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Changes to the multiplex VFS to optionally (compiler define) allow

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the "chunk extension" to overwrite the right-most chars of the filename 
instead of simply being appended.

FossilOrigin-Name: 07da0a0beffda324d28fd2768c542ff69d4dbff2
This commit is contained in:
shaneh
2010-11-08 19:16:16 +00:00
parent 0596beec9f
commit 050d09abdc
5 changed files with 131 additions and 51 deletions
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110
src/test_multiplex.c
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@@ -26,9 +26,27 @@
/************************ Shim Definitions ******************************/
/* This is the limit on the chunk size. It may be changed by calling
** the sqlite3_multiplex_set() interface.
*/
#define SQLITE_MULTIPLEX_CHUNK_SIZE 0x40000000
/* Default limit on number of chunks. Care should be taken
** so that values for chunks numbers fit in the SQLITE_MULTIPLEX_EXT_FMT
** format specifier. It may be changed by calling
** the sqlite3_multiplex_set() interface.
*/
#define SQLITE_MULTIPLEX_MAX_CHUNKS 32
#define SQLITE_MULTIPLEX_EXT_FMT "-%04d"
/* If SQLITE_MULTIPLEX_EXT_OVWR is defined, the
** last SQLITE_MULTIPLEX_EXT_SZ characters of the
** filename will be overwritten, otherwise, the
** multiplex extension is simply appended to the filename.
** Ex. (undefined) test.db -> test.db01
** (defined) test.db -> test.01
** Chunk 0 does not have a modified extension.
*/
#define SQLITE_MULTIPLEX_EXT_FMT "%02d"
#define SQLITE_MULTIPLEX_EXT_SZ 2
/************************ Object Definitions ******************************/
@@ -45,11 +63,11 @@ typedef struct multiplexConn multiplexConn;
** group.
*/
struct multiplexGroup {
sqlite3_file *pReal[SQLITE_MULTIPLEX_MAX_CHUNKS]; /* Handles to each chunk */
char bOpen[SQLITE_MULTIPLEX_MAX_CHUNKS]; /* 0 if chunk not opened */
char *zName; /* Base filename of this group */
int nName; /* Length of base filename */
int flags; /* Flags used for original opening */
sqlite3_file **pReal; /* Handles to each chunk */
char *bOpen; /* 0 if chunk not opened */
char *zName; /* Base filename of this group */
int nName; /* Length of base filename */
int flags; /* Flags used for original opening */
multiplexGroup *pNext, *pPrev; /* Doubly linked list of all group objects */
};
@@ -137,9 +155,15 @@ static sqlite3_file *multiplexSubOpen(multiplexConn *pConn, int iChunk, int *rc,
if( iChunk<gMultiplex.nMaxChunks ){
sqlite3_file *pSubOpen = pGroup->pReal[iChunk]; /* Real file descriptor */
if( !pGroup->bOpen[iChunk] ){
pGroup->zName[pGroup->nName] = '\0';
if( iChunk ) sqlite3_snprintf(pGroup->nName+6, pGroup->zName+pGroup->nName, SQLITE_MULTIPLEX_EXT_FMT, iChunk);
*rc = pOrigVfs->xOpen(pOrigVfs, pGroup->zName, pSubOpen, pGroup->flags, pOutFlags);
memcpy(gMultiplex.zName, pGroup->zName, pGroup->nName+1);
if( iChunk ){
#ifdef SQLITE_MULTIPLEX_EXT_OVWR
sqlite3_snprintf(SQLITE_MULTIPLEX_EXT_SZ+1, gMultiplex.zName+pGroup->nName-SQLITE_MULTIPLEX_EXT_SZ, SQLITE_MULTIPLEX_EXT_FMT, iChunk);
#else
sqlite3_snprintf(SQLITE_MULTIPLEX_EXT_SZ+1, gMultiplex.zName+pGroup->nName, SQLITE_MULTIPLEX_EXT_FMT, iChunk);
#endif
}
*rc = pOrigVfs->xOpen(pOrigVfs, gMultiplex.zName, pSubOpen, pGroup->flags, pOutFlags);
if( *rc==SQLITE_OK ){
pGroup->bOpen[iChunk] = -1;
return pSubOpen;
@@ -176,6 +200,7 @@ static int multiplexOpen(
sqlite3_vfs *pOrigVfs = gMultiplex.pOrigVfs; /* Real VFS */
int nName = sqlite3Strlen30(zName);
int i;
int sz;
UNUSED_PARAMETER(pVfs);
@@ -184,20 +209,37 @@ static int multiplexOpen(
*/
multiplexEnter();
pMultiplexOpen = (multiplexConn*)pConn;
/* allocate space for group, file handles,
** and file name (+ extra for "-0000\0")
*/
pGroup = sqlite3_malloc( sizeof(multiplexGroup) + (pOrigVfs->szOsFile*gMultiplex.nMaxChunks) + nName + 6 );
/* allocate space for group */
sz = sizeof(multiplexGroup) /* multiplexGroup */
+ (sizeof(sqlite3_file *)*gMultiplex.nMaxChunks) /* pReal[] */
+ (pOrigVfs->szOsFile*gMultiplex.nMaxChunks) /* *pReal */
+ gMultiplex.nMaxChunks /* bOpen[] */
+ nName + 1; /* zName */
#ifndef SQLITE_MULTIPLEX_EXT_OVWR
sz += SQLITE_MULTIPLEX_EXT_SZ;
assert(nName+SQLITE_MULTIPLEX_EXT_SZ < pOrigVfs->mxPathname);
#else
assert(nName >= SQLITE_MULTIPLEX_EXT_SZ);
assert(nName < pOrigVfs->mxPathname);
#endif
pGroup = sqlite3_malloc( sz );
if( pGroup==0 ){
rc=SQLITE_NOMEM;
}else{
/* assign pointers to extra space allocated */
char *p = (char *)&pGroup[1];
pMultiplexOpen->pGroup = pGroup;
memset(pGroup, 0, sizeof(multiplexGroup) + (pOrigVfs->szOsFile*gMultiplex.nMaxChunks) + nName + 6);
/* assign pointers to extra space for file handles */
memset(pGroup, 0, sz);
pGroup->pReal = (sqlite3_file **)p;
p += (sizeof(sqlite3_file *)*gMultiplex.nMaxChunks);
for(i=0; i<gMultiplex.nMaxChunks; i++){
pGroup->pReal[i] = (sqlite3_file *)((char *)&pGroup[1] + (pOrigVfs->szOsFile*i));
pGroup->pReal[i] = (sqlite3_file *)p;
p += pOrigVfs->szOsFile;
}
pGroup->zName = (char *)&pGroup[1] + (pOrigVfs->szOsFile*gMultiplex.nMaxChunks);
pGroup->bOpen = p;
p += gMultiplex.nMaxChunks;
pGroup->zName = p;
/* save off base filename, name length, and original open flags */
memcpy(pGroup->zName, zName, nName+1);
pGroup->nName = nName;
pGroup->flags = flags;
@@ -223,7 +265,7 @@ static int multiplexOpen(
/*
** This is the xDelete method used for the "multiplex" VFS.
** It attempts to delete the filename specified, as well
** as addiitional files with the "-####" extension.
** as additional files with the SQLITE_MULTIPLEX_EXT_FMT extension.
*/
static int multiplexDelete(
sqlite3_vfs *pVfs, /* The multiplex VFS */
@@ -242,7 +284,13 @@ static int multiplexDelete(
for(i=0; i<gMultiplex.nMaxChunks; i++){
int rc2;
int exists = 0;
if( i ) sqlite3_snprintf(nName+6, gMultiplex.zName+nName, SQLITE_MULTIPLEX_EXT_FMT, i);
if( i ){
#ifdef SQLITE_MULTIPLEX_EXT_OVWR
sqlite3_snprintf(SQLITE_MULTIPLEX_EXT_SZ+1, gMultiplex.zName+nName-SQLITE_MULTIPLEX_EXT_SZ, SQLITE_MULTIPLEX_EXT_FMT, i);
#else
sqlite3_snprintf(SQLITE_MULTIPLEX_EXT_SZ+1, gMultiplex.zName+nName, SQLITE_MULTIPLEX_EXT_FMT, i);
#endif
}
rc2 = pOrigVfs->xAccess(pOrigVfs, gMultiplex.zName, SQLITE_ACCESS_EXISTS, &exists);
if( rc2==SQLITE_OK && exists){
/* if it exists, delete it */
@@ -372,6 +420,7 @@ static int multiplexTruncate(sqlite3_file *pConn, sqlite3_int64 size){
sqlite3_file *pSubOpen;
sqlite3_vfs *pOrigVfs = gMultiplex.pOrigVfs; /* Real VFS */
multiplexEnter();
memcpy(gMultiplex.zName, pGroup->zName, pGroup->nName+1);
/* delete the chunks above the truncate limit */
for(i=(int)(size/gMultiplex.nChunkSize)+1; i<gMultiplex.nMaxChunks; i++){
/* close any open chunks before deleting them */
@@ -381,8 +430,12 @@ static int multiplexTruncate(sqlite3_file *pConn, sqlite3_int64 size){
if( rc2!=SQLITE_OK ) rc = SQLITE_IOERR_TRUNCATE;
pGroup->bOpen[i] = 0;
}
sqlite3_snprintf(pGroup->nName+6, pGroup->zName+pGroup->nName, SQLITE_MULTIPLEX_EXT_FMT, i);
rc2 = pOrigVfs->xDelete(pOrigVfs, pGroup->zName, 0);
#ifdef SQLITE_MULTIPLEX_EXT_OVWR
sqlite3_snprintf(SQLITE_MULTIPLEX_EXT_SZ+1, gMultiplex.zName+pGroup->nName-SQLITE_MULTIPLEX_EXT_SZ, SQLITE_MULTIPLEX_EXT_FMT, i);
#else
sqlite3_snprintf(SQLITE_MULTIPLEX_EXT_SZ+1, gMultiplex.zName+pGroup->nName, SQLITE_MULTIPLEX_EXT_FMT, i);
#endif
rc2 = pOrigVfs->xDelete(pOrigVfs, gMultiplex.zName, 0);
if( rc2!=SQLITE_OK ) rc = SQLITE_IOERR_TRUNCATE;
}
pSubOpen = multiplexSubOpen(p, (int)(size/gMultiplex.nChunkSize), &rc2, NULL);
@@ -435,9 +488,15 @@ static int multiplexFileSize(sqlite3_file *pConn, sqlite3_int64 *pSize){
}else{
sqlite3_vfs *pOrigVfs = gMultiplex.pOrigVfs; /* Real VFS */
int exists = 0;
pGroup->zName[pGroup->nName] = '\0';
if( i ) sqlite3_snprintf(pGroup->nName+6, pGroup->zName+pGroup->nName, SQLITE_MULTIPLEX_EXT_FMT, i);
rc2 = pOrigVfs->xAccess(pOrigVfs, pGroup->zName, SQLITE_ACCESS_EXISTS, &exists);
memcpy(gMultiplex.zName, pGroup->zName, pGroup->nName+1);
if( i ){
#ifdef SQLITE_MULTIPLEX_EXT_OVWR
sqlite3_snprintf(SQLITE_MULTIPLEX_EXT_SZ+1, gMultiplex.zName+pGroup->nName-SQLITE_MULTIPLEX_EXT_SZ, SQLITE_MULTIPLEX_EXT_FMT, i);
#else
sqlite3_snprintf(SQLITE_MULTIPLEX_EXT_SZ+1, gMultiplex.zName+pGroup->nName, SQLITE_MULTIPLEX_EXT_FMT, i);
#endif
}
rc2 = pOrigVfs->xAccess(pOrigVfs, gMultiplex.zName, SQLITE_ACCESS_EXISTS, &exists);
if( rc2==SQLITE_OK && exists){
/* if it exists, open it */
pSubOpen = multiplexSubOpen(p, i, &rc, NULL);
@@ -453,6 +512,7 @@ static int multiplexFileSize(sqlite3_file *pConn, sqlite3_int64 *pSize){
rc = rc2;
}else{
*pSize += sz;
assert(sz<=gMultiplex.nChunkSize);
}
}else{
break;
@@ -687,7 +747,7 @@ int sqlite3_multiplex_set(
if( gMultiplex.pGroups ) return SQLITE_MISUSE;
if( nChunkSize<32 ) return SQLITE_MISUSE;
if( nMaxChunks<1 ) return SQLITE_MISUSE;
if( nMaxChunks>SQLITE_MULTIPLEX_MAX_CHUNKS ) return SQLITE_MISUSE;
if( nMaxChunks>99 ) return SQLITE_MISUSE;
multiplexEnter();
gMultiplex.nChunkSize = nChunkSize;
gMultiplex.nMaxChunks = nMaxChunks;