DatabaseMysql.php

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<?php
class DatabaseMysql extends DatabaseBase {

        function getType() {
                return 'mysql';
        }

        protected function doQuery( $sql ) {
                if( $this->bufferResults() ) {
                        $ret = mysql_query( $sql, $this->mConn );
                } else {
                        $ret = mysql_unbuffered_query( $sql, $this->mConn );
                }
                return $ret;
        }

        function open( $server, $user, $password, $dbName ) {
                global $wgAllDBsAreLocalhost, $wgDBmysql5, $wgSQLMode;
                wfProfileIn( __METHOD__ );

                # Load mysql.so if we don't have it
                wfDl( 'mysql' );

                # Fail now
                # Otherwise we get a suppressed fatal error, which is very hard to track down
                if ( !function_exists( 'mysql_connect' ) ) {
                        throw new DBConnectionError( $this, "MySQL functions missing, have you compiled PHP with the --with-mysql option?\n" );
                }

                # Debugging hack -- fake cluster
                if ( $wgAllDBsAreLocalhost ) {
                        $realServer = 'localhost';
                } else {
                        $realServer = $server;
                }
                $this->close();
                $this->mServer = $server;
                $this->mUser = $user;
                $this->mPassword = $password;
                $this->mDBname = $dbName;

                $connFlags = 0;
                if ( $this->mFlags & DBO_SSL ) {
                        $connFlags |= MYSQL_CLIENT_SSL;
                }
                if ( $this->mFlags & DBO_COMPRESS ) {
                        $connFlags |= MYSQL_CLIENT_COMPRESS;
                }

                wfProfileIn( "dbconnect-$server" );

                # The kernel's default SYN retransmission period is far too slow for us,
                # so we use a short timeout plus a manual retry. Retrying means that a small
                # but finite rate of SYN packet loss won't cause user-visible errors.
                $this->mConn = false;
                if ( ini_get( 'mysql.connect_timeout' ) <= 3 ) {
                        $numAttempts = 2;
                } else {
                        $numAttempts = 1;
                }
                $this->installErrorHandler();
                for ( $i = 0; $i < $numAttempts && !$this->mConn; $i++ ) {
                        if ( $i > 1 ) {
                                usleep( 1000 );
                        }
                        if ( $this->mFlags & DBO_PERSISTENT ) {
                                $this->mConn = mysql_pconnect( $realServer, $user, $password, $connFlags );
                        } else {
                                # Create a new connection...
                                $this->mConn = mysql_connect( $realServer, $user, $password, true, $connFlags );
                        }
                        #if ( $this->mConn === false ) {
                                #$iplus = $i + 1;
                                #wfLogDBError("Connect loop error $iplus of $max ($server): " . mysql_errno() . " - " . mysql_error()."\n");
                        #}
                }
                $error = $this->restoreErrorHandler();

                wfProfileOut( "dbconnect-$server" );

                # Always log connection errors
                if ( !$this->mConn ) {
                        if ( !$error ) {
                                $error = $this->lastError();
                        }
                        wfLogDBError( "Error connecting to {$this->mServer}: $error\n" );
                        wfDebug( "DB connection error\n" .
                                "Server: $server, User: $user, Password: " .
                                substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );

                        wfProfileOut( __METHOD__ );
                        return $this->reportConnectionError( $error );
                }

                if ( $dbName != '' ) {
                        wfSuppressWarnings();
                        $success = mysql_select_db( $dbName, $this->mConn );
                        wfRestoreWarnings();
                        if ( !$success ) {
                                wfLogDBError( "Error selecting database $dbName on server {$this->mServer}\n" );
                                wfDebug( "Error selecting database $dbName on server {$this->mServer} " .
                                        "from client host " . wfHostname() . "\n" );

                                wfProfileOut( __METHOD__ );
                                return $this->reportConnectionError( "Error selecting database $dbName" );
                        }
                }

                // Tell the server we're communicating with it in UTF-8.
                // This may engage various charset conversions.
                if( $wgDBmysql5 ) {
                        $this->query( 'SET NAMES utf8', __METHOD__ );
                } else {
                        $this->query( 'SET NAMES binary', __METHOD__ );
                }
                // Set SQL mode, default is turning them all off, can be overridden or skipped with null
                if ( is_string( $wgSQLMode ) ) {
                        $mode = $this->addQuotes( $wgSQLMode );
                        $this->query( "SET sql_mode = $mode", __METHOD__ );
                }

                $this->mOpened = true;
                wfProfileOut( __METHOD__ );
                return true;
        }

        protected function closeConnection() {
                return mysql_close( $this->mConn );
        }

        function freeResult( $res ) {
                if ( $res instanceof ResultWrapper ) {
                        $res = $res->result;
                }
                wfSuppressWarnings();
                $ok = mysql_free_result( $res );
                wfRestoreWarnings();
                if ( !$ok ) {
                        throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
                }
        }

        function fetchObject( $res ) {
                if ( $res instanceof ResultWrapper ) {
                        $res = $res->result;
                }
                wfSuppressWarnings();
                $row = mysql_fetch_object( $res );
                wfRestoreWarnings();

                $errno = $this->lastErrno();
                // Unfortunately, mysql_fetch_object does not reset the last errno.
                // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
                // these are the only errors mysql_fetch_object can cause.
                // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
                if( $errno == 2000 || $errno == 2013 ) {
                        throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
                }
                return $row;
        }

        function fetchRow( $res ) {
                if ( $res instanceof ResultWrapper ) {
                        $res = $res->result;
                }
                wfSuppressWarnings();
                $row = mysql_fetch_array( $res );
                wfRestoreWarnings();

                $errno = $this->lastErrno();
                // Unfortunately, mysql_fetch_array does not reset the last errno.
                // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
                // these are the only errors mysql_fetch_object can cause.
                // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
                if( $errno == 2000 || $errno == 2013 ) {
                        throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
                }
                return $row;
        }

        function numRows( $res ) {
                if ( $res instanceof ResultWrapper ) {
                        $res = $res->result;
                }
                wfSuppressWarnings();
                $n = mysql_num_rows( $res );
                wfRestoreWarnings();
                // Unfortunately, mysql_num_rows does not reset the last errno.
                // We are not checking for any errors here, since
                // these are no errors mysql_num_rows can cause.
                // See http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
                // See https://bugzilla.wikimedia.org/42430
                return $n;
        }

        function numFields( $res ) {
                if ( $res instanceof ResultWrapper ) {
                        $res = $res->result;
                }
                return mysql_num_fields( $res );
        }

        function fieldName( $res, $n ) {
                if ( $res instanceof ResultWrapper ) {
                        $res = $res->result;
                }
                return mysql_field_name( $res, $n );
        }

        function insertId() {
                return mysql_insert_id( $this->mConn );
        }

        function dataSeek( $res, $row ) {
                if ( $res instanceof ResultWrapper ) {
                        $res = $res->result;
                }
                return mysql_data_seek( $res, $row );
        }

        function lastErrno() {
                if ( $this->mConn ) {
                        return mysql_errno( $this->mConn );
                } else {
                        return mysql_errno();
                }
        }

        function lastError() {
                if ( $this->mConn ) {
                        # Even if it's non-zero, it can still be invalid
                        wfSuppressWarnings();
                        $error = mysql_error( $this->mConn );
                        if ( !$error ) {
                                $error = mysql_error();
                        }
                        wfRestoreWarnings();
                } else {
                        $error = mysql_error();
                }
                if( $error ) {
                        $error .= ' (' . $this->mServer . ')';
                }
                return $error;
        }

        function affectedRows() {
                return mysql_affected_rows( $this->mConn );
        }

        function replace( $table, $uniqueIndexes, $rows, $fname = 'DatabaseMysql::replace' ) {
                return $this->nativeReplace( $table, $rows, $fname );
        }

        public function estimateRowCount( $table, $vars = '*', $conds = '', $fname = 'DatabaseMysql::estimateRowCount', $options = array() ) {
                $options['EXPLAIN'] = true;
                $res = $this->select( $table, $vars, $conds, $fname, $options );
                if ( $res === false ) {
                        return false;
                }
                if ( !$this->numRows( $res ) ) {
                        return 0;
                }

                $rows = 1;
                foreach ( $res as $plan ) {
                        $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
                }
                return $rows;
        }

        function fieldInfo( $table, $field ) {
                $table = $this->tableName( $table );
                $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
                if ( !$res ) {
                        return false;
                }
                $n = mysql_num_fields( $res->result );
                for( $i = 0; $i < $n; $i++ ) {
                        $meta = mysql_fetch_field( $res->result, $i );
                        if( $field == $meta->name ) {
                                return new MySQLField( $meta );
                        }
                }
                return false;
        }

        function indexInfo( $table, $index, $fname = 'DatabaseMysql::indexInfo' ) {
                # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
                # SHOW INDEX should work for 3.x and up:
                # http://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
                $table = $this->tableName( $table );
                $index = $this->indexName( $index );

                $sql = 'SHOW INDEX FROM ' . $table;
                $res = $this->query( $sql, $fname );

                if ( !$res ) {
                        return null;
                }

                $result = array();

                foreach ( $res as $row ) {
                        if ( $row->Key_name == $index ) {
                                $result[] = $row;
                        }
                }
                return empty( $result ) ? false : $result;
        }

        function selectDB( $db ) {
                $this->mDBname = $db;
                return mysql_select_db( $db, $this->mConn );
        }

        function strencode( $s ) {
                $sQuoted = mysql_real_escape_string( $s, $this->mConn );

                if( $sQuoted === false ) {
                        $this->ping();
                        $sQuoted = mysql_real_escape_string( $s, $this->mConn );
                }
                return $sQuoted;
        }

        public function addIdentifierQuotes( $s ) {
                return "`" . $this->strencode( $s ) . "`";
        }

        public function isQuotedIdentifier( $name ) {
                return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
        }

        function ping() {
                $ping = mysql_ping( $this->mConn );
                if ( $ping ) {
                        return true;
                }

                mysql_close( $this->mConn );
                $this->mOpened = false;
                $this->mConn = false;
                $this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
                return true;
        }

        function getLag() {
                if ( !is_null( $this->mFakeSlaveLag ) ) {
                        wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
                        return $this->mFakeSlaveLag;
                }

                return $this->getLagFromSlaveStatus();
        }

        function getLagFromSlaveStatus() {
                $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
                if ( !$res ) {
                        return false;
                }
                $row = $res->fetchObject();
                if ( !$row ) {
                        return false;
                }
                if ( strval( $row->Seconds_Behind_Master ) === '' ) {
                        return false;
                } else {
                        return intval( $row->Seconds_Behind_Master );
                }
        }

        function getLagFromProcesslist() {
                wfDeprecated( __METHOD__, '1.19' );
                $res = $this->query( 'SHOW PROCESSLIST', __METHOD__ );
                if( !$res ) {
                        return false;
                }
                # Find slave SQL thread
                foreach( $res as $row ) {
                        /* This should work for most situations - when default db
                         * for thread is not specified, it had no events executed,
                         * and therefore it doesn't know yet how lagged it is.
                         *
                         * Relay log I/O thread does not select databases.
                         */
                        if ( $row->User == 'system user' &&
                                $row->State != 'Waiting for master to send event' &&
                                $row->State != 'Connecting to master' &&
                                $row->State != 'Queueing master event to the relay log' &&
                                $row->State != 'Waiting for master update' &&
                                $row->State != 'Requesting binlog dump' &&
                                $row->State != 'Waiting to reconnect after a failed master event read' &&
                                $row->State != 'Reconnecting after a failed master event read' &&
                                $row->State != 'Registering slave on master'
                                ) {
                                # This is it, return the time (except -ve)
                                if ( $row->Time > 0x7fffffff ) {
                                        return false;
                                } else {
                                        return $row->Time;
                                }
                        }
                }
                return false;
        }

        function masterPosWait( DBMasterPos $pos, $timeout ) {
                $fname = 'DatabaseBase::masterPosWait';
                wfProfileIn( $fname );

                # Commit any open transactions
                if ( $this->mTrxLevel ) {
                        $this->commit( __METHOD__ );
                }

                if ( !is_null( $this->mFakeSlaveLag ) ) {
                        $status = parent::masterPosWait( $pos, $timeout );
                        wfProfileOut( $fname );
                        return $status;
                }

                # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
                $encFile = $this->addQuotes( $pos->file );
                $encPos = intval( $pos->pos );
                $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
                $res = $this->doQuery( $sql );

                if ( $res && $row = $this->fetchRow( $res ) ) {
                        wfProfileOut( $fname );
                        return $row[0];
                }
                wfProfileOut( $fname );
                return false;
        }

        function getSlavePos() {
                if ( !is_null( $this->mFakeSlaveLag ) ) {
                        return parent::getSlavePos();
                }

                $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
                $row = $this->fetchObject( $res );

                if ( $row ) {
                        $pos = isset( $row->Exec_master_log_pos ) ? $row->Exec_master_log_pos : $row->Exec_Master_Log_Pos;
                        return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
                } else {
                        return false;
                }
        }

        function getMasterPos() {
                if ( $this->mFakeMaster ) {
                        return parent::getMasterPos();
                }

                $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
                $row = $this->fetchObject( $res );

                if ( $row ) {
                        return new MySQLMasterPos( $row->File, $row->Position );
                } else {
                        return false;
                }
        }

        function getServerVersion() {
                return mysql_get_server_info( $this->mConn );
        }

        function useIndexClause( $index ) {
                return "FORCE INDEX (" . $this->indexName( $index ) . ")";
        }

        function lowPriorityOption() {
                return 'LOW_PRIORITY';
        }

        public static function getSoftwareLink() {
                return '[http://www.mysql.com/ MySQL]';
        }

        public function setSessionOptions( array $options ) {
                if ( isset( $options['connTimeout'] ) ) {
                        $timeout = (int)$options['connTimeout'];
                        $this->query( "SET net_read_timeout=$timeout" );
                        $this->query( "SET net_write_timeout=$timeout" );
                }
        }

        public function streamStatementEnd( &$sql, &$newLine ) {
                if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
                        preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
                        $this->delimiter = $m[1];
                        $newLine = '';
                }
                return parent::streamStatementEnd( $sql, $newLine );
        }

        public function lockIsFree( $lockName, $method ) {
                $lockName = $this->addQuotes( $lockName );
                $result = $this->query( "SELECT IS_FREE_LOCK($lockName) AS lockstatus", $method );
                $row = $this->fetchObject( $result );
                return ( $row->lockstatus == 1 );
        }

        public function lock( $lockName, $method, $timeout = 5 ) {
                $lockName = $this->addQuotes( $lockName );
                $result = $this->query( "SELECT GET_LOCK($lockName, $timeout) AS lockstatus", $method );
                $row = $this->fetchObject( $result );

                if( $row->lockstatus == 1 ) {
                        return true;
                } else {
                        wfDebug( __METHOD__ . " failed to acquire lock\n" );
                        return false;
                }
        }

        public function unlock( $lockName, $method ) {
                $lockName = $this->addQuotes( $lockName );
                $result = $this->query( "SELECT RELEASE_LOCK($lockName) as lockstatus", $method );
                $row = $this->fetchObject( $result );
                return ( $row->lockstatus == 1 );
        }

        public function lockTables( $read, $write, $method, $lowPriority = true ) {
                $items = array();

                foreach( $write as $table ) {
                        $tbl = $this->tableName( $table ) .
                                        ( $lowPriority ? ' LOW_PRIORITY' : '' ) .
                                        ' WRITE';
                        $items[] = $tbl;
                }
                foreach( $read as $table ) {
                        $items[] = $this->tableName( $table ) . ' READ';
                }
                $sql = "LOCK TABLES " . implode( ',', $items );
                $this->query( $sql, $method );
                return true;
        }

        public function unlockTables( $method ) {
                $this->query( "UNLOCK TABLES", $method );
                return true;
        }

        public function getSearchEngine() {
                return 'SearchMySQL';
        }

        public function setBigSelects( $value = true ) {
                if ( $value === 'default' ) {
                        if ( $this->mDefaultBigSelects === null ) {
                                # Function hasn't been called before so it must already be set to the default
                                return;
                        } else {
                                $value = $this->mDefaultBigSelects;
                        }
                } elseif ( $this->mDefaultBigSelects === null ) {
                        $this->mDefaultBigSelects = (bool)$this->selectField( false, '@@sql_big_selects' );
                }
                $encValue = $value ? '1' : '0';
                $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
        }

        function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = 'DatabaseBase::deleteJoin' ) {
                if ( !$conds ) {
                        throw new DBUnexpectedError( $this, 'DatabaseBase::deleteJoin() called with empty $conds' );
                }

                $delTable = $this->tableName( $delTable );
                $joinTable = $this->tableName( $joinTable );
                $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";

                if ( $conds != '*' ) {
                        $sql .= ' AND ' . $this->makeList( $conds, LIST_AND );
                }

                return $this->query( $sql, $fname );
        }

        function getServerUptime() {
                $vars = $this->getMysqlStatus( 'Uptime' );
                return (int)$vars['Uptime'];
        }

        function wasDeadlock() {
                return $this->lastErrno() == 1213;
        }

        function wasLockTimeout() {
                return $this->lastErrno() == 1205;
        }

        function wasErrorReissuable() {
                return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
        }

        function wasReadOnlyError() {
                return $this->lastErrno() == 1223 ||
                        ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
        }

        function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabaseMysql::duplicateTableStructure' ) {
                $tmp = $temporary ? 'TEMPORARY ' : '';
                $newName = $this->addIdentifierQuotes( $newName );
                $oldName = $this->addIdentifierQuotes( $oldName );
                $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
                $this->query( $query, $fname );
        }

        function listTables( $prefix = null, $fname = 'DatabaseMysql::listTables' ) {
                $result = $this->query( "SHOW TABLES", $fname);

                $endArray = array();

                foreach( $result as $table ) {
                        $vars = get_object_vars( $table );
                        $table = array_pop( $vars );

                        if( !$prefix || strpos( $table, $prefix ) === 0 ) {
                                $endArray[] = $table;
                        }
                }

                return $endArray;
        }

        public function dropTable( $tableName, $fName = 'DatabaseMysql::dropTable' ) {
                if( !$this->tableExists( $tableName, $fName ) ) {
                        return false;
                }
                return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
        }

        protected function getDefaultSchemaVars() {
                $vars = parent::getDefaultSchemaVars();
                $vars['wgDBTableOptions'] = str_replace( 'TYPE', 'ENGINE', $GLOBALS['wgDBTableOptions'] );
                $vars['wgDBTableOptions'] = str_replace( 'CHARSET=mysql4', 'CHARSET=binary', $vars['wgDBTableOptions'] );
                return $vars;
        }

        function getMysqlStatus( $which = "%" ) {
                $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
                $status = array();

                foreach ( $res as $row ) {
                        $status[$row->Variable_name] = $row->Value;
                }

                return $status;
        }

}

class MySQLField implements Field {
        private $name, $tablename, $default, $max_length, $nullable,
                $is_pk, $is_unique, $is_multiple, $is_key, $type;

        function __construct ( $info ) {
                $this->name = $info->name;
                $this->tablename = $info->table;
                $this->default = $info->def;
                $this->max_length = $info->max_length;
                $this->nullable = !$info->not_null;
                $this->is_pk = $info->primary_key;
                $this->is_unique = $info->unique_key;
                $this->is_multiple = $info->multiple_key;
                $this->is_key = ( $this->is_pk || $this->is_unique || $this->is_multiple );
                $this->type = $info->type;
        }

        function name() {
                return $this->name;
        }

        function tableName() {
                return $this->tableName;
        }

        function type() {
                return $this->type;
        }

        function isNullable() {
                return $this->nullable;
        }

        function defaultValue() {
                return $this->default;
        }

        function isKey() {
                return $this->is_key;
        }

        function isMultipleKey() {
                return $this->is_multiple;
        }
}

class MySQLMasterPos implements DBMasterPos {
        var $file, $pos;

        function __construct( $file, $pos ) {
                $this->file = $file;
                $this->pos = $pos;
        }

        function __toString() {
                return "{$this->file}/{$this->pos}";
        }
}