diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/test_multiplex.c | 111 |
1 files changed, 93 insertions, 18 deletions
diff --git a/src/test_multiplex.c b/src/test_multiplex.c index d8a7db86e..861e68e87 100644 --- a/src/test_multiplex.c +++ b/src/test_multiplex.c @@ -185,13 +185,72 @@ static void multiplexLeave(void){ sqlite3_mutex_leave(gMultiplex.pMutex); } ** than the actual length of the string. For very long strings (greater ** than 1GiB) the value returned might be less than the true string length. */ -int multiplexStrlen30(const char *z){ +static int multiplexStrlen30(const char *z){ const char *z2 = z; if( z==0 ) return 0; while( *z2 ){ z2++; } return 0x3fffffff & (int)(z2 - z); } +/* +** Create a temporary file name in zBuf. zBuf must be big enough to +** hold at pOrigVfs->mxPathname characters. This function departs +** from the traditional temporary name generation in the os_win +** and os_unix VFS in several ways, but is necessary so that +** the file name is known for temporary files (like those used +** during vacuum.) +** +** N.B. This routine assumes your underlying VFS is ok with using +** "/" as a directory seperator. This is the default for UNIXs +** and is allowed (even mixed) for most versions of Windows. +*/ +static int multiplexGetTempname(sqlite3_vfs *pOrigVfs, int nBuf, char *zBuf){ + static char zChars[] = + "abcdefghijklmnopqrstuvwxyz" + "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "0123456789"; + int i,j; + int attempts = 0; + int exists = 0; + int rc = SQLITE_ERROR; + + /* Check that the output buffer is large enough for + ** pVfs->mxPathname characters. + */ + if( pOrigVfs->mxPathname <= nBuf ){ + + /* sqlite3_temp_directory should always be less than + ** pVfs->mxPathname characters. + */ + sqlite3_snprintf(pOrigVfs->mxPathname, + zBuf, + "%s/", + sqlite3_temp_directory ? sqlite3_temp_directory : "."); + + /* Check that the output buffer is large enough for the temporary file + ** name. + */ + j = multiplexStrlen30(zBuf); + if( (j + 8 + 1 + 3 + 1) <= nBuf ){ + /* Make 3 attempts to generate a unique name. */ + do { + attempts++; + sqlite3_randomness(8, &zBuf[j]); + for(i=0; i<8; i++){ + zBuf[j+i] = (char)zChars[ ((unsigned char)zBuf[j+i])%(sizeof(zChars)-1) ]; + } + memcpy(&zBuf[j+i], ".tmp", 5); + rc = pOrigVfs->xAccess(pOrigVfs, zBuf, SQLITE_ACCESS_EXISTS, &exists); + } while ( (rc==SQLITE_OK) && exists && (attempts<3) ); + if( rc==SQLITE_OK && exists ){ + rc = SQLITE_ERROR; + } + } + } + + return rc; +} + /* Translate an sqlite3_file* that is really a multiplexGroup* into ** the sqlite3_file* for the underlying original VFS. */ @@ -295,12 +354,12 @@ static int multiplexOpen( int flags, /* Flags to control the opening */ int *pOutFlags /* Flags showing results of opening */ ){ - int rc; /* Result code */ + int rc = SQLITE_OK; /* Result code */ multiplexConn *pMultiplexOpen; /* The new multiplex file descriptor */ multiplexGroup *pGroup; /* Corresponding multiplexGroup object */ sqlite3_file *pSubOpen; /* Real file descriptor */ sqlite3_vfs *pOrigVfs = gMultiplex.pOrigVfs; /* Real VFS */ - int nName = multiplexStrlen30(zName); + int nName; int i; int sz; @@ -311,23 +370,39 @@ static int multiplexOpen( */ multiplexEnter(); pMultiplexOpen = (multiplexConn*)pConn; - /* allocate space for group */ - sz = sizeof(multiplexGroup) /* multiplexGroup */ - + (sizeof(sqlite3_file *)*SQLITE_MULTIPLEX_MAX_CHUNKS) /* pReal[] */ - + (pOrigVfs->szOsFile*SQLITE_MULTIPLEX_MAX_CHUNKS) /* *pReal */ - + SQLITE_MULTIPLEX_MAX_CHUNKS /* bOpen[] */ - + nName + 1; /* zName */ + + /* If the second argument to this function is NULL, generate a + ** temporary file name to use. This will be handled by the + ** original xOpen method. We just need to allocate space for + ** it. + */ + if( !zName ){ + rc = multiplexGetTempname(pOrigVfs, pOrigVfs->mxPathname, gMultiplex.zName); + zName = gMultiplex.zName; + } + + if( rc==SQLITE_OK ){ + /* allocate space for group */ + nName = multiplexStrlen30(zName); + sz = sizeof(multiplexGroup) /* multiplexGroup */ + + (sizeof(sqlite3_file *)*SQLITE_MULTIPLEX_MAX_CHUNKS) /* pReal[] */ + + (pOrigVfs->szOsFile*SQLITE_MULTIPLEX_MAX_CHUNKS) /* *pReal */ + + SQLITE_MULTIPLEX_MAX_CHUNKS /* bOpen[] */ + + nName + 1; /* zName */ #ifndef SQLITE_MULTIPLEX_EXT_OVWR - sz += SQLITE_MULTIPLEX_EXT_SZ; - assert(nName+SQLITE_MULTIPLEX_EXT_SZ < pOrigVfs->mxPathname); + sz += SQLITE_MULTIPLEX_EXT_SZ; + assert(nName+SQLITE_MULTIPLEX_EXT_SZ < pOrigVfs->mxPathname); #else - assert(nName >= SQLITE_MULTIPLEX_EXT_SZ); - assert(nName < pOrigVfs->mxPathname); + assert(nName >= SQLITE_MULTIPLEX_EXT_SZ); + assert(nName < pOrigVfs->mxPathname); #endif - pGroup = sqlite3_malloc( sz ); - if( pGroup==0 ){ - rc=SQLITE_NOMEM; - }else{ + pGroup = sqlite3_malloc( sz ); + if( pGroup==0 ){ + rc=SQLITE_NOMEM; + } + } + + if( rc==SQLITE_OK ){ /* assign pointers to extra space allocated */ char *p = (char *)&pGroup[1]; pMultiplexOpen->pGroup = pGroup; @@ -411,7 +486,7 @@ static int multiplexDelete( } rc2 = pOrigVfs->xAccess(pOrigVfs, gMultiplex.zName, SQLITE_ACCESS_EXISTS, &exists); - if( rc2==SQLITE_OK && exists){ + if( rc2==SQLITE_OK && exists ){ /* if it exists, delete it */ rc2 = pOrigVfs->xDelete(pOrigVfs, gMultiplex.zName, syncDir); if( rc2!=SQLITE_OK ) rc = rc2; |