mirror of
https://github.com/berkeleydb/libdb.git
synced 2024-11-17 09:36:24 +00:00
113 lines
4 KiB
C
113 lines
4 KiB
C
|
/*
|
||
|
|
** 2001 September 22
|
||
|
|
**
|
||
|
|
** The author disclaims copyright to this source code. In place of
|
||
|
|
** a legal notice, here is a blessing:
|
||
|
|
**
|
||
|
|
** May you do good and not evil.
|
||
|
|
** May you find forgiveness for yourself and forgive others.
|
||
|
|
** May you share freely, never taking more than you give.
|
||
|
|
**
|
||
|
|
*************************************************************************
|
||
|
|
** This is the header file for the generic hash-table implemenation
|
||
|
|
** used in SQLite. We've modified it slightly to serve as a standalone
|
||
|
|
** hash table implementation for the full-text indexing module.
|
||
|
|
**
|
||
|
|
*/
|
||
|
|
#ifndef _FTS1_HASH_H_
|
||
|
|
#define _FTS1_HASH_H_
|
||
|
|
|
||
|
|
/* Forward declarations of structures. */
|
||
|
|
typedef struct fts1Hash fts1Hash;
|
||
|
|
typedef struct fts1HashElem fts1HashElem;
|
||
|
|
|
||
|
|
/* A complete hash table is an instance of the following structure.
|
||
|
|
** The internals of this structure are intended to be opaque -- client
|
||
|
|
** code should not attempt to access or modify the fields of this structure
|
||
|
|
** directly. Change this structure only by using the routines below.
|
||
|
|
** However, many of the "procedures" and "functions" for modifying and
|
||
|
|
** accessing this structure are really macros, so we can't really make
|
||
|
|
** this structure opaque.
|
||
|
|
*/
|
||
|
|
struct fts1Hash {
|
||
|
|
char keyClass; /* HASH_INT, _POINTER, _STRING, _BINARY */
|
||
|
|
char copyKey; /* True if copy of key made on insert */
|
||
|
|
int count; /* Number of entries in this table */
|
||
|
|
fts1HashElem *first; /* The first element of the array */
|
||
|
|
void *(*xMalloc)(int); /* malloc() function to use */
|
||
|
|
void (*xFree)(void *); /* free() function to use */
|
||
|
|
int htsize; /* Number of buckets in the hash table */
|
||
|
|
struct _fts1ht { /* the hash table */
|
||
|
|
int count; /* Number of entries with this hash */
|
||
|
|
fts1HashElem *chain; /* Pointer to first entry with this hash */
|
||
|
|
} *ht;
|
||
|
|
};
|
||
|
|
|
||
|
|
/* Each element in the hash table is an instance of the following
|
||
|
|
** structure. All elements are stored on a single doubly-linked list.
|
||
|
|
**
|
||
|
|
** Again, this structure is intended to be opaque, but it can't really
|
||
|
|
** be opaque because it is used by macros.
|
||
|
|
*/
|
||
|
|
struct fts1HashElem {
|
||
|
|
fts1HashElem *next, *prev; /* Next and previous elements in the table */
|
||
|
|
void *data; /* Data associated with this element */
|
||
|
|
void *pKey; int nKey; /* Key associated with this element */
|
||
|
|
};
|
||
|
|
|
||
|
|
/*
|
||
|
|
** There are 2 different modes of operation for a hash table:
|
||
|
|
**
|
||
|
|
** FTS1_HASH_STRING pKey points to a string that is nKey bytes long
|
||
|
|
** (including the null-terminator, if any). Case
|
||
|
|
** is respected in comparisons.
|
||
|
|
**
|
||
|
|
** FTS1_HASH_BINARY pKey points to binary data nKey bytes long.
|
||
|
|
** memcmp() is used to compare keys.
|
||
|
|
**
|
||
|
|
** A copy of the key is made if the copyKey parameter to fts1HashInit is 1.
|
||
|
|
*/
|
||
|
|
#define FTS1_HASH_STRING 1
|
||
|
|
#define FTS1_HASH_BINARY 2
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Access routines. To delete, insert a NULL pointer.
|
||
|
|
*/
|
||
|
|
void sqlite3Fts1HashInit(fts1Hash*, int keytype, int copyKey);
|
||
|
|
void *sqlite3Fts1HashInsert(fts1Hash*, const void *pKey, int nKey, void *pData);
|
||
|
|
void *sqlite3Fts1HashFind(const fts1Hash*, const void *pKey, int nKey);
|
||
|
|
void sqlite3Fts1HashClear(fts1Hash*);
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Shorthand for the functions above
|
||
|
|
*/
|
||
|
|
#define fts1HashInit sqlite3Fts1HashInit
|
||
|
|
#define fts1HashInsert sqlite3Fts1HashInsert
|
||
|
|
#define fts1HashFind sqlite3Fts1HashFind
|
||
|
|
#define fts1HashClear sqlite3Fts1HashClear
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Macros for looping over all elements of a hash table. The idiom is
|
||
|
|
** like this:
|
||
|
|
**
|
||
|
|
** fts1Hash h;
|
||
|
|
** fts1HashElem *p;
|
||
|
|
** ...
|
||
|
|
** for(p=fts1HashFirst(&h); p; p=fts1HashNext(p)){
|
||
|
|
** SomeStructure *pData = fts1HashData(p);
|
||
|
|
** // do something with pData
|
||
|
|
** }
|
||
|
|
*/
|
||
|
|
#define fts1HashFirst(H) ((H)->first)
|
||
|
|
#define fts1HashNext(E) ((E)->next)
|
||
|
|
#define fts1HashData(E) ((E)->data)
|
||
|
|
#define fts1HashKey(E) ((E)->pKey)
|
||
|
|
#define fts1HashKeysize(E) ((E)->nKey)
|
||
|
|
|
||
|
|
/*
|
||
|
|
** Number of entries in a hash table
|
||
|
|
*/
|
||
|
|
#define fts1HashCount(H) ((H)->count)
|
||
|
|
|
||
|
|
#endif /* _FTS1_HASH_H_ */
|