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Separate sqlite3_io_methods objects for database files and journals.

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FossilOrigin-Name: 74fbf6c2a97729e481d5562344e960d0c237aeb1f07240262d32a24fb1f4b5a3
This commit is contained in:
drh
2022-09-09 14:22:41 +00:00
parent 126976c9f8
commit f7377d5763
3 changed files with 188 additions and 164 deletions
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338
ext/misc/vfskv.c
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@ -28,11 +28,15 @@ SQLITE_EXTENSION_INIT1
/*****************************************************************************
** Debugging logic
*/
/* KVVFS_TRACE() is used for tracing calls to kvstorage routines. */
#if 0
#define KVVFS_TRACE(X) printf X;
#else
#define KVVFS_TRACE(X)
#endif
/* KVVFS_LOG() is used for tracing calls to the VFS interface */
#if 0
#define KVVFS_LOG(X) printf X;
#else
@ -88,11 +92,16 @@ struct KVVfsFile {
** Methods for KVVfsFile
*/
static int kvvfsClose(sqlite3_file*);
static int kvvfsRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
static int kvvfsWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64 iOfst);
static int kvvfsTruncate(sqlite3_file*, sqlite3_int64 size);
static int kvvfsSync(sqlite3_file*, int flags);
static int kvvfsFileSize(sqlite3_file*, sqlite3_int64 *pSize);
static int kvvfsReadDb(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
static int kvvfsReadJrnl(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
static int kvvfsWriteDb(sqlite3_file*,const void*,int iAmt, sqlite3_int64);
static int kvvfsWriteJrnl(sqlite3_file*,const void*,int iAmt, sqlite3_int64);
static int kvvfsTruncateDb(sqlite3_file*, sqlite3_int64 size);
static int kvvfsTruncateJrnl(sqlite3_file*, sqlite3_int64 size);
static int kvvfsSyncDb(sqlite3_file*, int flags);
static int kvvfsSyncJrnl(sqlite3_file*, int flags);
static int kvvfsFileSizeDb(sqlite3_file*, sqlite3_int64 *pSize);
static int kvvfsFileSizeJrnl(sqlite3_file*, sqlite3_int64 *pSize);
static int kvvfsLock(sqlite3_file*, int);
static int kvvfsUnlock(sqlite3_file*, int);
static int kvvfsCheckReservedLock(sqlite3_file*, int *pResOut);
@ -139,14 +148,40 @@ static KVVfsVfs kvvfs_vfs = {
0
};
static sqlite3_io_methods kvvfs_io_methods = {
/* Methods for sqlite3_file objects referencing a database file
*/
static sqlite3_io_methods kvvfs_db_io_methods = {
1, /* iVersion */
kvvfsClose, /* xClose */
kvvfsRead, /* xRead */
kvvfsWrite, /* xWrite */
kvvfsTruncate, /* xTruncate */
kvvfsSync, /* xSync */
kvvfsFileSize, /* xFileSize */
kvvfsReadDb, /* xRead */
kvvfsWriteDb, /* xWrite */
kvvfsTruncateDb, /* xTruncate */
kvvfsSyncDb, /* xSync */
kvvfsFileSizeDb, /* xFileSize */
kvvfsLock, /* xLock */
kvvfsUnlock, /* xUnlock */
kvvfsCheckReservedLock, /* xCheckReservedLock */
kvvfsFileControl, /* xFileControl */
kvvfsSectorSize, /* xSectorSize */
kvvfsDeviceCharacteristics, /* xDeviceCharacteristics */
0, /* xShmMap */
0, /* xShmLock */
0, /* xShmBarrier */
0, /* xShmUnmap */
0, /* xFetch */
0 /* xUnfetch */
};
/* Methods for sqlite3_file objects referencing a rollback journal
*/
static sqlite3_io_methods kvvfs_jrnl_io_methods = {
1, /* iVersion */
kvvfsClose, /* xClose */
kvvfsReadJrnl, /* xRead */
kvvfsWriteJrnl, /* xWrite */
kvvfsTruncateJrnl, /* xTruncate */
kvvfsSyncJrnl, /* xSync */
kvvfsFileSizeJrnl, /* xFileSize */
kvvfsLock, /* xLock */
kvvfsUnlock, /* xUnlock */
kvvfsCheckReservedLock, /* xCheckReservedLock */
@ -200,8 +235,9 @@ static int kvstorageWrite(
kvstorageMakeKey(pStore, zKey);
fd = fopen(pStore->zKey, "wb");
if( fd ){
KVVFS_TRACE(("KVVFS-WRITE %-14s (%d) %.30s\n", pStore->zKey,
(int)strlen(zData), zData));
KVVFS_TRACE(("KVVFS-WRITE %-10s (%d) %.50s%s\n", pStore->zKey,
(int)strlen(zData), zData,
strlen(zData)>50 ? "..." : ""));
fputs(zData, fd);
fclose(fd);
return 0;
@ -215,7 +251,7 @@ static int kvstorageWrite(
static int kvstorageDelete(KVStorage *pStore, const char *zKey){
kvstorageMakeKey(pStore, zKey);
unlink(pStore->zKey);
KVVFS_TRACE(("KVVFS-DELETE %-14s\n", pStore->zKey));
KVVFS_TRACE(("KVVFS-DELETE %-10s\n", pStore->zKey));
return 0;
}
@ -244,14 +280,14 @@ static int kvstorageRead(
|| stat(pStore->zKey, &buf)!=0
|| !S_ISREG(buf.st_mode)
){
KVVFS_TRACE(("KVVFS-READ %-14s (-1)\n", pStore->zKey));
KVVFS_TRACE(("KVVFS-READ %-10s (-1)\n", pStore->zKey));
return -1;
}
if( nBuf<0 ){
return (int)buf.st_size;
}else if( nBuf==1 ){
zBuf[0] = 0;
KVVFS_TRACE(("KVVFS-READ %-14s (%d)\n", pStore->zKey,
KVVFS_TRACE(("KVVFS-READ %-10s (%d)\n", pStore->zKey,
(int)buf.st_size));
return (int)buf.st_size;
}
@ -260,49 +296,20 @@ static int kvstorageRead(
}
fd = fopen(pStore->zKey, "rb");
if( fd==0 ){
KVVFS_TRACE(("KVVFS-READ %-14s (-1)\n", pStore->zKey));
KVVFS_TRACE(("KVVFS-READ %-10s (-1)\n", pStore->zKey));
return -1;
}else{
sqlite3_int64 n = fread(zBuf, 1, nBuf-1, fd);
fclose(fd);
zBuf[n] = 0;
KVVFS_TRACE(("KVVFS-READ %-14s (%lld) %.30s\n", pStore->zKey,
n, zBuf));
KVVFS_TRACE(("KVVFS-READ %-10s (%lld) %.50s%s\n", pStore->zKey,
n, zBuf, n>50 ? "..." : ""));
return (int)n;
}
}
/****** Utility subroutines ************************************************/
/****** The main VFS code **************************************************/
/*
** Close an kvvfs-file.
*/
static int kvvfsClose(sqlite3_file *pProtoFile){
KVVfsFile *pFile = (KVVfsFile *)pProtoFile;
KVVfsVfs *pVfs = pFile->pVfs;
KVVFS_LOG(("xClose %s\n", pFile->isJournal ? "journal" : "db"));
if( pVfs->pFiles==pFile ){
pVfs->pFiles = pFile->pNext;
if( pVfs->pFiles==0 ){
kvstorageClose(pVfs->pStore);
pVfs->pStore = 0;
}
}else{
KVVfsFile *pX = pVfs->pFiles;
while( 1 ){
assert( pX );
if( pX->pNext==pFile ){
pX->pNext = pFile->pNext;
break;
}
pX = pX->pNext;
}
}
sqlite3_free(pFile->aJrnl);
return SQLITE_OK;
}
/*
** Encode binary into the text encoded used to persist on disk.
@ -311,6 +318,20 @@ static int kvvfsClose(sqlite3_file *pProtoFile){
**
** Return the actual length of the encoded text, not counting the
** zero terminator at the end.
**
** Encoding format
** ---------------
**
** * Non-zero bytes are encoded as upper-case hexadecimal
**
** * A sequence of one or more zero-bytes that are not at the
** beginning of the buffer are encoded as a little-endian
** base-26 number using a..z. "a" means 0. "b" means 1,
** "z" means 25. "ab" means 26. "ac" means 52. And so forth.
**
** * Because there is no overlap between the encoding characters
** of hexadecimal and base-26 numbers, it is always clear where
** one stops and the next begins.
*/
static int kvvfsEncode(const char *aData, int nData, char *aOut){
int i, j;
@ -384,9 +405,11 @@ static int kvvfsDecode(const char *aIn, char *aOut, int nOut){
** and store the decoding there. Or leave pFile->aJrnl set to NULL
** if an error is encountered.
**
** The first few characters of the text encoding will be a
** The first few characters of the text encoding will be a little-endian
** base-26 number (digits a..z) that is the total number of bytes
** in the decoding. Use this number to size the initial allocation.
** in the decoded journal file image. This base-26 number is followed
** by a single space, then the encoding of the journal. The space
** separator is required to act as a terminator for the base-26 number.
*/
static void kvvfsDecodeJournal(
KVVfsFile *pFile, /* Store decoding in pFile->aJrnl */
@ -397,10 +420,9 @@ static void kvvfsDecodeJournal(
int c, i, mult;
i = 0;
mult = 1;
while( (c = zTxt[i])>='a' && c<='z' ){
while( (c = zTxt[i++])>='a' && c<='z' ){
n += (zTxt[i] - 'a')*mult;
mult *= 26;
i++;
}
sqlite3_free(pFile->aJrnl);
pFile->aJrnl = sqlite3_malloc64( n );
@ -417,26 +439,73 @@ static void kvvfsDecodeJournal(
}
}
/*
** Read or write the "sz" element, containing the database file size.
*/
static sqlite3_int64 kvvfsReadFileSize(KVVfsFile *pFile){
char zData[50];
zData[0] = 0;
kvstorageRead(pFile->pVfs->pStore, "sz", zData, sizeof(zData)-1);
return strtoll(zData, 0, 0);
}
static void kvvfsWriteFileSize(KVVfsFile *pFile, sqlite3_int64 sz){
char zData[50];
sqlite3_snprintf(sizeof(zData), zData, "%lld", sz);
kvstorageWrite(pFile->pVfs->pStore, "sz", zData);
}
/****** VFS methods ********************************************************/
/*
** Close an kvvfs-file.
*/
static int kvvfsClose(sqlite3_file *pProtoFile){
KVVfsFile *pFile = (KVVfsFile *)pProtoFile;
KVVfsVfs *pVfs = pFile->pVfs;
KVVFS_LOG(("xClose %s\n", pFile->isJournal ? "journal" : "db"));
if( pVfs->pFiles==pFile ){
pVfs->pFiles = pFile->pNext;
if( pVfs->pFiles==0 ){
kvstorageClose(pVfs->pStore);
pVfs->pStore = 0;
}
}else{
KVVfsFile *pX = pVfs->pFiles;
while( 1 ){
assert( pX );
if( pX->pNext==pFile ){
pX->pNext = pFile->pNext;
break;
}
pX = pX->pNext;
}
}
sqlite3_free(pFile->aJrnl);
return SQLITE_OK;
}
/*
** Read from the -journal file.
*/
static int kvvfsReadFromJournal(
KVVfsFile *pFile,
static int kvvfsReadJrnl(
sqlite3_file *pProtoFile,
void *zBuf,
int iAmt,
sqlite_int64 iOfst
){
KVVfsFile *pFile = (KVVfsFile*)pProtoFile;
assert( pFile->isJournal );
KVVFS_LOG(("xRead('journal',%d,%lld)\n", iAmt, iOfst));
if( pFile->aJrnl==0 ){
int szTxt = kvstorageRead(pFile->pVfs->pStore, "journal", 0, 0);
int szTxt = kvstorageRead(pFile->pVfs->pStore, "jrnl", 0, 0);
char *aTxt;
if( szTxt<=4 ){
return SQLITE_IOERR;
}
aTxt = sqlite3_malloc64( szTxt+1 );
if( aTxt==0 ) return SQLITE_NOMEM;
kvstorageRead(pFile->pVfs->pStore, "journal", aTxt, szTxt+1);
kvstorageRead(pFile->pVfs->pStore, "jrnl", aTxt, szTxt+1);
kvvfsDecodeJournal(pFile, aTxt, szTxt);
sqlite3_free(aTxt);
if( pFile->aJrnl==0 ) return SQLITE_IOERR;
@ -451,12 +520,13 @@ static int kvvfsReadFromJournal(
/*
** Read from the database file.
*/
static int kvvfsReadFromDb(
KVVfsFile *pFile,
static int kvvfsReadDb(
sqlite3_file *pProtoFile,
void *zBuf,
int iAmt,
sqlite_int64 iOfst
){
KVVfsFile *pFile = (KVVfsFile*)pProtoFile;
unsigned int pgno;
int got, n;
char zKey[30];
@ -476,7 +546,7 @@ static int kvvfsReadFromDb(
}else{
pgno = 1;
}
sqlite3_snprintf(sizeof(zKey), zKey, "pg-%u", pgno);
sqlite3_snprintf(sizeof(zKey), zKey, "%u", pgno);
got = kvstorageRead(pFile->pVfs->pStore, zKey, aData, sizeof(aData)-1);
if( got<0 ){
n = 0;
@ -502,50 +572,16 @@ static int kvvfsReadFromDb(
}
/*
** Read data from an kvvfs-file.
*/
static int kvvfsRead(
sqlite3_file *pProtoFile,
void *zBuf,
int iAmt,
sqlite_int64 iOfst
){
int rc;
KVVfsFile *pFile = (KVVfsFile *)pProtoFile;
if( pFile->isJournal ){
rc = kvvfsReadFromJournal(pFile,zBuf,iAmt,iOfst);
}else{
rc = kvvfsReadFromDb(pFile,zBuf,iAmt,iOfst);
}
KVVFS_LOG(("xRead result: 0x%x\n", rc));
return rc;
}
/*
** Read or write the "sz" element, containing the database file size.
*/
static sqlite3_int64 kvvfsReadFileSize(KVVfsFile *pFile){
char zData[50];
zData[0] = 0;
kvstorageRead(pFile->pVfs->pStore, "sz", zData, sizeof(zData)-1);
return strtoll(zData, 0, 0);
}
static void kvvfsWriteFileSize(KVVfsFile *pFile, sqlite3_int64 sz){
char zData[50];
sqlite3_snprintf(sizeof(zData), zData, "%lld", sz);
kvstorageWrite(pFile->pVfs->pStore, "sz", zData);
}
/*
** Write into the -journal file.
*/
static int kvvfsWriteToJournal(
KVVfsFile *pFile,
static int kvvfsWriteJrnl(
sqlite3_file *pProtoFile,
const void *zBuf,
int iAmt,
sqlite_int64 iOfst
){
KVVfsFile *pFile = (KVVfsFile*)pProtoFile;
sqlite3_int64 iEnd = iOfst+iAmt;
KVVFS_LOG(("xWrite('journal',%d,%lld)\n", iAmt, iOfst));
if( iEnd>=0x10000000 ) return SQLITE_FULL;
@ -567,12 +603,13 @@ static int kvvfsWriteToJournal(
/*
** Write into the database file.
*/
static int kvvfsWriteToDb(
KVVfsFile *pFile,
static int kvvfsWriteDb(
sqlite3_file *pProtoFile,
const void *zBuf,
int iAmt,
sqlite_int64 iOfst
){
KVVfsFile *pFile = (KVVfsFile*)pProtoFile;
unsigned int pgno;
char zKey[30];
char aData[131073];
@ -580,7 +617,7 @@ static int kvvfsWriteToDb(
assert( iAmt>=512 && iAmt<=65536 );
assert( (iAmt & (iAmt-1))==0 );
pgno = 1 + iOfst/iAmt;
sqlite3_snprintf(sizeof(zKey), zKey, "pg-%u", pgno);
sqlite3_snprintf(sizeof(zKey), zKey, "%u", pgno);
kvvfsEncode(zBuf, iAmt, aData);
kvstorageWrite(pFile->pVfs->pStore, zKey, aData);
if( iOfst+iAmt > pFile->szDb ){
@ -589,41 +626,21 @@ static int kvvfsWriteToDb(
return SQLITE_OK;
}
/*
** Write data into the kvvfs-file.
*/
static int kvvfsWrite(
sqlite3_file *pProtoFile,
const void *zBuf,
int iAmt,
sqlite_int64 iOfst
){
int rc;
KVVfsFile *pFile = (KVVfsFile *)pProtoFile;
if( pFile->isJournal ){
rc = kvvfsWriteToJournal(pFile,zBuf,iAmt,iOfst);
}else{
rc = kvvfsWriteToDb(pFile,zBuf,iAmt,iOfst);
}
KVVFS_LOG(("xWrite result: 0x%x\n", rc));
return rc;
}
/*
** Truncate an kvvfs-file.
*/
static int kvvfsTruncate(sqlite3_file *pProtoFile, sqlite_int64 size){
static int kvvfsTruncateJrnl(sqlite3_file *pProtoFile, sqlite_int64 size){
KVVfsFile *pFile = (KVVfsFile *)pProtoFile;
KVVFS_LOG(("xTruncate('journal',%lld)\n", size));
assert( size==0 );
kvstorageDelete(pFile->pVfs->pStore, "jrnl");
sqlite3_free(pFile->aJrnl);
pFile->aJrnl = 0;
pFile->nJrnl = 0;
return SQLITE_OK;
}
static int kvvfsTruncateDb(sqlite3_file *pProtoFile, sqlite_int64 size){
KVVfsFile *pFile = (KVVfsFile *)pProtoFile;
if( pFile->isJournal ){
KVVFS_LOG(("xTruncate('journal',%lld)\n", size));
assert( size==0 );
kvstorageDelete(pFile->pVfs->pStore, "journal");
sqlite3_free(pFile->aJrnl);
pFile->aJrnl = 0;
pFile->nJrnl = 0;
return SQLITE_OK;
}
if( pFile->szDb>size
&& pFile->szPage>0
&& (size % pFile->szPage)==0
@ -634,7 +651,7 @@ static int kvvfsTruncate(sqlite3_file *pProtoFile, sqlite_int64 size){
pgno = 1 + size/pFile->szPage;
pgnoMax = 2 + pFile->szDb/pFile->szPage;
while( pgno<=pgnoMax ){
sqlite3_snprintf(sizeof(zKey), zKey, "pg-%u", pgno);
sqlite3_snprintf(sizeof(zKey), zKey, "%u", pgno);
kvstorageDelete(pFile->pVfs->pStore, zKey);
pgno++;
}
@ -648,20 +665,13 @@ static int kvvfsTruncate(sqlite3_file *pProtoFile, sqlite_int64 size){
/*
** Sync an kvvfs-file.
*/
static int kvvfsSync(sqlite3_file *pProtoFile, int flags){
static int kvvfsSyncJrnl(sqlite3_file *pProtoFile, int flags){
int i, n;
KVVfsFile *pFile = (KVVfsFile *)pProtoFile;
char *zOut;
if( !pFile->isJournal ){
KVVFS_LOG(("xSync('db')\n"));
if( pFile->szDb>0 ){
kvvfsWriteFileSize(pFile, pFile->szDb);
}
return SQLITE_OK;
}
KVVFS_LOG(("xSync('journal')\n"));
if( pFile->nJrnl<=0 ){
return kvvfsTruncate(pProtoFile, 0);
return kvvfsTruncateJrnl(pProtoFile, 0);
}
zOut = sqlite3_malloc64( pFile->nJrnl*2 + 50 );
if( zOut==0 ){
@ -673,29 +683,38 @@ static int kvvfsSync(sqlite3_file *pProtoFile, int flags){
zOut[i++] = 'a' + (n%26);
n /= 26;
}while( n>0 );
zOut[i++] = ' ';
kvvfsEncode(pFile->aJrnl, pFile->nJrnl, &zOut[i]);
kvstorageWrite(pFile->pVfs->pStore, "journal", zOut);
kvstorageWrite(pFile->pVfs->pStore, "jrnl", zOut);
sqlite3_free(zOut);
return SQLITE_OK;
}
static int kvvfsSyncDb(sqlite3_file *pProtoFile, int flags){
KVVfsFile *pFile = (KVVfsFile *)pProtoFile;
KVVFS_LOG(("xSync('db')\n"));
if( pFile->szDb>0 ){
kvvfsWriteFileSize(pFile, pFile->szDb);
}
return SQLITE_OK;
}
/*
** Return the current file-size of an kvvfs-file.
*/
static int kvvfsFileSize(sqlite3_file *pProtoFile, sqlite_int64 *pSize){
static int kvvfsFileSizeJrnl(sqlite3_file *pProtoFile, sqlite_int64 *pSize){
KVVfsFile *pFile = (KVVfsFile *)pProtoFile;
if( pFile->isJournal ){
KVVFS_LOG(("xFileSize('journal')\n"));
*pSize = pFile->nJrnl;
KVVFS_LOG(("xFileSize('journal')\n"));
*pSize = pFile->nJrnl;
return SQLITE_OK;
}
static int kvvfsFileSizeDb(sqlite3_file *pProtoFile, sqlite_int64 *pSize){
KVVfsFile *pFile = (KVVfsFile *)pProtoFile;
KVVFS_LOG(("xFileSize('db')\n"));
if( pFile->szDb>=0 ){
*pSize = pFile->szDb;
}else{
KVVFS_LOG(("xFileSize('db')\n"));
if( pFile->szDb>=0 ){
*pSize = pFile->szDb;
}else{
*pSize = kvvfsReadFileSize(pFile);
}
*pSize = kvvfsReadFileSize(pFile);
}
KVVFS_LOG(("xFileSize: %lld\n", *pSize));
return SQLITE_OK;
}
@ -772,10 +791,15 @@ static int kvvfsOpen(
KVVFS_LOG(("xOpen(\"%s\")\n", zName));
pFile->aJrnl = 0;
pFile->nJrnl = 0;
pFile->isJournal = sqlite3_strglob("*-journal", zName)==0;
if( sqlite3_strglob("*-journal", zName)==0 ){
pFile->isJournal = 1;
pFile->base.pMethods = &kvvfs_jrnl_io_methods;
}else{
pFile->isJournal = 0;
pFile->base.pMethods = &kvvfs_db_io_methods;
}
pFile->szPage = -1;
pFile->szDb = -1;
pFile->base.pMethods = &kvvfs_io_methods;
pFile->pVfs = pVfs;
if( pVfs->pFiles==0 ){
pVfs->pStore = kvstorageOpen();
@ -793,7 +817,7 @@ static int kvvfsOpen(
static int kvvfsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
KVVfsVfs *p = (KVVfsVfs*)pVfs;
if( sqlite3_strglob("*-journal",zPath)==0 ){
kvstorageDelete(p->pStore, "journal");
kvstorageDelete(p->pStore, "jrnl");
}
return SQLITE_OK;
}
@ -811,7 +835,7 @@ static int kvvfsAccess(
KVVfsVfs *pVfs = (KVVfsVfs*)pProtoVfs;
KVVFS_LOG(("xAccess(\"%s\")\n", zPath));
if( sqlite3_strglob("*-journal", zPath)==0 ){
*pResOut = kvstorageRead(pVfs->pStore, "journal", 0, 0)>0;
*pResOut = kvstorageRead(pVfs->pStore, "jrnl", 0, 0)>0;
}else if( sqlite3_strglob("*-wal", zPath)==0 ){
*pResOut = 0;
}else{