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DEFINITIONS
This source file includes following definitions.
- sqlite3SetCrashParams
- crashRequired
- initFile
- closeFile
- osTell
- cacheBlock
- writeCache2
- writeCache
- sqlite3OsClose
- sqlite3OsRead
- sqlite3OsWrite
- sqlite3OsSync
- sqlite3OsTruncate
- sqlite3OsFileSize
- sqlite3OsOpenReadWrite
- sqlite3OsOpenExclusive
- sqlite3OsOpenReadOnly
- sqlite3OsSeek
- sqlite3OsCheckReservedLock
- sqlite3OsLock
- sqlite3OsUnlock
- sqlite3OsOpenDirectory
/*
** 2004 May 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 file contains code that is specific to Unix systems. It is used
** for testing SQLite only.
*/
#if OS_TEST /* This file is used for the test backend only */
#include "sqliteInt.h"
#include "os.h" /* Must be first to enable large file support */
#define sqlite3OsOpenReadWrite sqlite3RealOpenReadWrite
#define sqlite3OsOpenExclusive sqlite3RealOpenExclusive
#define sqlite3OsOpenReadOnly sqlite3RealOpenReadOnly
#define sqlite3OsOpenDirectory sqlite3RealOpenDirectory
#define sqlite3OsClose sqlite3RealClose
#define sqlite3OsRead sqlite3RealRead
#define sqlite3OsWrite sqlite3RealWrite
#define sqlite3OsSeek sqlite3RealSeek
#define sqlite3OsSync sqlite3RealSync
#define sqlite3OsTruncate sqlite3RealTruncate
#define sqlite3OsFileSize sqlite3RealFileSize
#define sqlite3OsLock sqlite3RealLock
#define sqlite3OsUnlock sqlite3RealUnlock
#define sqlite3OsCheckReservedLock sqlite3RealCheckReservedLock
#define OsFile OsRealFile
#define OS_UNIX 1
#include "os_unix.c"
#undef OS_UNIX
#undef OsFile
#undef sqlite3OsOpenReadWrite
#undef sqlite3OsOpenExclusive
#undef sqlite3OsOpenReadOnly
#undef sqlite3OsOpenDirectory
#undef sqlite3OsClose
#undef sqlite3OsRead
#undef sqlite3OsWrite
#undef sqlite3OsSeek
#undef sqlite3OsSync
#undef sqlite3OsTruncate
#undef sqlite3OsFileSize
#undef sqlite3OsLock
#undef sqlite3OsUnlock
#undef sqlite3OsCheckReservedLock
#define BLOCKSIZE 512
#define BLOCK_OFFSET(x) ((x) * BLOCKSIZE)
/*
** The following variables control when a simulated crash occurs.
**
** If iCrashDelay is non-zero, then zCrashFile contains (full path) name of
** a file that SQLite will call sqlite3OsSync() on. Each time this happens
** iCrashDelay is decremented. If iCrashDelay is zero after being
** decremented, a "crash" occurs during the sync() operation.
**
** In other words, a crash occurs the iCrashDelay'th time zCrashFile is
** synced.
*/
static int iCrashDelay = 0;
char zCrashFile[256];
/*
** Set the value of the two crash parameters.
*/
void sqlite3SetCrashParams(int iDelay, char const *zFile){
sqlite3OsEnterMutex();
assert( strlen(zFile)<256 );
strcpy(zCrashFile, zFile);
iCrashDelay = iDelay;
sqlite3OsLeaveMutex();
}
/*
** File zPath is being sync()ed. Return non-zero if this should
** cause a crash.
*/
static int crashRequired(char const *zPath){
int r;
int n;
sqlite3OsEnterMutex();
n = strlen(zCrashFile);
if( zCrashFile[n-1]=='*' ){
n--;
}else if( strlen(zPath)>n ){
n = strlen(zPath);
}
r = 0;
if( iCrashDelay>0 && strncmp(zPath, zCrashFile, n)==0 ){
iCrashDelay--;
if( iCrashDelay<=0 ){
r = 1;
}
}
sqlite3OsLeaveMutex();
return r;
}
static OsTestFile *pAllFiles = 0;
/*
** Initialise the os_test.c specific fields of pFile.
*/
static void initFile(OsFile *id, char const *zName){
OsTestFile *pFile = (OsTestFile *)
sqliteMalloc(sizeof(OsTestFile) + strlen(zName)+1);
pFile->nMaxWrite = 0;
pFile->nBlk = 0;
pFile->apBlk = 0;
pFile->zName = (char *)(&pFile[1]);
strcpy(pFile->zName, zName);
*id = pFile;
pFile->pNext = pAllFiles;
pAllFiles = pFile;
}
/*
** Undo the work done by initFile. Delete the OsTestFile structure
** and unlink the structure from the pAllFiles list.
*/
static void closeFile(OsFile *id){
OsTestFile *pFile = *id;
if( pFile==pAllFiles ){
pAllFiles = pFile->pNext;
}else{
OsTestFile *p;
for(p=pAllFiles; p->pNext!=pFile; p=p->pNext ){
assert( p );
}
p->pNext = pFile->pNext;
}
sqliteFree(pFile);
*id = 0;
}
/*
** Return the current seek offset from the start of the file. This
** is unix-only code.
*/
static i64 osTell(OsTestFile *pFile){
return lseek(pFile->fd.h, 0, SEEK_CUR);
}
/*
** Load block 'blk' into the cache of pFile.
*/
static int cacheBlock(OsTestFile *pFile, int blk){
if( blk>=pFile->nBlk ){
int n = ((pFile->nBlk * 2) + 100 + blk);
/* if( pFile->nBlk==0 ){ printf("DIRTY %s\n", pFile->zName); } */
pFile->apBlk = (u8 **)sqliteRealloc(pFile->apBlk, n * sizeof(u8*));
if( !pFile->apBlk ) return SQLITE_NOMEM;
memset(&pFile->apBlk[pFile->nBlk], 0, (n - pFile->nBlk)*sizeof(u8*));
pFile->nBlk = n;
}
if( !pFile->apBlk[blk] ){
i64 filesize;
int rc;
u8 *p = sqliteMalloc(BLOCKSIZE);
if( !p ) return SQLITE_NOMEM;
pFile->apBlk[blk] = p;
rc = sqlite3RealFileSize(&pFile->fd, &filesize);
if( rc!=SQLITE_OK ) return rc;
if( BLOCK_OFFSET(blk)<filesize ){
int len = BLOCKSIZE;
rc = sqlite3RealSeek(&pFile->fd, blk*BLOCKSIZE);
if( BLOCK_OFFSET(blk+1)>filesize ){
len = filesize - BLOCK_OFFSET(blk);
}
if( rc!=SQLITE_OK ) return rc;
rc = sqlite3RealRead(&pFile->fd, p, len);
if( rc!=SQLITE_OK ) return rc;
}
}
return SQLITE_OK;
}
/* #define TRACE_WRITECACHE */
/*
** Write the cache of pFile to disk. If crash is non-zero, randomly
** skip blocks when writing. The cache is deleted before returning.
*/
static int writeCache2(OsTestFile *pFile, int crash){
int i;
int nMax = pFile->nMaxWrite;
i64 offset;
int rc = SQLITE_OK;
offset = osTell(pFile);
for(i=0; i<pFile->nBlk; i++){
u8 *p = pFile->apBlk[i];
if( p ){
int skip = 0;
int trash = 0;
if( crash ){
char random;
sqlite3Randomness(1, &random);
if( random & 0x01 ){
if( random & 0x02 ){
trash = 1;
#ifdef TRACE_WRITECACHE
printf("Trashing block %d of %s\n", i, pFile->zName);
#endif
}else{
skip = 1;
#ifdef TRACE_WRITECACHE
printf("Skiping block %d of %s\n", i, pFile->zName);
#endif
}
}else{
#ifdef TRACE_WRITECACHE
printf("Writing block %d of %s\n", i, pFile->zName);
#endif
}
}
if( rc==SQLITE_OK ){
rc = sqlite3RealSeek(&pFile->fd, BLOCK_OFFSET(i));
}
if( rc==SQLITE_OK && !skip ){
int len = BLOCKSIZE;
if( BLOCK_OFFSET(i+1)>nMax ){
len = nMax-BLOCK_OFFSET(i);
}
if( len>0 ){
if( trash ){
sqlite3Randomness(len, p);
}
rc = sqlite3RealWrite(&pFile->fd, p, len);
}
}
sqliteFree(p);
}
}
sqliteFree(pFile->apBlk);
pFile->nBlk = 0;
pFile->apBlk = 0;
pFile->nMaxWrite = 0;
if( rc==SQLITE_OK ){
rc = sqlite3RealSeek(&pFile->fd, offset);
}
return rc;
}
/*
** Write the cache to disk.
*/
static int writeCache(OsTestFile *pFile){
if( pFile->apBlk ){
int c = crashRequired(pFile->zName);
if( c ){
OsTestFile *p;
#ifdef TRACE_WRITECACHE
printf("\nCrash during sync of %s\n", pFile->zName);
#endif
for(p=pAllFiles; p; p=p->pNext){
writeCache2(p, 1);
}
exit(-1);
}else{
return writeCache2(pFile, 0);
}
}
return SQLITE_OK;
}
/*
** Close the file.
*/
int sqlite3OsClose(OsFile *id){
if( !(*id) ) return SQLITE_OK;
if( (*id)->fd.isOpen ){
/* printf("CLOSE %s (%d blocks)\n", (*id)->zName, (*id)->nBlk); */
writeCache(*id);
sqlite3RealClose(&(*id)->fd);
}
closeFile(id);
return SQLITE_OK;
}
int sqlite3OsRead(OsFile *id, void *pBuf, int amt){
i64 offset; /* The current offset from the start of the file */
i64 end; /* The byte just past the last byte read */
int blk; /* Block number the read starts on */
int i;
u8 *zCsr;
int rc = SQLITE_OK;
OsTestFile *pFile = *id;
offset = osTell(pFile);
end = offset+amt;
blk = (offset/BLOCKSIZE);
zCsr = (u8 *)pBuf;
for(i=blk; i*BLOCKSIZE<end; i++){
int off = 0;
int len = 0;
if( BLOCK_OFFSET(i) < offset ){
off = offset-BLOCK_OFFSET(i);
}
len = BLOCKSIZE - off;
if( BLOCK_OFFSET(i+1) > end ){
len = len - (BLOCK_OFFSET(i+1)-end);
}
if( i<pFile->nBlk && pFile->apBlk[i]){
u8 *pBlk = pFile->apBlk[i];
memcpy(zCsr, &pBlk[off], len);
}else{
rc = sqlite3RealSeek(&pFile->fd, BLOCK_OFFSET(i) + off);
if( rc!=SQLITE_OK ) return rc;
rc = sqlite3RealRead(&pFile->fd, zCsr, len);
if( rc!=SQLITE_OK ) return rc;
}
zCsr += len;
}
assert( zCsr==&((u8 *)pBuf)[amt] );
rc = sqlite3RealSeek(&pFile->fd, end);
return rc;
}
int sqlite3OsWrite(OsFile *id, const void *pBuf, int amt){
i64 offset; /* The current offset from the start of the file */
i64 end; /* The byte just past the last byte written */
int blk; /* Block number the write starts on */
int i;
const u8 *zCsr;
int rc = SQLITE_OK;
OsTestFile *pFile = *id;
offset = osTell(pFile);
end = offset+amt;
blk = (offset/BLOCKSIZE);
zCsr = (u8 *)pBuf;
for(i=blk; i*BLOCKSIZE<end; i++){
u8 *pBlk;
int off = 0;
int len = 0;
/* Make sure the block is in the cache */
rc = cacheBlock(pFile, i);
if( rc!=SQLITE_OK ) return rc;
/* Write into the cache */
pBlk = pFile->apBlk[i];
assert( pBlk );
if( BLOCK_OFFSET(i) < offset ){
off = offset-BLOCK_OFFSET(i);
}
len = BLOCKSIZE - off;
if( BLOCK_OFFSET(i+1) > end ){
len = len - (BLOCK_OFFSET(i+1)-end);
}
memcpy(&pBlk[off], zCsr, len);
zCsr += len;
}
if( pFile->nMaxWrite<end ){
pFile->nMaxWrite = end;
}
assert( zCsr==&((u8 *)pBuf)[amt] );
rc = sqlite3RealSeek(&pFile->fd, end);
return rc;
}
/*
** Sync the file. First flush the write-cache to disk, then call the
** real sync() function.
*/
int sqlite3OsSync(OsFile *id, int dataOnly){
int rc;
/* printf("SYNC %s (%d blocks)\n", (*id)->zName, (*id)->nBlk); */
rc = writeCache(*id);
if( rc!=SQLITE_OK ) return rc;
rc = sqlite3RealSync(&(*id)->fd, dataOnly);
return rc;
}
/*
** Truncate the file. Set the internal OsFile.nMaxWrite variable to the new
** file size to ensure that nothing in the write-cache past this point
** is written to disk.
*/
int sqlite3OsTruncate(OsFile *id, i64 nByte){
(*id)->nMaxWrite = nByte;
return sqlite3RealTruncate(&(*id)->fd, nByte);
}
/*
** Return the size of the file. If the cache contains a write that extended
** the file, then return this size instead of the on-disk size.
*/
int sqlite3OsFileSize(OsFile *id, i64 *pSize){
int rc = sqlite3RealFileSize(&(*id)->fd, pSize);
if( rc==SQLITE_OK && pSize && *pSize<(*id)->nMaxWrite ){
*pSize = (*id)->nMaxWrite;
}
return rc;
}
/*
** The three functions used to open files. All that is required is to
** initialise the os_test.c specific fields and then call the corresponding
** os_unix.c function to really open the file.
*/
int sqlite3OsOpenReadWrite(const char *zFilename, OsFile *id, int *pReadonly){
initFile(id, zFilename);
return sqlite3RealOpenReadWrite(zFilename, &(*id)->fd, pReadonly);
}
int sqlite3OsOpenExclusive(const char *zFilename, OsFile *id, int delFlag){
initFile(id, zFilename);
return sqlite3RealOpenExclusive(zFilename, &(*id)->fd, delFlag);
}
int sqlite3OsOpenReadOnly(const char *zFilename, OsFile *id){
initFile(id, zFilename);
return sqlite3RealOpenReadOnly(zFilename, &(*id)->fd);
}
/*
** These six function calls are passed straight through to the os_unix.c
** backend.
*/
int sqlite3OsSeek(OsFile *id, i64 offset){
return sqlite3RealSeek(&(*id)->fd, offset);
}
int sqlite3OsCheckReservedLock(OsFile *id){
return sqlite3RealCheckReservedLock(&(*id)->fd);
}
int sqlite3OsLock(OsFile *id, int locktype){
return sqlite3RealLock(&(*id)->fd, locktype);
}
int sqlite3OsUnlock(OsFile *id, int locktype){
return sqlite3RealUnlock(&(*id)->fd, locktype);
}
int sqlite3OsOpenDirectory(const char *zDirname, OsFile *id){
return sqlite3RealOpenDirectory(zDirname, &(*id)->fd);
}
#endif /* OS_TEST */