abort(txn); + return EINVAL; + } + + if (!txn->mt_u.dirty_list[0].mid) + goto done; + + DPRINTF("committing txn %zu %p on mdbenv %p, root page %zu", + txn->mt_txnid, (void *)txn, (void *)env, txn->mt_dbs[MAIN_DBI].md_root); + + /* Update DB root pointers. Their pages have already been + * touched so this is all in-place and cannot fail. + */ + if (txn->mt_numdbs > 2) { + MDB_dbi i; + MDB_val data; + data.mv_size = sizeof(MDB_db); + + mdb_cursor_init(&mc, txn, MAIN_DBI, NULL); + for (i = 2; i < txn->mt_numdbs; i++) { + if (txn->mt_dbflags[i] & DB_DIRTY) { + data.mv_data = &txn->mt_dbs[i]; + mdb_cursor_put(&mc, &txn->mt_dbxs[i].md_name, &data, 0); + } + } + } + + mdb_cursor_init(&mc, txn, FREE_DBI, NULL); + + /* should only be one record now */ + if (env->me_pghead) { + /* make sure first page of freeDB is touched and on freelist */ + mdb_page_search(&mc, NULL, MDB_PS_MODIFY); + } + + /* Delete IDLs we used from the free list */ + if (env->me_pgfirst) { + txnid_t cur; + MDB_val key; + int exact = 0; + + key.mv_size = sizeof(cur); + for (cur = env->me_pgfirst; cur <= env->me_pglast; cur++) { + key.mv_data = &cur; + + mdb_cursor_set(&mc, &key, NULL, MDB_SET, &exact); + rc = mdb_cursor_del(&mc, 0); + if (rc) { + mdb_txn_abort(txn); + return rc; + } + } + env->me_pgfirst = 0; + env->me_pglast = 0; + } + + /* save to free list */ +free2: + freecnt = txn->mt_free_pgs[0]; + if (!MDB_IDL_IS_ZERO(txn->mt_free_pgs)) { + MDB_val key, data; + + /* make sure last page of freeDB is touched and on freelist */ + key.mv_size = MAXKEYSIZE+1; + key.mv_data = NULL; + mdb_page_search(&mc, &key, MDB_PS_MODIFY); + + mdb_midl_sort(txn->mt_free_pgs); +#if MDB_DEBUG > 1 + { + unsigned int i; + MDB_IDL idl = txn->mt_free_pgs; + DPRINTF("IDL write txn %zu root %zu num %zu", + txn->mt_txnid, txn->mt_dbs[FREE_DBI].md_root, idl[0]); + for (i=0; imt_txnid; + data.mv_data = txn->mt_free_pgs; + /* The free list can still grow during this call, + * despite the pre-emptive touches above. So check + * and make sure the entire thing got written. + */ + do { + freecnt = txn->mt_free_pgs[0]; + data.mv_size = MDB_IDL_SIZEOF(txn->mt_free_pgs); + rc = mdb_cursor_put(&mc, &key, &data, 0); + if (rc) { + mdb_txn_abort(txn); + return rc; + } + } while (freecnt != txn->mt_free_pgs[0]); + } + /* should only be one record now */ +again: + if (env->me_pghead) { + MDB_val key, data; + MDB_oldpages *mop; + pgno_t orig; + txnid_t id; + + mop = env->me_pghead; + id = mop->mo_txnid; + key.mv_size = sizeof(id); + key.mv_data = &id; + data.mv_size = MDB_IDL_SIZEOF(mop->mo_pages); + data.mv_data = mop->mo_pages; + orig = mop->mo_pages[0]; + /* These steps may grow the freelist again + * due to freed overflow pages... + */ + mdb_cursor_put(&mc, &key, &data, 0); + if (mop == env->me_pghead && env->me_pghead->mo_txnid == id) { + /* could have been used again here */ + if (mop->mo_pages[0] != orig) { + data.mv_size = MDB_IDL_SIZEOF(mop->mo_pages); + data.mv_data = mop->mo_pages; + id = mop->mo_txnid; + mdb_cursor_put(&mc, &key, &data, 0); + } + env->me_pghead = NULL; + free(mop); + } else { + /* was completely used up */ + mdb_cursor_del(&mc, 0); + if (env->me_pghead) + goto again; + } + env->me_pgfirst = 0; + env->me_pglast = 0; + } + + while (env->me_pgfree) { + MDB_oldpages *mop = env->me_pgfree; + env->me_pgfree = mop->mo_next; + free(mop);; + } + + /* Check for growth of freelist again */ + if (freecnt != txn->mt_free_pgs[0]) + goto free2; + + if (!MDB_IDL_IS_ZERO(txn->mt_free_pgs)) { + if (mdb_midl_shrink(&txn->mt_free_pgs)) + env->me_free_pgs = txn->mt_free_pgs; + } + +#if MDB_DEBUG > 2 + mdb_audit(txn); +#endif + + if (env->me_flags & MDB_WRITEMAP) { + for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) { + dp = txn->mt_u.dirty_list[i].mptr; + /* clear dirty flag */ + dp->mp_flags &= ~P_DIRTY; + txn->mt_u.dirty_list[i].mid = 0; + } + txn->mt_u.dirty_list[0].mid = 0; + goto sync; + } + + /* Commit up to MDB_COMMIT_PAGES dirty pages to disk until done. + */ + next = 0; + i = 1; + do { +#ifdef _WIN32 + /* Windows actually supports scatter/gather I/O, but only on + * unbuffered file handles. Since we're relying on the OS page + * cache for all our data, that's self-defeating. So we just + * write pages one at a time. We use the ov structure to set + * the write offset, to at least save the overhead of a Seek + * system call. + */ + OVERLAPPED ov; + memset(&ov, 0, sizeof(ov)); + for (; i<=txn->mt_u.dirty_list[0].mid; i++) { + size_t wsize; + dp = txn->mt_u.dirty_list[i].mptr; + DPRINTF("committing page %zu", dp->mp_pgno); + size = dp->mp_pgno * env->me_psize; + ov.Offset = size & 0xffffffff; + ov.OffsetHigh = size >> 16; + ov.OffsetHigh >>= 16; + /* clear dirty flag */ + dp->mp_flags &= ~P_DIRTY; + wsize = env->me_psize; + if (IS_OVERFLOW(dp)) wsize *= dp->mp_pages; + rc = WriteFile(env->me_fd, dp, wsize, NULL, &ov); + if (!rc) { + n = ErrCode(); + DPRINTF("WriteFile: %d", n); + mdb_txn_abort(txn); + return n; + } + } + done = 1; +#else + struct iovec iov[MDB_COMMIT_PAGES]; + n = 0; + done = 1; + size = 0; + for (; i<=txn->mt_u.dirty_list[0].mid; i++) { + dp = txn->mt_u.dirty_list[i].mptr; + if (dp->mp_pgno != next) { + if (n) { + rc = writev(env->me_fd, iov, n); + if (rc != size) { + n = ErrCode(); + if (rc > 0) + DPUTS("short write, filesystem full?"); + else + DPRINTF("writev: %s", strerror(n)); + mdb_txn_abort(txn); + return n; + } + n = 0; + size = 0; + } + lseek(env->me_fd, dp->mp_pgno * env->me_psize, SEEK_SET); + next = dp->mp_pgno; + } + DPRINTF("committing page %zu", dp->mp_pgno); + iov[n].iov_len = env->me_psize; + if (IS_OVERFLOW(dp)) iov[n].iov_len *= dp->mp_pages; + iov[n].iov_base = (char *)dp; + size += iov[n].iov_len; + next = dp->mp_pgno + (IS_OVERFLOW(dp) ? dp->mp_pages : 1); + /* clear dirty flag */ + dp->mp_flags &= ~P_DIRTY; + if (++n >= MDB_COMMIT_PAGES) { + done = 0; + i++; + break; + } + } + + if (n == 0) + break; + + rc = writev(env->me_fd, iov, n); + if (rc != size) { + n = ErrCode(); + if (rc > 0) + DPUTS("short write, filesystem full?"); + else + DPRINTF("writev: %s", strerror(n)); + mdb_txn_abort(txn); + return n; + } +#endif + } while (!done); + + /* Drop the dirty pages. + */ + for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) { + dp = txn->mt_u.dirty_list[i].mptr; + if (!IS_OVERFLOW(dp) || dp->mp_pages == 1) { + dp->mp_next = txn->mt_env->me_dpages; + VGMEMP_FREE(txn->mt_env, dp); + txn->mt_env->me_dpages = dp; + } else { + VGMEMP_FREE(txn->mt_env, dp); + free(dp); + } + txn->mt_u.dirty_list[i].mid = 0; + } + txn->mt_u.dirty_list[0].mid = 0; + +sync: + if ((n = mdb_env_sync(env, 0)) != 0 || + (n = mdb_env_write_meta(txn)) != MDB_SUCCESS) { + mdb_txn_abort(txn); + return n; + } + +done: + env->me_txn = NULL; + if (txn->mt_numdbs > env->me_numdbs) { + /* update the DB flags */ + MDB_dbi i; + for (i = env->me_numdbs; imt_numdbs; i++) + env->me_dbflags[i] = txn->mt_dbs[i].md_flags; + env->me_numdbs = i; + } + + UNLOCK_MUTEX_W(env); + free(txn); + + return MDB_SUCCESS; +} + +/** Read the environment parameters of a DB environment before + * mapping it into memory. + * @param[in] env the environment handle + * @param[out] meta address of where to store the meta information + * @return 0 on success, non-zero on failure. + */ +static int +mdb_env_read_header(MDB_env *env, MDB_meta *meta) +{ + MDB_pagebuf pbuf; + MDB_page *p; + MDB_meta *m; + int rc, err; + + /* We don't know the page size yet, so use a minimum value. + */ + +#ifdef _WIN32 + if (!ReadFile(env->me_fd, &pbuf, MDB_PAGESIZE, (DWORD *)&rc, NULL) || rc == 0) +#else + if ((rc = read(env->me_fd, &pbuf, MDB_PAGESIZE)) == 0) +#endif + { + return ENOENT; + } + else if (rc != MDB_PAGESIZE) { + err = ErrCode(); + if (rc > 0) + err = MDB_INVALID; + DPRINTF("read: %s", strerror(err)); + return err; + } + + p = (MDB_page *)&pbuf; + + if (!F_ISSET(p->mp_flags, P_META)) { + DPRINTF("page %zu not a meta page", p->mp_pgno); + return MDB_INVALID; + } + + m = METADATA(p); + if (m->mm_magic != MDB_MAGIC) { + DPUTS("meta has invalid magic"); + return MDB_INVALID; + } + + if (m->mm_version != MDB_VERSION) { + DPRINTF("database is version %u, expected version %u", + m->mm_version, MDB_VERSION); + return MDB_VERSION_MISMATCH; + } + + memcpy(meta, m, sizeof(*m)); + return 0; +} + +/** Write the environment parameters of a freshly created DB environment. + * @param[in] env the environment handle + * @param[out] meta address of where to store the meta information + * @return 0 on success, non-zero on failure. + */ +static int +mdb_env_init_meta(MDB_env *env, MDB_meta *meta) +{ + MDB_page *p, *q; + MDB_meta *m; + int rc; + unsigned int psize; + + DPUTS("writing new meta page"); + + GET_PAGESIZE(psize); + + meta->mm_magic = MDB_MAGIC; + meta->mm_version = MDB_VERSION; + meta->mm_psize = psize; + meta->mm_last_pg = 1; + meta->mm_flags = env->me_flags & 0xffff; + meta->mm_flags |= MDB_INTEGERKEY; + meta->mm_dbs[0].md_root = P_INVALID; + meta->mm_dbs[1].md_root = P_INVALID; + + p = calloc(2, psize); + p->mp_pgno = 0; + p->mp_flags = P_META; + + m = METADATA(p); + memcpy(m, meta, sizeof(*meta)); + + q = (MDB_page *)((char *)p + psize); + + q->mp_pgno = 1; + q->mp_flags = P_META; + + m = METADATA(q); + memcpy(m, meta, sizeof(*meta)); + +#ifdef _WIN32 + { + DWORD len; + rc = WriteFile(env->me_fd, p, psize * 2, &len, NULL); + rc = (len == psize * 2) ? MDB_SUCCESS : ErrCode(); + } +#else + rc = write(env->me_fd, p, psize * 2); + rc = (rc == (int)psize * 2) ? MDB_SUCCESS : ErrCode(); +#endif + free(p); + return rc; +} + +/** Update the environment info to commit a transaction. + * @param[in] txn the transaction that's being committed + * @return 0 on success, non-zero on failure. + */ +static int +mdb_env_write_meta(MDB_txn *txn) +{ + MDB_env *env; + MDB_meta meta, metab; + off_t off; + int rc, len, toggle; + char *ptr; +#ifdef _WIN32 + OVERLAPPED ov; +#endif + + assert(txn != NULL); + assert(txn->mt_env != NULL); + + toggle = !txn->mt_toggle; + DPRINTF("writing meta page %d for root page %zu", + toggle, txn->mt_dbs[MAIN_DBI].md_root); + + env = txn->mt_env; + + if (env->me_flags & MDB_WRITEMAP) { + MDB_meta *mp = env->me_metas[toggle]; + mp->mm_dbs[0] = txn->mt_dbs[0]; + mp->mm_dbs[1] = txn->mt_dbs[1]; + mp->mm_last_pg = txn->mt_next_pgno - 1; + mp->mm_txnid = txn->mt_txnid; + if (!(env->me_flags & (MDB_NOMETASYNC|MDB_NOSYNC))) { + rc = (env->me_flags & MDB_MAPASYNC) ? MS_ASYNC : MS_SYNC; + ptr = env->me_map; + if (toggle) + ptr += env->me_psize; + if (MDB_MSYNC(ptr, env->me_psize, rc)) { + rc = ErrCode(); + goto fail; + } + } + goto done; + } + metab.mm_txnid = env->me_metas[toggle]->mm_txnid; + metab.mm_last_pg = env->me_metas[toggle]->mm_last_pg; + + ptr = (char *)&meta; + off = offsetof(MDB_meta, mm_dbs[0].md_depth); + len = sizeof(MDB_meta) - off; + + ptr += off; + meta.mm_dbs[0] = txn->mt_dbs[0]; + meta.mm_dbs[1] = txn->mt_dbs[1]; + meta.mm_last_pg = txn->mt_next_pgno - 1; + meta.mm_txnid = txn->mt_txnid; + + if (toggle) + off += env->me_psize; + off += PAGEHDRSZ; + + /* Write to the SYNC fd */ +#ifdef _WIN32 + { + memset(&ov, 0, sizeof(ov)); + ov.Offset = off; + WriteFile(env->me_mfd, ptr, len, (DWORD *)&rc, &ov); + } +#else + rc = pwrite(env->me_mfd, ptr, len, off); +#endif + if (rc != len) { + int r2; + rc = ErrCode(); + DPUTS("write failed, disk error?"); + /* On a failure, the pagecache still contains the new data. + * Write some old data back, to prevent it from being used. + * Use the non-SYNC fd; we know it will fail anyway. + */ + meta.mm_last_pg = metab.mm_last_pg; + meta.mm_txnid = metab.mm_txnid; +#ifdef _WIN32 + WriteFile(env->me_fd, ptr, len, NULL, &ov); +#else + r2 = pwrite(env->me_fd, ptr, len, off); +#endif +fail: + env->me_flags |= MDB_FATAL_ERROR; + return rc; + } +done: + /* Memory ordering issues are irrelevant; since the entire writer + * is wrapped by wmutex, all of these changes will become visible + * after the wmutex is unlocked. Since the DB is multi-version, + * readers will get consistent data regardless of how fresh or + * how stale their view of these values is. + */ + txn->mt_env->me_txns->mti_txnid = txn->mt_txnid; + + return MDB_SUCCESS; +} + +/** Check both meta pages to see which one is newer. + * @param[in] env the environment handle + * @return meta toggle (0 or 1). + */ +static int +mdb_env_pick_meta(const MDB_env *env) +{ + return (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid); +} + +int +mdb_env_create(MDB_env **env) +{ + MDB_env *e; + + e = calloc(1, sizeof(MDB_env)); + if (!e) + return ENOMEM; + + e->me_free_pgs = mdb_midl_alloc(); + if (!e->me_free_pgs) { + free(e); + return ENOMEM; + } + e->me_maxreaders = DEFAULT_READERS; + e->me_maxdbs = 2; + e->me_fd = INVALID_HANDLE_VALUE; + e->me_lfd = INVALID_HANDLE_VALUE; + e->me_mfd = INVALID_HANDLE_VALUE; +#ifdef MDB_USE_POSIX_SEM + e->me_rmutex = SEM_FAILED; + e->me_wmutex = SEM_FAILED; +#endif + e->me_pid = getpid(); + VGMEMP_CREATE(e,0,0); + *env = e; + return MDB_SUCCESS; +} + +int +mdb_env_set_mapsize(MDB_env *env, size_t size) +{ + if (env->me_map) + return EINVAL; + env->me_mapsize = size; + if (env->me_psize) + env->me_maxpg = env->me_mapsize / env->me_psize; + return MDB_SUCCESS; +} + +int +mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs) +{ + if (env->me_map) + return EINVAL; + env->me_maxdbs = dbs; + return MDB_SUCCESS; +} + +int +mdb_env_set_maxreaders(MDB_env *env, unsigned int readers) +{ + if (env->me_map || readers < 1) + return EINVAL; + env->me_maxreaders = readers; + return MDB_SUCCESS; +} + +int +mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers) +{ + if (!env || !readers) + return EINVAL; + *readers = env->me_maxreaders; + return MDB_SUCCESS; +} + +/** Further setup required for opening an MDB environment + */ +static int +mdb_env_open2(MDB_env *env, unsigned int flags) +{ + int i, newenv = 0, prot; + MDB_meta meta; + MDB_page *p; + + env->me_flags = flags; + + memset(&meta, 0, sizeof(meta)); + + if ((i = mdb_env_read_header(env, &meta)) != 0) { + if (i != ENOENT) + return i; + DPUTS("new mdbenv"); + newenv = 1; + } + + if (!env->me_mapsize) { + env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize; + } + +#ifdef _WIN32 + { + HANDLE mh; + LONG sizelo, sizehi; + sizelo = env->me_mapsize & 0xffffffff; + sizehi = env->me_mapsize >> 16; /* pointless on WIN32, only needed on W64 */ + sizehi >>= 16; + /* Windows won't create mappings for zero length files. + * Just allocate the maxsize right now. + */ + if (newenv) { + SetFilePointer(env->me_fd, sizelo, sizehi ? &sizehi : NULL, 0); + if (!SetEndOfFile(env->me_fd)) + return ErrCode(); + SetFilePointer(env->me_fd, 0, NULL, 0); + } + mh = CreateFileMapping(env->me_fd, NULL, flags & MDB_WRITEMAP ? + PAGE_READWRITE : PAGE_READONLY, + sizehi, sizelo, NULL); + if (!mh) + return ErrCode(); + env->me_map = MapViewOfFileEx(mh, flags & MDB_WRITEMAP ? + FILE_MAP_WRITE : FILE_MAP_READ, + 0, 0, env->me_mapsize, meta.mm_address); + CloseHandle(mh); + if (!env->me_map) + return ErrCode(); + } +#else + i = MAP_SHARED; + if (meta.mm_address && (flags & MDB_FIXEDMAP)) + i |= MAP_FIXED; + prot = PROT_READ; + if (flags & MDB_WRITEMAP) { + prot |= PROT_WRITE; + ftruncate(env->me_fd, env->me_mapsize); + } + env->me_map = mmap(meta.mm_address, env->me_mapsize, prot, i, + env->me_fd, 0); + if (env->me_map == MAP_FAILED) { + env->me_map = NULL; + return ErrCode(); + } +#endif + + if (newenv) { + meta.mm_mapsize = env->me_mapsize; + if (flags & MDB_FIXEDMAP) + meta.mm_address = env->me_map; + i = mdb_env_init_meta(env, &meta); + if (i != MDB_SUCCESS) { + return i; + } + } + env->me_psize = meta.mm_psize; + + env->me_maxpg = env->me_mapsize / env->me_psize; + + p = (MDB_page *)env->me_map; + env->me_metas[0] = METADATA(p); + env->me_metas[1] = (MDB_meta *)((char *)env->me_metas[0] + meta.mm_psize); + +#if MDB_DEBUG + { + int toggle = mdb_env_pick_meta(env); + MDB_db *db = &env->me_metas[toggle]->mm_dbs[MAIN_DBI]; + + DPRINTF("opened database version %u, pagesize %u", + env->me_metas[0]->mm_version, env->me_psize); + DPRINTF("using meta page %d", toggle); + DPRINTF("depth: %u", db->md_depth); + DPRINTF("entries: %zu", db->md_entries); + DPRINTF("branch pages: %zu", db->md_branch_pages); + DPRINTF("leaf pages: %zu", db->md_leaf_pages); + DPRINTF("overflow pages: %zu", db->md_overflow_pages); + DPRINTF("root: %zu", db->md_root); + } +#endif + + return MDB_SUCCESS; +} + + +/** Release a reader thread's slot in the reader lock table. + * This function is called automatically when a thread exits. + * @param[in] ptr This points to the slot in the reader lock table. + */ +static void +mdb_env_reader_dest(void *ptr) +{ + MDB_reader *reader = ptr; + + reader->mr_pid = 0; +} + +#ifdef _WIN32 +/** Junk for arranging thread-specific callbacks on Windows. This is + * necessarily platform and compiler-specific. Windows supports up + * to 1088 keys. Let's assume nobody opens more than 64 environments + * in a single process, for now. They can override this if needed. + */ +#ifndef MAX_TLS_KEYS +#define MAX_TLS_KEYS 64 +#endif +static pthread_key_t mdb_tls_keys[MAX_TLS_KEYS]; +static int mdb_tls_nkeys; + +static void NTAPI mdb_tls_callback(PVOID module, DWORD reason, PVOID ptr) +{ + int i; + switch(reason) { + case DLL_PROCESS_ATTACH: break; + case DLL_THREAD_ATTACH: break; + case DLL_THREAD_DETACH: + for (i=0; ime_txns->mti_txnid = env->me_metas[toggle]->mm_txnid; + +#ifdef _WIN32 + { + OVERLAPPED ov; + /* First acquire a shared lock. The Unlock will + * then release the existing exclusive lock. + */ + memset(&ov, 0, sizeof(ov)); + LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov); + UnlockFile(env->me_lfd, 0, 0, 1, 0); + *excl = 0; + } +#else + { + struct flock lock_info; + /* The shared lock replaces the existing lock */ + memset((void *)&lock_info, 0, sizeof(lock_info)); + lock_info.l_type = F_RDLCK; + lock_info.l_whence = SEEK_SET; + lock_info.l_start = 0; + lock_info.l_len = 1; + while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) && + (rc = ErrCode()) == EINTR) ; + *excl = rc ? -1 : 0; /* error may mean we lost the lock */ + } +#endif + + return rc; +} + +/** Try to get exlusive lock, otherwise shared. + * Maintain *excl = -1: no/unknown lock, 0: shared, 1: exclusive. + */ +static int +mdb_env_excl_lock(MDB_env *env, int *excl) +{ + int rc = 0; +#ifdef _WIN32 + if (LockFile(env->me_lfd, 0, 0, 1, 0)) { + *excl = 1; + } else { + OVERLAPPED ov; + memset(&ov, 0, sizeof(ov)); + if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) { + rc = ErrCode(); + } + } +#else + struct flock lock_info; + memset((void *)&lock_info, 0, sizeof(lock_info)); + lock_info.l_type = F_WRLCK; + lock_info.l_whence = SEEK_SET; + lock_info.l_start = 0; + lock_info.l_len = 1; + if (!fcntl(env->me_lfd, F_SETLK, &lock_info)) { + *excl = 1; + } else +# ifdef MDB_USE_POSIX_SEM + if (*excl < 0) /* always true when !MDB_USE_POSIX_SEM */ +# endif + { + lock_info.l_type = F_RDLCK; + while ((rc = fcntl(env->me_lfd, F_SETLKW, &lock_info)) && + (rc = ErrCode()) == EINTR) ; + if (rc == 0) + *excl = 0; + } +#endif + return rc; +} + +#if defined(_WIN32) || defined(MDB_USE_POSIX_SEM) +/* + * hash_64 - 64 bit Fowler/Noll/Vo-0 FNV-1a hash code + * + * @(#) $Revision: 5.1 $ + * @(#) $Id: hash_64a.c,v 5.1 2009/06/30 09:01:38 chongo Exp $ + * @(#) $Source: /usr/local/src/cmd/fnv/RCS/hash_64a.c,v $ + * + * http://www.isthe.com/chongo/tech/comp/fnv/index.html + * + *** + * + * Please do not copyright this code. This code is in the public domain. + * + * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO + * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF + * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR + * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + * PERFORMANCE OF THIS SOFTWARE. + * + * By: + * chongo /\oo/\ + * http://www.isthe.com/chongo/ + * + * Share and Enjoy! :-) + */ + +typedef unsigned long long mdb_hash_t; +#define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL) + +/** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer + * @param[in] str string to hash + * @param[in] hval initial value for hash + * @return 64 bit hash + * + * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the + * hval arg on the first call. + */ +static mdb_hash_t +mdb_hash_val(MDB_val *val, mdb_hash_t hval) +{ + unsigned char *s = (unsigned char *)val->mv_data; /* unsigned string */ + unsigned char *end = s + val->mv_size; + /* + * FNV-1a hash each octet of the string + */ + while (s < end) { + /* xor the bottom with the current octet */ + hval ^= (mdb_hash_t)*s++; + + /* multiply by the 64 bit FNV magic prime mod 2^64 */ + hval += (hval << 1) + (hval << 4) + (hval << 5) + + (hval << 7) + (hval << 8) + (hval << 40); + } + /* return our new hash value */ + return hval; +} + +/** Hash the string and output the hash in hex. + * @param[in] str string to hash + * @param[out] hexbuf an array of 17 chars to hold the hash + */ +static void +mdb_hash_hex(MDB_val *val, char *hexbuf) +{ + int i; + mdb_hash_t h = mdb_hash_val(val, MDB_HASH_INIT); + for (i=0; i<8; i++) { + hexbuf += sprintf(hexbuf, "%02x", (unsigned int)h & 0xff); + h >>= 8; + } +} +#endif + +/** Open and/or initialize the lock region for the environment. + * @param[in] env The MDB environment. + * @param[in] lpath The pathname of the file used for the lock region. + * @param[in] mode The Unix permissions for the file, if we create it. + * @param[out] excl Resulting file lock type: -1 none, 0 shared, 1 exclusive + * @return 0 on success, non-zero on failure. + */ +static int +mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl) +{ + int rc; + off_t size, rsize; + + *excl = -1; + +#ifdef _WIN32 + if ((env->me_lfd = CreateFile(lpath, GENERIC_READ|GENERIC_WRITE, + FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, + FILE_ATTRIBUTE_NORMAL, NULL)) == INVALID_HANDLE_VALUE) { + goto fail_errno; + } + /* Try to get exclusive lock. If we succeed, then + * nobody is using the lock region and we should initialize it. + */ + if ((rc = mdb_env_excl_lock(env, excl))) goto fail; + size = GetFileSize(env->me_lfd, NULL); + +#else +#if !(O_CLOEXEC) + { + int fdflags; + if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT, mode)) == -1) + goto fail_errno; + /* Lose record locks when exec*() */ + if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0) + fcntl(env->me_lfd, F_SETFD, fdflags); + } +#else /* O_CLOEXEC on Linux: Open file and set FD_CLOEXEC atomically */ + if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT|O_CLOEXEC, mode)) == -1) + goto fail_errno; +#endif + + /* Try to get exclusive lock. If we succeed, then + * nobody is using the lock region and we should initialize it. + */ + if ((rc = mdb_env_excl_lock(env, excl))) goto fail; + + size = lseek(env->me_lfd, 0, SEEK_END); +#endif + rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo); + if (size < rsize && *excl > 0) { +#ifdef _WIN32 + SetFilePointer(env->me_lfd, rsize, NULL, 0); + if (!SetEndOfFile(env->me_lfd)) goto fail_errno; +#else + if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno; +#endif + } else { + rsize = size; + size = rsize - sizeof(MDB_txninfo); + env->me_maxreaders = size/sizeof(MDB_reader) + 1; + } + { +#ifdef _WIN32 + HANDLE mh; + mh = CreateFileMapping(env->me_lfd, NULL, PAGE_READWRITE, + 0, 0, NULL); + if (!mh) goto fail_errno; + env->me_txns = MapViewOfFileEx(mh, FILE_MAP_WRITE, 0, 0, rsize, NULL); + CloseHandle(mh); + if (!env->me_txns) goto fail_errno; +#else + void *m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED, + env->me_lfd, 0); + if (m == MAP_FAILED) goto fail_errno; + env->me_txns = m; +#endif + } + if (*excl > 0) { +#ifdef _WIN32 + BY_HANDLE_FILE_INFORMATION stbuf; + struct { + DWORD volume; + DWORD nhigh; + DWORD nlow; + } idbuf; + MDB_val val; + char hexbuf[17]; + + if (!mdb_sec_inited) { + InitializeSecurityDescriptor(&mdb_null_sd, + SECURITY_DESCRIPTOR_REVISION); + SetSecurityDescriptorDacl(&mdb_null_sd, TRUE, 0, FALSE); + mdb_all_sa.nLength = sizeof(SECURITY_ATTRIBUTES); + mdb_all_sa.bInheritHandle = FALSE; + mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd; + mdb_sec_inited = 1; + } + GetFileInformationByHandle(env->me_lfd, &stbuf); + idbuf.volume = stbuf.dwVolumeSerialNumber; + idbuf.nhigh = stbuf.nFileIndexHigh; + idbuf.nlow = stbuf.nFileIndexLow; + val.mv_data = &idbuf; + val.mv_size = sizeof(idbuf); + mdb_hash_hex(&val, hexbuf); + sprintf(env->me_txns->mti_rmname, "Global\\MDBr%s", hexbuf); + sprintf(env->me_txns->mti_wmname, "Global\\MDBw%s", hexbuf); + env->me_rmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_rmname); + if (!env->me_rmutex) goto fail_errno; + env->me_wmutex = CreateMutex(&mdb_all_sa, FALSE, env->me_txns->mti_wmname); + if (!env->me_wmutex) goto fail_errno; +#elif defined(MDB_USE_POSIX_SEM) + struct stat stbuf; + struct { + dev_t dev; + ino_t ino; + } idbuf; + MDB_val val; + char hexbuf[17]; + + if (fstat(env->me_lfd, &stbuf)) goto fail_errno; + idbuf.dev = stbuf.st_dev; + idbuf.ino = stbuf.st_ino; + val.mv_data = &idbuf; + val.mv_size = sizeof(idbuf); + mdb_hash_hex(&val, hexbuf); + sprintf(env->me_txns->mti_rmname, "/MDBr%s", hexbuf); + sprintf(env->me_txns->mti_wmname, "/MDBw%s", hexbuf); + /* Clean up after a previous run, if needed: Try to + * remove both semaphores before doing anything else. + */ + sem_unlink(env->me_txns->mti_rmname); + sem_unlink(env->me_txns->mti_wmname); + env->me_rmutex = sem_open(env->me_txns->mti_rmname, + O_CREAT|O_EXCL, mode, 1); + if (env->me_rmutex == SEM_FAILED) goto fail_errno; + env->me_wmutex = sem_open(env->me_txns->mti_wmname, + O_CREAT|O_EXCL, mode, 1); + if (env->me_wmutex == SEM_FAILED) goto fail_errno; +#else /* MDB_USE_POSIX_SEM */ + pthread_mutexattr_t mattr; + + if ((rc = pthread_mutexattr_init(&mattr)) + || (rc = pthread_mutexattr_setpshared(&mattr, PTHREAD_PROCESS_SHARED)) + || (rc = pthread_mutex_init(&env->me_txns->mti_mutex, &mattr)) + || (rc = pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr))) + goto fail; + pthread_mutexattr_destroy(&mattr); +#endif /* _WIN32 || MDB_USE_POSIX_SEM */ + + env->me_txns->mti_version = MDB_VERSION; + env->me_txns->mti_magic = MDB_MAGIC; + env->me_txns->mti_txnid = 0; + env->me_txns->mti_numreaders = 0; + + } else { + if (env->me_txns->mti_magic != MDB_MAGIC) { + DPUTS("lock region has invalid magic"); + rc = MDB_INVALID; + goto fail; + } + if (env->me_txns->mti_version != MDB_VERSION) { + DPRINTF("lock region is version %u, expected version %u", + env->me_txns->mti_version, MDB_VERSION); + rc = MDB_VERSION_MISMATCH; + goto fail; + } + rc = ErrCode(); + if (rc != EACCES && rc != EAGAIN) { + goto fail; + } +#ifdef _WIN32 + env->me_rmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_rmname); + if (!env->me_rmutex) goto fail_errno; + env->me_wmutex = OpenMutex(SYNCHRONIZE, FALSE, env->me_txns->mti_wmname); + if (!env->me_wmutex) goto fail_errno; +#elif defined(MDB_USE_POSIX_SEM) + env->me_rmutex = sem_open(env->me_txns->mti_rmname, 0); + if (env->me_rmutex == SEM_FAILED) goto fail_errno; + env->me_wmutex = sem_open(env->me_txns->mti_wmname, 0); + if (env->me_wmutex == SEM_FAILED) goto fail_errno; +#endif + } + return MDB_SUCCESS; + +fail_errno: + rc = ErrCode(); +fail: + return rc; +} + + /** The name of the lock file in the DB environment */ +#define LOCKNAME "/lock.mdb" + /** The name of the data file in the DB environment */ +#define DATANAME "/data.mdb" + /** The suffix of the lock file when no subdir is used */ +#define LOCKSUFF "-lock" + +int +mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode) +{ + int oflags, rc, len, excl; + char *lpath, *dpath; + + if (env->me_fd != INVALID_HANDLE_VALUE) + return EINVAL; + + len = strlen(path); + if (flags & MDB_NOSUBDIR) { + rc = len + sizeof(LOCKSUFF) + len + 1; + } else { + rc = len + sizeof(LOCKNAME) + len + sizeof(DATANAME); + } + lpath = malloc(rc); + if (!lpath) + return ENOMEM; + if (flags & MDB_NOSUBDIR) { + dpath = lpath + len + sizeof(LOCKSUFF); + sprintf(lpath, "%s" LOCKSUFF, path); + strcpy(dpath, path); + } else { + dpath = lpath + len + sizeof(LOCKNAME); + sprintf(lpath, "%s" LOCKNAME, path); + sprintf(dpath, "%s" DATANAME, path); + } + + rc = mdb_env_setup_locks(env, lpath, mode, &excl); + if (rc) + goto leave; + + /* silently ignore WRITEMAP if we're only getting read access */ + if (F_ISSET(flags, MDB_RDONLY) && F_ISSET(flags, MDB_WRITEMAP)) + flags ^= MDB_WRITEMAP; + +#ifdef _WIN32 + if (F_ISSET(flags, MDB_RDONLY)) { + oflags = GENERIC_READ; + len = OPEN_EXISTING; + } else { + oflags = GENERIC_READ|GENERIC_WRITE; + len = OPEN_ALWAYS; + } + mode = FILE_ATTRIBUTE_NORMAL; + env->me_fd = CreateFile(dpath, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE, + NULL, len, mode, NULL); +#else + if (F_ISSET(flags, MDB_RDONLY)) + oflags = O_RDONLY; + else + oflags = O_RDWR | O_CREAT; + + env->me_fd = open(dpath, oflags, mode); +#endif + if (env->me_fd == INVALID_HANDLE_VALUE) { + rc = ErrCode(); + goto leave; + } + + if ((rc = mdb_env_open2(env, flags)) == MDB_SUCCESS) { + if (flags & (MDB_RDONLY|MDB_NOSYNC|MDB_NOMETASYNC|MDB_WRITEMAP)) { + env->me_mfd = env->me_fd; + } else { + /* synchronous fd for meta writes */ +#ifdef _WIN32 + env->me_mfd = CreateFile(dpath, oflags, + FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len, + mode | FILE_FLAG_WRITE_THROUGH, NULL); +#else + env->me_mfd = open(dpath, oflags | MDB_DSYNC, mode); +#endif + if (env->me_mfd == INVALID_HANDLE_VALUE) { + rc = ErrCode(); + goto leave; + } + } + DPRINTF("opened dbenv %p", (void *) env); + pthread_key_create(&env->me_txkey, mdb_env_reader_dest); + env->me_numdbs = 2; /* this notes that me_txkey was set */ +#ifdef _WIN32 + /* Windows TLS callbacks need help finding their TLS info. */ + if (mdb_tls_nkeys < MAX_TLS_KEYS) + mdb_tls_keys[mdb_tls_nkeys++] = env->me_txkey; + else { + rc = MDB_TLS_FULL; + goto leave; + } +#endif + if (excl > 0) { + rc = mdb_env_share_locks(env, &excl); + if (rc) + goto leave; + } + env->me_dbxs = calloc(env->me_maxdbs, sizeof(MDB_dbx)); + env->me_dbflags = calloc(env->me_maxdbs, sizeof(uint16_t)); + env->me_path = strdup(path); + if (!env->me_dbxs || !env->me_dbflags || !env->me_path) + rc = ENOMEM; + } + +leave: + if (rc) { + mdb_env_close0(env, excl); + } + free(lpath); + return rc; +} + +/** Destroy resources from mdb_env_open() and clear our readers */ +static void +mdb_env_close0(MDB_env *env, int excl) +{ + int i; + + if (env->me_lfd == INVALID_HANDLE_VALUE) /* 1st field to get inited */ + return; + + free(env->me_dbflags); + free(env->me_dbxs); + free(env->me_path); + + if (env->me_numdbs) { + pthread_key_delete(env->me_txkey); +#ifdef _WIN32 + /* Delete our key from the global list */ + for (i=0; ime_txkey) { + mdb_tls_keys[i] = mdb_tls_keys[mdb_tls_nkeys-1]; + mdb_tls_nkeys--; + break; + } +#endif + } + + if (env->me_map) { + munmap(env->me_map, env->me_mapsize); + } + if (env->me_mfd != env->me_fd && env->me_mfd != INVALID_HANDLE_VALUE) + close(env->me_mfd); + if (env->me_fd != INVALID_HANDLE_VALUE) + close(env->me_fd); + if (env->me_txns) { + pid_t pid = env->me_pid; + /* Clearing readers is done in this function because + * me_txkey with its destructor must be disabled first. + */ + for (i = env->me_numreaders; --i >= 0; ) + if (env->me_txns->mti_readers[i].mr_pid == pid) + env->me_txns->mti_readers[i].mr_pid = 0; +#ifdef _WIN32 + if (env->me_rmutex) { + CloseHandle(env->me_rmutex); + if (env->me_wmutex) CloseHandle(env->me_wmutex); + } + /* Windows automatically destroys the mutexes when + * the last handle closes. + */ +#elif defined(MDB_USE_POSIX_SEM) + if (env->me_rmutex != SEM_FAILED) { + sem_close(env->me_rmutex); + if (env->me_wmutex != SEM_FAILED) + sem_close(env->me_wmutex); + /* If we have the filelock: If we are the + * only remaining user, clean up semaphores. + */ + if (excl == 0) + mdb_env_excl_lock(env, &excl); + if (excl > 0) { + sem_unlink(env->me_txns->mti_rmname); + sem_unlink(env->me_txns->mti_wmname); + } + } +#endif + munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo)); + } + close(env->me_lfd); + + env->me_lfd = INVALID_HANDLE_VALUE; /* Mark env as reset */ +} + +void +mdb_env_close(MDB_env *env) +{ + MDB_page *dp; + + if (env == NULL) + return; + + VGMEMP_DESTROY(env); + while ((dp = env->me_dpages) != NULL) { + VGMEMP_DEFINED(&dp->mp_next, sizeof(dp->mp_next)); + env->me_dpages = dp->mp_next; + free(dp); + } + + mdb_env_close0(env, 0); + mdb_midl_free(env->me_free_pgs); + free(env); +} + +/** Compare two items pointing at aligned size_t's */ +static int +mdb_cmp_long(const MDB_val *a, const MDB_val *b) +{ + return (*(size_t *)a->mv_data < *(size_t *)b->mv_data) ? -1 : + *(size_t *)a->mv_data > *(size_t *)b->mv_data; +} + +/** Compare two items pointing at aligned int's */ +static int +mdb_cmp_int(const MDB_val *a, const MDB_val *b) +{ + return (*(unsigned int *)a->mv_data < *(unsigned int *)b->mv_data) ? -1 : + *(unsigned int *)a->mv_data > *(unsigned int *)b->mv_data; +} + +/** Compare two items pointing at ints of unknown alignment. + * Nodes and keys are guaranteed to be 2-byte aligned. + */ +static int +mdb_cmp_cint(const MDB_val *a, const MDB_val *b) +{ +#if BYTE_ORDER == LITTLE_ENDIAN + unsigned short *u, *c; + int x; + + u = (unsigned short *) ((char *) a->mv_data + a->mv_size); + c = (unsigned short *) ((char *) b->mv_data + a->mv_size); + do { + x = *--u - *--c; + } while(!x && u > (unsigned short *)a->mv_data); + return x; +#else + return memcmp(a->mv_data, b->mv_data, a->mv_size); +#endif +} + +/** Compare two items lexically */ +static int +mdb_cmp_memn(const MDB_val *a, const MDB_val *b) +{ + int diff; + ssize_t len_diff; + unsigned int len; + + len = a->mv_size; + len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size; + if (len_diff > 0) { + len = b->mv_size; + len_diff = 1; + } + + diff = memcmp(a->mv_data, b->mv_data, len); + return diff ? diff : len_diff<0 ? -1 : len_diff; +} + +/** Compare two items in reverse byte order */ +static int +mdb_cmp_memnr(const MDB_val *a, const MDB_val *b) +{ + const unsigned char *p1, *p2, *p1_lim; + ssize_t len_diff; + int diff; + + p1_lim = (const unsigned char *)a->mv_data; + p1 = (const unsigned char *)a->mv_data + a->mv_size; + p2 = (const unsigned char *)b->mv_data + b->mv_size; + + len_diff = (ssize_t) a->mv_size - (ssize_t) b->mv_size; + if (len_diff > 0) { + p1_lim += len_diff; + len_diff = 1; + } + + while (p1 > p1_lim) { + diff = *--p1 - *--p2; + if (diff) + return diff; + } + return len_diff<0 ? -1 : len_diff; +} + +/** Search for key within a page, using binary search. + * Returns the smallest entry larger or equal to the key. + * If exactp is non-null, stores whether the found entry was an exact match + * in *exactp (1 or 0). + * Updates the cursor index with the index of the found entry. + * If no entry larger or equal to the key is found, returns NULL. + */ +static MDB_node * +mdb_node_search(MDB_cursor *mc, MDB_val *key, int *exactp) +{ + unsigned int i = 0, nkeys; + int low, high; + int rc = 0; + MDB_page *mp = mc->mc_pg[mc->mc_top]; + MDB_node *node = NULL; + MDB_val nodekey; + MDB_cmp_func *cmp; + DKBUF; + + nkeys = NUMKEYS(mp); + +#if MDB_DEBUG + { + pgno_t pgno; + COPY_PGNO(pgno, mp->mp_pgno); + DPRINTF("searching %u keys in %s %spage %zu", + nkeys, IS_LEAF(mp) ? "leaf" : "branch", IS_SUBP(mp) ? "sub-" : "", + pgno); + } +#endif + + assert(nkeys > 0); + + low = IS_LEAF(mp) ? 0 : 1; + high = nkeys - 1; + cmp = mc->mc_dbx->md_cmp; + + /* Branch pages have no data, so if using integer keys, + * alignment is guaranteed. Use faster mdb_cmp_int. + */ + if (cmp == mdb_cmp_cint && IS_BRANCH(mp)) { + if (NODEPTR(mp, 1)->mn_ksize == sizeof(size_t)) + cmp = mdb_cmp_long; + else + cmp = mdb_cmp_int; + } + + if (IS_LEAF2(mp)) { + nodekey.mv_size = mc->mc_db->md_pad; + node = NODEPTR(mp, 0); /* fake */ + while (low <= high) { + i = (low + high) >> 1; + nodekey.mv_data = LEAF2KEY(mp, i, nodekey.mv_size); + rc = cmp(key, &nodekey); + DPRINTF("found leaf index %u [%s], rc = %i", + i, DKEY(&nodekey), rc); + if (rc == 0) + break; + if (rc > 0) + low = i + 1; + else + high = i - 1; + } + } else { + while (low <= high) { + i = (low + high) >> 1; + + node = NODEPTR(mp, i); + nodekey.mv_size = NODEKSZ(node); + nodekey.mv_data = NODEKEY(node); + + rc = cmp(key, &nodekey); +#if MDB_DEBUG + if (IS_LEAF(mp)) + DPRINTF("found leaf index %u [%s], rc = %i", + i, DKEY(&nodekey), rc); + else + DPRINTF("found branch index %u [%s -> %zu], rc = %i", + i, DKEY(&nodekey), NODEPGNO(node), rc); +#endif + if (rc == 0) + break; + if (rc > 0) + low = i + 1; + else + high = i - 1; + } + } + + if (rc > 0) { /* Found entry is less than the key. */ + i++; /* Skip to get the smallest entry larger than key. */ + if (!IS_LEAF2(mp)) + node = NODEPTR(mp, i); + } + if (exactp) + *exactp = (rc == 0); + /* store the key index */ + mc->mc_ki[mc->mc_top] = i; + if (i >= nkeys) + /* There is no entry larger or equal to the key. */ + return NULL; + + /* nodeptr is fake for LEAF2 */ + return node; +} + +#if 0 +static void +mdb_cursor_adjust(MDB_cursor *mc, func) +{ + MDB_cursor *m2; + + for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) { + if (m2->mc_pg[m2->mc_top] == mc->mc_pg[mc->mc_top]) { + func(mc, m2); + } + } +} +#endif + +/** Pop a page off the top of the cursor's stack. */ +static void +mdb_cursor_pop(MDB_cursor *mc) +{ + if (mc->mc_snum) { +#if MDB_DEBUG + MDB_page *top = mc->mc_pg[mc->mc_top]; +#endif + mc->mc_snum--; + if (mc->mc_snum) + mc->mc_top--; + + DPRINTF("popped page %zu off db %u cursor %p", top->mp_pgno, + mc->mc_dbi, (void *) mc); + } +} + +/** Push a page onto the top of the cursor's stack. */ +static int +mdb_cursor_push(MDB_cursor *mc, MDB_page *mp) +{ + DPRINTF("pushing page %zu on db %u cursor %p", mp->mp_pgno, + mc->mc_dbi, (void *) mc); + + if (mc->mc_snum >= CURSOR_STACK) { + assert(mc->mc_snum < CURSOR_STACK); + return MDB_CURSOR_FULL; + } + + mc->mc_top = mc->mc_snum++; + mc->mc_pg[mc->mc_top] = mp; + mc->mc_ki[mc->mc_top] = 0; + + return MDB_SUCCESS; +} + +/** Find the address of the page corresponding to a given page number. + * @param[in] txn the transaction for this access. + * @param[in] pgno the page number for the page to retrieve. + * @param[out] ret address of a pointer where the page's address will be stored. + * @return 0 on success, non-zero on failure. + */ +static int +mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret) +{ + MDB_page *p = NULL; + + if (txn->mt_env->me_flags & MDB_WRITEMAP) { + if (pgno < txn->mt_next_pgno) + p = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno); + goto done; + } + if (!F_ISSET(txn->mt_flags, MDB_TXN_RDONLY) && txn->mt_u.dirty_list[0].mid) { + unsigned x; + x = mdb_mid2l_search(txn->mt_u.dirty_list, pgno); + if (x <= txn->mt_u.dirty_list[0].mid && txn->mt_u.dirty_list[x].mid == pgno) { + p = txn->mt_u.dirty_list[x].mptr; + } + } + if (!p) { + if (pgno < txn->mt_next_pgno) + p = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno); + } +done: + *ret = p; + if (!p) { + DPRINTF("page %zu not found", pgno); + assert(p != NULL); + } + return (p != NULL) ? MDB_SUCCESS : MDB_PAGE_NOTFOUND; +} + +/** Search for the page a given key should be in. + * Pushes parent pages on the cursor stack. This function continues a + * search on a cursor that has already been initialized. (Usually by + * #mdb_page_search() but also by #mdb_node_move().) + * @param[in,out] mc the cursor for this operation. + * @param[in] key the key to search for. If NULL, search for the lowest + * page. (This is used by #mdb_cursor_first().) + * @param[in] flags If MDB_PS_MODIFY set, visited pages are updated with new page numbers. + * If MDB_PS_ROOTONLY set, just fetch root node, no further lookups. + * @return 0 on success, non-zero on failure. + */ +static int +mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int modify) +{ + MDB_page *mp = mc->mc_pg[mc->mc_top]; + DKBUF; + int rc; + + + while (IS_BRANCH(mp)) { + MDB_node *node; + indx_t i; + + DPRINTF("branch page %zu has %u keys", mp->mp_pgno, NUMKEYS(mp)); + assert(NUMKEYS(mp) > 1); + DPRINTF("found index 0 to page %zu", NODEPGNO(NODEPTR(mp, 0))); + + if (key == NULL) /* Initialize cursor to first page. */ + i = 0; + else if (key->mv_size > MAXKEYSIZE && key->mv_data == NULL) { + /* cursor to last page */ + i = NUMKEYS(mp)-1; + } else { + int exact; + node = mdb_node_search(mc, key, &exact); + if (node == NULL) + i = NUMKEYS(mp) - 1; + else { + i = mc->mc_ki[mc->mc_top]; + if (!exact) { + assert(i > 0); + i--; + } + } + } + + if (key) + DPRINTF("following index %u for key [%s]", + i, DKEY(key)); + assert(i < NUMKEYS(mp)); + node = NODEPTR(mp, i); + + if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp))) + return rc; + + mc->mc_ki[mc->mc_top] = i; + if ((rc = mdb_cursor_push(mc, mp))) + return rc; + + if (modify) { + if ((rc = mdb_page_touch(mc)) != 0) + return rc; + mp = mc->mc_pg[mc->mc_top]; + } + } + + if (!IS_LEAF(mp)) { + DPRINTF("internal error, index points to a %02X page!?", + mp->mp_flags); + return MDB_CORRUPTED; + } + + DPRINTF("found leaf page %zu for key [%s]", mp->mp_pgno, + key ? DKEY(key) : NULL); + + return MDB_SUCCESS; +} + +/** Search for the page a given key should be in. + * Pushes parent pages on the cursor stack. This function just sets up + * the search; it finds the root page for \b mc's database and sets this + * as the root of the cursor's stack. Then #mdb_page_search_root() is + * called to complete the search. + * @param[in,out] mc the cursor for this operation. + * @param[in] key the key to search for. If NULL, search for the lowest + * page. (This is used by #mdb_cursor_first().) + * @param[in] modify If true, visited pages are updated with new page numbers. + * @return 0 on success, non-zero on failure. + */ +static int +mdb_page_search(MDB_cursor *mc, MDB_val *key, int flags) +{ + int rc; + pgno_t root; + + /* Make sure the txn is still viable, then find the root from + * the txn's db table. + */ + if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_ERROR)) { + DPUTS("transaction has failed, must abort"); + return EINVAL; + } else { + /* Make sure we're using an up-to-date root */ + if (mc->mc_dbi > MAIN_DBI) { + if ((*mc->mc_dbflag & DB_STALE) || + ((flags & MDB_PS_MODIFY) && !(*mc->mc_dbflag & DB_DIRTY))) { + MDB_cursor mc2; + unsigned char dbflag = 0; + mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL); + rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, flags & MDB_PS_MODIFY); + if (rc) + return rc; + if (*mc->mc_dbflag & DB_STALE) { + MDB_val data; + int exact = 0; + MDB_node *leaf = mdb_node_search(&mc2, + &mc->mc_dbx->md_name, &exact); + if (!exact) + return MDB_NOTFOUND; + mdb_node_read(mc->mc_txn, leaf, &data); + memcpy(mc->mc_db, data.mv_data, sizeof(MDB_db)); + } + if (flags & MDB_PS_MODIFY) + dbflag = DB_DIRTY; + *mc->mc_dbflag = dbflag; + } + } + root = mc->mc_db->md_root; + + if (root == P_INVALID) { /* Tree is empty. */ + DPUTS("tree is empty"); + return MDB_NOTFOUND; + } + } + + assert(root > 1); + if (!mc->mc_pg[0] || mc->mc_pg[0]->mp_pgno != root) + if ((rc = mdb_page_get(mc->mc_txn, root, &mc->mc_pg[0]))) + return rc; + + mc->mc_snum = 1; + mc->mc_top = 0; + + DPRINTF("db %u root page %zu has flags 0x%X", + mc->mc_dbi, root, mc->mc_pg[0]->mp_flags); + + if (flags & MDB_PS_MODIFY) { + if ((rc = mdb_page_touch(mc))) + return rc; + } + + if (flags & MDB_PS_ROOTONLY) + return MDB_SUCCESS; + + return mdb_page_search_root(mc, key, flags); +} + +/** Return the data associated with a given node. + * @param[in] txn The transaction for this operation. + * @param[in] leaf The node being read. + * @param[out] data Updated to point to the node's data. + * @return 0 on success, non-zero on failure. + */ +static int +mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data) +{ + MDB_page *omp; /* overflow page */ + pgno_t pgno; + int rc; + + if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) { + data->mv_size = NODEDSZ(leaf); + data->mv_data = NODEDATA(leaf); + return MDB_SUCCESS; + } + + /* Read overflow data. + */ + data->mv_size = NODEDSZ(leaf); + memcpy(&pgno, NODEDATA(leaf), sizeof(pgno)); + if ((rc = mdb_page_get(txn, pgno, &omp))) { + DPRINTF("read overflow page %zu failed", pgno); + return rc; + } + data->mv_data = METADATA(omp); + + return MDB_SUCCESS; +} + +int +mdb_get(MDB_txn *txn, MDB_dbi dbi, + MDB_val *key, MDB_val *data) +{ + MDB_cursor mc; + MDB_xcursor mx; + int exact = 0; + DKBUF; + + assert(key); + assert(data); + DPRINTF("===> get db %u key [%s]", dbi, DKEY(key)); + + if (txn == NULL || !dbi || dbi >= txn->mt_numdbs) + return EINVAL; + + if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) { + return EINVAL; + } + + mdb_cursor_init(&mc, txn, dbi, &mx); + return mdb_cursor_set(&mc, key, data, MDB_SET, &exact); +} + +/** Find a sibling for a page. + * Replaces the page at the top of the cursor's stack with the + * specified sibling, if one exists. + * @param[in] mc The cursor for this operation. + * @param[in] move_right Non-zero if the right sibling is requested, + * otherwise the left sibling. + * @return 0 on success, non-zero on failure. + */ +static int +mdb_cursor_sibling(MDB_cursor *mc, int move_right) +{ + int rc; + MDB_node *indx; + MDB_page *mp; + + if (mc->mc_snum < 2) { + return MDB_NOTFOUND; /* root has no siblings */ + } + + mdb_cursor_pop(mc); + DPRINTF("parent page is page %zu, index %u", + mc->mc_pg[mc->mc_top]->mp_pgno, mc->mc_ki[mc->mc_top]); + + if (move_right ? (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mc->mc_pg[mc->mc_top])) + : (mc->mc_ki[mc->mc_top] == 0)) { + DPRINTF("no more keys left, moving to %s sibling", + move_right ? "right" : "left"); + if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) + return rc; + } else { + if (move_right) + mc->mc_ki[mc->mc_top]++; + else + mc->mc_ki[mc->mc_top]--; + DPRINTF("just moving to %s index key %u", + move_right ? "right" : "left", mc->mc_ki[mc->mc_top]); + } + assert(IS_BRANCH(mc->mc_pg[mc->mc_top])); + + indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); + if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp))) + return rc;; + + mdb_cursor_push(mc, mp); + + return MDB_SUCCESS; +} + +/** Move the cursor to the next data item. */ +static int +mdb_cursor_next(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op) +{ + MDB_page *mp; + MDB_node *leaf; + int rc; + + if (mc->mc_flags & C_EOF) { + return MDB_NOTFOUND; + } + + assert(mc->mc_flags & C_INITIALIZED); + + mp = mc->mc_pg[mc->mc_top]; + + if (mc->mc_db->md_flags & MDB_DUPSORT) { + leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); + if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { + if (op == MDB_NEXT || op == MDB_NEXT_DUP) { + rc = mdb_cursor_next(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_NEXT); + if (op != MDB_NEXT || rc == MDB_SUCCESS) + return rc; + } + } else { + mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED; + if (op == MDB_NEXT_DUP) + return MDB_NOTFOUND; + } + } + + DPRINTF("cursor_next: top page is %zu in cursor %p", mp->mp_pgno, (void *) mc); + + if (mc->mc_ki[mc->mc_top] + 1u >= NUMKEYS(mp)) { + DPUTS("=====> move to next sibling page"); + if (mdb_cursor_sibling(mc, 1) != MDB_SUCCESS) { + mc->mc_flags |= C_EOF; + mc->mc_flags &= ~C_INITIALIZED; + return MDB_NOTFOUND; + } + mp = mc->mc_pg[mc->mc_top]; + DPRINTF("next page is %zu, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]); + } else + mc->mc_ki[mc->mc_top]++; + + DPRINTF("==> cursor points to page %zu with %u keys, key index %u", + mp->mp_pgno, NUMKEYS(mp), mc->mc_ki[mc->mc_top]); + + if (IS_LEAF2(mp)) { + key->mv_size = mc->mc_db->md_pad; + key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size); + return MDB_SUCCESS; + } + + assert(IS_LEAF(mp)); + leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); + + if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { + mdb_xcursor_init1(mc, leaf); + } + if (data) { + if ((rc = mdb_node_read(mc->mc_txn, leaf, data) != MDB_SUCCESS)) + return rc; + + if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { + rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL); + if (rc != MDB_SUCCESS) + return rc; + } + } + + MDB_GET_KEY(leaf, key); + return MDB_SUCCESS; +} + +/** Move the cursor to the previous data item. */ +static int +mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op) +{ + MDB_page *mp; + MDB_node *leaf; + int rc; + + assert(mc->mc_flags & C_INITIALIZED); + + mp = mc->mc_pg[mc->mc_top]; + + if (mc->mc_db->md_flags & MDB_DUPSORT) { + leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); + if (op == MDB_PREV || op == MDB_PREV_DUP) { + if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { + rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV); + if (op != MDB_PREV || rc == MDB_SUCCESS) + return rc; + } else { + mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED; + if (op == MDB_PREV_DUP) + return MDB_NOTFOUND; + } + } + } + + DPRINTF("cursor_prev: top page is %zu in cursor %p", mp->mp_pgno, (void *) mc); + + if (mc->mc_ki[mc->mc_top] == 0) { + DPUTS("=====> move to prev sibling page"); + if (mdb_cursor_sibling(mc, 0) != MDB_SUCCESS) { + mc->mc_flags &= ~C_INITIALIZED; + return MDB_NOTFOUND; + } + mp = mc->mc_pg[mc->mc_top]; + mc->mc_ki[mc->mc_top] = NUMKEYS(mp) - 1; + DPRINTF("prev page is %zu, key index %u", mp->mp_pgno, mc->mc_ki[mc->mc_top]); + } else + mc->mc_ki[mc->mc_top]--; + + mc->mc_flags &= ~C_EOF; + + DPRINTF("==> cursor points to page %zu with %u keys, key index %u", + mp->mp_pgno, NUMKEYS(mp), mc->mc_ki[mc->mc_top]); + + if (IS_LEAF2(mp)) { + key->mv_size = mc->mc_db->md_pad; + key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size); + return MDB_SUCCESS; + } + + assert(IS_LEAF(mp)); + leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); + + if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { + mdb_xcursor_init1(mc, leaf); + } + if (data) { + if ((rc = mdb_node_read(mc->mc_txn, leaf, data) != MDB_SUCCESS)) + return rc; + + if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { + rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL); + if (rc != MDB_SUCCESS) + return rc; + } + } + + MDB_GET_KEY(leaf, key); + return MDB_SUCCESS; +} + +/** Set the cursor on a specific data item. */ +static int +mdb_cursor_set(MDB_cursor *mc, MDB_val *key, MDB_val *data, + MDB_cursor_op op, int *exactp) +{ + int rc; + MDB_page *mp; + MDB_node *leaf = NULL; + DKBUF; + + assert(mc); + assert(key); + assert(key->mv_size > 0); + + /* See if we're already on the right page */ + if (mc->mc_flags & C_INITIALIZED) { + MDB_val nodekey; + + mp = mc->mc_pg[mc->mc_top]; + if (!NUMKEYS(mp)) { + mc->mc_ki[mc->mc_top] = 0; + return MDB_NOTFOUND; + } + if (mp->mp_flags & P_LEAF2) { + nodekey.mv_size = mc->mc_db->md_pad; + nodekey.mv_data = LEAF2KEY(mp, 0, nodekey.mv_size); + } else { + leaf = NODEPTR(mp, 0); + MDB_GET_KEY(leaf, &nodekey); + } + rc = mc->mc_dbx->md_cmp(key, &nodekey); + if (rc == 0) { + /* Probably happens rarely, but first node on the page + * was the one we wanted. + */ + mc->mc_ki[mc->mc_top] = 0; + if (exactp) + *exactp = 1; + goto set1; + } + if (rc > 0) { + unsigned int i; + unsigned int nkeys = NUMKEYS(mp); + if (nkeys > 1) { + if (mp->mp_flags & P_LEAF2) { + nodekey.mv_data = LEAF2KEY(mp, + nkeys-1, nodekey.mv_size); + } else { + leaf = NODEPTR(mp, nkeys-1); + MDB_GET_KEY(leaf, &nodekey); + } + rc = mc->mc_dbx->md_cmp(key, &nodekey); + if (rc == 0) { + /* last node was the one we wanted */ + mc->mc_ki[mc->mc_top] = nkeys-1; + if (exactp) + *exactp = 1; + goto set1; + } + if (rc < 0) { + if (mc->mc_ki[mc->mc_top] < NUMKEYS(mp)) { + /* This is definitely the right page, skip search_page */ + if (mp->mp_flags & P_LEAF2) { + nodekey.mv_data = LEAF2KEY(mp, + mc->mc_ki[mc->mc_top], nodekey.mv_size); + } else { + leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); + MDB_GET_KEY(leaf, &nodekey); + } + rc = mc->mc_dbx->md_cmp(key, &nodekey); + if (rc == 0) { + /* current node was the one we wanted */ + if (exactp) + *exactp = 1; + goto set1; + } + } + rc = 0; + goto set2; + } + } + /* If any parents have right-sibs, search. + * Otherwise, there's nothing further. + */ + for (i=0; imc_top; i++) + if (mc->mc_ki[i] < + NUMKEYS(mc->mc_pg[i])-1) + break; + if (i == mc->mc_top) { + /* There are no other pages */ + mc->mc_ki[mc->mc_top] = nkeys; + return MDB_NOTFOUND; + } + } + if (!mc->mc_top) { + /* There are no other pages */ + mc->mc_ki[mc->mc_top] = 0; + return MDB_NOTFOUND; + } + } + + rc = mdb_page_search(mc, key, 0); + if (rc != MDB_SUCCESS) + return rc; + + mp = mc->mc_pg[mc->mc_top]; + assert(IS_LEAF(mp)); + +set2: + leaf = mdb_node_search(mc, key, exactp); + if (exactp != NULL && !*exactp) { + /* MDB_SET specified and not an exact match. */ + return MDB_NOTFOUND; + } + + if (leaf == NULL) { + DPUTS("===> inexact leaf not found, goto sibling"); + if ((rc = mdb_cursor_sibling(mc, 1)) != MDB_SUCCESS) + return rc; /* no entries matched */ + mp = mc->mc_pg[mc->mc_top]; + assert(IS_LEAF(mp)); + leaf = NODEPTR(mp, 0); + } + +set1: + mc->mc_flags |= C_INITIALIZED; + mc->mc_flags &= ~C_EOF; + + if (IS_LEAF2(mp)) { + key->mv_size = mc->mc_db->md_pad; + key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size); + return MDB_SUCCESS; + } + + if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { + mdb_xcursor_init1(mc, leaf); + } + if (data) { + if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { + if (op == MDB_SET || op == MDB_SET_KEY || op == MDB_SET_RANGE) { + rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL); + } else { + int ex2, *ex2p; + if (op == MDB_GET_BOTH) { + ex2p = &ex2; + ex2 = 0; + } else { + ex2p = NULL; + } + rc = mdb_cursor_set(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_SET_RANGE, ex2p); + if (rc != MDB_SUCCESS) + return rc; + } + } else if (op == MDB_GET_BOTH || op == MDB_GET_BOTH_RANGE) { + MDB_val d2; + if ((rc = mdb_node_read(mc->mc_txn, leaf, &d2)) != MDB_SUCCESS) + return rc; + rc = mc->mc_dbx->md_dcmp(data, &d2); + if (rc) { + if (op == MDB_GET_BOTH || rc > 0) + return MDB_NOTFOUND; + } + + } else { + if (mc->mc_xcursor) + mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED; + if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS) + return rc; + } + } + + /* The key already matches in all other cases */ + if (op == MDB_SET_RANGE || op == MDB_SET_KEY) + MDB_GET_KEY(leaf, key); + DPRINTF("==> cursor placed on key [%s]", DKEY(key)); + + return rc; +} + +/** Move the cursor to the first item in the database. */ +static int +mdb_cursor_first(MDB_cursor *mc, MDB_val *key, MDB_val *data) +{ + int rc; + MDB_node *leaf; + + if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) { + rc = mdb_page_search(mc, NULL, 0); + if (rc != MDB_SUCCESS) + return rc; + } + assert(IS_LEAF(mc->mc_pg[mc->mc_top])); + + leaf = NODEPTR(mc->mc_pg[mc->mc_top], 0); + mc->mc_flags |= C_INITIALIZED; + mc->mc_flags &= ~C_EOF; + + mc->mc_ki[mc->mc_top] = 0; + + if (IS_LEAF2(mc->mc_pg[mc->mc_top])) { + key->mv_size = mc->mc_db->md_pad; + key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], 0, key->mv_size); + return MDB_SUCCESS; + } + + if (data) { + if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { + mdb_xcursor_init1(mc, leaf); + rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL); + if (rc) + return rc; + } else { + if (mc->mc_xcursor) + mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED; + if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS) + return rc; + } + } + MDB_GET_KEY(leaf, key); + return MDB_SUCCESS; +} + +/** Move the cursor to the last item in the database. */ +static int +mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data) +{ + int rc; + MDB_node *leaf; + + if (!(mc->mc_flags & C_EOF)) { + + if (!(mc->mc_flags & C_INITIALIZED) || mc->mc_top) { + MDB_val lkey; + + lkey.mv_size = MAXKEYSIZE+1; + lkey.mv_data = NULL; + rc = mdb_page_search(mc, &lkey, 0); + if (rc != MDB_SUCCESS) + return rc; + } + assert(IS_LEAF(mc->mc_pg[mc->mc_top])); + + mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1; + mc->mc_flags |= C_INITIALIZED|C_EOF; + } + leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); + + if (IS_LEAF2(mc->mc_pg[mc->mc_top])) { + key->mv_size = mc->mc_db->md_pad; + key->mv_data = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], key->mv_size); + return MDB_SUCCESS; + } + + if (data) { + if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { + mdb_xcursor_init1(mc, leaf); + rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL); + if (rc) + return rc; + } else { + if (mc->mc_xcursor) + mc->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED; + if ((rc = mdb_node_read(mc->mc_txn, leaf, data)) != MDB_SUCCESS) + return rc; + } + } + + MDB_GET_KEY(leaf, key); + return MDB_SUCCESS; +} + +int +mdb_cursor_get(MDB_cursor *mc, MDB_val *key, MDB_val *data, + MDB_cursor_op op) +{ + int rc; + int exact = 0; + + assert(mc); + + switch (op) { + case MDB_GET_CURRENT: + if (!mc->mc_flags & C_INITIALIZED) { + rc = EINVAL; + } else { + MDB_page *mp = mc->mc_pg[mc->mc_top]; + if (!NUMKEYS(mp)) { + mc->mc_ki[mc->mc_top] = 0; + rc = MDB_NOTFOUND; + break; + } + rc = MDB_SUCCESS; + if (IS_LEAF2(mp)) { + key->mv_size = mc->mc_db->md_pad; + key->mv_data = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], key->mv_size); + } else { + MDB_node *leaf = NODEPTR(mp, mc->mc_ki[mc->mc_top]); + MDB_GET_KEY(leaf, key); + if (data) { + if (F_ISSET(leaf->mn_flags, F_DUPDATA)) { + rc = mdb_cursor_get(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_GET_CURRENT); + } else { + rc = mdb_node_read(mc->mc_txn, leaf, data); + } + } + } + } + break; + case MDB_GET_BOTH: + case MDB_GET_BOTH_RANGE: + if (data == NULL || mc->mc_xcursor == NULL) { + rc = EINVAL; + break; + } + /* FALLTHRU */ + case MDB_SET: + case MDB_SET_KEY: + case MDB_SET_RANGE: + if (key == NULL || key->mv_size == 0 || key->mv_size > MAXKEYSIZE) { + rc = EINVAL; + } else if (op == MDB_SET_RANGE) + rc = mdb_cursor_set(mc, key, data, op, NULL); + else + rc = mdb_cursor_set(mc, key, data, op, &exact); + break; + case MDB_GET_MULTIPLE: + if (data == NULL || + !(mc->mc_db->md_flags & MDB_DUPFIXED) || + !(mc->mc_flags & C_INITIALIZED)) { + rc = EINVAL; + break; + } + rc = MDB_SUCCESS; + if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) || + (mc->mc_xcursor->mx_cursor.mc_flags & C_EOF)) + break; + goto fetchm; + case MDB_NEXT_MULTIPLE: + if (data == NULL || + !(mc->mc_db->md_flags & MDB_DUPFIXED)) { + rc = EINVAL; + break; + } + if (!(mc->mc_flags & C_INITIALIZED)) + rc = mdb_cursor_first(mc, key, data); + else + rc = mdb_cursor_next(mc, key, data, MDB_NEXT_DUP); + if (rc == MDB_SUCCESS) { + if (mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED) { + MDB_cursor *mx; +fetchm: + mx = &mc->mc_xcursor->mx_cursor; + data->mv_size = NUMKEYS(mx->mc_pg[mx->mc_top]) * + mx->mc_db->md_pad; + data->mv_data = METADATA(mx->mc_pg[mx->mc_top]); + mx->mc_ki[mx->mc_top] = NUMKEYS(mx->mc_pg[mx->mc_top])-1; + } else { + rc = MDB_NOTFOUND; + } + } + break; + case MDB_NEXT: + case MDB_NEXT_DUP: + case MDB_NEXT_NODUP: + if (!(mc->mc_flags & C_INITIALIZED)) + rc = mdb_cursor_first(mc, key, data); + else + rc = mdb_cursor_next(mc, key, data, op); + break; + case MDB_PREV: + case MDB_PREV_DUP: + case MDB_PREV_NODUP: + if (!(mc->mc_flags & C_INITIALIZED) || (mc->mc_flags & C_EOF)) { + rc = mdb_cursor_last(mc, key, data); + mc->mc_flags &= ~C_EOF; + } else + rc = mdb_cursor_prev(mc, key, data, op); + break; + case MDB_FIRST: + rc = mdb_cursor_first(mc, key, data); + break; + case MDB_FIRST_DUP: + if (data == NULL || + !(mc->mc_db->md_flags & MDB_DUPSORT) || + !(mc->mc_flags & C_INITIALIZED) || + !(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) { + rc = EINVAL; + break; + } + rc = mdb_cursor_first(&mc->mc_xcursor->mx_cursor, data, NULL); + break; + case MDB_LAST: + rc = mdb_cursor_last(mc, key, data); + break; + case MDB_LAST_DUP: + if (data == NULL || + !(mc->mc_db->md_flags & MDB_DUPSORT) || + !(mc->mc_flags & C_INITIALIZED) || + !(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) { + rc = EINVAL; + break; + } + rc = mdb_cursor_last(&mc->mc_xcursor->mx_cursor, data, NULL); + break; + default: + DPRINTF("unhandled/unimplemented cursor operation %u", op); + rc = EINVAL; + break; + } + + return rc; +} + +/** Touch all the pages in the cursor stack. + * Makes sure all the pages are writable, before attempting a write operation. + * @param[in] mc The cursor to operate on. + */ +static int +mdb_cursor_touch(MDB_cursor *mc) +{ + int rc; + + if (mc->mc_dbi > MAIN_DBI && !(*mc->mc_dbflag & DB_DIRTY)) { + MDB_cursor mc2; + mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL); + rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY); + if (rc) + return rc; + *mc->mc_dbflag = DB_DIRTY; + } + for (mc->mc_top = 0; mc->mc_top < mc->mc_snum; mc->mc_top++) { + rc = mdb_page_touch(mc); + if (rc) + return rc; + } + mc->mc_top = mc->mc_snum-1; + return MDB_SUCCESS; +} + +int +mdb_cursor_put(MDB_cursor *mc, MDB_val *key, MDB_val *data, + unsigned int flags) +{ + MDB_node *leaf = NULL; + MDB_val xdata, *rdata, dkey; + MDB_page *fp; + MDB_db dummy; + int do_sub = 0, insert = 0; + unsigned int mcount = 0; + size_t nsize; + int rc, rc2; + MDB_pagebuf pbuf; + char dbuf[MAXKEYSIZE+1]; + unsigned int nflags; + DKBUF; + + if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_RDONLY)) + return EACCES; + + DPRINTF("==> put db %u key [%s], size %zu, data size %zu", + mc->mc_dbi, DKEY(key), key ? key->mv_size:0, data->mv_size); + + dkey.mv_size = 0; + + if (flags == MDB_CURRENT) { + if (!(mc->mc_flags & C_INITIALIZED)) + return EINVAL; + rc = MDB_SUCCESS; + } else if (mc->mc_db->md_root == P_INVALID) { + MDB_page *np; + /* new database, write a root leaf page */ + DPUTS("allocating new root leaf page"); + if ((rc = mdb_page_new(mc, P_LEAF, 1, &np))) { + return rc; + } + mc->mc_snum = 0; + mdb_cursor_push(mc, np); + mc->mc_db->md_root = np->mp_pgno; + mc->mc_db->md_depth++; + *mc->mc_dbflag = DB_DIRTY; + if ((mc->mc_db->md_flags & (MDB_DUPSORT|MDB_DUPFIXED)) + == MDB_DUPFIXED) + np->mp_flags |= P_LEAF2; + mc->mc_flags |= C_INITIALIZED; + rc = MDB_NOTFOUND; + goto top; + } else { + int exact = 0; + MDB_val d2; + if (flags & MDB_APPEND) { + MDB_val k2; + rc = mdb_cursor_last(mc, &k2, &d2); + if (rc == 0) { + rc = mc->mc_dbx->md_cmp(key, &k2); + if (rc > 0) { + rc = MDB_NOTFOUND; + mc->mc_ki[mc->mc_top]++; + } else { + rc = 0; + } + } + } else { + rc = mdb_cursor_set(mc, key, &d2, MDB_SET, &exact); + } + if ((flags & MDB_NOOVERWRITE) && rc == 0) { + DPRINTF("duplicate key [%s]", DKEY(key)); + *data = d2; + return MDB_KEYEXIST; + } + if (rc && rc != MDB_NOTFOUND) + return rc; + } + + /* Cursor is positioned, now make sure all pages are writable */ + rc2 = mdb_cursor_touch(mc); + if (rc2) + return rc2; + +top: + /* The key already exists */ + if (rc == MDB_SUCCESS) { + /* there's only a key anyway, so this is a no-op */ + if (IS_LEAF2(mc->mc_pg[mc->mc_top])) { + unsigned int ksize = mc->mc_db->md_pad; + if (key->mv_size != ksize) + return EINVAL; + if (flags == MDB_CURRENT) { + char *ptr = LEAF2KEY(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], ksize); + memcpy(ptr, key->mv_data, ksize); + } + return MDB_SUCCESS; + } + + leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); + + /* DB has dups? */ + if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) { + /* Was a single item before, must convert now */ +more: + if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) { + /* Just overwrite the current item */ + if (flags == MDB_CURRENT) + goto current; + + dkey.mv_size = NODEDSZ(leaf); + dkey.mv_data = NODEDATA(leaf); +#if UINT_MAX < SIZE_MAX + if (mc->mc_dbx->md_dcmp == mdb_cmp_int && dkey.mv_size == sizeof(size_t)) +#ifdef MISALIGNED_OK + mc->mc_dbx->md_dcmp = mdb_cmp_long; +#else + mc->mc_dbx->md_dcmp = mdb_cmp_cint; +#endif +#endif + /* if data matches, ignore it */ + if (!mc->mc_dbx->md_dcmp(data, &dkey)) + return (flags == MDB_NODUPDATA) ? MDB_KEYEXIST : MDB_SUCCESS; + + /* create a fake page for the dup items */ + memcpy(dbuf, dkey.mv_data, dkey.mv_size); + dkey.mv_data = dbuf; + fp = (MDB_page *)&pbuf; + fp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno; + fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP; + fp->mp_lower = PAGEHDRSZ; + fp->mp_upper = PAGEHDRSZ + dkey.mv_size + data->mv_size; + if (mc->mc_db->md_flags & MDB_DUPFIXED) { + fp->mp_flags |= P_LEAF2; + fp->mp_pad = data->mv_size; + fp->mp_upper += 2 * data->mv_size; /* leave space for 2 more */ + } else { + fp->mp_upper += 2 * sizeof(indx_t) + 2 * NODESIZE + + (dkey.mv_size & 1) + (data->mv_size & 1); + } + mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0); + do_sub = 1; + rdata = &xdata; + xdata.mv_size = fp->mp_upper; + xdata.mv_data = fp; + flags |= F_DUPDATA; + goto new_sub; + } + if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) { + /* See if we need to convert from fake page to subDB */ + MDB_page *mp; + unsigned int offset; + unsigned int i; + + fp = NODEDATA(leaf); + if (flags == MDB_CURRENT) { +reuse: + fp->mp_flags |= P_DIRTY; + COPY_PGNO(fp->mp_pgno, mc->mc_pg[mc->mc_top]->mp_pgno); + mc->mc_xcursor->mx_cursor.mc_pg[0] = fp; + flags |= F_DUPDATA; + goto put_sub; + } + if (mc->mc_db->md_flags & MDB_DUPFIXED) { + offset = fp->mp_pad; + if (SIZELEFT(fp) >= offset) + goto reuse; + offset *= 4; /* space for 4 more */ + } else { + offset = NODESIZE + sizeof(indx_t) + data->mv_size; + } + offset += offset & 1; + if (NODESIZE + sizeof(indx_t) + NODEKSZ(leaf) + NODEDSZ(leaf) + + offset >= (mc->mc_txn->mt_env->me_psize - PAGEHDRSZ) / + MDB_MINKEYS) { + /* yes, convert it */ + dummy.md_flags = 0; + if (mc->mc_db->md_flags & MDB_DUPFIXED) { + dummy.md_pad = fp->mp_pad; + dummy.md_flags = MDB_DUPFIXED; + if (mc->mc_db->md_flags & MDB_INTEGERDUP) + dummy.md_flags |= MDB_INTEGERKEY; + } + dummy.md_depth = 1; + dummy.md_branch_pages = 0; + dummy.md_leaf_pages = 1; + dummy.md_overflow_pages = 0; + dummy.md_entries = NUMKEYS(fp); + rdata = &xdata; + xdata.mv_size = sizeof(MDB_db); + xdata.mv_data = &dummy; + if ((rc = mdb_page_alloc(mc, 1, &mp))) + return rc; + offset = mc->mc_txn->mt_env->me_psize - NODEDSZ(leaf); + flags |= F_DUPDATA|F_SUBDATA; + dummy.md_root = mp->mp_pgno; + } else { + /* no, just grow it */ + rdata = &xdata; + xdata.mv_size = NODEDSZ(leaf) + offset; + xdata.mv_data = &pbuf; + mp = (MDB_page *)&pbuf; + mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno; + flags |= F_DUPDATA; + } + mp->mp_flags = fp->mp_flags | P_DIRTY; + mp->mp_pad = fp->mp_pad; + mp->mp_lower = fp->mp_lower; + mp->mp_upper = fp->mp_upper + offset; + if (IS_LEAF2(fp)) { + memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad); + } else { + nsize = NODEDSZ(leaf) - fp->mp_upper; + memcpy((char *)mp + mp->mp_upper, (char *)fp + fp->mp_upper, nsize); + for (i=0; imp_ptrs[i] = fp->mp_ptrs[i] + offset; + } + mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0); + do_sub = 1; + goto new_sub; + } + /* data is on sub-DB, just store it */ + flags |= F_DUPDATA|F_SUBDATA; + goto put_sub; + } +current: + /* overflow page overwrites need special handling */ + if (F_ISSET(leaf->mn_flags, F_BIGDATA)) { + MDB_page *omp; + pgno_t pg; + int ovpages, dpages; + + ovpages = OVPAGES(NODEDSZ(leaf), mc->mc_txn->mt_env->me_psize); + dpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize); + memcpy(&pg, NODEDATA(leaf), sizeof(pg)); + mdb_page_get(mc->mc_txn, pg, &omp); + /* Is the ov page writable and large enough? */ + if ((omp->mp_flags & P_DIRTY) && ovpages >= dpages) { + /* yes, overwrite it. Note in this case we don't + * bother to try shrinking the node if the new data + * is smaller than the overflow threshold. + */ + if (F_ISSET(flags, MDB_RESERVE)) + data->mv_data = METADATA(omp); + else + memcpy(METADATA(omp), data->mv_data, data->mv_size); + goto done; + } else { + /* no, free ovpages */ + int i; + mc->mc_db->md_overflow_pages -= ovpages; + for (i=0; imc_txn->mt_free_pgs, pg); + pg++; + } + } + } else if (NODEDSZ(leaf) == data->mv_size) { + /* same size, just replace it. Note that we could + * also reuse this node if the new data is smaller, + * but instead we opt to shrink the node in that case. + */ + if (F_ISSET(flags, MDB_RESERVE)) + data->mv_data = NODEDATA(leaf); + else + memcpy(NODEDATA(leaf), data->mv_data, data->mv_size); + goto done; + } + mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], 0); + mc->mc_db->md_entries--; + } else { + DPRINTF("inserting key at index %i", mc->mc_ki[mc->mc_top]); + insert = 1; + } + + rdata = data; + +new_sub: + nflags = flags & NODE_ADD_FLAGS; + nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(mc->mc_txn->mt_env, key, rdata); + if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) { + if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA ) + nflags &= ~MDB_APPEND; + if (!insert) + nflags |= MDB_SPLIT_REPLACE; + rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags); + } else { + /* There is room already in this leaf page. */ + rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags); + if (rc == 0 && !do_sub && insert) { + /* Adjust other cursors pointing to mp */ + MDB_cursor *m2, *m3; + MDB_dbi dbi = mc->mc_dbi; + unsigned i = mc->mc_top; + MDB_page *mp = mc->mc_pg[i]; + + if (mc->mc_flags & C_SUB) + dbi--; + + for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { + if (mc->mc_flags & C_SUB) + m3 = &m2->mc_xcursor->mx_cursor; + else + m3 = m2; + if (m3 == mc || m3->mc_snum < mc->mc_snum) continue; + if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) { + m3->mc_ki[i]++; + } + } + } + } + + if (rc != MDB_SUCCESS) + mc->mc_txn->mt_flags |= MDB_TXN_ERROR; + else { + /* Now store the actual data in the child DB. Note that we're + * storing the user data in the keys field, so there are strict + * size limits on dupdata. The actual data fields of the child + * DB are all zero size. + */ + if (do_sub) { + int xflags; +put_sub: + xdata.mv_size = 0; + xdata.mv_data = ""; + leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); + if (flags & MDB_CURRENT) { + xflags = MDB_CURRENT; + } else { + mdb_xcursor_init1(mc, leaf); + xflags = (flags & MDB_NODUPDATA) ? MDB_NOOVERWRITE : 0; + } + /* converted, write the original data first */ + if (dkey.mv_size) { + rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags); + if (rc) + return rc; + { + /* Adjust other cursors pointing to mp */ + MDB_cursor *m2; + unsigned i = mc->mc_top; + MDB_page *mp = mc->mc_pg[i]; + + for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) { + if (m2 == mc || m2->mc_snum < mc->mc_snum) continue; + if (m2->mc_pg[i] == mp && m2->mc_ki[i] == mc->mc_ki[i]) { + mdb_xcursor_init1(m2, leaf); + } + } + } + } + if (flags & MDB_APPENDDUP) + xflags |= MDB_APPEND; + rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags); + if (flags & F_SUBDATA) { + void *db = NODEDATA(leaf); + memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db)); + } + } + /* sub-writes might have failed so check rc again. + * Don't increment count if we just replaced an existing item. + */ + if (!rc && !(flags & MDB_CURRENT)) + mc->mc_db->md_entries++; + if (flags & MDB_MULTIPLE) { + mcount++; + if (mcount < data[1].mv_size) { + data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size; + leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); + goto more; + } + } + } +done: + return rc; +} + +int +mdb_cursor_del(MDB_cursor *mc, unsigned int flags) +{ + MDB_node *leaf; + int rc; + + if (F_ISSET(mc->mc_txn->mt_flags, MDB_TXN_RDONLY)) + return EACCES; + + if (!mc->mc_flags & C_INITIALIZED) + return EINVAL; + + rc = mdb_cursor_touch(mc); + if (rc) + return rc; + + leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); + + if (!IS_LEAF2(mc->mc_pg[mc->mc_top]) && F_ISSET(leaf->mn_flags, F_DUPDATA)) { + if (flags != MDB_NODUPDATA) { + if (!F_ISSET(leaf->mn_flags, F_SUBDATA)) { + mc->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(leaf); + } + rc = mdb_cursor_del(&mc->mc_xcursor->mx_cursor, 0); + /* If sub-DB still has entries, we're done */ + if (mc->mc_xcursor->mx_db.md_entries) { + if (leaf->mn_flags & F_SUBDATA) { + /* update subDB info */ + void *db = NODEDATA(leaf); + memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db)); + } else { + /* shrink fake page */ + mdb_node_shrink(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); + } + mc->mc_db->md_entries--; + return rc; + } + /* otherwise fall thru and delete the sub-DB */ + } + + if (leaf->mn_flags & F_SUBDATA) { + /* add all the child DB's pages to the free list */ + rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0); + if (rc == MDB_SUCCESS) { + mc->mc_db->md_entries -= + mc->mc_xcursor->mx_db.md_entries; + } + } + } + + return mdb_cursor_del0(mc, leaf); +} + +/** Allocate and initialize new pages for a database. + * @param[in] mc a cursor on the database being added to. + * @param[in] flags flags defining what type of page is being allocated. + * @param[in] num the number of pages to allocate. This is usually 1, + * unless allocating overflow pages for a large record. + * @param[out] mp Address of a page, or NULL on failure. + * @return 0 on success, non-zero on failure. + */ +static int +mdb_page_new(MDB_cursor *mc, uint32_t flags, int num, MDB_page **mp) +{ + MDB_page *np; + int rc; + + if ((rc = mdb_page_alloc(mc, num, &np))) + return rc; + DPRINTF("allocated new mpage %zu, page size %u", + np->mp_pgno, mc->mc_txn->mt_env->me_psize); + np->mp_flags = flags | P_DIRTY; + np->mp_lower = PAGEHDRSZ; + np->mp_upper = mc->mc_txn->mt_env->me_psize; + + if (IS_BRANCH(np)) + mc->mc_db->md_branch_pages++; + else if (IS_LEAF(np)) + mc->mc_db->md_leaf_pages++; + else if (IS_OVERFLOW(np)) { + mc->mc_db->md_overflow_pages += num; + np->mp_pages = num; + } + *mp = np; + + return 0; +} + +/** Calculate the size of a leaf node. + * The size depends on the environment's page size; if a data item + * is too large it will be put onto an overflow page and the node + * size will only include the key and not the data. Sizes are always + * rounded up to an even number of bytes, to guarantee 2-byte alignment + * of the #MDB_node headers. + * @param[in] env The environment handle. + * @param[in] key The key for the node. + * @param[in] data The data for the node. + * @return The number of bytes needed to store the node. + */ +static size_t +mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data) +{ + size_t sz; + + sz = LEAFSIZE(key, data); + if (sz >= env->me_psize / MDB_MINKEYS) { + /* put on overflow page */ + sz -= data->mv_size - sizeof(pgno_t); + } + sz += sz & 1; + + return sz + sizeof(indx_t); +} + +/** Calculate the size of a branch node. + * The size should depend on the environment's page size but since + * we currently don't support spilling large keys onto overflow + * pages, it's simply the size of the #MDB_node header plus the + * size of the key. Sizes are always rounded up to an even number + * of bytes, to guarantee 2-byte alignment of the #MDB_node headers. + * @param[in] env The environment handle. + * @param[in] key The key for the node. + * @return The number of bytes needed to store the node. + */ +static size_t +mdb_branch_size(MDB_env *env, MDB_val *key) +{ + size_t sz; + + sz = INDXSIZE(key); + if (sz >= env->me_psize / MDB_MINKEYS) { + /* put on overflow page */ + /* not implemented */ + /* sz -= key->size - sizeof(pgno_t); */ + } + + return sz + sizeof(indx_t); +} + +/** Add a node to the page pointed to by the cursor. + * @param[in] mc The cursor for this operation. + * @param[in] indx The index on the page where the new node should be added. + * @param[in] key The key for the new node. + * @param[in] data The data for the new node, if any. + * @param[in] pgno The page number, if adding a branch node. + * @param[in] flags Flags for the node. + * @return 0 on success, non-zero on failure. Possible errors are: + *
    + *
  • ENOMEM - failed to allocate overflow pages for the node. + *
  • MDB_PAGE_FULL - there is insufficient room in the page. This error + * should never happen since all callers already calculate the + * page's free space before calling this function. + *
+ */ +static int +mdb_node_add(MDB_cursor *mc, indx_t indx, + MDB_val *key, MDB_val *data, pgno_t pgno, unsigned int flags) +{ + unsigned int i; + size_t node_size = NODESIZE; + indx_t ofs; + MDB_node *node; + MDB_page *mp = mc->mc_pg[mc->mc_top]; + MDB_page *ofp = NULL; /* overflow page */ + DKBUF; + + assert(mp->mp_upper >= mp->mp_lower); + + DPRINTF("add to %s %spage %zu index %i, data size %zu key size %zu [%s]", + IS_LEAF(mp) ? "leaf" : "branch", + IS_SUBP(mp) ? "sub-" : "", + mp->mp_pgno, indx, data ? data->mv_size : 0, + key ? key->mv_size : 0, key ? DKEY(key) : NULL); + + if (IS_LEAF2(mp)) { + /* Move higher keys up one slot. */ + int ksize = mc->mc_db->md_pad, dif; + char *ptr = LEAF2KEY(mp, indx, ksize); + dif = NUMKEYS(mp) - indx; + if (dif > 0) + memmove(ptr+ksize, ptr, dif*ksize); + /* insert new key */ + memcpy(ptr, key->mv_data, ksize); + + /* Just using these for counting */ + mp->mp_lower += sizeof(indx_t); + mp->mp_upper -= ksize - sizeof(indx_t); + return MDB_SUCCESS; + } + + if (key != NULL) + node_size += key->mv_size; + + if (IS_LEAF(mp)) { + assert(data); + if (F_ISSET(flags, F_BIGDATA)) { + /* Data already on overflow page. */ + node_size += sizeof(pgno_t); + } else if (node_size + data->mv_size >= mc->mc_txn->mt_env->me_psize / MDB_MINKEYS) { + int ovpages = OVPAGES(data->mv_size, mc->mc_txn->mt_env->me_psize); + int rc; + /* Put data on overflow page. */ + DPRINTF("data size is %zu, node would be %zu, put data on overflow page", + data->mv_size, node_size+data->mv_size); + node_size += sizeof(pgno_t); + if ((rc = mdb_page_new(mc, P_OVERFLOW, ovpages, &ofp))) + return rc; + DPRINTF("allocated overflow page %zu", ofp->mp_pgno); + flags |= F_BIGDATA; + } else { + node_size += data->mv_size; + } + } + node_size += node_size & 1; + + if (node_size + sizeof(indx_t) > SIZELEFT(mp)) { + DPRINTF("not enough room in page %zu, got %u ptrs", + mp->mp_pgno, NUMKEYS(mp)); + DPRINTF("upper - lower = %u - %u = %u", mp->mp_upper, mp->mp_lower, + mp->mp_upper - mp->mp_lower); + DPRINTF("node size = %zu", node_size); + return MDB_PAGE_FULL; + } + + /* Move higher pointers up one slot. */ + for (i = NUMKEYS(mp); i > indx; i--) + mp->mp_ptrs[i] = mp->mp_ptrs[i - 1]; + + /* Adjust free space offsets. */ + ofs = mp->mp_upper - node_size; + assert(ofs >= mp->mp_lower + sizeof(indx_t)); + mp->mp_ptrs[indx] = ofs; + mp->mp_upper = ofs; + mp->mp_lower += sizeof(indx_t); + + /* Write the node data. */ + node = NODEPTR(mp, indx); + node->mn_ksize = (key == NULL) ? 0 : key->mv_size; + node->mn_flags = flags; + if (IS_LEAF(mp)) + SETDSZ(node,data->mv_size); + else + SETPGNO(node,pgno); + + if (key) + memcpy(NODEKEY(node), key->mv_data, key->mv_size); + + if (IS_LEAF(mp)) { + assert(key); + if (ofp == NULL) { + if (F_ISSET(flags, F_BIGDATA)) + memcpy(node->mn_data + key->mv_size, data->mv_data, + sizeof(pgno_t)); + else if (F_ISSET(flags, MDB_RESERVE)) + data->mv_data = node->mn_data + key->mv_size; + else + memcpy(node->mn_data + key->mv_size, data->mv_data, + data->mv_size); + } else { + memcpy(node->mn_data + key->mv_size, &ofp->mp_pgno, + sizeof(pgno_t)); + if (F_ISSET(flags, MDB_RESERVE)) + data->mv_data = METADATA(ofp); + else + memcpy(METADATA(ofp), data->mv_data, data->mv_size); + } + } + + return MDB_SUCCESS; +} + +/** Delete the specified node from a page. + * @param[in] mp The page to operate on. + * @param[in] indx The index of the node to delete. + * @param[in] ksize The size of a node. Only used if the page is + * part of a #MDB_DUPFIXED database. + */ +static void +mdb_node_del(MDB_page *mp, indx_t indx, int ksize) +{ + unsigned int sz; + indx_t i, j, numkeys, ptr; + MDB_node *node; + char *base; + +#if MDB_DEBUG + { + pgno_t pgno; + COPY_PGNO(pgno, mp->mp_pgno); + DPRINTF("delete node %u on %s page %zu", indx, + IS_LEAF(mp) ? "leaf" : "branch", pgno); + } +#endif + assert(indx < NUMKEYS(mp)); + + if (IS_LEAF2(mp)) { + int x = NUMKEYS(mp) - 1 - indx; + base = LEAF2KEY(mp, indx, ksize); + if (x) + memmove(base, base + ksize, x * ksize); + mp->mp_lower -= sizeof(indx_t); + mp->mp_upper += ksize - sizeof(indx_t); + return; + } + + node = NODEPTR(mp, indx); + sz = NODESIZE + node->mn_ksize; + if (IS_LEAF(mp)) { + if (F_ISSET(node->mn_flags, F_BIGDATA)) + sz += sizeof(pgno_t); + else + sz += NODEDSZ(node); + } + sz += sz & 1; + + ptr = mp->mp_ptrs[indx]; + numkeys = NUMKEYS(mp); + for (i = j = 0; i < numkeys; i++) { + if (i != indx) { + mp->mp_ptrs[j] = mp->mp_ptrs[i]; + if (mp->mp_ptrs[i] < ptr) + mp->mp_ptrs[j] += sz; + j++; + } + } + + base = (char *)mp + mp->mp_upper; + memmove(base + sz, base, ptr - mp->mp_upper); + + mp->mp_lower -= sizeof(indx_t); + mp->mp_upper += sz; +} + +/** Compact the main page after deleting a node on a subpage. + * @param[in] mp The main page to operate on. + * @param[in] indx The index of the subpage on the main page. + */ +static void +mdb_node_shrink(MDB_page *mp, indx_t indx) +{ + MDB_node *node; + MDB_page *sp, *xp; + char *base; + int osize, nsize; + int delta; + indx_t i, numkeys, ptr; + + node = NODEPTR(mp, indx); + sp = (MDB_page *)NODEDATA(node); + osize = NODEDSZ(node); + + delta = sp->mp_upper - sp->mp_lower; + SETDSZ(node, osize - delta); + xp = (MDB_page *)((char *)sp + delta); + + /* shift subpage upward */ + if (IS_LEAF2(sp)) { + nsize = NUMKEYS(sp) * sp->mp_pad; + memmove(METADATA(xp), METADATA(sp), nsize); + } else { + int i; + nsize = osize - sp->mp_upper; + numkeys = NUMKEYS(sp); + for (i=numkeys-1; i>=0; i--) + xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta; + } + xp->mp_upper = sp->mp_lower; + xp->mp_lower = sp->mp_lower; + xp->mp_flags = sp->mp_flags; + xp->mp_pad = sp->mp_pad; + COPY_PGNO(xp->mp_pgno, mp->mp_pgno); + + /* shift lower nodes upward */ + ptr = mp->mp_ptrs[indx]; + numkeys = NUMKEYS(mp); + for (i = 0; i < numkeys; i++) { + if (mp->mp_ptrs[i] <= ptr) + mp->mp_ptrs[i] += delta; + } + + base = (char *)mp + mp->mp_upper; + memmove(base + delta, base, ptr - mp->mp_upper + NODESIZE + NODEKSZ(node)); + mp->mp_upper += delta; +} + +/** Initial setup of a sorted-dups cursor. + * Sorted duplicates are implemented as a sub-database for the given key. + * The duplicate data items are actually keys of the sub-database. + * Operations on the duplicate data items are performed using a sub-cursor + * initialized when the sub-database is first accessed. This function does + * the preliminary setup of the sub-cursor, filling in the fields that + * depend only on the parent DB. + * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized. + */ +static void +mdb_xcursor_init0(MDB_cursor *mc) +{ + MDB_xcursor *mx = mc->mc_xcursor; + + mx->mx_cursor.mc_xcursor = NULL; + mx->mx_cursor.mc_txn = mc->mc_txn; + mx->mx_cursor.mc_db = &mx->mx_db; + mx->mx_cursor.mc_dbx = &mx->mx_dbx; + mx->mx_cursor.mc_dbi = mc->mc_dbi+1; + mx->mx_cursor.mc_dbflag = &mx->mx_dbflag; + mx->mx_cursor.mc_snum = 0; + mx->mx_cursor.mc_top = 0; + mx->mx_cursor.mc_flags = C_SUB; + mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp; + mx->mx_dbx.md_dcmp = NULL; + mx->mx_dbx.md_rel = mc->mc_dbx->md_rel; +} + +/** Final setup of a sorted-dups cursor. + * Sets up the fields that depend on the data from the main cursor. + * @param[in] mc The main cursor whose sorted-dups cursor is to be initialized. + * @param[in] node The data containing the #MDB_db record for the + * sorted-dup database. + */ +static void +mdb_xcursor_init1(MDB_cursor *mc, MDB_node *node) +{ + MDB_xcursor *mx = mc->mc_xcursor; + + if (node->mn_flags & F_SUBDATA) { + memcpy(&mx->mx_db, NODEDATA(node), sizeof(MDB_db)); + mx->mx_cursor.mc_pg[0] = 0; + mx->mx_cursor.mc_snum = 0; + mx->mx_cursor.mc_flags = C_SUB; + } else { + MDB_page *fp = NODEDATA(node); + mx->mx_db.md_pad = mc->mc_pg[mc->mc_top]->mp_pad; + mx->mx_db.md_flags = 0; + mx->mx_db.md_depth = 1; + mx->mx_db.md_branch_pages = 0; + mx->mx_db.md_leaf_pages = 1; + mx->mx_db.md_overflow_pages = 0; + mx->mx_db.md_entries = NUMKEYS(fp); + COPY_PGNO(mx->mx_db.md_root, fp->mp_pgno); + mx->mx_cursor.mc_snum = 1; + mx->mx_cursor.mc_flags = C_INITIALIZED|C_SUB; + mx->mx_cursor.mc_top = 0; + mx->mx_cursor.mc_pg[0] = fp; + mx->mx_cursor.mc_ki[0] = 0; + if (mc->mc_db->md_flags & MDB_DUPFIXED) { + mx->mx_db.md_flags = MDB_DUPFIXED; + mx->mx_db.md_pad = fp->mp_pad; + if (mc->mc_db->md_flags & MDB_INTEGERDUP) + mx->mx_db.md_flags |= MDB_INTEGERKEY; + } + } + DPRINTF("Sub-db %u for db %u root page %zu", mx->mx_cursor.mc_dbi, mc->mc_dbi, + mx->mx_db.md_root); + mx->mx_dbflag = (F_ISSET(mc->mc_pg[mc->mc_top]->mp_flags, P_DIRTY)) ? + DB_DIRTY : 0; + mx->mx_dbx.md_name.mv_data = NODEKEY(node); + mx->mx_dbx.md_name.mv_size = node->mn_ksize; +#if UINT_MAX < SIZE_MAX + if (mx->mx_dbx.md_cmp == mdb_cmp_int && mx->mx_db.md_pad == sizeof(size_t)) +#ifdef MISALIGNED_OK + mx->mx_dbx.md_cmp = mdb_cmp_long; +#else + mx->mx_dbx.md_cmp = mdb_cmp_cint; +#endif +#endif +} + +/** Initialize a cursor for a given transaction and database. */ +static void +mdb_cursor_init(MDB_cursor *mc, MDB_txn *txn, MDB_dbi dbi, MDB_xcursor *mx) +{ + mc->mc_orig = NULL; + mc->mc_dbi = dbi; + mc->mc_txn = txn; + mc->mc_db = &txn->mt_dbs[dbi]; + mc->mc_dbx = &txn->mt_dbxs[dbi]; + mc->mc_dbflag = &txn->mt_dbflags[dbi]; + mc->mc_snum = 0; + mc->mc_top = 0; + mc->mc_pg[0] = 0; + mc->mc_flags = 0; + if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) { + assert(mx != NULL); + mc->mc_xcursor = mx; + mdb_xcursor_init0(mc); + } else { + mc->mc_xcursor = NULL; + } + if (*mc->mc_dbflag & DB_STALE) { + mdb_page_search(mc, NULL, MDB_PS_ROOTONLY); + } +} + +int +mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **ret) +{ + MDB_cursor *mc; + MDB_xcursor *mx = NULL; + size_t size = sizeof(MDB_cursor); + + if (txn == NULL || ret == NULL || dbi >= txn->mt_numdbs) + return EINVAL; + + /* Allow read access to the freelist */ + if (!dbi && !F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) + return EINVAL; + + if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) + size += sizeof(MDB_xcursor); + + if ((mc = malloc(size)) != NULL) { + if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) { + mx = (MDB_xcursor *)(mc + 1); + } + mdb_cursor_init(mc, txn, dbi, mx); + if (txn->mt_cursors) { + mc->mc_next = txn->mt_cursors[dbi]; + txn->mt_cursors[dbi] = mc; + } + mc->mc_flags |= C_ALLOCD; + } else { + return ENOMEM; + } + + *ret = mc; + + return MDB_SUCCESS; +} + +int +mdb_cursor_renew(MDB_txn *txn, MDB_cursor *mc) +{ + if (txn == NULL || mc == NULL || mc->mc_dbi >= txn->mt_numdbs) + return EINVAL; + + if (txn->mt_cursors) + return EINVAL; + + mdb_cursor_init(mc, txn, mc->mc_dbi, mc->mc_xcursor); + return MDB_SUCCESS; +} + +/* Return the count of duplicate data items for the current key */ +int +mdb_cursor_count(MDB_cursor *mc, size_t *countp) +{ + MDB_node *leaf; + + if (mc == NULL || countp == NULL) + return EINVAL; + + if (!(mc->mc_db->md_flags & MDB_DUPSORT)) + return EINVAL; + + leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]); + if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) { + *countp = 1; + } else { + if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) + return EINVAL; + + *countp = mc->mc_xcursor->mx_db.md_entries; + } + return MDB_SUCCESS; +} + +void +mdb_cursor_close(MDB_cursor *mc) +{ + if (mc != NULL) { + /* remove from txn, if tracked */ + if (mc->mc_txn->mt_cursors) { + MDB_cursor **prev = &mc->mc_txn->mt_cursors[mc->mc_dbi]; + while (*prev && *prev != mc) prev = &(*prev)->mc_next; + if (*prev == mc) + *prev = mc->mc_next; + } + if (mc->mc_flags & C_ALLOCD) + free(mc); + } +} + +MDB_txn * +mdb_cursor_txn(MDB_cursor *mc) +{ + if (!mc) return NULL; + return mc->mc_txn; +} + +MDB_dbi +mdb_cursor_dbi(MDB_cursor *mc) +{ + if (!mc) return 0; + return mc->mc_dbi; +} + +/** Replace the key for a node with a new key. + * @param[in] mp The page containing the node to operate on. + * @param[in] indx The index of the node to operate on. + * @param[in] key The new key to use. + * @return 0 on success, non-zero on failure. + */ +static int +mdb_update_key(MDB_page *mp, indx_t indx, MDB_val *key) +{ + MDB_node *node; + char *base; + size_t len; + int delta, delta0; + indx_t ptr, i, numkeys; + DKBUF; + + node = NODEPTR(mp, indx); + ptr = mp->mp_ptrs[indx]; +#if MDB_DEBUG + { + MDB_val k2; + char kbuf2[(MAXKEYSIZE*2+1)]; + k2.mv_data = NODEKEY(node); + k2.mv_size = node->mn_ksize; + DPRINTF("update key %u (ofs %u) [%s] to [%s] on page %zu", + indx, ptr, + mdb_dkey(&k2, kbuf2), + DKEY(key), + mp->mp_pgno); + } +#endif + + delta0 = delta = key->mv_size - node->mn_ksize; + + /* Must be 2-byte aligned. If new key is + * shorter by 1, the shift will be skipped. + */ + delta += (delta & 1); + if (delta) { + if (delta > 0 && SIZELEFT(mp) < delta) { + DPRINTF("OUCH! Not enough room, delta = %d", delta); + return MDB_PAGE_FULL; + } + + numkeys = NUMKEYS(mp); + for (i = 0; i < numkeys; i++) { + if (mp->mp_ptrs[i] <= ptr) + mp->mp_ptrs[i] -= delta; + } + + base = (char *)mp + mp->mp_upper; + len = ptr - mp->mp_upper + NODESIZE; + memmove(base - delta, base, len); + mp->mp_upper -= delta; + + node = NODEPTR(mp, indx); + } + + /* But even if no shift was needed, update ksize */ + if (delta0) + node->mn_ksize = key->mv_size; + + if (key->mv_size) + memcpy(NODEKEY(node), key->mv_data, key->mv_size); + + return MDB_SUCCESS; +} + +/** Move a node from csrc to cdst. + */ +static int +mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst) +{ + int rc; + MDB_node *srcnode; + MDB_val key, data; + pgno_t srcpg; + unsigned short flags; + + DKBUF; + + /* Mark src and dst as dirty. */ + if ((rc = mdb_page_touch(csrc)) || + (rc = mdb_page_touch(cdst))) + return rc; + + if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { + srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); /* fake */ + key.mv_size = csrc->mc_db->md_pad; + key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size); + data.mv_size = 0; + data.mv_data = NULL; + srcpg = 0; + flags = 0; + } else { + srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top]); + assert(!((long)srcnode&1)); + srcpg = NODEPGNO(srcnode); + flags = srcnode->mn_flags; + if (csrc->mc_ki[csrc->mc_top] == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) { + unsigned int snum = csrc->mc_snum; + MDB_node *s2; + /* must find the lowest key below src */ + mdb_page_search_root(csrc, NULL, 0); + if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { + key.mv_size = csrc->mc_db->md_pad; + key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size); + } else { + s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); + key.mv_size = NODEKSZ(s2); + key.mv_data = NODEKEY(s2); + } + csrc->mc_snum = snum--; + csrc->mc_top = snum; + } else { + key.mv_size = NODEKSZ(srcnode); + key.mv_data = NODEKEY(srcnode); + } + data.mv_size = NODEDSZ(srcnode); + data.mv_data = NODEDATA(srcnode); + } + if (IS_BRANCH(cdst->mc_pg[cdst->mc_top]) && cdst->mc_ki[cdst->mc_top] == 0) { + unsigned int snum = cdst->mc_snum; + MDB_node *s2; + MDB_val bkey; + /* must find the lowest key below dst */ + mdb_page_search_root(cdst, NULL, 0); + if (IS_LEAF2(cdst->mc_pg[cdst->mc_top])) { + bkey.mv_size = cdst->mc_db->md_pad; + bkey.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, bkey.mv_size); + } else { + s2 = NODEPTR(cdst->mc_pg[cdst->mc_top], 0); + bkey.mv_size = NODEKSZ(s2); + bkey.mv_data = NODEKEY(s2); + } + cdst->mc_snum = snum--; + cdst->mc_top = snum; + rc = mdb_update_key(cdst->mc_pg[cdst->mc_top], 0, &bkey); + } + + DPRINTF("moving %s node %u [%s] on page %zu to node %u on page %zu", + IS_LEAF(csrc->mc_pg[csrc->mc_top]) ? "leaf" : "branch", + csrc->mc_ki[csrc->mc_top], + DKEY(&key), + csrc->mc_pg[csrc->mc_top]->mp_pgno, + cdst->mc_ki[cdst->mc_top], cdst->mc_pg[cdst->mc_top]->mp_pgno); + + /* Add the node to the destination page. + */ + rc = mdb_node_add(cdst, cdst->mc_ki[cdst->mc_top], &key, &data, srcpg, flags); + if (rc != MDB_SUCCESS) + return rc; + + /* Delete the node from the source page. + */ + mdb_node_del(csrc->mc_pg[csrc->mc_top], csrc->mc_ki[csrc->mc_top], key.mv_size); + + { + /* Adjust other cursors pointing to mp */ + MDB_cursor *m2, *m3; + MDB_dbi dbi = csrc->mc_dbi; + MDB_page *mp = csrc->mc_pg[csrc->mc_top]; + + if (csrc->mc_flags & C_SUB) + dbi--; + + for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { + if (m2 == csrc) continue; + if (csrc->mc_flags & C_SUB) + m3 = &m2->mc_xcursor->mx_cursor; + else + m3 = m2; + if (m3->mc_pg[csrc->mc_top] == mp && m3->mc_ki[csrc->mc_top] == + csrc->mc_ki[csrc->mc_top]) { + m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top]; + m3->mc_ki[csrc->mc_top] = cdst->mc_ki[cdst->mc_top]; + } + } + } + + /* Update the parent separators. + */ + if (csrc->mc_ki[csrc->mc_top] == 0) { + if (csrc->mc_ki[csrc->mc_top-1] != 0) { + if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { + key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size); + } else { + srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); + key.mv_size = NODEKSZ(srcnode); + key.mv_data = NODEKEY(srcnode); + } + DPRINTF("update separator for source page %zu to [%s]", + csrc->mc_pg[csrc->mc_top]->mp_pgno, DKEY(&key)); + if ((rc = mdb_update_key(csrc->mc_pg[csrc->mc_top-1], csrc->mc_ki[csrc->mc_top-1], + &key)) != MDB_SUCCESS) + return rc; + } + if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) { + MDB_val nullkey; + nullkey.mv_size = 0; + rc = mdb_update_key(csrc->mc_pg[csrc->mc_top], 0, &nullkey); + assert(rc == MDB_SUCCESS); + } + } + + if (cdst->mc_ki[cdst->mc_top] == 0) { + if (cdst->mc_ki[cdst->mc_top-1] != 0) { + if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { + key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size); + } else { + srcnode = NODEPTR(cdst->mc_pg[cdst->mc_top], 0); + key.mv_size = NODEKSZ(srcnode); + key.mv_data = NODEKEY(srcnode); + } + DPRINTF("update separator for destination page %zu to [%s]", + cdst->mc_pg[cdst->mc_top]->mp_pgno, DKEY(&key)); + if ((rc = mdb_update_key(cdst->mc_pg[cdst->mc_top-1], cdst->mc_ki[cdst->mc_top-1], + &key)) != MDB_SUCCESS) + return rc; + } + if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) { + MDB_val nullkey; + nullkey.mv_size = 0; + rc = mdb_update_key(cdst->mc_pg[cdst->mc_top], 0, &nullkey); + assert(rc == MDB_SUCCESS); + } + } + + return MDB_SUCCESS; +} + +/** Merge one page into another. + * The nodes from the page pointed to by \b csrc will + * be copied to the page pointed to by \b cdst and then + * the \b csrc page will be freed. + * @param[in] csrc Cursor pointing to the source page. + * @param[in] cdst Cursor pointing to the destination page. + */ +static int +mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst) +{ + int rc; + indx_t i, j; + MDB_node *srcnode; + MDB_val key, data; + unsigned nkeys; + + DPRINTF("merging page %zu into %zu", csrc->mc_pg[csrc->mc_top]->mp_pgno, + cdst->mc_pg[cdst->mc_top]->mp_pgno); + + assert(csrc->mc_snum > 1); /* can't merge root page */ + assert(cdst->mc_snum > 1); + + /* Mark dst as dirty. */ + if ((rc = mdb_page_touch(cdst))) + return rc; + + /* Move all nodes from src to dst. + */ + j = nkeys = NUMKEYS(cdst->mc_pg[cdst->mc_top]); + if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { + key.mv_size = csrc->mc_db->md_pad; + key.mv_data = METADATA(csrc->mc_pg[csrc->mc_top]); + for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) { + rc = mdb_node_add(cdst, j, &key, NULL, 0, 0); + if (rc != MDB_SUCCESS) + return rc; + key.mv_data = (char *)key.mv_data + key.mv_size; + } + } else { + for (i = 0; i < NUMKEYS(csrc->mc_pg[csrc->mc_top]); i++, j++) { + srcnode = NODEPTR(csrc->mc_pg[csrc->mc_top], i); + if (i == 0 && IS_BRANCH(csrc->mc_pg[csrc->mc_top])) { + unsigned int snum = csrc->mc_snum; + MDB_node *s2; + /* must find the lowest key below src */ + mdb_page_search_root(csrc, NULL, 0); + if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) { + key.mv_size = csrc->mc_db->md_pad; + key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size); + } else { + s2 = NODEPTR(csrc->mc_pg[csrc->mc_top], 0); + key.mv_size = NODEKSZ(s2); + key.mv_data = NODEKEY(s2); + } + csrc->mc_snum = snum--; + csrc->mc_top = snum; + } else { + key.mv_size = srcnode->mn_ksize; + key.mv_data = NODEKEY(srcnode); + } + + data.mv_size = NODEDSZ(srcnode); + data.mv_data = NODEDATA(srcnode); + rc = mdb_node_add(cdst, j, &key, &data, NODEPGNO(srcnode), srcnode->mn_flags); + if (rc != MDB_SUCCESS) + return rc; + } + } + + DPRINTF("dst page %zu now has %u keys (%.1f%% filled)", + cdst->mc_pg[cdst->mc_top]->mp_pgno, NUMKEYS(cdst->mc_pg[cdst->mc_top]), (float)PAGEFILL(cdst->mc_txn->mt_env, cdst->mc_pg[cdst->mc_top]) / 10); + + /* Unlink the src page from parent and add to free list. + */ + mdb_node_del(csrc->mc_pg[csrc->mc_top-1], csrc->mc_ki[csrc->mc_top-1], 0); + if (csrc->mc_ki[csrc->mc_top-1] == 0) { + key.mv_size = 0; + if ((rc = mdb_update_key(csrc->mc_pg[csrc->mc_top-1], 0, &key)) != MDB_SUCCESS) + return rc; + } + + mdb_midl_append(&csrc->mc_txn->mt_free_pgs, csrc->mc_pg[csrc->mc_top]->mp_pgno); + if (IS_LEAF(csrc->mc_pg[csrc->mc_top])) + csrc->mc_db->md_leaf_pages--; + else + csrc->mc_db->md_branch_pages--; + { + /* Adjust other cursors pointing to mp */ + MDB_cursor *m2, *m3; + MDB_dbi dbi = csrc->mc_dbi; + MDB_page *mp = cdst->mc_pg[cdst->mc_top]; + + if (csrc->mc_flags & C_SUB) + dbi--; + + for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { + if (csrc->mc_flags & C_SUB) + m3 = &m2->mc_xcursor->mx_cursor; + else + m3 = m2; + if (m3 == csrc) continue; + if (m3->mc_snum < csrc->mc_snum) continue; + if (m3->mc_pg[csrc->mc_top] == csrc->mc_pg[csrc->mc_top]) { + m3->mc_pg[csrc->mc_top] = mp; + m3->mc_ki[csrc->mc_top] += nkeys; + } + } + } + mdb_cursor_pop(csrc); + + return mdb_rebalance(csrc); +} + +/** Copy the contents of a cursor. + * @param[in] csrc The cursor to copy from. + * @param[out] cdst The cursor to copy to. + */ +static void +mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst) +{ + unsigned int i; + + cdst->mc_txn = csrc->mc_txn; + cdst->mc_dbi = csrc->mc_dbi; + cdst->mc_db = csrc->mc_db; + cdst->mc_dbx = csrc->mc_dbx; + cdst->mc_snum = csrc->mc_snum; + cdst->mc_top = csrc->mc_top; + cdst->mc_flags = csrc->mc_flags; + + for (i=0; imc_snum; i++) { + cdst->mc_pg[i] = csrc->mc_pg[i]; + cdst->mc_ki[i] = csrc->mc_ki[i]; + } +} + +/** Rebalance the tree after a delete operation. + * @param[in] mc Cursor pointing to the page where rebalancing + * should begin. + * @return 0 on success, non-zero on failure. + */ +static int +mdb_rebalance(MDB_cursor *mc) +{ + MDB_node *node; + int rc; + unsigned int ptop; + MDB_cursor mn; + +#if MDB_DEBUG + { + pgno_t pgno; + COPY_PGNO(pgno, mc->mc_pg[mc->mc_top]->mp_pgno); + DPRINTF("rebalancing %s page %zu (has %u keys, %.1f%% full)", + IS_LEAF(mc->mc_pg[mc->mc_top]) ? "leaf" : "branch", + pgno, NUMKEYS(mc->mc_pg[mc->mc_top]), (float)PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) / 10); + } +#endif + + if (PAGEFILL(mc->mc_txn->mt_env, mc->mc_pg[mc->mc_top]) >= FILL_THRESHOLD) { +#if MDB_DEBUG + pgno_t pgno; + COPY_PGNO(pgno, mc->mc_pg[mc->mc_top]->mp_pgno); + DPRINTF("no need to rebalance page %zu, above fill threshold", + pgno); +#endif + return MDB_SUCCESS; + } + + if (mc->mc_snum < 2) { + MDB_page *mp = mc->mc_pg[0]; + if (NUMKEYS(mp) == 0) { + DPUTS("tree is completely empty"); + mc->mc_db->md_root = P_INVALID; + mc->mc_db->md_depth = 0; + mc->mc_db->md_leaf_pages = 0; + mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno); + mc->mc_snum = 0; + mc->mc_top = 0; + { + /* Adjust other cursors pointing to mp */ + MDB_cursor *m2, *m3; + MDB_dbi dbi = mc->mc_dbi; + + if (mc->mc_flags & C_SUB) + dbi--; + + for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { + if (m2 == mc) continue; + if (mc->mc_flags & C_SUB) + m3 = &m2->mc_xcursor->mx_cursor; + else + m3 = m2; + if (m3->mc_snum < mc->mc_snum) continue; + if (m3->mc_pg[0] == mp) { + m3->mc_snum = 0; + m3->mc_top = 0; + } + } + } + } else if (IS_BRANCH(mp) && NUMKEYS(mp) == 1) { + DPUTS("collapsing root page!"); + mdb_midl_append(&mc->mc_txn->mt_free_pgs, mp->mp_pgno); + mc->mc_db->md_root = NODEPGNO(NODEPTR(mp, 0)); + if ((rc = mdb_page_get(mc->mc_txn, mc->mc_db->md_root, + &mc->mc_pg[0]))) + return rc; + mc->mc_db->md_depth--; + mc->mc_db->md_branch_pages--; + { + /* Adjust other cursors pointing to mp */ + MDB_cursor *m2, *m3; + MDB_dbi dbi = mc->mc_dbi; + + if (mc->mc_flags & C_SUB) + dbi--; + + for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { + if (m2 == mc) continue; + if (mc->mc_flags & C_SUB) + m3 = &m2->mc_xcursor->mx_cursor; + else + m3 = m2; + if (m3->mc_snum < mc->mc_snum) continue; + if (m3->mc_pg[0] == mp) { + m3->mc_pg[0] = mc->mc_pg[0]; + } + } + } + } else + DPUTS("root page doesn't need rebalancing"); + return MDB_SUCCESS; + } + + /* The parent (branch page) must have at least 2 pointers, + * otherwise the tree is invalid. + */ + ptop = mc->mc_top-1; + assert(NUMKEYS(mc->mc_pg[ptop]) > 1); + + /* Leaf page fill factor is below the threshold. + * Try to move keys from left or right neighbor, or + * merge with a neighbor page. + */ + + /* Find neighbors. + */ + mdb_cursor_copy(mc, &mn); + mn.mc_xcursor = NULL; + + if (mc->mc_ki[ptop] == 0) { + /* We're the leftmost leaf in our parent. + */ + DPUTS("reading right neighbor"); + mn.mc_ki[ptop]++; + node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]); + if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mn.mc_pg[mn.mc_top]))) + return rc; + mn.mc_ki[mn.mc_top] = 0; + mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]); + } else { + /* There is at least one neighbor to the left. + */ + DPUTS("reading left neighbor"); + mn.mc_ki[ptop]--; + node = NODEPTR(mc->mc_pg[ptop], mn.mc_ki[ptop]); + if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mn.mc_pg[mn.mc_top]))) + return rc; + mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1; + mc->mc_ki[mc->mc_top] = 0; + } + + DPRINTF("found neighbor page %zu (%u keys, %.1f%% full)", + mn.mc_pg[mn.mc_top]->mp_pgno, NUMKEYS(mn.mc_pg[mn.mc_top]), (float)PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) / 10); + + /* If the neighbor page is above threshold and has at least two + * keys, move one key from it. + * + * Otherwise we should try to merge them. + */ + if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= FILL_THRESHOLD && NUMKEYS(mn.mc_pg[mn.mc_top]) >= 2) + return mdb_node_move(&mn, mc); + else { /* FIXME: if (has_enough_room()) */ + mc->mc_flags &= ~C_INITIALIZED; + if (mc->mc_ki[ptop] == 0) + return mdb_page_merge(&mn, mc); + else + return mdb_page_merge(mc, &mn); + } +} + +/** Complete a delete operation started by #mdb_cursor_del(). */ +static int +mdb_cursor_del0(MDB_cursor *mc, MDB_node *leaf) +{ + int rc; + + /* add overflow pages to free list */ + if (!IS_LEAF2(mc->mc_pg[mc->mc_top]) && F_ISSET(leaf->mn_flags, F_BIGDATA)) { + int i, ovpages; + pgno_t pg; + + memcpy(&pg, NODEDATA(leaf), sizeof(pg)); + ovpages = OVPAGES(NODEDSZ(leaf), mc->mc_txn->mt_env->me_psize); + mc->mc_db->md_overflow_pages -= ovpages; + for (i=0; imc_txn->mt_free_pgs, pg); + pg++; + } + } + mdb_node_del(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top], mc->mc_db->md_pad); + mc->mc_db->md_entries--; + rc = mdb_rebalance(mc); + if (rc != MDB_SUCCESS) + mc->mc_txn->mt_flags |= MDB_TXN_ERROR; + + return rc; +} + +int +mdb_del(MDB_txn *txn, MDB_dbi dbi, + MDB_val *key, MDB_val *data) +{ + MDB_cursor mc; + MDB_xcursor mx; + MDB_cursor_op op; + MDB_val rdata, *xdata; + int rc, exact; + DKBUF; + + assert(key != NULL); + + DPRINTF("====> delete db %u key [%s]", dbi, DKEY(key)); + + if (txn == NULL || !dbi || dbi >= txn->mt_numdbs) + return EINVAL; + + if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) { + return EACCES; + } + + if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) { + return EINVAL; + } + + mdb_cursor_init(&mc, txn, dbi, &mx); + + exact = 0; + if (data) { + op = MDB_GET_BOTH; + rdata = *data; + xdata = &rdata; + } else { + op = MDB_SET; + xdata = NULL; + } + rc = mdb_cursor_set(&mc, key, xdata, op, &exact); + if (rc == 0) + rc = mdb_cursor_del(&mc, data ? 0 : MDB_NODUPDATA); + return rc; +} + +/** Split a page and insert a new node. + * @param[in,out] mc Cursor pointing to the page and desired insertion index. + * The cursor will be updated to point to the actual page and index where + * the node got inserted after the split. + * @param[in] newkey The key for the newly inserted node. + * @param[in] newdata The data for the newly inserted node. + * @param[in] newpgno The page number, if the new node is a branch node. + * @param[in] nflags The #NODE_ADD_FLAGS for the new node. + * @return 0 on success, non-zero on failure. + */ +static int +mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno, + unsigned int nflags) +{ + unsigned int flags; + int rc = MDB_SUCCESS, ins_new = 0, new_root = 0, newpos = 1, did_split = 0; + indx_t newindx; + pgno_t pgno = 0; + unsigned int i, j, split_indx, nkeys, pmax; + MDB_node *node; + MDB_val sepkey, rkey, xdata, *rdata = &xdata; + MDB_page *copy; + MDB_page *mp, *rp, *pp; + unsigned int ptop; + MDB_cursor mn; + DKBUF; + + mp = mc->mc_pg[mc->mc_top]; + newindx = mc->mc_ki[mc->mc_top]; + + DPRINTF("-----> splitting %s page %zu and adding [%s] at index %i", + IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno, + DKEY(newkey), mc->mc_ki[mc->mc_top]); + + /* Create a right sibling. */ + if ((rc = mdb_page_new(mc, mp->mp_flags, 1, &rp))) + return rc; + DPRINTF("new right sibling: page %zu", rp->mp_pgno); + + if (mc->mc_snum < 2) { + if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp))) + return rc; + /* shift current top to make room for new parent */ + mc->mc_pg[1] = mc->mc_pg[0]; + mc->mc_ki[1] = mc->mc_ki[0]; + mc->mc_pg[0] = pp; + mc->mc_ki[0] = 0; + mc->mc_db->md_root = pp->mp_pgno; + DPRINTF("root split! new root = %zu", pp->mp_pgno); + mc->mc_db->md_depth++; + new_root = 1; + + /* Add left (implicit) pointer. */ + if ((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS) { + /* undo the pre-push */ + mc->mc_pg[0] = mc->mc_pg[1]; + mc->mc_ki[0] = mc->mc_ki[1]; + mc->mc_db->md_root = mp->mp_pgno; + mc->mc_db->md_depth--; + return rc; + } + mc->mc_snum = 2; + mc->mc_top = 1; + ptop = 0; + } else { + ptop = mc->mc_top-1; + DPRINTF("parent branch page is %zu", mc->mc_pg[ptop]->mp_pgno); + } + + mc->mc_flags |= C_SPLITTING; + mdb_cursor_copy(mc, &mn); + mn.mc_pg[mn.mc_top] = rp; + mn.mc_ki[ptop] = mc->mc_ki[ptop]+1; + + if (nflags & MDB_APPEND) { + mn.mc_ki[mn.mc_top] = 0; + sepkey = *newkey; + split_indx = newindx; + nkeys = 0; + goto newsep; + } + + nkeys = NUMKEYS(mp); + split_indx = nkeys / 2; + if (newindx < split_indx) + newpos = 0; + + if (IS_LEAF2(rp)) { + char *split, *ins; + int x; + unsigned int lsize, rsize, ksize; + /* Move half of the keys to the right sibling */ + copy = NULL; + x = mc->mc_ki[mc->mc_top] - split_indx; + ksize = mc->mc_db->md_pad; + split = LEAF2KEY(mp, split_indx, ksize); + rsize = (nkeys - split_indx) * ksize; + lsize = (nkeys - split_indx) * sizeof(indx_t); + mp->mp_lower -= lsize; + rp->mp_lower += lsize; + mp->mp_upper += rsize - lsize; + rp->mp_upper -= rsize - lsize; + sepkey.mv_size = ksize; + if (newindx == split_indx) { + sepkey.mv_data = newkey->mv_data; + } else { + sepkey.mv_data = split; + } + if (x<0) { + ins = LEAF2KEY(mp, mc->mc_ki[mc->mc_top], ksize); + memcpy(rp->mp_ptrs, split, rsize); + sepkey.mv_data = rp->mp_ptrs; + memmove(ins+ksize, ins, (split_indx - mc->mc_ki[mc->mc_top]) * ksize); + memcpy(ins, newkey->mv_data, ksize); + mp->mp_lower += sizeof(indx_t); + mp->mp_upper -= ksize - sizeof(indx_t); + } else { + if (x) + memcpy(rp->mp_ptrs, split, x * ksize); + ins = LEAF2KEY(rp, x, ksize); + memcpy(ins, newkey->mv_data, ksize); + memcpy(ins+ksize, split + x * ksize, rsize - x * ksize); + rp->mp_lower += sizeof(indx_t); + rp->mp_upper -= ksize - sizeof(indx_t); + mc->mc_ki[mc->mc_top] = x; + mc->mc_pg[mc->mc_top] = rp; + } + goto newsep; + } + + /* For leaf pages, check the split point based on what + * fits where, since otherwise mdb_node_add can fail. + * + * This check is only needed when the data items are + * relatively large, such that being off by one will + * make the difference between success or failure. + * + * It's also relevant if a page happens to be laid out + * such that one half of its nodes are all "small" and + * the other half of its nodes are "large." If the new + * item is also "large" and falls on the half with + * "large" nodes, it also may not fit. + */ + if (IS_LEAF(mp)) { + unsigned int psize, nsize; + /* Maximum free space in an empty page */ + pmax = mc->mc_txn->mt_env->me_psize - PAGEHDRSZ; + nsize = mdb_leaf_size(mc->mc_txn->mt_env, newkey, newdata); + if ((nkeys < 20) || (nsize > pmax/16)) { + if (newindx <= split_indx) { + psize = nsize; + newpos = 0; + for (i=0; imn_flags, F_BIGDATA)) + psize += sizeof(pgno_t); + else + psize += NODEDSZ(node); + psize += psize & 1; + if (psize > pmax) { + if (i <= newindx) { + split_indx = newindx; + if (i < newindx) + newpos = 1; + } + else + split_indx = i; + break; + } + } + } else { + psize = nsize; + for (i=nkeys-1; i>=split_indx; i--) { + node = NODEPTR(mp, i); + psize += NODESIZE + NODEKSZ(node) + sizeof(indx_t); + if (F_ISSET(node->mn_flags, F_BIGDATA)) + psize += sizeof(pgno_t); + else + psize += NODEDSZ(node); + psize += psize & 1; + if (psize > pmax) { + if (i >= newindx) { + split_indx = newindx; + newpos = 0; + } else + split_indx = i+1; + break; + } + } + } + } + } + + /* First find the separating key between the split pages. + * The case where newindx == split_indx is ambiguous; the + * new item could go to the new page or stay on the original + * page. If newpos == 1 it goes to the new page. + */ + if (newindx == split_indx && newpos) { + sepkey.mv_size = newkey->mv_size; + sepkey.mv_data = newkey->mv_data; + } else { + node = NODEPTR(mp, split_indx); + sepkey.mv_size = node->mn_ksize; + sepkey.mv_data = NODEKEY(node); + } + +newsep: + DPRINTF("separator is [%s]", DKEY(&sepkey)); + + /* Copy separator key to the parent. + */ + if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(mc->mc_txn->mt_env, &sepkey)) { + mn.mc_snum--; + mn.mc_top--; + did_split = 1; + rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0); + + /* root split? */ + if (mn.mc_snum == mc->mc_snum) { + mc->mc_pg[mc->mc_snum] = mc->mc_pg[mc->mc_top]; + mc->mc_ki[mc->mc_snum] = mc->mc_ki[mc->mc_top]; + mc->mc_pg[mc->mc_top] = mc->mc_pg[ptop]; + mc->mc_ki[mc->mc_top] = mc->mc_ki[ptop]; + mc->mc_snum++; + mc->mc_top++; + ptop++; + } + /* Right page might now have changed parent. + * Check if left page also changed parent. + */ + if (mn.mc_pg[ptop] != mc->mc_pg[ptop] && + mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) { + for (i=0; imc_pg[i] = mn.mc_pg[i]; + mc->mc_ki[i] = mn.mc_ki[i]; + } + mc->mc_pg[ptop] = mn.mc_pg[ptop]; + mc->mc_ki[ptop] = mn.mc_ki[ptop] - 1; + } + } else { + mn.mc_top--; + rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0); + mn.mc_top++; + } + mc->mc_flags ^= C_SPLITTING; + if (rc != MDB_SUCCESS) { + return rc; + } + if (nflags & MDB_APPEND) { + mc->mc_pg[mc->mc_top] = rp; + mc->mc_ki[mc->mc_top] = 0; + rc = mdb_node_add(mc, 0, newkey, newdata, newpgno, nflags); + if (rc) + return rc; + for (i=0; imc_top; i++) + mc->mc_ki[i] = mn.mc_ki[i]; + goto done; + } + if (IS_LEAF2(rp)) { + goto done; + } + + /* Move half of the keys to the right sibling. */ + + /* grab a page to hold a temporary copy */ + copy = mdb_page_malloc(mc); + if (copy == NULL) + return ENOMEM; + + copy->mp_pgno = mp->mp_pgno; + copy->mp_flags = mp->mp_flags; + copy->mp_lower = PAGEHDRSZ; + copy->mp_upper = mc->mc_txn->mt_env->me_psize; + mc->mc_pg[mc->mc_top] = copy; + for (i = j = 0; i <= nkeys; j++) { + if (i == split_indx) { + /* Insert in right sibling. */ + /* Reset insert index for right sibling. */ + if (i != newindx || (newpos ^ ins_new)) { + j = 0; + mc->mc_pg[mc->mc_top] = rp; + } + } + + if (i == newindx && !ins_new) { + /* Insert the original entry that caused the split. */ + rkey.mv_data = newkey->mv_data; + rkey.mv_size = newkey->mv_size; + if (IS_LEAF(mp)) { + rdata = newdata; + } else + pgno = newpgno; + flags = nflags; + + ins_new = 1; + + /* Update index for the new key. */ + mc->mc_ki[mc->mc_top] = j; + } else if (i == nkeys) { + break; + } else { + node = NODEPTR(mp, i); + rkey.mv_data = NODEKEY(node); + rkey.mv_size = node->mn_ksize; + if (IS_LEAF(mp)) { + xdata.mv_data = NODEDATA(node); + xdata.mv_size = NODEDSZ(node); + rdata = &xdata; + } else + pgno = NODEPGNO(node); + flags = node->mn_flags; + + i++; + } + + if (!IS_LEAF(mp) && j == 0) { + /* First branch index doesn't need key data. */ + rkey.mv_size = 0; + } + + rc = mdb_node_add(mc, j, &rkey, rdata, pgno, flags); + if (rc) break; + } + + nkeys = NUMKEYS(copy); + for (i=0; imp_ptrs[i] = copy->mp_ptrs[i]; + mp->mp_lower = copy->mp_lower; + mp->mp_upper = copy->mp_upper; + memcpy(NODEPTR(mp, nkeys-1), NODEPTR(copy, nkeys-1), + mc->mc_txn->mt_env->me_psize - copy->mp_upper); + + /* reset back to original page */ + if (newindx < split_indx || (!newpos && newindx == split_indx)) { + mc->mc_pg[mc->mc_top] = mp; + if (nflags & MDB_RESERVE) { + node = NODEPTR(mp, mc->mc_ki[mc->mc_top]); + if (!(node->mn_flags & F_BIGDATA)) + newdata->mv_data = NODEDATA(node); + } + } else { + mc->mc_ki[ptop]++; + } + + /* return tmp page to freelist */ + copy->mp_next = mc->mc_txn->mt_env->me_dpages; + VGMEMP_FREE(mc->mc_txn->mt_env, copy); + mc->mc_txn->mt_env->me_dpages = copy; +done: + { + /* Adjust other cursors pointing to mp */ + MDB_cursor *m2, *m3; + MDB_dbi dbi = mc->mc_dbi; + int fixup = NUMKEYS(mp); + + if (mc->mc_flags & C_SUB) + dbi--; + + for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) { + if (m2 == mc) continue; + if (mc->mc_flags & C_SUB) + m3 = &m2->mc_xcursor->mx_cursor; + else + m3 = m2; + if (!(m3->mc_flags & C_INITIALIZED)) + continue; + if (m3->mc_flags & C_SPLITTING) + continue; + if (new_root) { + int k; + /* root split */ + for (k=m3->mc_top; k>=0; k--) { + m3->mc_ki[k+1] = m3->mc_ki[k]; + m3->mc_pg[k+1] = m3->mc_pg[k]; + } + if (m3->mc_ki[0] >= split_indx) { + m3->mc_ki[0] = 1; + } else { + m3->mc_ki[0] = 0; + } + m3->mc_pg[0] = mc->mc_pg[0]; + m3->mc_snum++; + m3->mc_top++; + } + if (m3->mc_pg[mc->mc_top] == mp) { + if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE)) + m3->mc_ki[mc->mc_top]++; + if (m3->mc_ki[mc->mc_top] >= fixup) { + m3->mc_pg[mc->mc_top] = rp; + m3->mc_ki[mc->mc_top] -= fixup; + m3->mc_ki[ptop] = mn.mc_ki[ptop]; + } + } else if (!did_split && m3->mc_pg[ptop] == mc->mc_pg[ptop] && + m3->mc_ki[ptop] >= mc->mc_ki[ptop]) { + m3->mc_ki[ptop]++; + } + } + } + return rc; +} + +int +mdb_put(MDB_txn *txn, MDB_dbi dbi, + MDB_val *key, MDB_val *data, unsigned int flags) +{ + MDB_cursor mc; + MDB_xcursor mx; + + assert(key != NULL); + assert(data != NULL); + + if (txn == NULL || !dbi || dbi >= txn->mt_numdbs) + return EINVAL; + + if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) { + return EACCES; + } + + if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) { + return EINVAL; + } + + if ((flags & (MDB_NOOVERWRITE|MDB_NODUPDATA|MDB_RESERVE|MDB_APPEND)) != flags) + return EINVAL; + + mdb_cursor_init(&mc, txn, dbi, &mx); + return mdb_cursor_put(&mc, key, data, flags); +} + +/** Only a subset of the @ref mdb_env flags can be changed + * at runtime. Changing other flags requires closing the environment + * and re-opening it with the new flags. + */ +#define CHANGEABLE (MDB_NOSYNC|MDB_NOMETASYNC|MDB_MAPASYNC) +int +mdb_env_set_flags(MDB_env *env, unsigned int flag, int onoff) +{ + if ((flag & CHANGEABLE) != flag) + return EINVAL; + if (onoff) + env->me_flags |= flag; + else + env->me_flags &= ~flag; + return MDB_SUCCESS; +} + +int +mdb_env_get_flags(MDB_env *env, unsigned int *arg) +{ + if (!env || !arg) + return EINVAL; + + *arg = env->me_flags; + return MDB_SUCCESS; +} + +int +mdb_env_get_path(MDB_env *env, const char **arg) +{ + if (!env || !arg) + return EINVAL; + + *arg = env->me_path; + return MDB_SUCCESS; +} + +/** Common code for #mdb_stat() and #mdb_env_stat(). + * @param[in] env the environment to operate in. + * @param[in] db the #MDB_db record containing the stats to return. + * @param[out] arg the address of an #MDB_stat structure to receive the stats. + * @return 0, this function always succeeds. + */ +static int +mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg) +{ + arg->ms_psize = env->me_psize; + arg->ms_depth = db->md_depth; + arg->ms_branch_pages = db->md_branch_pages; + arg->ms_leaf_pages = db->md_leaf_pages; + arg->ms_overflow_pages = db->md_overflow_pages; + arg->ms_entries = db->md_entries; + + return MDB_SUCCESS; +} +int +mdb_env_stat(MDB_env *env, MDB_stat *arg) +{ + int toggle; + + if (env == NULL || arg == NULL) + return EINVAL; + + toggle = mdb_env_pick_meta(env); + + return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg); +} + +/** Set the default comparison functions for a database. + * Called immediately after a database is opened to set the defaults. + * The user can then override them with #mdb_set_compare() or + * #mdb_set_dupsort(). + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @param[in] dbi A database handle returned by #mdb_open() + */ +static void +mdb_default_cmp(MDB_txn *txn, MDB_dbi dbi) +{ + uint16_t f = txn->mt_dbs[dbi].md_flags; + + txn->mt_dbxs[dbi].md_cmp = + (f & MDB_REVERSEKEY) ? mdb_cmp_memnr : + (f & MDB_INTEGERKEY) ? mdb_cmp_cint : mdb_cmp_memn; + + txn->mt_dbxs[dbi].md_dcmp = + !(f & MDB_DUPSORT) ? 0 : + ((f & MDB_INTEGERDUP) + ? ((f & MDB_DUPFIXED) ? mdb_cmp_int : mdb_cmp_cint) + : ((f & MDB_REVERSEDUP) ? mdb_cmp_memnr : mdb_cmp_memn)); +} + +int mdb_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi) +{ + MDB_val key, data; + MDB_dbi i; + MDB_cursor mc; + int rc, dbflag, exact; + unsigned int unused = 0; + size_t len; + + if (txn->mt_dbxs[FREE_DBI].md_cmp == NULL) { + mdb_default_cmp(txn, FREE_DBI); + } + + /* main DB? */ + if (!name) { + *dbi = MAIN_DBI; + if (flags & (MDB_DUPSORT|MDB_REVERSEKEY|MDB_INTEGERKEY)) + txn->mt_dbs[MAIN_DBI].md_flags |= (flags & (MDB_DUPSORT|MDB_REVERSEKEY|MDB_INTEGERKEY)); + mdb_default_cmp(txn, MAIN_DBI); + return MDB_SUCCESS; + } + + if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) { + mdb_default_cmp(txn, MAIN_DBI); + } + + /* Is the DB already open? */ + len = strlen(name); + for (i=2; imt_numdbs; i++) { + if (!txn->mt_dbxs[i].md_name.mv_size) { + /* Remember this free slot */ + if (!unused) unused = i; + continue; + } + if (len == txn->mt_dbxs[i].md_name.mv_size && + !strncmp(name, txn->mt_dbxs[i].md_name.mv_data, len)) { + *dbi = i; + return MDB_SUCCESS; + } + } + + /* If no free slot and max hit, fail */ + if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs - 1) + return MDB_DBS_FULL; + + /* Find the DB info */ + dbflag = 0; + exact = 0; + key.mv_size = len; + key.mv_data = (void *)name; + mdb_cursor_init(&mc, txn, MAIN_DBI, NULL); + rc = mdb_cursor_set(&mc, &key, &data, MDB_SET, &exact); + if (rc == MDB_SUCCESS) { + /* make sure this is actually a DB */ + MDB_node *node = NODEPTR(mc.mc_pg[mc.mc_top], mc.mc_ki[mc.mc_top]); + if (!(node->mn_flags & F_SUBDATA)) + return EINVAL; + } else if (rc == MDB_NOTFOUND && (flags & MDB_CREATE)) { + /* Create if requested */ + MDB_db dummy; + data.mv_size = sizeof(MDB_db); + data.mv_data = &dummy; + memset(&dummy, 0, sizeof(dummy)); + dummy.md_root = P_INVALID; + dummy.md_flags = flags & 0xffff; + rc = mdb_cursor_put(&mc, &key, &data, F_SUBDATA); + dbflag = DB_DIRTY; + } + + /* OK, got info, add to table */ + if (rc == MDB_SUCCESS) { + unsigned int slot = unused ? unused : txn->mt_numdbs; + txn->mt_dbxs[slot].md_name.mv_data = strdup(name); + txn->mt_dbxs[slot].md_name.mv_size = len; + txn->mt_dbxs[slot].md_rel = NULL; + txn->mt_dbflags[slot] = dbflag; + memcpy(&txn->mt_dbs[slot], data.mv_data, sizeof(MDB_db)); + *dbi = slot; + txn->mt_env->me_dbflags[slot] = txn->mt_dbs[slot].md_flags; + mdb_default_cmp(txn, slot); + if (!unused) { + txn->mt_numdbs++; + txn->mt_env->me_numdbs++; + } + } + + return rc; +} + +int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *arg) +{ + if (txn == NULL || arg == NULL || dbi >= txn->mt_numdbs) + return EINVAL; + + return mdb_stat0(txn->mt_env, &txn->mt_dbs[dbi], arg); +} + +void mdb_close(MDB_env *env, MDB_dbi dbi) +{ + char *ptr; + if (dbi <= MAIN_DBI || dbi >= env->me_numdbs) + return; + ptr = env->me_dbxs[dbi].md_name.mv_data; + env->me_dbxs[dbi].md_name.mv_data = NULL; + env->me_dbxs[dbi].md_name.mv_size = 0; + free(ptr); +} + +/** Add all the DB's pages to the free list. + * @param[in] mc Cursor on the DB to free. + * @param[in] subs non-Zero to check for sub-DBs in this DB. + * @return 0 on success, non-zero on failure. + */ +static int +mdb_drop0(MDB_cursor *mc, int subs) +{ + int rc; + + rc = mdb_page_search(mc, NULL, 0); + if (rc == MDB_SUCCESS) { + MDB_node *ni; + MDB_cursor mx; + unsigned int i; + + /* LEAF2 pages have no nodes, cannot have sub-DBs */ + if (!subs || IS_LEAF2(mc->mc_pg[mc->mc_top])) + mdb_cursor_pop(mc); + + mdb_cursor_copy(mc, &mx); + while (mc->mc_snum > 0) { + if (IS_LEAF(mc->mc_pg[mc->mc_top])) { + for (i=0; imc_pg[mc->mc_top]); i++) { + ni = NODEPTR(mc->mc_pg[mc->mc_top], i); + if (ni->mn_flags & F_SUBDATA) { + mdb_xcursor_init1(mc, ni); + rc = mdb_drop0(&mc->mc_xcursor->mx_cursor, 0); + if (rc) + return rc; + } + } + } else { + for (i=0; imc_pg[mc->mc_top]); i++) { + pgno_t pg; + ni = NODEPTR(mc->mc_pg[mc->mc_top], i); + pg = NODEPGNO(ni); + /* free it */ + mdb_midl_append(&mc->mc_txn->mt_free_pgs, pg); + } + } + if (!mc->mc_top) + break; + rc = mdb_cursor_sibling(mc, 1); + if (rc) { + /* no more siblings, go back to beginning + * of previous level. (stack was already popped + * by mdb_cursor_sibling) + */ + for (i=1; imc_top; i++) + mc->mc_pg[i] = mx.mc_pg[i]; + } + } + /* free it */ + mdb_midl_append(&mc->mc_txn->mt_free_pgs, + mc->mc_db->md_root); + } + return 0; +} + +int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del) +{ + MDB_cursor *mc; + int rc; + + if (!txn || !dbi || dbi >= txn->mt_numdbs) + return EINVAL; + + if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) + return EACCES; + + rc = mdb_cursor_open(txn, dbi, &mc); + if (rc) + return rc; + + rc = mdb_drop0(mc, mc->mc_db->md_flags & MDB_DUPSORT); + if (rc) + goto leave; + + /* Can't delete the main DB */ + if (del && dbi > MAIN_DBI) { + rc = mdb_del(txn, MAIN_DBI, &mc->mc_dbx->md_name, NULL); + if (!rc) + mdb_close(txn->mt_env, dbi); + } else { + /* reset the DB record, mark it dirty */ + txn->mt_dbflags[dbi] |= DB_DIRTY; + txn->mt_dbs[dbi].md_depth = 0; + txn->mt_dbs[dbi].md_branch_pages = 0; + txn->mt_dbs[dbi].md_leaf_pages = 0; + txn->mt_dbs[dbi].md_overflow_pages = 0; + txn->mt_dbs[dbi].md_entries = 0; + txn->mt_dbs[dbi].md_root = P_INVALID; + + if (!txn->mt_u.dirty_list[0].mid) { + MDB_cursor m2; + MDB_val key, data; + /* make sure we have at least one dirty page in this txn + * otherwise these changes will be ignored. + */ + key.mv_size = sizeof(txnid_t); + key.mv_data = &txn->mt_txnid; + data.mv_size = sizeof(MDB_ID); + data.mv_data = txn->mt_free_pgs; + mdb_cursor_init(&m2, txn, FREE_DBI, NULL); + rc = mdb_cursor_put(&m2, &key, &data, 0); + } + } +leave: + mdb_cursor_close(mc); + return rc; +} + +int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp) +{ + if (txn == NULL || !dbi || dbi >= txn->mt_numdbs) + return EINVAL; + + txn->mt_dbxs[dbi].md_cmp = cmp; + return MDB_SUCCESS; +} + +int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp) +{ + if (txn == NULL || !dbi || dbi >= txn->mt_numdbs) + return EINVAL; + + txn->mt_dbxs[dbi].md_dcmp = cmp; + return MDB_SUCCESS; +} + +int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel) +{ + if (txn == NULL || !dbi || dbi >= txn->mt_numdbs) + return EINVAL; + + txn->mt_dbxs[dbi].md_rel = rel; + return MDB_SUCCESS; +} + +int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx) +{ + if (txn == NULL || !dbi || dbi >= txn->mt_numdbs) + return EINVAL; + + txn->mt_dbxs[dbi].md_relctx = ctx; + return MDB_SUCCESS; +} + +/** @} */ diff --git a/c_src/mdb.h b/c_src/mdb.h new file mode 100644 index 0000000..925bf17 --- /dev/null +++ b/c_src/mdb.h @@ -0,0 +1,1065 @@ +/** @file mdb.h + * @brief memory-mapped database library + * + * @mainpage MDB Memory-Mapped Database Manager + * MDB is a Btree-based database management library modeled loosely on the + * BerkeleyDB API, but much simplified. The entire database is exposed + * in a memory map, and all data fetches return data directly + * from the mapped memory, so no malloc's or memcpy's occur during + * data fetches. As such, the library is extremely simple because it + * requires no page caching layer of its own, and it is extremely high + * performance and memory-efficient. It is also fully transactional with + * full ACID semantics, and when the memory map is read-only, the + * database integrity cannot be corrupted by stray pointer writes from + * application code. + * + * The library is fully thread-aware and supports concurrent read/write + * access from multiple processes and threads. Data pages use a copy-on- + * write strategy so no active data pages are ever overwritten, which + * also provides resistance to corruption and eliminates the need of any + * special recovery procedures after a system crash. Writes are fully + * serialized; only one write transaction may be active at a time, which + * guarantees that writers can never deadlock. The database structure is + * multi-versioned so readers run with no locks; writers cannot block + * readers, and readers don't block writers. + * + * Unlike other well-known database mechanisms which use either write-ahead + * transaction logs or append-only data writes, MDB requires no maintenance + * during operation. Both write-ahead loggers and append-only databases + * require periodic checkpointing and/or compaction of their log or database + * files otherwise they grow without bound. MDB tracks free pages within + * the database and re-uses them for new write operations, so the database + * size does not grow without bound in normal use. + * + * The memory map can be used as a read-only or read-write map. It is + * read-only by default as this provides total immunity to corruption. + * Using read-write mode offers much higher write performance, but adds + * the possibility for stray application writes thru pointers to silently + * corrupt the database. Of course if your application code is known to + * be bug-free (...) then this is not an issue. + * + * @author Howard Chu, Symas Corporation. + * + * @copyright Copyright 2011-2012 Howard Chu, Symas Corp. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted only as authorized by the OpenLDAP + * Public License. + * + * A copy of this license is available in the file LICENSE in the + * top-level directory of the distribution or, alternatively, at + * . + * + * @par Derived From: + * This code is derived from btree.c written by Martin Hedenfalk. + * + * Copyright (c) 2009, 2010 Martin Hedenfalk + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ +#ifndef _MDB_H_ +#define _MDB_H_ + +#include + +#ifdef __cplusplus +extern "C" { +#endif + +/** @defgroup public Public API + * @{ + */ +/** @defgroup Version Version Macros + * @{ + */ +/** Library major version */ +#define MDB_VERSION_MAJOR 0 +/** Library minor version */ +#define MDB_VERSION_MINOR 9 +/** Library patch version */ +#define MDB_VERSION_PATCH 4 + +/** Combine args a,b,c into a single integer for easy version comparisons */ +#define MDB_VERINT(a,b,c) (((a) << 24) | ((b) << 16) | (c)) + +/** The full library version as a single integer */ +#define MDB_VERSION_FULL \ + MDB_VERINT(MDB_VERSION_MAJOR,MDB_VERSION_MINOR,MDB_VERSION_PATCH) + +/** The release date of this library version */ +#define MDB_VERSION_DATE "September 14, 2012" + +/** A stringifier for the version info */ +#define MDB_VERSTR(a,b,c,d) "MDB " #a "." #b "." #c ": (" d ")" + +/** A helper for the stringifier macro */ +#define MDB_VERFOO(a,b,c,d) MDB_VERSTR(a,b,c,d) + +/** The full library version as a C string */ +#define MDB_VERSION_STRING \ + MDB_VERFOO(MDB_VERSION_MAJOR,MDB_VERSION_MINOR,MDB_VERSION_PATCH,MDB_VERSION_DATE) +/** @} */ + +/** @brief Opaque structure for a database environment. + * + * A DB environment supports multiple databases, all residing in the same + * shared-memory map. + */ +typedef struct MDB_env MDB_env; + +/** @brief Opaque structure for a transaction handle. + * + * All database operations require a transaction handle. Transactions may be + * read-only or read-write. + */ +typedef struct MDB_txn MDB_txn; + +/** @brief A handle for an individual database in the DB environment. */ +typedef unsigned int MDB_dbi; + +/** @brief Opaque structure for navigating through a database */ +typedef struct MDB_cursor MDB_cursor; + +/** @brief Generic structure used for passing keys and data in and out of the database. */ +typedef struct MDB_val { + size_t mv_size; /**< size of the data item */ + void *mv_data; /**< address of the data item */ +} MDB_val; + +/** @brief A callback function used to compare two keys in a database */ +typedef int (MDB_cmp_func)(const MDB_val *a, const MDB_val *b); + +/** @brief A callback function used to relocate a position-dependent data item + * in a fixed-address database. + * + * The \b newptr gives the item's desired address in + * the memory map, and \b oldptr gives its previous address. The item's actual + * data resides at the address in \b item. This callback is expected to walk + * through the fields of the record in \b item and modify any + * values based at the \b oldptr address to be relative to the \b newptr address. + * @param[in,out] item The item that is to be relocated. + * @param[in] oldptr The previous address. + * @param[in] newptr The new address to relocate to. + * @param[in] relctx An application-provided context, set by #mdb_set_relctx(). + * @todo This feature is currently unimplemented. + */ +typedef void (MDB_rel_func)(MDB_val *item, void *oldptr, void *newptr, void *relctx); + +/** @defgroup mdb_env Environment Flags + * @{ + */ + /** mmap at a fixed address */ +#define MDB_FIXEDMAP 0x01 + /** no environment directory */ +#define MDB_NOSUBDIR 0x02 + /** don't fsync after commit */ +#define MDB_NOSYNC 0x10000 + /** read only */ +#define MDB_RDONLY 0x20000 + /** don't fsync metapage after commit */ +#define MDB_NOMETASYNC 0x40000 + /** use writable mmap */ +#define MDB_WRITEMAP 0x80000 + /** use asynchronous msync */ +#define MDB_MAPASYNC 0x100000 +/** @} */ + +/** @defgroup mdb_open Database Flags + * @{ + */ + /** use reverse string keys */ +#define MDB_REVERSEKEY 0x02 + /** use sorted duplicates */ +#define MDB_DUPSORT 0x04 + /** numeric keys in native byte order. + * The keys must all be of the same size. */ +#define MDB_INTEGERKEY 0x08 + /** with #MDB_DUPSORT, sorted dup items have fixed size */ +#define MDB_DUPFIXED 0x10 + /** with #MDB_DUPSORT, dups are numeric in native byte order */ +#define MDB_INTEGERDUP 0x20 + /** with #MDB_DUPSORT, use reverse string dups */ +#define MDB_REVERSEDUP 0x40 + /** create DB if not already existing */ +#define MDB_CREATE 0x40000 +/** @} */ + +/** @defgroup mdb_put Write Flags + * @{ + */ +/** For put: Don't write if the key already exists. */ +#define MDB_NOOVERWRITE 0x10 +/** Only for #MDB_DUPSORT
+ * For put: don't write if the key and data pair already exist.
+ * For mdb_cursor_del: remove all duplicate data items. + */ +#define MDB_NODUPDATA 0x20 +/** For mdb_cursor_put: overwrite the current key/data pair */ +#define MDB_CURRENT 0x40 +/** For put: Just reserve space for data, don't copy it. Return a + * pointer to the reserved space. + */ +#define MDB_RESERVE 0x10000 +/** Data is being appended, don't split full pages. */ +#define MDB_APPEND 0x20000 +/** Duplicate data is being appended, don't split full pages. */ +#define MDB_APPENDDUP 0x40000 +/** Store multiple data items in one call. */ +#define MDB_MULTIPLE 0x80000 +/* @} */ + +/** @brief Cursor Get operations. + * + * This is the set of all operations for retrieving data + * using a cursor. + */ +typedef enum MDB_cursor_op { + MDB_FIRST, /**< Position at first key/data item */ + MDB_FIRST_DUP, /**< Position at first data item of current key. + Only for #MDB_DUPSORT */ + MDB_GET_BOTH, /**< Position at key/data pair. Only for #MDB_DUPSORT */ + MDB_GET_BOTH_RANGE, /**< position at key, nearest data. Only for #MDB_DUPSORT */ + MDB_GET_CURRENT, /**< Return key/data at current cursor position */ + MDB_GET_MULTIPLE, /**< Return all the duplicate data items at the current + cursor position. Only for #MDB_DUPFIXED */ + MDB_LAST, /**< Position at last key/data item */ + MDB_LAST_DUP, /**< Position at last data item of current key. + Only for #MDB_DUPSORT */ + MDB_NEXT, /**< Position at next data item */ + MDB_NEXT_DUP, /**< Position at next data item of current key. + Only for #MDB_DUPSORT */ + MDB_NEXT_MULTIPLE, /**< Return all duplicate data items at the next + cursor position. Only for #MDB_DUPFIXED */ + MDB_NEXT_NODUP, /**< Position at first data item of next key. + Only for #MDB_DUPSORT */ + MDB_PREV, /**< Position at previous data item */ + MDB_PREV_DUP, /**< Position at previous data item of current key. + Only for #MDB_DUPSORT */ + MDB_PREV_NODUP, /**< Position at last data item of previous key. + Only for #MDB_DUPSORT */ + MDB_SET, /**< Position at specified key */ + MDB_SET_KEY, /**< Position at specified key, return key + data */ + MDB_SET_RANGE /**< Position at first key greater than or equal to specified key. */ +} MDB_cursor_op; + +/** @defgroup errors Return Codes + * + * BerkeleyDB uses -30800 to -30999, we'll go under them + * @{ + */ + /** Successful result */ +#define MDB_SUCCESS 0 + /** key/data pair already exists */ +#define MDB_KEYEXIST (-30799) + /** key/data pair not found (EOF) */ +#define MDB_NOTFOUND (-30798) + /** Requested page not found - this usually indicates corruption */ +#define MDB_PAGE_NOTFOUND (-30797) + /** Located page was wrong type */ +#define MDB_CORRUPTED (-30796) + /** Update of meta page failed, probably I/O error */ +#define MDB_PANIC (-30795) + /** Environment version mismatch */ +#define MDB_VERSION_MISMATCH (-30794) + /** File is not a valid MDB file */ +#define MDB_INVALID (-30793) + /** Environment mapsize reached */ +#define MDB_MAP_FULL (-30792) + /** Environment maxdbs reached */ +#define MDB_DBS_FULL (-30791) + /** Environment maxreaders reached */ +#define MDB_READERS_FULL (-30790) + /** Too many TLS keys in use - Windows only */ +#define MDB_TLS_FULL (-30789) + /** Nested txn has too many dirty pages */ +#define MDB_TXN_FULL (-30788) + /** Cursor stack too deep - internal error */ +#define MDB_CURSOR_FULL (-30787) + /** Page has not enough space - internal error */ +#define MDB_PAGE_FULL (-30786) +#define MDB_LAST_ERRCODE MDB_PAGE_FULL +/** @} */ + +/** @brief Statistics for a database in the environment */ +typedef struct MDB_stat { + unsigned int ms_psize; /**< Size of a database page. + This is currently the same for all databases. */ + unsigned int ms_depth; /**< Depth (height) of the B-tree */ + size_t ms_branch_pages; /**< Number of internal (non-leaf) pages */ + size_t ms_leaf_pages; /**< Number of leaf pages */ + size_t ms_overflow_pages; /**< Number of overflow pages */ + size_t ms_entries; /**< Number of data items */ +} MDB_stat; + + /** @brief Return the mdb library version information. + * + * @param[out] major if non-NULL, the library major version number is copied here + * @param[out] minor if non-NULL, the library minor version number is copied here + * @param[out] patch if non-NULL, the library patch version number is copied here + * @retval "version string" The library version as a string + */ +char *mdb_version(int *major, int *minor, int *patch); + + /** @brief Return a string describing a given error code. + * + * This function is a superset of the ANSI C X3.159-1989 (ANSI C) strerror(3) + * function. If the error code is greater than or equal to 0, then the string + * returned by the system function strerror(3) is returned. If the error code + * is less than 0, an error string corresponding to the MDB library error is + * returned. See @ref errors for a list of MDB-specific error codes. + * @param[in] err The error code + * @retval "error message" The description of the error + */ +char *mdb_strerror(int err); + + /** @brief Create an MDB environment handle. + * + * This function allocates memory for a #MDB_env structure. To release + * the allocated memory and discard the handle, call #mdb_env_close(). + * Before the handle may be used, it must be opened using #mdb_env_open(). + * Various other options may also need to be set before opening the handle, + * e.g. #mdb_env_set_mapsize(), #mdb_env_set_maxreaders(), #mdb_env_set_maxdbs(), + * depending on usage requirements. + * @param[out] env The address where the new handle will be stored + * @return A non-zero error value on failure and 0 on success. + */ +int mdb_env_create(MDB_env **env); + + /** @brief Open an environment handle. + * + * If this function fails, #mdb_env_close() must be called to discard the #MDB_env handle. + * @param[in] env An environment handle returned by #mdb_env_create() + * @param[in] path The directory in which the database files reside. This + * directory must already exist and be writable. + * @param[in] flags Special options for this environment. This parameter + * must be set to 0 or by bitwise OR'ing together one or more of the + * values described here. + *
    + *
  • #MDB_FIXEDMAP + * use a fixed address for the mmap region. This flag must be specified + * when creating the environment, and is stored persistently in the environment. + * If successful, the memory map will always reside at the same virtual address + * and pointers used to reference data items in the database will be constant + * across multiple invocations. This option may not always work, depending on + * how the operating system has allocated memory to shared libraries and other uses. + * The feature is highly experimental. + *
  • #MDB_NOSUBDIR + * By default, MDB creates its environment in a directory whose + * pathname is given in \b path, and creates its data and lock files + * under that directory. With this option, \b path is used as-is for + * the database main data file. The database lock file is the \b path + * with "-lock" appended. + *
  • #MDB_NOSYNC + * Don't perform a synchronous flush after committing a transaction. This means + * transactions will exhibit the ACI (atomicity, consistency, and isolation) + * properties, but not D (durability); that is database integrity will be + * maintained but it is possible some number of the most recently committed + * transactions may be undone after a system crash. The number of transactions + * at risk is governed by how often the system flushes dirty buffers to disk + * and how often #mdb_env_sync() is called. This flag may be changed + * at any time using #mdb_env_set_flags(). + *
  • #MDB_NOMETASYNC + * Don't perform a synchronous flush of the meta page after committing + * a transaction. This is similar to the #MDB_NOSYNC case, but safer + * because the transaction data is still flushed. The meta page for any + * transaction N will be flushed by the data flush of transaction N+1. + * In case of a system crash, the last committed transaction may be + * lost. This flag may be changed at any time using #mdb_env_set_flags(). + *
  • #MDB_RDONLY + * Open the environment in read-only mode. No write operations will be allowed. + *
+ * @param[in] mode The UNIX permissions to set on created files. This parameter + * is ignored on Windows. + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • #MDB_VERSION_MISMATCH - the version of the MDB library doesn't match the + * version that created the database environment. + *
  • EINVAL - the environment file headers are corrupted. + *
  • ENOENT - the directory specified by the path parameter doesn't exist. + *
  • EACCES - the user didn't have permission to access the environment files. + *
  • EAGAIN - the environment was locked by another process. + *
+ */ +int mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode); + + /** @brief Return statistics about the MDB environment. + * + * @param[in] env An environment handle returned by #mdb_env_create() + * @param[out] stat The address of an #MDB_stat structure + * where the statistics will be copied + */ +int mdb_env_stat(MDB_env *env, MDB_stat *stat); + + /** @brief Flush the data buffers to disk. + * + * Data is always written to disk when #mdb_txn_commit() is called, + * but the operating system may keep it buffered. MDB always flushes + * the OS buffers upon commit as well, unless the environment was + * opened with #MDB_NOSYNC. + * @param[in] env An environment handle returned by #mdb_env_create() + * @param[in] force If non-zero, force the flush to occur. Otherwise + * if the environment has the #MDB_NOSYNC flag set the flushes + * will be omitted. + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
  • EIO - an error occurred during synchronization. + *
+ */ +int mdb_env_sync(MDB_env *env, int force); + + /** @brief Close the environment and release the memory map. + * + * Only a single thread may call this function. All transactions, databases, + * and cursors must already be closed before calling this function. Attempts to + * use any such handles after calling this function will cause a SIGSEGV. + * The environment handle will be freed and must not be used again after this call. + * @param[in] env An environment handle returned by #mdb_env_create() + */ +void mdb_env_close(MDB_env *env); + + /** @brief Set environment flags. + * + * This may be used to set some flags that weren't already set during + * #mdb_env_open(), or to unset these flags. + * @param[in] env An environment handle returned by #mdb_env_create() + * @param[in] flags The flags to change, bitwise OR'ed together + * @param[in] onoff A non-zero value sets the flags, zero clears them. + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_env_set_flags(MDB_env *env, unsigned int flags, int onoff); + + /** @brief Get environment flags. + * + * @param[in] env An environment handle returned by #mdb_env_create() + * @param[out] flags The address of an integer to store the flags + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_env_get_flags(MDB_env *env, unsigned int *flags); + + /** @brief Return the path that was used in #mdb_env_open(). + * + * @param[in] env An environment handle returned by #mdb_env_create() + * @param[out] path Address of a string pointer to contain the path. This + * is the actual string in the environment, not a copy. It should not be + * altered in any way. + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_env_get_path(MDB_env *env, const char **path); + + /** @brief Set the size of the memory map to use for this environment. + * + * The size should be a multiple of the OS page size. The default is + * 10485760 bytes. The size of the memory map is also the maximum size + * of the database. The value should be chosen as large as possible, + * to accommodate future growth of the database. + * This function may only be called after #mdb_env_create() and before #mdb_env_open(). + * @param[in] env An environment handle returned by #mdb_env_create() + * @param[in] size The size in bytes + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - an invalid parameter was specified, or the environment is already open. + *
+ */ +int mdb_env_set_mapsize(MDB_env *env, size_t size); + + /** @brief Set the maximum number of threads for the environment. + * + * This defines the number of slots in the lock table that is used to track readers in the + * the environment. The default is 126. + * This function may only be called after #mdb_env_create() and before #mdb_env_open(). + * @param[in] env An environment handle returned by #mdb_env_create() + * @param[in] readers The maximum number of threads + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - an invalid parameter was specified, or the environment is already open. + *
+ */ +int mdb_env_set_maxreaders(MDB_env *env, unsigned int readers); + + /** @brief Get the maximum number of threads for the environment. + * + * @param[in] env An environment handle returned by #mdb_env_create() + * @param[out] readers Address of an integer to store the number of readers + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers); + + /** @brief Set the maximum number of databases for the environment. + * + * This function is only needed if multiple databases will be used in the + * environment. Simpler applications that only use a single database can ignore + * this option. + * This function may only be called after #mdb_env_create() and before #mdb_env_open(). + * @param[in] env An environment handle returned by #mdb_env_create() + * @param[in] dbs The maximum number of databases + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - an invalid parameter was specified, or the environment is already open. + *
+ */ +int mdb_env_set_maxdbs(MDB_env *env, MDB_dbi dbs); + + /** @brief Create a transaction for use with the environment. + * + * The transaction handle may be discarded using #mdb_txn_abort() or #mdb_txn_commit(). + * @note Transactions may not span threads; a transaction must only be used by a + * single thread. Also, a thread may only have a single transaction. + * @note Cursors may not span transactions; each cursor must be opened and closed + * within a single transaction. + * @param[in] env An environment handle returned by #mdb_env_create() + * @param[in] parent If this parameter is non-NULL, the new transaction + * will be a nested transaction, with the transaction indicated by \b parent + * as its parent. Transactions may be nested to any level. A parent + * transaction may not issue any other operations besides mdb_txn_begin, + * mdb_txn_abort, or mdb_txn_commit while it has active child transactions. + * @param[in] flags Special options for this transaction. This parameter + * must be set to 0 or by bitwise OR'ing together one or more of the + * values described here. + *
    + *
  • #MDB_RDONLY + * This transaction will not perform any write operations. + *
+ * @param[out] txn Address where the new #MDB_txn handle will be stored + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • #MDB_PANIC - a fatal error occurred earlier and the environment + * must be shut down. + *
  • ENOMEM - out of memory, or a read-only transaction was requested and + * the reader lock table is full. See #mdb_env_set_maxreaders(). + *
+ */ +int mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned int flags, MDB_txn **txn); + + /** @brief Commit all the operations of a transaction into the database. + * + * All cursors opened within the transaction will be closed by this call. The cursors + * and transaction handle will be freed and must not be used again after this call. + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
  • ENOSPC - no more disk space. + *
  • EIO - a low-level I/O error occurred while writing. + *
  • ENOMEM - the transaction is nested and could not be merged into its parent. + *
+ */ +int mdb_txn_commit(MDB_txn *txn); + + /** @brief Abandon all the operations of the transaction instead of saving them. + * + * All cursors opened within the transaction will be closed by this call. The cursors + * and transaction handle will be freed and must not be used again after this call. + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + */ +void mdb_txn_abort(MDB_txn *txn); + + /** @brief Reset a read-only transaction. + * + * This releases the current reader lock but doesn't free the + * transaction handle, allowing it to be used again later by #mdb_txn_renew(). + * It otherwise has the same effect as #mdb_txn_abort() but saves some memory + * allocation/deallocation overhead if a thread is going to start a new + * read-only transaction again soon. + * All cursors opened within the transaction must be closed before the transaction + * is reset. + * Reader locks generally don't interfere with writers, but they keep old + * versions of database pages allocated. Thus they prevent the old pages + * from being reused when writers commit new data, and so under heavy load + * the database size may grow much more rapidly than otherwise. + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + */ +void mdb_txn_reset(MDB_txn *txn); + + /** @brief Renew a read-only transaction. + * + * This acquires a new reader lock for a transaction handle that had been + * released by #mdb_txn_reset(). It must be called before a reset transaction + * may be used again. + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • #MDB_PANIC - a fatal error occurred earlier and the environment + * must be shut down. + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_txn_renew(MDB_txn *txn); + + /** @brief Open a database in the environment. + * + * The database handle may be discarded by calling #mdb_close(). The + * database handle resides in the shared environment, it is not owned + * by the given transaction. Only one thread should call this function; + * it is not mutex-protected in a read-only transaction. + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @param[in] name The name of the database to open. If only a single + * database is needed in the environment, this value may be NULL. + * @param[in] flags Special options for this database. This parameter + * must be set to 0 or by bitwise OR'ing together one or more of the + * values described here. + *
    + *
  • #MDB_REVERSEKEY + * Keys are strings to be compared in reverse order, from the end + * of the strings to the beginning. By default, Keys are treated as strings and + * compared from beginning to end. + *
  • #MDB_DUPSORT + * Duplicate keys may be used in the database. (Or, from another perspective, + * keys may have multiple data items, stored in sorted order.) By default + * keys must be unique and may have only a single data item. + *
  • #MDB_INTEGERKEY + * Keys are binary integers in native byte order. Setting this option + * requires all keys to be the same size, typically sizeof(int) + * or sizeof(size_t). + *
  • #MDB_DUPFIXED + * This flag may only be used in combination with #MDB_DUPSORT. This option + * tells the library that the data items for this database are all the same + * size, which allows further optimizations in storage and retrieval. When + * all data items are the same size, the #MDB_GET_MULTIPLE and #MDB_NEXT_MULTIPLE + * cursor operations may be used to retrieve multiple items at once. + *
  • #MDB_INTEGERDUP + * This option specifies that duplicate data items are also integers, and + * should be sorted as such. + *
  • #MDB_REVERSEDUP + * This option specifies that duplicate data items should be compared as + * strings in reverse order. + *
  • #MDB_CREATE + * Create the named database if it doesn't exist. This option is not + * allowed in a read-only transaction or a read-only environment. + *
+ * @param[out] dbi Address where the new #MDB_dbi handle will be stored + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • #MDB_NOTFOUND - the specified database doesn't exist in the environment + * and #MDB_CREATE was not specified. + *
  • ENFILE - too many databases have been opened. See #mdb_env_set_maxdbs(). + *
+ */ +int mdb_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi); + + /** @brief Retrieve statistics for a database. + * + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @param[in] dbi A database handle returned by #mdb_open() + * @param[out] stat The address of an #MDB_stat structure + * where the statistics will be copied + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_stat(MDB_txn *txn, MDB_dbi dbi, MDB_stat *stat); + + /** @brief Close a database handle. + * + * This call is not mutex protected. Handles should only be closed by + * a single thread, and only if no other threads are going to reference + * the database handle any further. + * @param[in] env An environment handle returned by #mdb_env_create() + * @param[in] dbi A database handle returned by #mdb_open() + */ +void mdb_close(MDB_env *env, MDB_dbi dbi); + + /** @brief Delete a database and/or free all its pages. + * + * If the \b del parameter is non-zero the DB handle will be closed + * and the DB will be deleted. + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @param[in] dbi A database handle returned by #mdb_open() + * @param[in] del non-zero to delete the DB from the environment, + * otherwise just free its pages. + * @return A non-zero error value on failure and 0 on success. + */ +int mdb_drop(MDB_txn *txn, MDB_dbi dbi, int del); + + /** @brief Set a custom key comparison function for a database. + * + * The comparison function is called whenever it is necessary to compare a + * key specified by the application with a key currently stored in the database. + * If no comparison function is specified, and no special key flags were specified + * with #mdb_open(), the keys are compared lexically, with shorter keys collating + * before longer keys. + * @warning This function must be called before any data access functions are used, + * otherwise data corruption may occur. The same comparison function must be used by every + * program accessing the database, every time the database is used. + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @param[in] dbi A database handle returned by #mdb_open() + * @param[in] cmp A #MDB_cmp_func function + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_set_compare(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp); + + /** @brief Set a custom data comparison function for a #MDB_DUPSORT database. + * + * This comparison function is called whenever it is necessary to compare a data + * item specified by the application with a data item currently stored in the database. + * This function only takes effect if the database was opened with the #MDB_DUPSORT + * flag. + * If no comparison function is specified, and no special key flags were specified + * with #mdb_open(), the data items are compared lexically, with shorter items collating + * before longer items. + * @warning This function must be called before any data access functions are used, + * otherwise data corruption may occur. The same comparison function must be used by every + * program accessing the database, every time the database is used. + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @param[in] dbi A database handle returned by #mdb_open() + * @param[in] cmp A #MDB_cmp_func function + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_set_dupsort(MDB_txn *txn, MDB_dbi dbi, MDB_cmp_func *cmp); + + /** @brief Set a relocation function for a #MDB_FIXEDMAP database. + * + * @todo The relocation function is called whenever it is necessary to move the data + * of an item to a different position in the database (e.g. through tree + * balancing operations, shifts as a result of adds or deletes, etc.). It is + * intended to allow address/position-dependent data items to be stored in + * a database in an environment opened with the #MDB_FIXEDMAP option. + * Currently the relocation feature is unimplemented and setting + * this function has no effect. + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @param[in] dbi A database handle returned by #mdb_open() + * @param[in] rel A #MDB_rel_func function + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_set_relfunc(MDB_txn *txn, MDB_dbi dbi, MDB_rel_func *rel); + + /** @brief Set a context pointer for a #MDB_FIXEDMAP database's relocation function. + * + * See #mdb_set_relfunc and #MDB_rel_func for more details. + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @param[in] dbi A database handle returned by #mdb_open() + * @param[in] ctx An arbitrary pointer for whatever the application needs. + * It will be passed to the callback function set by #mdb_set_relfunc + * as its \b relctx parameter whenever the callback is invoked. + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_set_relctx(MDB_txn *txn, MDB_dbi dbi, void *ctx); + + /** @brief Get items from a database. + * + * This function retrieves key/data pairs from the database. The address + * and length of the data associated with the specified \b key are returned + * in the structure to which \b data refers. + * If the database supports duplicate keys (#MDB_DUPSORT) then the + * first data item for the key will be returned. Retrieval of other + * items requires the use of #mdb_cursor_get(). + * + * @note The memory pointed to by the returned values is owned by the + * database. The caller need not dispose of the memory, and may not + * modify it in any way. For values returned in a read-only transaction + * any modification attempts will cause a SIGSEGV. + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @param[in] dbi A database handle returned by #mdb_open() + * @param[in] key The key to search for in the database + * @param[out] data The data corresponding to the key + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • #MDB_NOTFOUND - the key was not in the database. + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_get(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data); + + /** @brief Store items into a database. + * + * This function stores key/data pairs in the database. The default behavior + * is to enter the new key/data pair, replacing any previously existing key + * if duplicates are disallowed, or adding a duplicate data item if + * duplicates are allowed (#MDB_DUPSORT). + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @param[in] dbi A database handle returned by #mdb_open() + * @param[in] key The key to store in the database + * @param[in,out] data The data to store + * @param[in] flags Special options for this operation. This parameter + * must be set to 0 or by bitwise OR'ing together one or more of the + * values described here. + *
    + *
  • #MDB_NODUPDATA - enter the new key/data pair only if it does not + * already appear in the database. This flag may only be specified + * if the database was opened with #MDB_DUPSORT. The function will + * return #MDB_KEYEXIST if the key/data pair already appears in the + * database. + *
  • #MDB_NOOVERWRITE - enter the new key/data pair only if the key + * does not already appear in the database. The function will return + * #MDB_KEYEXIST if the key already appears in the database, even if + * the database supports duplicates (#MDB_DUPSORT). The \b data + * parameter will be set to point to the existing item. + *
  • #MDB_RESERVE - reserve space for data of the given size, but + * don't copy the given data. Instead, return a pointer to the + * reserved space, which the caller can fill in later. This saves + * an extra memcpy if the data is being generated later. + *
  • #MDB_APPEND - append the given key/data pair to the end of the + * database. No key comparisons are performed. This option allows + * fast bulk loading when keys are already known to be in the + * correct order. Loading unsorted keys with this flag will cause + * data corruption. + *
  • #MDB_APPENDDUP - as above, but for sorted dup data. + *
+ * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EACCES - an attempt was made to write in a read-only transaction. + *
  • EINVAL - an invalid parameter was specified. + *
  • ENOMEM - the database is full, see #mdb_env_set_mapsize(). + *
+ */ +int mdb_put(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data, + unsigned int flags); + + /** @brief Delete items from a database. + * + * This function removes key/data pairs from the database. + * If the database does not support sorted duplicate data items + * (#MDB_DUPSORT) the data parameter is ignored. + * If the database supports sorted duplicates and the data parameter + * is NULL, all of the duplicate data items for the key will be + * deleted. Otherwise, if the data parameter is non-NULL + * only the matching data item will be deleted. + * This function will return #MDB_NOTFOUND if the specified key/data + * pair is not in the database. + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @param[in] dbi A database handle returned by #mdb_open() + * @param[in] key The key to delete from the database + * @param[in] data The data to delete + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EACCES - an attempt was made to write in a read-only transaction. + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_del(MDB_txn *txn, MDB_dbi dbi, MDB_val *key, MDB_val *data); + + /** @brief Create a cursor handle. + * + * Cursors are associated with a specific transaction and database and + * may not span threads. + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @param[in] dbi A database handle returned by #mdb_open() + * @param[out] cursor Address where the new #MDB_cursor handle will be stored + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_cursor_open(MDB_txn *txn, MDB_dbi dbi, MDB_cursor **cursor); + + /** @brief Close a cursor handle. + * + * The cursor handle will be freed and must not be used again after this call. + * @param[in] cursor A cursor handle returned by #mdb_cursor_open() + */ +void mdb_cursor_close(MDB_cursor *cursor); + + /** @brief Renew a cursor handle. + * + * Cursors are associated with a specific transaction and database and + * may not span threads. Cursors that are only used in read-only + * transactions may be re-used, to avoid unnecessary malloc/free overhead. + * The cursor may be associated with a new read-only transaction, and + * referencing the same database handle as it was created with. + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @param[in] cursor A cursor handle returned by #mdb_cursor_open() + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_cursor_renew(MDB_txn *txn, MDB_cursor *cursor); + + /** @brief Return the cursor's transaction handle. + * + * @param[in] cursor A cursor handle returned by #mdb_cursor_open() + */ +MDB_txn *mdb_cursor_txn(MDB_cursor *cursor); + + /** @brief Return the cursor's database handle. + * + * @param[in] cursor A cursor handle returned by #mdb_cursor_open() + */ +MDB_dbi mdb_cursor_dbi(MDB_cursor *cursor); + + /** @brief Retrieve by cursor. + * + * This function retrieves key/data pairs from the database. The address and length + * of the key are returned in the object to which \b key refers (except for the + * case of the #MDB_SET option, in which the \b key object is unchanged), and + * the address and length of the data are returned in the object to which \b data + * refers. + * @param[in] cursor A cursor handle returned by #mdb_cursor_open() + * @param[in,out] key The key for a retrieved item + * @param[in,out] data The data of a retrieved item + * @param[in] op A cursor operation #MDB_cursor_op + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • #MDB_NOTFOUND - no matching key found. + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_cursor_get(MDB_cursor *cursor, MDB_val *key, MDB_val *data, + MDB_cursor_op op); + + /** @brief Store by cursor. + * + * This function stores key/data pairs into the database. + * If the function fails for any reason, the state of the cursor will be + * unchanged. If the function succeeds and an item is inserted into the + * database, the cursor is always positioned to refer to the newly inserted item. + * @param[in] cursor A cursor handle returned by #mdb_cursor_open() + * @param[in] key The key operated on. + * @param[in] data The data operated on. + * @param[in] flags Options for this operation. This parameter + * must be set to 0 or one of the values described here. + *
    + *
  • #MDB_CURRENT - overwrite the data of the key/data pair to which + * the cursor refers with the specified data item. The \b key + * parameter is ignored. + *
  • #MDB_NODUPDATA - enter the new key/data pair only if it does not + * already appear in the database. This flag may only be specified + * if the database was opened with #MDB_DUPSORT. The function will + * return #MDB_KEYEXIST if the key/data pair already appears in the + * database. + *
  • #MDB_NOOVERWRITE - enter the new key/data pair only if the key + * does not already appear in the database. The function will return + * #MDB_KEYEXIST if the key already appears in the database, even if + * the database supports duplicates (#MDB_DUPSORT). + *
  • #MDB_RESERVE - reserve space for data of the given size, but + * don't copy the given data. Instead, return a pointer to the + * reserved space, which the caller can fill in later. This saves + * an extra memcpy if the data is being generated later. + *
  • #MDB_APPEND - append the given key/data pair to the end of the + * database. No key comparisons are performed. This option allows + * fast bulk loading when keys are already known to be in the + * correct order. Loading unsorted keys with this flag will cause + * data corruption. + *
  • #MDB_APPENDDUP - as above, but for sorted dup data. + *
+ * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EACCES - an attempt was made to modify a read-only database. + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_cursor_put(MDB_cursor *cursor, MDB_val *key, MDB_val *data, + unsigned int flags); + + /** @brief Delete current key/data pair + * + * This function deletes the key/data pair to which the cursor refers. + * @param[in] cursor A cursor handle returned by #mdb_cursor_open() + * @param[in] flags Options for this operation. This parameter + * must be set to 0 or one of the values described here. + *
    + *
  • #MDB_NODUPDATA - delete all of the data items for the current key. + * This flag may only be specified if the database was opened with #MDB_DUPSORT. + *
+ * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EACCES - an attempt was made to modify a read-only database. + *
  • EINVAL - an invalid parameter was specified. + *
+ */ +int mdb_cursor_del(MDB_cursor *cursor, unsigned int flags); + + /** @brief Return count of duplicates for current key. + * + * This call is only valid on databases that support sorted duplicate + * data items #MDB_DUPSORT. + * @param[in] cursor A cursor handle returned by #mdb_cursor_open() + * @param[out] countp Address where the count will be stored + * @return A non-zero error value on failure and 0 on success. Some possible + * errors are: + *
    + *
  • EINVAL - cursor is not initialized, or an invalid parameter was specified. + *
+ */ +int mdb_cursor_count(MDB_cursor *cursor, size_t *countp); + + /** @brief Compare two data items according to a particular database. + * + * This returns a comparison as if the two data items were keys in the + * specified database. + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @param[in] dbi A database handle returned by #mdb_open() + * @param[in] a The first item to compare + * @param[in] b The second item to compare + * @return < 0 if a < b, 0 if a == b, > 0 if a > b + */ +int mdb_cmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b); + + /** @brief Compare two data items according to a particular database. + * + * This returns a comparison as if the two items were data items of + * a sorted duplicates #MDB_DUPSORT database. + * @param[in] txn A transaction handle returned by #mdb_txn_begin() + * @param[in] dbi A database handle returned by #mdb_open() + * @param[in] a The first item to compare + * @param[in] b The second item to compare + * @return < 0 if a < b, 0 if a == b, > 0 if a > b + */ +int mdb_dcmp(MDB_txn *txn, MDB_dbi dbi, const MDB_val *a, const MDB_val *b); +/** @} */ + +#ifdef __cplusplus +} +#endif +#endif /* _MDB_H_ */ diff --git a/c_src/midl.c b/c_src/midl.c new file mode 100644 index 0000000..9ee100d --- /dev/null +++ b/c_src/midl.c @@ -0,0 +1,327 @@ +/** @file midl.c + * @brief ldap bdb back-end ID List functions */ +/* $OpenLDAP$ */ +/* This work is part of OpenLDAP Software . + * + * Copyright 2000-2012 The OpenLDAP Foundation. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted only as authorized by the OpenLDAP + * Public License. + * + * A copy of this license is available in the file LICENSE in the + * top-level directory of the distribution or, alternatively, at + * . + */ + +#include +#include +#include +#include +#include +#include "midl.h" + +/** @defgroup internal MDB Internals + * @{ + */ +/** @defgroup idls ID List Management + * @{ + */ +#define CMP(x,y) ( (x) < (y) ? -1 : (x) > (y) ) + +#if 0 /* superseded by append/sort */ +static unsigned mdb_midl_search( MDB_IDL ids, MDB_ID id ) +{ + /* + * binary search of id in ids + * if found, returns position of id + * if not found, returns first position greater than id + */ + unsigned base = 0; + unsigned cursor = 1; + int val = 0; + unsigned n = ids[0]; + + while( 0 < n ) { + unsigned pivot = n >> 1; + cursor = base + pivot + 1; + val = CMP( ids[cursor], id ); + + if( val < 0 ) { + n = pivot; + + } else if ( val > 0 ) { + base = cursor; + n -= pivot + 1; + + } else { + return cursor; + } + } + + if( val > 0 ) { + ++cursor; + } + return cursor; +} + +int mdb_midl_insert( MDB_IDL ids, MDB_ID id ) +{ + unsigned x, i; + + if (MDB_IDL_IS_RANGE( ids )) { + /* if already in range, treat as a dup */ + if (id >= MDB_IDL_RANGE_FIRST(ids) && id <= MDB_IDL_RANGE_LAST(ids)) + return -1; + if (id < MDB_IDL_RANGE_FIRST(ids)) + ids[1] = id; + else if (id > MDB_IDL_RANGE_LAST(ids)) + ids[2] = id; + return 0; + } + + x = mdb_midl_search( ids, id ); + assert( x > 0 ); + + if( x < 1 ) { + /* internal error */ + return -2; + } + + if ( x <= ids[0] && ids[x] == id ) { + /* duplicate */ + assert(0); + return -1; + } + + if ( ++ids[0] >= MDB_IDL_DB_MAX ) { + if( id < ids[1] ) { + ids[1] = id; + ids[2] = ids[ids[0]-1]; + } else if ( ids[ids[0]-1] < id ) { + ids[2] = id; + } else { + ids[2] = ids[ids[0]-1]; + } + ids[0] = MDB_NOID; + + } else { + /* insert id */ + for (i=ids[0]; i>x; i--) + ids[i] = ids[i-1]; + ids[x] = id; + } + + return 0; +} +#endif + +MDB_IDL mdb_midl_alloc() +{ + MDB_IDL ids = malloc((MDB_IDL_UM_MAX+1) * sizeof(MDB_ID)); + *ids++ = MDB_IDL_UM_MAX; + return ids; +} + +void mdb_midl_free(MDB_IDL ids) +{ + free(ids-1); +} + +int mdb_midl_shrink( MDB_IDL *idp ) +{ + MDB_IDL ids = *idp; + if (ids[-1] > MDB_IDL_UM_MAX) { + ids = realloc(ids, (MDB_IDL_UM_MAX+1) * sizeof(MDB_ID)); + *ids++ = MDB_IDL_UM_MAX; + *idp = ids; + return 1; + } + return 0; +} + +int mdb_midl_append( MDB_IDL *idp, MDB_ID id ) +{ + MDB_IDL ids = *idp; + /* Too big? */ + if (ids[0] >= ids[-1]) { + MDB_IDL idn = ids-1; + /* grow it */ + idn = realloc(idn, (*idn + MDB_IDL_UM_MAX + 1) * sizeof(MDB_ID)); + if (!idn) + return -1; + *idn++ += MDB_IDL_UM_MAX; + ids = idn; + *idp = ids; + } + ids[0]++; + ids[ids[0]] = id; + return 0; +} + +int mdb_midl_append_list( MDB_IDL *idp, MDB_IDL app ) +{ + MDB_IDL ids = *idp; + /* Too big? */ + if (ids[0] + app[0] >= ids[-1]) { + MDB_IDL idn = ids-1; + /* grow it */ + idn = realloc(idn, (*idn + app[-1]) * sizeof(MDB_ID)); + if (!idn) + return -1; + *idn++ += app[-1]; + ids = idn; + *idp = ids; + } + memcpy(&ids[ids[0]+1], &app[1], app[0] * sizeof(MDB_ID)); + ids[0] += app[0]; + return 0; +} + +/* Quicksort + Insertion sort for small arrays */ + +#define SMALL 8 +#define SWAP(a,b) { itmp=(a); (a)=(b); (b)=itmp; } + +void +mdb_midl_sort( MDB_IDL ids ) +{ + /* Max possible depth of int-indexed tree * 2 items/level */ + int istack[sizeof(int)*CHAR_BIT * 2]; + int i,j,k,l,ir,jstack; + MDB_ID a, itmp; + + ir = ids[0]; + l = 1; + jstack = 0; + for(;;) { + if (ir - l < SMALL) { /* Insertion sort */ + for (j=l+1;j<=ir;j++) { + a = ids[j]; + for (i=j-1;i>=1;i--) { + if (ids[i] >= a) break; + ids[i+1] = ids[i]; + } + ids[i+1] = a; + } + if (jstack == 0) break; + ir = istack[jstack--]; + l = istack[jstack--]; + } else { + k = (l + ir) >> 1; /* Choose median of left, center, right */ + SWAP(ids[k], ids[l+1]); + if (ids[l] < ids[ir]) { + SWAP(ids[l], ids[ir]); + } + if (ids[l+1] < ids[ir]) { + SWAP(ids[l+1], ids[ir]); + } + if (ids[l] < ids[l+1]) { + SWAP(ids[l], ids[l+1]); + } + i = l+1; + j = ir; + a = ids[l+1]; + for(;;) { + do i++; while(ids[i] > a); + do j--; while(ids[j] < a); + if (j < i) break; + SWAP(ids[i],ids[j]); + } + ids[l+1] = ids[j]; + ids[j] = a; + jstack += 2; + if (ir-i+1 >= j-1) { + istack[jstack] = ir; + istack[jstack-1] = i; + ir = j-1; + } else { + istack[jstack] = j-1; + istack[jstack-1] = l; + l = i; + } + } + } +} + +unsigned mdb_mid2l_search( MDB_ID2L ids, MDB_ID id ) +{ + /* + * binary search of id in ids + * if found, returns position of id + * if not found, returns first position greater than id + */ + unsigned base = 0; + unsigned cursor = 1; + int val = 0; + unsigned n = ids[0].mid; + + while( 0 < n ) { + unsigned pivot = n >> 1; + cursor = base + pivot + 1; + val = CMP( id, ids[cursor].mid ); + + if( val < 0 ) { + n = pivot; + + } else if ( val > 0 ) { + base = cursor; + n -= pivot + 1; + + } else { + return cursor; + } + } + + if( val > 0 ) { + ++cursor; + } + return cursor; +} + +int mdb_mid2l_insert( MDB_ID2L ids, MDB_ID2 *id ) +{ + unsigned x, i; + + x = mdb_mid2l_search( ids, id->mid ); + assert( x > 0 ); + + if( x < 1 ) { + /* internal error */ + return -2; + } + + if ( x <= ids[0].mid && ids[x].mid == id->mid ) { + /* duplicate */ + return -1; + } + + if ( ids[0].mid >= MDB_IDL_UM_MAX ) { + /* too big */ + return -2; + + } else { + /* insert id */ + ids[0].mid++; + for (i=ids[0].mid; i>x; i--) + ids[i] = ids[i-1]; + ids[x] = *id; + } + + return 0; +} + +int mdb_mid2l_append( MDB_ID2L ids, MDB_ID2 *id ) +{ + /* Too big? */ + if (ids[0].mid >= MDB_IDL_UM_MAX) { + return -2; + } + ids[0].mid++; + ids[ids[0].mid] = *id; + return 0; +} + +/** @} */ +/** @} */ diff --git a/c_src/midl.h b/c_src/midl.h new file mode 100644 index 0000000..0fd1cfb --- /dev/null +++ b/c_src/midl.h @@ -0,0 +1,195 @@ +/** @file midl.h + * @brief mdb ID List header file. + * + * This file was originally part of back-bdb but has been + * modified for use in libmdb. Most of the macros defined + * in this file are unused, just left over from the original. + * + * This file is only used internally in libmdb and its definitions + * are not exposed publicly. + */ +/* $OpenLDAP$ */ +/* This work is part of OpenLDAP Software . + * + * Copyright 2000-2012 The OpenLDAP Foundation. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted only as authorized by the OpenLDAP + * Public License. + * + * A copy of this license is available in the file LICENSE in the + * top-level directory of the distribution or, alternatively, at + * . + */ + +#ifndef _MDB_MIDL_H_ +#define _MDB_MIDL_H_ + +#include + +#ifdef __cplusplus +extern "C" { +#endif + +/** @defgroup internal MDB Internals + * @{ + */ + +/** @defgroup idls ID List Management + * @{ + */ + /** A generic ID number. These were entryIDs in back-bdb. + * Preferably it should have the same size as a pointer. + */ +typedef size_t MDB_ID; + + /** An IDL is an ID List, a sorted array of IDs. The first + * element of the array is a counter for how many actual + * IDs are in the list. In the original back-bdb code, IDLs are + * sorted in ascending order. For libmdb IDLs are sorted in + * descending order. + */ +typedef MDB_ID *MDB_IDL; + +#define MDB_NOID (~(MDB_ID)0) + +/* IDL sizes - likely should be even bigger + * limiting factors: sizeof(ID), thread stack size + */ +#define MDB_IDL_LOGN 16 /* DB_SIZE is 2^16, UM_SIZE is 2^17 */ +#define MDB_IDL_DB_SIZE (1<bi_lastid) ) +#define MDB_IDL_ALL( bdb, ids ) MDB_IDL_RANGE( ids, 1, ((bdb)->bi_lastid) ) + +#define MDB_IDL_FIRST( ids ) ( (ids)[1] ) +#define MDB_IDL_LAST( ids ) ( MDB_IDL_IS_RANGE(ids) \ + ? (ids)[2] : (ids)[(ids)[0]] ) + +#define MDB_IDL_N( ids ) ( MDB_IDL_IS_RANGE(ids) \ + ? ((ids)[2]-(ids)[1])+1 : (ids)[0] ) + +#if 0 /* superseded by append/sort */ + /** Insert an ID into an IDL. + * @param[in,out] ids The IDL to insert into. + * @param[in] id The ID to insert. + * @return 0 on success, -1 if the ID was already present in the IDL. + */ +int mdb_midl_insert( MDB_IDL ids, MDB_ID id ); +#endif + + /** Allocate an IDL. + * Allocates memory for an IDL of a default size. + * @return IDL on success, NULL on failure. + */ +MDB_IDL mdb_midl_alloc(); + + /** Free an IDL. + * @param[in] ids The IDL to free. + */ +void mdb_midl_free(MDB_IDL ids); + + /** Shrink an IDL. + * Return the IDL to the default size if it has grown larger. + * @param[in,out] idp Address of the IDL to shrink. + * @return 0 on no change, non-zero if shrunk. + */ +int mdb_midl_shrink(MDB_IDL *idp); + + /** Append an ID onto an IDL. + * @param[in,out] idp Address of the IDL to append to. + * @param[in] id The ID to append. + * @return 0 on success, -1 if the IDL is too large. + */ +int mdb_midl_append( MDB_IDL *idp, MDB_ID id ); + + /** Append an IDL onto an IDL. + * @param[in,out] idp Address of the IDL to append to. + * @param[in] app The IDL to append. + * @return 0 on success, -1 if the IDL is too large. + */ +int mdb_midl_append_list( MDB_IDL *idp, MDB_IDL app ); + + /** Sort an IDL. + * @param[in,out] ids The IDL to sort. + */ +void mdb_midl_sort( MDB_IDL ids ); + + /** An ID2 is an ID/pointer pair. + */ +typedef struct MDB_ID2 { + MDB_ID mid; /**< The ID */ + void *mptr; /**< The pointer */ +} MDB_ID2; + + /** An ID2L is an ID2 List, a sorted array of ID2s. + * The first element's \b mid member is a count of how many actual + * elements are in the array. The \b mptr member of the first element is unused. + * The array is sorted in ascending order by \b mid. + */ +typedef MDB_ID2 *MDB_ID2L; + + /** Search for an ID in an ID2L. + * @param[in] ids The ID2L to search. + * @param[in] id The ID to search for. + * @return The index of the first ID2 whose \b mid member is greater than or equal to \b id. + */ +unsigned mdb_mid2l_search( MDB_ID2L ids, MDB_ID id ); + + + /** Insert an ID2 into a ID2L. + * @param[in,out] ids The ID2L to insert into. + * @param[in] id The ID2 to insert. + * @return 0 on success, -1 if the ID was already present in the ID2L. + */ +int mdb_mid2l_insert( MDB_ID2L ids, MDB_ID2 *id ); + + /** Append an ID2 into a ID2L. + * @param[in,out] ids The ID2L to append into. + * @param[in] id The ID2 to append. + * @return 0 on success, -2 if the ID2L is too big. + */ +int mdb_mid2l_append( MDB_ID2L ids, MDB_ID2 *id ); + +/** @} */ +/** @} */ +#ifdef __cplusplus +} +#endif +#endif /* _MDB_MIDL_H_ */ diff --git a/c_src/uthash.h b/c_src/uthash.h new file mode 100644 index 0000000..9f83fc3 --- /dev/null +++ b/c_src/uthash.h @@ -0,0 +1,915 @@ +/* +Copyright (c) 2003-2012, Troy D. Hanson http://uthash.sourceforge.net +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS +IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED +TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A +PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER +OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, +EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, +PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR +PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF +LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING +NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +*/ + +#ifndef UTHASH_H +#define UTHASH_H + +#include /* memcmp,strlen */ +#include /* ptrdiff_t */ +#include /* exit() */ + +/* These macros use decltype or the earlier __typeof GNU extension. + As decltype is only available in newer compilers (VS2010 or gcc 4.3+ + when compiling c++ source) this code uses whatever method is needed + or, for VS2008 where neither is available, uses casting workarounds. */ +#ifdef _MSC_VER /* MS compiler */ +#if _MSC_VER >= 1600 && defined(__cplusplus) /* VS2010 or newer in C++ mode */ +#define DECLTYPE(x) (decltype(x)) +#else /* VS2008 or older (or VS2010 in C mode) */ +#define NO_DECLTYPE +#define DECLTYPE(x) +#endif +#else /* GNU, Sun and other compilers */ +#define DECLTYPE(x) (__typeof(x)) +#endif + +#ifdef NO_DECLTYPE +#define DECLTYPE_ASSIGN(dst,src) \ +do { \ + char **_da_dst = (char**)(&(dst)); \ + *_da_dst = (char*)(src); \ +} while(0) +#else +#define DECLTYPE_ASSIGN(dst,src) \ +do { \ + (dst) = DECLTYPE(dst)(src); \ +} while(0) +#endif + +/* a number of the hash function use uint32_t which isn't defined on win32 */ +#ifdef _MSC_VER +typedef unsigned int uint32_t; +typedef unsigned char uint8_t; +#else +#include /* uint32_t */ +#endif + +#define UTHASH_VERSION 1.9.6 + +#ifndef uthash_fatal +#define uthash_fatal(msg) exit(-1) /* fatal error (out of memory,etc) */ +#endif +#ifndef uthash_malloc +#define uthash_malloc(sz) malloc(sz) /* malloc fcn */ +#endif +#ifndef uthash_free +#define uthash_free(ptr,sz) free(ptr) /* free fcn */ +#endif + +#ifndef uthash_noexpand_fyi +#define uthash_noexpand_fyi(tbl) /* can be defined to log noexpand */ +#endif +#ifndef uthash_expand_fyi +#define uthash_expand_fyi(tbl) /* can be defined to log expands */ +#endif + +/* initial number of buckets */ +#define HASH_INITIAL_NUM_BUCKETS 32 /* initial number of buckets */ +#define HASH_INITIAL_NUM_BUCKETS_LOG2 5 /* lg2 of initial number of buckets */ +#define HASH_BKT_CAPACITY_THRESH 10 /* expand when bucket count reaches */ + +/* calculate the element whose hash handle address is hhe */ +#define ELMT_FROM_HH(tbl,hhp) ((void*)(((char*)(hhp)) - ((tbl)->hho))) + +#define HASH_FIND(hh,head,keyptr,keylen,out) \ +do { \ + unsigned _hf_bkt,_hf_hashv; \ + out=NULL; \ + if (head) { \ + HASH_FCN(keyptr,keylen, (head)->hh.tbl->num_buckets, _hf_hashv, _hf_bkt); \ + if (HASH_BLOOM_TEST((head)->hh.tbl, _hf_hashv)) { \ + HASH_FIND_IN_BKT((head)->hh.tbl, hh, (head)->hh.tbl->buckets[ _hf_bkt ], \ + keyptr,keylen,out); \ + } \ + } \ +} while (0) + +#ifdef HASH_BLOOM +#define HASH_BLOOM_BITLEN (1ULL << HASH_BLOOM) +#define HASH_BLOOM_BYTELEN (HASH_BLOOM_BITLEN/8) + ((HASH_BLOOM_BITLEN%8) ? 1:0) +#define HASH_BLOOM_MAKE(tbl) \ +do { \ + (tbl)->bloom_nbits = HASH_BLOOM; \ + (tbl)->bloom_bv = (uint8_t*)uthash_malloc(HASH_BLOOM_BYTELEN); \ + if (!((tbl)->bloom_bv)) { uthash_fatal( "out of memory"); } \ + memset((tbl)->bloom_bv, 0, HASH_BLOOM_BYTELEN); \ + (tbl)->bloom_sig = HASH_BLOOM_SIGNATURE; \ +} while (0) + +#define HASH_BLOOM_FREE(tbl) \ +do { \ + uthash_free((tbl)->bloom_bv, HASH_BLOOM_BYTELEN); \ +} while (0) + +#define HASH_BLOOM_BITSET(bv,idx) (bv[(idx)/8] |= (1U << ((idx)%8))) +#define HASH_BLOOM_BITTEST(bv,idx) (bv[(idx)/8] & (1U << ((idx)%8))) + +#define HASH_BLOOM_ADD(tbl,hashv) \ + HASH_BLOOM_BITSET((tbl)->bloom_bv, (hashv & (uint32_t)((1ULL << (tbl)->bloom_nbits) - 1))) + +#define HASH_BLOOM_TEST(tbl,hashv) \ + HASH_BLOOM_BITTEST((tbl)->bloom_bv, (hashv & (uint32_t)((1ULL << (tbl)->bloom_nbits) - 1))) + +#else +#define HASH_BLOOM_MAKE(tbl) +#define HASH_BLOOM_FREE(tbl) +#define HASH_BLOOM_ADD(tbl,hashv) +#define HASH_BLOOM_TEST(tbl,hashv) (1) +#endif + +#define HASH_MAKE_TABLE(hh,head) \ +do { \ + (head)->hh.tbl = (UT_hash_table*)uthash_malloc( \ + sizeof(UT_hash_table)); \ + if (!((head)->hh.tbl)) { uthash_fatal( "out of memory"); } \ + memset((head)->hh.tbl, 0, sizeof(UT_hash_table)); \ + (head)->hh.tbl->tail = &((head)->hh); \ + (head)->hh.tbl->num_buckets = HASH_INITIAL_NUM_BUCKETS; \ + (head)->hh.tbl->log2_num_buckets = HASH_INITIAL_NUM_BUCKETS_LOG2; \ + (head)->hh.tbl->hho = (char*)(&(head)->hh) - (char*)(head); \ + (head)->hh.tbl->buckets = (UT_hash_bucket*)uthash_malloc( \ + HASH_INITIAL_NUM_BUCKETS*sizeof(struct UT_hash_bucket)); \ + if (! (head)->hh.tbl->buckets) { uthash_fatal( "out of memory"); } \ + memset((head)->hh.tbl->buckets, 0, \ + HASH_INITIAL_NUM_BUCKETS*sizeof(struct UT_hash_bucket)); \ + HASH_BLOOM_MAKE((head)->hh.tbl); \ + (head)->hh.tbl->signature = HASH_SIGNATURE; \ +} while(0) + +#define HASH_ADD(hh,head,fieldname,keylen_in,add) \ + HASH_ADD_KEYPTR(hh,head,&((add)->fieldname),keylen_in,add) + +#define HASH_ADD_KEYPTR(hh,head,keyptr,keylen_in,add) \ +do { \ + unsigned _ha_bkt; \ + (add)->hh.next = NULL; \ + (add)->hh.key = (char*)keyptr; \ + (add)->hh.keylen = (unsigned)keylen_in; \ + if (!(head)) { \ + head = (add); \ + (head)->hh.prev = NULL; \ + HASH_MAKE_TABLE(hh,head); \ + } else { \ + (head)->hh.tbl->tail->next = (add); \ + (add)->hh.prev = ELMT_FROM_HH((head)->hh.tbl, (head)->hh.tbl->tail); \ + (head)->hh.tbl->tail = &((add)->hh); \ + } \ + (head)->hh.tbl->num_items++; \ + (add)->hh.tbl = (head)->hh.tbl; \ + HASH_FCN(keyptr,keylen_in, (head)->hh.tbl->num_buckets, \ + (add)->hh.hashv, _ha_bkt); \ + HASH_ADD_TO_BKT((head)->hh.tbl->buckets[_ha_bkt],&(add)->hh); \ + HASH_BLOOM_ADD((head)->hh.tbl,(add)->hh.hashv); \ + HASH_EMIT_KEY(hh,head,keyptr,keylen_in); \ + HASH_FSCK(hh,head); \ +} while(0) + +#define HASH_TO_BKT( hashv, num_bkts, bkt ) \ +do { \ + bkt = ((hashv) & ((num_bkts) - 1)); \ +} while(0) + +/* delete "delptr" from the hash table. + * "the usual" patch-up process for the app-order doubly-linked-list. + * The use of _hd_hh_del below deserves special explanation. + * These used to be expressed using (delptr) but that led to a bug + * if someone used the same symbol for the head and deletee, like + * HASH_DELETE(hh,users,users); + * We want that to work, but by changing the head (users) below + * we were forfeiting our ability to further refer to the deletee (users) + * in the patch-up process. Solution: use scratch space to + * copy the deletee pointer, then the latter references are via that + * scratch pointer rather than through the repointed (users) symbol. + */ +#define HASH_DELETE(hh,head,delptr) \ +do { \ + unsigned _hd_bkt; \ + struct UT_hash_handle *_hd_hh_del; \ + if ( ((delptr)->hh.prev == NULL) && ((delptr)->hh.next == NULL) ) { \ + uthash_free((head)->hh.tbl->buckets, \ + (head)->hh.tbl->num_buckets*sizeof(struct UT_hash_bucket) ); \ + HASH_BLOOM_FREE((head)->hh.tbl); \ + uthash_free((head)->hh.tbl, sizeof(UT_hash_table)); \ + head = NULL; \ + } else { \ + _hd_hh_del = &((delptr)->hh); \ + if ((delptr) == ELMT_FROM_HH((head)->hh.tbl,(head)->hh.tbl->tail)) { \ + (head)->hh.tbl->tail = \ + (UT_hash_handle*)((char*)((delptr)->hh.prev) + \ + (head)->hh.tbl->hho); \ + } \ + if ((delptr)->hh.prev) { \ + ((UT_hash_handle*)((char*)((delptr)->hh.prev) + \ + (head)->hh.tbl->hho))->next = (delptr)->hh.next; \ + } else { \ + DECLTYPE_ASSIGN(head,(delptr)->hh.next); \ + } \ + if (_hd_hh_del->next) { \ + ((UT_hash_handle*)((char*)_hd_hh_del->next + \ + (head)->hh.tbl->hho))->prev = \ + _hd_hh_del->prev; \ + } \ + HASH_TO_BKT( _hd_hh_del->hashv, (head)->hh.tbl->num_buckets, _hd_bkt); \ + HASH_DEL_IN_BKT(hh,(head)->hh.tbl->buckets[_hd_bkt], _hd_hh_del); \ + (head)->hh.tbl->num_items--; \ + } \ + HASH_FSCK(hh,head); \ +} while (0) + + +/* convenience forms of HASH_FIND/HASH_ADD/HASH_DEL */ +#define HASH_FIND_STR(head,findstr,out) \ + HASH_FIND(hh,head,findstr,strlen(findstr),out) +#define HASH_ADD_STR(head,strfield,add) \ + HASH_ADD(hh,head,strfield,strlen(add->strfield),add) +#define HASH_FIND_INT(head,findint,out) \ + HASH_FIND(hh,head,findint,sizeof(int),out) +#define HASH_ADD_INT(head,intfield,add) \ + HASH_ADD(hh,head,intfield,sizeof(int),add) +#define HASH_FIND_PTR(head,findptr,out) \ + HASH_FIND(hh,head,findptr,sizeof(void *),out) +#define HASH_ADD_PTR(head,ptrfield,add) \ + HASH_ADD(hh,head,ptrfield,sizeof(void *),add) +#define HASH_DEL(head,delptr) \ + HASH_DELETE(hh,head,delptr) + +/* HASH_FSCK checks hash integrity on every add/delete when HASH_DEBUG is defined. + * This is for uthash developer only; it compiles away if HASH_DEBUG isn't defined. + */ +#ifdef HASH_DEBUG +#define HASH_OOPS(...) do { fprintf(stderr,__VA_ARGS__); exit(-1); } while (0) +#define HASH_FSCK(hh,head) \ +do { \ + unsigned _bkt_i; \ + unsigned _count, _bkt_count; \ + char *_prev; \ + struct UT_hash_handle *_thh; \ + if (head) { \ + _count = 0; \ + for( _bkt_i = 0; _bkt_i < (head)->hh.tbl->num_buckets; _bkt_i++) { \ + _bkt_count = 0; \ + _thh = (head)->hh.tbl->buckets[_bkt_i].hh_head; \ + _prev = NULL; \ + while (_thh) { \ + if (_prev != (char*)(_thh->hh_prev)) { \ + HASH_OOPS("invalid hh_prev %p, actual %p\n", \ + _thh->hh_prev, _prev ); \ + } \ + _bkt_count++; \ + _prev = (char*)(_thh); \ + _thh = _thh->hh_next; \ + } \ + _count += _bkt_count; \ + if ((head)->hh.tbl->buckets[_bkt_i].count != _bkt_count) { \ + HASH_OOPS("invalid bucket count %d, actual %d\n", \ + (head)->hh.tbl->buckets[_bkt_i].count, _bkt_count); \ + } \ + } \ + if (_count != (head)->hh.tbl->num_items) { \ + HASH_OOPS("invalid hh item count %d, actual %d\n", \ + (head)->hh.tbl->num_items, _count ); \ + } \ + /* traverse hh in app order; check next/prev integrity, count */ \ + _count = 0; \ + _prev = NULL; \ + _thh = &(head)->hh; \ + while (_thh) { \ + _count++; \ + if (_prev !=(char*)(_thh->prev)) { \ + HASH_OOPS("invalid prev %p, actual %p\n", \ + _thh->prev, _prev ); \ + } \ + _prev = (char*)ELMT_FROM_HH((head)->hh.tbl, _thh); \ + _thh = ( _thh->next ? (UT_hash_handle*)((char*)(_thh->next) + \ + (head)->hh.tbl->hho) : NULL ); \ + } \ + if (_count != (head)->hh.tbl->num_items) { \ + HASH_OOPS("invalid app item count %d, actual %d\n", \ + (head)->hh.tbl->num_items, _count ); \ + } \ + } \ +} while (0) +#else +#define HASH_FSCK(hh,head) +#endif + +/* When compiled with -DHASH_EMIT_KEYS, length-prefixed keys are emitted to + * the descriptor to which this macro is defined for tuning the hash function. + * The app can #include to get the prototype for write(2). */ +#ifdef HASH_EMIT_KEYS +#define HASH_EMIT_KEY(hh,head,keyptr,fieldlen) \ +do { \ + unsigned _klen = fieldlen; \ + write(HASH_EMIT_KEYS, &_klen, sizeof(_klen)); \ + write(HASH_EMIT_KEYS, keyptr, fieldlen); \ +} while (0) +#else +#define HASH_EMIT_KEY(hh,head,keyptr,fieldlen) +#endif + +/* default to Jenkin's hash unless overridden e.g. DHASH_FUNCTION=HASH_SAX */ +#ifdef HASH_FUNCTION +#define HASH_FCN HASH_FUNCTION +#else +#define HASH_FCN HASH_JEN +#endif + +/* The Bernstein hash function, used in Perl prior to v5.6 */ +#define HASH_BER(key,keylen,num_bkts,hashv,bkt) \ +do { \ + unsigned _hb_keylen=keylen; \ + char *_hb_key=(char*)(key); \ + (hashv) = 0; \ + while (_hb_keylen--) { (hashv) = ((hashv) * 33) + *_hb_key++; } \ + bkt = (hashv) & (num_bkts-1); \ +} while (0) + + +/* SAX/FNV/OAT/JEN hash functions are macro variants of those listed at + * http://eternallyconfuzzled.com/tuts/algorithms/jsw_tut_hashing.aspx */ +#define HASH_SAX(key,keylen,num_bkts,hashv,bkt) \ +do { \ + unsigned _sx_i; \ + char *_hs_key=(char*)(key); \ + hashv = 0; \ + for(_sx_i=0; _sx_i < keylen; _sx_i++) \ + hashv ^= (hashv << 5) + (hashv >> 2) + _hs_key[_sx_i]; \ + bkt = hashv & (num_bkts-1); \ +} while (0) + +#define HASH_FNV(key,keylen,num_bkts,hashv,bkt) \ +do { \ + unsigned _fn_i; \ + char *_hf_key=(char*)(key); \ + hashv = 2166136261UL; \ + for(_fn_i=0; _fn_i < keylen; _fn_i++) \ + hashv = (hashv * 16777619) ^ _hf_key[_fn_i]; \ + bkt = hashv & (num_bkts-1); \ +} while(0) + +#define HASH_OAT(key,keylen,num_bkts,hashv,bkt) \ +do { \ + unsigned _ho_i; \ + char *_ho_key=(char*)(key); \ + hashv = 0; \ + for(_ho_i=0; _ho_i < keylen; _ho_i++) { \ + hashv += _ho_key[_ho_i]; \ + hashv += (hashv << 10); \ + hashv ^= (hashv >> 6); \ + } \ + hashv += (hashv << 3); \ + hashv ^= (hashv >> 11); \ + hashv += (hashv << 15); \ + bkt = hashv & (num_bkts-1); \ +} while(0) + +#define HASH_JEN_MIX(a,b,c) \ +do { \ + a -= b; a -= c; a ^= ( c >> 13 ); \ + b -= c; b -= a; b ^= ( a << 8 ); \ + c -= a; c -= b; c ^= ( b >> 13 ); \ + a -= b; a -= c; a ^= ( c >> 12 ); \ + b -= c; b -= a; b ^= ( a << 16 ); \ + c -= a; c -= b; c ^= ( b >> 5 ); \ + a -= b; a -= c; a ^= ( c >> 3 ); \ + b -= c; b -= a; b ^= ( a << 10 ); \ + c -= a; c -= b; c ^= ( b >> 15 ); \ +} while (0) + +#define HASH_JEN(key,keylen,num_bkts,hashv,bkt) \ +do { \ + unsigned _hj_i,_hj_j,_hj_k; \ + char *_hj_key=(char*)(key); \ + hashv = 0xfeedbeef; \ + _hj_i = _hj_j = 0x9e3779b9; \ + _hj_k = (unsigned)keylen; \ + while (_hj_k >= 12) { \ + _hj_i += (_hj_key[0] + ( (unsigned)_hj_key[1] << 8 ) \ + + ( (unsigned)_hj_key[2] << 16 ) \ + + ( (unsigned)_hj_key[3] << 24 ) ); \ + _hj_j += (_hj_key[4] + ( (unsigned)_hj_key[5] << 8 ) \ + + ( (unsigned)_hj_key[6] << 16 ) \ + + ( (unsigned)_hj_key[7] << 24 ) ); \ + hashv += (_hj_key[8] + ( (unsigned)_hj_key[9] << 8 ) \ + + ( (unsigned)_hj_key[10] << 16 ) \ + + ( (unsigned)_hj_key[11] << 24 ) ); \ + \ + HASH_JEN_MIX(_hj_i, _hj_j, hashv); \ + \ + _hj_key += 12; \ + _hj_k -= 12; \ + } \ + hashv += keylen; \ + switch ( _hj_k ) { \ + case 11: hashv += ( (unsigned)_hj_key[10] << 24 ); \ + case 10: hashv += ( (unsigned)_hj_key[9] << 16 ); \ + case 9: hashv += ( (unsigned)_hj_key[8] << 8 ); \ + case 8: _hj_j += ( (unsigned)_hj_key[7] << 24 ); \ + case 7: _hj_j += ( (unsigned)_hj_key[6] << 16 ); \ + case 6: _hj_j += ( (unsigned)_hj_key[5] << 8 ); \ + case 5: _hj_j += _hj_key[4]; \ + case 4: _hj_i += ( (unsigned)_hj_key[3] << 24 ); \ + case 3: _hj_i += ( (unsigned)_hj_key[2] << 16 ); \ + case 2: _hj_i += ( (unsigned)_hj_key[1] << 8 ); \ + case 1: _hj_i += _hj_key[0]; \ + } \ + HASH_JEN_MIX(_hj_i, _hj_j, hashv); \ + bkt = hashv & (num_bkts-1); \ +} while(0) + +/* The Paul Hsieh hash function */ +#undef get16bits +#if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__) \ + || defined(_MSC_VER) || defined (__BORLANDC__) || defined (__TURBOC__) +#define get16bits(d) (*((const uint16_t *) (d))) +#endif + +#if !defined (get16bits) +#define get16bits(d) ((((uint32_t)(((const uint8_t *)(d))[1])) << 8) \ + +(uint32_t)(((const uint8_t *)(d))[0]) ) +#endif +#define HASH_SFH(key,keylen,num_bkts,hashv,bkt) \ +do { \ + char *_sfh_key=(char*)(key); \ + uint32_t _sfh_tmp, _sfh_len = keylen; \ + \ + int _sfh_rem = _sfh_len & 3; \ + _sfh_len >>= 2; \ + hashv = 0xcafebabe; \ + \ + /* Main loop */ \ + for (;_sfh_len > 0; _sfh_len--) { \ + hashv += get16bits (_sfh_key); \ + _sfh_tmp = (get16bits (_sfh_key+2) << 11) ^ hashv; \ + hashv = (hashv << 16) ^ _sfh_tmp; \ + _sfh_key += 2*sizeof (uint16_t); \ + hashv += hashv >> 11; \ + } \ + \ + /* Handle end cases */ \ + switch (_sfh_rem) { \ + case 3: hashv += get16bits (_sfh_key); \ + hashv ^= hashv << 16; \ + hashv ^= _sfh_key[sizeof (uint16_t)] << 18; \ + hashv += hashv >> 11; \ + break; \ + case 2: hashv += get16bits (_sfh_key); \ + hashv ^= hashv << 11; \ + hashv += hashv >> 17; \ + break; \ + case 1: hashv += *_sfh_key; \ + hashv ^= hashv << 10; \ + hashv += hashv >> 1; \ + } \ + \ + /* Force "avalanching" of final 127 bits */ \ + hashv ^= hashv << 3; \ + hashv += hashv >> 5; \ + hashv ^= hashv << 4; \ + hashv += hashv >> 17; \ + hashv ^= hashv << 25; \ + hashv += hashv >> 6; \ + bkt = hashv & (num_bkts-1); \ +} while(0) + +#ifdef HASH_USING_NO_STRICT_ALIASING +/* The MurmurHash exploits some CPU's (x86,x86_64) tolerance for unaligned reads. + * For other types of CPU's (e.g. Sparc) an unaligned read causes a bus error. + * MurmurHash uses the faster approach only on CPU's where we know it's safe. + * + * Note the preprocessor built-in defines can be emitted using: + * + * gcc -m64 -dM -E - < /dev/null (on gcc) + * cc -## a.c (where a.c is a simple test file) (Sun Studio) + */ +#if (defined(__i386__) || defined(__x86_64__)) +#define MUR_GETBLOCK(p,i) p[i] +#else /* non intel */ +#define MUR_PLUS0_ALIGNED(p) (((unsigned long)p & 0x3) == 0) +#define MUR_PLUS1_ALIGNED(p) (((unsigned long)p & 0x3) == 1) +#define MUR_PLUS2_ALIGNED(p) (((unsigned long)p & 0x3) == 2) +#define MUR_PLUS3_ALIGNED(p) (((unsigned long)p & 0x3) == 3) +#define WP(p) ((uint32_t*)((unsigned long)(p) & ~3UL)) +#if (defined(__BIG_ENDIAN__) || defined(SPARC) || defined(__ppc__) || defined(__ppc64__)) +#define MUR_THREE_ONE(p) ((((*WP(p))&0x00ffffff) << 8) | (((*(WP(p)+1))&0xff000000) >> 24)) +#define MUR_TWO_TWO(p) ((((*WP(p))&0x0000ffff) <<16) | (((*(WP(p)+1))&0xffff0000) >> 16)) +#define MUR_ONE_THREE(p) ((((*WP(p))&0x000000ff) <<24) | (((*(WP(p)+1))&0xffffff00) >> 8)) +#else /* assume little endian non-intel */ +#define MUR_THREE_ONE(p) ((((*WP(p))&0xffffff00) >> 8) | (((*(WP(p)+1))&0x000000ff) << 24)) +#define MUR_TWO_TWO(p) ((((*WP(p))&0xffff0000) >>16) | (((*(WP(p)+1))&0x0000ffff) << 16)) +#define MUR_ONE_THREE(p) ((((*WP(p))&0xff000000) >>24) | (((*(WP(p)+1))&0x00ffffff) << 8)) +#endif +#define MUR_GETBLOCK(p,i) (MUR_PLUS0_ALIGNED(p) ? ((p)[i]) : \ + (MUR_PLUS1_ALIGNED(p) ? MUR_THREE_ONE(p) : \ + (MUR_PLUS2_ALIGNED(p) ? MUR_TWO_TWO(p) : \ + MUR_ONE_THREE(p)))) +#endif +#define MUR_ROTL32(x,r) (((x) << (r)) | ((x) >> (32 - (r)))) +#define MUR_FMIX(_h) \ +do { \ + _h ^= _h >> 16; \ + _h *= 0x85ebca6b; \ + _h ^= _h >> 13; \ + _h *= 0xc2b2ae35l; \ + _h ^= _h >> 16; \ +} while(0) + +#define HASH_MUR(key,keylen,num_bkts,hashv,bkt) \ +do { \ + const uint8_t *_mur_data = (const uint8_t*)(key); \ + const int _mur_nblocks = (keylen) / 4; \ + uint32_t _mur_h1 = 0xf88D5353; \ + uint32_t _mur_c1 = 0xcc9e2d51; \ + uint32_t _mur_c2 = 0x1b873593; \ + const uint32_t *_mur_blocks = (const uint32_t*)(_mur_data+_mur_nblocks*4); \ + int _mur_i; \ + for(_mur_i = -_mur_nblocks; _mur_i; _mur_i++) { \ + uint32_t _mur_k1 = MUR_GETBLOCK(_mur_blocks,_mur_i); \ + _mur_k1 *= _mur_c1; \ + _mur_k1 = MUR_ROTL32(_mur_k1,15); \ + _mur_k1 *= _mur_c2; \ + \ + _mur_h1 ^= _mur_k1; \ + _mur_h1 = MUR_ROTL32(_mur_h1,13); \ + _mur_h1 = _mur_h1*5+0xe6546b64; \ + } \ + const uint8_t *_mur_tail = (const uint8_t*)(_mur_data + _mur_nblocks*4); \ + uint32_t _mur_k1=0; \ + switch((keylen) & 3) { \ + case 3: _mur_k1 ^= _mur_tail[2] << 16; \ + case 2: _mur_k1 ^= _mur_tail[1] << 8; \ + case 1: _mur_k1 ^= _mur_tail[0]; \ + _mur_k1 *= _mur_c1; \ + _mur_k1 = MUR_ROTL32(_mur_k1,15); \ + _mur_k1 *= _mur_c2; \ + _mur_h1 ^= _mur_k1; \ + } \ + _mur_h1 ^= (keylen); \ + MUR_FMIX(_mur_h1); \ + hashv = _mur_h1; \ + bkt = hashv & (num_bkts-1); \ +} while(0) +#endif /* HASH_USING_NO_STRICT_ALIASING */ + +/* key comparison function; return 0 if keys equal */ +#define HASH_KEYCMP(a,b,len) memcmp(a,b,len) + +/* iterate over items in a known bucket to find desired item */ +#define HASH_FIND_IN_BKT(tbl,hh,head,keyptr,keylen_in,out) \ +do { \ + if (head.hh_head) DECLTYPE_ASSIGN(out,ELMT_FROM_HH(tbl,head.hh_head)); \ + else out=NULL; \ + while (out) { \ + if ((out)->hh.keylen == keylen_in) { \ + if ((HASH_KEYCMP((out)->hh.key,keyptr,keylen_in)) == 0) break; \ + } \ + if ((out)->hh.hh_next) DECLTYPE_ASSIGN(out,ELMT_FROM_HH(tbl,(out)->hh.hh_next)); \ + else out = NULL; \ + } \ +} while(0) + +/* add an item to a bucket */ +#define HASH_ADD_TO_BKT(head,addhh) \ +do { \ + head.count++; \ + (addhh)->hh_next = head.hh_head; \ + (addhh)->hh_prev = NULL; \ + if (head.hh_head) { (head).hh_head->hh_prev = (addhh); } \ + (head).hh_head=addhh; \ + if (head.count >= ((head.expand_mult+1) * HASH_BKT_CAPACITY_THRESH) \ + && (addhh)->tbl->noexpand != 1) { \ + HASH_EXPAND_BUCKETS((addhh)->tbl); \ + } \ +} while(0) + +/* remove an item from a given bucket */ +#define HASH_DEL_IN_BKT(hh,head,hh_del) \ + (head).count--; \ + if ((head).hh_head == hh_del) { \ + (head).hh_head = hh_del->hh_next; \ + } \ + if (hh_del->hh_prev) { \ + hh_del->hh_prev->hh_next = hh_del->hh_next; \ + } \ + if (hh_del->hh_next) { \ + hh_del->hh_next->hh_prev = hh_del->hh_prev; \ + } + +/* Bucket expansion has the effect of doubling the number of buckets + * and redistributing the items into the new buckets. Ideally the + * items will distribute more or less evenly into the new buckets + * (the extent to which this is true is a measure of the quality of + * the hash function as it applies to the key domain). + * + * With the items distributed into more buckets, the chain length + * (item count) in each bucket is reduced. Thus by expanding buckets + * the hash keeps a bound on the chain length. This bounded chain + * length is the essence of how a hash provides constant time lookup. + * + * The calculation of tbl->ideal_chain_maxlen below deserves some + * explanation. First, keep in mind that we're calculating the ideal + * maximum chain length based on the *new* (doubled) bucket count. + * In fractions this is just n/b (n=number of items,b=new num buckets). + * Since the ideal chain length is an integer, we want to calculate + * ceil(n/b). We don't depend on floating point arithmetic in this + * hash, so to calculate ceil(n/b) with integers we could write + * + * ceil(n/b) = (n/b) + ((n%b)?1:0) + * + * and in fact a previous version of this hash did just that. + * But now we have improved things a bit by recognizing that b is + * always a power of two. We keep its base 2 log handy (call it lb), + * so now we can write this with a bit shift and logical AND: + * + * ceil(n/b) = (n>>lb) + ( (n & (b-1)) ? 1:0) + * + */ +#define HASH_EXPAND_BUCKETS(tbl) \ +do { \ + unsigned _he_bkt; \ + unsigned _he_bkt_i; \ + struct UT_hash_handle *_he_thh, *_he_hh_nxt; \ + UT_hash_bucket *_he_new_buckets, *_he_newbkt; \ + _he_new_buckets = (UT_hash_bucket*)uthash_malloc( \ + 2 * tbl->num_buckets * sizeof(struct UT_hash_bucket)); \ + if (!_he_new_buckets) { uthash_fatal( "out of memory"); } \ + memset(_he_new_buckets, 0, \ + 2 * tbl->num_buckets * sizeof(struct UT_hash_bucket)); \ + tbl->ideal_chain_maxlen = \ + (tbl->num_items >> (tbl->log2_num_buckets+1)) + \ + ((tbl->num_items & ((tbl->num_buckets*2)-1)) ? 1 : 0); \ + tbl->nonideal_items = 0; \ + for(_he_bkt_i = 0; _he_bkt_i < tbl->num_buckets; _he_bkt_i++) \ + { \ + _he_thh = tbl->buckets[ _he_bkt_i ].hh_head; \ + while (_he_thh) { \ + _he_hh_nxt = _he_thh->hh_next; \ + HASH_TO_BKT( _he_thh->hashv, tbl->num_buckets*2, _he_bkt); \ + _he_newbkt = &(_he_new_buckets[ _he_bkt ]); \ + if (++(_he_newbkt->count) > tbl->ideal_chain_maxlen) { \ + tbl->nonideal_items++; \ + _he_newbkt->expand_mult = _he_newbkt->count / \ + tbl->ideal_chain_maxlen; \ + } \ + _he_thh->hh_prev = NULL; \ + _he_thh->hh_next = _he_newbkt->hh_head; \ + if (_he_newbkt->hh_head) _he_newbkt->hh_head->hh_prev = \ + _he_thh; \ + _he_newbkt->hh_head = _he_thh; \ + _he_thh = _he_hh_nxt; \ + } \ + } \ + uthash_free( tbl->buckets, tbl->num_buckets*sizeof(struct UT_hash_bucket) ); \ + tbl->num_buckets *= 2; \ + tbl->log2_num_buckets++; \ + tbl->buckets = _he_new_buckets; \ + tbl->ineff_expands = (tbl->nonideal_items > (tbl->num_items >> 1)) ? \ + (tbl->ineff_expands+1) : 0; \ + if (tbl->ineff_expands > 1) { \ + tbl->noexpand=1; \ + uthash_noexpand_fyi(tbl); \ + } \ + uthash_expand_fyi(tbl); \ +} while(0) + + +/* This is an adaptation of Simon Tatham's O(n log(n)) mergesort */ +/* Note that HASH_SORT assumes the hash handle name to be hh. + * HASH_SRT was added to allow the hash handle name to be passed in. */ +#define HASH_SORT(head,cmpfcn) HASH_SRT(hh,head,cmpfcn) +#define HASH_SRT(hh,head,cmpfcn) \ +do { \ + unsigned _hs_i; \ + unsigned _hs_looping,_hs_nmerges,_hs_insize,_hs_psize,_hs_qsize; \ + struct UT_hash_handle *_hs_p, *_hs_q, *_hs_e, *_hs_list, *_hs_tail; \ + if (head) { \ + _hs_insize = 1; \ + _hs_looping = 1; \ + _hs_list = &((head)->hh); \ + while (_hs_looping) { \ + _hs_p = _hs_list; \ + _hs_list = NULL; \ + _hs_tail = NULL; \ + _hs_nmerges = 0; \ + while (_hs_p) { \ + _hs_nmerges++; \ + _hs_q = _hs_p; \ + _hs_psize = 0; \ + for ( _hs_i = 0; _hs_i < _hs_insize; _hs_i++ ) { \ + _hs_psize++; \ + _hs_q = (UT_hash_handle*)((_hs_q->next) ? \ + ((void*)((char*)(_hs_q->next) + \ + (head)->hh.tbl->hho)) : NULL); \ + if (! (_hs_q) ) break; \ + } \ + _hs_qsize = _hs_insize; \ + while ((_hs_psize > 0) || ((_hs_qsize > 0) && _hs_q )) { \ + if (_hs_psize == 0) { \ + _hs_e = _hs_q; \ + _hs_q = (UT_hash_handle*)((_hs_q->next) ? \ + ((void*)((char*)(_hs_q->next) + \ + (head)->hh.tbl->hho)) : NULL); \ + _hs_qsize--; \ + } else if ( (_hs_qsize == 0) || !(_hs_q) ) { \ + _hs_e = _hs_p; \ + _hs_p = (UT_hash_handle*)((_hs_p->next) ? \ + ((void*)((char*)(_hs_p->next) + \ + (head)->hh.tbl->hho)) : NULL); \ + _hs_psize--; \ + } else if (( \ + cmpfcn(DECLTYPE(head)(ELMT_FROM_HH((head)->hh.tbl,_hs_p)), \ + DECLTYPE(head)(ELMT_FROM_HH((head)->hh.tbl,_hs_q))) \ + ) <= 0) { \ + _hs_e = _hs_p; \ + _hs_p = (UT_hash_handle*)((_hs_p->next) ? \ + ((void*)((char*)(_hs_p->next) + \ + (head)->hh.tbl->hho)) : NULL); \ + _hs_psize--; \ + } else { \ + _hs_e = _hs_q; \ + _hs_q = (UT_hash_handle*)((_hs_q->next) ? \ + ((void*)((char*)(_hs_q->next) + \ + (head)->hh.tbl->hho)) : NULL); \ + _hs_qsize--; \ + } \ + if ( _hs_tail ) { \ + _hs_tail->next = ((_hs_e) ? \ + ELMT_FROM_HH((head)->hh.tbl,_hs_e) : NULL); \ + } else { \ + _hs_list = _hs_e; \ + } \ + _hs_e->prev = ((_hs_tail) ? \ + ELMT_FROM_HH((head)->hh.tbl,_hs_tail) : NULL); \ + _hs_tail = _hs_e; \ + } \ + _hs_p = _hs_q; \ + } \ + _hs_tail->next = NULL; \ + if ( _hs_nmerges <= 1 ) { \ + _hs_looping=0; \ + (head)->hh.tbl->tail = _hs_tail; \ + DECLTYPE_ASSIGN(head,ELMT_FROM_HH((head)->hh.tbl, _hs_list)); \ + } \ + _hs_insize *= 2; \ + } \ + HASH_FSCK(hh,head); \ + } \ +} while (0) + +/* This function selects items from one hash into another hash. + * The end result is that the selected items have dual presence + * in both hashes. There is no copy of the items made; rather + * they are added into the new hash through a secondary hash + * hash handle that must be present in the structure. */ +#define HASH_SELECT(hh_dst, dst, hh_src, src, cond) \ +do { \ + unsigned _src_bkt, _dst_bkt; \ + void *_last_elt=NULL, *_elt; \ + UT_hash_handle *_src_hh, *_dst_hh, *_last_elt_hh=NULL; \ + ptrdiff_t _dst_hho = ((char*)(&(dst)->hh_dst) - (char*)(dst)); \ + if (src) { \ + for(_src_bkt=0; _src_bkt < (src)->hh_src.tbl->num_buckets; _src_bkt++) { \ + for(_src_hh = (src)->hh_src.tbl->buckets[_src_bkt].hh_head; \ + _src_hh; \ + _src_hh = _src_hh->hh_next) { \ + _elt = ELMT_FROM_HH((src)->hh_src.tbl, _src_hh); \ + if (cond(_elt)) { \ + _dst_hh = (UT_hash_handle*)(((char*)_elt) + _dst_hho); \ + _dst_hh->key = _src_hh->key; \ + _dst_hh->keylen = _src_hh->keylen; \ + _dst_hh->hashv = _src_hh->hashv; \ + _dst_hh->prev = _last_elt; \ + _dst_hh->next = NULL; \ + if (_last_elt_hh) { _last_elt_hh->next = _elt; } \ + if (!dst) { \ + DECLTYPE_ASSIGN(dst,_elt); \ + HASH_MAKE_TABLE(hh_dst,dst); \ + } else { \ + _dst_hh->tbl = (dst)->hh_dst.tbl; \ + } \ + HASH_TO_BKT(_dst_hh->hashv, _dst_hh->tbl->num_buckets, _dst_bkt); \ + HASH_ADD_TO_BKT(_dst_hh->tbl->buckets[_dst_bkt],_dst_hh); \ + (dst)->hh_dst.tbl->num_items++; \ + _last_elt = _elt; \ + _last_elt_hh = _dst_hh; \ + } \ + } \ + } \ + } \ + HASH_FSCK(hh_dst,dst); \ +} while (0) + +#define HASH_CLEAR(hh,head) \ +do { \ + if (head) { \ + uthash_free((head)->hh.tbl->buckets, \ + (head)->hh.tbl->num_buckets*sizeof(struct UT_hash_bucket)); \ + HASH_BLOOM_FREE((head)->hh.tbl); \ + uthash_free((head)->hh.tbl, sizeof(UT_hash_table)); \ + (head)=NULL; \ + } \ +} while(0) + +#ifdef NO_DECLTYPE +#define HASH_ITER(hh,head,el,tmp) \ +for((el)=(head), (*(char**)(&(tmp)))=(char*)((head)?(head)->hh.next:NULL); \ + el; (el)=(tmp),(*(char**)(&(tmp)))=(char*)((tmp)?(tmp)->hh.next:NULL)) +#else +#define HASH_ITER(hh,head,el,tmp) \ +for((el)=(head),(tmp)=DECLTYPE(el)((head)?(head)->hh.next:NULL); \ + el; (el)=(tmp),(tmp)=DECLTYPE(el)((tmp)?(tmp)->hh.next:NULL)) +#endif + +/* obtain a count of items in the hash */ +#define HASH_COUNT(head) HASH_CNT(hh,head) +#define HASH_CNT(hh,head) ((head)?((head)->hh.tbl->num_items):0) + +typedef struct UT_hash_bucket { + struct UT_hash_handle *hh_head; + unsigned count; + + /* expand_mult is normally set to 0. In this situation, the max chain length + * threshold is enforced at its default value, HASH_BKT_CAPACITY_THRESH. (If + * the bucket's chain exceeds this length, bucket expansion is triggered). + * However, setting expand_mult to a non-zero value delays bucket expansion + * (that would be triggered by additions to this particular bucket) + * until its chain length reaches a *multiple* of HASH_BKT_CAPACITY_THRESH. + * (The multiplier is simply expand_mult+1). The whole idea of this + * multiplier is to reduce bucket expansions, since they are expensive, in + * situations where we know that a particular bucket tends to be overused. + * It is better to let its chain length grow to a longer yet-still-bounded + * value, than to do an O(n) bucket expansion too often. + */ + unsigned expand_mult; + +} UT_hash_bucket; + +/* random signature used only to find hash tables in external analysis */ +#define HASH_SIGNATURE 0xa0111fe1 +#define HASH_BLOOM_SIGNATURE 0xb12220f2 + +typedef struct UT_hash_table { + UT_hash_bucket *buckets; + unsigned num_buckets, log2_num_buckets; + unsigned num_items; + struct UT_hash_handle *tail; /* tail hh in app order, for fast append */ + ptrdiff_t hho; /* hash handle offset (byte pos of hash handle in element */ + + /* in an ideal situation (all buckets used equally), no bucket would have + * more than ceil(#items/#buckets) items. that's the ideal chain length. */ + unsigned ideal_chain_maxlen; + + /* nonideal_items is the number of items in the hash whose chain position + * exceeds the ideal chain maxlen. these items pay the penalty for an uneven + * hash distribution; reaching them in a chain traversal takes >ideal steps */ + unsigned nonideal_items; + + /* ineffective expands occur when a bucket doubling was performed, but + * afterward, more than half the items in the hash had nonideal chain + * positions. If this happens on two consecutive expansions we inhibit any + * further expansion, as it's not helping; this happens when the hash + * function isn't a good fit for the key domain. When expansion is inhibited + * the hash will still work, albeit no longer in constant time. */ + unsigned ineff_expands, noexpand; + + uint32_t signature; /* used only to find hash tables in external analysis */ +#ifdef HASH_BLOOM + uint32_t bloom_sig; /* used only to test bloom exists in external analysis */ + uint8_t *bloom_bv; + char bloom_nbits; +#endif + +} UT_hash_table; + +typedef struct UT_hash_handle { + struct UT_hash_table *tbl; + void *prev; /* prev element in app order */ + void *next; /* next element in app order */ + struct UT_hash_handle *hh_prev; /* previous hh in bucket order */ + struct UT_hash_handle *hh_next; /* next hh in bucket order */ + void *key; /* ptr to enclosing struct's key */ + unsigned keylen; /* enclosing struct's key len */ + unsigned hashv; /* result of hash-fcn(key) */ +} UT_hash_handle; + +#endif /* UTHASH_H */ diff --git a/rebar b/rebar new file mode 100755 index 0000000..44053a5 Binary files /dev/null and b/rebar differ diff --git a/rebar.config b/rebar.config new file mode 100644 index 0000000..88ac957 --- /dev/null +++ b/rebar.config @@ -0,0 +1,17 @@ +%% -*- erlang -*- + +{erl_opts, [ + debug_info, + warnings_as_errors, + warn_export_all +]}. + +{port_specs, [ + {"unix", "priv/emdb_drv.so", ["c_src/*.c"]}, + {"darwin", "priv/emdb_drv.so", ["c_src/*.c"]}, + {"win32", "priv/emdb_drv.dll", ["c_src/*.c"]} + ]}. + +{port_env, [ + {".*", "CFLAGS", "-O2 -Wall"} +]}. diff --git a/src/emdb.app.src b/src/emdb.app.src new file mode 100644 index 0000000..6c37ce2 --- /dev/null +++ b/src/emdb.app.src @@ -0,0 +1,11 @@ +{application, emdb, + [ + {description, "Memory-Mapped Database"}, + {vsn, "0.9.0"}, + {registered, []}, + {applications, [ + kernel, + stdlib + ]}, + {env, []} + ]}. diff --git a/src/emdb.erl b/src/emdb.erl new file mode 100644 index 0000000..8b0a844 --- /dev/null +++ b/src/emdb.erl @@ -0,0 +1,73 @@ +%%------------------------------------------------------------------- +%% This file is part of EMDB - Erlang MDB API +%% +%% Copyright (c) 2012 by Aleph Archives. All rights reserved. +%% +%%------------------------------------------------------------------- +%% Redistribution and use in source and binary forms, with or without +%% modification, are permitted only as authorized by the OpenLDAP +%% Public License. +%% +%% A copy of this license is available in the file LICENSE in the +%% top-level directory of the distribution or, alternatively, at +%% . +%% +%% Permission to use, copy, modify, and distribute this software for any +%% purpose with or without fee is hereby granted, provided that the above +%% copyright notice and this permission notice appear in all copies. +%% +%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +%%------------------------------------------------------------------- + +-module(emdb). + + +%%==================================================================== +%% EXPORTS +%%==================================================================== +-export([ + open/1 + ]). + + +%%==================================================================== +%% Types +%%==================================================================== +-record(emdb_oop, { + handle :: non_neg_integer() + }). + + + +%%==================================================================== +%% PUBLIC API +%%==================================================================== + +%%-------------------------------------------------------------------- +%% @doc Create a new MDB database +%% @end +%%-------------------------------------------------------------------- +-spec open(file:name()) -> #emdb_oop{}. +open(DirName) -> + %% ensure directory exists + ok = filelib:ensure_dir(DirName ++ "/"), + decorate(emdb_drv:open(DirName)). + + +%%==================================================================== +%% PRIVATE API +%%==================================================================== + +%% @private +decorate({ok, Handle}) -> + CDB = emdb_oop:new(Handle), + {ok, CDB}; + +decorate(Error) -> + Error. diff --git a/src/emdb_drv.erl b/src/emdb_drv.erl new file mode 100644 index 0000000..6315a5a --- /dev/null +++ b/src/emdb_drv.erl @@ -0,0 +1,137 @@ +%%------------------------------------------------------------------- +%% This file is part of EMDB - Erlang MDB API +%% +%% Copyright (c) 2012 by Aleph Archives. All rights reserved. +%% +%%------------------------------------------------------------------- +%% Redistribution and use in source and binary forms, with or without +%% modification, are permitted only as authorized by the OpenLDAP +%% Public License. +%% +%% A copy of this license is available in the file LICENSE in the +%% top-level directory of the distribution or, alternatively, at +%% . +%% +%% Permission to use, copy, modify, and distribute this software for any +%% purpose with or without fee is hereby granted, provided that the above +%% copyright notice and this permission notice appear in all copies. +%% +%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +%%------------------------------------------------------------------- + +-module(emdb_drv). + +%%==================================================================== +%% EXPORTS +%%==================================================================== +-export([ + open/1, + close/1, + + put/3, + get/2, + del/2, + + update/3, + + drop/1 + ]). + + +%% internal export (ex. spawn, apply) +-on_load(init/0). + +%%==================================================================== +%% MACROS +%%==================================================================== +-define(EMDB_DRIVER_NAME, "emdb_drv"). +-define(NOT_LOADED, not_loaded(?LINE)). + + +%%==================================================================== +%% PUBLIC API +%%==================================================================== + +%%-------------------------------------------------------------------- +%% @doc +%% @end +%%-------------------------------------------------------------------- +open(_DirName) -> + ?NOT_LOADED. + +%%-------------------------------------------------------------------- +%% @doc +%% @end +%%-------------------------------------------------------------------- +close(_Handle) -> + ?NOT_LOADED. + +%%-------------------------------------------------------------------- +%% @doc +%% @end +%%-------------------------------------------------------------------- +put(_Handle, _Key, _Val) -> + ?NOT_LOADED. + + +%%-------------------------------------------------------------------- +%% @doc +%% @end +%%-------------------------------------------------------------------- +get(_Handle, _Key) -> + ?NOT_LOADED. + +%%-------------------------------------------------------------------- +%% @doc +%% @end +%%-------------------------------------------------------------------- +del(_Handle, _Key) -> + ?NOT_LOADED. + + +%%-------------------------------------------------------------------- +%% @doc +%% @end +%%-------------------------------------------------------------------- +update(_Handle, _Key, _Val) -> + ?NOT_LOADED. + +%%-------------------------------------------------------------------- +%% @doc +%% @end +%%-------------------------------------------------------------------- +drop(_Handle) -> + ?NOT_LOADED. + +%%==================================================================== +%% PRIVATE API +%%==================================================================== + +%%-------------------------------------------------------------------- +%% @doc +%% @end +%%-------------------------------------------------------------------- +init() -> + PrivDir = case code:priv_dir(?MODULE) of + {error, _} -> + EbinDir = filename:dirname(code:which(?MODULE)), + AppPath = filename:dirname(EbinDir), + filename:join(AppPath, "priv"); + Path -> + Path + end, + erlang:load_nif(filename:join(PrivDir, ?EMDB_DRIVER_NAME), 0). + + +%%-------------------------------------------------------------------- +%% @doc +%% @end +%%-------------------------------------------------------------------- +not_loaded(Line) -> + erlang:nif_error({not_loaded, [{module, ?MODULE}, {line, Line}]}). diff --git a/src/emdb_oop.erl b/src/emdb_oop.erl new file mode 100644 index 0000000..800672b --- /dev/null +++ b/src/emdb_oop.erl @@ -0,0 +1,97 @@ +%%------------------------------------------------------------------- +%% This file is part of EMDB - Erlang MDB API +%% +%% Copyright (c) 2012 by Aleph Archives. All rights reserved. +%% +%%------------------------------------------------------------------- +%% Redistribution and use in source and binary forms, with or without +%% modification, are permitted only as authorized by the OpenLDAP +%% Public License. +%% +%% A copy of this license is available in the file LICENSE in the +%% top-level directory of the distribution or, alternatively, at +%% . +%% +%% Permission to use, copy, modify, and distribute this software for any +%% purpose with or without fee is hereby granted, provided that the above +%% copyright notice and this permission notice appear in all copies. +%% +%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +%%------------------------------------------------------------------- + +-module(emdb_oop, [Handle]). + + +%%==================================================================== +%% EXPORTS +%%==================================================================== +-export([ + close/0, + + put/2, + get/1, + del/1, + + update/2, + + drop/0 + ]). + + +%%==================================================================== +%% PUBLIC API +%%==================================================================== + +%%-------------------------------------------------------------------- +%% @doc +%% @end +%%-------------------------------------------------------------------- +close() -> + emdb_drv:close(Handle). + +%%-------------------------------------------------------------------- +%% @doc +%% @end +%%-------------------------------------------------------------------- +put(Key, Val) when is_binary(Key) andalso is_binary(Val) -> + emdb_drv:put(Handle, Key, Val). + + +%%-------------------------------------------------------------------- +%% @doc +%% @end +%%-------------------------------------------------------------------- +get(Key) when is_binary(Key) -> + emdb_drv:get(Handle, Key). + +%%-------------------------------------------------------------------- +%% @doc +%% @end +%%-------------------------------------------------------------------- +del(Key) when is_binary(Key) -> + emdb_drv:del(Handle, Key). + +%%-------------------------------------------------------------------- +%% @doc +%% @end +%%-------------------------------------------------------------------- +update(Key, Val) when is_binary(Key) andalso is_binary(Val) -> + emdb_drv:update(Handle, Key, Val). + + +%%-------------------------------------------------------------------- +%% @doc +%% @end +%%-------------------------------------------------------------------- +drop() -> + emdb_drv:drop(Handle). + +%%==================================================================== +%% INTERNAL FUNCTIONS +%%==================================================================== diff --git a/start.sh b/start.sh new file mode 100755 index 0000000..9e81aa4 --- /dev/null +++ b/start.sh @@ -0,0 +1,4 @@ +#!/usr/bin/env bash + +cd `dirname $0` +exec erl -pa $PWD/ebin -pa +B -- $@