[sql] Import reference version of SQLite 3.10.2.

third_party/sqlite/sqlite-src-3100200/src/vacuum.c

 /*
 ** 2003 April 6
 **
 ** 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.
 **
@@ skipping 76 matching lines @@
 ** step (3) requires additional temporary disk space approximately equal
 ** to the size of the original database for the rollback journal.
 ** Hence, temporary disk space that is approximately 2x the size of the
 ** original database is required.  Every page of the database is written
 ** approximately 3 times:  Once for step (2) and twice for step (3).
 ** Two writes per page are required in step (3) because the original
 ** database content must be written into the rollback journal prior to
 ** overwriting the database with the vacuumed content.
 **
 ** Only 1x temporary space and only 1x writes would be required if
-** the copy of step (3) were replace by deleting the original database
+** the copy of step (3) were replaced by deleting the original database
 ** and renaming the transient database as the original.  But that will
 ** not work if other processes are attached to the original database.
 ** And a power loss in between deleting the original and renaming the
 ** transient would cause the database file to appear to be deleted
 ** following reboot.
 */
 void sqlite3Vacuum(Parse *pParse){
   Vdbe *v = sqlite3GetVdbe(pParse);
   if( v ){
     sqlite3VdbeAddOp2(v, OP_Vacuum, 0, 0);
@@ skipping 69 matching lines @@
   }
   if( rc!=SQLITE_OK ) goto end_of_vacuum;
   pTemp = db->aDb[db->nDb-1].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);
 
-  nRes = sqlite3BtreeGetReserve(pMain);
+  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, 0, (void**)&zKey, &nKey);
     if( nKey ) db->nextPagesize = 0;
   }
@@ skipping 45 matching lines @@
   if( rc!=SQLITE_OK ) goto end_of_vacuum;
   rc = execExecSql(db, pzErrMsg,
       "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 main.xxx;" to copy
   ** the contents to the temporary database.
   */
+  assert( (db->flags & SQLITE_Vacuum)==0 );
+  db->flags |= SQLITE_Vacuum;
   rc = execExecSql(db, pzErrMsg,
       "SELECT 'INSERT INTO vacuum_db.' || quote(name) "
       "|| ' SELECT * FROM main.' || quote(name) || ';'"
       "FROM main.sqlite_master "
       "WHERE type = 'table' AND name!='sqlite_sequence' "
       "  AND coalesce(rootpage,1)>0"
   );
+  assert( (db->flags & SQLITE_Vacuum)!=0 );
+  db->flags &= ~SQLITE_Vacuum;
   if( rc!=SQLITE_OK ) goto end_of_vacuum;
 
   /* Copy over the sequence table
   */
   rc = execExecSql(db, pzErrMsg,
       "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, pzErrMsg,
@@ skipping 90 matching lines @@
   }
 
   /* This both clears the schemas and reduces the size of the db->aDb[]
   ** array. */ 
   sqlite3ResetAllSchemasOfConnection(db);
 
   return rc;
 }
 
 #endif  /* SQLITE_OMIT_VACUUM && SQLITE_OMIT_ATTACH */