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Diffstat (limited to 'ext/rbu/sqlite3rbu.c')
| -rw-r--r-- | ext/rbu/sqlite3rbu.c | 5372 |
1 files changed, 5372 insertions, 0 deletions
diff --git a/ext/rbu/sqlite3rbu.c b/ext/rbu/sqlite3rbu.c new file mode 100644 index 0000000..4829520 --- /dev/null +++ b/ext/rbu/sqlite3rbu.c @@ -0,0 +1,5372 @@ +/* +** 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 "<database>-oal" instead of "<database>-wal". +** Because regular SQLite clients do not look for file named +** "<database>-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 "<database>-oal" file is moved to the equivalent "<database>-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 <assert.h> +#include <string.h> +#include <stdio.h> + +#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 + +/* +** Name of the URI option that causes RBU to take an exclusive lock as +** part of the incremental checkpoint operation. +*/ +#define RBU_EXCLUSIVE_CHECKPOINT "rbu_exclusive_checkpoint" + + +/* +** 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 RbuSpan RbuSpan; +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; +}; + +struct RbuSpan { + const char *zSpan; + int nSpan; +}; + +/* +** 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. +** +** If there are one or more partial indexes on the table, all fields of +** this array set set to 1. This is because in that case, the module has +** no way to tell which fields will be required to add and remove entries +** from the partial indexes. +** +*/ +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 */ + int nIdxCol; + RbuSpan *aIdxCol; + char *zIdxSql; + + /* 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; + void *pRenameArg; + int (*xRename)(void*, const char*, const char*); + + /* 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_free(aOut); + 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; i<pIter->nTblCol; 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; + } + sqlite3_free(pIter->aIdxCol); + sqlite3_free(pIter->zIdxSql); + + pIter->pSelect = 0; + pIter->pInsert = 0; + pIter->pDelete = 0; + pIter->pRbuUpdate = 0; + pIter->pTmpInsert = 0; + pIter->nCol = 0; + pIter->nIdxCol = 0; + pIter->aIdxCol = 0; + pIter->zIdxSql = 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]_<name> +** +** where <name> is any sequence of 1 or more characters, <name> 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) ){ + assert( argc==2 || argc==1 ); + 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_schema " + "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_schema " + " 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, sqlite3_int64 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){ + sqlite3_int64 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; + + if( *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_schema ){ +** 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_schema ){ +** *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_schema where name=%Q AND IsVirtual(%Q) + ** 1) PRAGMA index_list = ? + ** 2) SELECT count(*) FROM sqlite_schema 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 COLLATE nocase BETWEEN 'CREATE VIRTUAL' AND 'CREATE VIRTUAM')," + " rootpage" + " FROM sqlite_schema" + " 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_schema 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; i<sizeof(aStmt)/sizeof(aStmt[0]); i++){ + rbuFinalize(p, aStmt[i]); + } + } +} + +/* +** This is a helper function for rbuObjIterCacheTableInfo(). It populates +** the pIter->abIndexed[] 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); + int bPartial = sqlite3_column_int(pList, 4); + sqlite3_stmt *pXInfo = 0; + if( zIdx==0 ) break; + if( bPartial ){ + memset(pIter->abIndexed, 0x01, sizeof(u8)*pIter->nTblCol); + } + 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; + if( iCid==-2 ){ + memset(pIter->abIndexed, 0x01, sizeof(u8)*pIter->nTblCol); + } + } + 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 && i<nCol; i++){ + const char *zName = (const char*)sqlite3_column_name(pStmt, i); + if( sqlite3_strnicmp("rbu_", zName, 4) ){ + char *zCopy = rbuStrndup(zName, &p->rc); + 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; i<pIter->nTblCol; 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); + assert( iPk>=0 ); + pIter->abTblPk[iOrder] = (u8)iPk; + 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; i<pIter->nTblCol; i++){ + const char *z = pIter->azTblCol[i]; + zList = rbuMPrintf(p, "%z%s\"%w\"", zList, zSep, z); + zSep = ", "; + } + return zList; +} + +/* +** Return a comma separated list of the quoted PRIMARY KEY column names, +** in order, for the current table. Before each column name, add the text +** zPre. After each column name, add the zPost text. Use zSeparator as +** the separator text (usually ", "). +*/ +static char *rbuObjIterGetPkList( + sqlite3rbu *p, /* RBU object */ + RbuObjIter *pIter, /* Object iterator for column names */ + const char *zPre, /* Before each quoted column name */ + const char *zSeparator, /* Separator to use between columns */ + const char *zPost /* After each quoted column name */ +){ + int iPk = 1; + char *zRet = 0; + const char *zSep = ""; + while( 1 ){ + int i; + for(i=0; i<pIter->nTblCol; i++){ + if( (int)pIter->abTblPk[i]==iPk ){ + const char *zCol = pIter->azTblCol[i]; + zRet = rbuMPrintf(p, "%z%s%s\"%w\"%s", zRet, zSep, zPre, zCol, zPost); + zSep = zSeparator; + break; + } + } + if( i==pIter->nTblCol ) break; + iPk++; + } + return zRet; +} + +/* +** This function is called as part of restarting an RBU vacuum within +** stage 1 of the process (while the *-oal file is being built) while +** updating a table (not an index). The table may be a rowid table or +** a WITHOUT ROWID table. It queries the target database to find the +** largest key that has already been written to the target table and +** constructs a WHERE clause that can be used to extract the remaining +** rows from the source table. For a rowid table, the WHERE clause +** is of the form: +** +** "WHERE _rowid_ > ?" +** +** and for WITHOUT ROWID tables: +** +** "WHERE (key1, key2) > (?, ?)" +** +** Instead of "?" placeholders, the actual WHERE clauses created by +** this function contain literal SQL values. +*/ +static char *rbuVacuumTableStart( + sqlite3rbu *p, /* RBU handle */ + RbuObjIter *pIter, /* RBU iterator object */ + int bRowid, /* True for a rowid table */ + const char *zWrite /* Target table name prefix */ +){ + sqlite3_stmt *pMax = 0; + char *zRet = 0; + if( bRowid ){ + p->rc = prepareFreeAndCollectError(p->dbMain, &pMax, &p->zErrmsg, + sqlite3_mprintf( + "SELECT max(_rowid_) FROM \"%s%w\"", zWrite, pIter->zTbl + ) + ); + if( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pMax) ){ + sqlite3_int64 iMax = sqlite3_column_int64(pMax, 0); + zRet = rbuMPrintf(p, " WHERE _rowid_ > %lld ", iMax); + } + rbuFinalize(p, pMax); + }else{ + char *zOrder = rbuObjIterGetPkList(p, pIter, "", ", ", " DESC"); + char *zSelect = rbuObjIterGetPkList(p, pIter, "quote(", "||','||", ")"); + char *zList = rbuObjIterGetPkList(p, pIter, "", ", ", ""); + + if( p->rc==SQLITE_OK ){ + p->rc = prepareFreeAndCollectError(p->dbMain, &pMax, &p->zErrmsg, + sqlite3_mprintf( + "SELECT %s FROM \"%s%w\" ORDER BY %s LIMIT 1", + zSelect, zWrite, pIter->zTbl, zOrder + ) + ); + if( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pMax) ){ + const char *zVal = (const char*)sqlite3_column_text(pMax, 0); + zRet = rbuMPrintf(p, " WHERE (%s) > (%s) ", zList, zVal); + } + rbuFinalize(p, pMax); + } + + sqlite3_free(zOrder); + sqlite3_free(zSelect); + sqlite3_free(zList); + } + return zRet; +} + +/* +** This function is called as part of restating an RBU vacuum when the +** current operation is writing content to an index. If possible, it +** queries the target index b-tree for the largest key already written to +** it, then composes and returns an expression that can be used in a WHERE +** clause to select the remaining required rows from the source table. +** It is only possible to return such an expression if: +** +** * The index contains no DESC columns, and +** * The last key written to the index before the operation was +** suspended does not contain any NULL values. +** +** The expression is of the form: +** +** (index-field1, index-field2, ...) > (?, ?, ...) +** +** except that the "?" placeholders are replaced with literal values. +** +** If the expression cannot be created, NULL is returned. In this case, +** the caller has to use an OFFSET clause to extract only the required +** rows from the sourct table, just as it does for an RBU update operation. +*/ +static char *rbuVacuumIndexStart( + sqlite3rbu *p, /* RBU handle */ + RbuObjIter *pIter /* RBU iterator object */ +){ + char *zOrder = 0; + char *zLhs = 0; + char *zSelect = 0; + char *zVector = 0; + char *zRet = 0; + int bFailed = 0; + const char *zSep = ""; + int iCol = 0; + sqlite3_stmt *pXInfo = 0; + + p->rc = prepareFreeAndCollectError(p->dbMain, &pXInfo, &p->zErrmsg, + sqlite3_mprintf("PRAGMA main.index_xinfo = %Q", pIter->zIdx) + ); + while( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pXInfo) ){ + int iCid = sqlite3_column_int(pXInfo, 1); + const char *zCollate = (const char*)sqlite3_column_text(pXInfo, 4); + const char *zCol; + if( sqlite3_column_int(pXInfo, 3) ){ + bFailed = 1; + break; + } + + if( iCid<0 ){ + if( pIter->eType==RBU_PK_IPK ){ + int i; + for(i=0; pIter->abTblPk[i]==0; i++); + assert( i<pIter->nTblCol ); + zCol = pIter->azTblCol[i]; + }else{ + zCol = "_rowid_"; + } + }else{ + zCol = pIter->azTblCol[iCid]; + } + + zLhs = rbuMPrintf(p, "%z%s \"%w\" COLLATE %Q", + zLhs, zSep, zCol, zCollate + ); + zOrder = rbuMPrintf(p, "%z%s \"rbu_imp_%d%w\" COLLATE %Q DESC", + zOrder, zSep, iCol, zCol, zCollate + ); + zSelect = rbuMPrintf(p, "%z%s quote(\"rbu_imp_%d%w\")", + zSelect, zSep, iCol, zCol + ); + zSep = ", "; + iCol++; + } + rbuFinalize(p, pXInfo); + if( bFailed ) goto index_start_out; + + if( p->rc==SQLITE_OK ){ + sqlite3_stmt *pSel = 0; + + p->rc = prepareFreeAndCollectError(p->dbMain, &pSel, &p->zErrmsg, + sqlite3_mprintf("SELECT %s FROM \"rbu_imp_%w\" ORDER BY %s LIMIT 1", + zSelect, pIter->zTbl, zOrder + ) + ); + if( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pSel) ){ + zSep = ""; + for(iCol=0; iCol<pIter->nCol; iCol++){ + const char *zQuoted = (const char*)sqlite3_column_text(pSel, iCol); + if( zQuoted==0 ){ + p->rc = SQLITE_NOMEM; + }else if( zQuoted[0]=='N' ){ + bFailed = 1; + break; + } + zVector = rbuMPrintf(p, "%z%s%s", zVector, zSep, zQuoted); + zSep = ", "; + } + + if( !bFailed ){ + zRet = rbuMPrintf(p, "(%s) > (%s)", zLhs, zVector); + } + } + rbuFinalize(p, pSel); + } + + index_start_out: + sqlite3_free(zOrder); + sqlite3_free(zSelect); + sqlite3_free(zVector); + sqlite3_free(zLhs); + return zRet; +} + +/* +** 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 = <idxname>" 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 = 0; + const char *zType; + + if( iCid==-2 ){ + int iSeq = sqlite3_column_int(pXInfo, 0); + zRet = sqlite3_mprintf("%z%s(%.*s) COLLATE %Q", zRet, zCom, + pIter->aIdxCol[iSeq].nSpan, pIter->aIdxCol[iSeq].zSpan, zCollate + ); + zType = ""; + }else { + 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( i<pIter->nTblCol ); + 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; i<pIter->nTblCol; 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; i<pIter->nTblCol; 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; i<pIter->nTblCol; 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; i<pIter->nTblCol; 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; + sqlite3_int64 nByte = 2*(sqlite3_int64)nBind + 1; + + zRet = (char*)rbuMalloc(p, nByte); + if( zRet ){ + int i; + for(i=0; i<nBind; i++){ + zRet[i*2] = '?'; + zRet[i*2+1] = (i+1==nBind) ? '\0' : ','; + } + } + return zRet; +} + +/* +** The iterator currently points to a table (not index) of type +** RBU_PK_WITHOUT_ROWID. This function creates the PRIMARY KEY +** declaration for the corresponding imposter table. For example, +** if the iterator points to a table created as: +** +** CREATE TABLE t1(a, b, c, PRIMARY KEY(b, a DESC)) WITHOUT ROWID +** +** this function returns: +** +** PRIMARY KEY("b", "a" DESC) +*/ +static char *rbuWithoutRowidPK(sqlite3rbu *p, RbuObjIter *pIter){ + char *z = 0; + assert( pIter->zIdx==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 = <pk-index> */ + + 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_schema 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 && iCol<pIter->nTblCol; 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 && i<nVal; i++){ + rc = sqlite3_bind_value(p->objiter.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); + } +} + +static char *rbuObjIterGetIndexWhere(sqlite3rbu *p, RbuObjIter *pIter){ + sqlite3_stmt *pStmt = 0; + int rc = p->rc; + char *zRet = 0; + + assert( pIter->zIdxSql==0 && pIter->nIdxCol==0 && pIter->aIdxCol==0 ); + + if( rc==SQLITE_OK ){ + rc = prepareAndCollectError(p->dbMain, &pStmt, &p->zErrmsg, + "SELECT trim(sql) FROM sqlite_schema WHERE type='index' AND name=?" + ); + } + if( rc==SQLITE_OK ){ + int rc2; + rc = sqlite3_bind_text(pStmt, 1, pIter->zIdx, -1, SQLITE_STATIC); + if( rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pStmt) ){ + char *zSql = (char*)sqlite3_column_text(pStmt, 0); + if( zSql ){ + pIter->zIdxSql = zSql = rbuStrndup(zSql, &rc); + } + if( zSql ){ + int nParen = 0; /* Number of open parenthesis */ + int i; + int iIdxCol = 0; + int nIdxAlloc = 0; + for(i=0; zSql[i]; i++){ + char c = zSql[i]; + + /* If necessary, grow the pIter->aIdxCol[] array */ + if( iIdxCol==nIdxAlloc ){ + RbuSpan *aIdxCol = (RbuSpan*)sqlite3_realloc( + pIter->aIdxCol, (nIdxAlloc+16)*sizeof(RbuSpan) + ); + if( aIdxCol==0 ){ + rc = SQLITE_NOMEM; + break; + } + pIter->aIdxCol = aIdxCol; + nIdxAlloc += 16; + } + + if( c=='(' ){ + if( nParen==0 ){ + assert( iIdxCol==0 ); + pIter->aIdxCol[0].zSpan = &zSql[i+1]; + } + nParen++; + } + else if( c==')' ){ + nParen--; + if( nParen==0 ){ + int nSpan = &zSql[i] - pIter->aIdxCol[iIdxCol].zSpan; + pIter->aIdxCol[iIdxCol++].nSpan = nSpan; + i++; + break; + } + }else if( c==',' && nParen==1 ){ + int nSpan = &zSql[i] - pIter->aIdxCol[iIdxCol].zSpan; + pIter->aIdxCol[iIdxCol++].nSpan = nSpan; + pIter->aIdxCol[iIdxCol].zSpan = &zSql[i+1]; + }else if( c=='"' || c=='\'' || c=='`' ){ + for(i++; 1; i++){ + if( zSql[i]==c ){ + if( zSql[i+1]!=c ) break; + i++; + } + } + }else if( c=='[' ){ + for(i++; 1; i++){ + if( zSql[i]==']' ) break; + } + }else if( c=='-' && zSql[i+1]=='-' ){ + for(i=i+2; zSql[i] && zSql[i]!='\n'; i++); + if( zSql[i]=='\0' ) break; + }else if( c=='/' && zSql[i+1]=='*' ){ + for(i=i+2; zSql[i] && (zSql[i]!='*' || zSql[i+1]!='/'); i++); + if( zSql[i]=='\0' ) break; + i++; + } + } + if( zSql[i] ){ + zRet = rbuStrndup(&zSql[i], &rc); + } + pIter->nIdxCol = iIdxCol; + } + } + + rc2 = sqlite3_finalize(pStmt); + if( rc==SQLITE_OK ) rc = rc2; + } + + p->rc = rc; + return zRet; +} + +/* +** 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; + char *zPart = 0; + int nBind = 0; + + assert( pIter->eType!=RBU_PK_VTAB ); + zPart = rbuObjIterGetIndexWhere(p, pIter); + 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) ){ + char *zStart = 0; + if( nOffset ){ + zStart = rbuVacuumIndexStart(p, pIter); + if( zStart ){ + sqlite3_free(zLimit); + zLimit = 0; + } + } + + zSql = sqlite3_mprintf( + "SELECT %s, 0 AS rbu_control FROM '%q' %s %s %s ORDER BY %s%s", + zCollist, + pIter->zDataTbl, + zPart, + (zStart ? (zPart ? "AND" : "WHERE") : ""), zStart, + zCollist, zLimit + ); + sqlite3_free(zStart); + }else + + if( pIter->eType==RBU_PK_EXTERNAL || pIter->eType==RBU_PK_NONE ){ + zSql = sqlite3_mprintf( + "SELECT %s, rbu_control FROM %s.'rbu_tmp_%q' %s ORDER BY %s%s", + zCollist, p->zStateDb, pIter->zDataTbl, + zPart, zCollist, zLimit + ); + }else{ + zSql = sqlite3_mprintf( + "SELECT %s, rbu_control FROM %s.'rbu_tmp_%q' %s " + "UNION ALL " + "SELECT %s, rbu_control FROM '%q' " + "%s %s typeof(rbu_control)='integer' AND rbu_control!=1 " + "ORDER BY %s%s", + zCollist, p->zStateDb, pIter->zDataTbl, zPart, + zCollist, pIter->zDataTbl, + zPart, + (zPart ? "AND" : "WHERE"), + zCollist, zLimit + ); + } + if( p->rc==SQLITE_OK ){ + p->rc = prepareFreeAndCollectError(p->dbRbu,&pIter->pSelect,pz,zSql); + }else{ + sqlite3_free(zSql); + } + } + + sqlite3_free(zImposterCols); + sqlite3_free(zImposterPK); + sqlite3_free(zWhere); + sqlite3_free(zBind); + sqlite3_free(zPart); + }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 = ""; + char *zStart = 0; + char *zOrder = 0; + if( bRbuRowid ){ + zRbuRowid = rbuIsVacuum(p) ? ",_rowid_ " : ",rbu_rowid"; + } + + if( rbuIsVacuum(p) ){ + if( nOffset ){ + zStart = rbuVacuumTableStart(p, pIter, bRbuRowid, zWrite); + if( zStart ){ + sqlite3_free(zLimit); + zLimit = 0; + } + } + if( bRbuRowid ){ + zOrder = rbuMPrintf(p, "_rowid_"); + }else{ + zOrder = rbuObjIterGetPkList(p, pIter, "", ", ", ""); + } + } + + if( p->rc==SQLITE_OK ){ + p->rc = prepareFreeAndCollectError(p->dbRbu, &pIter->pSelect, pz, + sqlite3_mprintf( + "SELECT %s,%s rbu_control%s FROM '%q'%s %s %s %s", + zCollist, + (rbuIsVacuum(p) ? "0 AS " : ""), + zRbuRowid, + pIter->zDataTbl, (zStart ? zStart : ""), + (zOrder ? "ORDER BY" : ""), zOrder, + zLimit + ) + ); + } + sqlite3_free(zStart); + sqlite3_free(zOrder); + } + + 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 = 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. +** +** If argument dbMain is not NULL, then it is a database handle already +** open on the target database. Use this handle instead of opening a new +** one. +*/ +static void rbuOpenDatabase(sqlite3rbu *p, sqlite3 *dbMain, int *pbRetry){ + assert( p->rc || (p->dbMain==0 && p->dbRbu==0) ); + assert( p->rc || rbuIsVacuum(p) || p->zTarget!=0 ); + assert( dbMain==0 || rbuIsVacuum(p)==0 ); + + /* Open the RBU database */ + p->dbRbu = rbuOpenDbhandle(p, p->zRbu, 1); + p->dbMain = dbMain; + + 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_schema" + ); + 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-vactmp?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_schema"); + + /* 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_schema", 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<<WAL_LOCK_WRITE)|(1<<WAL_LOCK_CKPT)|(1<<WAL_LOCK_READ0); + u32 iFrame; + + if( pRbu->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<iFrame ) pRbu->iMaxFrame = iFrame; + pRbu->aFrame[pRbu->nFrame].iWalFrame = iFrame; + pRbu->aFrame[pRbu->nFrame].iDbPage = 0; + pRbu->nFrame++; + return SQLITE_OK; +} + +/* +** Called when a page of data is written to offset iOff of the database +** file while the rbu handle is in capture mode. Record the page number +** of the page being written in the aFrame[] array. +*/ +static int rbuCaptureDbWrite(sqlite3rbu *pRbu, i64 iOff){ + pRbu->aFrame[pRbu->nFrame-1].iDbPage = (u32)(iOff / pRbu->pgsz) + 1; + return SQLITE_OK; +} + +/* +** This is called as part of an incremental checkpoint operation. Copy +** a single frame of data from the wal file into the database file, as +** indicated by the RbuFrame object. +*/ +static void rbuCheckpointFrame(sqlite3rbu *p, RbuFrame *pFrame){ + sqlite3_file *pWal = p->pTargetFd->pWalFd->pReal; + sqlite3_file *pDb = p->pTargetFd->pReal; + i64 iOff; + + assert( p->rc==SQLITE_OK ); + iOff = (i64)(pFrame->iWalFrame-1) * (p->pgsz + 24) + 32 + 24; + p->rc = pWal->pMethods->xRead(pWal, p->aBuf, p->pgsz, iOff); + if( p->rc ) return; + + iOff = (i64)(pFrame->iDbPage-1) * p->pgsz; + p->rc = pDb->pMethods->xWrite(pDb, p->aBuf, p->pgsz, iOff); +} + + +/* +** Take an EXCLUSIVE lock on the database file. Return SQLITE_OK if +** successful, or an SQLite error code otherwise. +*/ +static int rbuLockDatabase(sqlite3 *db){ + int rc = SQLITE_OK; + sqlite3_file *fd = 0; + sqlite3_file_control(db, "main", SQLITE_FCNTL_FILE_POINTER, &fd); + + if( fd->pMethods ){ + rc = fd->pMethods->xLock(fd, SQLITE_LOCK_SHARED); + if( rc==SQLITE_OK ){ + rc = fd->pMethods->xLock(fd, SQLITE_LOCK_EXCLUSIVE); + } + } + return rc; +} + +/* +** Return true if the database handle passed as the only argument +** was opened with the rbu_exclusive_checkpoint=1 URI parameter +** specified. Or false otherwise. +*/ +static int rbuExclusiveCheckpoint(sqlite3 *db){ + const char *zUri = sqlite3_db_filename(db, 0); + return sqlite3_uri_boolean(zUri, RBU_EXCLUSIVE_CHECKPOINT, 0); +} + +#if defined(_WIN32_WCE) +static LPWSTR rbuWinUtf8ToUnicode(const char *zFilename){ + int nChar; + LPWSTR zWideFilename; + + nChar = MultiByteToWideChar(CP_UTF8, 0, zFilename, -1, NULL, 0); + if( nChar==0 ){ + return 0; + } + zWideFilename = sqlite3_malloc64( nChar*sizeof(zWideFilename[0]) ); + if( zWideFilename==0 ){ + return 0; + } + memset(zWideFilename, 0, nChar*sizeof(zWideFilename[0])); + nChar = MultiByteToWideChar(CP_UTF8, 0, zFilename, -1, zWideFilename, + nChar); + if( nChar==0 ){ + sqlite3_free(zWideFilename); + zWideFilename = 0; + } + return zWideFilename; +} +#endif + +/* +** The RBU handle is currently in RBU_STAGE_OAL state, with a SHARED lock +** on the database file. This proc moves the *-oal file to the *-wal path, +** then reopens the database file (this time in vanilla, non-oal, WAL mode). +** If an error occurs, leave an error code and error message in the rbu +** handle. +*/ +static void rbuMoveOalFile(sqlite3rbu *p){ + const char *zBase = sqlite3_db_filename(p->dbMain, "main"); + const char *zMove = zBase; + char *zOal; + char *zWal; + + if( rbuIsVacuum(p) ){ + zMove = sqlite3_db_filename(p->dbRbu, "main"); + } + zOal = sqlite3_mprintf("%s-oal", zMove); + zWal = sqlite3_mprintf("%s-wal", zMove); + + assert( p->eStage==RBU_STAGE_MOVE ); + assert( p->rc==SQLITE_OK && p->zErrmsg==0 ); + if( zWal==0 || zOal==0 ){ + p->rc = SQLITE_NOMEM; + }else{ + /* Move the *-oal file to *-wal. At this point connection p->db is + ** holding a SHARED lock on the target database file (because it is + ** in WAL mode). So no other connection may be writing the db. + ** + ** In order to ensure that there are no database readers, an EXCLUSIVE + ** lock is obtained here before the *-oal is moved to *-wal. + */ + sqlite3 *dbMain = 0; + rbuFileSuffix3(zBase, zWal); + rbuFileSuffix3(zBase, zOal); + + /* Re-open the databases. */ + rbuObjIterFinalize(&p->objiter); + sqlite3_close(p->dbRbu); + sqlite3_close(p->dbMain); + p->dbMain = 0; + p->dbRbu = 0; + + dbMain = rbuOpenDbhandle(p, p->zTarget, 1); + if( dbMain ){ + assert( p->rc==SQLITE_OK ); + p->rc = rbuLockDatabase(dbMain); + } + + if( p->rc==SQLITE_OK ){ + p->rc = p->xRename(p->pRenameArg, zOal, zWal); + } + + if( p->rc!=SQLITE_OK + || rbuIsVacuum(p) + || rbuExclusiveCheckpoint(dbMain)==0 + ){ + sqlite3_close(dbMain); + dbMain = 0; + } + + if( p->rc==SQLITE_OK ){ + rbuOpenDatabase(p, dbMain, 0); + rbuSetupCheckpoint(p, 0); + } + } + + sqlite3_free(zWal); + sqlite3_free(zOal); +} + +/* +** The SELECT statement iterating through the keys for the current object +** (p->objiter.pSelect) currently points to a valid row. This function +** determines the type of operation requested by this row and returns +** one of the following values to indicate the result: +** +** * RBU_INSERT +** * RBU_DELETE +** * RBU_IDX_DELETE +** * RBU_UPDATE +** +** If RBU_UPDATE is returned, then output variable *pzMask is set to +** point to the text value indicating the columns to update. +** +** If the rbu_control field contains an invalid value, an error code and +** message are left in the RBU handle and zero returned. +*/ +static int rbuStepType(sqlite3rbu *p, const char **pzMask){ + int iCol = p->objiter.nCol; /* Index of rbu_control column */ + int res = 0; /* Return value */ + + switch( sqlite3_column_type(p->objiter.pSelect, iCol) ){ + case SQLITE_INTEGER: { + int iVal = sqlite3_column_int(p->objiter.pSelect, iCol); + switch( iVal ){ + case 0: res = RBU_INSERT; break; + case 1: res = RBU_DELETE; break; + case 2: res = RBU_REPLACE; break; + case 3: res = RBU_IDX_DELETE; break; + case 4: res = RBU_IDX_INSERT; break; + } + break; + } + + case SQLITE_TEXT: { + const unsigned char *z = sqlite3_column_text(p->objiter.pSelect, iCol); + if( z==0 ){ + p->rc = SQLITE_NOMEM; + }else{ + *pzMask = (const char*)z; + } + res = RBU_UPDATE; + + break; + } + + default: + break; + } + + if( res==0 ){ + rbuBadControlError(p); + } + return res; +} + +#ifdef SQLITE_DEBUG +/* +** Assert that column iCol of statement pStmt is named zName. +*/ +static void assertColumnName(sqlite3_stmt *pStmt, int iCol, const char *zName){ + const char *zCol = sqlite3_column_name(pStmt, iCol); + assert( 0==sqlite3_stricmp(zName, zCol) ); +} +#else +# define assertColumnName(x,y,z) +#endif + +/* +** Argument eType must be one of RBU_INSERT, RBU_DELETE, RBU_IDX_INSERT or +** RBU_IDX_DELETE. This function performs the work of a single +** sqlite3rbu_step() call for the type of operation specified by eType. +*/ +static void rbuStepOneOp(sqlite3rbu *p, int eType){ + RbuObjIter *pIter = &p->objiter; + sqlite3_value *pVal; + sqlite3_stmt *pWriter; + int i; + + assert( p->rc==SQLITE_OK ); + assert( eType!=RBU_DELETE || pIter->zIdx==0 ); + assert( eType==RBU_DELETE || eType==RBU_IDX_DELETE + || eType==RBU_INSERT || eType==RBU_IDX_INSERT + ); + + /* If this is a delete, decrement nPhaseOneStep by nIndex. If the DELETE + ** statement below does actually delete a row, nPhaseOneStep will be + ** incremented by the same amount when SQL function rbu_tmp_insert() + ** is invoked by the trigger. */ + if( eType==RBU_DELETE ){ + p->nPhaseOneStep -= p->objiter.nIndex; + } + + if( eType==RBU_IDX_DELETE || eType==RBU_DELETE ){ + pWriter = pIter->pDelete; + }else{ + pWriter = pIter->pInsert; + } + + for(i=0; i<pIter->nCol; i++){ + /* If this is an INSERT into a table b-tree and the table has an + ** explicit INTEGER PRIMARY KEY, check that this is not an attempt + ** to write a NULL into the IPK column. That is not permitted. */ + if( eType==RBU_INSERT + && pIter->zIdx==0 && pIter->eType==RBU_PK_IPK && pIter->abTblPk[i] + && sqlite3_column_type(pIter->pSelect, i)==SQLITE_NULL + ){ + p->rc = SQLITE_MISMATCH; + p->zErrmsg = sqlite3_mprintf("datatype mismatch"); + return; + } + + if( eType==RBU_DELETE && pIter->abTblPk[i]==0 ){ + continue; + } + + pVal = sqlite3_column_value(pIter->pSelect, i); + p->rc = sqlite3_bind_value(pWriter, i+1, pVal); + if( p->rc ) return; + } + if( pIter->zIdx==0 ){ + if( pIter->eType==RBU_PK_VTAB + || pIter->eType==RBU_PK_NONE + || (pIter->eType==RBU_PK_EXTERNAL && rbuIsVacuum(p)) + ){ + /* For a virtual table, or a table with no primary key, the + ** SELECT statement is: + ** + ** SELECT <cols>, rbu_control, rbu_rowid FROM .... + ** + ** Hence column_value(pIter->nCol+1). + */ + assertColumnName(pIter->pSelect, pIter->nCol+1, + rbuIsVacuum(p) ? "rowid" : "rbu_rowid" + ); + pVal = sqlite3_column_value(pIter->pSelect, pIter->nCol+1); + p->rc = sqlite3_bind_value(pWriter, pIter->nCol+1, pVal); + } + } + if( p->rc==SQLITE_OK ){ + sqlite3_step(pWriter); + p->rc = resetAndCollectError(pWriter, &p->zErrmsg); + } +} + +/* +** This function does the work for an sqlite3rbu_step() call. +** +** The object-iterator (p->objiter) currently points to a valid object, +** and the input cursor (p->objiter.pSelect) currently points to a valid +** input row. Perform whatever processing is required and return. +** +** If no error occurs, SQLITE_OK is returned. Otherwise, an error code +** and message is left in the RBU handle and a copy of the error code +** returned. +*/ +static int rbuStep(sqlite3rbu *p){ + RbuObjIter *pIter = &p->objiter; + const char *zMask = 0; + int eType = rbuStepType(p, &zMask); + + if( eType ){ + assert( eType==RBU_INSERT || eType==RBU_DELETE + || eType==RBU_REPLACE || eType==RBU_IDX_DELETE + || eType==RBU_IDX_INSERT || eType==RBU_UPDATE + ); + assert( eType!=RBU_UPDATE || pIter->zIdx==0 ); + + if( pIter->zIdx==0 && (eType==RBU_IDX_DELETE || eType==RBU_IDX_INSERT) ){ + rbuBadControlError(p); + } + else if( eType==RBU_REPLACE ){ + if( pIter->zIdx==0 ){ + p->nPhaseOneStep += p->objiter.nIndex; + rbuStepOneOp(p, RBU_DELETE); + } + if( p->rc==SQLITE_OK ) rbuStepOneOp(p, RBU_INSERT); + } + else if( eType!=RBU_UPDATE ){ + rbuStepOneOp(p, eType); + } + else{ + sqlite3_value *pVal; + sqlite3_stmt *pUpdate = 0; + assert( eType==RBU_UPDATE ); + p->nPhaseOneStep -= p->objiter.nIndex; + rbuGetUpdateStmt(p, pIter, zMask, &pUpdate); + if( pUpdate ){ + int i; + for(i=0; p->rc==SQLITE_OK && i<pIter->nCol; i++){ + char c = zMask[pIter->aiSrcOrder[i]]; + pVal = sqlite3_column_value(pIter->pSelect, i); + if( pIter->abTblPk[i] || c!='.' ){ + p->rc = sqlite3_bind_value(pUpdate, i+1, pVal); + } + } + if( p->rc==SQLITE_OK + && (pIter->eType==RBU_PK_VTAB || pIter->eType==RBU_PK_NONE) + ){ + /* Bind the rbu_rowid value to column _rowid_ */ + assertColumnName(pIter->pSelect, pIter->nCol+1, "rbu_rowid"); + pVal = sqlite3_column_value(pIter->pSelect, pIter->nCol+1); + p->rc = sqlite3_bind_value(pUpdate, pIter->nCol+1, pVal); + } + if( p->rc==SQLITE_OK ){ + sqlite3_step(pUpdate); + p->rc = resetAndCollectError(pUpdate, &p->zErrmsg); + } + } + } + } + return p->rc; +} + +/* +** Increment the schema cookie of the main database opened by p->dbMain. +** +** Or, if this is an RBU vacuum, set the schema cookie of the main db +** opened by p->dbMain to one more than the schema cookie of the main +** db opened by p->dbRbu. +*/ +static void rbuIncrSchemaCookie(sqlite3rbu *p){ + if( p->rc==SQLITE_OK ){ + sqlite3 *dbread = (rbuIsVacuum(p) ? p->dbRbu : p->dbMain); + int iCookie = 1000000; + sqlite3_stmt *pStmt; + + p->rc = prepareAndCollectError(dbread, &pStmt, &p->zErrmsg, + "PRAGMA schema_version" + ); + if( p->rc==SQLITE_OK ){ + /* Coverage: it may be that this sqlite3_step() cannot fail. There + ** is already a transaction open, so the prepared statement cannot + ** throw an SQLITE_SCHEMA exception. The only database page the + ** statement reads is page 1, which is guaranteed to be in the cache. + ** And no memory allocations are required. */ + if( SQLITE_ROW==sqlite3_step(pStmt) ){ + iCookie = sqlite3_column_int(pStmt, 0); + } + rbuFinalize(p, pStmt); + } + if( p->rc==SQLITE_OK ){ + rbuMPrintfExec(p, p->dbMain, "PRAGMA schema_version = %d", iCookie+1); + } + } +} + +/* +** Update the contents of the rbu_state table within the rbu database. The +** value stored in the RBU_STATE_STAGE column is eStage. All other values +** are determined by inspecting the rbu handle passed as the first argument. +*/ +static void rbuSaveState(sqlite3rbu *p, int eStage){ + if( p->rc==SQLITE_OK || p->rc==SQLITE_DONE ){ + sqlite3_stmt *pInsert = 0; + rbu_file *pFd = (rbuIsVacuum(p) ? p->pRbuFd : p->pTargetFd); + int rc; + + assert( p->zErrmsg==0 ); + rc = prepareFreeAndCollectError(p->dbRbu, &pInsert, &p->zErrmsg, + sqlite3_mprintf( + "INSERT OR REPLACE INTO %s.rbu_state(k, v) VALUES " + "(%d, %d), " + "(%d, %Q), " + "(%d, %Q), " + "(%d, %d), " + "(%d, %d), " + "(%d, %lld), " + "(%d, %lld), " + "(%d, %lld), " + "(%d, %lld), " + "(%d, %Q) ", + p->zStateDb, + RBU_STATE_STAGE, eStage, + RBU_STATE_TBL, p->objiter.zTbl, + RBU_STATE_IDX, p->objiter.zIdx, + RBU_STATE_ROW, p->nStep, + RBU_STATE_PROGRESS, p->nProgress, + RBU_STATE_CKPT, p->iWalCksum, + RBU_STATE_COOKIE, (i64)pFd->iCookie, + RBU_STATE_OALSZ, p->iOalSz, + RBU_STATE_PHASEONESTEP, p->nPhaseOneStep, + RBU_STATE_DATATBL, p->objiter.zDataTbl + ) + ); + assert( pInsert==0 || rc==SQLITE_OK ); + + if( rc==SQLITE_OK ){ + sqlite3_step(pInsert); + rc = sqlite3_finalize(pInsert); + } + if( rc!=SQLITE_OK ) p->rc = rc; + } +} + + +/* +** The second argument passed to this function is the name of a PRAGMA +** setting - "page_size", "auto_vacuum", "user_version" or "application_id". +** This function executes the following on sqlite3rbu.dbRbu: +** +** "PRAGMA main.$zPragma" +** +** where $zPragma is the string passed as the second argument, then +** on sqlite3rbu.dbMain: +** +** "PRAGMA main.$zPragma = $val" +** +** where $val is the value returned by the first PRAGMA invocation. +** +** In short, it copies the value of the specified PRAGMA setting from +** dbRbu to dbMain. +*/ +static void rbuCopyPragma(sqlite3rbu *p, const char *zPragma){ + if( p->rc==SQLITE_OK ){ + sqlite3_stmt *pPragma = 0; + p->rc = prepareFreeAndCollectError(p->dbRbu, &pPragma, &p->zErrmsg, + sqlite3_mprintf("PRAGMA main.%s", zPragma) + ); + if( p->rc==SQLITE_OK && SQLITE_ROW==sqlite3_step(pPragma) ){ + p->rc = rbuMPrintfExec(p, p->dbMain, "PRAGMA main.%s = %d", + zPragma, sqlite3_column_int(pPragma, 0) + ); + } + rbuFinalize(p, pPragma); + } +} + +/* +** The RBU handle passed as the only argument has just been opened and +** the state database is empty. If this RBU handle was opened for an +** RBU vacuum operation, create the schema in the target db. +*/ +static void rbuCreateTargetSchema(sqlite3rbu *p){ + sqlite3_stmt *pSql = 0; + sqlite3_stmt *pInsert = 0; + + assert( rbuIsVacuum(p) ); + p->rc = sqlite3_exec(p->dbMain, "PRAGMA writable_schema=1", 0,0, &p->zErrmsg); + if( p->rc==SQLITE_OK ){ + p->rc = prepareAndCollectError(p->dbRbu, &pSql, &p->zErrmsg, + "SELECT sql FROM sqlite_schema WHERE sql!='' AND rootpage!=0" + " AND name!='sqlite_sequence' " + " ORDER BY type DESC" + ); + } + + while( p->rc==SQLITE_OK && sqlite3_step(pSql)==SQLITE_ROW ){ + const char *zSql = (const char*)sqlite3_column_text(pSql, 0); + p->rc = sqlite3_exec(p->dbMain, zSql, 0, 0, &p->zErrmsg); + } + rbuFinalize(p, pSql); + if( p->rc!=SQLITE_OK ) return; + + if( p->rc==SQLITE_OK ){ + p->rc = prepareAndCollectError(p->dbRbu, &pSql, &p->zErrmsg, + "SELECT * FROM sqlite_schema WHERE rootpage=0 OR rootpage IS NULL" + ); + } + + if( p->rc==SQLITE_OK ){ + p->rc = prepareAndCollectError(p->dbMain, &pInsert, &p->zErrmsg, + "INSERT INTO sqlite_schema VALUES(?,?,?,?,?)" + ); + } + + while( p->rc==SQLITE_OK && sqlite3_step(pSql)==SQLITE_ROW ){ + int i; + for(i=0; i<5; i++){ + sqlite3_bind_value(pInsert, i+1, sqlite3_column_value(pSql, i)); + } + sqlite3_step(pInsert); + p->rc = sqlite3_reset(pInsert); + } + if( p->rc==SQLITE_OK ){ + p->rc = sqlite3_exec(p->dbMain, "PRAGMA writable_schema=0",0,0,&p->zErrmsg); + } + + rbuFinalize(p, pSql); + rbuFinalize(p, pInsert); +} + +/* +** Step the RBU object. +*/ +int sqlite3rbu_step(sqlite3rbu *p){ + if( p ){ + switch( p->eStage ){ + case RBU_STAGE_OAL: { + RbuObjIter *pIter = &p->objiter; + + /* If this is an RBU vacuum operation and the state table was empty + ** when this handle was opened, create the target database schema. */ + if( rbuIsVacuum(p) && p->nProgress==0 && p->rc==SQLITE_OK ){ + rbuCreateTargetSchema(p); + rbuCopyPragma(p, "user_version"); + rbuCopyPragma(p, "application_id"); + } + + while( p->rc==SQLITE_OK && pIter->zTbl ){ + + if( pIter->bCleanup ){ + /* Clean up the rbu_tmp_xxx table for the previous table. It + ** cannot be dropped as there are currently active SQL statements. + ** But the contents can be deleted. */ + if( rbuIsVacuum(p)==0 && pIter->abIndexed ){ + rbuMPrintfExec(p, p->dbRbu, + "DELETE FROM %s.'rbu_tmp_%q'", p->zStateDb, pIter->zDataTbl + ); + } + }else{ + rbuObjIterPrepareAll(p, pIter, 0); + + /* Advance to the next row to process. */ + if( p->rc==SQLITE_OK ){ + int rc = sqlite3_step(pIter->pSelect); + if( rc==SQLITE_ROW ){ + p->nProgress++; + p->nStep++; + return rbuStep(p); + } + p->rc = sqlite3_reset(pIter->pSelect); + p->nStep = 0; + } + } + + rbuObjIterNext(p, pIter); + } + + if( p->rc==SQLITE_OK ){ + assert( pIter->zTbl==0 ); + rbuSaveState(p, RBU_STAGE_MOVE); + rbuIncrSchemaCookie(p); + if( p->rc==SQLITE_OK ){ + p->rc = sqlite3_exec(p->dbMain, "COMMIT", 0, 0, &p->zErrmsg); + } + if( p->rc==SQLITE_OK ){ + p->rc = sqlite3_exec(p->dbRbu, "COMMIT", 0, 0, &p->zErrmsg); + } + p->eStage = RBU_STAGE_MOVE; + } + break; + } + + case RBU_STAGE_MOVE: { + if( p->rc==SQLITE_OK ){ + rbuMoveOalFile(p); + p->nProgress++; + } + break; + } + + case RBU_STAGE_CKPT: { + if( p->rc==SQLITE_OK ){ + if( p->nStep>=p->nFrame ){ + sqlite3_file *pDb = p->pTargetFd->pReal; + + /* Sync the db file */ + p->rc = pDb->pMethods->xSync(pDb, SQLITE_SYNC_NORMAL); + + /* Update nBackfill */ + if( p->rc==SQLITE_OK ){ + void volatile *ptr; + p->rc = pDb->pMethods->xShmMap(pDb, 0, 32*1024, 0, &ptr); + if( p->rc==SQLITE_OK ){ + ((u32 volatile*)ptr)[24] = p->iMaxFrame; + } + } + + if( p->rc==SQLITE_OK ){ + p->eStage = RBU_STAGE_DONE; + p->rc = SQLITE_DONE; + } + }else{ + /* At one point the following block copied a single frame from the + ** wal file to the database file. So that one call to sqlite3rbu_step() + ** checkpointed a single frame. + ** + ** However, if the sector-size is larger than the page-size, and the + ** application calls sqlite3rbu_savestate() or close() immediately + ** after this step, then rbu_step() again, then a power failure occurs, + ** then the database page written here may be damaged. Work around + ** this by checkpointing frames until the next page in the aFrame[] + ** lies on a different disk sector to the current one. */ + u32 iSector; + do{ + RbuFrame *pFrame = &p->aFrame[p->nStep]; + iSector = (pFrame->iDbPage-1) / p->nPagePerSector; + rbuCheckpointFrame(p, pFrame); + p->nStep++; + }while( p->nStep<p->nFrame + && iSector==((p->aFrame[p->nStep].iDbPage-1) / p->nPagePerSector) + && p->rc==SQLITE_OK + ); + } + p->nProgress++; + } + break; + } + + default: + break; + } + return p->rc; + }else{ + return SQLITE_NOMEM; + } +} + +/* +** Compare strings z1 and z2, returning 0 if they are identical, or non-zero +** otherwise. Either or both argument may be NULL. Two NULL values are +** considered equal, and NULL is considered distinct from all other values. +*/ +static int rbuStrCompare(const char *z1, const char *z2){ + if( z1==0 && z2==0 ) return 0; + if( z1==0 || z2==0 ) return 1; + return (sqlite3_stricmp(z1, z2)!=0); +} + +/* +** This function is called as part of sqlite3rbu_open() when initializing +** an rbu handle in OAL stage. If the rbu update has not started (i.e. +** the rbu_state table was empty) it is a no-op. Otherwise, it arranges +** things so that the next call to sqlite3rbu_step() continues on from +** where the previous rbu handle left off. +** +** If an error occurs, an error code and error message are left in the +** rbu handle passed as the first argument. +*/ +static void rbuSetupOal(sqlite3rbu *p, RbuState *pState){ + assert( p->rc==SQLITE_OK ); + if( pState->zTbl ){ + RbuObjIter *pIter = &p->objiter; + int rc = SQLITE_OK; + + while( rc==SQLITE_OK && pIter->zTbl && (pIter->bCleanup + || rbuStrCompare(pIter->zIdx, pState->zIdx) + || (pState->zDataTbl==0 && rbuStrCompare(pIter->zTbl, pState->zTbl)) + || (pState->zDataTbl && rbuStrCompare(pIter->zDataTbl, pState->zDataTbl)) + )){ + rc = rbuObjIterNext(p, pIter); + } + + if( rc==SQLITE_OK && !pIter->zTbl ){ + rc = SQLITE_ERROR; + p->zErrmsg = sqlite3_mprintf("rbu_state mismatch error"); + } + + if( rc==SQLITE_OK ){ + p->nStep = pState->nRow; + rc = rbuObjIterPrepareAll(p, &p->objiter, p->nStep); + } + + p->rc = rc; + } +} + +/* +** If there is a "*-oal" file in the file-system corresponding to the +** target database in the file-system, delete it. If an error occurs, +** leave an error code and error message in the rbu handle. +*/ +static void rbuDeleteOalFile(sqlite3rbu *p){ + char *zOal = rbuMPrintf(p, "%s-oal", p->zTarget); + if( zOal ){ + sqlite3_vfs *pVfs = sqlite3_vfs_find(0); + assert( pVfs && p->rc==SQLITE_OK && p->zErrmsg==0 ); + pVfs->xDelete(pVfs, zOal, 0); + sqlite3_free(zOal); + } +} + +/* +** Allocate a private rbu VFS for the rbu handle passed as the only +** argument. This VFS will be used unless the call to sqlite3rbu_open() +** specified a URI with a vfs=? option in place of a target database +** file name. +*/ +static void rbuCreateVfs(sqlite3rbu *p){ + int rnd; + char zRnd[64]; + + assert( p->rc==SQLITE_OK ); + sqlite3_randomness(sizeof(int), (void*)&rnd); + sqlite3_snprintf(sizeof(zRnd), zRnd, "rbu_vfs_%d", rnd); + p->rc = sqlite3rbu_create_vfs(zRnd, 0); + if( p->rc==SQLITE_OK ){ + sqlite3_vfs *pVfs = sqlite3_vfs_find(zRnd); + assert( pVfs ); + p->zVfsName = pVfs->zName; + ((rbu_vfs*)pVfs)->pRbu = p; + } +} + +/* +** Destroy the private VFS created for the rbu handle passed as the only +** argument by an earlier call to rbuCreateVfs(). +*/ +static void rbuDeleteVfs(sqlite3rbu *p){ + if( p->zVfsName ){ + sqlite3rbu_destroy_vfs(p->zVfsName); + p->zVfsName = 0; + } +} + +/* +** This user-defined SQL function is invoked with a single argument - the +** name of a table expected to appear in the target database. It returns +** the number of auxilliary indexes on the table. +*/ +static void rbuIndexCntFunc( + sqlite3_context *pCtx, + int nVal, + sqlite3_value **apVal +){ + sqlite3rbu *p = (sqlite3rbu*)sqlite3_user_data(pCtx); + sqlite3_stmt *pStmt = 0; + char *zErrmsg = 0; + int rc; + sqlite3 *db = (rbuIsVacuum(p) ? p->dbRbu : p->dbMain); + + assert( nVal==1 ); + + rc = prepareFreeAndCollectError(db, &pStmt, &zErrmsg, + sqlite3_mprintf("SELECT count(*) FROM sqlite_schema " + "WHERE type='index' AND tbl_name = %Q", sqlite3_value_text(apVal[0])) + ); + if( rc!=SQLITE_OK ){ + sqlite3_result_error(pCtx, zErrmsg, -1); + }else{ + int nIndex = 0; + if( SQLITE_ROW==sqlite3_step(pStmt) ){ + nIndex = sqlite3_column_int(pStmt, 0); + } + rc = sqlite3_finalize(pStmt); + if( rc==SQLITE_OK ){ + sqlite3_result_int(pCtx, nIndex); + }else{ + sqlite3_result_error(pCtx, sqlite3_errmsg(db), -1); + } + } + + sqlite3_free(zErrmsg); +} + +/* +** If the RBU database contains the rbu_count table, use it to initialize +** the sqlite3rbu.nPhaseOneStep variable. The schema of the rbu_count table +** is assumed to contain the same columns as: +** +** CREATE TABLE rbu_count(tbl TEXT PRIMARY KEY, cnt INTEGER) WITHOUT ROWID; +** +** There should be one row in the table for each data_xxx table in the +** database. The 'tbl' column should contain the name of a data_xxx table, +** and the cnt column the number of rows it contains. +** +** sqlite3rbu.nPhaseOneStep is initialized to the sum of (1 + nIndex) * cnt +** for all rows in the rbu_count table, where nIndex is the number of +** indexes on the corresponding target database table. +*/ +static void rbuInitPhaseOneSteps(sqlite3rbu *p){ + if( p->rc==SQLITE_OK ){ + sqlite3_stmt *pStmt = 0; + int bExists = 0; /* True if rbu_count exists */ + + p->nPhaseOneStep = -1; + + p->rc = sqlite3_create_function(p->dbRbu, + "rbu_index_cnt", 1, SQLITE_UTF8, (void*)p, rbuIndexCntFunc, 0, 0 + ); + + /* Check for the rbu_count table. If it does not exist, or if an error + ** occurs, nPhaseOneStep will be left set to -1. */ + if( p->rc==SQLITE_OK ){ + p->rc = prepareAndCollectError(p->dbRbu, &pStmt, &p->zErrmsg, + "SELECT 1 FROM sqlite_schema WHERE tbl_name = 'rbu_count'" + ); + } + if( p->rc==SQLITE_OK ){ + if( SQLITE_ROW==sqlite3_step(pStmt) ){ + bExists = 1; + } + p->rc = sqlite3_finalize(pStmt); + } + + if( p->rc==SQLITE_OK && bExists ){ + p->rc = prepareAndCollectError(p->dbRbu, &pStmt, &p->zErrmsg, + "SELECT sum(cnt * (1 + rbu_index_cnt(rbu_target_name(tbl))))" + "FROM rbu_count" + ); + if( p->rc==SQLITE_OK ){ + if( SQLITE_ROW==sqlite3_step(pStmt) ){ + p->nPhaseOneStep = sqlite3_column_int64(pStmt, 0); + } + p->rc = sqlite3_finalize(pStmt); + } + } + } +} + + +static sqlite3rbu *openRbuHandle( + const char *zTarget, + const char *zRbu, + const char *zState +){ + sqlite3rbu *p; + size_t nTarget = zTarget ? strlen(zTarget) : 0; + size_t nRbu = strlen(zRbu); + size_t nByte = sizeof(sqlite3rbu) + nTarget+1 + nRbu+1; + + p = (sqlite3rbu*)sqlite3_malloc64(nByte); + if( p ){ + RbuState *pState = 0; + + /* Create the custom VFS. */ + memset(p, 0, sizeof(sqlite3rbu)); + sqlite3rbu_rename_handler(p, 0, 0); + rbuCreateVfs(p); + + /* Open the target, RBU and state databases */ + if( p->rc==SQLITE_OK ){ + char *pCsr = (char*)&p[1]; + int bRetry = 0; + if( zTarget ){ + p->zTarget = pCsr; + memcpy(p->zTarget, zTarget, nTarget+1); + pCsr += nTarget+1; + } + p->zRbu = pCsr; + memcpy(p->zRbu, zRbu, nRbu+1); + pCsr += nRbu+1; + if( zState ){ + p->zState = rbuMPrintf(p, "%s", zState); + } + + /* If the first attempt to open the database file fails and the bRetry + ** flag it set, this means that the db was not opened because it seemed + ** to be a wal-mode db. But, this may have happened due to an earlier + ** RBU vacuum operation leaving an old wal file in the directory. + ** If this is the case, it will have been checkpointed and deleted + ** when the handle was closed and a second attempt to open the + ** database may succeed. */ + rbuOpenDatabase(p, 0, &bRetry); + if( bRetry ){ + rbuOpenDatabase(p, 0, 0); + } + } + + if( p->rc==SQLITE_OK ){ + pState = rbuLoadState(p); + assert( pState || p->rc!=SQLITE_OK ); + if( p->rc==SQLITE_OK ){ + + if( pState->eStage==0 ){ + rbuDeleteOalFile(p); + rbuInitPhaseOneSteps(p); + p->eStage = RBU_STAGE_OAL; + }else{ + p->eStage = pState->eStage; + p->nPhaseOneStep = pState->nPhaseOneStep; + } + p->nProgress = pState->nProgress; + p->iOalSz = pState->iOalSz; + } + } + assert( p->rc!=SQLITE_OK || p->eStage!=0 ); + + if( p->rc==SQLITE_OK && p->pTargetFd->pWalFd ){ + if( p->eStage==RBU_STAGE_OAL ){ + p->rc = SQLITE_ERROR; + p->zErrmsg = sqlite3_mprintf("cannot update wal mode database"); + }else if( p->eStage==RBU_STAGE_MOVE ){ + p->eStage = RBU_STAGE_CKPT; + p->nStep = 0; + } + } + + if( p->rc==SQLITE_OK + && (p->eStage==RBU_STAGE_OAL || p->eStage==RBU_STAGE_MOVE) + && pState->eStage!=0 + ){ + rbu_file *pFd = (rbuIsVacuum(p) ? p->pRbuFd : p->pTargetFd); + if( pFd->iCookie!=pState->iCookie ){ + /* At this point (pTargetFd->iCookie) contains the value of the + ** change-counter cookie (the thing that gets incremented when a + ** transaction is committed in rollback mode) currently stored on + ** page 1 of the database file. */ + p->rc = SQLITE_BUSY; + p->zErrmsg = sqlite3_mprintf("database modified during rbu %s", + (rbuIsVacuum(p) ? "vacuum" : "update") + ); + } + } + + if( p->rc==SQLITE_OK ){ + if( p->eStage==RBU_STAGE_OAL ){ + sqlite3 *db = p->dbMain; + p->rc = sqlite3_exec(p->dbRbu, "BEGIN", 0, 0, &p->zErrmsg); + + /* Point the object iterator at the first object */ + if( p->rc==SQLITE_OK ){ + p->rc = rbuObjIterFirst(p, &p->objiter); + } + + /* If the RBU database contains no data_xxx tables, declare the RBU + ** update finished. */ + if( p->rc==SQLITE_OK && p->objiter.zTbl==0 ){ + p->rc = SQLITE_DONE; + p->eStage = RBU_STAGE_DONE; + }else{ + if( p->rc==SQLITE_OK && pState->eStage==0 && rbuIsVacuum(p) ){ + rbuCopyPragma(p, "page_size"); + rbuCopyPragma(p, "auto_vacuum"); + } + + /* Open transactions both databases. The *-oal file is opened or + ** created at this point. */ + if( p->rc==SQLITE_OK ){ + p->rc = sqlite3_exec(db, "BEGIN IMMEDIATE", 0, 0, &p->zErrmsg); + } + + /* Check if the main database is a zipvfs db. If it is, set the upper + ** level pager to use "journal_mode=off". This prevents it from + ** generating a large journal using a temp file. */ + if( p->rc==SQLITE_OK ){ + int frc = sqlite3_file_control(db, "main", SQLITE_FCNTL_ZIPVFS, 0); + if( frc==SQLITE_OK ){ + p->rc = sqlite3_exec( + db, "PRAGMA journal_mode=off",0,0,&p->zErrmsg); + } + } + + if( p->rc==SQLITE_OK ){ + rbuSetupOal(p, pState); + } + } + }else if( p->eStage==RBU_STAGE_MOVE ){ + /* no-op */ + }else if( p->eStage==RBU_STAGE_CKPT ){ + if( !rbuIsVacuum(p) && rbuExclusiveCheckpoint(p->dbMain) ){ + /* If the rbu_exclusive_checkpoint=1 URI parameter was specified + ** and an incremental checkpoint is being resumed, attempt an + ** exclusive lock on the db file. If this fails, so be it. */ + p->eStage = RBU_STAGE_DONE; + rbuLockDatabase(p->dbMain); + p->eStage = RBU_STAGE_CKPT; + } + rbuSetupCheckpoint(p, pState); + }else if( p->eStage==RBU_STAGE_DONE ){ + p->rc = SQLITE_DONE; + }else{ + p->rc = SQLITE_CORRUPT; + } + } + + rbuFreeState(pState); + } + + return p; +} + +/* +** Allocate and return an RBU handle with all fields zeroed except for the +** error code, which is set to SQLITE_MISUSE. +*/ +static sqlite3rbu *rbuMisuseError(void){ + sqlite3rbu *pRet; + pRet = sqlite3_malloc64(sizeof(sqlite3rbu)); + if( pRet ){ + memset(pRet, 0, sizeof(sqlite3rbu)); + pRet->rc = SQLITE_MISUSE; + } + return pRet; +} + +/* +** Open and return a new RBU handle. +*/ +sqlite3rbu *sqlite3rbu_open( + const char *zTarget, + const char *zRbu, + const char *zState +){ + if( zTarget==0 || zRbu==0 ){ return rbuMisuseError(); } + return openRbuHandle(zTarget, zRbu, zState); +} + +/* +** Open a handle to begin or resume an RBU VACUUM operation. +*/ +sqlite3rbu *sqlite3rbu_vacuum( + const char *zTarget, + const char *zState +){ + if( zTarget==0 ){ return rbuMisuseError(); } + if( zState ){ + int n = strlen(zState); + if( n>=7 && 0==memcmp("-vactmp", &zState[n-7], 7) ){ + return rbuMisuseError(); + } + } + /* TODO: Check that both arguments are non-NULL */ + return openRbuHandle(0, zTarget, zState); +} + +/* +** Return the database handle used by pRbu. +*/ +sqlite3 *sqlite3rbu_db(sqlite3rbu *pRbu, int bRbu){ + sqlite3 *db = 0; + if( pRbu ){ + db = (bRbu ? pRbu->dbRbu : pRbu->dbMain); + } + return db; +} + + +/* +** If the error code currently stored in the RBU handle is SQLITE_CONSTRAINT, +** then edit any error message string so as to remove all occurrences of +** the pattern "rbu_imp_[0-9]*". +*/ +static void rbuEditErrmsg(sqlite3rbu *p){ + if( p->rc==SQLITE_CONSTRAINT && p->zErrmsg ){ + unsigned int i; + size_t nErrmsg = strlen(p->zErrmsg); + for(i=0; i<(nErrmsg-8); i++){ + if( memcmp(&p->zErrmsg[i], "rbu_imp_", 8)==0 ){ + int nDel = 8; + while( p->zErrmsg[i+nDel]>='0' && p->zErrmsg[i+nDel]<='9' ) nDel++; + memmove(&p->zErrmsg[i], &p->zErrmsg[i+nDel], nErrmsg + 1 - i - nDel); + nErrmsg -= nDel; + } + } + } +} + +/* +** Close the RBU handle. +*/ +int sqlite3rbu_close(sqlite3rbu *p, char **pzErrmsg){ + int rc; + if( p ){ + + /* Commit the transaction to the *-oal file. */ + if( p->rc==SQLITE_OK && p->eStage==RBU_STAGE_OAL ){ + p->rc = sqlite3_exec(p->dbMain, "COMMIT", 0, 0, &p->zErrmsg); + } + + /* Sync the db file if currently doing an incremental checkpoint */ + if( p->rc==SQLITE_OK && p->eStage==RBU_STAGE_CKPT ){ + sqlite3_file *pDb = p->pTargetFd->pReal; + p->rc = pDb->pMethods->xSync(pDb, SQLITE_SYNC_NORMAL); + } + + rbuSaveState(p, p->eStage); + + if( p->rc==SQLITE_OK && p->eStage==RBU_STAGE_OAL ){ + p->rc = sqlite3_exec(p->dbRbu, "COMMIT", 0, 0, &p->zErrmsg); + } + + /* Close any open statement handles. */ + rbuObjIterFinalize(&p->objiter); + + /* If this is an RBU vacuum handle and the vacuum has either finished + ** successfully or encountered an error, delete the contents of the + ** state table. This causes the next call to sqlite3rbu_vacuum() + ** specifying the current target and state databases to start a new + ** vacuum from scratch. */ + if( rbuIsVacuum(p) && p->rc!=SQLITE_OK && p->dbRbu ){ + int rc2 = sqlite3_exec(p->dbRbu, "DELETE FROM stat.rbu_state", 0, 0, 0); + if( p->rc==SQLITE_DONE && rc2!=SQLITE_OK ) p->rc = rc2; + } + + /* Close the open database handle and VFS object. */ + sqlite3_close(p->dbRbu); + sqlite3_close(p->dbMain); + assert( p->szTemp==0 ); + rbuDeleteVfs(p); + sqlite3_free(p->aBuf); + sqlite3_free(p->aFrame); + + rbuEditErrmsg(p); + rc = p->rc; + if( pzErrmsg ){ + *pzErrmsg = p->zErrmsg; + }else{ + sqlite3_free(p->zErrmsg); + } + sqlite3_free(p->zState); + sqlite3_free(p); + }else{ + rc = SQLITE_NOMEM; + *pzErrmsg = 0; + } + return rc; +} + +/* +** Return the total number of key-value operations (inserts, deletes or +** updates) that have been performed on the target database since the +** current RBU update was started. +*/ +sqlite3_int64 sqlite3rbu_progress(sqlite3rbu *pRbu){ + return pRbu->nProgress; +} + +/* +** Return permyriadage progress indications for the two main stages of +** an RBU update. +*/ +void sqlite3rbu_bp_progress(sqlite3rbu *p, int *pnOne, int *pnTwo){ + const int MAX_PROGRESS = 10000; + switch( p->eStage ){ + case RBU_STAGE_OAL: + if( p->nPhaseOneStep>0 ){ + *pnOne = (int)(MAX_PROGRESS * (i64)p->nProgress/(i64)p->nPhaseOneStep); + }else{ + *pnOne = -1; + } + *pnTwo = 0; + break; + + case RBU_STAGE_MOVE: + *pnOne = MAX_PROGRESS; + *pnTwo = 0; + break; + + case RBU_STAGE_CKPT: + *pnOne = MAX_PROGRESS; + *pnTwo = (int)(MAX_PROGRESS * (i64)p->nStep / (i64)p->nFrame); + break; + + case RBU_STAGE_DONE: + *pnOne = MAX_PROGRESS; + *pnTwo = MAX_PROGRESS; + break; + + default: + assert( 0 ); + } +} + +/* +** Return the current state of the RBU vacuum or update operation. +*/ +int sqlite3rbu_state(sqlite3rbu *p){ + int aRes[] = { + 0, SQLITE_RBU_STATE_OAL, SQLITE_RBU_STATE_MOVE, + 0, SQLITE_RBU_STATE_CHECKPOINT, SQLITE_RBU_STATE_DONE + }; + + assert( RBU_STAGE_OAL==1 ); + assert( RBU_STAGE_MOVE==2 ); + assert( RBU_STAGE_CKPT==4 ); + assert( RBU_STAGE_DONE==5 ); + assert( aRes[RBU_STAGE_OAL]==SQLITE_RBU_STATE_OAL ); + assert( aRes[RBU_STAGE_MOVE]==SQLITE_RBU_STATE_MOVE ); + assert( aRes[RBU_STAGE_CKPT]==SQLITE_RBU_STATE_CHECKPOINT ); + assert( aRes[RBU_STAGE_DONE]==SQLITE_RBU_STATE_DONE ); + + if( p->rc!=SQLITE_OK && p->rc!=SQLITE_DONE ){ + return SQLITE_RBU_STATE_ERROR; + }else{ + assert( p->rc!=SQLITE_DONE || p->eStage==RBU_STAGE_DONE ); + assert( p->eStage==RBU_STAGE_OAL + || p->eStage==RBU_STAGE_MOVE + || p->eStage==RBU_STAGE_CKPT + || p->eStage==RBU_STAGE_DONE + ); + return aRes[p->eStage]; + } +} + +int sqlite3rbu_savestate(sqlite3rbu *p){ + int rc = p->rc; + if( rc==SQLITE_DONE ) return SQLITE_OK; + + assert( p->eStage>=RBU_STAGE_OAL && p->eStage<=RBU_STAGE_DONE ); + if( p->eStage==RBU_STAGE_OAL ){ + assert( rc!=SQLITE_DONE ); + if( rc==SQLITE_OK ) rc = sqlite3_exec(p->dbMain, "COMMIT", 0, 0, 0); + } + + /* Sync the db file */ + if( rc==SQLITE_OK && p->eStage==RBU_STAGE_CKPT ){ + sqlite3_file *pDb = p->pTargetFd->pReal; + rc = pDb->pMethods->xSync(pDb, SQLITE_SYNC_NORMAL); + } + + p->rc = rc; + rbuSaveState(p, p->eStage); + rc = p->rc; + + if( p->eStage==RBU_STAGE_OAL ){ + assert( rc!=SQLITE_DONE ); + if( rc==SQLITE_OK ) rc = sqlite3_exec(p->dbRbu, "COMMIT", 0, 0, 0); + if( rc==SQLITE_OK ){ + const char *zBegin = rbuIsVacuum(p) ? "BEGIN" : "BEGIN IMMEDIATE"; + rc = sqlite3_exec(p->dbRbu, zBegin, 0, 0, 0); + } + if( rc==SQLITE_OK ) rc = sqlite3_exec(p->dbMain, "BEGIN IMMEDIATE", 0, 0,0); + } + + p->rc = rc; + return rc; +} + +/* +** Default xRename callback for RBU. +*/ +static int xDefaultRename(void *pArg, const char *zOld, const char *zNew){ + int rc = SQLITE_OK; +#if defined(_WIN32_WCE) + { + LPWSTR zWideOld; + LPWSTR zWideNew; + + zWideOld = rbuWinUtf8ToUnicode(zOld); + if( zWideOld ){ + zWideNew = rbuWinUtf8ToUnicode(zNew); + if( zWideNew ){ + if( MoveFileW(zWideOld, zWideNew) ){ + rc = SQLITE_OK; + }else{ + rc = SQLITE_IOERR; + } + sqlite3_free(zWideNew); + }else{ + rc = SQLITE_IOERR_NOMEM; + } + sqlite3_free(zWideOld); + }else{ + rc = SQLITE_IOERR_NOMEM; + } + } +#else + rc = rename(zOld, zNew) ? SQLITE_IOERR : SQLITE_OK; +#endif + return rc; +} + +void sqlite3rbu_rename_handler( + sqlite3rbu *pRbu, + void *pArg, + int (*xRename)(void *pArg, const char *zOld, const char *zNew) +){ + if( xRename ){ + pRbu->xRename = xRename; + pRbu->pRenameArg = pArg; + }else{ + pRbu->xRename = xDefaultRename; + pRbu->pRenameArg = 0; + } +} + +/************************************************************************** +** Beginning of RBU VFS shim methods. The VFS shim modifies the behaviour +** of a standard VFS in the following ways: +** +** 1. Whenever the first page of a main database file is read or +** written, the value of the change-counter cookie is stored in +** rbu_file.iCookie. Similarly, the value of the "write-version" +** database header field is stored in rbu_file.iWriteVer. This ensures +** that the values are always trustworthy within an open transaction. +** +** 2. Whenever an SQLITE_OPEN_WAL file is opened, the (rbu_file.pWalFd) +** member variable of the associated database file descriptor is set +** to point to the new file. A mutex protected linked list of all main +** db fds opened using a particular RBU VFS is maintained at +** rbu_vfs.pMain to facilitate this. +** +** 3. Using a new file-control "SQLITE_FCNTL_RBU", a main db rbu_file +** object can be marked as the target database of an RBU update. This +** turns on the following extra special behaviour: +** +** 3a. If xAccess() is called to check if there exists a *-wal file +** associated with an RBU target database currently in RBU_STAGE_OAL +** stage (preparing the *-oal file), the following special handling +** applies: +** +** * if the *-wal file does exist, return SQLITE_CANTOPEN. An RBU +** target database may not be in wal mode already. +** +** * if the *-wal file does not exist, set the output parameter to +** non-zero (to tell SQLite that it does exist) anyway. +** +** Then, when xOpen() is called to open the *-wal file associated with +** the RBU target in RBU_STAGE_OAL stage, instead of opening the *-wal +** file, the rbu vfs opens the corresponding *-oal file instead. +** +** 3b. The *-shm pages returned by xShmMap() for a target db file in +** RBU_STAGE_OAL mode are actually stored in heap memory. This is to +** avoid creating a *-shm file on disk. Additionally, xShmLock() calls +** are no-ops on target database files in RBU_STAGE_OAL mode. This is +** because assert() statements in some VFS implementations fail if +** xShmLock() is called before xShmMap(). +** +** 3c. If an EXCLUSIVE lock is attempted on a target database file in any +** mode except RBU_STAGE_DONE (all work completed and checkpointed), it +** fails with an SQLITE_BUSY error. This is to stop RBU connections +** from automatically checkpointing a *-wal (or *-oal) file from within +** sqlite3_close(). +** +** 3d. In RBU_STAGE_CAPTURE mode, all xRead() calls on the wal file, and +** all xWrite() calls on the target database file perform no IO. +** Instead the frame and page numbers that would be read and written +** are recorded. Additionally, successful attempts to obtain exclusive +** xShmLock() WRITER, CHECKPOINTER and READ0 locks on the target +** database file are recorded. xShmLock() calls to unlock the same +** locks are no-ops (so that once obtained, these locks are never +** relinquished). Finally, calls to xSync() on the target database +** file fail with SQLITE_INTERNAL errors. +*/ + +static void rbuUnlockShm(rbu_file *p){ + assert( p->openFlags & SQLITE_OPEN_MAIN_DB ); + if( p->pRbu ){ + int (*xShmLock)(sqlite3_file*,int,int,int) = p->pReal->pMethods->xShmLock; + int i; + for(i=0; i<SQLITE_SHM_NLOCK;i++){ + if( (1<<i) & p->pRbu->mLock ){ + xShmLock(p->pReal, i, 1, SQLITE_SHM_UNLOCK|SQLITE_SHM_EXCLUSIVE); + } + } + p->pRbu->mLock = 0; + } +} + +/* +*/ +static int rbuUpdateTempSize(rbu_file *pFd, sqlite3_int64 nNew){ + sqlite3rbu *pRbu = pFd->pRbu; + i64 nDiff = nNew - pFd->sz; + pRbu->szTemp += nDiff; + pFd->sz = nNew; + assert( pRbu->szTemp>=0 ); + if( pRbu->szTempLimit && pRbu->szTemp>pRbu->szTempLimit ) return SQLITE_FULL; + return SQLITE_OK; +} + +/* +** Add an item to the main-db lists, if it is not already present. +** +** There are two main-db lists. One for all file descriptors, and one +** for all file descriptors with rbu_file.pDb!=0. If the argument has +** rbu_file.pDb!=0, then it is assumed to already be present on the +** main list and is only added to the pDb!=0 list. +*/ +static void rbuMainlistAdd(rbu_file *p){ + rbu_vfs *pRbuVfs = p->pRbuVfs; + rbu_file *pIter; + assert( (p->openFlags & SQLITE_OPEN_MAIN_DB) ); + sqlite3_mutex_enter(pRbuVfs->mutex); + if( p->pRbu==0 ){ + for(pIter=pRbuVfs->pMain; pIter; pIter=pIter->pMainNext); + p->pMainNext = pRbuVfs->pMain; + pRbuVfs->pMain = p; + }else{ + for(pIter=pRbuVfs->pMainRbu; pIter && pIter!=p; pIter=pIter->pMainRbuNext){} + if( pIter==0 ){ + p->pMainRbuNext = pRbuVfs->pMainRbu; + pRbuVfs->pMainRbu = p; + } + } + sqlite3_mutex_leave(pRbuVfs->mutex); +} + +/* +** Remove an item from the main-db lists. +*/ +static void rbuMainlistRemove(rbu_file *p){ + rbu_file **pp; + sqlite3_mutex_enter(p->pRbuVfs->mutex); + for(pp=&p->pRbuVfs->pMain; *pp && *pp!=p; pp=&((*pp)->pMainNext)){} + if( *pp ) *pp = p->pMainNext; + p->pMainNext = 0; + for(pp=&p->pRbuVfs->pMainRbu; *pp && *pp!=p; pp=&((*pp)->pMainRbuNext)){} + if( *pp ) *pp = p->pMainRbuNext; + p->pMainRbuNext = 0; + sqlite3_mutex_leave(p->pRbuVfs->mutex); +} + +/* +** Given that zWal points to a buffer containing a wal file name passed to +** either the xOpen() or xAccess() VFS method, search the main-db list for +** a file-handle opened by the same database connection on the corresponding +** database file. +** +** If parameter bRbu is true, only search for file-descriptors with +** rbu_file.pDb!=0. +*/ +static rbu_file *rbuFindMaindb(rbu_vfs *pRbuVfs, const char *zWal, int bRbu){ + rbu_file *pDb; + sqlite3_mutex_enter(pRbuVfs->mutex); + if( bRbu ){ + for(pDb=pRbuVfs->pMainRbu; pDb && pDb->zWal!=zWal; pDb=pDb->pMainRbuNext){} + }else{ + for(pDb=pRbuVfs->pMain; pDb && pDb->zWal!=zWal; pDb=pDb->pMainNext){} + } + sqlite3_mutex_leave(pRbuVfs->mutex); + return pDb; +} + +/* +** Close an rbu file. +*/ +static int rbuVfsClose(sqlite3_file *pFile){ + rbu_file *p = (rbu_file*)pFile; + int rc; + int i; + + /* Free the contents of the apShm[] array. And the array itself. */ + for(i=0; i<p->nShm; i++){ + sqlite3_free(p->apShm[i]); + } + sqlite3_free(p->apShm); + p->apShm = 0; + sqlite3_free(p->zDel); + + if( p->openFlags & SQLITE_OPEN_MAIN_DB ){ + rbuMainlistRemove(p); + rbuUnlockShm(p); + p->pReal->pMethods->xShmUnmap(p->pReal, 0); + } + else if( (p->openFlags & SQLITE_OPEN_DELETEONCLOSE) && p->pRbu ){ + rbuUpdateTempSize(p, 0); + } + assert( p->pMainNext==0 && p->pRbuVfs->pMain!=p ); + + /* Close the underlying file handle */ + rc = p->pReal->pMethods->xClose(p->pReal); + return rc; +} + + +/* +** Read and return an unsigned 32-bit big-endian integer from the buffer +** passed as the only argument. +*/ +static u32 rbuGetU32(u8 *aBuf){ + return ((u32)aBuf[0] << 24) + + ((u32)aBuf[1] << 16) + + ((u32)aBuf[2] << 8) + + ((u32)aBuf[3]); +} + +/* +** Write an unsigned 32-bit value in big-endian format to the supplied +** buffer. +*/ +static void rbuPutU32(u8 *aBuf, u32 iVal){ + aBuf[0] = (iVal >> 24) & 0xFF; + aBuf[1] = (iVal >> 16) & 0xFF; + aBuf[2] = (iVal >> 8) & 0xFF; + aBuf[3] = (iVal >> 0) & 0xFF; +} + +static void rbuPutU16(u8 *aBuf, u16 iVal){ + aBuf[0] = (iVal >> 8) & 0xFF; + aBuf[1] = (iVal >> 0) & 0xFF; +} + +/* +** Read data from an rbuVfs-file. +*/ +static int rbuVfsRead( + sqlite3_file *pFile, + void *zBuf, + int iAmt, + sqlite_int64 iOfst +){ + rbu_file *p = (rbu_file*)pFile; + sqlite3rbu *pRbu = p->pRbu; + int rc; + + if( pRbu && pRbu->eStage==RBU_STAGE_CAPTURE ){ + assert( p->openFlags & SQLITE_OPEN_WAL ); + rc = rbuCaptureWalRead(p->pRbu, iOfst, iAmt); + }else{ + if( pRbu && pRbu->eStage==RBU_STAGE_OAL + && (p->openFlags & SQLITE_OPEN_WAL) + && iOfst>=pRbu->iOalSz + ){ + rc = SQLITE_OK; + memset(zBuf, 0, iAmt); + }else{ + rc = p->pReal->pMethods->xRead(p->pReal, zBuf, iAmt, iOfst); +#if 1 + /* If this is being called to read the first page of the target + ** database as part of an rbu vacuum operation, synthesize the + ** contents of the first page if it does not yet exist. Otherwise, + ** SQLite will not check for a *-wal file. */ + if( pRbu && rbuIsVacuum(pRbu) + && rc==SQLITE_IOERR_SHORT_READ && iOfst==0 + && (p->openFlags & SQLITE_OPEN_MAIN_DB) + && pRbu->rc==SQLITE_OK + ){ + sqlite3_file *pFd = (sqlite3_file*)pRbu->pRbuFd; + rc = pFd->pMethods->xRead(pFd, zBuf, iAmt, iOfst); + if( rc==SQLITE_OK ){ + u8 *aBuf = (u8*)zBuf; + u32 iRoot = rbuGetU32(&aBuf[52]) ? 1 : 0; + rbuPutU32(&aBuf[52], iRoot); /* largest root page number */ + rbuPutU32(&aBuf[36], 0); /* number of free pages */ + rbuPutU32(&aBuf[32], 0); /* first page on free list trunk */ + rbuPutU32(&aBuf[28], 1); /* size of db file in pages */ + rbuPutU32(&aBuf[24], pRbu->pRbuFd->iCookie+1); /* Change counter */ + + if( iAmt>100 ){ + memset(&aBuf[100], 0, iAmt-100); + rbuPutU16(&aBuf[105], iAmt & 0xFFFF); + aBuf[100] = 0x0D; + } + } + } +#endif + } + if( rc==SQLITE_OK && iOfst==0 && (p->openFlags & SQLITE_OPEN_MAIN_DB) ){ + /* These look like magic numbers. But they are stable, as they are part + ** of the definition of the SQLite file format, which may not change. */ + u8 *pBuf = (u8*)zBuf; + p->iCookie = rbuGetU32(&pBuf[24]); + p->iWriteVer = pBuf[19]; + } + } + return rc; +} + +/* +** Write data to an rbuVfs-file. +*/ +static int rbuVfsWrite( + sqlite3_file *pFile, + const void *zBuf, + int iAmt, + sqlite_int64 iOfst +){ + rbu_file *p = (rbu_file*)pFile; + sqlite3rbu *pRbu = p->pRbu; + int rc; + + if( pRbu && pRbu->eStage==RBU_STAGE_CAPTURE ){ + assert( p->openFlags & SQLITE_OPEN_MAIN_DB ); + rc = rbuCaptureDbWrite(p->pRbu, iOfst); + }else{ + if( pRbu ){ + if( pRbu->eStage==RBU_STAGE_OAL + && (p->openFlags & SQLITE_OPEN_WAL) + && iOfst>=pRbu->iOalSz + ){ + pRbu->iOalSz = iAmt + iOfst; + }else if( p->openFlags & SQLITE_OPEN_DELETEONCLOSE ){ + i64 szNew = iAmt+iOfst; + if( szNew>p->sz ){ + rc = rbuUpdateTempSize(p, szNew); + if( rc!=SQLITE_OK ) return rc; + } + } + } + rc = p->pReal->pMethods->xWrite(p->pReal, zBuf, iAmt, iOfst); + if( rc==SQLITE_OK && iOfst==0 && (p->openFlags & SQLITE_OPEN_MAIN_DB) ){ + /* These look like magic numbers. But they are stable, as they are part + ** of the definition of the SQLite file format, which may not change. */ + u8 *pBuf = (u8*)zBuf; + p->iCookie = rbuGetU32(&pBuf[24]); + p->iWriteVer = pBuf[19]; + } + } + return rc; +} + +/* +** Truncate an rbuVfs-file. +*/ +static int rbuVfsTruncate(sqlite3_file *pFile, sqlite_int64 size){ + rbu_file *p = (rbu_file*)pFile; + if( (p->openFlags & SQLITE_OPEN_DELETEONCLOSE) && p->pRbu ){ + int rc = rbuUpdateTempSize(p, size); + if( rc!=SQLITE_OK ) return rc; + } + return p->pReal->pMethods->xTruncate(p->pReal, size); +} + +/* +** Sync an rbuVfs-file. +*/ +static int rbuVfsSync(sqlite3_file *pFile, int flags){ + rbu_file *p = (rbu_file *)pFile; + if( p->pRbu && p->pRbu->eStage==RBU_STAGE_CAPTURE ){ + if( p->openFlags & SQLITE_OPEN_MAIN_DB ){ + return SQLITE_INTERNAL; + } + return SQLITE_OK; + } + return p->pReal->pMethods->xSync(p->pReal, flags); +} + +/* +** Return the current file-size of an rbuVfs-file. +*/ +static int rbuVfsFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){ + rbu_file *p = (rbu_file *)pFile; + int rc; + rc = p->pReal->pMethods->xFileSize(p->pReal, pSize); + + /* If this is an RBU vacuum operation and this is the target database, + ** pretend that it has at least one page. Otherwise, SQLite will not + ** check for the existance of a *-wal file. rbuVfsRead() contains + ** similar logic. */ + if( rc==SQLITE_OK && *pSize==0 + && p->pRbu && rbuIsVacuum(p->pRbu) + && (p->openFlags & SQLITE_OPEN_MAIN_DB) + ){ + *pSize = 1024; + } + return rc; +} + +/* +** Lock an rbuVfs-file. +*/ +static int rbuVfsLock(sqlite3_file *pFile, int eLock){ + rbu_file *p = (rbu_file*)pFile; + sqlite3rbu *pRbu = p->pRbu; + int rc = SQLITE_OK; + + assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB) ); + if( eLock==SQLITE_LOCK_EXCLUSIVE + && (p->bNolock || (pRbu && pRbu->eStage!=RBU_STAGE_DONE)) + ){ + /* Do not allow EXCLUSIVE locks. Preventing SQLite from taking this + ** prevents it from checkpointing the database from sqlite3_close(). */ + rc = SQLITE_BUSY; + }else{ + rc = p->pReal->pMethods->xLock(p->pReal, eLock); + } + + return rc; +} + +/* +** Unlock an rbuVfs-file. +*/ +static int rbuVfsUnlock(sqlite3_file *pFile, int eLock){ + rbu_file *p = (rbu_file *)pFile; + return p->pReal->pMethods->xUnlock(p->pReal, eLock); +} + +/* +** Check if another file-handle holds a RESERVED lock on an rbuVfs-file. +*/ +static int rbuVfsCheckReservedLock(sqlite3_file *pFile, int *pResOut){ + rbu_file *p = (rbu_file *)pFile; + return p->pReal->pMethods->xCheckReservedLock(p->pReal, pResOut); +} + +/* +** File control method. For custom operations on an rbuVfs-file. +*/ +static int rbuVfsFileControl(sqlite3_file *pFile, int op, void *pArg){ + rbu_file *p = (rbu_file *)pFile; + int (*xControl)(sqlite3_file*,int,void*) = p->pReal->pMethods->xFileControl; + int rc; + + assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB) + || p->openFlags & (SQLITE_OPEN_TRANSIENT_DB|SQLITE_OPEN_TEMP_JOURNAL) + ); + if( op==SQLITE_FCNTL_RBU ){ + sqlite3rbu *pRbu = (sqlite3rbu*)pArg; + + /* First try to find another RBU vfs lower down in the vfs stack. If + ** one is found, this vfs will operate in pass-through mode. The lower + ** level vfs will do the special RBU handling. */ + rc = xControl(p->pReal, op, pArg); + + if( rc==SQLITE_NOTFOUND ){ + /* Now search for a zipvfs instance lower down in the VFS stack. If + ** one is found, this is an error. */ + void *dummy = 0; + rc = xControl(p->pReal, SQLITE_FCNTL_ZIPVFS, &dummy); + if( rc==SQLITE_OK ){ + rc = SQLITE_ERROR; + pRbu->zErrmsg = sqlite3_mprintf("rbu/zipvfs setup error"); + }else if( rc==SQLITE_NOTFOUND ){ + pRbu->pTargetFd = p; + p->pRbu = pRbu; + rbuMainlistAdd(p); + if( p->pWalFd ) p->pWalFd->pRbu = pRbu; + rc = SQLITE_OK; + } + } + return rc; + } + else if( op==SQLITE_FCNTL_RBUCNT ){ + sqlite3rbu *pRbu = (sqlite3rbu*)pArg; + pRbu->nRbu++; + pRbu->pRbuFd = p; + p->bNolock = 1; + } + + rc = xControl(p->pReal, op, pArg); + if( rc==SQLITE_OK && op==SQLITE_FCNTL_VFSNAME ){ + rbu_vfs *pRbuVfs = p->pRbuVfs; + char *zIn = *(char**)pArg; + char *zOut = sqlite3_mprintf("rbu(%s)/%z", pRbuVfs->base.zName, zIn); + *(char**)pArg = zOut; + if( zOut==0 ) rc = SQLITE_NOMEM; + } + + return rc; +} + +/* +** Return the sector-size in bytes for an rbuVfs-file. +*/ +static int rbuVfsSectorSize(sqlite3_file *pFile){ + rbu_file *p = (rbu_file *)pFile; + return p->pReal->pMethods->xSectorSize(p->pReal); +} + +/* +** Return the device characteristic flags supported by an rbuVfs-file. +*/ +static int rbuVfsDeviceCharacteristics(sqlite3_file *pFile){ + rbu_file *p = (rbu_file *)pFile; + return p->pReal->pMethods->xDeviceCharacteristics(p->pReal); +} + +/* +** Take or release a shared-memory lock. +*/ +static int rbuVfsShmLock(sqlite3_file *pFile, int ofst, int n, int flags){ + rbu_file *p = (rbu_file*)pFile; + sqlite3rbu *pRbu = p->pRbu; + int rc = SQLITE_OK; + +#ifdef SQLITE_AMALGAMATION + assert( WAL_CKPT_LOCK==1 ); +#endif + + assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB) ); + if( pRbu && ( + pRbu->eStage==RBU_STAGE_OAL + || pRbu->eStage==RBU_STAGE_MOVE + || pRbu->eStage==RBU_STAGE_DONE + )){ + /* Prevent SQLite from taking a shm-lock on the target file when it + ** is supplying heap memory to the upper layer in place of *-shm + ** segments. */ + if( ofst==WAL_LOCK_CKPT && n==1 ) rc = SQLITE_BUSY; + }else{ + int bCapture = 0; + if( pRbu && pRbu->eStage==RBU_STAGE_CAPTURE ){ + bCapture = 1; + } + if( bCapture==0 || 0==(flags & SQLITE_SHM_UNLOCK) ){ + rc = p->pReal->pMethods->xShmLock(p->pReal, ofst, n, flags); + if( bCapture && rc==SQLITE_OK ){ + pRbu->mLock |= ((1<<n) - 1) << ofst; + } + } + } + + return rc; +} + +/* +** Obtain a pointer to a mapping of a single 32KiB page of the *-shm file. +*/ +static int rbuVfsShmMap( + sqlite3_file *pFile, + int iRegion, + int szRegion, + int isWrite, + void volatile **pp +){ + rbu_file *p = (rbu_file*)pFile; + int rc = SQLITE_OK; + int eStage = (p->pRbu ? p->pRbu->eStage : 0); + + /* If not in RBU_STAGE_OAL, allow this call to pass through. Or, if this + ** rbu is in the RBU_STAGE_OAL state, use heap memory for *-shm space + ** instead of a file on disk. */ + assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB) ); + if( eStage==RBU_STAGE_OAL ){ + sqlite3_int64 nByte = (iRegion+1) * sizeof(char*); + char **apNew = (char**)sqlite3_realloc64(p->apShm, nByte); + + /* This is an RBU connection that uses its own heap memory for the + ** pages of the *-shm file. Since no other process can have run + ** recovery, the connection must request *-shm pages in order + ** from start to finish. */ + assert( iRegion==p->nShm ); + if( apNew==0 ){ + rc = SQLITE_NOMEM; + }else{ + memset(&apNew[p->nShm], 0, sizeof(char*) * (1 + iRegion - p->nShm)); + p->apShm = apNew; + p->nShm = iRegion+1; + } + + if( rc==SQLITE_OK ){ + char *pNew = (char*)sqlite3_malloc64(szRegion); + if( pNew==0 ){ + rc = SQLITE_NOMEM; + }else{ + memset(pNew, 0, szRegion); + p->apShm[iRegion] = pNew; + } + } + + if( rc==SQLITE_OK ){ + *pp = p->apShm[iRegion]; + }else{ + *pp = 0; + } + }else{ + assert( p->apShm==0 ); + rc = p->pReal->pMethods->xShmMap(p->pReal, iRegion, szRegion, isWrite, pp); + } + + return rc; +} + +/* +** Memory barrier. +*/ +static void rbuVfsShmBarrier(sqlite3_file *pFile){ + rbu_file *p = (rbu_file *)pFile; + p->pReal->pMethods->xShmBarrier(p->pReal); +} + +/* +** The xShmUnmap method. +*/ +static int rbuVfsShmUnmap(sqlite3_file *pFile, int delFlag){ + rbu_file *p = (rbu_file*)pFile; + int rc = SQLITE_OK; + int eStage = (p->pRbu ? p->pRbu->eStage : 0); + + assert( p->openFlags & (SQLITE_OPEN_MAIN_DB|SQLITE_OPEN_TEMP_DB) ); + if( eStage==RBU_STAGE_OAL || eStage==RBU_STAGE_MOVE ){ + /* no-op */ + }else{ + /* Release the checkpointer and writer locks */ + rbuUnlockShm(p); + rc = p->pReal->pMethods->xShmUnmap(p->pReal, delFlag); + } + return rc; +} + +/* +** Open an rbu file handle. +*/ +static int rbuVfsOpen( + sqlite3_vfs *pVfs, + const char *zName, + sqlite3_file *pFile, + int flags, + int *pOutFlags +){ + static sqlite3_io_methods rbuvfs_io_methods = { + 2, /* iVersion */ + rbuVfsClose, /* xClose */ + rbuVfsRead, /* xRead */ + rbuVfsWrite, /* xWrite */ + rbuVfsTruncate, /* xTruncate */ + rbuVfsSync, /* xSync */ + rbuVfsFileSize, /* xFileSize */ + rbuVfsLock, /* xLock */ + rbuVfsUnlock, /* xUnlock */ + rbuVfsCheckReservedLock, /* xCheckReservedLock */ + rbuVfsFileControl, /* xFileControl */ + rbuVfsSectorSize, /* xSectorSize */ + rbuVfsDeviceCharacteristics, /* xDeviceCharacteristics */ + rbuVfsShmMap, /* xShmMap */ + rbuVfsShmLock, /* xShmLock */ + rbuVfsShmBarrier, /* xShmBarrier */ + rbuVfsShmUnmap, /* xShmUnmap */ + 0, 0 /* xFetch, xUnfetch */ + }; + rbu_vfs *pRbuVfs = (rbu_vfs*)pVfs; + sqlite3_vfs *pRealVfs = pRbuVfs->pRealVfs; + rbu_file *pFd = (rbu_file *)pFile; + int rc = SQLITE_OK; + const char *zOpen = zName; + int oflags = flags; + + memset(pFd, 0, sizeof(rbu_file)); + pFd->pReal = (sqlite3_file*)&pFd[1]; + pFd->pRbuVfs = pRbuVfs; + pFd->openFlags = flags; + if( zName ){ + if( flags & SQLITE_OPEN_MAIN_DB ){ + /* A main database has just been opened. The following block sets + ** (pFd->zWal) to point to a buffer owned by SQLite that contains + ** the name of the *-wal file this db connection will use. SQLite + ** happens to pass a pointer to this buffer when using xAccess() + ** or xOpen() to operate on the *-wal file. */ + pFd->zWal = sqlite3_filename_wal(zName); + } + else if( flags & SQLITE_OPEN_WAL ){ + rbu_file *pDb = rbuFindMaindb(pRbuVfs, zName, 0); + if( pDb ){ + if( pDb->pRbu && pDb->pRbu->eStage==RBU_STAGE_OAL ){ + /* This call is to open a *-wal file. Intead, open the *-oal. */ + size_t nOpen; + if( rbuIsVacuum(pDb->pRbu) ){ + zOpen = sqlite3_db_filename(pDb->pRbu->dbRbu, "main"); + zOpen = sqlite3_filename_wal(zOpen); + } + nOpen = strlen(zOpen); + ((char*)zOpen)[nOpen-3] = 'o'; + pFd->pRbu = pDb->pRbu; + } + pDb->pWalFd = pFd; + } + } + }else{ + pFd->pRbu = pRbuVfs->pRbu; + } + + if( oflags & SQLITE_OPEN_MAIN_DB + && sqlite3_uri_boolean(zName, "rbu_memory", 0) + ){ + assert( oflags & SQLITE_OPEN_MAIN_DB ); + oflags = SQLITE_OPEN_TEMP_DB | SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE | + SQLITE_OPEN_EXCLUSIVE | SQLITE_OPEN_DELETEONCLOSE; + zOpen = 0; + } + + if( rc==SQLITE_OK ){ + rc = pRealVfs->xOpen(pRealVfs, zOpen, pFd->pReal, oflags, pOutFlags); + } + if( pFd->pReal->pMethods ){ + /* The xOpen() operation has succeeded. Set the sqlite3_file.pMethods + ** pointer and, if the file is a main database file, link it into the + ** mutex protected linked list of all such files. */ + pFile->pMethods = &rbuvfs_io_methods; + if( flags & SQLITE_OPEN_MAIN_DB ){ + rbuMainlistAdd(pFd); + } + }else{ + sqlite3_free(pFd->zDel); + } + + return rc; +} + +/* +** Delete the file located at zPath. +*/ +static int rbuVfsDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){ + sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs; + return pRealVfs->xDelete(pRealVfs, zPath, dirSync); +} + +/* +** Test for access permissions. Return true if the requested permission +** is available, or false otherwise. +*/ +static int rbuVfsAccess( + sqlite3_vfs *pVfs, + const char *zPath, + int flags, + int *pResOut +){ + rbu_vfs *pRbuVfs = (rbu_vfs*)pVfs; + sqlite3_vfs *pRealVfs = pRbuVfs->pRealVfs; + int rc; + + rc = pRealVfs->xAccess(pRealVfs, zPath, flags, pResOut); + + /* If this call is to check if a *-wal file associated with an RBU target + ** database connection exists, and the RBU update is in RBU_STAGE_OAL, + ** the following special handling is activated: + ** + ** a) if the *-wal file does exist, return SQLITE_CANTOPEN. This + ** ensures that the RBU extension never tries to update a database + ** in wal mode, even if the first page of the database file has + ** been damaged. + ** + ** b) if the *-wal file does not exist, claim that it does anyway, + ** causing SQLite to call xOpen() to open it. This call will also + ** be intercepted (see the rbuVfsOpen() function) and the *-oal + ** file opened instead. + */ + if( rc==SQLITE_OK && flags==SQLITE_ACCESS_EXISTS ){ + rbu_file *pDb = rbuFindMaindb(pRbuVfs, zPath, 1); + if( pDb && pDb->pRbu->eStage==RBU_STAGE_OAL ){ + assert( pDb->pRbu ); + if( *pResOut ){ + rc = SQLITE_CANTOPEN; + }else{ + sqlite3_int64 sz = 0; + rc = rbuVfsFileSize(&pDb->base, &sz); + *pResOut = (sz>0); + } + } + } + + return rc; +} + +/* +** Populate buffer zOut with the full canonical pathname corresponding +** to the pathname in zPath. zOut is guaranteed to point to a buffer +** of at least (DEVSYM_MAX_PATHNAME+1) bytes. +*/ +static int rbuVfsFullPathname( + sqlite3_vfs *pVfs, + const char *zPath, + int nOut, + char *zOut +){ + sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs; + return pRealVfs->xFullPathname(pRealVfs, zPath, nOut, zOut); +} + +#ifndef SQLITE_OMIT_LOAD_EXTENSION +/* +** Open the dynamic library located at zPath and return a handle. +*/ +static void *rbuVfsDlOpen(sqlite3_vfs *pVfs, const char *zPath){ + sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs; + return pRealVfs->xDlOpen(pRealVfs, zPath); +} + +/* +** Populate the buffer zErrMsg (size nByte bytes) with a human readable +** utf-8 string describing the most recent error encountered associated +** with dynamic libraries. +*/ +static void rbuVfsDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){ + sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs; + pRealVfs->xDlError(pRealVfs, nByte, zErrMsg); +} + +/* +** Return a pointer to the symbol zSymbol in the dynamic library pHandle. +*/ +static void (*rbuVfsDlSym( + sqlite3_vfs *pVfs, + void *pArg, + const char *zSym +))(void){ + sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs; + return pRealVfs->xDlSym(pRealVfs, pArg, zSym); +} + +/* +** Close the dynamic library handle pHandle. +*/ +static void rbuVfsDlClose(sqlite3_vfs *pVfs, void *pHandle){ + sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs; + pRealVfs->xDlClose(pRealVfs, pHandle); +} +#endif /* SQLITE_OMIT_LOAD_EXTENSION */ + +/* +** Populate the buffer pointed to by zBufOut with nByte bytes of +** random data. +*/ +static int rbuVfsRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){ + sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs; + return pRealVfs->xRandomness(pRealVfs, nByte, zBufOut); +} + +/* +** Sleep for nMicro microseconds. Return the number of microseconds +** actually slept. +*/ +static int rbuVfsSleep(sqlite3_vfs *pVfs, int nMicro){ + sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs; + return pRealVfs->xSleep(pRealVfs, nMicro); +} + +/* +** Return the current time as a Julian Day number in *pTimeOut. +*/ +static int rbuVfsCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){ + sqlite3_vfs *pRealVfs = ((rbu_vfs*)pVfs)->pRealVfs; + return pRealVfs->xCurrentTime(pRealVfs, pTimeOut); +} + +/* +** No-op. +*/ +static int rbuVfsGetLastError(sqlite3_vfs *pVfs, int a, char *b){ + return 0; +} + +/* +** Deregister and destroy an RBU vfs created by an earlier call to +** sqlite3rbu_create_vfs(). +*/ +void sqlite3rbu_destroy_vfs(const char *zName){ + sqlite3_vfs *pVfs = sqlite3_vfs_find(zName); + if( pVfs && pVfs->xOpen==rbuVfsOpen ){ + sqlite3_mutex_free(((rbu_vfs*)pVfs)->mutex); + sqlite3_vfs_unregister(pVfs); + sqlite3_free(pVfs); + } +} + +/* +** Create an RBU VFS named zName that accesses the underlying file-system +** via existing VFS zParent. The new object is registered as a non-default +** VFS with SQLite before returning. +*/ +int sqlite3rbu_create_vfs(const char *zName, const char *zParent){ + + /* Template for VFS */ + static sqlite3_vfs vfs_template = { + 1, /* iVersion */ + 0, /* szOsFile */ + 0, /* mxPathname */ + 0, /* pNext */ + 0, /* zName */ + 0, /* pAppData */ + rbuVfsOpen, /* xOpen */ + rbuVfsDelete, /* xDelete */ + rbuVfsAccess, /* xAccess */ + rbuVfsFullPathname, /* xFullPathname */ + +#ifndef SQLITE_OMIT_LOAD_EXTENSION + rbuVfsDlOpen, /* xDlOpen */ + rbuVfsDlError, /* xDlError */ + rbuVfsDlSym, /* xDlSym */ + rbuVfsDlClose, /* xDlClose */ +#else + 0, 0, 0, 0, +#endif + + rbuVfsRandomness, /* xRandomness */ + rbuVfsSleep, /* xSleep */ + rbuVfsCurrentTime, /* xCurrentTime */ + rbuVfsGetLastError, /* xGetLastError */ + 0, /* xCurrentTimeInt64 (version 2) */ + 0, 0, 0 /* Unimplemented version 3 methods */ + }; + + rbu_vfs *pNew = 0; /* Newly allocated VFS */ + int rc = SQLITE_OK; + size_t nName; + size_t nByte; + + nName = strlen(zName); + nByte = sizeof(rbu_vfs) + nName + 1; + pNew = (rbu_vfs*)sqlite3_malloc64(nByte); + if( pNew==0 ){ + rc = SQLITE_NOMEM; + }else{ + sqlite3_vfs *pParent; /* Parent VFS */ + memset(pNew, 0, nByte); + pParent = sqlite3_vfs_find(zParent); + if( pParent==0 ){ + rc = SQLITE_NOTFOUND; + }else{ + char *zSpace; + memcpy(&pNew->base, &vfs_template, sizeof(sqlite3_vfs)); + pNew->base.mxPathname = pParent->mxPathname; + pNew->base.szOsFile = sizeof(rbu_file) + pParent->szOsFile; + pNew->pRealVfs = pParent; + pNew->base.zName = (const char*)(zSpace = (char*)&pNew[1]); + memcpy(zSpace, zName, nName); + + /* Allocate the mutex and register the new VFS (not as the default) */ + pNew->mutex = sqlite3_mutex_alloc(SQLITE_MUTEX_RECURSIVE); + if( pNew->mutex==0 ){ + rc = SQLITE_NOMEM; + }else{ + rc = sqlite3_vfs_register(&pNew->base, 0); + } + } + + if( rc!=SQLITE_OK ){ + sqlite3_mutex_free(pNew->mutex); + sqlite3_free(pNew); + } + } + + return rc; +} + +/* +** Configure the aggregate temp file size limit for this RBU handle. +*/ +sqlite3_int64 sqlite3rbu_temp_size_limit(sqlite3rbu *pRbu, sqlite3_int64 n){ + if( n>=0 ){ + pRbu->szTempLimit = n; + } + return pRbu->szTempLimit; +} + +sqlite3_int64 sqlite3rbu_temp_size(sqlite3rbu *pRbu){ + return pRbu->szTemp; +} + + +/**************************************************************************/ + +#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_RBU) */ |