| Index: third_party/sqlite/src/memjournal.c
|
| ===================================================================
|
| --- third_party/sqlite/src/memjournal.c (revision 56608)
|
| +++ third_party/sqlite/src/memjournal.c (working copy)
|
| @@ -1,259 +0,0 @@
|
| -/*
|
| -** 2008 October 7
|
| -**
|
| -** 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 file contains code use to implement an in-memory rollback journal.
|
| -** The in-memory rollback journal is used to journal transactions for
|
| -** ":memory:" databases and when the journal_mode=MEMORY pragma is used.
|
| -**
|
| -** @(#) $Id: memjournal.c,v 1.12 2009/05/04 11:42:30 danielk1977 Exp $
|
| -*/
|
| -#include "sqliteInt.h"
|
| -
|
| -/* Forward references to internal structures */
|
| -typedef struct MemJournal MemJournal;
|
| -typedef struct FilePoint FilePoint;
|
| -typedef struct FileChunk FileChunk;
|
| -
|
| -/* Space to hold the rollback journal is allocated in increments of
|
| -** this many bytes.
|
| -**
|
| -** The size chosen is a little less than a power of two. That way,
|
| -** the FileChunk object will have a size that almost exactly fills
|
| -** a power-of-two allocation. This mimimizes wasted space in power-of-two
|
| -** memory allocators.
|
| -*/
|
| -#define JOURNAL_CHUNKSIZE ((int)(1024-sizeof(FileChunk*)))
|
| -
|
| -/* Macro to find the minimum of two numeric values.
|
| -*/
|
| -#ifndef MIN
|
| -# define MIN(x,y) ((x)<(y)?(x):(y))
|
| -#endif
|
| -
|
| -/*
|
| -** The rollback journal is composed of a linked list of these structures.
|
| -*/
|
| -struct FileChunk {
|
| - FileChunk *pNext; /* Next chunk in the journal */
|
| - u8 zChunk[JOURNAL_CHUNKSIZE]; /* Content of this chunk */
|
| -};
|
| -
|
| -/*
|
| -** An instance of this object serves as a cursor into the rollback journal.
|
| -** The cursor can be either for reading or writing.
|
| -*/
|
| -struct FilePoint {
|
| - sqlite3_int64 iOffset; /* Offset from the beginning of the file */
|
| - FileChunk *pChunk; /* Specific chunk into which cursor points */
|
| -};
|
| -
|
| -/*
|
| -** This subclass is a subclass of sqlite3_file. Each open memory-journal
|
| -** is an instance of this class.
|
| -*/
|
| -struct MemJournal {
|
| - sqlite3_io_methods *pMethod; /* Parent class. MUST BE FIRST */
|
| - FileChunk *pFirst; /* Head of in-memory chunk-list */
|
| - FilePoint endpoint; /* Pointer to the end of the file */
|
| - FilePoint readpoint; /* Pointer to the end of the last xRead() */
|
| -};
|
| -
|
| -/*
|
| -** Read data from the in-memory journal file. This is the implementation
|
| -** of the sqlite3_vfs.xRead method.
|
| -*/
|
| -static int memjrnlRead(
|
| - sqlite3_file *pJfd, /* The journal file from which to read */
|
| - void *zBuf, /* Put the results here */
|
| - int iAmt, /* Number of bytes to read */
|
| - sqlite_int64 iOfst /* Begin reading at this offset */
|
| -){
|
| - MemJournal *p = (MemJournal *)pJfd;
|
| - u8 *zOut = zBuf;
|
| - int nRead = iAmt;
|
| - int iChunkOffset;
|
| - FileChunk *pChunk;
|
| -
|
| - /* SQLite never tries to read past the end of a rollback journal file */
|
| - assert( iOfst+iAmt<=p->endpoint.iOffset );
|
| -
|
| - if( p->readpoint.iOffset!=iOfst || iOfst==0 ){
|
| - sqlite3_int64 iOff = 0;
|
| - for(pChunk=p->pFirst;
|
| - ALWAYS(pChunk) && (iOff+JOURNAL_CHUNKSIZE)<=iOfst;
|
| - pChunk=pChunk->pNext
|
| - ){
|
| - iOff += JOURNAL_CHUNKSIZE;
|
| - }
|
| - }else{
|
| - pChunk = p->readpoint.pChunk;
|
| - }
|
| -
|
| - iChunkOffset = (int)(iOfst%JOURNAL_CHUNKSIZE);
|
| - do {
|
| - int iSpace = JOURNAL_CHUNKSIZE - iChunkOffset;
|
| - int nCopy = MIN(nRead, (JOURNAL_CHUNKSIZE - iChunkOffset));
|
| - memcpy(zOut, &pChunk->zChunk[iChunkOffset], nCopy);
|
| - zOut += nCopy;
|
| - nRead -= iSpace;
|
| - iChunkOffset = 0;
|
| - } while( nRead>=0 && (pChunk=pChunk->pNext)!=0 && nRead>0 );
|
| - p->readpoint.iOffset = iOfst+iAmt;
|
| - p->readpoint.pChunk = pChunk;
|
| -
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -/*
|
| -** Write data to the file.
|
| -*/
|
| -static int memjrnlWrite(
|
| - sqlite3_file *pJfd, /* The journal file into which to write */
|
| - const void *zBuf, /* Take data to be written from here */
|
| - int iAmt, /* Number of bytes to write */
|
| - sqlite_int64 iOfst /* Begin writing at this offset into the file */
|
| -){
|
| - MemJournal *p = (MemJournal *)pJfd;
|
| - int nWrite = iAmt;
|
| - u8 *zWrite = (u8 *)zBuf;
|
| -
|
| - /* An in-memory journal file should only ever be appended to. Random
|
| - ** access writes are not required by sqlite.
|
| - */
|
| - assert( iOfst==p->endpoint.iOffset );
|
| - UNUSED_PARAMETER(iOfst);
|
| -
|
| - while( nWrite>0 ){
|
| - FileChunk *pChunk = p->endpoint.pChunk;
|
| - int iChunkOffset = (int)(p->endpoint.iOffset%JOURNAL_CHUNKSIZE);
|
| - int iSpace = MIN(nWrite, JOURNAL_CHUNKSIZE - iChunkOffset);
|
| -
|
| - if( iChunkOffset==0 ){
|
| - /* New chunk is required to extend the file. */
|
| - FileChunk *pNew = sqlite3_malloc(sizeof(FileChunk));
|
| - if( !pNew ){
|
| - return SQLITE_IOERR_NOMEM;
|
| - }
|
| - pNew->pNext = 0;
|
| - if( pChunk ){
|
| - assert( p->pFirst );
|
| - pChunk->pNext = pNew;
|
| - }else{
|
| - assert( !p->pFirst );
|
| - p->pFirst = pNew;
|
| - }
|
| - p->endpoint.pChunk = pNew;
|
| - }
|
| -
|
| - memcpy(&p->endpoint.pChunk->zChunk[iChunkOffset], zWrite, iSpace);
|
| - zWrite += iSpace;
|
| - nWrite -= iSpace;
|
| - p->endpoint.iOffset += iSpace;
|
| - }
|
| -
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -/*
|
| -** Truncate the file.
|
| -*/
|
| -static int memjrnlTruncate(sqlite3_file *pJfd, sqlite_int64 size){
|
| - MemJournal *p = (MemJournal *)pJfd;
|
| - FileChunk *pChunk;
|
| - assert(size==0);
|
| - UNUSED_PARAMETER(size);
|
| - pChunk = p->pFirst;
|
| - while( pChunk ){
|
| - FileChunk *pTmp = pChunk;
|
| - pChunk = pChunk->pNext;
|
| - sqlite3_free(pTmp);
|
| - }
|
| - sqlite3MemJournalOpen(pJfd);
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -/*
|
| -** Close the file.
|
| -*/
|
| -static int memjrnlClose(sqlite3_file *pJfd){
|
| - memjrnlTruncate(pJfd, 0);
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -
|
| -/*
|
| -** Sync the file.
|
| -**
|
| -** Syncing an in-memory journal is a no-op. And, in fact, this routine
|
| -** is never called in a working implementation. This implementation
|
| -** exists purely as a contingency, in case some malfunction in some other
|
| -** part of SQLite causes Sync to be called by mistake.
|
| -*/
|
| -static int memjrnlSync(sqlite3_file *NotUsed, int NotUsed2){ /*NO_TEST*/
|
| - UNUSED_PARAMETER2(NotUsed, NotUsed2); /*NO_TEST*/
|
| - assert( 0 ); /*NO_TEST*/
|
| - return SQLITE_OK; /*NO_TEST*/
|
| -} /*NO_TEST*/
|
| -
|
| -/*
|
| -** Query the size of the file in bytes.
|
| -*/
|
| -static int memjrnlFileSize(sqlite3_file *pJfd, sqlite_int64 *pSize){
|
| - MemJournal *p = (MemJournal *)pJfd;
|
| - *pSize = (sqlite_int64) p->endpoint.iOffset;
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -/*
|
| -** Table of methods for MemJournal sqlite3_file object.
|
| -*/
|
| -static struct sqlite3_io_methods MemJournalMethods = {
|
| - 1, /* iVersion */
|
| - memjrnlClose, /* xClose */
|
| - memjrnlRead, /* xRead */
|
| - memjrnlWrite, /* xWrite */
|
| - memjrnlTruncate, /* xTruncate */
|
| - memjrnlSync, /* xSync */
|
| - memjrnlFileSize, /* xFileSize */
|
| - 0, /* xLock */
|
| - 0, /* xUnlock */
|
| - 0, /* xCheckReservedLock */
|
| - 0, /* xFileControl */
|
| - 0, /* xSectorSize */
|
| - 0 /* xDeviceCharacteristics */
|
| -};
|
| -
|
| -/*
|
| -** Open a journal file.
|
| -*/
|
| -void sqlite3MemJournalOpen(sqlite3_file *pJfd){
|
| - MemJournal *p = (MemJournal *)pJfd;
|
| - assert( EIGHT_BYTE_ALIGNMENT(p) );
|
| - memset(p, 0, sqlite3MemJournalSize());
|
| - p->pMethod = &MemJournalMethods;
|
| -}
|
| -
|
| -/*
|
| -** Return true if the file-handle passed as an argument is
|
| -** an in-memory journal
|
| -*/
|
| -int sqlite3IsMemJournal(sqlite3_file *pJfd){
|
| - return pJfd->pMethods==&MemJournalMethods;
|
| -}
|
| -
|
| -/*
|
| -** Return the number of bytes required to store a MemJournal that uses vfs
|
| -** pVfs to create the underlying on-disk files.
|
| -*/
|
| -int sqlite3MemJournalSize(void){
|
| - return sizeof(MemJournal);
|
| -}
|
|
|