/* ** 2014 August 30 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** ** ** OVERVIEW ** ** The RBU extension requires that the RBU update be packaged as an ** SQLite database. The tables it expects to find are described in ** sqlite3rbu.h. Essentially, for each table xyz in the target database ** that the user wishes to write to, a corresponding data_xyz table is ** created in the RBU database and populated with one row for each row to ** update, insert or delete from the target table. ** ** The update proceeds in three stages: ** ** 1) The database is updated. The modified database pages are written ** to a *-oal file. A *-oal file is just like a *-wal file, except ** that it is named "-oal" instead of "-wal". ** Because regular SQLite clients do not look for file named ** "-oal", they go on using the original database in ** rollback mode while the *-oal file is being generated. ** ** During this stage RBU does not update the database by writing ** directly to the target tables. Instead it creates "imposter" ** tables using the SQLITE_TESTCTRL_IMPOSTER interface that it uses ** to update each b-tree individually. All updates required by each ** b-tree are completed before moving on to the next, and all ** updates are done in sorted key order. ** ** 2) The "-oal" file is moved to the equivalent "-wal" ** location using a call to rename(2). Before doing this the RBU ** module takes an EXCLUSIVE lock on the database file, ensuring ** that there are no other active readers. ** ** Once the EXCLUSIVE lock is released, any other database readers ** detect the new *-wal file and read the database in wal mode. At ** this point they see the new version of the database - including ** the updates made as part of the RBU update. ** ** 3) The new *-wal file is checkpointed. This proceeds in the same way ** as a regular database checkpoint, except that a single frame is ** checkpointed each time sqlite3rbu_step() is called. If the RBU ** handle is closed before the entire *-wal file is checkpointed, ** the checkpoint progress is saved in the RBU database and the ** checkpoint can be resumed by another RBU client at some point in ** the future. ** ** POTENTIAL PROBLEMS ** ** The rename() call might not be portable. And RBU is not currently ** syncing the directory after renaming the file. ** ** When state is saved, any commit to the *-oal file and the commit to ** the RBU update database are not atomic. So if the power fails at the ** wrong moment they might get out of sync. As the main database will be ** committed before the RBU update database this will likely either just ** pass unnoticed, or result in SQLITE_CONSTRAINT errors (due to UNIQUE ** constraint violations). ** ** If some client does modify the target database mid RBU update, or some ** other error occurs, the RBU extension will keep throwing errors. It's ** not really clear how to get out of this state. The system could just ** by delete the RBU update database and *-oal file and have the device ** download the update again and start over. ** ** At present, for an UPDATE, both the new.* and old.* records are ** collected in the rbu_xyz table. And for both UPDATEs and DELETEs all ** fields are collected. This means we're probably writing a lot more ** data to disk when saving the state of an ongoing update to the RBU ** update database than is strictly necessary. ** */ #include #include #include #include "sqlite3.h" #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_RBU) #include "sqlite3rbu.h" #if defined(_WIN32_WCE) #include "windows.h" #endif /* Maximum number of prepared UPDATE statements held by this module */ #define SQLITE_RBU_UPDATE_CACHESIZE 16 /* Delta checksums disabled by default. Compile with -DRBU_ENABLE_DELTA_CKSUM ** to enable checksum verification. */ #ifndef RBU_ENABLE_DELTA_CKSUM # define RBU_ENABLE_DELTA_CKSUM 0 #endif /* ** Swap two objects of type TYPE. */ #if !defined(SQLITE_AMALGAMATION) # define SWAP(TYPE,A,B) {TYPE t=A; A=B; B=t;} #endif /* ** The rbu_state table is used to save the state of a partially applied ** update so that it can be resumed later. The table consists of integer ** keys mapped to values as follows: ** ** RBU_STATE_STAGE: ** May be set to integer values 1, 2, 4 or 5. As follows: ** 1: the *-rbu file is currently under construction. ** 2: the *-rbu file has been constructed, but not yet moved ** to the *-wal path. ** 4: the checkpoint is underway. ** 5: the rbu update has been checkpointed. ** ** RBU_STATE_TBL: ** Only valid if STAGE==1. The target database name of the table ** currently being written. ** ** RBU_STATE_IDX: ** Only valid if STAGE==1. The target database name of the index ** currently being written, or NULL if the main table is currently being ** updated. ** ** RBU_STATE_ROW: ** Only valid if STAGE==1. Number of rows already processed for the current ** table/index. ** ** RBU_STATE_PROGRESS: ** Trbul number of sqlite3rbu_step() calls made so far as part of this ** rbu update. ** ** RBU_STATE_CKPT: ** Valid if STAGE==4. The 64-bit checksum associated with the wal-index ** header created by recovering the *-wal file. This is used to detect ** cases when another client appends frames to the *-wal file in the ** middle of an incremental checkpoint (an incremental checkpoint cannot ** be continued if this happens). ** ** RBU_STATE_COOKIE: ** Valid if STAGE==1. The current change-counter cookie value in the ** target db file. ** ** RBU_STATE_OALSZ: ** Valid if STAGE==1. The size in bytes of the *-oal file. ** ** RBU_STATE_DATATBL: ** Only valid if STAGE==1. The RBU database name of the table ** currently being read. */ #define RBU_STATE_STAGE 1 #define RBU_STATE_TBL 2 #define RBU_STATE_IDX 3 #define RBU_STATE_ROW 4 #define RBU_STATE_PROGRESS 5 #define RBU_STATE_CKPT 6 #define RBU_STATE_COOKIE 7 #define RBU_STATE_OALSZ 8 #define RBU_STATE_PHASEONESTEP 9 #define RBU_STATE_DATATBL 10 #define RBU_STAGE_OAL 1 #define RBU_STAGE_MOVE 2 #define RBU_STAGE_CAPTURE 3 #define RBU_STAGE_CKPT 4 #define RBU_STAGE_DONE 5 #define RBU_CREATE_STATE \ "CREATE TABLE IF NOT EXISTS %s.rbu_state(k INTEGER PRIMARY KEY, v)" typedef struct RbuFrame RbuFrame; typedef struct RbuObjIter RbuObjIter; typedef struct RbuState RbuState; typedef struct rbu_vfs rbu_vfs; typedef struct rbu_file rbu_file; typedef struct RbuUpdateStmt RbuUpdateStmt; #if !defined(SQLITE_AMALGAMATION) typedef unsigned int u32; typedef unsigned short u16; typedef unsigned char u8; typedef sqlite3_int64 i64; #endif /* ** These values must match the values defined in wal.c for the equivalent ** locks. These are not magic numbers as they are part of the SQLite file ** format. */ #define WAL_LOCK_WRITE 0 #define WAL_LOCK_CKPT 1 #define WAL_LOCK_READ0 3 #define SQLITE_FCNTL_RBUCNT 5149216 /* ** A structure to store values read from the rbu_state table in memory. */ struct RbuState { int eStage; char *zTbl; char *zDataTbl; char *zIdx; i64 iWalCksum; int nRow; i64 nProgress; u32 iCookie; i64 iOalSz; i64 nPhaseOneStep; }; struct RbuUpdateStmt { char *zMask; /* Copy of update mask used with pUpdate */ sqlite3_stmt *pUpdate; /* Last update statement (or NULL) */ RbuUpdateStmt *pNext; }; /* ** An iterator of this type is used to iterate through all objects in ** the target database that require updating. For each such table, the ** iterator visits, in order: ** ** * the table itself, ** * each index of the table (zero or more points to visit), and ** * a special "cleanup table" state. ** ** abIndexed: ** If the table has no indexes on it, abIndexed is set to NULL. Otherwise, ** it points to an array of flags nTblCol elements in size. The flag is ** set for each column that is either a part of the PK or a part of an ** index. Or clear otherwise. ** */ struct RbuObjIter { sqlite3_stmt *pTblIter; /* Iterate through tables */ sqlite3_stmt *pIdxIter; /* Index iterator */ int nTblCol; /* Size of azTblCol[] array */ char **azTblCol; /* Array of unquoted target column names */ char **azTblType; /* Array of target column types */ int *aiSrcOrder; /* src table col -> target table col */ u8 *abTblPk; /* Array of flags, set on target PK columns */ u8 *abNotNull; /* Array of flags, set on NOT NULL columns */ u8 *abIndexed; /* Array of flags, set on indexed & PK cols */ int eType; /* Table type - an RBU_PK_XXX value */ /* Output variables. zTbl==0 implies EOF. */ int bCleanup; /* True in "cleanup" state */ const char *zTbl; /* Name of target db table */ const char *zDataTbl; /* Name of rbu db table (or null) */ const char *zIdx; /* Name of target db index (or null) */ int iTnum; /* Root page of current object */ int iPkTnum; /* If eType==EXTERNAL, root of PK index */ int bUnique; /* Current index is unique */ int nIndex; /* Number of aux. indexes on table zTbl */ /* Statements created by rbuObjIterPrepareAll() */ int nCol; /* Number of columns in current object */ sqlite3_stmt *pSelect; /* Source data */ sqlite3_stmt *pInsert; /* Statement for INSERT operations */ sqlite3_stmt *pDelete; /* Statement for DELETE ops */ sqlite3_stmt *pTmpInsert; /* Insert into rbu_tmp_$zDataTbl */ /* Last UPDATE used (for PK b-tree updates only), or NULL. */ RbuUpdateStmt *pRbuUpdate; }; /* ** Values for RbuObjIter.eType ** ** 0: Table does not exist (error) ** 1: Table has an implicit rowid. ** 2: Table has an explicit IPK column. ** 3: Table has an external PK index. ** 4: Table is WITHOUT ROWID. ** 5: Table is a virtual table. */ #define RBU_PK_NOTABLE 0 #define RBU_PK_NONE 1 #define RBU_PK_IPK 2 #define RBU_PK_EXTERNAL 3 #define RBU_PK_WITHOUT_ROWID 4 #define RBU_PK_VTAB 5 /* ** Within the RBU_STAGE_OAL stage, each call to sqlite3rbu_step() performs ** one of the following operations. */ #define RBU_INSERT 1 /* Insert on a main table b-tree */ #define RBU_DELETE 2 /* Delete a row from a main table b-tree */ #define RBU_REPLACE 3 /* Delete and then insert a row */ #define RBU_IDX_DELETE 4 /* Delete a row from an aux. index b-tree */ #define RBU_IDX_INSERT 5 /* Insert on an aux. index b-tree */ #define RBU_UPDATE 6 /* Update a row in a main table b-tree */ /* ** A single step of an incremental checkpoint - frame iWalFrame of the wal ** file should be copied to page iDbPage of the database file. */ struct RbuFrame { u32 iDbPage; u32 iWalFrame; }; /* ** RBU handle. ** ** nPhaseOneStep: ** If the RBU database contains an rbu_count table, this value is set to ** a running estimate of the number of b-tree operations required to ** finish populating the *-oal file. This allows the sqlite3_bp_progress() ** API to calculate the permyriadage progress of populating the *-oal file ** using the formula: ** ** permyriadage = (10000 * nProgress) / nPhaseOneStep ** ** nPhaseOneStep is initialized to the sum of: ** ** nRow * (nIndex + 1) ** ** for all source tables in the RBU database, where nRow is the number ** of rows in the source table and nIndex the number of indexes on the ** corresponding target database table. ** ** This estimate is accurate if the RBU update consists entirely of ** INSERT operations. However, it is inaccurate if: ** ** * the RBU update contains any UPDATE operations. If the PK specified ** for an UPDATE operation does not exist in the target table, then ** no b-tree operations are required on index b-trees. Or if the ** specified PK does exist, then (nIndex*2) such operations are ** required (one delete and one insert on each index b-tree). ** ** * the RBU update contains any DELETE operations for which the specified ** PK does not exist. In this case no operations are required on index ** b-trees. ** ** * the RBU update contains REPLACE operations. These are similar to ** UPDATE operations. ** ** nPhaseOneStep is updated to account for the conditions above during the ** first pass of each source table. The updated nPhaseOneStep value is ** stored in the rbu_state table if the RBU update is suspended. */ struct sqlite3rbu { int eStage; /* Value of RBU_STATE_STAGE field */ sqlite3 *dbMain; /* target database handle */ sqlite3 *dbRbu; /* rbu database handle */ char *zTarget; /* Path to target db */ char *zRbu; /* Path to rbu db */ char *zState; /* Path to state db (or NULL if zRbu) */ char zStateDb[5]; /* Db name for state ("stat" or "main") */ int rc; /* Value returned by last rbu_step() call */ char *zErrmsg; /* Error message if rc!=SQLITE_OK */ int nStep; /* Rows processed for current object */ int nProgress; /* Rows processed for all objects */ RbuObjIter objiter; /* Iterator for skipping through tbl/idx */ const char *zVfsName; /* Name of automatically created rbu vfs */ rbu_file *pTargetFd; /* File handle open on target db */ int nPagePerSector; /* Pages per sector for pTargetFd */ i64 iOalSz; i64 nPhaseOneStep; /* The following state variables are used as part of the incremental ** checkpoint stage (eStage==RBU_STAGE_CKPT). See comments surrounding ** function rbuSetupCheckpoint() for details. */ u32 iMaxFrame; /* Largest iWalFrame value in aFrame[] */ u32 mLock; int nFrame; /* Entries in aFrame[] array */ int nFrameAlloc; /* Allocated size of aFrame[] array */ RbuFrame *aFrame; int pgsz; u8 *aBuf; i64 iWalCksum; i64 szTemp; /* Current size of all temp files in use */ i64 szTempLimit; /* Total size limit for temp files */ /* Used in RBU vacuum mode only */ int nRbu; /* Number of RBU VFS in the stack */ rbu_file *pRbuFd; /* Fd for main db of dbRbu */ }; /* ** An rbu VFS is implemented using an instance of this structure. ** ** Variable pRbu is only non-NULL for automatically created RBU VFS objects. ** It is NULL for RBU VFS objects created explicitly using ** sqlite3rbu_create_vfs(). It is used to track the total amount of temp ** space used by the RBU handle. */ struct rbu_vfs { sqlite3_vfs base; /* rbu VFS shim methods */ sqlite3_vfs *pRealVfs; /* Underlying VFS */ sqlite3_mutex *mutex; /* Mutex to protect pMain */ sqlite3rbu *pRbu; /* Owner RBU object */ rbu_file *pMain; /* List of main db files */ rbu_file *pMainRbu; /* List of main db files with pRbu!=0 */ }; /* ** Each file opened by an rbu VFS is represented by an instance of ** the following structure. ** ** If this is a temporary file (pRbu!=0 && flags&DELETE_ON_CLOSE), variable ** "sz" is set to the current size of the database file. */ struct rbu_file { sqlite3_file base; /* sqlite3_file methods */ sqlite3_file *pReal; /* Underlying file handle */ rbu_vfs *pRbuVfs; /* Pointer to the rbu_vfs object */ sqlite3rbu *pRbu; /* Pointer to rbu object (rbu target only) */ i64 sz; /* Size of file in bytes (temp only) */ int openFlags; /* Flags this file was opened with */ u32 iCookie; /* Cookie value for main db files */ u8 iWriteVer; /* "write-version" value for main db files */ u8 bNolock; /* True to fail EXCLUSIVE locks */ int nShm; /* Number of entries in apShm[] array */ char **apShm; /* Array of mmap'd *-shm regions */ char *zDel; /* Delete this when closing file */ const char *zWal; /* Wal filename for this main db file */ rbu_file *pWalFd; /* Wal file descriptor for this main db */ rbu_file *pMainNext; /* Next MAIN_DB file */ rbu_file *pMainRbuNext; /* Next MAIN_DB file with pRbu!=0 */ }; /* ** True for an RBU vacuum handle, or false otherwise. */ #define rbuIsVacuum(p) ((p)->zTarget==0) /************************************************************************* ** The following three functions, found below: ** ** rbuDeltaGetInt() ** rbuDeltaChecksum() ** rbuDeltaApply() ** ** are lifted from the fossil source code (http://fossil-scm.org). They ** are used to implement the scalar SQL function rbu_fossil_delta(). */ /* ** Read bytes from *pz and convert them into a positive integer. When ** finished, leave *pz pointing to the first character past the end of ** the integer. The *pLen parameter holds the length of the string ** in *pz and is decremented once for each character in the integer. */ static unsigned int rbuDeltaGetInt(const char **pz, int *pLen){ static const signed char zValue[] = { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, -1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, -1, -1, -1, -1, 36, -1, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, -1, -1, -1, 63, -1, }; unsigned int v = 0; int c; unsigned char *z = (unsigned char*)*pz; unsigned char *zStart = z; while( (c = zValue[0x7f&*(z++)])>=0 ){ v = (v<<6) + c; } z--; *pLen -= z - zStart; *pz = (char*)z; return v; } #if RBU_ENABLE_DELTA_CKSUM /* ** Compute a 32-bit checksum on the N-byte buffer. Return the result. */ static unsigned int rbuDeltaChecksum(const char *zIn, size_t N){ const unsigned char *z = (const unsigned char *)zIn; unsigned sum0 = 0; unsigned sum1 = 0; unsigned sum2 = 0; unsigned sum3 = 0; while(N >= 16){ sum0 += ((unsigned)z[0] + z[4] + z[8] + z[12]); sum1 += ((unsigned)z[1] + z[5] + z[9] + z[13]); sum2 += ((unsigned)z[2] + z[6] + z[10]+ z[14]); sum3 += ((unsigned)z[3] + z[7] + z[11]+ z[15]); z += 16; N -= 16; } while(N >= 4){ sum0 += z[0]; sum1 += z[1]; sum2 += z[2]; sum3 += z[3]; z += 4; N -= 4; } sum3 += (sum2 << 8) + (sum1 << 16) + (sum0 << 24); switch(N){ case 3: sum3 += (z[2] << 8); case 2: sum3 += (z[1] << 16); case 1: sum3 += (z[0] << 24); default: ; } return sum3; } #endif /* ** Apply a delta. ** ** The output buffer should be big enough to hold the whole output ** file and a NUL terminator at the end. The delta_output_size() ** routine will determine this size for you. ** ** The delta string should be null-terminated. But the delta string ** may contain embedded NUL characters (if the input and output are ** binary files) so we also have to pass in the length of the delta in ** the lenDelta parameter. ** ** This function returns the size of the output file in bytes (excluding ** the final NUL terminator character). Except, if the delta string is ** malformed or intended for use with a source file other than zSrc, ** then this routine returns -1. ** ** Refer to the delta_create() documentation above for a description ** of the delta file format. */ static int rbuDeltaApply( const char *zSrc, /* The source or pattern file */ int lenSrc, /* Length of the source file */ const char *zDelta, /* Delta to apply to the pattern */ int lenDelta, /* Length of the delta */ char *zOut /* Write the output into this preallocated buffer */ ){ unsigned int limit; unsigned int total = 0; #if RBU_ENABLE_DELTA_CKSUM char *zOrigOut = zOut; #endif limit = rbuDeltaGetInt(&zDelta, &lenDelta); if( *zDelta!='\n' ){ /* ERROR: size integer not terminated by "\n" */ return -1; } zDelta++; lenDelta--; while( *zDelta && lenDelta>0 ){ unsigned int cnt, ofst; cnt = rbuDeltaGetInt(&zDelta, &lenDelta); switch( zDelta[0] ){ case '@': { zDelta++; lenDelta--; ofst = rbuDeltaGetInt(&zDelta, &lenDelta); if( lenDelta>0 && zDelta[0]!=',' ){ /* ERROR: copy command not terminated by ',' */ return -1; } zDelta++; lenDelta--; total += cnt; if( total>limit ){ /* ERROR: copy exceeds output file size */ return -1; } if( (int)(ofst+cnt) > lenSrc ){ /* ERROR: copy extends past end of input */ return -1; } memcpy(zOut, &zSrc[ofst], cnt); zOut += cnt; break; } case ':': { zDelta++; lenDelta--; total += cnt; if( total>limit ){ /* ERROR: insert command gives an output larger than predicted */ return -1; } if( (int)cnt>lenDelta ){ /* ERROR: insert count exceeds size of delta */ return -1; } memcpy(zOut, zDelta, cnt); zOut += cnt; zDelta += cnt; lenDelta -= cnt; break; } case ';': { zDelta++; lenDelta--; zOut[0] = 0; #if RBU_ENABLE_DELTA_CKSUM if( cnt!=rbuDeltaChecksum(zOrigOut, total) ){ /* ERROR: bad checksum */ return -1; } #endif if( total!=limit ){ /* ERROR: generated size does not match predicted size */ return -1; } return total; } default: { /* ERROR: unknown delta operator */ return -1; } } } /* ERROR: unterminated delta */ return -1; } static int rbuDeltaOutputSize(const char *zDelta, int lenDelta){ int size; size = rbuDeltaGetInt(&zDelta, &lenDelta); if( *zDelta!='\n' ){ /* ERROR: size integer not terminated by "\n" */ return -1; } return size; } /* ** End of code taken from fossil. *************************************************************************/ /* ** Implementation of SQL scalar function rbu_fossil_delta(). ** ** This function applies a fossil delta patch to a blob. Exactly two ** arguments must be passed to this function. The first is the blob to ** patch and the second the patch to apply. If no error occurs, this ** function returns the patched blob. */ static void rbuFossilDeltaFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ const char *aDelta; int nDelta; const char *aOrig; int nOrig; int nOut; int nOut2; char *aOut; assert( argc==2 ); nOrig = sqlite3_value_bytes(argv[0]); aOrig = (const char*)sqlite3_value_blob(argv[0]); nDelta = sqlite3_value_bytes(argv[1]); aDelta = (const char*)sqlite3_value_blob(argv[1]); /* Figure out the size of the output */ nOut = rbuDeltaOutputSize(aDelta, nDelta); if( nOut<0 ){ sqlite3_result_error(context, "corrupt fossil delta", -1); return; } aOut = sqlite3_malloc(nOut+1); if( aOut==0 ){ sqlite3_result_error_nomem(context); }else{ nOut2 = rbuDeltaApply(aOrig, nOrig, aDelta, nDelta, aOut); if( nOut2!=nOut ){ sqlite3_result_error(context, "corrupt fossil delta", -1); }else{ sqlite3_result_blob(context, aOut, nOut, sqlite3_free); } } } /* ** Prepare the SQL statement in buffer zSql against database handle db. ** If successful, set *ppStmt to point to the new statement and return ** SQLITE_OK. ** ** Otherwise, if an error does occur, set *ppStmt to NULL and return ** an SQLite error code. Additionally, set output variable *pzErrmsg to ** point to a buffer containing an error message. It is the responsibility ** of the caller to (eventually) free this buffer using sqlite3_free(). */ static int prepareAndCollectError( sqlite3 *db, sqlite3_stmt **ppStmt, char **pzErrmsg, const char *zSql ){ int rc = sqlite3_prepare_v2(db, zSql, -1, ppStmt, 0); if( rc!=SQLITE_OK ){ *pzErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(db)); *ppStmt = 0; } return rc; } /* ** Reset the SQL statement passed as the first argument. Return a copy ** of the value returned by sqlite3_reset(). ** ** If an error has occurred, then set *pzErrmsg to point to a buffer ** containing an error message. It is the responsibility of the caller ** to eventually free this buffer using sqlite3_free(). */ static int resetAndCollectError(sqlite3_stmt *pStmt, char **pzErrmsg){ int rc = sqlite3_reset(pStmt); if( rc!=SQLITE_OK ){ *pzErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(sqlite3_db_handle(pStmt))); } return rc; } /* ** Unless it is NULL, argument zSql points to a buffer allocated using ** sqlite3_malloc containing an SQL statement. This function prepares the SQL ** statement against database db and frees the buffer. If statement ** compilation is successful, *ppStmt is set to point to the new statement ** handle and SQLITE_OK is returned. ** ** Otherwise, if an error occurs, *ppStmt is set to NULL and an error code ** returned. In this case, *pzErrmsg may also be set to point to an error ** message. It is the responsibility of the caller to free this error message ** buffer using sqlite3_free(). ** ** If argument zSql is NULL, this function assumes that an OOM has occurred. ** In this case SQLITE_NOMEM is returned and *ppStmt set to NULL. */ static int prepareFreeAndCollectError( sqlite3 *db, sqlite3_stmt **ppStmt, char **pzErrmsg, char *zSql ){ int rc; assert( *pzErrmsg==0 ); if( zSql==0 ){ rc = SQLITE_NOMEM; *ppStmt = 0; }else{ rc = prepareAndCollectError(db, ppStmt, pzErrmsg, zSql); sqlite3_free(zSql); } return rc; } /* ** Free the RbuObjIter.azTblCol[] and RbuObjIter.abTblPk[] arrays allocated ** by an earlier call to rbuObjIterCacheTableInfo(). */ static void rbuObjIterFreeCols(RbuObjIter *pIter){ int i; for(i=0; inTblCol; i++){ sqlite3_free(pIter->azTblCol[i]); sqlite3_free(pIter->azTblType[i]); } sqlite3_free(pIter->azTblCol); pIter->azTblCol = 0; pIter->azTblType = 0; pIter->aiSrcOrder = 0; pIter->abTblPk = 0; pIter->abNotNull = 0; pIter->nTblCol = 0; pIter->eType = 0; /* Invalid value */ } /* ** Finalize all statements and free all allocations that are specific to ** the current object (table/index pair). */ static void rbuObjIterClearStatements(RbuObjIter *pIter){ RbuUpdateStmt *pUp; sqlite3_finalize(pIter->pSelect); sqlite3_finalize(pIter->pInsert); sqlite3_finalize(pIter->pDelete); sqlite3_finalize(pIter->pTmpInsert); pUp = pIter->pRbuUpdate; while( pUp ){ RbuUpdateStmt *pTmp = pUp->pNext; sqlite3_finalize(pUp->pUpdate); sqlite3_free(pUp); pUp = pTmp; } pIter->pSelect = 0; pIter->pInsert = 0; pIter->pDelete = 0; pIter->pRbuUpdate = 0; pIter->pTmpInsert = 0; pIter->nCol = 0; } /* ** Clean up any resources allocated as part of the iterator object passed ** as the only argument. */ static void rbuObjIterFinalize(RbuObjIter *pIter){ rbuObjIterClearStatements(pIter); sqlite3_finalize(pIter->pTblIter); sqlite3_finalize(pIter->pIdxIter); rbuObjIterFreeCols(pIter); memset(pIter, 0, sizeof(RbuObjIter)); } /* ** Advance the iterator to the next position. ** ** If no error occurs, SQLITE_OK is returned and the iterator is left ** pointing to the next entry. Otherwise, an error code and message is ** left in the RBU handle passed as the first argument. A copy of the ** error code is returned. */ static int rbuObjIterNext(sqlite3rbu *p, RbuObjIter *pIter){ int rc = p->rc; if( rc==SQLITE_OK ){ /* Free any SQLite statements used while processing the previous object */ rbuObjIterClearStatements(pIter); if( pIter->zIdx==0 ){ rc = sqlite3_exec(p->dbMain, "DROP TRIGGER IF EXISTS temp.rbu_insert_tr;" "DROP TRIGGER IF EXISTS temp.rbu_update1_tr;" "DROP TRIGGER IF EXISTS temp.rbu_update2_tr;" "DROP TRIGGER IF EXISTS temp.rbu_delete_tr;" , 0, 0, &p->zErrmsg ); } if( rc==SQLITE_OK ){ if( pIter->bCleanup ){ rbuObjIterFreeCols(pIter); pIter->bCleanup = 0; rc = sqlite3_step(pIter->pTblIter); if( rc!=SQLITE_ROW ){ rc = resetAndCollectError(pIter->pTblIter, &p->zErrmsg); pIter->zTbl = 0; }else{ pIter->zTbl = (const char*)sqlite3_column_text(pIter->pTblIter, 0); pIter->zDataTbl = (const char*)sqlite3_column_text(pIter->pTblIter,1); rc = (pIter->zDataTbl && pIter->zTbl) ? SQLITE_OK : SQLITE_NOMEM; } }else{ if( pIter->zIdx==0 ){ sqlite3_stmt *pIdx = pIter->pIdxIter; rc = sqlite3_bind_text(pIdx, 1, pIter->zTbl, -1, SQLITE_STATIC); } if( rc==SQLITE_OK ){ rc = sqlite3_step(pIter->pIdxIter); if( rc!=SQLITE_ROW ){ rc = resetAndCollectError(pIter->pIdxIter, &p->zErrmsg); pIter->bCleanup = 1; pIter->zIdx = 0; }else{ pIter->zIdx = (const char*)sqlite3_column_text(pIter->pIdxIter, 0); pIter->iTnum = sqlite3_column_int(pIter->pIdxIter, 1); pIter->bUnique = sqlite3_column_int(pIter->pIdxIter, 2); rc = pIter->zIdx ? SQLITE_OK : SQLITE_NOMEM; } } } } } if( rc!=SQLITE_OK ){ rbuObjIterFinalize(pIter); p->rc = rc; } return rc; } /* ** The implementation of the rbu_target_name() SQL function. This function ** accepts one or two arguments. The first argument is the name of a table - ** the name of a table in the RBU database. The second, if it is present, is 1 ** for a view or 0 for a table. ** ** For a non-vacuum RBU handle, if the table name matches the pattern: ** ** data[0-9]_ ** ** where is any sequence of 1 or more characters, is returned. ** Otherwise, if the only argument does not match the above pattern, an SQL ** NULL is returned. ** ** "data_t1" -> "t1" ** "data0123_t2" -> "t2" ** "dataAB_t3" -> NULL ** ** For an rbu vacuum handle, a copy of the first argument is returned if ** the second argument is either missing or 0 (not a view). */ static void rbuTargetNameFunc( sqlite3_context *pCtx, int argc, sqlite3_value **argv ){ sqlite3rbu *p = sqlite3_user_data(pCtx); const char *zIn; assert( argc==1 || argc==2 ); zIn = (const char*)sqlite3_value_text(argv[0]); if( zIn ){ if( rbuIsVacuum(p) ){ if( argc==1 || 0==sqlite3_value_int(argv[1]) ){ sqlite3_result_text(pCtx, zIn, -1, SQLITE_STATIC); } }else{ if( strlen(zIn)>4 && memcmp("data", zIn, 4)==0 ){ int i; for(i=4; zIn[i]>='0' && zIn[i]<='9'; i++); if( zIn[i]=='_' && zIn[i+1] ){ sqlite3_result_text(pCtx, &zIn[i+1], -1, SQLITE_STATIC); } } } } } /* ** Initialize the iterator structure passed as the second argument. ** ** If no error occurs, SQLITE_OK is returned and the iterator is left ** pointing to the first entry. Otherwise, an error code and message is ** left in the RBU handle passed as the first argument. A copy of the ** error code is returned. */ static int rbuObjIterFirst(sqlite3rbu *p, RbuObjIter *pIter){ int rc; memset(pIter, 0, sizeof(RbuObjIter)); rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pTblIter, &p->zErrmsg, sqlite3_mprintf( "SELECT rbu_target_name(name, type='view') AS target, name " "FROM sqlite_master " "WHERE type IN ('table', 'view') AND target IS NOT NULL " " %s " "ORDER BY name" , rbuIsVacuum(p) ? "AND rootpage!=0 AND rootpage IS NOT NULL" : "")); if( rc==SQLITE_OK ){ rc = prepareAndCollectError(p->dbMain, &pIter->pIdxIter, &p->zErrmsg, "SELECT name, rootpage, sql IS NULL OR substr(8, 6)=='UNIQUE' " " FROM main.sqlite_master " " WHERE type='index' AND tbl_name = ?" ); } pIter->bCleanup = 1; p->rc = rc; return rbuObjIterNext(p, pIter); } /* ** This is a wrapper around "sqlite3_mprintf(zFmt, ...)". If an OOM occurs, ** an error code is stored in the RBU handle passed as the first argument. ** ** If an error has already occurred (p->rc is already set to something other ** than SQLITE_OK), then this function returns NULL without modifying the ** stored error code. In this case it still calls sqlite3_free() on any ** printf() parameters associated with %z conversions. */ static char *rbuMPrintf(sqlite3rbu *p, const char *zFmt, ...){ char *zSql = 0; va_list ap; va_start(ap, zFmt); zSql = sqlite3_vmprintf(zFmt, ap); if( p->rc==SQLITE_OK ){ if( zSql==0 ) p->rc = SQLITE_NOMEM; }else{ sqlite3_free(zSql); zSql = 0; } va_end(ap); return zSql; } /* ** Argument zFmt is a sqlite3_mprintf() style format string. The trailing ** arguments are the usual subsitution values. This function performs ** the printf() style substitutions and executes the result as an SQL ** statement on the RBU handles database. ** ** If an error occurs, an error code and error message is stored in the ** RBU handle. If an error has already occurred when this function is ** called, it is a no-op. */ static int rbuMPrintfExec(sqlite3rbu *p, sqlite3 *db, const char *zFmt, ...){ va_list ap; char *zSql; va_start(ap, zFmt); zSql = sqlite3_vmprintf(zFmt, ap); if( p->rc==SQLITE_OK ){ if( zSql==0 ){ p->rc = SQLITE_NOMEM; }else{ p->rc = sqlite3_exec(db, zSql, 0, 0, &p->zErrmsg); } } sqlite3_free(zSql); va_end(ap); return p->rc; } /* ** Attempt to allocate and return a pointer to a zeroed block of nByte ** bytes. ** ** If an error (i.e. an OOM condition) occurs, return NULL and leave an ** error code in the rbu handle passed as the first argument. Or, if an ** error has already occurred when this function is called, return NULL ** immediately without attempting the allocation or modifying the stored ** error code. */ static void *rbuMalloc(sqlite3rbu *p, int nByte){ void *pRet = 0; if( p->rc==SQLITE_OK ){ assert( nByte>0 ); pRet = sqlite3_malloc64(nByte); if( pRet==0 ){ p->rc = SQLITE_NOMEM; }else{ memset(pRet, 0, nByte); } } return pRet; } /* ** Allocate and zero the pIter->azTblCol[] and abTblPk[] arrays so that ** there is room for at least nCol elements. If an OOM occurs, store an ** error code in the RBU handle passed as the first argument. */ static void rbuAllocateIterArrays(sqlite3rbu *p, RbuObjIter *pIter, int nCol){ int nByte = (2*sizeof(char*) + sizeof(int) + 3*sizeof(u8)) * nCol; char **azNew; azNew = (char**)rbuMalloc(p, nByte); if( azNew ){ pIter->azTblCol = azNew; pIter->azTblType = &azNew[nCol]; pIter->aiSrcOrder = (int*)&pIter->azTblType[nCol]; pIter->abTblPk = (u8*)&pIter->aiSrcOrder[nCol]; pIter->abNotNull = (u8*)&pIter->abTblPk[nCol]; pIter->abIndexed = (u8*)&pIter->abNotNull[nCol]; } } /* ** The first argument must be a nul-terminated string. This function ** returns a copy of the string in memory obtained from sqlite3_malloc(). ** It is the responsibility of the caller to eventually free this memory ** using sqlite3_free(). ** ** If an OOM condition is encountered when attempting to allocate memory, ** output variable (*pRc) is set to SQLITE_NOMEM before returning. Otherwise, ** if the allocation succeeds, (*pRc) is left unchanged. */ static char *rbuStrndup(const char *zStr, int *pRc){ char *zRet = 0; assert( *pRc==SQLITE_OK ); if( zStr ){ size_t nCopy = strlen(zStr) + 1; zRet = (char*)sqlite3_malloc64(nCopy); if( zRet ){ memcpy(zRet, zStr, nCopy); }else{ *pRc = SQLITE_NOMEM; } } return zRet; } /* ** Finalize the statement passed as the second argument. ** ** If the sqlite3_finalize() call indicates that an error occurs, and the ** rbu handle error code is not already set, set the error code and error ** message accordingly. */ static void rbuFinalize(sqlite3rbu *p, sqlite3_stmt *pStmt){ sqlite3 *db = sqlite3_db_handle(pStmt); int rc = sqlite3_finalize(pStmt); if( p->rc==SQLITE_OK && rc!=SQLITE_OK ){ p->rc = rc; p->zErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(db)); } } /* Determine the type of a table. ** ** peType is of type (int*), a pointer to an output parameter of type ** (int). This call sets the output parameter as follows, depending ** on the type of the table specified by parameters dbName and zTbl. ** ** RBU_PK_NOTABLE: No such table. ** RBU_PK_NONE: Table has an implicit rowid. ** RBU_PK_IPK: Table has an explicit IPK column. ** RBU_PK_EXTERNAL: Table has an external PK index. ** RBU_PK_WITHOUT_ROWID: Table is WITHOUT ROWID. ** RBU_PK_VTAB: Table is a virtual table. ** ** Argument *piPk is also of type (int*), and also points to an output ** parameter. Unless the table has an external primary key index ** (i.e. unless *peType is set to 3), then *piPk is set to zero. Or, ** if the table does have an external primary key index, then *piPk ** is set to the root page number of the primary key index before ** returning. ** ** ALGORITHM: ** ** if( no entry exists in sqlite_master ){ ** return RBU_PK_NOTABLE ** }else if( sql for the entry starts with "CREATE VIRTUAL" ){ ** return RBU_PK_VTAB ** }else if( "PRAGMA index_list()" for the table contains a "pk" index ){ ** if( the index that is the pk exists in sqlite_master ){ ** *piPK = rootpage of that index. ** return RBU_PK_EXTERNAL ** }else{ ** return RBU_PK_WITHOUT_ROWID ** } ** }else if( "PRAGMA table_info()" lists one or more "pk" columns ){ ** return RBU_PK_IPK ** }else{ ** return RBU_PK_NONE ** } */ static void rbuTableType( sqlite3rbu *p, const char *zTab, int *peType, int *piTnum, int *piPk ){ /* ** 0) SELECT count(*) FROM sqlite_master where name=%Q AND IsVirtual(%Q) ** 1) PRAGMA index_list = ? ** 2) SELECT count(*) FROM sqlite_master where name=%Q ** 3) PRAGMA table_info = ? */ sqlite3_stmt *aStmt[4] = {0, 0, 0, 0}; *peType = RBU_PK_NOTABLE; *piPk = 0; assert( p->rc==SQLITE_OK ); p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[0], &p->zErrmsg, sqlite3_mprintf( "SELECT (sql LIKE 'create virtual%%'), rootpage" " FROM sqlite_master" " WHERE name=%Q", zTab )); if( p->rc!=SQLITE_OK || sqlite3_step(aStmt[0])!=SQLITE_ROW ){ /* Either an error, or no such table. */ goto rbuTableType_end; } if( sqlite3_column_int(aStmt[0], 0) ){ *peType = RBU_PK_VTAB; /* virtual table */ goto rbuTableType_end; } *piTnum = sqlite3_column_int(aStmt[0], 1); p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[1], &p->zErrmsg, sqlite3_mprintf("PRAGMA index_list=%Q",zTab) ); if( p->rc ) goto rbuTableType_end; while( sqlite3_step(aStmt[1])==SQLITE_ROW ){ const u8 *zOrig = sqlite3_column_text(aStmt[1], 3); const u8 *zIdx = sqlite3_column_text(aStmt[1], 1); if( zOrig && zIdx && zOrig[0]=='p' ){ p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[2], &p->zErrmsg, sqlite3_mprintf( "SELECT rootpage FROM sqlite_master WHERE name = %Q", zIdx )); if( p->rc==SQLITE_OK ){ if( sqlite3_step(aStmt[2])==SQLITE_ROW ){ *piPk = sqlite3_column_int(aStmt[2], 0); *peType = RBU_PK_EXTERNAL; }else{ *peType = RBU_PK_WITHOUT_ROWID; } } goto rbuTableType_end; } } p->rc = prepareFreeAndCollectError(p->dbMain, &aStmt[3], &p->zErrmsg, sqlite3_mprintf("PRAGMA table_info=%Q",zTab) ); if( p->rc==SQLITE_OK ){ while( sqlite3_step(aStmt[3])==SQLITE_ROW ){ if( sqlite3_column_int(aStmt[3],5)>0 ){ *peType = RBU_PK_IPK; /* explicit IPK column */ goto rbuTableType_end; } } *peType = RBU_PK_NONE; } rbuTableType_end: { unsigned int i; for(i=0; iabIndexed[] array. */ static void rbuObjIterCacheIndexedCols(sqlite3rbu *p, RbuObjIter *pIter){ sqlite3_stmt *pList = 0; int bIndex = 0; if( p->rc==SQLITE_OK ){ memcpy(pIter->abIndexed, pIter->abTblPk, sizeof(u8)*pIter->nTblCol); p->rc = prepareFreeAndCollectError(p->dbMain, &pList, &p->zErrmsg, sqlite3_mprintf("PRAGMA main.index_list = %Q", pIter->zTbl) ); } pIter->nIndex = 0; while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pList) ){ const char *zIdx = (const char*)sqlite3_column_text(pList, 1); sqlite3_stmt *pXInfo = 0; if( zIdx==0 ) break; p->rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg, sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", zIdx) ); while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){ int iCid = sqlite3_column_int(pXInfo, 1); if( iCid>=0 ) pIter->abIndexed[iCid] = 1; } rbuFinalize(p, pXInfo); bIndex = 1; pIter->nIndex++; } if( pIter->eType==RBU_PK_WITHOUT_ROWID ){ /* "PRAGMA index_list" includes the main PK b-tree */ pIter->nIndex--; } rbuFinalize(p, pList); if( bIndex==0 ) pIter->abIndexed = 0; } /* ** If they are not already populated, populate the pIter->azTblCol[], ** pIter->abTblPk[], pIter->nTblCol and pIter->bRowid variables according to ** the table (not index) that the iterator currently points to. ** ** Return SQLITE_OK if successful, or an SQLite error code otherwise. If ** an error does occur, an error code and error message are also left in ** the RBU handle. */ static int rbuObjIterCacheTableInfo(sqlite3rbu *p, RbuObjIter *pIter){ if( pIter->azTblCol==0 ){ sqlite3_stmt *pStmt = 0; int nCol = 0; int i; /* for() loop iterator variable */ int bRbuRowid = 0; /* If input table has column "rbu_rowid" */ int iOrder = 0; int iTnum = 0; /* Figure out the type of table this step will deal with. */ assert( pIter->eType==0 ); rbuTableType(p, pIter->zTbl, &pIter->eType, &iTnum, &pIter->iPkTnum); if( p->rc==SQLITE_OK && pIter->eType==RBU_PK_NOTABLE ){ p->rc = SQLITE_ERROR; p->zErrmsg = sqlite3_mprintf("no such table: %s", pIter->zTbl); } if( p->rc ) return p->rc; if( pIter->zIdx==0 ) pIter->iTnum = iTnum; assert( pIter->eType==RBU_PK_NONE || pIter->eType==RBU_PK_IPK || pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_WITHOUT_ROWID || pIter->eType==RBU_PK_VTAB ); /* Populate the azTblCol[] and nTblCol variables based on the columns ** of the input table. Ignore any input table columns that begin with ** "rbu_". */ p->rc = prepareFreeAndCollectError(p->dbRbu, &pStmt, &p->zErrmsg, sqlite3_mprintf("SELECT * FROM '%q'", pIter->zDataTbl) ); if( p->rc==SQLITE_OK ){ nCol = sqlite3_column_count(pStmt); rbuAllocateIterArrays(p, pIter, nCol); } for(i=0; p->rc==SQLITE_OK && irc); pIter->aiSrcOrder[pIter->nTblCol] = pIter->nTblCol; pIter->azTblCol[pIter->nTblCol++] = zCopy; } else if( 0==sqlite3_stricmp("rbu_rowid", zName) ){ bRbuRowid = 1; } } sqlite3_finalize(pStmt); pStmt = 0; if( p->rc==SQLITE_OK && rbuIsVacuum(p)==0 && bRbuRowid!=(pIter->eType==RBU_PK_VTAB || pIter->eType==RBU_PK_NONE) ){ p->rc = SQLITE_ERROR; p->zErrmsg = sqlite3_mprintf( "table %q %s rbu_rowid column", pIter->zDataTbl, (bRbuRowid ? "may not have" : "requires") ); } /* Check that all non-HIDDEN columns in the destination table are also ** present in the input table. Populate the abTblPk[], azTblType[] and ** aiTblOrder[] arrays at the same time. */ if( p->rc==SQLITE_OK ){ p->rc = prepareFreeAndCollectError(p->dbMain, &pStmt, &p->zErrmsg, sqlite3_mprintf("PRAGMA table_info(%Q)", pIter->zTbl) ); } while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){ const char *zName = (const char*)sqlite3_column_text(pStmt, 1); if( zName==0 ) break; /* An OOM - finalize() below returns S_NOMEM */ for(i=iOrder; inTblCol; i++){ if( 0==strcmp(zName, pIter->azTblCol[i]) ) break; } if( i==pIter->nTblCol ){ p->rc = SQLITE_ERROR; p->zErrmsg = sqlite3_mprintf("column missing from %q: %s", pIter->zDataTbl, zName ); }else{ int iPk = sqlite3_column_int(pStmt, 5); int bNotNull = sqlite3_column_int(pStmt, 3); const char *zType = (const char*)sqlite3_column_text(pStmt, 2); if( i!=iOrder ){ SWAP(int, pIter->aiSrcOrder[i], pIter->aiSrcOrder[iOrder]); SWAP(char*, pIter->azTblCol[i], pIter->azTblCol[iOrder]); } pIter->azTblType[iOrder] = rbuStrndup(zType, &p->rc); pIter->abTblPk[iOrder] = (iPk!=0); pIter->abNotNull[iOrder] = (u8)bNotNull || (iPk!=0); iOrder++; } } rbuFinalize(p, pStmt); rbuObjIterCacheIndexedCols(p, pIter); assert( pIter->eType!=RBU_PK_VTAB || pIter->abIndexed==0 ); assert( pIter->eType!=RBU_PK_VTAB || pIter->nIndex==0 ); } return p->rc; } /* ** This function constructs and returns a pointer to a nul-terminated ** string containing some SQL clause or list based on one or more of the ** column names currently stored in the pIter->azTblCol[] array. */ static char *rbuObjIterGetCollist( sqlite3rbu *p, /* RBU object */ RbuObjIter *pIter /* Object iterator for column names */ ){ char *zList = 0; const char *zSep = ""; int i; for(i=0; inTblCol; i++){ const char *z = pIter->azTblCol[i]; zList = rbuMPrintf(p, "%z%s\"%w\"", zList, zSep, z); zSep = ", "; } return zList; } /* ** This function is used to create a SELECT list (the list of SQL ** expressions that follows a SELECT keyword) for a SELECT statement ** used to read from an data_xxx or rbu_tmp_xxx table while updating the ** index object currently indicated by the iterator object passed as the ** second argument. A "PRAGMA index_xinfo = " statement is used ** to obtain the required information. ** ** If the index is of the following form: ** ** CREATE INDEX i1 ON t1(c, b COLLATE nocase); ** ** and "t1" is a table with an explicit INTEGER PRIMARY KEY column ** "ipk", the returned string is: ** ** "`c` COLLATE 'BINARY', `b` COLLATE 'NOCASE', `ipk` COLLATE 'BINARY'" ** ** As well as the returned string, three other malloc'd strings are ** returned via output parameters. As follows: ** ** pzImposterCols: ... ** pzImposterPk: ... ** pzWhere: ... */ static char *rbuObjIterGetIndexCols( sqlite3rbu *p, /* RBU object */ RbuObjIter *pIter, /* Object iterator for column names */ char **pzImposterCols, /* OUT: Columns for imposter table */ char **pzImposterPk, /* OUT: Imposter PK clause */ char **pzWhere, /* OUT: WHERE clause */ int *pnBind /* OUT: Trbul number of columns */ ){ int rc = p->rc; /* Error code */ int rc2; /* sqlite3_finalize() return code */ char *zRet = 0; /* String to return */ char *zImpCols = 0; /* String to return via *pzImposterCols */ char *zImpPK = 0; /* String to return via *pzImposterPK */ char *zWhere = 0; /* String to return via *pzWhere */ int nBind = 0; /* Value to return via *pnBind */ const char *zCom = ""; /* Set to ", " later on */ const char *zAnd = ""; /* Set to " AND " later on */ sqlite3_stmt *pXInfo = 0; /* PRAGMA index_xinfo = ? */ if( rc==SQLITE_OK ){ assert( p->zErrmsg==0 ); rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg, sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", pIter->zIdx) ); } while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){ int iCid = sqlite3_column_int(pXInfo, 1); int bDesc = sqlite3_column_int(pXInfo, 3); const char *zCollate = (const char*)sqlite3_column_text(pXInfo, 4); const char *zCol; const char *zType; if( iCid<0 ){ /* An integer primary key. If the table has an explicit IPK, use ** its name. Otherwise, use "rbu_rowid". */ if( pIter->eType==RBU_PK_IPK ){ int i; for(i=0; pIter->abTblPk[i]==0; i++); assert( inTblCol ); zCol = pIter->azTblCol[i]; }else if( rbuIsVacuum(p) ){ zCol = "_rowid_"; }else{ zCol = "rbu_rowid"; } zType = "INTEGER"; }else{ zCol = pIter->azTblCol[iCid]; zType = pIter->azTblType[iCid]; } zRet = sqlite3_mprintf("%z%s\"%w\" COLLATE %Q", zRet, zCom, zCol, zCollate); if( pIter->bUnique==0 || sqlite3_column_int(pXInfo, 5) ){ const char *zOrder = (bDesc ? " DESC" : ""); zImpPK = sqlite3_mprintf("%z%s\"rbu_imp_%d%w\"%s", zImpPK, zCom, nBind, zCol, zOrder ); } zImpCols = sqlite3_mprintf("%z%s\"rbu_imp_%d%w\" %s COLLATE %Q", zImpCols, zCom, nBind, zCol, zType, zCollate ); zWhere = sqlite3_mprintf( "%z%s\"rbu_imp_%d%w\" IS ?", zWhere, zAnd, nBind, zCol ); if( zRet==0 || zImpPK==0 || zImpCols==0 || zWhere==0 ) rc = SQLITE_NOMEM; zCom = ", "; zAnd = " AND "; nBind++; } rc2 = sqlite3_finalize(pXInfo); if( rc==SQLITE_OK ) rc = rc2; if( rc!=SQLITE_OK ){ sqlite3_free(zRet); sqlite3_free(zImpCols); sqlite3_free(zImpPK); sqlite3_free(zWhere); zRet = 0; zImpCols = 0; zImpPK = 0; zWhere = 0; p->rc = rc; } *pzImposterCols = zImpCols; *pzImposterPk = zImpPK; *pzWhere = zWhere; *pnBind = nBind; return zRet; } /* ** Assuming the current table columns are "a", "b" and "c", and the zObj ** paramter is passed "old", return a string of the form: ** ** "old.a, old.b, old.b" ** ** With the column names escaped. ** ** For tables with implicit rowids - RBU_PK_EXTERNAL and RBU_PK_NONE, append ** the text ", old._rowid_" to the returned value. */ static char *rbuObjIterGetOldlist( sqlite3rbu *p, RbuObjIter *pIter, const char *zObj ){ char *zList = 0; if( p->rc==SQLITE_OK && pIter->abIndexed ){ const char *zS = ""; int i; for(i=0; inTblCol; i++){ if( pIter->abIndexed[i] ){ const char *zCol = pIter->azTblCol[i]; zList = sqlite3_mprintf("%z%s%s.\"%w\"", zList, zS, zObj, zCol); }else{ zList = sqlite3_mprintf("%z%sNULL", zList, zS); } zS = ", "; if( zList==0 ){ p->rc = SQLITE_NOMEM; break; } } /* For a table with implicit rowids, append "old._rowid_" to the list. */ if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){ zList = rbuMPrintf(p, "%z, %s._rowid_", zList, zObj); } } return zList; } /* ** Return an expression that can be used in a WHERE clause to match the ** primary key of the current table. For example, if the table is: ** ** CREATE TABLE t1(a, b, c, PRIMARY KEY(b, c)); ** ** Return the string: ** ** "b = ?1 AND c = ?2" */ static char *rbuObjIterGetWhere( sqlite3rbu *p, RbuObjIter *pIter ){ char *zList = 0; if( pIter->eType==RBU_PK_VTAB || pIter->eType==RBU_PK_NONE ){ zList = rbuMPrintf(p, "_rowid_ = ?%d", pIter->nTblCol+1); }else if( pIter->eType==RBU_PK_EXTERNAL ){ const char *zSep = ""; int i; for(i=0; inTblCol; i++){ if( pIter->abTblPk[i] ){ zList = rbuMPrintf(p, "%z%sc%d=?%d", zList, zSep, i, i+1); zSep = " AND "; } } zList = rbuMPrintf(p, "_rowid_ = (SELECT id FROM rbu_imposter2 WHERE %z)", zList ); }else{ const char *zSep = ""; int i; for(i=0; inTblCol; i++){ if( pIter->abTblPk[i] ){ const char *zCol = pIter->azTblCol[i]; zList = rbuMPrintf(p, "%z%s\"%w\"=?%d", zList, zSep, zCol, i+1); zSep = " AND "; } } } return zList; } /* ** The SELECT statement iterating through the keys for the current object ** (p->objiter.pSelect) currently points to a valid row. However, there ** is something wrong with the rbu_control value in the rbu_control value ** stored in the (p->nCol+1)'th column. Set the error code and error message ** of the RBU handle to something reflecting this. */ static void rbuBadControlError(sqlite3rbu *p){ p->rc = SQLITE_ERROR; p->zErrmsg = sqlite3_mprintf("invalid rbu_control value"); } /* ** Return a nul-terminated string containing the comma separated list of ** assignments that should be included following the "SET" keyword of ** an UPDATE statement used to update the table object that the iterator ** passed as the second argument currently points to if the rbu_control ** column of the data_xxx table entry is set to zMask. ** ** The memory for the returned string is obtained from sqlite3_malloc(). ** It is the responsibility of the caller to eventually free it using ** sqlite3_free(). ** ** If an OOM error is encountered when allocating space for the new ** string, an error code is left in the rbu handle passed as the first ** argument and NULL is returned. Or, if an error has already occurred ** when this function is called, NULL is returned immediately, without ** attempting the allocation or modifying the stored error code. */ static char *rbuObjIterGetSetlist( sqlite3rbu *p, RbuObjIter *pIter, const char *zMask ){ char *zList = 0; if( p->rc==SQLITE_OK ){ int i; if( (int)strlen(zMask)!=pIter->nTblCol ){ rbuBadControlError(p); }else{ const char *zSep = ""; for(i=0; inTblCol; i++){ char c = zMask[pIter->aiSrcOrder[i]]; if( c=='x' ){ zList = rbuMPrintf(p, "%z%s\"%w\"=?%d", zList, zSep, pIter->azTblCol[i], i+1 ); zSep = ", "; } else if( c=='d' ){ zList = rbuMPrintf(p, "%z%s\"%w\"=rbu_delta(\"%w\", ?%d)", zList, zSep, pIter->azTblCol[i], pIter->azTblCol[i], i+1 ); zSep = ", "; } else if( c=='f' ){ zList = rbuMPrintf(p, "%z%s\"%w\"=rbu_fossil_delta(\"%w\", ?%d)", zList, zSep, pIter->azTblCol[i], pIter->azTblCol[i], i+1 ); zSep = ", "; } } } } return zList; } /* ** Return a nul-terminated string consisting of nByte comma separated ** "?" expressions. For example, if nByte is 3, return a pointer to ** a buffer containing the string "?,?,?". ** ** The memory for the returned string is obtained from sqlite3_malloc(). ** It is the responsibility of the caller to eventually free it using ** sqlite3_free(). ** ** If an OOM error is encountered when allocating space for the new ** string, an error code is left in the rbu handle passed as the first ** argument and NULL is returned. Or, if an error has already occurred ** when this function is called, NULL is returned immediately, without ** attempting the allocation or modifying the stored error code. */ static char *rbuObjIterGetBindlist(sqlite3rbu *p, int nBind){ char *zRet = 0; int nByte = nBind*2 + 1; zRet = (char*)rbuMalloc(p, nByte); if( zRet ){ int i; for(i=0; izIdx==0 ); if( p->rc==SQLITE_OK ){ const char *zSep = "PRIMARY KEY("; sqlite3_stmt *pXList = 0; /* PRAGMA index_list = (pIter->zTbl) */ sqlite3_stmt *pXInfo = 0; /* PRAGMA index_xinfo = */ p->rc = prepareFreeAndCollectError(p->dbMain, &pXList, &p->zErrmsg, sqlite3_mprintf("PRAGMA main.index_list = %Q", pIter->zTbl) ); while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXList) ){ const char *zOrig = (const char*)sqlite3_column_text(pXList,3); if( zOrig && strcmp(zOrig, "pk")==0 ){ const char *zIdx = (const char*)sqlite3_column_text(pXList,1); if( zIdx ){ p->rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg, sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", zIdx) ); } break; } } rbuFinalize(p, pXList); while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){ if( sqlite3_column_int(pXInfo, 5) ){ /* int iCid = sqlite3_column_int(pXInfo, 0); */ const char *zCol = (const char*)sqlite3_column_text(pXInfo, 2); const char *zDesc = sqlite3_column_int(pXInfo, 3) ? " DESC" : ""; z = rbuMPrintf(p, "%z%s\"%w\"%s", z, zSep, zCol, zDesc); zSep = ", "; } } z = rbuMPrintf(p, "%z)", z); rbuFinalize(p, pXInfo); } return z; } /* ** This function creates the second imposter table used when writing to ** a table b-tree where the table has an external primary key. If the ** iterator passed as the second argument does not currently point to ** a table (not index) with an external primary key, this function is a ** no-op. ** ** Assuming the iterator does point to a table with an external PK, this ** function creates a WITHOUT ROWID imposter table named "rbu_imposter2" ** used to access that PK index. For example, if the target table is ** declared as follows: ** ** CREATE TABLE t1(a, b TEXT, c REAL, PRIMARY KEY(b, c)); ** ** then the imposter table schema is: ** ** CREATE TABLE rbu_imposter2(c1 TEXT, c2 REAL, id INTEGER) WITHOUT ROWID; ** */ static void rbuCreateImposterTable2(sqlite3rbu *p, RbuObjIter *pIter){ if( p->rc==SQLITE_OK && pIter->eType==RBU_PK_EXTERNAL ){ int tnum = pIter->iPkTnum; /* Root page of PK index */ sqlite3_stmt *pQuery = 0; /* SELECT name ... WHERE rootpage = $tnum */ const char *zIdx = 0; /* Name of PK index */ sqlite3_stmt *pXInfo = 0; /* PRAGMA main.index_xinfo = $zIdx */ const char *zComma = ""; char *zCols = 0; /* Used to build up list of table cols */ char *zPk = 0; /* Used to build up table PK declaration */ /* Figure out the name of the primary key index for the current table. ** This is needed for the argument to "PRAGMA index_xinfo". Set ** zIdx to point to a nul-terminated string containing this name. */ p->rc = prepareAndCollectError(p->dbMain, &pQuery, &p->zErrmsg, "SELECT name FROM sqlite_master WHERE rootpage = ?" ); if( p->rc==SQLITE_OK ){ sqlite3_bind_int(pQuery, 1, tnum); if( SQLITE_ROW==sqlite3_step(pQuery) ){ zIdx = (const char*)sqlite3_column_text(pQuery, 0); } } if( zIdx ){ p->rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg, sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", zIdx) ); } rbuFinalize(p, pQuery); while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){ int bKey = sqlite3_column_int(pXInfo, 5); if( bKey ){ int iCid = sqlite3_column_int(pXInfo, 1); int bDesc = sqlite3_column_int(pXInfo, 3); const char *zCollate = (const char*)sqlite3_column_text(pXInfo, 4); zCols = rbuMPrintf(p, "%z%sc%d %s COLLATE %Q", zCols, zComma, iCid, pIter->azTblType[iCid], zCollate ); zPk = rbuMPrintf(p, "%z%sc%d%s", zPk, zComma, iCid, bDesc?" DESC":""); zComma = ", "; } } zCols = rbuMPrintf(p, "%z, id INTEGER", zCols); rbuFinalize(p, pXInfo); sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 1, tnum); rbuMPrintfExec(p, p->dbMain, "CREATE TABLE rbu_imposter2(%z, PRIMARY KEY(%z)) WITHOUT ROWID", zCols, zPk ); sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 0); } } /* ** If an error has already occurred when this function is called, it ** immediately returns zero (without doing any work). Or, if an error ** occurs during the execution of this function, it sets the error code ** in the sqlite3rbu object indicated by the first argument and returns ** zero. ** ** The iterator passed as the second argument is guaranteed to point to ** a table (not an index) when this function is called. This function ** attempts to create any imposter table required to write to the main ** table b-tree of the table before returning. Non-zero is returned if ** an imposter table are created, or zero otherwise. ** ** An imposter table is required in all cases except RBU_PK_VTAB. Only ** virtual tables are written to directly. The imposter table has the ** same schema as the actual target table (less any UNIQUE constraints). ** More precisely, the "same schema" means the same columns, types, ** collation sequences. For tables that do not have an external PRIMARY ** KEY, it also means the same PRIMARY KEY declaration. */ static void rbuCreateImposterTable(sqlite3rbu *p, RbuObjIter *pIter){ if( p->rc==SQLITE_OK && pIter->eType!=RBU_PK_VTAB ){ int tnum = pIter->iTnum; const char *zComma = ""; char *zSql = 0; int iCol; sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 1); for(iCol=0; p->rc==SQLITE_OK && iColnTblCol; iCol++){ const char *zPk = ""; const char *zCol = pIter->azTblCol[iCol]; const char *zColl = 0; p->rc = sqlite3_table_column_metadata( p->dbMain, "main", pIter->zTbl, zCol, 0, &zColl, 0, 0, 0 ); if( pIter->eType==RBU_PK_IPK && pIter->abTblPk[iCol] ){ /* If the target table column is an "INTEGER PRIMARY KEY", add ** "PRIMARY KEY" to the imposter table column declaration. */ zPk = "PRIMARY KEY "; } zSql = rbuMPrintf(p, "%z%s\"%w\" %s %sCOLLATE %Q%s", zSql, zComma, zCol, pIter->azTblType[iCol], zPk, zColl, (pIter->abNotNull[iCol] ? " NOT NULL" : "") ); zComma = ", "; } if( pIter->eType==RBU_PK_WITHOUT_ROWID ){ char *zPk = rbuWithoutRowidPK(p, pIter); if( zPk ){ zSql = rbuMPrintf(p, "%z, %z", zSql, zPk); } } sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 1, tnum); rbuMPrintfExec(p, p->dbMain, "CREATE TABLE \"rbu_imp_%w\"(%z)%s", pIter->zTbl, zSql, (pIter->eType==RBU_PK_WITHOUT_ROWID ? " WITHOUT ROWID" : "") ); sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 0); } } /* ** Prepare a statement used to insert rows into the "rbu_tmp_xxx" table. ** Specifically a statement of the form: ** ** INSERT INTO rbu_tmp_xxx VALUES(?, ?, ? ...); ** ** The number of bound variables is equal to the number of columns in ** the target table, plus one (for the rbu_control column), plus one more ** (for the rbu_rowid column) if the target table is an implicit IPK or ** virtual table. */ static void rbuObjIterPrepareTmpInsert( sqlite3rbu *p, RbuObjIter *pIter, const char *zCollist, const char *zRbuRowid ){ int bRbuRowid = (pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE); char *zBind = rbuObjIterGetBindlist(p, pIter->nTblCol + 1 + bRbuRowid); if( zBind ){ assert( pIter->pTmpInsert==0 ); p->rc = prepareFreeAndCollectError( p->dbRbu, &pIter->pTmpInsert, &p->zErrmsg, sqlite3_mprintf( "INSERT INTO %s.'rbu_tmp_%q'(rbu_control,%s%s) VALUES(%z)", p->zStateDb, pIter->zDataTbl, zCollist, zRbuRowid, zBind )); } } static void rbuTmpInsertFunc( sqlite3_context *pCtx, int nVal, sqlite3_value **apVal ){ sqlite3rbu *p = sqlite3_user_data(pCtx); int rc = SQLITE_OK; int i; assert( sqlite3_value_int(apVal[0])!=0 || p->objiter.eType==RBU_PK_EXTERNAL || p->objiter.eType==RBU_PK_NONE ); if( sqlite3_value_int(apVal[0])!=0 ){ p->nPhaseOneStep += p->objiter.nIndex; } for(i=0; rc==SQLITE_OK && iobjiter.pTmpInsert, i+1, apVal[i]); } if( rc==SQLITE_OK ){ sqlite3_step(p->objiter.pTmpInsert); rc = sqlite3_reset(p->objiter.pTmpInsert); } if( rc!=SQLITE_OK ){ sqlite3_result_error_code(pCtx, rc); } } /* ** Ensure that the SQLite statement handles required to update the ** target database object currently indicated by the iterator passed ** as the second argument are available. */ static int rbuObjIterPrepareAll( sqlite3rbu *p, RbuObjIter *pIter, int nOffset /* Add "LIMIT -1 OFFSET $nOffset" to SELECT */ ){ assert( pIter->bCleanup==0 ); if( pIter->pSelect==0 && rbuObjIterCacheTableInfo(p, pIter)==SQLITE_OK ){ const int tnum = pIter->iTnum; char *zCollist = 0; /* List of indexed columns */ char **pz = &p->zErrmsg; const char *zIdx = pIter->zIdx; char *zLimit = 0; if( nOffset ){ zLimit = sqlite3_mprintf(" LIMIT -1 OFFSET %d", nOffset); if( !zLimit ) p->rc = SQLITE_NOMEM; } if( zIdx ){ const char *zTbl = pIter->zTbl; char *zImposterCols = 0; /* Columns for imposter table */ char *zImposterPK = 0; /* Primary key declaration for imposter */ char *zWhere = 0; /* WHERE clause on PK columns */ char *zBind = 0; int nBind = 0; assert( pIter->eType!=RBU_PK_VTAB ); zCollist = rbuObjIterGetIndexCols( p, pIter, &zImposterCols, &zImposterPK, &zWhere, &nBind ); zBind = rbuObjIterGetBindlist(p, nBind); /* Create the imposter table used to write to this index. */ sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 1); sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 1,tnum); rbuMPrintfExec(p, p->dbMain, "CREATE TABLE \"rbu_imp_%w\"( %s, PRIMARY KEY( %s ) ) WITHOUT ROWID", zTbl, zImposterCols, zImposterPK ); sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, p->dbMain, "main", 0, 0); /* Create the statement to insert index entries */ pIter->nCol = nBind; if( p->rc==SQLITE_OK ){ p->rc = prepareFreeAndCollectError( p->dbMain, &pIter->pInsert, &p->zErrmsg, sqlite3_mprintf("INSERT INTO \"rbu_imp_%w\" VALUES(%s)", zTbl, zBind) ); } /* And to delete index entries */ if( rbuIsVacuum(p)==0 && p->rc==SQLITE_OK ){ p->rc = prepareFreeAndCollectError( p->dbMain, &pIter->pDelete, &p->zErrmsg, sqlite3_mprintf("DELETE FROM \"rbu_imp_%w\" WHERE %s", zTbl, zWhere) ); } /* Create the SELECT statement to read keys in sorted order */ if( p->rc==SQLITE_OK ){ char *zSql; if( rbuIsVacuum(p) ){ zSql = sqlite3_mprintf( "SELECT %s, 0 AS rbu_control FROM '%q' ORDER BY %s%s", zCollist, pIter->zDataTbl, zCollist, zLimit ); }else if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){ zSql = sqlite3_mprintf( "SELECT %s, rbu_control FROM %s.'rbu_tmp_%q' ORDER BY %s%s", zCollist, p->zStateDb, pIter->zDataTbl, zCollist, zLimit ); }else{ zSql = sqlite3_mprintf( "SELECT %s, rbu_control FROM %s.'rbu_tmp_%q' " "UNION ALL " "SELECT %s, rbu_control FROM '%q' " "WHERE typeof(rbu_control)='integer' AND rbu_control!=1 " "ORDER BY %s%s", zCollist, p->zStateDb, pIter->zDataTbl, zCollist, pIter->zDataTbl, zCollist, zLimit ); } p->rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pSelect, pz, zSql); } sqlite3_free(zImposterCols); sqlite3_free(zImposterPK); sqlite3_free(zWhere); sqlite3_free(zBind); }else{ int bRbuRowid = (pIter->eType==RBU_PK_VTAB) ||(pIter->eType==RBU_PK_NONE) ||(pIter->eType==RBU_PK_EXTERNAL && rbuIsVacuum(p)); const char *zTbl = pIter->zTbl; /* Table this step applies to */ const char *zWrite; /* Imposter table name */ char *zBindings = rbuObjIterGetBindlist(p, pIter->nTblCol + bRbuRowid); char *zWhere = rbuObjIterGetWhere(p, pIter); char *zOldlist = rbuObjIterGetOldlist(p, pIter, "old"); char *zNewlist = rbuObjIterGetOldlist(p, pIter, "new"); zCollist = rbuObjIterGetCollist(p, pIter); pIter->nCol = pIter->nTblCol; /* Create the imposter table or tables (if required). */ rbuCreateImposterTable(p, pIter); rbuCreateImposterTable2(p, pIter); zWrite = (pIter->eType==RBU_PK_VTAB ? "" : "rbu_imp_"); /* Create the INSERT statement to write to the target PK b-tree */ if( p->rc==SQLITE_OK ){ p->rc = prepareFreeAndCollectError(p->dbMain, &pIter->pInsert, pz, sqlite3_mprintf( "INSERT INTO \"%s%w\"(%s%s) VALUES(%s)", zWrite, zTbl, zCollist, (bRbuRowid ? ", _rowid_" : ""), zBindings ) ); } /* Create the DELETE statement to write to the target PK b-tree. ** Because it only performs INSERT operations, this is not required for ** an rbu vacuum handle. */ if( rbuIsVacuum(p)==0 && p->rc==SQLITE_OK ){ p->rc = prepareFreeAndCollectError(p->dbMain, &pIter->pDelete, pz, sqlite3_mprintf( "DELETE FROM \"%s%w\" WHERE %s", zWrite, zTbl, zWhere ) ); } if( rbuIsVacuum(p)==0 && pIter->abIndexed ){ const char *zRbuRowid = ""; if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){ zRbuRowid = ", rbu_rowid"; } /* Create the rbu_tmp_xxx table and the triggers to populate it. */ rbuMPrintfExec(p, p->dbRbu, "CREATE TABLE IF NOT EXISTS %s.'rbu_tmp_%q' AS " "SELECT *%s FROM '%q' WHERE 0;" , p->zStateDb, pIter->zDataTbl , (pIter->eType==RBU_PK_EXTERNAL ? ", 0 AS rbu_rowid" : "") , pIter->zDataTbl ); rbuMPrintfExec(p, p->dbMain, "CREATE TEMP TRIGGER rbu_delete_tr BEFORE DELETE ON \"%s%w\" " "BEGIN " " SELECT rbu_tmp_insert(3, %s);" "END;" "CREATE TEMP TRIGGER rbu_update1_tr BEFORE UPDATE ON \"%s%w\" " "BEGIN " " SELECT rbu_tmp_insert(3, %s);" "END;" "CREATE TEMP TRIGGER rbu_update2_tr AFTER UPDATE ON \"%s%w\" " "BEGIN " " SELECT rbu_tmp_insert(4, %s);" "END;", zWrite, zTbl, zOldlist, zWrite, zTbl, zOldlist, zWrite, zTbl, zNewlist ); if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){ rbuMPrintfExec(p, p->dbMain, "CREATE TEMP TRIGGER rbu_insert_tr AFTER INSERT ON \"%s%w\" " "BEGIN " " SELECT rbu_tmp_insert(0, %s);" "END;", zWrite, zTbl, zNewlist ); } rbuObjIterPrepareTmpInsert(p, pIter, zCollist, zRbuRowid); } /* Create the SELECT statement to read keys from data_xxx */ if( p->rc==SQLITE_OK ){ const char *zRbuRowid = ""; if( bRbuRowid ){ zRbuRowid = rbuIsVacuum(p) ? ",_rowid_ " : ",rbu_rowid"; } p->rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pSelect, pz, sqlite3_mprintf( "SELECT %s,%s rbu_control%s FROM '%q'%s", zCollist, (rbuIsVacuum(p) ? "0 AS " : ""), zRbuRowid, pIter->zDataTbl, zLimit ) ); } sqlite3_free(zWhere); sqlite3_free(zOldlist); sqlite3_free(zNewlist); sqlite3_free(zBindings); } sqlite3_free(zCollist); sqlite3_free(zLimit); } return p->rc; } /* ** Set output variable *ppStmt to point to an UPDATE statement that may ** be used to update the imposter table for the main table b-tree of the ** table object that pIter currently points to, assuming that the ** rbu_control column of the data_xyz table contains zMask. ** ** If the zMask string does not specify any columns to update, then this ** is not an error. Output variable *ppStmt is set to NULL in this case. */ static int rbuGetUpdateStmt( sqlite3rbu *p, /* RBU handle */ RbuObjIter *pIter, /* Object iterator */ const char *zMask, /* rbu_control value ('x.x.') */ sqlite3_stmt **ppStmt /* OUT: UPDATE statement handle */ ){ RbuUpdateStmt **pp; RbuUpdateStmt *pUp = 0; int nUp = 0; /* In case an error occurs */ *ppStmt = 0; /* Search for an existing statement. If one is found, shift it to the front ** of the LRU queue and return immediately. Otherwise, leave nUp pointing ** to the number of statements currently in the cache and pUp to the ** last object in the list. */ for(pp=&pIter->pRbuUpdate; *pp; pp=&((*pp)->pNext)){ pUp = *pp; if( strcmp(pUp->zMask, zMask)==0 ){ *pp = pUp->pNext; pUp->pNext = pIter->pRbuUpdate; pIter->pRbuUpdate = pUp; *ppStmt = pUp->pUpdate; return SQLITE_OK; } nUp++; } assert( pUp==0 || pUp->pNext==0 ); if( nUp>=SQLITE_RBU_UPDATE_CACHESIZE ){ for(pp=&pIter->pRbuUpdate; *pp!=pUp; pp=&((*pp)->pNext)); *pp = 0; sqlite3_finalize(pUp->pUpdate); pUp->pUpdate = 0; }else{ pUp = (RbuUpdateStmt*)rbuMalloc(p, sizeof(RbuUpdateStmt)+pIter->nTblCol+1); } if( pUp ){ char *zWhere = rbuObjIterGetWhere(p, pIter); char *zSet = rbuObjIterGetSetlist(p, pIter, zMask); char *zUpdate = 0; pUp->zMask = (char*)&pUp[1]; memcpy(pUp->zMask, zMask, pIter->nTblCol); pUp->pNext = pIter->pRbuUpdate; pIter->pRbuUpdate = pUp; if( zSet ){ const char *zPrefix = ""; if( pIter->eType!=RBU_PK_VTAB ) zPrefix = "rbu_imp_"; zUpdate = sqlite3_mprintf("UPDATE \"%s%w\" SET %s WHERE %s", zPrefix, pIter->zTbl, zSet, zWhere ); p->rc = prepareFreeAndCollectError( p->dbMain, &pUp->pUpdate, &p->zErrmsg, zUpdate ); *ppStmt = pUp->pUpdate; } sqlite3_free(zWhere); sqlite3_free(zSet); } return p->rc; } static sqlite3 *rbuOpenDbhandle( sqlite3rbu *p, const char *zName, int bUseVfs ){ sqlite3 *db = 0; if( p->rc==SQLITE_OK ){ const int flags = SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|SQLITE_OPEN_URI; p->rc = sqlite3_open_v2(zName, &db, flags, bUseVfs ? p->zVfsName : 0); if( p->rc ){ p->zErrmsg = sqlite3_mprintf("%s", sqlite3_errmsg(db)); sqlite3_close(db); db = 0; } } return db; } /* ** Free an RbuState object allocated by rbuLoadState(). */ static void rbuFreeState(RbuState *p){ if( p ){ sqlite3_free(p->zTbl); sqlite3_free(p->zDataTbl); sqlite3_free(p->zIdx); sqlite3_free(p); } } /* ** Allocate an RbuState object and load the contents of the rbu_state ** table into it. Return a pointer to the new object. It is the ** responsibility of the caller to eventually free the object using ** sqlite3_free(). ** ** If an error occurs, leave an error code and message in the rbu handle ** and return NULL. */ static RbuState *rbuLoadState(sqlite3rbu *p){ RbuState *pRet = 0; sqlite3_stmt *pStmt = 0; int rc; int rc2; pRet = (RbuState*)rbuMalloc(p, sizeof(RbuState)); if( pRet==0 ) return 0; rc = prepareFreeAndCollectError(p->dbRbu, &pStmt, &p->zErrmsg, sqlite3_mprintf("SELECT k, v FROM %s.rbu_state", p->zStateDb) ); while( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){ switch( sqlite3_column_int(pStmt, 0) ){ case RBU_STATE_STAGE: pRet->eStage = sqlite3_column_int(pStmt, 1); if( pRet->eStage!=RBU_STAGE_OAL && pRet->eStage!=RBU_STAGE_MOVE && pRet->eStage!=RBU_STAGE_CKPT ){ p->rc = SQLITE_CORRUPT; } break; case RBU_STATE_TBL: pRet->zTbl = rbuStrndup((char*)sqlite3_column_text(pStmt, 1), &rc); break; case RBU_STATE_IDX: pRet->zIdx = rbuStrndup((char*)sqlite3_column_text(pStmt, 1), &rc); break; case RBU_STATE_ROW: pRet->nRow = sqlite3_column_int(pStmt, 1); break; case RBU_STATE_PROGRESS: pRet->nProgress = sqlite3_column_int64(pStmt, 1); break; case RBU_STATE_CKPT: pRet->iWalCksum = sqlite3_column_int64(pStmt, 1); break; case RBU_STATE_COOKIE: pRet->iCookie = (u32)sqlite3_column_int64(pStmt, 1); break; case RBU_STATE_OALSZ: pRet->iOalSz = (u32)sqlite3_column_int64(pStmt, 1); break; case RBU_STATE_PHASEONESTEP: pRet->nPhaseOneStep = sqlite3_column_int64(pStmt, 1); break; case RBU_STATE_DATATBL: pRet->zDataTbl = rbuStrndup((char*)sqlite3_column_text(pStmt, 1), &rc); break; default: rc = SQLITE_CORRUPT; break; } } rc2 = sqlite3_finalize(pStmt); if( rc==SQLITE_OK ) rc = rc2; p->rc = rc; return pRet; } /* ** Open the database handle and attach the RBU database as "rbu". If an ** error occurs, leave an error code and message in the RBU handle. */ static void rbuOpenDatabase(sqlite3rbu *p, int *pbRetry){ assert( p->rc || (p->dbMain==0 && p->dbRbu==0) ); assert( p->rc || rbuIsVacuum(p) || p->zTarget!=0 ); /* Open the RBU database */ p->dbRbu = rbuOpenDbhandle(p, p->zRbu, 1); if( p->rc==SQLITE_OK && rbuIsVacuum(p) ){ sqlite3_file_control(p->dbRbu, "main", SQLITE_FCNTL_RBUCNT, (void*)p); if( p->zState==0 ){ const char *zFile = sqlite3_db_filename(p->dbRbu, "main"); p->zState = rbuMPrintf(p, "file://%s-vacuum?modeof=%s", zFile, zFile); } } /* If using separate RBU and state databases, attach the state database to ** the RBU db handle now. */ if( p->zState ){ rbuMPrintfExec(p, p->dbRbu, "ATTACH %Q AS stat", p->zState); memcpy(p->zStateDb, "stat", 4); }else{ memcpy(p->zStateDb, "main", 4); } #if 0 if( p->rc==SQLITE_OK && rbuIsVacuum(p) ){ p->rc = sqlite3_exec(p->dbRbu, "BEGIN", 0, 0, 0); } #endif /* If it has not already been created, create the rbu_state table */ rbuMPrintfExec(p, p->dbRbu, RBU_CREATE_STATE, p->zStateDb); #if 0 if( rbuIsVacuum(p) ){ if( p->rc==SQLITE_OK ){ int rc2; int bOk = 0; sqlite3_stmt *pCnt = 0; p->rc = prepareAndCollectError(p->dbRbu, &pCnt, &p->zErrmsg, "SELECT count(*) FROM stat.sqlite_master" ); if( p->rc==SQLITE_OK && sqlite3_step(pCnt)==SQLITE_ROW && 1==sqlite3_column_int(pCnt, 0) ){ bOk = 1; } rc2 = sqlite3_finalize(pCnt); if( p->rc==SQLITE_OK ) p->rc = rc2; if( p->rc==SQLITE_OK && bOk==0 ){ p->rc = SQLITE_ERROR; p->zErrmsg = sqlite3_mprintf("invalid state database"); } if( p->rc==SQLITE_OK ){ p->rc = sqlite3_exec(p->dbRbu, "COMMIT", 0, 0, 0); } } } #endif if( p->rc==SQLITE_OK && rbuIsVacuum(p) ){ int bOpen = 0; int rc; p->nRbu = 0; p->pRbuFd = 0; rc = sqlite3_file_control(p->dbRbu, "main", SQLITE_FCNTL_RBUCNT, (void*)p); if( rc!=SQLITE_NOTFOUND ) p->rc = rc; if( p->eStage>=RBU_STAGE_MOVE ){ bOpen = 1; }else{ RbuState *pState = rbuLoadState(p); if( pState ){ bOpen = (pState->eStage>=RBU_STAGE_MOVE); rbuFreeState(pState); } } if( bOpen ) p->dbMain = rbuOpenDbhandle(p, p->zRbu, p->nRbu<=1); } p->eStage = 0; if( p->rc==SQLITE_OK && p->dbMain==0 ){ if( !rbuIsVacuum(p) ){ p->dbMain = rbuOpenDbhandle(p, p->zTarget, 1); }else if( p->pRbuFd->pWalFd ){ if( pbRetry ){ p->pRbuFd->bNolock = 0; sqlite3_close(p->dbRbu); sqlite3_close(p->dbMain); p->dbMain = 0; p->dbRbu = 0; *pbRetry = 1; return; } p->rc = SQLITE_ERROR; p->zErrmsg = sqlite3_mprintf("cannot vacuum wal mode database"); }else{ char *zTarget; char *zExtra = 0; if( strlen(p->zRbu)>=5 && 0==memcmp("file:", p->zRbu, 5) ){ zExtra = &p->zRbu[5]; while( *zExtra ){ if( *zExtra++=='?' ) break; } if( *zExtra=='\0' ) zExtra = 0; } zTarget = sqlite3_mprintf("file:%s-vacuum?rbu_memory=1%s%s", sqlite3_db_filename(p->dbRbu, "main"), (zExtra==0 ? "" : "&"), (zExtra==0 ? "" : zExtra) ); if( zTarget==0 ){ p->rc = SQLITE_NOMEM; return; } p->dbMain = rbuOpenDbhandle(p, zTarget, p->nRbu<=1); sqlite3_free(zTarget); } } if( p->rc==SQLITE_OK ){ p->rc = sqlite3_create_function(p->dbMain, "rbu_tmp_insert", -1, SQLITE_UTF8, (void*)p, rbuTmpInsertFunc, 0, 0 ); } if( p->rc==SQLITE_OK ){ p->rc = sqlite3_create_function(p->dbMain, "rbu_fossil_delta", 2, SQLITE_UTF8, 0, rbuFossilDeltaFunc, 0, 0 ); } if( p->rc==SQLITE_OK ){ p->rc = sqlite3_create_function(p->dbRbu, "rbu_target_name", -1, SQLITE_UTF8, (void*)p, rbuTargetNameFunc, 0, 0 ); } if( p->rc==SQLITE_OK ){ p->rc = sqlite3_file_control(p->dbMain, "main", SQLITE_FCNTL_RBU, (void*)p); } rbuMPrintfExec(p, p->dbMain, "SELECT * FROM sqlite_master"); /* Mark the database file just opened as an RBU target database. If ** this call returns SQLITE_NOTFOUND, then the RBU vfs is not in use. ** This is an error. */ if( p->rc==SQLITE_OK ){ p->rc = sqlite3_file_control(p->dbMain, "main", SQLITE_FCNTL_RBU, (void*)p); } if( p->rc==SQLITE_NOTFOUND ){ p->rc = SQLITE_ERROR; p->zErrmsg = sqlite3_mprintf("rbu vfs not found"); } } /* ** This routine is a copy of the sqlite3FileSuffix3() routine from the core. ** It is a no-op unless SQLITE_ENABLE_8_3_NAMES is defined. ** ** If SQLITE_ENABLE_8_3_NAMES is set at compile-time and if the database ** filename in zBaseFilename is a URI with the "8_3_names=1" parameter and ** if filename in z[] has a suffix (a.k.a. "extension") that is longer than ** three characters, then shorten the suffix on z[] to be the last three ** characters of the original suffix. ** ** If SQLITE_ENABLE_8_3_NAMES is set to 2 at compile-time, then always ** do the suffix shortening regardless of URI parameter. ** ** Examples: ** ** test.db-journal => test.nal ** test.db-wal => test.wal ** test.db-shm => test.shm ** test.db-mj7f3319fa => test.9fa */ static void rbuFileSuffix3(const char *zBase, char *z){ #ifdef SQLITE_ENABLE_8_3_NAMES #if SQLITE_ENABLE_8_3_NAMES<2 if( sqlite3_uri_boolean(zBase, "8_3_names", 0) ) #endif { int i, sz; sz = (int)strlen(z)&0xffffff; for(i=sz-1; i>0 && z[i]!='/' && z[i]!='.'; i--){} if( z[i]=='.' && sz>i+4 ) memmove(&z[i+1], &z[sz-3], 4); } #endif } /* ** Return the current wal-index header checksum for the target database ** as a 64-bit integer. ** ** The checksum is store in the first page of xShmMap memory as an 8-byte ** blob starting at byte offset 40. */ static i64 rbuShmChecksum(sqlite3rbu *p){ i64 iRet = 0; if( p->rc==SQLITE_OK ){ sqlite3_file *pDb = p->pTargetFd->pReal; u32 volatile *ptr; p->rc = pDb->pMethods->xShmMap(pDb, 0, 32*1024, 0, (void volatile**)&ptr); if( p->rc==SQLITE_OK ){ iRet = ((i64)ptr[10] << 32) + ptr[11]; } } return iRet; } /* ** This function is called as part of initializing or reinitializing an ** incremental checkpoint. ** ** It populates the sqlite3rbu.aFrame[] array with the set of ** (wal frame -> db page) copy operations required to checkpoint the ** current wal file, and obtains the set of shm locks required to safely ** perform the copy operations directly on the file-system. ** ** If argument pState is not NULL, then the incremental checkpoint is ** being resumed. In this case, if the checksum of the wal-index-header ** following recovery is not the same as the checksum saved in the RbuState ** object, then the rbu handle is set to DONE state. This occurs if some ** other client appends a transaction to the wal file in the middle of ** an incremental checkpoint. */ static void rbuSetupCheckpoint(sqlite3rbu *p, RbuState *pState){ /* If pState is NULL, then the wal file may not have been opened and ** recovered. Running a read-statement here to ensure that doing so ** does not interfere with the "capture" process below. */ if( pState==0 ){ p->eStage = 0; if( p->rc==SQLITE_OK ){ p->rc = sqlite3_exec(p->dbMain, "SELECT * FROM sqlite_master", 0, 0, 0); } } /* Assuming no error has occurred, run a "restart" checkpoint with the ** sqlite3rbu.eStage variable set to CAPTURE. This turns on the following ** special behaviour in the rbu VFS: ** ** * If the exclusive shm WRITER or READ0 lock cannot be obtained, ** the checkpoint fails with SQLITE_BUSY (normally SQLite would ** proceed with running a passive checkpoint instead of failing). ** ** * Attempts to read from the *-wal file or write to the database file ** do not perform any IO. Instead, the frame/page combinations that ** would be read/written are recorded in the sqlite3rbu.aFrame[] ** array. ** ** * Calls to xShmLock(UNLOCK) to release the exclusive shm WRITER, ** READ0 and CHECKPOINT locks taken as part of the checkpoint are ** no-ops. These locks will not be released until the connection ** is closed. ** ** * Attempting to xSync() the database file causes an SQLITE_INTERNAL ** error. ** ** As a result, unless an error (i.e. OOM or SQLITE_BUSY) occurs, the ** checkpoint below fails with SQLITE_INTERNAL, and leaves the aFrame[] ** array populated with a set of (frame -> page) mappings. Because the ** WRITER, CHECKPOINT and READ0 locks are still held, it is safe to copy ** data from the wal file into the database file according to the ** contents of aFrame[]. */ if( p->rc==SQLITE_OK ){ int rc2; p->eStage = RBU_STAGE_CAPTURE; rc2 = sqlite3_exec(p->dbMain, "PRAGMA main.wal_checkpoint=restart", 0, 0,0); if( rc2!=SQLITE_INTERNAL ) p->rc = rc2; } if( p->rc==SQLITE_OK && p->nFrame>0 ){ p->eStage = RBU_STAGE_CKPT; p->nStep = (pState ? pState->nRow : 0); p->aBuf = rbuMalloc(p, p->pgsz); p->iWalCksum = rbuShmChecksum(p); } if( p->rc==SQLITE_OK ){ if( p->nFrame==0 || (pState && pState->iWalCksum!=p->iWalCksum) ){ p->rc = SQLITE_DONE; p->eStage = RBU_STAGE_DONE; }else{ int nSectorSize; sqlite3_file *pDb = p->pTargetFd->pReal; sqlite3_file *pWal = p->pTargetFd->pWalFd->pReal; assert( p->nPagePerSector==0 ); nSectorSize = pDb->pMethods->xSectorSize(pDb); if( nSectorSize>p->pgsz ){ p->nPagePerSector = nSectorSize / p->pgsz; }else{ p->nPagePerSector = 1; } /* Call xSync() on the wal file. This causes SQLite to sync the ** directory in which the target database and the wal file reside, in ** case it has not been synced since the rename() call in ** rbuMoveOalFile(). */ p->rc = pWal->pMethods->xSync(pWal, SQLITE_SYNC_NORMAL); } } } /* ** Called when iAmt bytes are read from offset iOff of the wal file while ** the rbu object is in capture mode. Record the frame number of the frame ** being read in the aFrame[] array. */ static int rbuCaptureWalRead(sqlite3rbu *pRbu, i64 iOff, int iAmt){ const u32 mReq = (1<mLock!=mReq ){ pRbu->rc = SQLITE_BUSY; return SQLITE_INTERNAL; } pRbu->pgsz = iAmt; if( pRbu->nFrame==pRbu->nFrameAlloc ){ int nNew = (pRbu->nFrameAlloc ? pRbu->nFrameAlloc : 64) * 2; RbuFrame *aNew; aNew = (RbuFrame*)sqlite3_realloc64(pRbu->aFrame, nNew * sizeof(RbuFrame)); if( aNew==0 ) return SQLITE_NOMEM; pRbu->aFrame = aNew; pRbu->nFrameAlloc = nNew; } iFrame = (u32)((iOff-32) / (i64)(iAmt+24)) + 1; if( pRbu->iMaxFrame