diff options
Diffstat (limited to 'includes/objectcache/SqlBagOStuff.php')
| -rw-r--r-- | includes/objectcache/SqlBagOStuff.php | 314 |
1 files changed, 220 insertions, 94 deletions
diff --git a/includes/objectcache/SqlBagOStuff.php b/includes/objectcache/SqlBagOStuff.php index 93d22f11..54051dc1 100644 --- a/includes/objectcache/SqlBagOStuff.php +++ b/includes/objectcache/SqlBagOStuff.php @@ -1,4 +1,25 @@ <?php +/** + * Object caching using a SQL database. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * http://www.gnu.org/copyleft/gpl.html + * + * @file + * @ingroup Cache + */ /** * Class to store objects in the database @@ -6,7 +27,6 @@ * @ingroup Cache */ class SqlBagOStuff extends BagOStuff { - /** * @var LoadBalancer */ @@ -22,6 +42,9 @@ class SqlBagOStuff extends BagOStuff { var $shards = 1; var $tableName = 'objectcache'; + protected $connFailureTime = 0; // UNIX timestamp + protected $connFailureError; // exception + /** * Constructor. Parameters are: * - server: A server info structure in the format required by each @@ -66,25 +89,40 @@ class SqlBagOStuff extends BagOStuff { * @return DatabaseBase */ protected function getDB() { + global $wgDebugDBTransactions; + + # Don't keep timing out trying to connect for each call if the DB is down + if ( $this->connFailureError && ( time() - $this->connFailureTime ) < 60 ) { + throw $this->connFailureError; + } + if ( !isset( $this->db ) ) { # If server connection info was given, use that if ( $this->serverInfo ) { + if ( $wgDebugDBTransactions ) { + wfDebug( sprintf( "Using provided serverInfo for SqlBagOStuff\n" ) ); + } $this->lb = new LoadBalancer( array( 'servers' => array( $this->serverInfo ) ) ); $this->db = $this->lb->getConnection( DB_MASTER ); $this->db->clearFlag( DBO_TRX ); } else { - # We must keep a separate connection to MySQL in order to avoid deadlocks - # However, SQLite has an opposite behaviour. - # @todo Investigate behaviour for other databases - if ( wfGetDB( DB_MASTER )->getType() == 'sqlite' ) { - $this->db = wfGetDB( DB_MASTER ); - } else { + /* + * We must keep a separate connection to MySQL in order to avoid deadlocks + * However, SQLite has an opposite behaviour. And PostgreSQL needs to know + * if we are in transaction or no + */ + if ( wfGetDB( DB_MASTER )->getType() == 'mysql' ) { $this->lb = wfGetLBFactory()->newMainLB(); $this->db = $this->lb->getConnection( DB_MASTER ); - $this->db->clearFlag( DBO_TRX ); + $this->db->clearFlag( DBO_TRX ); // auto-commit mode + } else { + $this->db = wfGetDB( DB_MASTER ); } } + if ( $wgDebugDBTransactions ) { + wfDebug( sprintf( "Connection %s will be used for SqlBagOStuff\n", $this->db ) ); + } } return $this->db; @@ -92,6 +130,8 @@ class SqlBagOStuff extends BagOStuff { /** * Get the table name for a given key + * @param $key string + * @return string */ protected function getTableByKey( $key ) { if ( $this->shards > 1 ) { @@ -104,6 +144,8 @@ class SqlBagOStuff extends BagOStuff { /** * Get the table name for a given shard index + * @param $index int + * @return string */ protected function getTableByShard( $index ) { if ( $this->shards > 1 ) { @@ -115,61 +157,103 @@ class SqlBagOStuff extends BagOStuff { } } + /** + * @param $key string + * @return mixed + */ public function get( $key ) { - # expire old entries if any - $this->garbageCollect(); - $db = $this->getDB(); - $tableName = $this->getTableByKey( $key ); - $row = $db->selectRow( $tableName, array( 'value', 'exptime' ), - array( 'keyname' => $key ), __METHOD__ ); + $values = $this->getMulti( array( $key ) ); + return array_key_exists( $key, $values ) ? $values[$key] : false; + } - if ( !$row ) { - $this->debug( 'get: no matching rows' ); - return false; - } + /** + * @param $keys array + * @return Array + */ + public function getMulti( array $keys ) { + $values = array(); // array of (key => value) - $this->debug( "get: retrieved data; expiry time is " . $row->exptime ); + try { + $db = $this->getDB(); + $keysByTableName = array(); + foreach ( $keys as $key ) { + $tableName = $this->getTableByKey( $key ); + if ( !isset( $keysByTableName[$tableName] ) ) { + $keysByTableName[$tableName] = array(); + } + $keysByTableName[$tableName][] = $key; + } - if ( $this->isExpired( $row->exptime ) ) { - $this->debug( "get: key has expired, deleting" ); - try { - $db->begin( __METHOD__ ); - # Put the expiry time in the WHERE condition to avoid deleting a - # newly-inserted value - $db->delete( $tableName, - array( - 'keyname' => $key, - 'exptime' => $row->exptime - ), __METHOD__ ); - $db->commit( __METHOD__ ); - } catch ( DBQueryError $e ) { - $this->handleWriteError( $e ); + $this->garbageCollect(); // expire old entries if any + + $dataRows = array(); + foreach ( $keysByTableName as $tableName => $tableKeys ) { + $res = $db->select( $tableName, + array( 'keyname', 'value', 'exptime' ), + array( 'keyname' => $tableKeys ), + __METHOD__ ); + foreach ( $res as $row ) { + $dataRows[$row->keyname] = $row; + } } - return false; - } + foreach ( $keys as $key ) { + if ( isset( $dataRows[$key] ) ) { // HIT? + $row = $dataRows[$key]; + $this->debug( "get: retrieved data; expiry time is " . $row->exptime ); + if ( $this->isExpired( $row->exptime ) ) { // MISS + $this->debug( "get: key has expired, deleting" ); + try { + $db->begin( __METHOD__ ); + # Put the expiry time in the WHERE condition to avoid deleting a + # newly-inserted value + $db->delete( $this->getTableByKey( $key ), + array( 'keyname' => $key, 'exptime' => $row->exptime ), + __METHOD__ ); + $db->commit( __METHOD__ ); + } catch ( DBQueryError $e ) { + $this->handleWriteError( $e ); + } + $values[$key] = false; + } else { // HIT + $values[$key] = $this->unserialize( $db->decodeBlob( $row->value ) ); + } + } else { // MISS + $values[$key] = false; + $this->debug( 'get: no matching rows' ); + } + } + } catch ( DBError $e ) { + $this->handleReadError( $e ); + }; - return $this->unserialize( $db->decodeBlob( $row->value ) ); + return $values; } + /** + * @param $key string + * @param $value mixed + * @param $exptime int + * @return bool + */ public function set( $key, $value, $exptime = 0 ) { - $db = $this->getDB(); - $exptime = intval( $exptime ); - - if ( $exptime < 0 ) { - $exptime = 0; - } + try { + $db = $this->getDB(); + $exptime = intval( $exptime ); - if ( $exptime == 0 ) { - $encExpiry = $this->getMaxDateTime(); - } else { - if ( $exptime < 3.16e8 ) { # ~10 years - $exptime += time(); + if ( $exptime < 0 ) { + $exptime = 0; } - $encExpiry = $db->timestamp( $exptime ); - } - try { + if ( $exptime == 0 ) { + $encExpiry = $this->getMaxDateTime(); + } else { + if ( $exptime < 3.16e8 ) { # ~10 years + $exptime += time(); + } + + $encExpiry = $db->timestamp( $exptime ); + } $db->begin( __METHOD__ ); // (bug 24425) use a replace if the db supports it instead of // delete/insert to avoid clashes with conflicting keynames @@ -182,40 +266,46 @@ class SqlBagOStuff extends BagOStuff { 'exptime' => $encExpiry ), __METHOD__ ); $db->commit( __METHOD__ ); - } catch ( DBQueryError $e ) { + } catch ( DBError $e ) { $this->handleWriteError( $e ); - return false; } return true; } + /** + * @param $key string + * @param $time int + * @return bool + */ public function delete( $key, $time = 0 ) { - $db = $this->getDB(); - try { + $db = $this->getDB(); $db->begin( __METHOD__ ); $db->delete( $this->getTableByKey( $key ), array( 'keyname' => $key ), __METHOD__ ); $db->commit( __METHOD__ ); - } catch ( DBQueryError $e ) { + } catch ( DBError $e ) { $this->handleWriteError( $e ); - return false; } return true; } + /** + * @param $key string + * @param $step int + * @return int|null + */ public function incr( $key, $step = 1 ) { - $db = $this->getDB(); - $tableName = $this->getTableByKey( $key ); - $step = intval( $step ); - try { + $db = $this->getDB(); + $tableName = $this->getTableByKey( $key ); + $step = intval( $step ); $db->begin( __METHOD__ ); $row = $db->selectRow( $tableName, @@ -251,34 +341,47 @@ class SqlBagOStuff extends BagOStuff { $newValue = null; } $db->commit( __METHOD__ ); - } catch ( DBQueryError $e ) { + } catch ( DBError $e ) { $this->handleWriteError( $e ); - return null; } return $newValue; } + /** + * @return Array + */ public function keys() { - $db = $this->getDB(); $result = array(); - for ( $i = 0; $i < $this->shards; $i++ ) { - $res = $db->select( $this->getTableByShard( $i ), - array( 'keyname' ), false, __METHOD__ ); - foreach ( $res as $row ) { - $result[] = $row->keyname; + try { + $db = $this->getDB(); + for ( $i = 0; $i < $this->shards; $i++ ) { + $res = $db->select( $this->getTableByShard( $i ), + array( 'keyname' ), false, __METHOD__ ); + foreach ( $res as $row ) { + $result[] = $row->keyname; + } } + } catch ( DBError $e ) { + $this->handleReadError( $e ); } return $result; } + /** + * @param $exptime string + * @return bool + */ protected function isExpired( $exptime ) { return $exptime != $this->getMaxDateTime() && wfTimestamp( TS_UNIX, $exptime ) < time(); } + /** + * @return string + */ protected function getMaxDateTime() { if ( time() > 0x7fffffff ) { return $this->getDB()->timestamp( 1 << 62 ); @@ -310,14 +413,16 @@ class SqlBagOStuff extends BagOStuff { /** * Delete objects from the database which expire before a certain date. + * @param $timestamp string + * @param $progressCallback bool|callback + * @return bool */ public function deleteObjectsExpiringBefore( $timestamp, $progressCallback = false ) { - $db = $this->getDB(); - $dbTimestamp = $db->timestamp( $timestamp ); - $totalSeconds = false; - $baseConds = array( 'exptime < ' . $db->addQuotes( $dbTimestamp ) ); - try { + $db = $this->getDB(); + $dbTimestamp = $db->timestamp( $timestamp ); + $totalSeconds = false; + $baseConds = array( 'exptime < ' . $db->addQuotes( $dbTimestamp ) ); for ( $i = 0; $i < $this->shards; $i++ ) { $maxExpTime = false; while ( true ) { @@ -325,7 +430,7 @@ class SqlBagOStuff extends BagOStuff { if ( $maxExpTime !== false ) { $conds[] = 'exptime > ' . $db->addQuotes( $maxExpTime ); } - $rows = $db->select( + $rows = $db->select( $this->getTableByShard( $i ), array( 'keyname', 'exptime' ), $conds, @@ -349,7 +454,7 @@ class SqlBagOStuff extends BagOStuff { $db->begin( __METHOD__ ); $db->delete( $this->getTableByShard( $i ), - array( + array( 'exptime >= ' . $db->addQuotes( $minExpTime ), 'exptime < ' . $db->addQuotes( $dbTimestamp ), 'keyname' => $keys @@ -361,36 +466,40 @@ class SqlBagOStuff extends BagOStuff { if ( intval( $totalSeconds ) === 0 ) { $percent = 0; } else { - $remainingSeconds = wfTimestamp( TS_UNIX, $timestamp ) + $remainingSeconds = wfTimestamp( TS_UNIX, $timestamp ) - wfTimestamp( TS_UNIX, $maxExpTime ); if ( $remainingSeconds > $totalSeconds ) { $totalSeconds = $remainingSeconds; } - $percent = ( $i + $remainingSeconds / $totalSeconds ) + $percent = ( $i + $remainingSeconds / $totalSeconds ) / $this->shards * 100; } call_user_func( $progressCallback, $percent ); } } } - } catch ( DBQueryError $e ) { + } catch ( DBError $e ) { $this->handleWriteError( $e ); + return false; } + return true; } public function deleteAll() { - $db = $this->getDB(); - try { + $db = $this->getDB(); for ( $i = 0; $i < $this->shards; $i++ ) { $db->begin( __METHOD__ ); $db->delete( $this->getTableByShard( $i ), '*', __METHOD__ ); $db->commit( __METHOD__ ); } - } catch ( DBQueryError $e ) { + } catch ( DBError $e ) { $this->handleWriteError( $e ); + return false; } + + return true; } /** @@ -433,23 +542,40 @@ class SqlBagOStuff extends BagOStuff { } /** - * Handle a DBQueryError which occurred during a write operation. - * Ignore errors which are due to a read-only database, rethrow others. + * Handle a DBError which occurred during a read operation. */ - protected function handleWriteError( $exception ) { - $db = $this->getDB(); - - if ( !$db->wasReadOnlyError() ) { - throw $exception; + protected function handleReadError( DBError $exception ) { + if ( $exception instanceof DBConnectionError ) { + $this->connFailureTime = time(); + $this->connFailureError = $exception; } - - try { - $db->rollback(); - } catch ( DBQueryError $e ) { + wfDebugLog( 'SQLBagOStuff', "DBError: {$exception->getMessage()}" ); + if ( $this->db ) { + wfDebug( __METHOD__ . ": ignoring query error\n" ); + } else { + wfDebug( __METHOD__ . ": ignoring connection error\n" ); } + } - wfDebug( __METHOD__ . ": ignoring query error\n" ); - $db->ignoreErrors( false ); + /** + * Handle a DBQueryError which occurred during a write operation. + */ + protected function handleWriteError( DBError $exception ) { + if ( $exception instanceof DBConnectionError ) { + $this->connFailureTime = time(); + $this->connFailureError = $exception; + } + if ( $this->db && $this->db->wasReadOnlyError() ) { + try { + $this->db->rollback( __METHOD__ ); + } catch ( DBError $e ) {} + } + wfDebugLog( 'SQLBagOStuff', "DBError: {$exception->getMessage()}" ); + if ( $this->db ) { + wfDebug( __METHOD__ . ": ignoring query error\n" ); + } else { + wfDebug( __METHOD__ . ": ignoring connection error\n" ); + } } /** |