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Diffstat (limited to 'chromium/third_party/sqlite/sqlite-src-3240000/src/memjournal.c')
| -rw-r--r-- | chromium/third_party/sqlite/sqlite-src-3240000/src/memjournal.c | 434 |
1 files changed, 0 insertions, 434 deletions
diff --git a/chromium/third_party/sqlite/sqlite-src-3240000/src/memjournal.c b/chromium/third_party/sqlite/sqlite-src-3240000/src/memjournal.c deleted file mode 100644 index 3b0e7a67286..00000000000 --- a/chromium/third_party/sqlite/sqlite-src-3240000/src/memjournal.c +++ /dev/null @@ -1,434 +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. -** -** Update: The in-memory journal is also used to temporarily cache -** smaller journals that are not critical for power-loss recovery. -** For example, statement journals that are not too big will be held -** entirely in memory, thus reducing the number of file I/O calls, and -** more importantly, reducing temporary file creation events. If these -** journals become too large for memory, they are spilled to disk. But -** in the common case, they are usually small and no file I/O needs to -** occur. -*/ -#include "sqliteInt.h" - -/* Forward references to internal structures */ -typedef struct MemJournal MemJournal; -typedef struct FilePoint FilePoint; -typedef struct FileChunk FileChunk; - -/* -** The rollback journal is composed of a linked list of these structures. -** -** The zChunk array is always at least 8 bytes in size - usually much more. -** Its actual size is stored in the MemJournal.nChunkSize variable. -*/ -struct FileChunk { - FileChunk *pNext; /* Next chunk in the journal */ - u8 zChunk[8]; /* Content of this chunk */ -}; - -/* -** By default, allocate this many bytes of memory for each FileChunk object. -*/ -#define MEMJOURNAL_DFLT_FILECHUNKSIZE 1024 - -/* -** For chunk size nChunkSize, return the number of bytes that should -** be allocated for each FileChunk structure. -*/ -#define fileChunkSize(nChunkSize) (sizeof(FileChunk) + ((nChunkSize)-8)) - -/* -** 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 structure is a subclass of sqlite3_file. Each open memory-journal -** is an instance of this class. -*/ -struct MemJournal { - const sqlite3_io_methods *pMethod; /* Parent class. MUST BE FIRST */ - int nChunkSize; /* In-memory chunk-size */ - - int nSpill; /* Bytes of data before flushing */ - int nSize; /* Bytes of data currently in memory */ - 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() */ - - int flags; /* xOpen flags */ - sqlite3_vfs *pVfs; /* The "real" underlying VFS */ - const char *zJournal; /* Name of the journal file */ -}; - -/* -** 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; - -#if defined(SQLITE_ENABLE_ATOMIC_WRITE) \ - || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE) - if( (iAmt+iOfst)>p->endpoint.iOffset ){ - return SQLITE_IOERR_SHORT_READ; - } -#endif - - assert( (iAmt+iOfst)<=p->endpoint.iOffset ); - assert( p->readpoint.iOffset==0 || p->readpoint.pChunk!=0 ); - if( p->readpoint.iOffset!=iOfst || iOfst==0 ){ - sqlite3_int64 iOff = 0; - for(pChunk=p->pFirst; - ALWAYS(pChunk) && (iOff+p->nChunkSize)<=iOfst; - pChunk=pChunk->pNext - ){ - iOff += p->nChunkSize; - } - }else{ - pChunk = p->readpoint.pChunk; - assert( pChunk!=0 ); - } - - iChunkOffset = (int)(iOfst%p->nChunkSize); - do { - int iSpace = p->nChunkSize - iChunkOffset; - int nCopy = MIN(nRead, (p->nChunkSize - iChunkOffset)); - memcpy(zOut, (u8*)pChunk->zChunk + iChunkOffset, nCopy); - zOut += nCopy; - nRead -= iSpace; - iChunkOffset = 0; - } while( nRead>=0 && (pChunk=pChunk->pNext)!=0 && nRead>0 ); - p->readpoint.iOffset = pChunk ? iOfst+iAmt : 0; - p->readpoint.pChunk = pChunk; - - return SQLITE_OK; -} - -/* -** Free the list of FileChunk structures headed at MemJournal.pFirst. -*/ -static void memjrnlFreeChunks(MemJournal *p){ - FileChunk *pIter; - FileChunk *pNext; - for(pIter=p->pFirst; pIter; pIter=pNext){ - pNext = pIter->pNext; - sqlite3_free(pIter); - } - p->pFirst = 0; -} - -/* -** Flush the contents of memory to a real file on disk. -*/ -static int memjrnlCreateFile(MemJournal *p){ - int rc; - sqlite3_file *pReal = (sqlite3_file*)p; - MemJournal copy = *p; - - memset(p, 0, sizeof(MemJournal)); - rc = sqlite3OsOpen(copy.pVfs, copy.zJournal, pReal, copy.flags, 0); - if( rc==SQLITE_OK ){ - int nChunk = copy.nChunkSize; - i64 iOff = 0; - FileChunk *pIter; - for(pIter=copy.pFirst; pIter; pIter=pIter->pNext){ - if( iOff + nChunk > copy.endpoint.iOffset ){ - nChunk = copy.endpoint.iOffset - iOff; - } - rc = sqlite3OsWrite(pReal, (u8*)pIter->zChunk, nChunk, iOff); - if( rc ) break; - iOff += nChunk; - } - if( rc==SQLITE_OK ){ - /* No error has occurred. Free the in-memory buffers. */ - memjrnlFreeChunks(©); - } - } - if( rc!=SQLITE_OK ){ - /* If an error occurred while creating or writing to the file, restore - ** the original before returning. This way, SQLite uses the in-memory - ** journal data to roll back changes made to the internal page-cache - ** before this function was called. */ - sqlite3OsClose(pReal); - *p = copy; - } - return rc; -} - - -/* -** 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; - - /* If the file should be created now, create it and write the new data - ** into the file on disk. */ - if( p->nSpill>0 && (iAmt+iOfst)>p->nSpill ){ - int rc = memjrnlCreateFile(p); - if( rc==SQLITE_OK ){ - rc = sqlite3OsWrite(pJfd, zBuf, iAmt, iOfst); - } - return rc; - } - - /* If the contents of this write should be stored in memory */ - else{ - /* An in-memory journal file should only ever be appended to. Random - ** access writes are not required. The only exception to this is when - ** the in-memory journal is being used by a connection using the - ** atomic-write optimization. In this case the first 28 bytes of the - ** journal file may be written as part of committing the transaction. */ - assert( iOfst==p->endpoint.iOffset || iOfst==0 ); -#if defined(SQLITE_ENABLE_ATOMIC_WRITE) \ - || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE) - if( iOfst==0 && p->pFirst ){ - assert( p->nChunkSize>iAmt ); - memcpy((u8*)p->pFirst->zChunk, zBuf, iAmt); - }else -#else - assert( iOfst>0 || p->pFirst==0 ); -#endif - { - while( nWrite>0 ){ - FileChunk *pChunk = p->endpoint.pChunk; - int iChunkOffset = (int)(p->endpoint.iOffset%p->nChunkSize); - int iSpace = MIN(nWrite, p->nChunkSize - iChunkOffset); - - if( iChunkOffset==0 ){ - /* New chunk is required to extend the file. */ - FileChunk *pNew = sqlite3_malloc(fileChunkSize(p->nChunkSize)); - if( !pNew ){ - return SQLITE_IOERR_NOMEM_BKPT; - } - pNew->pNext = 0; - if( pChunk ){ - assert( p->pFirst ); - pChunk->pNext = pNew; - }else{ - assert( !p->pFirst ); - p->pFirst = pNew; - } - p->endpoint.pChunk = pNew; - } - - memcpy((u8*)p->endpoint.pChunk->zChunk + iChunkOffset, zWrite, iSpace); - zWrite += iSpace; - nWrite -= iSpace; - p->endpoint.iOffset += iSpace; - } - p->nSize = iAmt + iOfst; - } - } - - return SQLITE_OK; -} - -/* -** Truncate the file. -** -** If the journal file is already on disk, truncate it there. Or, if it -** is still in main memory but is being truncated to zero bytes in size, -** ignore -*/ -static int memjrnlTruncate(sqlite3_file *pJfd, sqlite_int64 size){ - MemJournal *p = (MemJournal *)pJfd; - if( ALWAYS(size==0) ){ - memjrnlFreeChunks(p); - p->nSize = 0; - p->endpoint.pChunk = 0; - p->endpoint.iOffset = 0; - p->readpoint.pChunk = 0; - p->readpoint.iOffset = 0; - } - return SQLITE_OK; -} - -/* -** Close the file. -*/ -static int memjrnlClose(sqlite3_file *pJfd){ - MemJournal *p = (MemJournal *)pJfd; - memjrnlFreeChunks(p); - return SQLITE_OK; -} - -/* -** Sync the file. -** -** If the real file has been created, call its xSync method. Otherwise, -** syncing an in-memory journal is a no-op. -*/ -static int memjrnlSync(sqlite3_file *pJfd, int flags){ - UNUSED_PARAMETER2(pJfd, flags); - return SQLITE_OK; -} - -/* -** 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 const 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 */ - 0, /* xShmMap */ - 0, /* xShmLock */ - 0, /* xShmBarrier */ - 0, /* xShmUnmap */ - 0, /* xFetch */ - 0 /* xUnfetch */ -}; - -/* -** Open a journal file. -** -** The behaviour of the journal file depends on the value of parameter -** nSpill. If nSpill is 0, then the journal file is always create and -** accessed using the underlying VFS. If nSpill is less than zero, then -** all content is always stored in main-memory. Finally, if nSpill is a -** positive value, then the journal file is initially created in-memory -** but may be flushed to disk later on. In this case the journal file is -** flushed to disk either when it grows larger than nSpill bytes in size, -** or when sqlite3JournalCreate() is called. -*/ -int sqlite3JournalOpen( - sqlite3_vfs *pVfs, /* The VFS to use for actual file I/O */ - const char *zName, /* Name of the journal file */ - sqlite3_file *pJfd, /* Preallocated, blank file handle */ - int flags, /* Opening flags */ - int nSpill /* Bytes buffered before opening the file */ -){ - MemJournal *p = (MemJournal*)pJfd; - - /* Zero the file-handle object. If nSpill was passed zero, initialize - ** it using the sqlite3OsOpen() function of the underlying VFS. In this - ** case none of the code in this module is executed as a result of calls - ** made on the journal file-handle. */ - memset(p, 0, sizeof(MemJournal)); - if( nSpill==0 ){ - return sqlite3OsOpen(pVfs, zName, pJfd, flags, 0); - } - - if( nSpill>0 ){ - p->nChunkSize = nSpill; - }else{ - p->nChunkSize = 8 + MEMJOURNAL_DFLT_FILECHUNKSIZE - sizeof(FileChunk); - assert( MEMJOURNAL_DFLT_FILECHUNKSIZE==fileChunkSize(p->nChunkSize) ); - } - - p->pMethod = (const sqlite3_io_methods*)&MemJournalMethods; - p->nSpill = nSpill; - p->flags = flags; - p->zJournal = zName; - p->pVfs = pVfs; - return SQLITE_OK; -} - -/* -** Open an in-memory journal file. -*/ -void sqlite3MemJournalOpen(sqlite3_file *pJfd){ - sqlite3JournalOpen(0, 0, pJfd, 0, -1); -} - -#if defined(SQLITE_ENABLE_ATOMIC_WRITE) \ - || defined(SQLITE_ENABLE_BATCH_ATOMIC_WRITE) -/* -** If the argument p points to a MemJournal structure that is not an -** in-memory-only journal file (i.e. is one that was opened with a +ve -** nSpill parameter or as SQLITE_OPEN_MAIN_JOURNAL), and the underlying -** file has not yet been created, create it now. -*/ -int sqlite3JournalCreate(sqlite3_file *pJfd){ - int rc = SQLITE_OK; - MemJournal *p = (MemJournal*)pJfd; - if( p->pMethod==&MemJournalMethods && ( -#ifdef SQLITE_ENABLE_ATOMIC_WRITE - p->nSpill>0 -#else - /* While this appears to not be possible without ATOMIC_WRITE, the - ** paths are complex, so it seems prudent to leave the test in as - ** a NEVER(), in case our analysis is subtly flawed. */ - NEVER(p->nSpill>0) -#endif -#ifdef SQLITE_ENABLE_BATCH_ATOMIC_WRITE - || (p->flags & SQLITE_OPEN_MAIN_JOURNAL) -#endif - )){ - rc = memjrnlCreateFile(p); - } - return rc; -} -#endif - -/* -** The file-handle passed as the only argument is open on a journal file. -** Return true if this "journal file" is currently stored in heap memory, -** or false otherwise. -*/ -int sqlite3JournalIsInMemory(sqlite3_file *p){ - return p->pMethods==&MemJournalMethods; -} - -/* -** Return the number of bytes required to store a JournalFile that uses vfs -** pVfs to create the underlying on-disk files. -*/ -int sqlite3JournalSize(sqlite3_vfs *pVfs){ - return MAX(pVfs->szOsFile, (int)sizeof(MemJournal)); -} |