191 lines
6.2 KiB
C
191 lines
6.2 KiB
C
/*---
|
|
This software is copyrighted by the Regents of the University of
|
|
California, and other parties. The following terms apply to all files
|
|
associated with the software unless explicitly disclaimed in
|
|
individual files.
|
|
|
|
The authors hereby grant permission to use, copy, modify, distribute,
|
|
and license this software and its documentation for any purpose,
|
|
provided that existing copyright notices are retained in all copies
|
|
and that this notice is included verbatim in any distributions. No
|
|
written agreement, license, or royalty fee is required for any of the
|
|
authorized uses. Modifications to this software may be copyrighted by
|
|
their authors and need not follow the licensing terms described here,
|
|
provided that the new terms are clearly indicated on the first page of
|
|
each file where they apply.
|
|
|
|
IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY
|
|
FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
|
|
ARISING OUT OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION, OR ANY
|
|
DERIVATIVES THEREOF, EVEN IF THE AUTHORS HAVE BEEN ADVISED OF THE
|
|
POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES,
|
|
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
|
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND
|
|
NON-INFRINGEMENT. THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, AND
|
|
THE AUTHORS AND DISTRIBUTORS HAVE NO OBLIGATION TO PROVIDE
|
|
MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
|
|
|
|
GOVERNMENT USE: If you are acquiring this software on behalf of the
|
|
U.S. government, the Government shall have only "Restricted Rights" in
|
|
the software and related documentation as defined in the Federal
|
|
Acquisition Regulations (FARs) in Clause 52.227.19 (c) (2). If you are
|
|
acquiring the software on behalf of the Department of Defense, the
|
|
software shall be classified as "Commercial Computer Software" and the
|
|
Government shall have only "Restricted Rights" as defined in Clause
|
|
252.227-7013 (c) (1) of DFARs. Notwithstanding the foregoing, the
|
|
authors grant the U.S. Government and others acting in its behalf
|
|
permission to use and distribute the software in accordance with the
|
|
terms specified in this license.
|
|
---*/
|
|
/**
|
|
* @file
|
|
* Manages the page buffer
|
|
|
|
pageManager - Provides cached page handling, delegates to blob
|
|
manager when necessary. Doesn't implement an eviction policy.
|
|
That is left to a cacheManager. (Multiple cacheManagers can be
|
|
used with a single page manager.)
|
|
|
|
|
|
@todo Allow error checking!
|
|
|
|
@todo Make linux provide a better version of malloc(). We need to
|
|
directly DMA pages into and out of userland, or setup mmap() so
|
|
that it takes a flag that makes it page mmapped() pages to swap
|
|
instead of back to disk. (munmap() and msync() would still hit the
|
|
on-disk copy)
|
|
|
|
@todo Refactoring for lock manager
|
|
|
|
Possible interface for lockManager:
|
|
|
|
Define three classes of objects that the lock manager is interested in:
|
|
|
|
Transactions,
|
|
Operations,
|
|
Predicates.
|
|
|
|
LLADD already has operations and transactions, and these can be
|
|
relatively unchanged. Predicates are read only operations that
|
|
return a set of tuples. Tread() is the simplest predicate.
|
|
Index scans provide a motivating example.
|
|
|
|
See http://research.microsoft.com/%7Eadya/pubs/icde00.pdf
|
|
(Generalized Isolation Level Definitions, Adya, Liskov, O'Neil,
|
|
2000) for a theoretical discussion of general locking schemes..
|
|
|
|
Locking functions can return errors such as DEADLOCK, etc.
|
|
When such a value is returned, the transaction aborts, and an
|
|
error is passed up to the application.
|
|
|
|
* @ingroup LLADD_CORE
|
|
* $Id$
|
|
*/
|
|
|
|
#ifndef __BUFFERMANAGER_H__
|
|
#define __BUFFERMANAGER_H__
|
|
|
|
|
|
#include <lladd/constants.h>
|
|
#include <lladd/transactional.h>
|
|
/**
|
|
* initialize buffer manager
|
|
* @return 0 on success
|
|
* @return error code on failure
|
|
*/
|
|
int bufInit();
|
|
|
|
/**
|
|
* allocate a record. This must be done in two phases. The first
|
|
* phase reserves a slot, and produces a log entry. The second phase
|
|
* sets up the slot according to the contents of the log entry.
|
|
*
|
|
* Ralloc implements the first phase.
|
|
*
|
|
* @param xid The active transaction.
|
|
* @param size The size of the new record
|
|
* @return allocated record
|
|
*
|
|
* @see slotRalloc the implementation of the second phase.
|
|
*/
|
|
recordid ralloc(int xid, long size);
|
|
|
|
|
|
/**
|
|
* allocate a record at a given slot. (Useful for recovery.)
|
|
*
|
|
* @see ralloc
|
|
*/
|
|
void slotRalloc(int pageid, lsn_t lsn, recordid rid);
|
|
|
|
/**
|
|
* @param pageid ID of page you want to read
|
|
* @return LSN found on disk
|
|
*/
|
|
long readLSN(int pageid);
|
|
|
|
/**
|
|
* @param xid transaction id @param lsn the lsn that the updated
|
|
* record will reflect. This is needed by recovery, and undo. (The
|
|
* lsn of a page must always increase. Undos are handled by passing
|
|
* in the LSN of the CLR that records the undo.)
|
|
*
|
|
* @param rid recordid where you want to write @param dat data you
|
|
* wish to write
|
|
*/
|
|
void writeRecord(int xid, lsn_t lsn, recordid rid, const void *dat);
|
|
|
|
/**
|
|
* @param xid transaction ID
|
|
* @param rid
|
|
* @param dat buffer for data
|
|
*/
|
|
void readRecord(int xid, recordid rid, void *dat);
|
|
|
|
/**
|
|
* all actions necessary when committing a transaction. Can assume that the log
|
|
* has been written as well as any other actions that do not depend on the
|
|
* buffer manager
|
|
*
|
|
* Basicly, this call is here because we used to do copy on write, and
|
|
* it might be useful when locking is implemented.
|
|
*
|
|
* @param xid transaction ID
|
|
* @param lsn the lsn at which the transaction aborted. (Currently
|
|
* unused, but may be useful for other implementations of the buffer
|
|
* manager.)
|
|
* @return 0 on success
|
|
* @return error code on failure
|
|
*/
|
|
int bufTransCommit(int xid, lsn_t lsn);
|
|
|
|
/**
|
|
*
|
|
* Currently identical to bufTransCommit.
|
|
*
|
|
* @param xid transaction ID
|
|
*
|
|
* @param lsn the lsn at which the transaction aborted. (Currently
|
|
* unused, but may be useful for other implementations of the buffer
|
|
* manager.)
|
|
*
|
|
* @return 0 on success
|
|
*
|
|
* @return error code on failure
|
|
*/
|
|
int bufTransAbort(int xid, lsn_t lsn);
|
|
|
|
/**
|
|
* will write out any dirty pages, assumes that there are no running
|
|
* transactions
|
|
*/
|
|
void bufDeinit();
|
|
|
|
void setSlotType(int pageid, int slot, int type);
|
|
|
|
void addPendingEvent(int pageid);
|
|
void removePendingEvent(int pageid);
|
|
|
|
#endif
|