/*
** This routine implements the OP_Vacuum opcode of the VDBE.
*/
int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
int rc = SQLITE_OK; /* Return code from service routines */
const char *zFilename; /* full pathname of the database file */
int nFilename; /* number of characters in zFilename[] */
char *zTemp = 0; /* a temporary file in same directory as zFilename */
Btree *pMain; /* The database being vacuumed */
Btree *pTemp;
char *zSql = 0;
int saved_flags; /* Saved value of the db->flags */
Db *pDb = 0; /* Database to detach at end of vacuum */
/* Save the current value of the write-schema flag before setting it. */
saved_flags = db->flags;
db->flags |= SQLITE_WriteSchema | SQLITE_IgnoreChecks;
if( !db->autoCommit ){
sqlite3SetString(pzErrMsg, "cannot VACUUM from within a transaction",
(char*)0);
rc = SQLITE_ERROR;
goto end_of_vacuum;
}
/* Get the full pathname of the database file and create a
** temporary filename in the same directory as the original file.
*/
pMain = db->aDb[0].pBt;
zFilename = sqlite3BtreeGetFilename(pMain);
assert( zFilename );
if( zFilename[0]=='\0' ){
/* The in-memory database. Do nothing. Return directly to avoid causing
** an error trying to DETACH the vacuum_db (which never got attached)
** in the exit-handler.
*/
return SQLITE_OK;
}
nFilename = strlen(zFilename);
zTemp = sqliteMalloc( nFilename+100 );
if( zTemp==0 ){
rc = SQLITE_NOMEM;
goto end_of_vacuum;
}
strcpy(zTemp, zFilename);
/* The randomName() procedure in the following loop uses an excellent
** source of randomness to generate a name from a space of 1.3e+31
** possibilities. So unless the directory already contains on the order
** of 1.3e+31 files, the probability that the following loop will
** run more than once or twice is vanishingly small. We are certain
** enough that this loop will always terminate (and terminate quickly)
** that we don't even bother to set a maximum loop count.
*/
do {
zTemp[nFilename] = '-';
randomName((unsigned char*)&zTemp[nFilename+1]);
} while( sqlite3OsFileExists(zTemp) );
/* Attach the temporary database as 'vacuum_db'. The synchronous pragma
** can be set to 'off' for this file, as it is not recovered if a crash
** occurs anyway. The integrity of the database is maintained by a
** (possibly synchronous) transaction opened on the main database before
** sqlite3BtreeCopyFile() is called.
**
** An optimisation would be to use a non-journaled pager.
*/
zSql = sqlite3MPrintf("ATTACH '%q' AS vacuum_db;", zTemp);
if( !zSql ){
rc = SQLITE_NOMEM;
goto end_of_vacuum;
}
rc = execSql(db, zSql);
sqliteFree(zSql);
zSql = 0;
if( rc!=SQLITE_OK ) goto end_of_vacuum;
pDb = &db->aDb[db->nDb-1];
assert( strcmp(db->aDb[db->nDb-1].zName,"vacuum_db")==0 );
pTemp = db->aDb[db->nDb-1].pBt;
sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain),
sqlite3BtreeGetReserve(pMain));
assert( sqlite3BtreeGetPageSize(pTemp)==sqlite3BtreeGetPageSize(pMain) );
rc = execSql(db, "PRAGMA vacuum_db.synchronous=OFF");
if( rc!=SQLITE_OK ){
goto end_of_vacuum;
}
#ifndef SQLITE_OMIT_AUTOVACUUM
sqlite3BtreeSetAutoVacuum(pTemp, sqlite3BtreeGetAutoVacuum(pMain));
#endif
/* Begin a transaction */
rc = execSql(db, "BEGIN EXCLUSIVE;");
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Query the schema of the main database. Create a mirror schema
** in the temporary database.
*/
rc = execExecSql(db,
"SELECT 'CREATE TABLE vacuum_db.' || substr(sql,14,100000000) "
" FROM sqlite_master WHERE type='table' AND name!='sqlite_sequence'"
" AND rootpage>0"
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = execExecSql(db,
"SELECT 'CREATE INDEX vacuum_db.' || substr(sql,14,100000000)"
" FROM sqlite_master WHERE sql LIKE 'CREATE INDEX %' ");
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = execExecSql(db,
"SELECT 'CREATE UNIQUE INDEX vacuum_db.' || substr(sql,21,100000000) "
" FROM sqlite_master WHERE sql LIKE 'CREATE UNIQUE INDEX %'");
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Loop through the tables in the main database. For each, do
** an "INSERT INTO vacuum_db.xxx SELECT * FROM xxx;" to copy
** the contents to the temporary database.
*/
rc = execExecSql(db,
"SELECT 'INSERT INTO vacuum_db.' || quote(name) "
"|| ' SELECT * FROM ' || quote(name) || ';'"
"FROM sqlite_master "
"WHERE type = 'table' AND name!='sqlite_sequence' "
" AND rootpage>0"
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Copy over the sequence table
*/
rc = execExecSql(db,
"SELECT 'DELETE FROM vacuum_db.' || quote(name) || ';' "
"FROM vacuum_db.sqlite_master WHERE name='sqlite_sequence' "
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = execExecSql(db,
"SELECT 'INSERT INTO vacuum_db.' || quote(name) "
"|| ' SELECT * FROM ' || quote(name) || ';' "
"FROM vacuum_db.sqlite_master WHERE name=='sqlite_sequence';"
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Copy the triggers, views, and virtual tables from the main database
** over to the temporary database. None of these objects has any
** associated storage, so all we have to do is copy their entries
** from the SQLITE_MASTER table.
*/
rc = execSql(db,
"INSERT INTO vacuum_db.sqlite_master "
" SELECT type, name, tbl_name, rootpage, sql"
" FROM sqlite_master"
" WHERE type='view' OR type='trigger'"
" OR (type='table' AND rootpage=0)"
);
if( rc ) goto end_of_vacuum;
/* At this point, unless the main db was completely empty, there is now a
** transaction open on the vacuum database, but not on the main database.
** Open a btree level transaction on the main database. This allows a
** call to sqlite3BtreeCopyFile(). The main database btree level
** transaction is then committed, so the SQL level never knows it was
** opened for writing. This way, the SQL transaction used to create the
** temporary database never needs to be committed.
*/
if( rc==SQLITE_OK ){
u32 meta;
int i;
/* This array determines which meta meta values are preserved in the
** vacuum. Even entries are the meta value number and odd entries
** are an increment to apply to the meta value after the vacuum.
** The increment is used to increase the schema cookie so that other
** connections to the same database will know to reread the schema.
*/
static const unsigned char aCopy[] = {
1, 1, /* Add one to the old schema cookie */
3, 0, /* Preserve the default page cache size */
5, 0, /* Preserve the default text encoding */
6, 0, /* Preserve the user version */
};
assert( 1==sqlite3BtreeIsInTrans(pTemp) );
assert( 1==sqlite3BtreeIsInTrans(pMain) );
/* Copy Btree meta values */
for(i=0; i<sizeof(aCopy)/sizeof(aCopy[0]); i+=2){
rc = sqlite3BtreeGetMeta(pMain, aCopy[i], &meta);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeUpdateMeta(pTemp, aCopy[i], meta+aCopy[i+1]);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
}
rc = sqlite3BtreeCopyFile(pMain, pTemp);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeCommit(pTemp);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeCommit(pMain);
}
end_of_vacuum:
/* Restore the original value of db->flags */
db->flags = saved_flags;
/* Currently there is an SQL level transaction open on the vacuum
** database. No locks are held on any other files (since the main file
** was committed at the btree level). So it safe to end the transaction
** by manually setting the autoCommit flag to true and detaching the
** vacuum database. The vacuum_db journal file is deleted when the pager
** is closed by the DETACH.
*/
db->autoCommit = 1;
if( pDb ){
sqlite3MallocDisallow();
sqlite3BtreeClose(pDb->pBt);
sqlite3MallocAllow();
pDb->pBt = 0;
pDb->pSchema = 0;
}
if( zTemp ){
sqlite3OsDelete(zTemp);
sqliteFree(zTemp);
}
sqliteFree( zSql );
sqlite3ResetInternalSchema(db, 0);
return rc;
}
/*
** This routine implements the OP_Vacuum opcode of the VDBE.
*/
int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
int rc = SQLITE_OK; /* Return code from service routines */
Btree *pMain; /* The database being vacuumed */
Pager *pMainPager; /* Pager for database being vacuumed */
Btree *pTemp; /* The temporary database we vacuum into */
char *zSql = 0; /* SQL statements */
int saved_flags; /* Saved value of the db->flags */
int saved_nChange; /* Saved value of db->nChange */
int saved_nTotalChange; /* Saved value of db->nTotalChange */
Db *pDb = 0; /* Database to detach at end of vacuum */
int isMemDb; /* True is vacuuming a :memory: database */
int nRes;
/* Save the current value of the write-schema flag before setting it. */
saved_flags = db->flags;
saved_nChange = db->nChange;
saved_nTotalChange = db->nTotalChange;
db->flags |= SQLITE_WriteSchema | SQLITE_IgnoreChecks;
if( !db->autoCommit ){
sqlite3SetString(pzErrMsg, db, "cannot VACUUM from within a transaction");
rc = SQLITE_ERROR;
goto end_of_vacuum;
}
pMain = db->aDb[0].pBt;
pMainPager = sqlite3BtreePager(pMain);
isMemDb = sqlite3PagerFile(pMainPager)->pMethods==0;
/* Attach the temporary database as 'vacuum_db'. The synchronous pragma
** can be set to 'off' for this file, as it is not recovered if a crash
** occurs anyway. The integrity of the database is maintained by a
** (possibly synchronous) transaction opened on the main database before
** sqlite3BtreeCopyFile() is called.
**
** An optimisation would be to use a non-journaled pager.
** (Later:) I tried setting "PRAGMA vacuum_db.journal_mode=OFF" but
** that actually made the VACUUM run slower. Very little journalling
** actually occurs when doing a vacuum since the vacuum_db is initially
** empty. Only the journal header is written. Apparently it takes more
** time to parse and run the PRAGMA to turn journalling off than it does
** to write the journal header file.
*/
zSql = "ATTACH '' AS vacuum_db;";
rc = execSql(db, zSql);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
pDb = &db->aDb[db->nDb-1];
assert( strcmp(db->aDb[db->nDb-1].zName,"vacuum_db")==0 );
pTemp = db->aDb[db->nDb-1].pBt;
nRes = sqlite3BtreeGetReserve(pMain);
/* A VACUUM cannot change the pagesize of an encrypted database. */
#ifdef SQLITE_HAS_CODEC
if( db->nextPagesize ){
extern void sqlite3CodecGetKey(sqlite3*, int, void**, int*);
int nKey;
char *zKey;
sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
if( nKey ) db->nextPagesize = 0;
}
#endif
if( sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain), nRes)
|| (!isMemDb && sqlite3BtreeSetPageSize(pTemp, db->nextPagesize, nRes))
|| db->mallocFailed
){
rc = SQLITE_NOMEM;
goto end_of_vacuum;
}
rc = execSql(db, "PRAGMA vacuum_db.synchronous=OFF");
if( rc!=SQLITE_OK ){
goto end_of_vacuum;
}
#ifndef SQLITE_OMIT_AUTOVACUUM
sqlite3BtreeSetAutoVacuum(pTemp, db->nextAutovac>=0 ? db->nextAutovac :
sqlite3BtreeGetAutoVacuum(pMain));
#endif
/* Begin a transaction */
rc = execSql(db, "BEGIN EXCLUSIVE;");
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Query the schema of the main database. Create a mirror schema
** in the temporary database.
*/
rc = execExecSql(db,
"SELECT 'CREATE TABLE vacuum_db.' || substr(sql,14) "
" FROM sqlite_master WHERE type='table' AND name!='sqlite_sequence'"
" AND rootpage>0"
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = execExecSql(db,
"SELECT 'CREATE INDEX vacuum_db.' || substr(sql,14)"
" FROM sqlite_master WHERE sql LIKE 'CREATE INDEX %' ");
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = execExecSql(db,
"SELECT 'CREATE UNIQUE INDEX vacuum_db.' || substr(sql,21) "
" FROM sqlite_master WHERE sql LIKE 'CREATE UNIQUE INDEX %'");
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Loop through the tables in the main database. For each, do
** an "INSERT INTO vacuum_db.xxx SELECT * FROM xxx;" to copy
** the contents to the temporary database.
*/
rc = execExecSql(db,
"SELECT 'INSERT INTO vacuum_db.' || quote(name) "
"|| ' SELECT * FROM ' || quote(name) || ';'"
"FROM sqlite_master "
"WHERE type = 'table' AND name!='sqlite_sequence' "
" AND rootpage>0"
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Copy over the sequence table
*/
rc = execExecSql(db,
"SELECT 'DELETE FROM vacuum_db.' || quote(name) || ';' "
"FROM vacuum_db.sqlite_master WHERE name='sqlite_sequence' "
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = execExecSql(db,
"SELECT 'INSERT INTO vacuum_db.' || quote(name) "
"|| ' SELECT * FROM ' || quote(name) || ';' "
"FROM vacuum_db.sqlite_master WHERE name=='sqlite_sequence';"
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Copy the triggers, views, and virtual tables from the main database
** over to the temporary database. None of these objects has any
** associated storage, so all we have to do is copy their entries
** from the SQLITE_MASTER table.
*/
rc = execSql(db,
"INSERT INTO vacuum_db.sqlite_master "
" SELECT type, name, tbl_name, rootpage, sql"
" FROM sqlite_master"
" WHERE type='view' OR type='trigger'"
" OR (type='table' AND rootpage=0)"
);
if( rc ) goto end_of_vacuum;
/* At this point, unless the main db was completely empty, there is now a
** transaction open on the vacuum database, but not on the main database.
** Open a btree level transaction on the main database. This allows a
** call to sqlite3BtreeCopyFile(). The main database btree level
** transaction is then committed, so the SQL level never knows it was
** opened for writing. This way, the SQL transaction used to create the
** temporary database never needs to be committed.
*/
if( rc==SQLITE_OK ){
u32 meta;
int i;
/* This array determines which meta meta values are preserved in the
** vacuum. Even entries are the meta value number and odd entries
** are an increment to apply to the meta value after the vacuum.
** The increment is used to increase the schema cookie so that other
** connections to the same database will know to reread the schema.
*/
static const unsigned char aCopy[] = {
1, 1, /* Add one to the old schema cookie */
3, 0, /* Preserve the default page cache size */
5, 0, /* Preserve the default text encoding */
6, 0, /* Preserve the user version */
};
assert( 1==sqlite3BtreeIsInTrans(pTemp) );
assert( 1==sqlite3BtreeIsInTrans(pMain) );
/* Copy Btree meta values */
for(i=0; i<ArraySize(aCopy); i+=2){
rc = sqlite3BtreeGetMeta(pMain, aCopy[i], &meta);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeUpdateMeta(pTemp, aCopy[i], meta+aCopy[i+1]);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
}
rc = sqlite3BtreeCopyFile(pMain, pTemp);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeCommit(pTemp);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
#ifndef SQLITE_OMIT_AUTOVACUUM
sqlite3BtreeSetAutoVacuum(pMain, sqlite3BtreeGetAutoVacuum(pTemp));
#endif
rc = sqlite3BtreeCommit(pMain);
}
if( rc==SQLITE_OK ){
rc = sqlite3BtreeSetPageSize(pMain, sqlite3BtreeGetPageSize(pTemp), nRes);
}
end_of_vacuum:
/* Restore the original value of db->flags */
db->flags = saved_flags;
db->nChange = saved_nChange;
db->nTotalChange = saved_nTotalChange;
/* Currently there is an SQL level transaction open on the vacuum
** database. No locks are held on any other files (since the main file
** was committed at the btree level). So it safe to end the transaction
** by manually setting the autoCommit flag to true and detaching the
** vacuum database. The vacuum_db journal file is deleted when the pager
** is closed by the DETACH.
*/
db->autoCommit = 1;
if( pDb ){
sqlite3BtreeClose(pDb->pBt);
pDb->pBt = 0;
pDb->pSchema = 0;
}
sqlite3ResetInternalSchema(db, 0);
return rc;
}
int sqlcipher_codec_ctx_migrate(codec_ctx *ctx) {
u32 meta;
int rc = 0;
int command_idx = 0;
int password_sz;
int saved_flags;
int saved_nChange;
int saved_nTotalChange;
void (*saved_xTrace)(void*,const char*);
Db *pDb = 0;
sqlite3 *db = ctx->pBt->db;
const char *db_filename = sqlite3_db_filename(db, "main");
char *migrated_db_filename = sqlite3_mprintf("%s-migrated", db_filename);
char *pragma_hmac_off = "PRAGMA cipher_use_hmac = OFF;";
char *pragma_4k_kdf_iter = "PRAGMA kdf_iter = 4000;";
char *pragma_1x_and_4k;
char *set_user_version;
char *key;
int key_sz;
int user_version = 0;
int upgrade_1x_format = 0;
int upgrade_4k_format = 0;
static const unsigned char aCopy[] = {
BTREE_SCHEMA_VERSION, 1, /* Add one to the old schema cookie */
BTREE_DEFAULT_CACHE_SIZE, 0, /* Preserve the default page cache size */
BTREE_TEXT_ENCODING, 0, /* Preserve the text encoding */
BTREE_USER_VERSION, 0, /* Preserve the user version */
BTREE_APPLICATION_ID, 0, /* Preserve the application id */
};
key_sz = ctx->read_ctx->pass_sz + 1;
key = sqlcipher_malloc(key_sz);
memset(key, 0, key_sz);
memcpy(key, ctx->read_ctx->pass, ctx->read_ctx->pass_sz);
if(db_filename){
const char* commands[5];
char *attach_command = sqlite3_mprintf("ATTACH DATABASE '%s-migrated' as migrate KEY '%q';",
db_filename, key);
int rc = sqlcipher_check_connection(db_filename, key, ctx->read_ctx->pass_sz, "", &user_version);
if(rc == SQLITE_OK){
CODEC_TRACE(("No upgrade required - exiting\n"));
goto exit;
}
// Version 2 - check for 4k with hmac format
rc = sqlcipher_check_connection(db_filename, key, ctx->read_ctx->pass_sz, pragma_4k_kdf_iter, &user_version);
if(rc == SQLITE_OK) {
CODEC_TRACE(("Version 2 format found\n"));
upgrade_4k_format = 1;
}
// Version 1 - check both no hmac and 4k together
pragma_1x_and_4k = sqlite3_mprintf("%s%s", pragma_hmac_off,
pragma_4k_kdf_iter);
rc = sqlcipher_check_connection(db_filename, key, ctx->read_ctx->pass_sz, pragma_1x_and_4k, &user_version);
sqlite3_free(pragma_1x_and_4k);
if(rc == SQLITE_OK) {
CODEC_TRACE(("Version 1 format found\n"));
upgrade_1x_format = 1;
upgrade_4k_format = 1;
}
if(upgrade_1x_format == 0 && upgrade_4k_format == 0) {
CODEC_TRACE(("Upgrade format not determined\n"));
goto handle_error;
}
set_user_version = sqlite3_mprintf("PRAGMA migrate.user_version = %d;", user_version);
commands[0] = upgrade_4k_format == 1 ? pragma_4k_kdf_iter : "";
commands[1] = upgrade_1x_format == 1 ? pragma_hmac_off : "";
commands[2] = attach_command;
commands[3] = "SELECT sqlcipher_export('migrate');";
commands[4] = set_user_version;
for(command_idx = 0; command_idx < ArraySize(commands); command_idx++){
const char *command = commands[command_idx];
if(strcmp(command, "") == 0){
continue;
}
rc = sqlite3_exec(db, command, NULL, NULL, NULL);
if(rc != SQLITE_OK){
break;
}
}
sqlite3_free(attach_command);
sqlite3_free(set_user_version);
sqlcipher_free(key, key_sz);
if(rc == SQLITE_OK){
Btree *pDest;
Btree *pSrc;
int i = 0;
if( !db->autoCommit ){
CODEC_TRACE(("cannot migrate from within a transaction"));
goto handle_error;
}
if( db->nVdbeActive>1 ){
CODEC_TRACE(("cannot migrate - SQL statements in progress"));
goto handle_error;
}
/* Save the current value of the database flags so that it can be
** restored before returning. Then set the writable-schema flag, and
** disable CHECK and foreign key constraints. */
saved_flags = db->flags;
saved_nChange = db->nChange;
saved_nTotalChange = db->nTotalChange;
saved_xTrace = db->xTrace;
db->flags |= SQLITE_WriteSchema | SQLITE_IgnoreChecks | SQLITE_PreferBuiltin;
db->flags &= ~(SQLITE_ForeignKeys | SQLITE_ReverseOrder);
db->xTrace = 0;
pDest = db->aDb[0].pBt;
pDb = &(db->aDb[db->nDb-1]);
pSrc = pDb->pBt;
rc = sqlite3_exec(db, "BEGIN;", NULL, NULL, NULL);
rc = sqlite3BtreeBeginTrans(pSrc, 2);
rc = sqlite3BtreeBeginTrans(pDest, 2);
assert( 1==sqlite3BtreeIsInTrans(pDest) );
assert( 1==sqlite3BtreeIsInTrans(pSrc) );
sqlite3CodecGetKey(db, db->nDb - 1, (void**)&key, &password_sz);
sqlite3CodecAttach(db, 0, key, password_sz);
sqlite3pager_get_codec(pDest->pBt->pPager, (void**)&ctx);
ctx->skip_read_hmac = 1;
for(i=0; i<ArraySize(aCopy); i+=2){
sqlite3BtreeGetMeta(pSrc, aCopy[i], &meta);
rc = sqlite3BtreeUpdateMeta(pDest, aCopy[i], meta+aCopy[i+1]);
if( NEVER(rc!=SQLITE_OK) ) goto handle_error;
}
rc = sqlite3BtreeCopyFile(pDest, pSrc);
ctx->skip_read_hmac = 0;
if( rc!=SQLITE_OK ) goto handle_error;
rc = sqlite3BtreeCommit(pDest);
db->flags = saved_flags;
db->nChange = saved_nChange;
db->nTotalChange = saved_nTotalChange;
db->xTrace = saved_xTrace;
db->autoCommit = 1;
if( pDb ){
sqlite3BtreeClose(pDb->pBt);
pDb->pBt = 0;
pDb->pSchema = 0;
}
sqlite3ResetAllSchemasOfConnection(db);
remove(migrated_db_filename);
sqlite3_free(migrated_db_filename);
} else {
CODEC_TRACE(("*** migration failure** \n\n"));
}
}
goto exit;
handle_error:
CODEC_TRACE(("An error occurred attempting to migrate the database\n"));
rc = SQLITE_ERROR;
exit:
return rc;
}
/* CHANGE 1 of 3: Add function parameter nRes */
SQLITE_PRIVATE int sqlite3RunVacuumForRekey(char **pzErrMsg, sqlite3 *db, int iDb, int nRes){
int rc = SQLITE_OK; /* Return code from service routines */
Btree *pMain; /* The database being vacuumed */
Btree *pTemp; /* The temporary database we vacuum into */
u16 saved_mDbFlags; /* Saved value of db->mDbFlags */
u32 saved_flags; /* Saved value of db->flags */
int saved_nChange; /* Saved value of db->nChange */
int saved_nTotalChange; /* Saved value of db->nTotalChange */
u8 saved_mTrace; /* Saved trace settings */
Db *pDb = 0; /* Database to detach at end of vacuum */
int isMemDb; /* True if vacuuming a :memory: database */
/* CHANGE 2 of 3: Do not define local variable nRes */
/*int nRes;*/ /* Bytes of reserved space at the end of each page */
int nDb; /* Number of attached databases */
const char *zDbMain; /* Schema name of database to vacuum */
if (!db->autoCommit) {
sqlite3SetString(pzErrMsg, db, "cannot VACUUM from within a transaction");
return SQLITE_ERROR;
}
if (db->nVdbeActive>1) {
sqlite3SetString(pzErrMsg, db, "cannot VACUUM - SQL statements in progress");
return SQLITE_ERROR;
}
/* Save the current value of the database flags so that it can be
** restored before returning. Then set the writable-schema flag, and
** disable CHECK and foreign key constraints. */
saved_flags = db->flags;
saved_mDbFlags = db->mDbFlags;
saved_nChange = db->nChange;
saved_nTotalChange = db->nTotalChange;
saved_mTrace = db->mTrace;
db->flags |= SQLITE_WriteSchema | SQLITE_IgnoreChecks;
db->mDbFlags |= DBFLAG_PreferBuiltin | DBFLAG_Vacuum;
db->flags &= ~(SQLITE_ForeignKeys | SQLITE_ReverseOrder | SQLITE_CountRows);
db->mTrace = 0;
zDbMain = db->aDb[iDb].zDbSName;
pMain = db->aDb[iDb].pBt;
isMemDb = sqlite3PagerIsMemdb(sqlite3BtreePager(pMain));
/* Attach the temporary database as 'vacuum_db'. The synchronous pragma
** can be set to 'off' for this file, as it is not recovered if a crash
** occurs anyway. The integrity of the database is maintained by a
** (possibly synchronous) transaction opened on the main database before
** sqlite3BtreeCopyFile() is called.
**
** An optimisation would be to use a non-journaled pager.
** (Later:) I tried setting "PRAGMA vacuum_db.journal_mode=OFF" but
** that actually made the VACUUM run slower. Very little journalling
** actually occurs when doing a vacuum since the vacuum_db is initially
** empty. Only the journal header is written. Apparently it takes more
** time to parse and run the PRAGMA to turn journalling off than it does
** to write the journal header file.
*/
nDb = db->nDb;
rc = execSql(db, pzErrMsg, "ATTACH''AS vacuum_db");
if (rc != SQLITE_OK) goto end_of_vacuum;
assert((db->nDb - 1) == nDb);
pDb = &db->aDb[nDb];
assert(strcmp(pDb->zDbSName, "vacuum_db") == 0);
pTemp = pDb->pBt;
/* The call to execSql() to attach the temp database has left the file
** locked (as there was more than one active statement when the transaction
** to read the schema was concluded. Unlock it here so that this doesn't
** cause problems for the call to BtreeSetPageSize() below. */
sqlite3BtreeCommit(pTemp);
/* CHANGE 3 of 3: Do not call sqlite3BtreeGetOptimalReserve */
/* nRes = sqlite3BtreeGetOptimalReserve(pMain); */
/* A VACUUM cannot change the pagesize of an encrypted database. */
#ifdef SQLITE_HAS_CODEC
if (db->nextPagesize) {
extern void sqlite3CodecGetKey(sqlite3*, int, void**, int*);
int nKey;
char *zKey;
sqlite3CodecGetKey(db, iDb, (void**)&zKey, &nKey);
if (nKey) db->nextPagesize = 0;
}
#endif
sqlite3BtreeSetCacheSize(pTemp, db->aDb[iDb].pSchema->cache_size);
sqlite3BtreeSetSpillSize(pTemp, sqlite3BtreeSetSpillSize(pMain, 0));
sqlite3BtreeSetPagerFlags(pTemp, PAGER_SYNCHRONOUS_OFF | PAGER_CACHESPILL);
/* Begin a transaction and take an exclusive lock on the main database
** file. This is done before the sqlite3BtreeGetPageSize(pMain) call below,
** to ensure that we do not try to change the page-size on a WAL database.
*/
rc = execSql(db, pzErrMsg, "BEGIN");
if (rc != SQLITE_OK) goto end_of_vacuum;
rc = sqlite3BtreeBeginTrans(pMain, 2);
if (rc != SQLITE_OK) goto end_of_vacuum;
/* Do not attempt to change the page size for a WAL database */
if (sqlite3PagerGetJournalMode(sqlite3BtreePager(pMain))
== PAGER_JOURNALMODE_WAL) {
db->nextPagesize = 0;
}
if (sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain), nRes, 0)
|| (!isMemDb && sqlite3BtreeSetPageSize(pTemp, db->nextPagesize, nRes, 0))
|| NEVER(db->mallocFailed)
) {
rc = SQLITE_NOMEM_BKPT;
goto end_of_vacuum;
}
#ifndef SQLITE_OMIT_AUTOVACUUM
sqlite3BtreeSetAutoVacuum(pTemp, db->nextAutovac >= 0 ? db->nextAutovac :
sqlite3BtreeGetAutoVacuum(pMain));
#endif
/* Query the schema of the main database. Create a mirror schema
** in the temporary database.
*/
db->init.iDb = nDb; /* force new CREATE statements into vacuum_db */
rc = execSqlF(db, pzErrMsg,
"SELECT sql FROM \"%w\".sqlite_master"
" WHERE type='table'AND name<>'sqlite_sequence'"
" AND coalesce(rootpage,1)>0",
zDbMain
);
if (rc != SQLITE_OK) goto end_of_vacuum;
rc = execSqlF(db, pzErrMsg,
"SELECT sql FROM \"%w\".sqlite_master"
" WHERE type='index'",
zDbMain
);
if (rc != SQLITE_OK) goto end_of_vacuum;
db->init.iDb = 0;
/* Loop through the tables in the main database. For each, do
** an "INSERT INTO vacuum_db.xxx SELECT * FROM main.xxx;" to copy
** the contents to the temporary database.
*/
rc = execSqlF(db, pzErrMsg,
"SELECT'INSERT INTO vacuum_db.'||quote(name)"
"||' SELECT*FROM\"%w\".'||quote(name)"
"FROM vacuum_db.sqlite_master "
"WHERE type='table'AND coalesce(rootpage,1)>0",
zDbMain
);
assert((db->mDbFlags & DBFLAG_Vacuum) != 0);
db->mDbFlags &= ~DBFLAG_Vacuum;
if (rc != SQLITE_OK) goto end_of_vacuum;
/* Copy the triggers, views, and virtual tables from the main database
** over to the temporary database. None of these objects has any
** associated storage, so all we have to do is copy their entries
** from the SQLITE_MASTER table.
*/
rc = execSqlF(db, pzErrMsg,
"INSERT INTO vacuum_db.sqlite_master"
" SELECT*FROM \"%w\".sqlite_master"
" WHERE type IN('view','trigger')"
" OR(type='table'AND rootpage=0)",
zDbMain
);
if (rc) goto end_of_vacuum;
/* At this point, there is a write transaction open on both the
** vacuum database and the main database. Assuming no error occurs,
** both transactions are closed by this block - the main database
** transaction by sqlite3BtreeCopyFile() and the other by an explicit
** call to sqlite3BtreeCommit().
*/
{
u32 meta;
int i;
/* This array determines which meta meta values are preserved in the
** vacuum. Even entries are the meta value number and odd entries
** are an increment to apply to the meta value after the vacuum.
** The increment is used to increase the schema cookie so that other
** connections to the same database will know to reread the schema.
*/
static const unsigned char aCopy[] = {
BTREE_SCHEMA_VERSION, 1, /* Add one to the old schema cookie */
BTREE_DEFAULT_CACHE_SIZE, 0, /* Preserve the default page cache size */
BTREE_TEXT_ENCODING, 0, /* Preserve the text encoding */
BTREE_USER_VERSION, 0, /* Preserve the user version */
BTREE_APPLICATION_ID, 0, /* Preserve the application id */
};
assert(1 == sqlite3BtreeIsInTrans(pTemp));
assert(1 == sqlite3BtreeIsInTrans(pMain));
/* Copy Btree meta values */
for (i = 0; i<ArraySize(aCopy); i += 2) {
/* GetMeta() and UpdateMeta() cannot fail in this context because
** we already have page 1 loaded into cache and marked dirty. */
sqlite3BtreeGetMeta(pMain, aCopy[i], &meta);
rc = sqlite3BtreeUpdateMeta(pTemp, aCopy[i], meta + aCopy[i + 1]);
if (NEVER(rc != SQLITE_OK)) goto end_of_vacuum;
}
rc = sqlite3BtreeCopyFile(pMain, pTemp);
if (rc != SQLITE_OK) goto end_of_vacuum;
rc = sqlite3BtreeCommit(pTemp);
if (rc != SQLITE_OK) goto end_of_vacuum;
#ifndef SQLITE_OMIT_AUTOVACUUM
sqlite3BtreeSetAutoVacuum(pMain, sqlite3BtreeGetAutoVacuum(pTemp));
#endif
}
assert(rc == SQLITE_OK);
rc = sqlite3BtreeSetPageSize(pMain, sqlite3BtreeGetPageSize(pTemp), nRes, 1);
end_of_vacuum:
/* Restore the original value of db->flags */
db->init.iDb = 0;
db->mDbFlags = saved_mDbFlags;
db->flags = saved_flags;
db->nChange = saved_nChange;
db->nTotalChange = saved_nTotalChange;
db->mTrace = saved_mTrace;
sqlite3BtreeSetPageSize(pMain, -1, -1, 1);
/* Currently there is an SQL level transaction open on the vacuum
** database. No locks are held on any other files (since the main file
** was committed at the btree level). So it safe to end the transaction
** by manually setting the autoCommit flag to true and detaching the
** vacuum database. The vacuum_db journal file is deleted when the pager
** is closed by the DETACH.
*/
db->autoCommit = 1;
if (pDb) {
sqlite3BtreeClose(pDb->pBt);
pDb->pBt = 0;
pDb->pSchema = 0;
}
/* This both clears the schemas and reduces the size of the db->aDb[]
** array. */
sqlite3ResetAllSchemasOfConnection(db);
return rc;
}
/*
** This routine implements the OP_Vacuum opcode of the VDBE.
*/
int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
int rc = SQLITE_OK; /* Return code from service routines */
#if !defined(SQLITE_OMIT_VACUUM) || SQLITE_OMIT_VACUUM
const char *zFilename; /* full pathname of the database file */
int nFilename; /* number of characters in zFilename[] */
char *zTemp = 0; /* a temporary file in same directory as zFilename */
int i; /* Loop counter */
Btree *pMain; /* The database being vacuumed */
Btree *pTemp;
char *zSql = 0;
if( !db->autoCommit ){
sqlite3SetString(pzErrMsg, "cannot VACUUM from within a transaction",
(char*)0);
rc = SQLITE_ERROR;
goto end_of_vacuum;
}
/* Get the full pathname of the database file and create a
** temporary filename in the same directory as the original file.
*/
pMain = db->aDb[0].pBt;
zFilename = sqlite3BtreeGetFilename(pMain);
assert( zFilename );
if( zFilename[0]=='\0' ){
/* The in-memory database. Do nothing. Return directly to avoid causing
** an error trying to DETACH the vacuum_db (which never got attached)
** in the exit-handler.
*/
return SQLITE_OK;
}
nFilename = strlen(zFilename);
zTemp = sqliteMalloc( nFilename+100 );
if( zTemp==0 ){
rc = SQLITE_NOMEM;
goto end_of_vacuum;
}
strcpy(zTemp, zFilename);
i = 0;
do {
zTemp[nFilename] = '-';
randomName((unsigned char*)&zTemp[nFilename+1]);
} while( i<10 && sqlite3OsFileExists(zTemp) );
/* Attach the temporary database as 'vacuum_db'. The synchronous pragma
** can be set to 'off' for this file, as it is not recovered if a crash
** occurs anyway. The integrity of the database is maintained by a
** (possibly synchronous) transaction opened on the main database before
** sqlite3BtreeCopyFile() is called.
**
** An optimisation would be to use a non-journaled pager.
*/
zSql = sqlite3MPrintf("ATTACH '%q' AS vacuum_db;", zTemp);
if( !zSql ){
rc = SQLITE_NOMEM;
goto end_of_vacuum;
}
rc = execSql(db, zSql);
sqliteFree(zSql);
zSql = 0;
if( rc!=SQLITE_OK ) goto end_of_vacuum;
assert( strcmp(db->aDb[db->nDb-1].zName,"vacuum_db")==0 );
pTemp = db->aDb[db->nDb-1].pBt;
sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain),
sqlite3BtreeGetReserve(pMain));
assert( sqlite3BtreeGetPageSize(pTemp)==sqlite3BtreeGetPageSize(pMain) );
execSql(db, "PRAGMA vacuum_db.synchronous=OFF");
/* Begin a transaction */
rc = execSql(db, "BEGIN;");
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Query the schema of the main database. Create a mirror schema
** in the temporary database.
*/
rc = execExecSql(db,
"SELECT 'CREATE TABLE vacuum_db.' || substr(sql,14,100000000) "
" FROM sqlite_master WHERE type='table' "
"UNION ALL "
"SELECT 'CREATE INDEX vacuum_db.' || substr(sql,14,100000000) "
" FROM sqlite_master WHERE sql LIKE 'CREATE INDEX %' "
"UNION ALL "
"SELECT 'CREATE UNIQUE INDEX vacuum_db.' || substr(sql,21,100000000) "
" FROM sqlite_master WHERE sql LIKE 'CREATE UNIQUE INDEX %'"
"UNION ALL "
"SELECT 'CREATE VIEW vacuum_db.' || substr(sql,13,100000000) "
" FROM sqlite_master WHERE type='view'"
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Loop through the tables in the main database. For each, do
** an "INSERT INTO vacuum_db.xxx SELECT * FROM xxx;" to copy
** the contents to the temporary database.
*/
rc = execExecSql(db,
"SELECT 'INSERT INTO vacuum_db.' || quote(name) "
"|| ' SELECT * FROM ' || quote(name) || ';'"
"FROM sqlite_master "
"WHERE type = 'table';"
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Copy the triggers from the main database to the temporary database.
** This was deferred before in case the triggers interfered with copying
** the data. It's possible the indices should be deferred until this
** point also.
*/
rc = execExecSql(db,
"SELECT 'CREATE TRIGGER vacuum_db.' || substr(sql, 16, 1000000) "
"FROM sqlite_master WHERE type='trigger'"
);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* At this point, unless the main db was completely empty, there is now a
** transaction open on the vacuum database, but not on the main database.
** Open a btree level transaction on the main database. This allows a
** call to sqlite3BtreeCopyFile(). The main database btree level
** transaction is then committed, so the SQL level never knows it was
** opened for writing. This way, the SQL transaction used to create the
** temporary database never needs to be committed.
*/
if( sqlite3BtreeIsInTrans(pTemp) ){
u32 meta;
assert( 0==sqlite3BtreeIsInTrans(pMain) );
rc = sqlite3BtreeBeginTrans(pMain, 1);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
/* Copy Btree meta values 3 and 4. These correspond to SQL layer meta
** values 2 and 3, the default values of a couple of pragmas.
*/
rc = sqlite3BtreeGetMeta(pMain, 3, &meta);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeUpdateMeta(pTemp, 3, meta);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeGetMeta(pMain, 4, &meta);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeUpdateMeta(pTemp, 4, meta);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeCopyFile(pMain, pTemp);
if( rc!=SQLITE_OK ) goto end_of_vacuum;
rc = sqlite3BtreeCommit(pMain);
}
end_of_vacuum:
/* Currently there is an SQL level transaction open on the vacuum
** database. No locks are held on any other files (since the main file
** was committed at the btree level). So it safe to end the transaction
** by manually setting the autoCommit flag to true and detaching the
** vacuum database. The vacuum_db journal file is deleted when the pager
** is closed by the DETACH.
*/
db->autoCommit = 1;
if( rc==SQLITE_OK ){
rc = execSql(db, "DETACH vacuum_db;");
}else{
execSql(db, "DETACH vacuum_db;");
}
if( zTemp ){
sqlite3OsDelete(zTemp);
sqliteFree(zTemp);
}
if( zSql ) sqliteFree( zSql );
sqlite3ResetInternalSchema(db, 0);
#endif
return rc;
}
