/*
** Parameter zSrcData points to a buffer containing the data for
** page iSrcPg from the source database. Copy this data into the
** destination database.
*/
static int backupOnePage(
sqlite3_backup *p, /* Backup handle */
Pgno iSrcPg, /* Source database page to backup */
const u8 *zSrcData, /* Source database page data */
int bUpdate /* True for an update, false otherwise */
){
Pager * const pDestPager = sqlite3BtreePager(p->pDest);
const int nSrcPgsz = sqlite3BtreeGetPageSize(p->pSrc);
int nDestPgsz = sqlite3BtreeGetPageSize(p->pDest);
const int nCopy = MIN(nSrcPgsz, nDestPgsz);
const i64 iEnd = (i64)iSrcPg*(i64)nSrcPgsz;
#ifdef SQLITE_HAS_CODEC
/* Use BtreeGetReserveNoMutex() for the source b-tree, as although it is
** guaranteed that the shared-mutex is held by this thread, handle
** p->pSrc may not actually be the owner. */
int nSrcReserve = sqlite3BtreeGetReserveNoMutex(p->pSrc);
int nDestReserve = sqlite3BtreeGetOptimalReserve(p->pDest);
#endif
int rc = SQLITE_OK;
i64 iOff;
assert( sqlite3BtreeGetReserveNoMutex(p->pSrc)>=0 );
assert( p->bDestLocked );
assert( !isFatalError(p->rc) );
assert( iSrcPg!=PENDING_BYTE_PAGE(p->pSrc->pBt) );
assert( zSrcData );
/* Catch the case where the destination is an in-memory database and the
** page sizes of the source and destination differ.
*/
if( nSrcPgsz!=nDestPgsz && sqlite3PagerIsMemdb(pDestPager) ){
rc = SQLITE_READONLY;
}
#ifdef SQLITE_HAS_CODEC
/* Backup is not possible if the page size of the destination is changing
** and a codec is in use.
*/
if( nSrcPgsz!=nDestPgsz && sqlite3PagerGetCodec(pDestPager)!=0 ){
rc = SQLITE_READONLY;
}
/* Backup is not possible if the number of bytes of reserve space differ
** between source and destination. If there is a difference, try to
** fix the destination to agree with the source. If that is not possible,
** then the backup cannot proceed.
*/
if( nSrcReserve!=nDestReserve ){
u32 newPgsz = nSrcPgsz;
rc = sqlite3PagerSetPagesize(pDestPager, &newPgsz, nSrcReserve);
if( rc==SQLITE_OK && newPgsz!=nSrcPgsz ) rc = SQLITE_READONLY;
}
#endif
/* This loop runs once for each destination page spanned by the source
** page. For each iteration, variable iOff is set to the byte offset
** of the destination page.
*/
for(iOff=iEnd-(i64)nSrcPgsz; rc==SQLITE_OK && iOff<iEnd; iOff+=nDestPgsz){
DbPage *pDestPg = 0;
Pgno iDest = (Pgno)(iOff/nDestPgsz)+1;
if( iDest==PENDING_BYTE_PAGE(p->pDest->pBt) ) continue;
if( SQLITE_OK==(rc = sqlite3PagerGet(pDestPager, iDest, &pDestPg, 0))
&& SQLITE_OK==(rc = sqlite3PagerWrite(pDestPg))
){
const u8 *zIn = &zSrcData[iOff%nSrcPgsz];
u8 *zDestData = sqlite3PagerGetData(pDestPg);
u8 *zOut = &zDestData[iOff%nDestPgsz];
/* Copy the data from the source page into the destination page.
** Then clear the Btree layer MemPage.isInit flag. Both this module
** and the pager code use this trick (clearing the first byte
** of the page 'extra' space to invalidate the Btree layers
** cached parse of the page). MemPage.isInit is marked
** "MUST BE FIRST" for this purpose.
*/
memcpy(zOut, zIn, nCopy);
((u8 *)sqlite3PagerGetExtra(pDestPg))[0] = 0;
if( iOff==0 && bUpdate==0 ){
sqlite3Put4byte(&zOut[28], sqlite3BtreeLastPage(p->pSrc));
}
}
sqlite3PagerUnref(pDestPg);
}
return rc;
}
/*
** An SQL user-function registered to do the work of an ATTACH statement. The
** three arguments to the function come directly from an attach statement:
**
** ATTACH DATABASE x AS y KEY z
**
** SELECT sqlite_attach(x, y, z)
**
** If the optional "KEY z" syntax is omitted, an SQL NULL is passed as the
** third argument.
*/
static void attachFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **argv
){
int i;
int rc = 0;
sqlite3 *db = sqlite3_context_db_handle(context);
const char *zName;
const char *zFile;
char *zPath = 0;
char *zErr = 0;
unsigned int flags;
Db *aNew;
char *zErrDyn = 0;
sqlite3_vfs *pVfs;
UNUSED_PARAMETER(NotUsed);
zFile = (const char *)sqlite3_value_text(argv[0]);
zName = (const char *)sqlite3_value_text(argv[1]);
if( zFile==0 ) zFile = "";
if( zName==0 ) zName = "";
/* Check for the following errors:
**
** * Too many attached databases,
** * Transaction currently open
** * Specified database name already being used.
*/
if( db->nDb>=db->aLimit[SQLITE_LIMIT_ATTACHED]+2 ){
zErrDyn = sqlite3MPrintf(db, "too many attached databases - max %d",
db->aLimit[SQLITE_LIMIT_ATTACHED]
);
goto attach_error;
}
if( !db->autoCommit ){
zErrDyn = sqlite3MPrintf(db, "cannot ATTACH database within transaction");
goto attach_error;
}
for(i=0; i<db->nDb; i++){
char *z = db->aDb[i].zName;
assert( z && zName );
if( sqlite3StrICmp(z, zName)==0 ){
zErrDyn = sqlite3MPrintf(db, "database %s is already in use", zName);
goto attach_error;
}
}
/* Allocate the new entry in the db->aDb[] array and initialize the schema
** hash tables.
*/
if( db->aDb==db->aDbStatic ){
aNew = sqlite3DbMallocRaw(db, sizeof(db->aDb[0])*3 );
if( aNew==0 ) return;
memcpy(aNew, db->aDb, sizeof(db->aDb[0])*2);
}else{
aNew = sqlite3DbRealloc(db, db->aDb, sizeof(db->aDb[0])*(db->nDb+1) );
if( aNew==0 ) return;
}
db->aDb = aNew;
aNew = &db->aDb[db->nDb];
memset(aNew, 0, sizeof(*aNew));
/* Open the database file. If the btree is successfully opened, use
** it to obtain the database schema. At this point the schema may
** or may not be initialized.
*/
flags = db->openFlags;
rc = sqlite3ParseUri(db->pVfs->zName, zFile, &flags, &pVfs, &zPath, &zErr);
if( rc!=SQLITE_OK ){
if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
sqlite3_result_error(context, zErr, -1);
sqlite3_free(zErr);
return;
}
assert( pVfs );
flags |= SQLITE_OPEN_MAIN_DB;
rc = sqlite3BtreeOpen(pVfs, zPath, db, &aNew->pBt, 0, flags);
sqlite3_free( zPath );
db->nDb++;
if( rc==SQLITE_CONSTRAINT ){
rc = SQLITE_ERROR;
zErrDyn = sqlite3MPrintf(db, "database is already attached");
}else if( rc==SQLITE_OK ){
Pager *pPager;
aNew->pSchema = sqlite3SchemaGet(db, aNew->pBt);
if( !aNew->pSchema ){
rc = SQLITE_NOMEM;
}else if( aNew->pSchema->file_format && aNew->pSchema->enc!=ENC(db) ){
zErrDyn = sqlite3MPrintf(db,
"attached databases must use the same text encoding as main database");
rc = SQLITE_ERROR;
}
sqlite3BtreeEnter(aNew->pBt);
pPager = sqlite3BtreePager(aNew->pBt);
sqlite3PagerLockingMode(pPager, db->dfltLockMode);
sqlite3BtreeSecureDelete(aNew->pBt,
sqlite3BtreeSecureDelete(db->aDb[0].pBt,-1) );
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
sqlite3BtreeSetPagerFlags(aNew->pBt, 3 | (db->flags & PAGER_FLAGS_MASK));
#endif
sqlite3BtreeLeave(aNew->pBt);
}
aNew->safety_level = 3;
aNew->zName = sqlite3DbStrDup(db, zName);
if( rc==SQLITE_OK && aNew->zName==0 ){
rc = SQLITE_NOMEM;
}
#ifdef SQLITE_HAS_CODEC
if( rc==SQLITE_OK ){
extern int sqlite3CodecAttach(sqlite3*, int, const void*, int);
extern void sqlite3CodecGetKey(sqlite3*, int, void**, int*);
int nKey;
char *zKey;
int t = sqlite3_value_type(argv[2]);
switch( t ){
case SQLITE_INTEGER:
case SQLITE_FLOAT:
zErrDyn = sqlite3DbStrDup(db, "Invalid key value");
rc = SQLITE_ERROR;
break;
case SQLITE_TEXT:
case SQLITE_BLOB:
nKey = sqlite3_value_bytes(argv[2]);
zKey = (char *)sqlite3_value_blob(argv[2]);
rc = sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);
break;
case SQLITE_NULL:
/* No key specified. Use the key from the main database */
sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
if( nKey>0 || sqlite3BtreeGetOptimalReserve(db->aDb[0].pBt)>0 ){
rc = sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);
}
break;
}
}
#endif
/* If the file was opened successfully, read the schema for the new database.
** If this fails, or if opening the file failed, then close the file and
** remove the entry from the db->aDb[] array. i.e. put everything back the way
** we found it.
*/
if( rc==SQLITE_OK ){
sqlite3BtreeEnterAll(db);
rc = sqlite3Init(db, &zErrDyn);
sqlite3BtreeLeaveAll(db);
}
#ifdef SQLITE_USER_AUTHENTICATION
if( rc==SQLITE_OK ){
u8 newAuth = 0;
rc = sqlite3UserAuthCheckLogin(db, zName, &newAuth);
if( newAuth<db->auth.authLevel ){
rc = SQLITE_AUTH_USER;
}
}
#endif
if( rc ){
int iDb = db->nDb - 1;
assert( iDb>=2 );
if( db->aDb[iDb].pBt ){
sqlite3BtreeClose(db->aDb[iDb].pBt);
db->aDb[iDb].pBt = 0;
db->aDb[iDb].pSchema = 0;
}
sqlite3ResetAllSchemasOfConnection(db);
db->nDb = iDb;
if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
db->mallocFailed = 1;
sqlite3DbFree(db, zErrDyn);
zErrDyn = sqlite3MPrintf(db, "out of memory");
}else if( zErrDyn==0 ){
zErrDyn = sqlite3MPrintf(db, "unable to open database: %s", zFile);
}
goto attach_error;
}
return;
attach_error:
/* Return an error if we get here */
if( zErrDyn ){
sqlite3_result_error(context, zErrDyn, -1);
sqlite3DbFree(db, zErrDyn);
}
if( rc ) sqlite3_result_error_code(context, rc);
}
/*
** This routine implements the OP_Vacuum opcode of the VDBE.
*/
int sqlite3RunVacuum(
char **pzErrMsg, /* Write error message here */
sqlite3 *db, /* Database connection */
int iDb, /* Which attached DB to vacuum */
sqlite3_value *pOut /* Write results here, if not NULL */
){
int rc = SQLITE_OK; /* Return code from service routines */
Btree *pMain; /* The database being vacuumed */
Btree *pTemp; /* The temporary database we vacuum into */
u32 saved_mDbFlags; /* Saved value of db->mDbFlags */
u64 saved_flags; /* Saved value of db->flags */
int saved_nChange; /* Saved value of db->nChange */
int saved_nTotalChange; /* Saved value of db->nTotalChange */
u8 saved_mTrace; /* Saved trace settings */
Db *pDb = 0; /* Database to detach at end of vacuum */
int isMemDb; /* True if vacuuming a :memory: database */
int nRes; /* Bytes of reserved space at the end of each page */
int nDb; /* Number of attached databases */
const char *zDbMain; /* Schema name of database to vacuum */
const char *zOut; /* Name of output file */
if( !db->autoCommit ){
sqlite3SetString(pzErrMsg, db, "cannot VACUUM from within a transaction");
return SQLITE_ERROR;
}
if( db->nVdbeActive>1 ){
sqlite3SetString(pzErrMsg, db,"cannot VACUUM - SQL statements in progress");
return SQLITE_ERROR;
}
if( pOut ){
if( sqlite3_value_type(pOut)!=SQLITE_TEXT ){
sqlite3SetString(pzErrMsg, db, "non-text filename");
return SQLITE_ERROR;
}
zOut = (const char*)sqlite3_value_text(pOut);
}else{
zOut = "";
}
/* Save the current value of the database flags so that it can be
** restored before returning. Then set the writable-schema flag, and
** disable CHECK and foreign key constraints. */
saved_flags = db->flags;
saved_mDbFlags = db->mDbFlags;
saved_nChange = db->nChange;
saved_nTotalChange = db->nTotalChange;
saved_mTrace = db->mTrace;
db->flags |= SQLITE_WriteSchema | SQLITE_IgnoreChecks;
db->mDbFlags |= DBFLAG_PreferBuiltin | DBFLAG_Vacuum;
db->flags &= ~(u64)(SQLITE_ForeignKeys | SQLITE_ReverseOrder
| SQLITE_Defensive | SQLITE_CountRows);
db->mTrace = 0;
zDbMain = db->aDb[iDb].zDbSName;
pMain = db->aDb[iDb].pBt;
isMemDb = sqlite3PagerIsMemdb(sqlite3BtreePager(pMain));
/* Attach the temporary database as 'vacuum_db'. The synchronous pragma
** can be set to 'off' for this file, as it is not recovered if a crash
** occurs anyway. The integrity of the database is maintained by a
** (possibly synchronous) transaction opened on the main database before
** sqlite3BtreeCopyFile() is called.
**
** An optimisation would be to use a non-journaled pager.
** (Later:) I tried setting "PRAGMA vacuum_db.journal_mode=OFF" but
** that actually made the VACUUM run slower. Very little journalling
** actually occurs when doing a vacuum since the vacuum_db is initially
** empty. Only the journal header is written. Apparently it takes more
** time to parse and run the PRAGMA to turn journalling off than it does
** to write the journal header file.
*/
nDb = db->nDb;
rc = execSqlF(db, pzErrMsg, "ATTACH %Q AS vacuum_db", zOut);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
assert( (db->nDb-1)==nDb );
pDb = &db->aDb[nDb];
assert( strcmp(pDb->zDbSName,"vacuum_db")==0 );
pTemp = pDb->pBt;
if( pOut ){
sqlite3_file *id = sqlite3PagerFile(sqlite3BtreePager(pTemp));
i64 sz = 0;
if( id->pMethods!=0 && (sqlite3OsFileSize(id, &sz)!=SQLITE_OK || sz>0) ){
rc = SQLITE_ERROR;
sqlite3SetString(pzErrMsg, db, "output file already exists");
goto end_of_vacuum;
}
}
nRes = sqlite3BtreeGetOptimalReserve(pMain);
/* A VACUUM cannot change the pagesize of an encrypted database. */
#ifdef SQLITE_HAS_CODEC
if( db->nextPagesize ){
extern void sqlite3CodecGetKey(sqlite3*, int, void**, int*);
int nKey;
char *zKey;
sqlite3CodecGetKey(db, iDb, (void**)&zKey, &nKey);
if( nKey ) db->nextPagesize = 0;
}
#endif
sqlite3BtreeSetCacheSize(pTemp, db->aDb[iDb].pSchema->cache_size);
sqlite3BtreeSetSpillSize(pTemp, sqlite3BtreeSetSpillSize(pMain,0));
sqlite3BtreeSetPagerFlags(pTemp, PAGER_SYNCHRONOUS_OFF|PAGER_CACHESPILL);
/* Begin a transaction and take an exclusive lock on the main database
** file. This is done before the sqlite3BtreeGetPageSize(pMain) call below,
** to ensure that we do not try to change the page-size on a WAL database.
*/
rc = execSql(db, pzErrMsg, "BEGIN");
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeBeginTrans(pMain, pOut==0 ? 2 : 0, 0);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Do not attempt to change the page size for a WAL database */
if( sqlite3PagerGetJournalMode(sqlite3BtreePager(pMain))
==PAGER_JOURNALMODE_WAL ){
db->nextPagesize = 0;
}
if( sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain), nRes, 0)
|| (!isMemDb && sqlite3BtreeSetPageSize(pTemp, db->nextPagesize, nRes, 0))
|| NEVER(db->mallocFailed)
){
rc = SQLITE_NOMEM_BKPT;
goto end_of_vacuum;
}
#ifndef SQLITE_OMIT_AUTOVACUUM
sqlite3BtreeSetAutoVacuum(pTemp, db->nextAutovac>=0 ? db->nextAutovac :
sqlite3BtreeGetAutoVacuum(pMain));
#endif
/* Query the schema of the main database. Create a mirror schema
** in the temporary database.
*/
db->init.iDb = nDb; /* force new CREATE statements into vacuum_db */
rc = execSqlF(db, pzErrMsg,
"SELECT sql FROM \"%w\".sqlite_master"
" WHERE type='table'AND name<>'sqlite_sequence'"
" AND coalesce(rootpage,1)>0",
zDbMain
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = execSqlF(db, pzErrMsg,
"SELECT sql FROM \"%w\".sqlite_master"
" WHERE type='index'",
zDbMain
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
db->init.iDb = 0;
/* Loop through the tables in the main database. For each, do
** an "INSERT INTO vacuum_db.xxx SELECT * FROM main.xxx;" to copy
** the contents to the temporary database.
*/
rc = execSqlF(db, pzErrMsg,
"SELECT'INSERT INTO vacuum_db.'||quote(name)"
"||' SELECT*FROM\"%w\".'||quote(name)"
"FROM vacuum_db.sqlite_master "
"WHERE type='table'AND coalesce(rootpage,1)>0",
zDbMain
);
assert( (db->mDbFlags & DBFLAG_Vacuum)!=0 );
db->mDbFlags &= ~DBFLAG_Vacuum;
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Copy the triggers, views, and virtual tables from the main database
** over to the temporary database. None of these objects has any
** associated storage, so all we have to do is copy their entries
** from the SQLITE_MASTER table.
*/
rc = execSqlF(db, pzErrMsg,
"INSERT INTO vacuum_db.sqlite_master"
" SELECT*FROM \"%w\".sqlite_master"
" WHERE type IN('view','trigger')"
" OR(type='table'AND rootpage=0)",
zDbMain
);
if( rc ) goto end_of_vacuum;
/* At this point, there is a write transaction open on both the
** vacuum database and the main database. Assuming no error occurs,
** both transactions are closed by this block - the main database
** transaction by sqlite3BtreeCopyFile() and the other by an explicit
** call to sqlite3BtreeCommit().
*/
{
u32 meta;
int i;
/* This array determines which meta meta values are preserved in the
** vacuum. Even entries are the meta value number and odd entries
** are an increment to apply to the meta value after the vacuum.
** The increment is used to increase the schema cookie so that other
** connections to the same database will know to reread the schema.
*/
static const unsigned char aCopy[] = {
BTREE_SCHEMA_VERSION, 1, /* Add one to the old schema cookie */
BTREE_DEFAULT_CACHE_SIZE, 0, /* Preserve the default page cache size */
BTREE_TEXT_ENCODING, 0, /* Preserve the text encoding */
BTREE_USER_VERSION, 0, /* Preserve the user version */
BTREE_APPLICATION_ID, 0, /* Preserve the application id */
};
assert( 1==sqlite3BtreeIsInTrans(pTemp) );
assert( pOut!=0 || 1==sqlite3BtreeIsInTrans(pMain) );
/* Copy Btree meta values */
for(i=0; i<ArraySize(aCopy); i+=2){
/* GetMeta() and UpdateMeta() cannot fail in this context because
** we already have page 1 loaded into cache and marked dirty. */
sqlite3BtreeGetMeta(pMain, aCopy[i], &meta);
rc = sqlite3BtreeUpdateMeta(pTemp, aCopy[i], meta+aCopy[i+1]);
if( NEVER(rc!=SQLITE_OK) ) goto end_of_vacuum;
}
if( pOut==0 ){
rc = sqlite3BtreeCopyFile(pMain, pTemp);
}
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeCommit(pTemp);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
#ifndef SQLITE_OMIT_AUTOVACUUM
if( pOut==0 ){
sqlite3BtreeSetAutoVacuum(pMain, sqlite3BtreeGetAutoVacuum(pTemp));
}
#endif
}
assert( rc==SQLITE_OK );
if( pOut==0 ){
rc = sqlite3BtreeSetPageSize(pMain, sqlite3BtreeGetPageSize(pTemp), nRes,1);
}
end_of_vacuum:
/* Restore the original value of db->flags */
db->init.iDb = 0;
db->mDbFlags = saved_mDbFlags;
db->flags = saved_flags;
db->nChange = saved_nChange;
db->nTotalChange = saved_nTotalChange;
db->mTrace = saved_mTrace;
sqlite3BtreeSetPageSize(pMain, -1, -1, 1);
/* Currently there is an SQL level transaction open on the vacuum
** database. No locks are held on any other files (since the main file
** was committed at the btree level). So it safe to end the transaction
** by manually setting the autoCommit flag to true and detaching the
** vacuum database. The vacuum_db journal file is deleted when the pager
** is closed by the DETACH.
*/
db->autoCommit = 1;
if( pDb ){
sqlite3BtreeClose(pDb->pBt);
pDb->pBt = 0;
pDb->pSchema = 0;
}
/* This both clears the schemas and reduces the size of the db->aDb[]
** array. */
sqlite3ResetAllSchemasOfConnection(db);
return rc;
}
