wiki.techinc.nl/includes/db/DatabaseMysql.php
2010-11-28 16:13:13 +00:00

596 lines
15 KiB
PHP

<?php
/**
* This is the MySQL database abstraction layer.
*
* @file
* @ingroup Database
*/
/**
* Database abstraction object for mySQL
* Inherit all methods and properties of Database::Database()
*
* @ingroup Database
* @see Database
*/
class DatabaseMysql extends DatabaseBase {
function getType() {
return 'mysql';
}
/*private*/ 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;
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 = $dbName;
wfProfileIn("dbconnect-$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 );
} else {
# Create a new connection...
$this->mConn = mysql_connect( $realServer, $user, $password, true );
}
#if ( $this->mConn === false ) {
#$iplus = $i + 1;
#wfLogDBError("Connect loop error $iplus of $max ($server): " . mysql_errno() . " - " . mysql_error()."\n");
#}
}
$phpError = $this->restoreErrorHandler();
# Always log connection errors
if ( !$this->mConn ) {
$error = $this->lastError();
if ( !$error ) {
$error = $phpError;
}
wfLogDBError( "Error connecting to {$this->mServer}: $error\n" );
wfDebug( "DB connection error\n" );
wfDebug( "Server: $server, User: $user, Password: " .
substr( $password, 0, 3 ) . "..., error: " . mysql_error() . "\n" );
$success = false;
}
wfProfileOut("dbconnect-$server");
if ( $dbName != '' && $this->mConn !== false ) {
$success = @/**/mysql_select_db( $dbName, $this->mConn );
if ( !$success ) {
$error = "Error selecting database $dbName on server {$this->mServer} " .
"from client host " . wfHostname() . "\n";
wfLogDBError(" Error selecting database $dbName on server {$this->mServer} \n");
wfDebug( $error );
}
} else {
# Delay USE query
$success = (bool)$this->mConn;
}
if ( $success ) {
$version = $this->getServerVersion();
if ( version_compare( $version, '4.1' ) >= 0 ) {
// Tell the server we're communicating with it in UTF-8.
// This may engage various charset conversions.
global $wgDBmysql5;
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
global $wgSQLMode;
if ( is_string( $wgSQLMode ) ) {
$mode = $this->addQuotes( $wgSQLMode );
$this->query( "SET sql_mode = $mode", __METHOD__ );
}
}
// Turn off strict mode if it is on
} else {
$this->reportConnectionError( $phpError );
}
$this->mOpened = $success;
wfProfileOut( __METHOD__ );
return $success;
}
function close() {
$this->mOpened = false;
if ( $this->mConn ) {
if ( $this->trxLevel() ) {
$this->commit();
}
return mysql_close( $this->mConn );
} else {
return true;
}
}
function freeResult( $res ) {
if ( $res instanceof ResultWrapper ) {
$res = $res->result;
}
if ( !@/**/mysql_free_result( $res ) ) {
throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
}
}
function fetchObject( $res ) {
if ( $res instanceof ResultWrapper ) {
$res = $res->result;
}
@/**/$row = mysql_fetch_object( $res );
if( $this->lastErrno() ) {
throw new DBUnexpectedError( $this, 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() ) );
}
return $row;
}
function fetchRow( $res ) {
if ( $res instanceof ResultWrapper ) {
$res = $res->result;
}
@/**/$row = mysql_fetch_array( $res );
if ( $this->lastErrno() ) {
throw new DBUnexpectedError( $this, 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() ) );
}
return $row;
}
function numRows( $res ) {
if ( $res instanceof ResultWrapper ) {
$res = $res->result;
}
@/**/$n = mysql_num_rows( $res );
if( $this->lastErrno() ) {
throw new DBUnexpectedError( $this, 'Error in numRows(): ' . htmlspecialchars( $this->lastError() ) );
}
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 ); }
/**
* Estimate rows in dataset
* Returns estimated count, based on EXPLAIN output
* Takes same arguments as Database::select()
*/
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;
}
/**
* Get information about an index into an object
* Returns false if the index does not exist
*/
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;
}
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;
}
/**
* Returns slave lag.
* At the moment, this will only work if the DB user has the PROCESS privilege
* @result int
*/
function getLag() {
if ( !is_null( $this->mFakeSlaveLag ) ) {
wfDebug( "getLag: fake slave lagged {$this->mFakeSlaveLag} seconds\n" );
return $this->mFakeSlaveLag;
}
$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 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]';
}
function standardSelectDistinct() {
return false;
}
public function setTimeout( $timeout ) {
$this->query( "SET net_read_timeout=$timeout" );
$this->query( "SET net_write_timeout=$timeout" );
}
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;
}
}
/**
* FROM MYSQL DOCS: http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
*/
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;
}
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 );
}
public function unlockTables( $method ) {
$this->query( "UNLOCK TABLES", $method );
}
/**
* Get search engine class. All subclasses of this
* need to implement this if they wish to use searching.
*
* @return String
*/
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__ );
}
public function unixTimestamp( $field ) {
return "UNIX_TIMESTAMP($field)";
}
/**
* Determines if the last failure was due to a deadlock
*/
function wasDeadlock() {
return $this->lastErrno() == 1213;
}
/**
* Determines if the last query error was something that should be dealt
* with by pinging the connection and reissuing the query
*/
function wasErrorReissuable() {
return $this->lastErrno() == 2013 || $this->lastErrno() == 2006;
}
/**
* Determines if the last failure was due to the database being read-only.
*/
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 ' : '';
if ( strcmp( $this->getServerVersion(), '4.1' ) < 0 ) {
# Hack for MySQL versions < 4.1, which don't support
# "CREATE TABLE ... LIKE". Note that
# "CREATE TEMPORARY TABLE ... SELECT * FROM ... LIMIT 0"
# would not create the indexes we need....
#
# Note that we don't bother changing around the prefixes here be-
# cause we know we're using MySQL anyway.
$res = $this->query( "SHOW CREATE TABLE $oldName" );
$row = $this->fetchRow( $res );
$oldQuery = $row[1];
$query = preg_replace( '/CREATE TABLE `(.*?)`/',
"CREATE $tmp TABLE `$newName`", $oldQuery );
if ($oldQuery === $query) {
# Couldn't do replacement
throw new MWException( "could not create temporary table $newName" );
}
} else {
$query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
}
$this->query( $query, $fname );
}
}
/**
* Legacy support: Database == DatabaseMysql
*/
class Database extends DatabaseMysql {}
/**
* Utility class.
* @ingroup Database
*/
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 {
var $file, $pos;
function __construct( $file, $pos ) {
$this->file = $file;
$this->pos = $pos;
}
function __toString() {
return "{$this->file}/{$this->pos}";
}
}