/* ** Check that there is no open read-transaction on the b-tree passed as the ** second argument. If there is not, return SQLITE_OK. Otherwise, if there ** is an open read-transaction, return SQLITE_ERROR and leave an error ** message in database handle db. */ static int checkReadTransaction(sqlite3 *db, Btree *p){ if( sqlite3BtreeIsInReadTrans(p) ){ sqlite3ErrorWithMsg(db, SQLITE_ERROR, "destination database is in use"); return SQLITE_ERROR; } return SQLITE_OK; }
/* ** Invalidate temp storage, either when the temp storage is changed ** from default, or when 'file' and the temp_store_directory has changed */ static int invalidateTempStorage(Parse *pParse){ sqlite3 *db = pParse->db; if( db->aDb[1].pBt!=0 ){ if( !db->autoCommit || sqlite3BtreeIsInReadTrans(db->aDb[1].pBt) ){ sqlite3ErrorMsg(pParse, "temporary storage cannot be changed " "from within a transaction"); return SQLITE_ERROR; } sqlite3BtreeClose(db->aDb[1].pBt); db->aDb[1].pBt = 0; sqlite3ResetInternalSchema(db, 0); } return SQLITE_OK; }
/* ** An SQL user-function registered to do the work of an DETACH statement. The ** three arguments to the function come directly from a detach statement: ** ** DETACH DATABASE x ** ** SELECT sqlite_detach(x) */ static void detachFunc( sqlite3_context *context, int NotUsed, sqlite3_value **argv ){ const char *zName = (const char *)sqlite3_value_text(argv[0]); sqlite3 *db = sqlite3_context_db_handle(context); int i; Db *pDb = 0; char zErr[128]; UNUSED_PARAMETER(NotUsed); if( zName==0 ) zName = ""; for(i=0; i<db->nDb; i++){ pDb = &db->aDb[i]; if( pDb->pBt==0 ) continue; if( sqlite3StrICmp(pDb->zName, zName)==0 ) break; } if( i>=db->nDb ){ sqlite3_snprintf(sizeof(zErr),zErr, "no such database: %s", zName); goto detach_error; } if( i<2 ){ sqlite3_snprintf(sizeof(zErr),zErr, "cannot detach database %s", zName); goto detach_error; } if( !db->autoCommit ){ sqlite3_snprintf(sizeof(zErr), zErr, "cannot DETACH database within transaction"); goto detach_error; } if( sqlite3BtreeIsInReadTrans(pDb->pBt) || sqlite3BtreeIsInBackup(pDb->pBt) ){ sqlite3_snprintf(sizeof(zErr),zErr, "database %s is locked", zName); goto detach_error; } sqlite3BtreeClose(pDb->pBt); pDb->pBt = 0; pDb->pSchema = 0; sqlite3ResetInternalSchema(db, 0); return; detach_error: sqlite3_result_error(context, zErr, -1); }
/* ** Check schema cookies in all databases. If any cookie is out ** of date set pParse->rc to SQLITE_SCHEMA. If all schema cookies ** make no changes to pParse->rc. */ static void schemaIsValid(Parse *pParse){ sqlite3 *db = pParse->db; int iDb; int rc; int cookie; assert( pParse->checkSchema ); assert( sqlite3_mutex_held(db->mutex) ); for(iDb=0; iDb<db->nDb; iDb++){ int openedTransaction = 0; /* True if a transaction is opened */ Btree *pBt = db->aDb[iDb].pBt; /* Btree database to read cookie from */ if( pBt==0 ) continue; /* If there is not already a read-only (or read-write) transaction opened ** on the b-tree database, open one now. If a transaction is opened, it ** will be closed immediately after reading the meta-value. */ if( !sqlite3BtreeIsInReadTrans(pBt) ){ rc = sqlite3BtreeBeginTrans(pBt, 0); if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){ db->mallocFailed = 1; } if( rc!=SQLITE_OK ) return; openedTransaction = 1; } /* Read the schema cookie from the database. If it does not match the ** value stored as part of the in the in-memory schema representation, ** set Parse.rc to SQLITE_SCHEMA. */ sqlite3BtreeGetMeta(pBt, BTREE_SCHEMA_VERSION, (u32 *)&cookie); if( cookie!=db->aDb[iDb].pSchema->schema_cookie ){ pParse->rc = SQLITE_SCHEMA; } /* Close the transaction, if one was opened. */ if( openedTransaction ){ sqlite3BtreeCommit(pBt); } } }
/* ** Copy nPage pages from the source b-tree to the destination. */ int sqlite3_backup_step(sqlite3_backup *p, int nPage){ int rc; int destMode; /* Destination journal mode */ int pgszSrc = 0; /* Source page size */ int pgszDest = 0; /* Destination page size */ #ifdef SQLITE_ENABLE_API_ARMOR if( p==0 ) return SQLITE_MISUSE_BKPT; #endif sqlite3_mutex_enter(p->pSrcDb->mutex); sqlite3BtreeEnter(p->pSrc); if( p->pDestDb ){ sqlite3_mutex_enter(p->pDestDb->mutex); } rc = p->rc; if( !isFatalError(rc) ){ Pager * const pSrcPager = sqlite3BtreePager(p->pSrc); /* Source pager */ Pager * const pDestPager = sqlite3BtreePager(p->pDest); /* Dest pager */ int ii; /* Iterator variable */ int nSrcPage = -1; /* Size of source db in pages */ int bCloseTrans = 0; /* True if src db requires unlocking */ /* If the source pager is currently in a write-transaction, return ** SQLITE_BUSY immediately. */ if( p->pDestDb && p->pSrc->pBt->inTransaction==TRANS_WRITE ){ rc = SQLITE_BUSY; }else{ rc = SQLITE_OK; } /* If there is no open read-transaction on the source database, open ** one now. If a transaction is opened here, then it will be closed ** before this function exits. */ if( rc==SQLITE_OK && 0==sqlite3BtreeIsInReadTrans(p->pSrc) ){ rc = sqlite3BtreeBeginTrans(p->pSrc, 0, 0); bCloseTrans = 1; } /* If the destination database has not yet been locked (i.e. if this ** is the first call to backup_step() for the current backup operation), ** try to set its page size to the same as the source database. This ** is especially important on ZipVFS systems, as in that case it is ** not possible to create a database file that uses one page size by ** writing to it with another. */ if( p->bDestLocked==0 && rc==SQLITE_OK && setDestPgsz(p)==SQLITE_NOMEM ){ rc = SQLITE_NOMEM; } /* Lock the destination database, if it is not locked already. */ if( SQLITE_OK==rc && p->bDestLocked==0 && SQLITE_OK==(rc = sqlite3BtreeBeginTrans(p->pDest, 2, (int*)&p->iDestSchema)) ){ p->bDestLocked = 1; } /* Do not allow backup if the destination database is in WAL mode ** and the page sizes are different between source and destination */ pgszSrc = sqlite3BtreeGetPageSize(p->pSrc); pgszDest = sqlite3BtreeGetPageSize(p->pDest); destMode = sqlite3PagerGetJournalMode(sqlite3BtreePager(p->pDest)); if( SQLITE_OK==rc && destMode==PAGER_JOURNALMODE_WAL && pgszSrc!=pgszDest ){ rc = SQLITE_READONLY; } /* Now that there is a read-lock on the source database, query the ** source pager for the number of pages in the database. */ nSrcPage = (int)sqlite3BtreeLastPage(p->pSrc); assert( nSrcPage>=0 ); for(ii=0; (nPage<0 || ii<nPage) && p->iNext<=(Pgno)nSrcPage && !rc; ii++){ const Pgno iSrcPg = p->iNext; /* Source page number */ if( iSrcPg!=PENDING_BYTE_PAGE(p->pSrc->pBt) ){ DbPage *pSrcPg; /* Source page object */ rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg,PAGER_GET_READONLY); if( rc==SQLITE_OK ){ rc = backupOnePage(p, iSrcPg, sqlite3PagerGetData(pSrcPg), 0); sqlite3PagerUnref(pSrcPg); } } p->iNext++; } if( rc==SQLITE_OK ){ p->nPagecount = nSrcPage; p->nRemaining = nSrcPage+1-p->iNext; if( p->iNext>(Pgno)nSrcPage ){ rc = SQLITE_DONE; }else if( !p->isAttached ){ attachBackupObject(p); } } /* Update the schema version field in the destination database. This ** is to make sure that the schema-version really does change in ** the case where the source and destination databases have the ** same schema version. */ if( rc==SQLITE_DONE ){ if( nSrcPage==0 ){ rc = sqlite3BtreeNewDb(p->pDest); nSrcPage = 1; } if( rc==SQLITE_OK || rc==SQLITE_DONE ){ rc = sqlite3BtreeUpdateMeta(p->pDest,1,p->iDestSchema+1); } if( rc==SQLITE_OK ){ if( p->pDestDb ){ sqlite3ResetAllSchemasOfConnection(p->pDestDb); } if( destMode==PAGER_JOURNALMODE_WAL ){ rc = sqlite3BtreeSetVersion(p->pDest, 2); } } if( rc==SQLITE_OK ){ int nDestTruncate; /* Set nDestTruncate to the final number of pages in the destination ** database. The complication here is that the destination page ** size may be different to the source page size. ** ** If the source page size is smaller than the destination page size, ** round up. In this case the call to sqlite3OsTruncate() below will ** fix the size of the file. However it is important to call ** sqlite3PagerTruncateImage() here so that any pages in the ** destination file that lie beyond the nDestTruncate page mark are ** journalled by PagerCommitPhaseOne() before they are destroyed ** by the file truncation. */ assert( pgszSrc==sqlite3BtreeGetPageSize(p->pSrc) ); assert( pgszDest==sqlite3BtreeGetPageSize(p->pDest) ); if( pgszSrc<pgszDest ){ int ratio = pgszDest/pgszSrc; nDestTruncate = (nSrcPage+ratio-1)/ratio; if( nDestTruncate==(int)PENDING_BYTE_PAGE(p->pDest->pBt) ){ nDestTruncate--; } }else{ nDestTruncate = nSrcPage * (pgszSrc/pgszDest); } assert( nDestTruncate>0 ); if( pgszSrc<pgszDest ){ /* If the source page-size is smaller than the destination page-size, ** two extra things may need to happen: ** ** * The destination may need to be truncated, and ** ** * Data stored on the pages immediately following the ** pending-byte page in the source database may need to be ** copied into the destination database. */ const i64 iSize = (i64)pgszSrc * (i64)nSrcPage; sqlite3_file * const pFile = sqlite3PagerFile(pDestPager); Pgno iPg; int nDstPage; i64 iOff; i64 iEnd; assert( pFile ); assert( nDestTruncate==0 || (i64)nDestTruncate*(i64)pgszDest >= iSize || ( nDestTruncate==(int)(PENDING_BYTE_PAGE(p->pDest->pBt)-1) && iSize>=PENDING_BYTE && iSize<=PENDING_BYTE+pgszDest )); /* This block ensures that all data required to recreate the original ** database has been stored in the journal for pDestPager and the ** journal synced to disk. So at this point we may safely modify ** the database file in any way, knowing that if a power failure ** occurs, the original database will be reconstructed from the ** journal file. */ sqlite3PagerPagecount(pDestPager, &nDstPage); for(iPg=nDestTruncate; rc==SQLITE_OK && iPg<=(Pgno)nDstPage; iPg++){ if( iPg!=PENDING_BYTE_PAGE(p->pDest->pBt) ){ DbPage *pPg; rc = sqlite3PagerGet(pDestPager, iPg, &pPg, 0); if( rc==SQLITE_OK ){ rc = sqlite3PagerWrite(pPg); sqlite3PagerUnref(pPg); } } } if( rc==SQLITE_OK ){ rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 1); } /* Write the extra pages and truncate the database file as required */ iEnd = MIN(PENDING_BYTE + pgszDest, iSize); for( iOff=PENDING_BYTE+pgszSrc; rc==SQLITE_OK && iOff<iEnd; iOff+=pgszSrc ){ PgHdr *pSrcPg = 0; const Pgno iSrcPg = (Pgno)((iOff/pgszSrc)+1); rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg, 0); if( rc==SQLITE_OK ){ u8 *zData = sqlite3PagerGetData(pSrcPg); rc = sqlite3OsWrite(pFile, zData, pgszSrc, iOff); } sqlite3PagerUnref(pSrcPg); } if( rc==SQLITE_OK ){ rc = backupTruncateFile(pFile, iSize); } /* Sync the database file to disk. */ if( rc==SQLITE_OK ){ rc = sqlite3PagerSync(pDestPager, 0); } }else{ sqlite3PagerTruncateImage(pDestPager, nDestTruncate); rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 0); } /* Finish committing the transaction to the destination database. */ if( SQLITE_OK==rc && SQLITE_OK==(rc = sqlite3BtreeCommitPhaseTwo(p->pDest, 0)) ){ rc = SQLITE_DONE; } } } /* If bCloseTrans is true, then this function opened a read transaction ** on the source database. Close the read transaction here. There is ** no need to check the return values of the btree methods here, as ** "committing" a read-only transaction cannot fail. */ if( bCloseTrans ){ TESTONLY( int rc2 ); TESTONLY( rc2 = ) sqlite3BtreeCommitPhaseOne(p->pSrc, 0); TESTONLY( rc2 |= ) sqlite3BtreeCommitPhaseTwo(p->pSrc, 0); assert( rc2==SQLITE_OK ); } if( rc==SQLITE_IOERR_NOMEM ){ rc = SQLITE_NOMEM_BKPT; } p->rc = rc; }
/* ** Attempt to read the database schema and initialize internal ** data structures for a single database file. The index of the ** database file is given by iDb. iDb==0 is used for the main ** database. iDb==1 should never be used. iDb>=2 is used for ** auxiliary databases. Return one of the SQLITE_ error codes to ** indicate success or failure. */ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){ int rc; int i; int size; Table *pTab; Db *pDb; char const *azArg[4]; int meta[5]; InitData initData; char const *zMasterSchema; char const *zMasterName = SCHEMA_TABLE(iDb); int openedTransaction = 0; /* ** The master database table has a structure like this */ static const char master_schema[] = "CREATE TABLE sqlite_master(\n" " type text,\n" " name text,\n" " tbl_name text,\n" " rootpage integer,\n" " sql text\n" ")" ; #ifndef SQLITE_OMIT_TEMPDB static const char temp_master_schema[] = "CREATE TEMP TABLE sqlite_temp_master(\n" " type text,\n" " name text,\n" " tbl_name text,\n" " rootpage integer,\n" " sql text\n" ")" ; #else #define temp_master_schema 0 #endif assert( iDb>=0 && iDb<db->nDb ); assert( db->aDb[iDb].pSchema ); assert( sqlite3_mutex_held(db->mutex) ); assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) ); /* zMasterSchema and zInitScript are set to point at the master schema ** and initialisation script appropriate for the database being ** initialised. zMasterName is the name of the master table. */ if( !OMIT_TEMPDB && iDb==1 ){ zMasterSchema = temp_master_schema; }else{ zMasterSchema = master_schema; } zMasterName = SCHEMA_TABLE(iDb); /* Construct the schema tables. */ azArg[0] = zMasterName; azArg[1] = "1"; azArg[2] = zMasterSchema; azArg[3] = 0; initData.db = db; initData.iDb = iDb; initData.rc = SQLITE_OK; initData.pzErrMsg = pzErrMsg; (void)sqlite3SafetyOff(db); sqlite3InitCallback(&initData, 3, (char **)azArg, 0); (void)sqlite3SafetyOn(db); if( initData.rc ){ rc = initData.rc; goto error_out; } pTab = sqlite3FindTable(db, zMasterName, db->aDb[iDb].zName); if( ALWAYS(pTab) ){ pTab->tabFlags |= TF_Readonly; } /* Create a cursor to hold the database open */ pDb = &db->aDb[iDb]; if( pDb->pBt==0 ){ if( !OMIT_TEMPDB && ALWAYS(iDb==1) ){ DbSetProperty(db, 1, DB_SchemaLoaded); } return SQLITE_OK; } /* If there is not already a read-only (or read-write) transaction opened ** on the b-tree database, open one now. If a transaction is opened, it ** will be closed before this function returns. */ sqlite3BtreeEnter(pDb->pBt); if( !sqlite3BtreeIsInReadTrans(pDb->pBt) ){ rc = sqlite3BtreeBeginTrans(pDb->pBt, 0); if( rc!=SQLITE_OK ){ sqlite3SetString(pzErrMsg, db, "%s", sqlite3ErrStr(rc)); goto initone_error_out; } openedTransaction = 1; } /* Get the database meta information. ** ** Meta values are as follows: ** meta[0] Schema cookie. Changes with each schema change. ** meta[1] File format of schema layer. ** meta[2] Size of the page cache. ** meta[3] Largest rootpage (auto/incr_vacuum mode) ** meta[4] Db text encoding. 1:UTF-8 2:UTF-16LE 3:UTF-16BE ** meta[5] User version ** meta[6] Incremental vacuum mode ** meta[7] unused ** meta[8] unused ** meta[9] unused ** ** Note: The #defined SQLITE_UTF* symbols in sqliteInt.h correspond to ** the possible values of meta[4]. */ for(i=0; i<ArraySize(meta); i++){ sqlite3BtreeGetMeta(pDb->pBt, i+1, (u32 *)&meta[i]); } pDb->pSchema->schema_cookie = meta[BTREE_SCHEMA_VERSION-1]; /* If opening a non-empty database, check the text encoding. For the ** main database, set sqlite3.enc to the encoding of the main database. ** For an attached db, it is an error if the encoding is not the same ** as sqlite3.enc. */ if( meta[BTREE_TEXT_ENCODING-1] ){ /* text encoding */ if( iDb==0 ){ u8 encoding; /* If opening the main database, set ENC(db). */ encoding = (u8)meta[BTREE_TEXT_ENCODING-1] & 3; if( encoding==0 ) encoding = SQLITE_UTF8; ENC(db) = encoding; db->pDfltColl = sqlite3FindCollSeq(db, SQLITE_UTF8, "BINARY", 0); }else{ /* If opening an attached database, the encoding much match ENC(db) */ if( meta[BTREE_TEXT_ENCODING-1]!=ENC(db) ){ sqlite3SetString(pzErrMsg, db, "attached databases must use the same" " text encoding as main database"); rc = SQLITE_ERROR; goto initone_error_out; } } }else{ DbSetProperty(db, iDb, DB_Empty); } pDb->pSchema->enc = ENC(db); if( pDb->pSchema->cache_size==0 ){ size = meta[BTREE_DEFAULT_CACHE_SIZE-1]; if( size==0 ){ size = SQLITE_DEFAULT_CACHE_SIZE; } if( size<0 ) size = -size; pDb->pSchema->cache_size = size; sqlite3BtreeSetCacheSize(pDb->pBt, pDb->pSchema->cache_size); } /* ** file_format==1 Version 3.0.0. ** file_format==2 Version 3.1.3. // ALTER TABLE ADD COLUMN ** file_format==3 Version 3.1.4. // ditto but with non-NULL defaults ** file_format==4 Version 3.3.0. // DESC indices. Boolean constants */ pDb->pSchema->file_format = (u8)meta[BTREE_FILE_FORMAT-1]; if( pDb->pSchema->file_format==0 ){ pDb->pSchema->file_format = 1; } if( pDb->pSchema->file_format>SQLITE_MAX_FILE_FORMAT ){ sqlite3SetString(pzErrMsg, db, "unsupported file format"); rc = SQLITE_ERROR; goto initone_error_out; } /* Ticket #2804: When we open a database in the newer file format, ** clear the legacy_file_format pragma flag so that a VACUUM will ** not downgrade the database and thus invalidate any descending ** indices that the user might have created. */ if( iDb==0 && meta[BTREE_FILE_FORMAT-1]>=4 ){ db->flags &= ~SQLITE_LegacyFileFmt; } /* Read the schema information out of the schema tables */ assert( db->init.busy ); { char *zSql; zSql = sqlite3MPrintf(db, "SELECT name, rootpage, sql FROM '%q'.%s", db->aDb[iDb].zName, zMasterName); (void)sqlite3SafetyOff(db); #ifndef SQLITE_OMIT_AUTHORIZATION { int (*xAuth)(void*,int,const char*,const char*,const char*,const char*); xAuth = db->xAuth; db->xAuth = 0; #endif rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0); #ifndef SQLITE_OMIT_AUTHORIZATION db->xAuth = xAuth; } #endif if( rc==SQLITE_OK ) rc = initData.rc; (void)sqlite3SafetyOn(db); sqlite3DbFree(db, zSql); #ifndef SQLITE_OMIT_ANALYZE if( rc==SQLITE_OK ){ sqlite3AnalysisLoad(db, iDb); } #endif } if( db->mallocFailed ){ rc = SQLITE_NOMEM; sqlite3ResetInternalSchema(db, 0); } if( rc==SQLITE_OK || (db->flags&SQLITE_RecoveryMode)){ /* Black magic: If the SQLITE_RecoveryMode flag is set, then consider ** the schema loaded, even if errors occurred. In this situation the ** current sqlite3_prepare() operation will fail, but the following one ** will attempt to compile the supplied statement against whatever subset ** of the schema was loaded before the error occurred. The primary ** purpose of this is to allow access to the sqlite_master table ** even when its contents have been corrupted. */ DbSetProperty(db, iDb, DB_SchemaLoaded); rc = SQLITE_OK; } /* Jump here for an error that occurs after successfully allocating ** curMain and calling sqlite3BtreeEnter(). For an error that occurs ** before that point, jump to error_out. */ initone_error_out: if( openedTransaction ){ sqlite3BtreeCommit(pDb->pBt); } sqlite3BtreeLeave(pDb->pBt); error_out: if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){ db->mallocFailed = 1; } return rc; }
/* ** Copy nPage pages from the source b-tree to the destination. */ int sqlite3_backup_step(sqlite3_backup *p, int nPage){ int rc; int destMode; /* Destination journal mode */ int pgszSrc = 0; /* Source page size */ int pgszDest = 0; /* Destination page size */ sqlite3_mutex_enter(p->pSrcDb->mutex); sqlite3BtreeEnter(p->pSrc); if( p->pDestDb ){ sqlite3_mutex_enter(p->pDestDb->mutex); } rc = p->rc; if( !isFatalError(rc) ){ Pager * const pSrcPager = sqlite3BtreePager(p->pSrc); /* Source pager */ Pager * const pDestPager = sqlite3BtreePager(p->pDest); /* Dest pager */ int ii; /* Iterator variable */ int nSrcPage = -1; /* Size of source db in pages */ int bCloseTrans = 0; /* True if src db requires unlocking */ /* If the source pager is currently in a write-transaction, return ** SQLITE_BUSY immediately. */ if( p->pDestDb && p->pSrc->pBt->inTransaction==TRANS_WRITE ){ rc = SQLITE_BUSY; }else{ rc = SQLITE_OK; } /* Lock the destination database, if it is not locked already. */ if( SQLITE_OK==rc && p->bDestLocked==0 && SQLITE_OK==(rc = sqlite3BtreeBeginTrans(p->pDest, 2)) ){ p->bDestLocked = 1; sqlite3BtreeGetMeta(p->pDest, BTREE_SCHEMA_VERSION, &p->iDestSchema); } /* If there is no open read-transaction on the source database, open ** one now. If a transaction is opened here, then it will be closed ** before this function exits. */ if( rc==SQLITE_OK && 0==sqlite3BtreeIsInReadTrans(p->pSrc) ){ rc = sqlite3BtreeBeginTrans(p->pSrc, 0); bCloseTrans = 1; } /* Do not allow backup if the destination database is in WAL mode ** and the page sizes are different between source and destination */ pgszSrc = sqlite3BtreeGetPageSize(p->pSrc); pgszDest = sqlite3BtreeGetPageSize(p->pDest); destMode = sqlite3PagerGetJournalMode(sqlite3BtreePager(p->pDest)); if( SQLITE_OK==rc && destMode==PAGER_JOURNALMODE_WAL && pgszSrc!=pgszDest ){ rc = SQLITE_READONLY; } /* Now that there is a read-lock on the source database, query the ** source pager for the number of pages in the database. */ nSrcPage = (int)sqlite3BtreeLastPage(p->pSrc); assert( nSrcPage>=0 ); for(ii=0; (nPage<0 || ii<nPage) && p->iNext<=(Pgno)nSrcPage && !rc; ii++){ const Pgno iSrcPg = p->iNext; /* Source page number */ if( iSrcPg!=PENDING_BYTE_PAGE(p->pSrc->pBt) ){ DbPage *pSrcPg; /* Source page object */ rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg); if( rc==SQLITE_OK ){ rc = backupOnePage(p, iSrcPg, sqlite3PagerGetData(pSrcPg)); sqlite3PagerUnref(pSrcPg); } } p->iNext++; } if( rc==SQLITE_OK ){ p->nPagecount = nSrcPage; p->nRemaining = nSrcPage+1-p->iNext; if( p->iNext>(Pgno)nSrcPage ){ rc = SQLITE_DONE; }else if( !p->isAttached ){ attachBackupObject(p); } } /* Update the schema version field in the destination database. This ** is to make sure that the schema-version really does change in ** the case where the source and destination databases have the ** same schema version. */ if( rc==SQLITE_DONE && (rc = sqlite3BtreeUpdateMeta(p->pDest,1,p->iDestSchema+1))==SQLITE_OK ){ int nDestTruncate; if( p->pDestDb ){ sqlite3ResetInternalSchema(p->pDestDb, 0); } /* Set nDestTruncate to the final number of pages in the destination ** database. The complication here is that the destination page ** size may be different to the source page size. ** ** If the source page size is smaller than the destination page size, ** round up. In this case the call to sqlite3OsTruncate() below will ** fix the size of the file. However it is important to call ** sqlite3PagerTruncateImage() here so that any pages in the ** destination file that lie beyond the nDestTruncate page mark are ** journalled by PagerCommitPhaseOne() before they are destroyed ** by the file truncation. */ assert( pgszSrc==sqlite3BtreeGetPageSize(p->pSrc) ); assert( pgszDest==sqlite3BtreeGetPageSize(p->pDest) ); if( pgszSrc<pgszDest ){ int ratio = pgszDest/pgszSrc; nDestTruncate = (nSrcPage+ratio-1)/ratio; if( nDestTruncate==(int)PENDING_BYTE_PAGE(p->pDest->pBt) ){ nDestTruncate--; } }else{ nDestTruncate = nSrcPage * (pgszSrc/pgszDest); } sqlite3PagerTruncateImage(pDestPager, nDestTruncate); if( pgszSrc<pgszDest ){ /* If the source page-size is smaller than the destination page-size, ** two extra things may need to happen: ** ** * The destination may need to be truncated, and ** ** * Data stored on the pages immediately following the ** pending-byte page in the source database may need to be ** copied into the destination database. */ const i64 iSize = (i64)pgszSrc * (i64)nSrcPage; sqlite3_file * const pFile = sqlite3PagerFile(pDestPager); assert( pFile ); assert( (i64)nDestTruncate*(i64)pgszDest >= iSize || ( nDestTruncate==(int)(PENDING_BYTE_PAGE(p->pDest->pBt)-1) && iSize>=PENDING_BYTE && iSize<=PENDING_BYTE+pgszDest )); if( SQLITE_OK==(rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 1)) && SQLITE_OK==(rc = backupTruncateFile(pFile, iSize)) && SQLITE_OK==(rc = sqlite3PagerSync(pDestPager)) ){ i64 iOff; i64 iEnd = MIN(PENDING_BYTE + pgszDest, iSize); for( iOff=PENDING_BYTE+pgszSrc; rc==SQLITE_OK && iOff<iEnd; iOff+=pgszSrc ){ PgHdr *pSrcPg = 0; const Pgno iSrcPg = (Pgno)((iOff/pgszSrc)+1); rc = sqlite3PagerGet(pSrcPager, iSrcPg, &pSrcPg); if( rc==SQLITE_OK ){ u8 *zData = sqlite3PagerGetData(pSrcPg); rc = sqlite3OsWrite(pFile, zData, pgszSrc, iOff); } sqlite3PagerUnref(pSrcPg); } } }else{ rc = sqlite3PagerCommitPhaseOne(pDestPager, 0, 0); } /* Finish committing the transaction to the destination database. */ if( SQLITE_OK==rc && SQLITE_OK==(rc = sqlite3BtreeCommitPhaseTwo(p->pDest)) ){ rc = SQLITE_DONE; } } /* If bCloseTrans is true, then this function opened a read transaction ** on the source database. Close the read transaction here. There is ** no need to check the return values of the btree methods here, as ** "committing" a read-only transaction cannot fail. */ if( bCloseTrans ){ TESTONLY( int rc2 ); TESTONLY( rc2 = ) sqlite3BtreeCommitPhaseOne(p->pSrc, 0); TESTONLY( rc2 |= ) sqlite3BtreeCommitPhaseTwo(p->pSrc); assert( rc2==SQLITE_OK ); } if( rc==SQLITE_IOERR_NOMEM ){ rc = SQLITE_NOMEM; } p->rc = rc; }