Current File : //www/varak.net/wiki.varak.net/includes/db/Database.php
<?php
/**
* @defgroup Database Database
*
* This file deals with database interface functions
* and query specifics/optimisations.
*
* 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 Database
*/
/**
* Database abstraction object
* @ingroup Database
*/
abstract class DatabaseBase implements IDatabase {
/** Number of times to re-try an operation in case of deadlock */
const DEADLOCK_TRIES = 4;
/** Minimum time to wait before retry, in microseconds */
const DEADLOCK_DELAY_MIN = 500000;
/** Maximum time to wait before retry */
const DEADLOCK_DELAY_MAX = 1500000;
/** How long before it is worth doing a dummy query to test the connection */
const PING_TTL = 1.0;
const PING_QUERY = 'SELECT 1 AS ping';
const TINY_WRITE_SEC = .010;
const SLOW_WRITE_SEC = .500;
const SMALL_WRITE_ROWS = 100;
/** @var string SQL query */
protected $mLastQuery = '';
/** @var bool */
protected $mDoneWrites = false;
/** @var string|bool */
protected $mPHPError = false;
/** @var string */
protected $mServer;
/** @var string */
protected $mUser;
/** @var string */
protected $mPassword;
/** @var string */
protected $mDBname;
/** @var BagOStuff APC cache */
protected $srvCache;
/** @var resource Database connection */
protected $mConn = null;
/** @var bool */
protected $mOpened = false;
/** @var array[] List of (callable, method name) */
protected $mTrxIdleCallbacks = [];
/** @var array[] List of (callable, method name) */
protected $mTrxPreCommitCallbacks = [];
/** @var array[] List of (callable, method name) */
protected $mTrxEndCallbacks = [];
/** @var array[] Map of (name => (callable, method name)) */
protected $mTrxRecurringCallbacks = [];
/** @var bool Whether to suppress triggering of transaction end callbacks */
protected $mTrxEndCallbacksSuppressed = false;
/** @var string */
protected $mTablePrefix;
/** @var string */
protected $mSchema;
/** @var integer */
protected $mFlags;
/** @var bool */
protected $mForeign;
/** @var array */
protected $mLBInfo = [];
/** @var bool|null */
protected $mDefaultBigSelects = null;
/** @var array|bool */
protected $mSchemaVars = false;
/** @var array */
protected $mSessionVars = [];
/** @var array|null */
protected $preparedArgs;
/** @var string|bool|null Stashed value of html_errors INI setting */
protected $htmlErrors;
/** @var string */
protected $delimiter = ';';
/**
* Either 1 if a transaction is active or 0 otherwise.
* The other Trx fields may not be meaningfull if this is 0.
*
* @var int
*/
protected $mTrxLevel = 0;
/**
* Either a short hexidecimal string if a transaction is active or ""
*
* @var string
* @see DatabaseBase::mTrxLevel
*/
protected $mTrxShortId = '';
/**
* The UNIX time that the transaction started. Callers can assume that if
* snapshot isolation is used, then the data is *at least* up to date to that
* point (possibly more up-to-date since the first SELECT defines the snapshot).
*
* @var float|null
* @see DatabaseBase::mTrxLevel
*/
private $mTrxTimestamp = null;
/** @var float Lag estimate at the time of BEGIN */
private $mTrxSlaveLag = null;
/**
* Remembers the function name given for starting the most recent transaction via begin().
* Used to provide additional context for error reporting.
*
* @var string
* @see DatabaseBase::mTrxLevel
*/
private $mTrxFname = null;
/**
* Record if possible write queries were done in the last transaction started
*
* @var bool
* @see DatabaseBase::mTrxLevel
*/
private $mTrxDoneWrites = false;
/**
* Record if the current transaction was started implicitly due to DBO_TRX being set.
*
* @var bool
* @see DatabaseBase::mTrxLevel
*/
private $mTrxAutomatic = false;
/**
* Array of levels of atomicity within transactions
*
* @var array
*/
private $mTrxAtomicLevels = [];
/**
* Record if the current transaction was started implicitly by DatabaseBase::startAtomic
*
* @var bool
*/
private $mTrxAutomaticAtomic = false;
/**
* Track the write query callers of the current transaction
*
* @var string[]
*/
private $mTrxWriteCallers = [];
/**
* @var float Seconds spent in write queries for the current transaction
*/
private $mTrxWriteDuration = 0.0;
/**
* @var integer Number of write queries for the current transaction
*/
private $mTrxWriteQueryCount = 0;
/**
* @var float Like mTrxWriteQueryCount but excludes lock-bound, easy to replicate, queries
*/
private $mTrxWriteAdjDuration = 0.0;
/**
* @var integer Number of write queries counted in mTrxWriteAdjDuration
*/
private $mTrxWriteAdjQueryCount = 0;
/**
* @var float RTT time estimate
*/
private $mRTTEstimate = 0.0;
/** @var array Map of (name => 1) for locks obtained via lock() */
private $mNamedLocksHeld = [];
/** @var IDatabase|null Lazy handle to the master DB this server replicates from */
private $lazyMasterHandle;
/**
* @since 1.21
* @var resource File handle for upgrade
*/
protected $fileHandle = null;
/**
* @since 1.22
* @var string[] Process cache of VIEWs names in the database
*/
protected $allViews = null;
/** @var float UNIX timestamp */
protected $lastPing = 0.0;
/** @var int[] Prior mFlags values */
private $priorFlags = [];
/** @var Profiler */
protected $profiler;
/** @var TransactionProfiler */
protected $trxProfiler;
public function getServerInfo() {
return $this->getServerVersion();
}
/**
* @return string Command delimiter used by this database engine
*/
public function getDelimiter() {
return $this->delimiter;
}
/**
* Boolean, controls output of large amounts of debug information.
* @param bool|null $debug
* - true to enable debugging
* - false to disable debugging
* - omitted or null to do nothing
*
* @return bool|null Previous value of the flag
*/
public function debug( $debug = null ) {
return wfSetBit( $this->mFlags, DBO_DEBUG, $debug );
}
public function bufferResults( $buffer = null ) {
if ( is_null( $buffer ) ) {
return !(bool)( $this->mFlags & DBO_NOBUFFER );
} else {
return !wfSetBit( $this->mFlags, DBO_NOBUFFER, !$buffer );
}
}
/**
* Turns on (false) or off (true) the automatic generation and sending
* of a "we're sorry, but there has been a database error" page on
* database errors. Default is on (false). When turned off, the
* code should use lastErrno() and lastError() to handle the
* situation as appropriate.
*
* Do not use this function outside of the Database classes.
*
* @param null|bool $ignoreErrors
* @return bool The previous value of the flag.
*/
protected function ignoreErrors( $ignoreErrors = null ) {
return wfSetBit( $this->mFlags, DBO_IGNORE, $ignoreErrors );
}
public function trxLevel() {
return $this->mTrxLevel;
}
public function trxTimestamp() {
return $this->mTrxLevel ? $this->mTrxTimestamp : null;
}
public function tablePrefix( $prefix = null ) {
return wfSetVar( $this->mTablePrefix, $prefix );
}
public function dbSchema( $schema = null ) {
return wfSetVar( $this->mSchema, $schema );
}
/**
* Set the filehandle to copy write statements to.
*
* @param resource $fh File handle
*/
public function setFileHandle( $fh ) {
$this->fileHandle = $fh;
}
public function getLBInfo( $name = null ) {
if ( is_null( $name ) ) {
return $this->mLBInfo;
} else {
if ( array_key_exists( $name, $this->mLBInfo ) ) {
return $this->mLBInfo[$name];
} else {
return null;
}
}
}
public function setLBInfo( $name, $value = null ) {
if ( is_null( $value ) ) {
$this->mLBInfo = $name;
} else {
$this->mLBInfo[$name] = $value;
}
}
/**
* Set a lazy-connecting DB handle to the master DB (for replication status purposes)
*
* @param IDatabase $conn
* @since 1.27
*/
public function setLazyMasterHandle( IDatabase $conn ) {
$this->lazyMasterHandle = $conn;
}
/**
* @return IDatabase|null
* @see setLazyMasterHandle()
* @since 1.27
*/
public function getLazyMasterHandle() {
return $this->lazyMasterHandle;
}
/**
* @return TransactionProfiler
*/
protected function getTransactionProfiler() {
return $this->trxProfiler;
}
/**
* @param TransactionProfiler $profiler
* @since 1.27
*/
public function setTransactionProfiler( TransactionProfiler $profiler ) {
$this->trxProfiler = $profiler;
}
/**
* Returns true if this database supports (and uses) cascading deletes
*
* @return bool
*/
public function cascadingDeletes() {
return false;
}
/**
* Returns true if this database supports (and uses) triggers (e.g. on the page table)
*
* @return bool
*/
public function cleanupTriggers() {
return false;
}
/**
* Returns true if this database is strict about what can be put into an IP field.
* Specifically, it uses a NULL value instead of an empty string.
*
* @return bool
*/
public function strictIPs() {
return false;
}
/**
* Returns true if this database uses timestamps rather than integers
*
* @return bool
*/
public function realTimestamps() {
return false;
}
public function implicitGroupby() {
return true;
}
public function implicitOrderby() {
return true;
}
/**
* Returns true if this database can do a native search on IP columns
* e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
*
* @return bool
*/
public function searchableIPs() {
return false;
}
/**
* Returns true if this database can use functional indexes
*
* @return bool
*/
public function functionalIndexes() {
return false;
}
public function lastQuery() {
return $this->mLastQuery;
}
public function doneWrites() {
return (bool)$this->mDoneWrites;
}
public function lastDoneWrites() {
return $this->mDoneWrites ?: false;
}
public function writesPending() {
return $this->mTrxLevel && $this->mTrxDoneWrites;
}
public function writesOrCallbacksPending() {
return $this->mTrxLevel && (
$this->mTrxDoneWrites || $this->mTrxIdleCallbacks || $this->mTrxPreCommitCallbacks
);
}
public function pendingWriteQueryDuration( $type = self::ESTIMATE_TOTAL ) {
if ( !$this->mTrxLevel ) {
return false;
} elseif ( !$this->mTrxDoneWrites ) {
return 0.0;
}
switch ( $type ) {
case self::ESTIMATE_DB_APPLY:
$this->ping( $rtt );
$rttAdjTotal = $this->mTrxWriteAdjQueryCount * $rtt;
$applyTime = max( $this->mTrxWriteAdjDuration - $rttAdjTotal, 0 );
// For omitted queries, make them count as something at least
$omitted = $this->mTrxWriteQueryCount - $this->mTrxWriteAdjQueryCount;
$applyTime += self::TINY_WRITE_SEC * $omitted;
return $applyTime;
default: // everything
return $this->mTrxWriteDuration;
}
}
public function pendingWriteCallers() {
return $this->mTrxLevel ? $this->mTrxWriteCallers : [];
}
public function isOpen() {
return $this->mOpened;
}
public function setFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
if ( $remember === self::REMEMBER_PRIOR ) {
array_push( $this->priorFlags, $this->mFlags );
}
$this->mFlags |= $flag;
}
public function clearFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
if ( $remember === self::REMEMBER_PRIOR ) {
array_push( $this->priorFlags, $this->mFlags );
}
$this->mFlags &= ~$flag;
}
public function restoreFlags( $state = self::RESTORE_PRIOR ) {
if ( !$this->priorFlags ) {
return;
}
if ( $state === self::RESTORE_INITIAL ) {
$this->mFlags = reset( $this->priorFlags );
$this->priorFlags = [];
} else {
$this->mFlags = array_pop( $this->priorFlags );
}
}
public function getFlag( $flag ) {
return !!( $this->mFlags & $flag );
}
public function getProperty( $name ) {
return $this->$name;
}
public function getWikiID() {
if ( $this->mTablePrefix ) {
return "{$this->mDBname}-{$this->mTablePrefix}";
} else {
return $this->mDBname;
}
}
/**
* Return a path to the DBMS-specific SQL file if it exists,
* otherwise default SQL file
*
* @param string $filename
* @return string
*/
private function getSqlFilePath( $filename ) {
global $IP;
$dbmsSpecificFilePath = "$IP/maintenance/" . $this->getType() . "/$filename";
if ( file_exists( $dbmsSpecificFilePath ) ) {
return $dbmsSpecificFilePath;
} else {
return "$IP/maintenance/$filename";
}
}
/**
* Return a path to the DBMS-specific schema file,
* otherwise default to tables.sql
*
* @return string
*/
public function getSchemaPath() {
return $this->getSqlFilePath( 'tables.sql' );
}
/**
* Return a path to the DBMS-specific update key file,
* otherwise default to update-keys.sql
*
* @return string
*/
public function getUpdateKeysPath() {
return $this->getSqlFilePath( 'update-keys.sql' );
}
/**
* Get information about an index into an object
* @param string $table Table name
* @param string $index Index name
* @param string $fname Calling function name
* @return mixed Database-specific index description class or false if the index does not exist
*/
abstract function indexInfo( $table, $index, $fname = __METHOD__ );
/**
* Wrapper for addslashes()
*
* @param string $s String to be slashed.
* @return string Slashed string.
*/
abstract function strencode( $s );
/**
* Constructor.
*
* FIXME: It is possible to construct a Database object with no associated
* connection object, by specifying no parameters to __construct(). This
* feature is deprecated and should be removed.
*
* DatabaseBase subclasses should not be constructed directly in external
* code. DatabaseBase::factory() should be used instead.
*
* @param array $params Parameters passed from DatabaseBase::factory()
*/
function __construct( array $params ) {
global $wgDBprefix, $wgDBmwschema, $wgCommandLineMode;
$this->srvCache = ObjectCache::getLocalServerInstance( 'hash' );
$server = $params['host'];
$user = $params['user'];
$password = $params['password'];
$dbName = $params['dbname'];
$flags = $params['flags'];
$tablePrefix = $params['tablePrefix'];
$schema = $params['schema'];
$foreign = $params['foreign'];
$this->mFlags = $flags;
if ( $this->mFlags & DBO_DEFAULT ) {
if ( $wgCommandLineMode ) {
$this->mFlags &= ~DBO_TRX;
} else {
$this->mFlags |= DBO_TRX;
}
}
$this->mSessionVars = $params['variables'];
/** Get the default table prefix*/
if ( $tablePrefix === 'get from global' ) {
$this->mTablePrefix = $wgDBprefix;
} else {
$this->mTablePrefix = $tablePrefix;
}
/** Get the database schema*/
if ( $schema === 'get from global' ) {
$this->mSchema = $wgDBmwschema;
} else {
$this->mSchema = $schema;
}
$this->mForeign = $foreign;
$this->profiler = isset( $params['profiler'] )
? $params['profiler']
: Profiler::instance(); // @TODO: remove global state
$this->trxProfiler = isset( $params['trxProfiler'] )
? $params['trxProfiler']
: new TransactionProfiler();
if ( $user ) {
$this->open( $server, $user, $password, $dbName );
}
}
/**
* Called by serialize. Throw an exception when DB connection is serialized.
* This causes problems on some database engines because the connection is
* not restored on unserialize.
*/
public function __sleep() {
throw new MWException( 'Database serialization may cause problems, since ' .
'the connection is not restored on wakeup.' );
}
/**
* Given a DB type, construct the name of the appropriate child class of
* DatabaseBase. This is designed to replace all of the manual stuff like:
* $class = 'Database' . ucfirst( strtolower( $dbType ) );
* as well as validate against the canonical list of DB types we have
*
* This factory function is mostly useful for when you need to connect to a
* database other than the MediaWiki default (such as for external auth,
* an extension, et cetera). Do not use this to connect to the MediaWiki
* database. Example uses in core:
* @see LoadBalancer::reallyOpenConnection()
* @see ForeignDBRepo::getMasterDB()
* @see WebInstallerDBConnect::execute()
*
* @since 1.18
*
* @param string $dbType A possible DB type
* @param array $p An array of options to pass to the constructor.
* Valid options are: host, user, password, dbname, flags, tablePrefix, schema, driver
* @throws MWException If the database driver or extension cannot be found
* @return DatabaseBase|null DatabaseBase subclass or null
*/
final public static function factory( $dbType, $p = [] ) {
$canonicalDBTypes = [
'mysql' => [ 'mysqli', 'mysql' ],
'postgres' => [],
'sqlite' => [],
'oracle' => [],
'mssql' => [],
];
$driver = false;
$dbType = strtolower( $dbType );
if ( isset( $canonicalDBTypes[$dbType] ) && $canonicalDBTypes[$dbType] ) {
$possibleDrivers = $canonicalDBTypes[$dbType];
if ( !empty( $p['driver'] ) ) {
if ( in_array( $p['driver'], $possibleDrivers ) ) {
$driver = $p['driver'];
} else {
throw new MWException( __METHOD__ .
" cannot construct Database with type '$dbType' and driver '{$p['driver']}'" );
}
} else {
foreach ( $possibleDrivers as $posDriver ) {
if ( extension_loaded( $posDriver ) ) {
$driver = $posDriver;
break;
}
}
}
} else {
$driver = $dbType;
}
if ( $driver === false ) {
throw new MWException( __METHOD__ .
" no viable database extension found for type '$dbType'" );
}
// Determine schema defaults. Currently Microsoft SQL Server uses $wgDBmwschema,
// and everything else doesn't use a schema (e.g. null)
// Although postgres and oracle support schemas, we don't use them (yet)
// to maintain backwards compatibility
$defaultSchemas = [
'mssql' => 'get from global',
];
$class = 'Database' . ucfirst( $driver );
if ( class_exists( $class ) && is_subclass_of( $class, 'DatabaseBase' ) ) {
// Resolve some defaults for b/c
$p['host'] = isset( $p['host'] ) ? $p['host'] : false;
$p['user'] = isset( $p['user'] ) ? $p['user'] : false;
$p['password'] = isset( $p['password'] ) ? $p['password'] : false;
$p['dbname'] = isset( $p['dbname'] ) ? $p['dbname'] : false;
$p['flags'] = isset( $p['flags'] ) ? $p['flags'] : 0;
$p['variables'] = isset( $p['variables'] ) ? $p['variables'] : [];
$p['tablePrefix'] = isset( $p['tablePrefix'] ) ? $p['tablePrefix'] : 'get from global';
if ( !isset( $p['schema'] ) ) {
$p['schema'] = isset( $defaultSchemas[$dbType] ) ? $defaultSchemas[$dbType] : null;
}
$p['foreign'] = isset( $p['foreign'] ) ? $p['foreign'] : false;
return new $class( $p );
} else {
return null;
}
}
protected function installErrorHandler() {
$this->mPHPError = false;
$this->htmlErrors = ini_set( 'html_errors', '0' );
set_error_handler( [ $this, 'connectionErrorHandler' ] );
}
/**
* @return bool|string
*/
protected function restoreErrorHandler() {
restore_error_handler();
if ( $this->htmlErrors !== false ) {
ini_set( 'html_errors', $this->htmlErrors );
}
if ( $this->mPHPError ) {
$error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError );
$error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
return $error;
} else {
return false;
}
}
/**
* @param int $errno
* @param string $errstr
*/
public function connectionErrorHandler( $errno, $errstr ) {
$this->mPHPError = $errstr;
}
/**
* Create a log context to pass to wfLogDBError or other logging functions.
*
* @param array $extras Additional data to add to context
* @return array
*/
protected function getLogContext( array $extras = [] ) {
return array_merge(
[
'db_server' => $this->mServer,
'db_name' => $this->mDBname,
'db_user' => $this->mUser,
],
$extras
);
}
public function close() {
if ( $this->mConn ) {
if ( $this->trxLevel() ) {
if ( !$this->mTrxAutomatic ) {
wfWarn( "Transaction still in progress (from {$this->mTrxFname}), " .
" performing implicit commit before closing connection!" );
}
$this->commit( __METHOD__, self::FLUSHING_INTERNAL );
}
$closed = $this->closeConnection();
$this->mConn = false;
} elseif ( $this->mTrxIdleCallbacks || $this->mTrxEndCallbacks ) { // sanity
throw new MWException( "Transaction callbacks still pending." );
} else {
$closed = true;
}
$this->mOpened = false;
return $closed;
}
/**
* Make sure isOpen() returns true as a sanity check
*
* @throws DBUnexpectedError
*/
protected function assertOpen() {
if ( !$this->isOpen() ) {
throw new DBUnexpectedError( $this, "DB connection was already closed." );
}
}
/**
* Closes underlying database connection
* @since 1.20
* @return bool Whether connection was closed successfully
*/
abstract protected function closeConnection();
function reportConnectionError( $error = 'Unknown error' ) {
$myError = $this->lastError();
if ( $myError ) {
$error = $myError;
}
# New method
throw new DBConnectionError( $this, $error );
}
/**
* The DBMS-dependent part of query()
*
* @param string $sql SQL query.
* @return ResultWrapper|bool Result object to feed to fetchObject,
* fetchRow, ...; or false on failure
*/
abstract protected function doQuery( $sql );
/**
* Determine whether a query writes to the DB.
* Should return true if unsure.
*
* @param string $sql
* @return bool
*/
protected function isWriteQuery( $sql ) {
return !preg_match(
'/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
}
/**
* @param $sql
* @return string|null
*/
protected function getQueryVerb( $sql ) {
return preg_match( '/^\s*([a-z]+)/i', $sql, $m ) ? strtoupper( $m[1] ) : null;
}
/**
* Determine whether a SQL statement is sensitive to isolation level.
* A SQL statement is considered transactable if its result could vary
* depending on the transaction isolation level. Operational commands
* such as 'SET' and 'SHOW' are not considered to be transactable.
*
* @param string $sql
* @return bool
*/
protected function isTransactableQuery( $sql ) {
$verb = $this->getQueryVerb( $sql );
return !in_array( $verb, [ 'BEGIN', 'COMMIT', 'ROLLBACK', 'SHOW', 'SET' ], true );
}
public function query( $sql, $fname = __METHOD__, $tempIgnore = false ) {
global $wgUser;
$priorWritesPending = $this->writesOrCallbacksPending();
$this->mLastQuery = $sql;
$isWrite = $this->isWriteQuery( $sql );
if ( $isWrite ) {
$reason = $this->getReadOnlyReason();
if ( $reason !== false ) {
throw new DBReadOnlyError( $this, "Database is read-only: $reason" );
}
# Set a flag indicating that writes have been done
$this->mDoneWrites = microtime( true );
}
# Add a comment for easy SHOW PROCESSLIST interpretation
if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
$userName = $wgUser->getName();
if ( mb_strlen( $userName ) > 15 ) {
$userName = mb_substr( $userName, 0, 15 ) . '...';
}
$userName = str_replace( '/', '', $userName );
} else {
$userName = '';
}
// Add trace comment to the begin of the sql string, right after the operator.
// Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (bug 42598)
$commentedSql = preg_replace( '/\s|$/', " /* $fname $userName */ ", $sql, 1 );
# Start implicit transactions that wrap the request if DBO_TRX is enabled
if ( !$this->mTrxLevel && $this->getFlag( DBO_TRX )
&& $this->isTransactableQuery( $sql )
) {
$this->begin( __METHOD__ . " ($fname)", self::TRANSACTION_INTERNAL );
$this->mTrxAutomatic = true;
}
# Keep track of whether the transaction has write queries pending
if ( $this->mTrxLevel && !$this->mTrxDoneWrites && $isWrite ) {
$this->mTrxDoneWrites = true;
$this->getTransactionProfiler()->transactionWritingIn(
$this->mServer, $this->mDBname, $this->mTrxShortId );
}
if ( $this->debug() ) {
wfDebugLog( 'queries', sprintf( "%s: %s", $this->mDBname, $commentedSql ) );
}
# Avoid fatals if close() was called
$this->assertOpen();
# Send the query to the server
$ret = $this->doProfiledQuery( $sql, $commentedSql, $isWrite, $fname );
# Try reconnecting if the connection was lost
if ( false === $ret && $this->wasErrorReissuable() ) {
$recoverable = $this->canRecoverFromDisconnect( $sql, $priorWritesPending );
# Stash the last error values before anything might clear them
$lastError = $this->lastError();
$lastErrno = $this->lastErrno();
# Update state tracking to reflect transaction loss due to disconnection
$this->handleTransactionLoss();
wfDebug( "Connection lost, reconnecting...\n" );
if ( $this->reconnect() ) {
wfDebug( "Reconnected\n" );
$msg = __METHOD__ . ": lost connection to {$this->getServer()}; reconnected";
wfDebugLog( 'DBPerformance', "$msg:\n" . wfBacktrace( true ) );
if ( !$recoverable ) {
# Callers may catch the exception and continue to use the DB
$this->reportQueryError( $lastError, $lastErrno, $sql, $fname );
} else {
# Should be safe to silently retry the query
$ret = $this->doProfiledQuery( $sql, $commentedSql, $isWrite, $fname );
}
} else {
wfDebug( "Failed\n" );
}
}
if ( false === $ret ) {
# Deadlocks cause the entire transaction to abort, not just the statement.
# http://dev.mysql.com/doc/refman/5.7/en/innodb-error-handling.html
# https://www.postgresql.org/docs/9.1/static/explicit-locking.html
if ( $this->wasDeadlock() ) {
if ( $this->explicitTrxActive() || $priorWritesPending ) {
$tempIgnore = false; // not recoverable
}
# Update state tracking to reflect transaction loss
$this->handleTransactionLoss();
}
$this->reportQueryError(
$this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
}
$res = $this->resultObject( $ret );
return $res;
}
private function doProfiledQuery( $sql, $commentedSql, $isWrite, $fname ) {
$isMaster = !is_null( $this->getLBInfo( 'master' ) );
# generalizeSQL() will probably cut down the query to reasonable
# logging size most of the time. The substr is really just a sanity check.
if ( $isMaster ) {
$queryProf = 'query-m: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
} else {
$queryProf = 'query: ' . substr( DatabaseBase::generalizeSQL( $sql ), 0, 255 );
}
# Include query transaction state
$queryProf .= $this->mTrxShortId ? " [TRX#{$this->mTrxShortId}]" : "";
$startTime = microtime( true );
$this->profiler->profileIn( $queryProf );
$ret = $this->doQuery( $commentedSql );
$this->profiler->profileOut( $queryProf );
$queryRuntime = max( microtime( true ) - $startTime, 0.0 );
unset( $queryProfSection ); // profile out (if set)
if ( $ret !== false ) {
$this->lastPing = $startTime;
if ( $isWrite && $this->mTrxLevel ) {
$this->updateTrxWriteQueryTime( $sql, $queryRuntime );
$this->mTrxWriteCallers[] = $fname;
}
}
if ( $sql === self::PING_QUERY ) {
$this->mRTTEstimate = $queryRuntime;
}
$this->getTransactionProfiler()->recordQueryCompletion(
$queryProf, $startTime, $isWrite, $this->affectedRows()
);
MWDebug::query( $sql, $fname, $isMaster, $queryRuntime );
return $ret;
}
/**
* Update the estimated run-time of a query, not counting large row lock times
*
* LoadBalancer can be set to rollback transactions that will create huge replication
* lag. It bases this estimate off of pendingWriteQueryDuration(). Certain simple
* queries, like inserting a row can take a long time due to row locking. This method
* uses some simple heuristics to discount those cases.
*
* @param string $sql
* @param float $runtime Total runtime, including RTT
*/
private function updateTrxWriteQueryTime( $sql, $runtime ) {
$indicativeOfSlaveRuntime = true;
if ( $runtime > self::SLOW_WRITE_SEC ) {
$verb = $this->getQueryVerb( $sql );
// insert(), upsert(), replace() are fast unless bulky in size or blocked on locks
if ( $verb === 'INSERT' ) {
$indicativeOfSlaveRuntime = $this->affectedRows() > self::SMALL_WRITE_ROWS;
} elseif ( $verb === 'REPLACE' ) {
$indicativeOfSlaveRuntime = $this->affectedRows() > self::SMALL_WRITE_ROWS / 2;
}
}
$this->mTrxWriteDuration += $runtime;
$this->mTrxWriteQueryCount += 1;
if ( $indicativeOfSlaveRuntime ) {
$this->mTrxWriteAdjDuration += $runtime;
$this->mTrxWriteAdjQueryCount += 1;
}
}
private function canRecoverFromDisconnect( $sql, $priorWritesPending ) {
# Transaction dropped; this can mean lost writes, or REPEATABLE-READ snapshots.
# Dropped connections also mean that named locks are automatically released.
# Only allow error suppression in autocommit mode or when the lost transaction
# didn't matter anyway (aside from DBO_TRX snapshot loss).
if ( $this->mNamedLocksHeld ) {
return false; // possible critical section violation
} elseif ( $sql === 'COMMIT' ) {
return !$priorWritesPending; // nothing written anyway? (T127428)
} elseif ( $sql === 'ROLLBACK' ) {
return true; // transaction lost...which is also what was requested :)
} elseif ( $this->explicitTrxActive() ) {
return false; // don't drop atomocity
} elseif ( $priorWritesPending ) {
return false; // prior writes lost from implicit transaction
}
return true;
}
private function handleTransactionLoss() {
$this->mTrxLevel = 0;
$this->mTrxIdleCallbacks = []; // bug 65263
$this->mTrxPreCommitCallbacks = []; // bug 65263
try {
// Handle callbacks in mTrxEndCallbacks
$this->runOnTransactionIdleCallbacks( self::TRIGGER_ROLLBACK );
$this->runTransactionListenerCallbacks( self::TRIGGER_ROLLBACK );
return null;
} catch ( Exception $e ) {
// Already logged; move on...
return $e;
}
}
public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
if ( $this->ignoreErrors() || $tempIgnore ) {
wfDebug( "SQL ERROR (ignored): $error\n" );
} else {
$sql1line = mb_substr( str_replace( "\n", "\\n", $sql ), 0, 5 * 1024 );
wfLogDBError(
"{fname}\t{db_server}\t{errno}\t{error}\t{sql1line}",
$this->getLogContext( [
'method' => __METHOD__,
'errno' => $errno,
'error' => $error,
'sql1line' => $sql1line,
'fname' => $fname,
] )
);
wfDebug( "SQL ERROR: " . $error . "\n" );
throw new DBQueryError( $this, $error, $errno, $sql, $fname );
}
}
/**
* Intended to be compatible with the PEAR::DB wrapper functions.
* http://pear.php.net/manual/en/package.database.db.intro-execute.php
*
* ? = scalar value, quoted as necessary
* ! = raw SQL bit (a function for instance)
* & = filename; reads the file and inserts as a blob
* (we don't use this though...)
*
* @param string $sql
* @param string $func
*
* @return array
*/
protected function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
/* MySQL doesn't support prepared statements (yet), so just
* pack up the query for reference. We'll manually replace
* the bits later.
*/
return [ 'query' => $sql, 'func' => $func ];
}
/**
* Free a prepared query, generated by prepare().
* @param string $prepared
*/
protected function freePrepared( $prepared ) {
/* No-op by default */
}
/**
* Execute a prepared query with the various arguments
* @param string $prepared The prepared sql
* @param mixed $args Either an array here, or put scalars as varargs
*
* @return ResultWrapper
*/
public function execute( $prepared, $args = null ) {
if ( !is_array( $args ) ) {
# Pull the var args
$args = func_get_args();
array_shift( $args );
}
$sql = $this->fillPrepared( $prepared['query'], $args );
return $this->query( $sql, $prepared['func'] );
}
/**
* For faking prepared SQL statements on DBs that don't support it directly.
*
* @param string $preparedQuery A 'preparable' SQL statement
* @param array $args Array of Arguments to fill it with
* @return string Executable SQL
*/
public function fillPrepared( $preparedQuery, $args ) {
reset( $args );
$this->preparedArgs =& $args;
return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
[ &$this, 'fillPreparedArg' ], $preparedQuery );
}
/**
* preg_callback func for fillPrepared()
* The arguments should be in $this->preparedArgs and must not be touched
* while we're doing this.
*
* @param array $matches
* @throws DBUnexpectedError
* @return string
*/
protected function fillPreparedArg( $matches ) {
switch ( $matches[1] ) {
case '\\?':
return '?';
case '\\!':
return '!';
case '\\&':
return '&';
}
list( /* $n */, $arg ) = each( $this->preparedArgs );
switch ( $matches[1] ) {
case '?':
return $this->addQuotes( $arg );
case '!':
return $arg;
case '&':
# return $this->addQuotes( file_get_contents( $arg ) );
throw new DBUnexpectedError(
$this,
'& mode is not implemented. If it\'s really needed, uncomment the line above.'
);
default:
throw new DBUnexpectedError(
$this,
'Received invalid match. This should never happen!'
);
}
}
public function freeResult( $res ) {
}
public function selectField(
$table, $var, $cond = '', $fname = __METHOD__, $options = []
) {
if ( $var === '*' ) { // sanity
throw new DBUnexpectedError( $this, "Cannot use a * field: got '$var'" );
}
if ( !is_array( $options ) ) {
$options = [ $options ];
}
$options['LIMIT'] = 1;
$res = $this->select( $table, $var, $cond, $fname, $options );
if ( $res === false || !$this->numRows( $res ) ) {
return false;
}
$row = $this->fetchRow( $res );
if ( $row !== false ) {
return reset( $row );
} else {
return false;
}
}
public function selectFieldValues(
$table, $var, $cond = '', $fname = __METHOD__, $options = [], $join_conds = []
) {
if ( $var === '*' ) { // sanity
throw new DBUnexpectedError( $this, "Cannot use a * field" );
} elseif ( !is_string( $var ) ) { // sanity
throw new DBUnexpectedError( $this, "Cannot use an array of fields" );
}
if ( !is_array( $options ) ) {
$options = [ $options ];
}
$res = $this->select( $table, $var, $cond, $fname, $options, $join_conds );
if ( $res === false ) {
return false;
}
$values = [];
foreach ( $res as $row ) {
$values[] = $row->$var;
}
return $values;
}
/**
* Returns an optional USE INDEX clause to go after the table, and a
* string to go at the end of the query.
*
* @param array $options Associative array of options to be turned into
* an SQL query, valid keys are listed in the function.
* @return array
* @see DatabaseBase::select()
*/
public function makeSelectOptions( $options ) {
$preLimitTail = $postLimitTail = '';
$startOpts = '';
$noKeyOptions = [];
foreach ( $options as $key => $option ) {
if ( is_numeric( $key ) ) {
$noKeyOptions[$option] = true;
}
}
$preLimitTail .= $this->makeGroupByWithHaving( $options );
$preLimitTail .= $this->makeOrderBy( $options );
// if (isset($options['LIMIT'])) {
// $tailOpts .= $this->limitResult('', $options['LIMIT'],
// isset($options['OFFSET']) ? $options['OFFSET']
// : false);
// }
if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
$postLimitTail .= ' FOR UPDATE';
}
if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
$postLimitTail .= ' LOCK IN SHARE MODE';
}
if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
$startOpts .= 'DISTINCT';
}
# Various MySQL extensions
if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
$startOpts .= ' /*! STRAIGHT_JOIN */';
}
if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
$startOpts .= ' HIGH_PRIORITY';
}
if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
$startOpts .= ' SQL_BIG_RESULT';
}
if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
$startOpts .= ' SQL_BUFFER_RESULT';
}
if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
$startOpts .= ' SQL_SMALL_RESULT';
}
if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
$startOpts .= ' SQL_CALC_FOUND_ROWS';
}
if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
$startOpts .= ' SQL_CACHE';
}
if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
$startOpts .= ' SQL_NO_CACHE';
}
if ( isset( $options['USE INDEX'] ) && is_string( $options['USE INDEX'] ) ) {
$useIndex = $this->useIndexClause( $options['USE INDEX'] );
} else {
$useIndex = '';
}
return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail ];
}
/**
* Returns an optional GROUP BY with an optional HAVING
*
* @param array $options Associative array of options
* @return string
* @see DatabaseBase::select()
* @since 1.21
*/
public function makeGroupByWithHaving( $options ) {
$sql = '';
if ( isset( $options['GROUP BY'] ) ) {
$gb = is_array( $options['GROUP BY'] )
? implode( ',', $options['GROUP BY'] )
: $options['GROUP BY'];
$sql .= ' GROUP BY ' . $gb;
}
if ( isset( $options['HAVING'] ) ) {
$having = is_array( $options['HAVING'] )
? $this->makeList( $options['HAVING'], LIST_AND )
: $options['HAVING'];
$sql .= ' HAVING ' . $having;
}
return $sql;
}
/**
* Returns an optional ORDER BY
*
* @param array $options Associative array of options
* @return string
* @see DatabaseBase::select()
* @since 1.21
*/
public function makeOrderBy( $options ) {
if ( isset( $options['ORDER BY'] ) ) {
$ob = is_array( $options['ORDER BY'] )
? implode( ',', $options['ORDER BY'] )
: $options['ORDER BY'];
return ' ORDER BY ' . $ob;
}
return '';
}
// See IDatabase::select for the docs for this function
public function select( $table, $vars, $conds = '', $fname = __METHOD__,
$options = [], $join_conds = [] ) {
$sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
return $this->query( $sql, $fname );
}
public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__,
$options = [], $join_conds = []
) {
if ( is_array( $vars ) ) {
$vars = implode( ',', $this->fieldNamesWithAlias( $vars ) );
}
$options = (array)$options;
$useIndexes = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
? $options['USE INDEX']
: [];
if ( is_array( $table ) ) {
$from = ' FROM ' .
$this->tableNamesWithUseIndexOrJOIN( $table, $useIndexes, $join_conds );
} elseif ( $table != '' ) {
if ( $table[0] == ' ' ) {
$from = ' FROM ' . $table;
} else {
$from = ' FROM ' .
$this->tableNamesWithUseIndexOrJOIN( [ $table ], $useIndexes, [] );
}
} else {
$from = '';
}
list( $startOpts, $useIndex, $preLimitTail, $postLimitTail ) =
$this->makeSelectOptions( $options );
if ( !empty( $conds ) ) {
if ( is_array( $conds ) ) {
$conds = $this->makeList( $conds, LIST_AND );
}
$sql = "SELECT $startOpts $vars $from $useIndex WHERE $conds $preLimitTail";
} else {
$sql = "SELECT $startOpts $vars $from $useIndex $preLimitTail";
}
if ( isset( $options['LIMIT'] ) ) {
$sql = $this->limitResult( $sql, $options['LIMIT'],
isset( $options['OFFSET'] ) ? $options['OFFSET'] : false );
}
$sql = "$sql $postLimitTail";
if ( isset( $options['EXPLAIN'] ) ) {
$sql = 'EXPLAIN ' . $sql;
}
return $sql;
}
public function selectRow( $table, $vars, $conds, $fname = __METHOD__,
$options = [], $join_conds = []
) {
$options = (array)$options;
$options['LIMIT'] = 1;
$res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
if ( $res === false ) {
return false;
}
if ( !$this->numRows( $res ) ) {
return false;
}
$obj = $this->fetchObject( $res );
return $obj;
}
public function estimateRowCount(
$table, $vars = '*', $conds = '', $fname = __METHOD__, $options = []
) {
$rows = 0;
$res = $this->select( $table, [ 'rowcount' => 'COUNT(*)' ], $conds, $fname, $options );
if ( $res ) {
$row = $this->fetchRow( $res );
$rows = ( isset( $row['rowcount'] ) ) ? (int)$row['rowcount'] : 0;
}
return $rows;
}
public function selectRowCount(
$tables, $vars = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
) {
$rows = 0;
$sql = $this->selectSQLText( $tables, '1', $conds, $fname, $options, $join_conds );
$res = $this->query( "SELECT COUNT(*) AS rowcount FROM ($sql) tmp_count", $fname );
if ( $res ) {
$row = $this->fetchRow( $res );
$rows = ( isset( $row['rowcount'] ) ) ? (int)$row['rowcount'] : 0;
}
return $rows;
}
/**
* Removes most variables from an SQL query and replaces them with X or N for numbers.
* It's only slightly flawed. Don't use for anything important.
*
* @param string $sql A SQL Query
*
* @return string
*/
protected static function generalizeSQL( $sql ) {
# This does the same as the regexp below would do, but in such a way
# as to avoid crashing php on some large strings.
# $sql = preg_replace( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql );
$sql = str_replace( "\\\\", '', $sql );
$sql = str_replace( "\\'", '', $sql );
$sql = str_replace( "\\\"", '', $sql );
$sql = preg_replace( "/'.*'/s", "'X'", $sql );
$sql = preg_replace( '/".*"/s', "'X'", $sql );
# All newlines, tabs, etc replaced by single space
$sql = preg_replace( '/\s+/', ' ', $sql );
# All numbers => N,
# except the ones surrounded by characters, e.g. l10n
$sql = preg_replace( '/-?\d+(,-?\d+)+/s', 'N,...,N', $sql );
$sql = preg_replace( '/(?<![a-zA-Z])-?\d+(?![a-zA-Z])/s', 'N', $sql );
return $sql;
}
public function fieldExists( $table, $field, $fname = __METHOD__ ) {
$info = $this->fieldInfo( $table, $field );
return (bool)$info;
}
public function indexExists( $table, $index, $fname = __METHOD__ ) {
if ( !$this->tableExists( $table ) ) {
return null;
}
$info = $this->indexInfo( $table, $index, $fname );
if ( is_null( $info ) ) {
return null;
} else {
return $info !== false;
}
}
public function tableExists( $table, $fname = __METHOD__ ) {
$table = $this->tableName( $table );
$old = $this->ignoreErrors( true );
$res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname );
$this->ignoreErrors( $old );
return (bool)$res;
}
public function indexUnique( $table, $index ) {
$indexInfo = $this->indexInfo( $table, $index );
if ( !$indexInfo ) {
return null;
}
return !$indexInfo[0]->Non_unique;
}
/**
* Helper for DatabaseBase::insert().
*
* @param array $options
* @return string
*/
protected function makeInsertOptions( $options ) {
return implode( ' ', $options );
}
public function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
# No rows to insert, easy just return now
if ( !count( $a ) ) {
return true;
}
$table = $this->tableName( $table );
if ( !is_array( $options ) ) {
$options = [ $options ];
}
$fh = null;
if ( isset( $options['fileHandle'] ) ) {
$fh = $options['fileHandle'];
}
$options = $this->makeInsertOptions( $options );
if ( isset( $a[0] ) && is_array( $a[0] ) ) {
$multi = true;
$keys = array_keys( $a[0] );
} else {
$multi = false;
$keys = array_keys( $a );
}
$sql = 'INSERT ' . $options .
" INTO $table (" . implode( ',', $keys ) . ') VALUES ';
if ( $multi ) {
$first = true;
foreach ( $a as $row ) {
if ( $first ) {
$first = false;
} else {
$sql .= ',';
}
$sql .= '(' . $this->makeList( $row ) . ')';
}
} else {
$sql .= '(' . $this->makeList( $a ) . ')';
}
if ( $fh !== null && false === fwrite( $fh, $sql ) ) {
return false;
} elseif ( $fh !== null ) {
return true;
}
return (bool)$this->query( $sql, $fname );
}
/**
* Make UPDATE options array for DatabaseBase::makeUpdateOptions
*
* @param array $options
* @return array
*/
protected function makeUpdateOptionsArray( $options ) {
if ( !is_array( $options ) ) {
$options = [ $options ];
}
$opts = [];
if ( in_array( 'LOW_PRIORITY', $options ) ) {
$opts[] = $this->lowPriorityOption();
}
if ( in_array( 'IGNORE', $options ) ) {
$opts[] = 'IGNORE';
}
return $opts;
}
/**
* Make UPDATE options for the DatabaseBase::update function
*
* @param array $options The options passed to DatabaseBase::update
* @return string
*/
protected function makeUpdateOptions( $options ) {
$opts = $this->makeUpdateOptionsArray( $options );
return implode( ' ', $opts );
}
function update( $table, $values, $conds, $fname = __METHOD__, $options = [] ) {
$table = $this->tableName( $table );
$opts = $this->makeUpdateOptions( $options );
$sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET );
if ( $conds !== [] && $conds !== '*' ) {
$sql .= " WHERE " . $this->makeList( $conds, LIST_AND );
}
return $this->query( $sql, $fname );
}
public function makeList( $a, $mode = LIST_COMMA ) {
if ( !is_array( $a ) ) {
throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
}
$first = true;
$list = '';
foreach ( $a as $field => $value ) {
if ( !$first ) {
if ( $mode == LIST_AND ) {
$list .= ' AND ';
} elseif ( $mode == LIST_OR ) {
$list .= ' OR ';
} else {
$list .= ',';
}
} else {
$first = false;
}
if ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_numeric( $field ) ) {
$list .= "($value)";
} elseif ( ( $mode == LIST_SET ) && is_numeric( $field ) ) {
$list .= "$value";
} elseif ( ( $mode == LIST_AND || $mode == LIST_OR ) && is_array( $value ) ) {
// Remove null from array to be handled separately if found
$includeNull = false;
foreach ( array_keys( $value, null, true ) as $nullKey ) {
$includeNull = true;
unset( $value[$nullKey] );
}
if ( count( $value ) == 0 && !$includeNull ) {
throw new MWException( __METHOD__ . ": empty input for field $field" );
} elseif ( count( $value ) == 0 ) {
// only check if $field is null
$list .= "$field IS NULL";
} else {
// IN clause contains at least one valid element
if ( $includeNull ) {
// Group subconditions to ensure correct precedence
$list .= '(';
}
if ( count( $value ) == 1 ) {
// Special-case single values, as IN isn't terribly efficient
// Don't necessarily assume the single key is 0; we don't
// enforce linear numeric ordering on other arrays here.
$value = array_values( $value )[0];
$list .= $field . " = " . $this->addQuotes( $value );
} else {
$list .= $field . " IN (" . $this->makeList( $value ) . ") ";
}
// if null present in array, append IS NULL
if ( $includeNull ) {
$list .= " OR $field IS NULL)";
}
}
} elseif ( $value === null ) {
if ( $mode == LIST_AND || $mode == LIST_OR ) {
$list .= "$field IS ";
} elseif ( $mode == LIST_SET ) {
$list .= "$field = ";
}
$list .= 'NULL';
} else {
if ( $mode == LIST_AND || $mode == LIST_OR || $mode == LIST_SET ) {
$list .= "$field = ";
}
$list .= $mode == LIST_NAMES ? $value : $this->addQuotes( $value );
}
}
return $list;
}
public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
$conds = [];
foreach ( $data as $base => $sub ) {
if ( count( $sub ) ) {
$conds[] = $this->makeList(
[ $baseKey => $base, $subKey => array_keys( $sub ) ],
LIST_AND );
}
}
if ( $conds ) {
return $this->makeList( $conds, LIST_OR );
} else {
// Nothing to search for...
return false;
}
}
/**
* Return aggregated value alias
*
* @param array $valuedata
* @param string $valuename
*
* @return string
*/
public function aggregateValue( $valuedata, $valuename = 'value' ) {
return $valuename;
}
public function bitNot( $field ) {
return "(~$field)";
}
public function bitAnd( $fieldLeft, $fieldRight ) {
return "($fieldLeft & $fieldRight)";
}
public function bitOr( $fieldLeft, $fieldRight ) {
return "($fieldLeft | $fieldRight)";
}
public function buildConcat( $stringList ) {
return 'CONCAT(' . implode( ',', $stringList ) . ')';
}
public function buildGroupConcatField(
$delim, $table, $field, $conds = '', $join_conds = []
) {
$fld = "GROUP_CONCAT($field SEPARATOR " . $this->addQuotes( $delim ) . ')';
return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
}
public function selectDB( $db ) {
# Stub. Shouldn't cause serious problems if it's not overridden, but
# if your database engine supports a concept similar to MySQL's
# databases you may as well.
$this->mDBname = $db;
return true;
}
public function getDBname() {
return $this->mDBname;
}
public function getServer() {
return $this->mServer;
}
/**
* Format a table name ready for use in constructing an SQL query
*
* This does two important things: it quotes the table names to clean them up,
* and it adds a table prefix if only given a table name with no quotes.
*
* All functions of this object which require a table name call this function
* themselves. Pass the canonical name to such functions. This is only needed
* when calling query() directly.
*
* @note This function does not sanitize user input. It is not safe to use
* this function to escape user input.
* @param string $name Database table name
* @param string $format One of:
* quoted - Automatically pass the table name through addIdentifierQuotes()
* so that it can be used in a query.
* raw - Do not add identifier quotes to the table name
* @return string Full database name
*/
public function tableName( $name, $format = 'quoted' ) {
global $wgSharedDB, $wgSharedPrefix, $wgSharedTables, $wgSharedSchema;
# Skip the entire process when we have a string quoted on both ends.
# Note that we check the end so that we will still quote any use of
# use of `database`.table. But won't break things if someone wants
# to query a database table with a dot in the name.
if ( $this->isQuotedIdentifier( $name ) ) {
return $name;
}
# Lets test for any bits of text that should never show up in a table
# name. Basically anything like JOIN or ON which are actually part of
# SQL queries, but may end up inside of the table value to combine
# sql. Such as how the API is doing.
# Note that we use a whitespace test rather than a \b test to avoid
# any remote case where a word like on may be inside of a table name
# surrounded by symbols which may be considered word breaks.
if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
return $name;
}
# Split database and table into proper variables.
# We reverse the explode so that database.table and table both output
# the correct table.
$dbDetails = explode( '.', $name, 3 );
if ( count( $dbDetails ) == 3 ) {
list( $database, $schema, $table ) = $dbDetails;
# We don't want any prefix added in this case
$prefix = '';
} elseif ( count( $dbDetails ) == 2 ) {
list( $database, $table ) = $dbDetails;
# We don't want any prefix added in this case
# In dbs that support it, $database may actually be the schema
# but that doesn't affect any of the functionality here
$prefix = '';
$schema = null;
} else {
list( $table ) = $dbDetails;
if ( $wgSharedDB !== null # We have a shared database
&& $this->mForeign == false # We're not working on a foreign database
&& !$this->isQuotedIdentifier( $table ) # Prevent shared tables listing '`table`'
&& in_array( $table, $wgSharedTables ) # A shared table is selected
) {
$database = $wgSharedDB;
$schema = $wgSharedSchema === null ? $this->mSchema : $wgSharedSchema;
$prefix = $wgSharedPrefix === null ? $this->mTablePrefix : $wgSharedPrefix;
} else {
$database = null;
$schema = $this->mSchema; # Default schema
$prefix = $this->mTablePrefix; # Default prefix
}
}
# Quote $table and apply the prefix if not quoted.
# $tableName might be empty if this is called from Database::replaceVars()
$tableName = "{$prefix}{$table}";
if ( $format == 'quoted' && !$this->isQuotedIdentifier( $tableName ) && $tableName !== '' ) {
$tableName = $this->addIdentifierQuotes( $tableName );
}
# Quote $schema and merge it with the table name if needed
if ( strlen( $schema ) ) {
if ( $format == 'quoted' && !$this->isQuotedIdentifier( $schema ) ) {
$schema = $this->addIdentifierQuotes( $schema );
}
$tableName = $schema . '.' . $tableName;
}
# Quote $database and merge it with the table name if needed
if ( $database !== null ) {
if ( $format == 'quoted' && !$this->isQuotedIdentifier( $database ) ) {
$database = $this->addIdentifierQuotes( $database );
}
$tableName = $database . '.' . $tableName;
}
return $tableName;
}
/**
* Fetch a number of table names into an array
* This is handy when you need to construct SQL for joins
*
* Example:
* extract( $dbr->tableNames( 'user', 'watchlist' ) );
* $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
* WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
*
* @return array
*/
public function tableNames() {
$inArray = func_get_args();
$retVal = [];
foreach ( $inArray as $name ) {
$retVal[$name] = $this->tableName( $name );
}
return $retVal;
}
/**
* Fetch a number of table names into an zero-indexed numerical array
* This is handy when you need to construct SQL for joins
*
* Example:
* list( $user, $watchlist ) = $dbr->tableNamesN( 'user', 'watchlist' );
* $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
* WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
*
* @return array
*/
public function tableNamesN() {
$inArray = func_get_args();
$retVal = [];
foreach ( $inArray as $name ) {
$retVal[] = $this->tableName( $name );
}
return $retVal;
}
/**
* Get an aliased table name
* e.g. tableName AS newTableName
*
* @param string $name Table name, see tableName()
* @param string|bool $alias Alias (optional)
* @return string SQL name for aliased table. Will not alias a table to its own name
*/
public function tableNameWithAlias( $name, $alias = false ) {
if ( !$alias || $alias == $name ) {
return $this->tableName( $name );
} else {
return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
}
}
/**
* Gets an array of aliased table names
*
* @param array $tables [ [alias] => table ]
* @return string[] See tableNameWithAlias()
*/
public function tableNamesWithAlias( $tables ) {
$retval = [];
foreach ( $tables as $alias => $table ) {
if ( is_numeric( $alias ) ) {
$alias = $table;
}
$retval[] = $this->tableNameWithAlias( $table, $alias );
}
return $retval;
}
/**
* Get an aliased field name
* e.g. fieldName AS newFieldName
*
* @param string $name Field name
* @param string|bool $alias Alias (optional)
* @return string SQL name for aliased field. Will not alias a field to its own name
*/
public function fieldNameWithAlias( $name, $alias = false ) {
if ( !$alias || (string)$alias === (string)$name ) {
return $name;
} else {
return $name . ' AS ' . $this->addIdentifierQuotes( $alias ); // PostgreSQL needs AS
}
}
/**
* Gets an array of aliased field names
*
* @param array $fields [ [alias] => field ]
* @return string[] See fieldNameWithAlias()
*/
public function fieldNamesWithAlias( $fields ) {
$retval = [];
foreach ( $fields as $alias => $field ) {
if ( is_numeric( $alias ) ) {
$alias = $field;
}
$retval[] = $this->fieldNameWithAlias( $field, $alias );
}
return $retval;
}
/**
* Get the aliased table name clause for a FROM clause
* which might have a JOIN and/or USE INDEX clause
*
* @param array $tables ( [alias] => table )
* @param array $use_index Same as for select()
* @param array $join_conds Same as for select()
* @return string
*/
protected function tableNamesWithUseIndexOrJOIN(
$tables, $use_index = [], $join_conds = []
) {
$ret = [];
$retJOIN = [];
$use_index = (array)$use_index;
$join_conds = (array)$join_conds;
foreach ( $tables as $alias => $table ) {
if ( !is_string( $alias ) ) {
// No alias? Set it equal to the table name
$alias = $table;
}
// Is there a JOIN clause for this table?
if ( isset( $join_conds[$alias] ) ) {
list( $joinType, $conds ) = $join_conds[$alias];
$tableClause = $joinType;
$tableClause .= ' ' . $this->tableNameWithAlias( $table, $alias );
if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
$use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
if ( $use != '' ) {
$tableClause .= ' ' . $use;
}
}
$on = $this->makeList( (array)$conds, LIST_AND );
if ( $on != '' ) {
$tableClause .= ' ON (' . $on . ')';
}
$retJOIN[] = $tableClause;
} elseif ( isset( $use_index[$alias] ) ) {
// Is there an INDEX clause for this table?
$tableClause = $this->tableNameWithAlias( $table, $alias );
$tableClause .= ' ' . $this->useIndexClause(
implode( ',', (array)$use_index[$alias] )
);
$ret[] = $tableClause;
} else {
$tableClause = $this->tableNameWithAlias( $table, $alias );
$ret[] = $tableClause;
}
}
// We can't separate explicit JOIN clauses with ',', use ' ' for those
$implicitJoins = !empty( $ret ) ? implode( ',', $ret ) : "";
$explicitJoins = !empty( $retJOIN ) ? implode( ' ', $retJOIN ) : "";
// Compile our final table clause
return implode( ' ', [ $implicitJoins, $explicitJoins ] );
}
/**
* Get the name of an index in a given table.
*
* @param string $index
* @return string
*/
protected function indexName( $index ) {
// Backwards-compatibility hack
$renamed = [
'ar_usertext_timestamp' => 'usertext_timestamp',
'un_user_id' => 'user_id',
'un_user_ip' => 'user_ip',
];
if ( isset( $renamed[$index] ) ) {
return $renamed[$index];
} else {
return $index;
}
}
public function addQuotes( $s ) {
if ( $s instanceof Blob ) {
$s = $s->fetch();
}
if ( $s === null ) {
return 'NULL';
} else {
# This will also quote numeric values. This should be harmless,
# and protects against weird problems that occur when they really
# _are_ strings such as article titles and string->number->string
# conversion is not 1:1.
return "'" . $this->strencode( $s ) . "'";
}
}
/**
* Quotes an identifier using `backticks` or "double quotes" depending on the database type.
* MySQL uses `backticks` while basically everything else uses double quotes.
* Since MySQL is the odd one out here the double quotes are our generic
* and we implement backticks in DatabaseMysql.
*
* @param string $s
* @return string
*/
public function addIdentifierQuotes( $s ) {
return '"' . str_replace( '"', '""', $s ) . '"';
}
/**
* Returns if the given identifier looks quoted or not according to
* the database convention for quoting identifiers .
*
* @note Do not use this to determine if untrusted input is safe.
* A malicious user can trick this function.
* @param string $name
* @return bool
*/
public function isQuotedIdentifier( $name ) {
return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
}
/**
* @param string $s
* @return string
*/
protected function escapeLikeInternal( $s ) {
return addcslashes( $s, '\%_' );
}
public function buildLike() {
$params = func_get_args();
if ( count( $params ) > 0 && is_array( $params[0] ) ) {
$params = $params[0];
}
$s = '';
foreach ( $params as $value ) {
if ( $value instanceof LikeMatch ) {
$s .= $value->toString();
} else {
$s .= $this->escapeLikeInternal( $value );
}
}
return " LIKE {$this->addQuotes( $s )} ";
}
public function anyChar() {
return new LikeMatch( '_' );
}
public function anyString() {
return new LikeMatch( '%' );
}
public function nextSequenceValue( $seqName ) {
return null;
}
/**
* USE INDEX clause. Unlikely to be useful for anything but MySQL. This
* is only needed because a) MySQL must be as efficient as possible due to
* its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
* which index to pick. Anyway, other databases might have different
* indexes on a given table. So don't bother overriding this unless you're
* MySQL.
* @param string $index
* @return string
*/
public function useIndexClause( $index ) {
return '';
}
public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
$quotedTable = $this->tableName( $table );
if ( count( $rows ) == 0 ) {
return;
}
# Single row case
if ( !is_array( reset( $rows ) ) ) {
$rows = [ $rows ];
}
// @FXIME: this is not atomic, but a trx would break affectedRows()
foreach ( $rows as $row ) {
# Delete rows which collide
if ( $uniqueIndexes ) {
$sql = "DELETE FROM $quotedTable WHERE ";
$first = true;
foreach ( $uniqueIndexes as $index ) {
if ( $first ) {
$first = false;
$sql .= '( ';
} else {
$sql .= ' ) OR ( ';
}
if ( is_array( $index ) ) {
$first2 = true;
foreach ( $index as $col ) {
if ( $first2 ) {
$first2 = false;
} else {
$sql .= ' AND ';
}
$sql .= $col . '=' . $this->addQuotes( $row[$col] );
}
} else {
$sql .= $index . '=' . $this->addQuotes( $row[$index] );
}
}
$sql .= ' )';
$this->query( $sql, $fname );
}
# Now insert the row
$this->insert( $table, $row, $fname );
}
}
/**
* REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
* statement.
*
* @param string $table Table name
* @param array|string $rows Row(s) to insert
* @param string $fname Caller function name
*
* @return ResultWrapper
*/
protected function nativeReplace( $table, $rows, $fname ) {
$table = $this->tableName( $table );
# Single row case
if ( !is_array( reset( $rows ) ) ) {
$rows = [ $rows ];
}
$sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
$first = true;
foreach ( $rows as $row ) {
if ( $first ) {
$first = false;
} else {
$sql .= ',';
}
$sql .= '(' . $this->makeList( $row ) . ')';
}
return $this->query( $sql, $fname );
}
public function upsert( $table, array $rows, array $uniqueIndexes, array $set,
$fname = __METHOD__
) {
if ( !count( $rows ) ) {
return true; // nothing to do
}
if ( !is_array( reset( $rows ) ) ) {
$rows = [ $rows ];
}
if ( count( $uniqueIndexes ) ) {
$clauses = []; // list WHERE clauses that each identify a single row
foreach ( $rows as $row ) {
foreach ( $uniqueIndexes as $index ) {
$index = is_array( $index ) ? $index : [ $index ]; // columns
$rowKey = []; // unique key to this row
foreach ( $index as $column ) {
$rowKey[$column] = $row[$column];
}
$clauses[] = $this->makeList( $rowKey, LIST_AND );
}
}
$where = [ $this->makeList( $clauses, LIST_OR ) ];
} else {
$where = false;
}
$useTrx = !$this->mTrxLevel;
if ( $useTrx ) {
$this->begin( $fname, self::TRANSACTION_INTERNAL );
}
try {
# Update any existing conflicting row(s)
if ( $where !== false ) {
$ok = $this->update( $table, $set, $where, $fname );
} else {
$ok = true;
}
# Now insert any non-conflicting row(s)
$ok = $this->insert( $table, $rows, $fname, [ 'IGNORE' ] ) && $ok;
} catch ( Exception $e ) {
if ( $useTrx ) {
$this->rollback( $fname );
}
throw $e;
}
if ( $useTrx ) {
$this->commit( $fname, self::TRANSACTION_INTERNAL );
}
return $ok;
}
public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
$fname = __METHOD__
) {
if ( !$conds ) {
throw new DBUnexpectedError( $this,
'DatabaseBase::deleteJoin() called with empty $conds' );
}
$delTable = $this->tableName( $delTable );
$joinTable = $this->tableName( $joinTable );
$sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
if ( $conds != '*' ) {
$sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND );
}
$sql .= ')';
$this->query( $sql, $fname );
}
/**
* Returns the size of a text field, or -1 for "unlimited"
*
* @param string $table
* @param string $field
* @return int
*/
public function textFieldSize( $table, $field ) {
$table = $this->tableName( $table );
$sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
$res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
$row = $this->fetchObject( $res );
$m = [];
if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
$size = $m[1];
} else {
$size = -1;
}
return $size;
}
/**
* A string to insert into queries to show that they're low-priority, like
* MySQL's LOW_PRIORITY. If no such feature exists, return an empty
* string and nothing bad should happen.
*
* @return string Returns the text of the low priority option if it is
* supported, or a blank string otherwise
*/
public function lowPriorityOption() {
return '';
}
public function delete( $table, $conds, $fname = __METHOD__ ) {
if ( !$conds ) {
throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
}
$table = $this->tableName( $table );
$sql = "DELETE FROM $table";
if ( $conds != '*' ) {
if ( is_array( $conds ) ) {
$conds = $this->makeList( $conds, LIST_AND );
}
$sql .= ' WHERE ' . $conds;
}
return $this->query( $sql, $fname );
}
public function insertSelect( $destTable, $srcTable, $varMap, $conds,
$fname = __METHOD__,
$insertOptions = [], $selectOptions = []
) {
$destTable = $this->tableName( $destTable );
if ( !is_array( $insertOptions ) ) {
$insertOptions = [ $insertOptions ];
}
$insertOptions = $this->makeInsertOptions( $insertOptions );
if ( !is_array( $selectOptions ) ) {
$selectOptions = [ $selectOptions ];
}
list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
if ( is_array( $srcTable ) ) {
$srcTable = implode( ',', array_map( [ &$this, 'tableName' ], $srcTable ) );
} else {
$srcTable = $this->tableName( $srcTable );
}
$sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
" SELECT $startOpts " . implode( ',', $varMap ) .
" FROM $srcTable $useIndex ";
if ( $conds != '*' ) {
if ( is_array( $conds ) ) {
$conds = $this->makeList( $conds, LIST_AND );
}
$sql .= " WHERE $conds";
}
$sql .= " $tailOpts";
return $this->query( $sql, $fname );
}
/**
* Construct a LIMIT query with optional offset. This is used for query
* pages. The SQL should be adjusted so that only the first $limit rows
* are returned. If $offset is provided as well, then the first $offset
* rows should be discarded, and the next $limit rows should be returned.
* If the result of the query is not ordered, then the rows to be returned
* are theoretically arbitrary.
*
* $sql is expected to be a SELECT, if that makes a difference.
*
* The version provided by default works in MySQL and SQLite. It will very
* likely need to be overridden for most other DBMSes.
*
* @param string $sql SQL query we will append the limit too
* @param int $limit The SQL limit
* @param int|bool $offset The SQL offset (default false)
* @throws DBUnexpectedError
* @return string
*/
public function limitResult( $sql, $limit, $offset = false ) {
if ( !is_numeric( $limit ) ) {
throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
}
return "$sql LIMIT "
. ( ( is_numeric( $offset ) && $offset != 0 ) ? "{$offset}," : "" )
. "{$limit} ";
}
public function unionSupportsOrderAndLimit() {
return true; // True for almost every DB supported
}
public function unionQueries( $sqls, $all ) {
$glue = $all ? ') UNION ALL (' : ') UNION (';
return '(' . implode( $glue, $sqls ) . ')';
}
public function conditional( $cond, $trueVal, $falseVal ) {
if ( is_array( $cond ) ) {
$cond = $this->makeList( $cond, LIST_AND );
}
return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
}
public function strreplace( $orig, $old, $new ) {
return "REPLACE({$orig}, {$old}, {$new})";
}
public function getServerUptime() {
return 0;
}
public function wasDeadlock() {
return false;
}
public function wasLockTimeout() {
return false;
}
public function wasErrorReissuable() {
return false;
}
public function wasReadOnlyError() {
return false;
}
/**
* Determines if the given query error was a connection drop
* STUB
*
* @param integer|string $errno
* @return bool
*/
public function wasConnectionError( $errno ) {
return false;
}
/**
* Perform a deadlock-prone transaction.
*
* This function invokes a callback function to perform a set of write
* queries. If a deadlock occurs during the processing, the transaction
* will be rolled back and the callback function will be called again.
*
* Avoid using this method outside of Job or Maintenance classes.
*
* Usage:
* $dbw->deadlockLoop( callback, ... );
*
* Extra arguments are passed through to the specified callback function.
* This method requires that no transactions are already active to avoid
* causing premature commits or exceptions.
*
* Returns whatever the callback function returned on its successful,
* iteration, or false on error, for example if the retry limit was
* reached.
*
* @return mixed
* @throws DBUnexpectedError
* @throws Exception
*/
public function deadlockLoop() {
$args = func_get_args();
$function = array_shift( $args );
$tries = self::DEADLOCK_TRIES;
$this->begin( __METHOD__ );
$retVal = null;
/** @var Exception $e */
$e = null;
do {
try {
$retVal = call_user_func_array( $function, $args );
break;
} catch ( DBQueryError $e ) {
if ( $this->wasDeadlock() ) {
// Retry after a randomized delay
usleep( mt_rand( self::DEADLOCK_DELAY_MIN, self::DEADLOCK_DELAY_MAX ) );
} else {
// Throw the error back up
throw $e;
}
}
} while ( --$tries > 0 );
if ( $tries <= 0 ) {
// Too many deadlocks; give up
$this->rollback( __METHOD__ );
throw $e;
} else {
$this->commit( __METHOD__ );
return $retVal;
}
}
public function masterPosWait( DBMasterPos $pos, $timeout ) {
# Real waits are implemented in the subclass.
return 0;
}
public function getSlavePos() {
# Stub
return false;
}
public function getMasterPos() {
# Stub
return false;
}
public function serverIsReadOnly() {
return false;
}
final public function onTransactionResolution( callable $callback ) {
if ( !$this->mTrxLevel ) {
throw new DBUnexpectedError( $this, "No transaction is active." );
}
$this->mTrxEndCallbacks[] = [ $callback, wfGetCaller() ];
}
final public function onTransactionIdle( callable $callback ) {
$this->mTrxIdleCallbacks[] = [ $callback, wfGetCaller() ];
if ( !$this->mTrxLevel ) {
$this->runOnTransactionIdleCallbacks( self::TRIGGER_IDLE );
}
}
final public function onTransactionPreCommitOrIdle( callable $callback ) {
if ( $this->mTrxLevel ) {
$this->mTrxPreCommitCallbacks[] = [ $callback, wfGetCaller() ];
} else {
// If no transaction is active, then make one for this callback
$this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
try {
call_user_func( $callback );
$this->commit( __METHOD__ );
} catch ( Exception $e ) {
$this->rollback( __METHOD__ );
throw $e;
}
}
}
final public function setTransactionListener( $name, callable $callback = null ) {
if ( $callback ) {
$this->mTrxRecurringCallbacks[$name] = [ $callback, wfGetCaller() ];
} else {
unset( $this->mTrxRecurringCallbacks[$name] );
}
}
/**
* Whether to disable running of post-COMMIT/ROLLBACK callbacks
*
* This method should not be used outside of Database/LoadBalancer
*
* @param bool $suppress
* @since 1.28
*/
final public function setTrxEndCallbackSuppression( $suppress ) {
$this->mTrxEndCallbacksSuppressed = $suppress;
}
/**
* Actually run and consume any "on transaction idle/resolution" callbacks.
*
* This method should not be used outside of Database/LoadBalancer
*
* @param integer $trigger IDatabase::TRIGGER_* constant
* @since 1.20
* @throws Exception
*/
public function runOnTransactionIdleCallbacks( $trigger ) {
if ( $this->mTrxEndCallbacksSuppressed ) {
return;
}
$autoTrx = $this->getFlag( DBO_TRX ); // automatic begin() enabled?
/** @var Exception $e */
$e = null; // first exception
do { // callbacks may add callbacks :)
$callbacks = array_merge(
$this->mTrxIdleCallbacks,
$this->mTrxEndCallbacks // include "transaction resolution" callbacks
);
$this->mTrxIdleCallbacks = []; // consumed (and recursion guard)
$this->mTrxEndCallbacks = []; // consumed (recursion guard)
foreach ( $callbacks as $callback ) {
try {
list( $phpCallback ) = $callback;
$this->clearFlag( DBO_TRX ); // make each query its own transaction
call_user_func_array( $phpCallback, [ $trigger ] );
if ( $autoTrx ) {
$this->setFlag( DBO_TRX ); // restore automatic begin()
} else {
$this->clearFlag( DBO_TRX ); // restore auto-commit
}
} catch ( Exception $ex ) {
MWExceptionHandler::logException( $ex );
$e = $e ?: $ex;
// Some callbacks may use startAtomic/endAtomic, so make sure
// their transactions are ended so other callbacks don't fail
if ( $this->trxLevel() ) {
$this->rollback( __METHOD__ );
}
}
}
} while ( count( $this->mTrxIdleCallbacks ) );
if ( $e instanceof Exception ) {
throw $e; // re-throw any first exception
}
}
/**
* Actually run and consume any "on transaction pre-commit" callbacks.
*
* This method should not be used outside of Database/LoadBalancer
*
* @since 1.22
* @throws Exception
*/
public function runOnTransactionPreCommitCallbacks() {
$e = null; // first exception
do { // callbacks may add callbacks :)
$callbacks = $this->mTrxPreCommitCallbacks;
$this->mTrxPreCommitCallbacks = []; // consumed (and recursion guard)
foreach ( $callbacks as $callback ) {
try {
list( $phpCallback ) = $callback;
call_user_func( $phpCallback );
} catch ( Exception $ex ) {
MWExceptionHandler::logException( $ex );
$e = $e ?: $ex;
}
}
} while ( count( $this->mTrxPreCommitCallbacks ) );
if ( $e instanceof Exception ) {
throw $e; // re-throw any first exception
}
}
/**
* Actually run any "transaction listener" callbacks.
*
* This method should not be used outside of Database/LoadBalancer
*
* @param integer $trigger IDatabase::TRIGGER_* constant
* @throws Exception
* @since 1.20
*/
public function runTransactionListenerCallbacks( $trigger ) {
if ( $this->mTrxEndCallbacksSuppressed ) {
return;
}
/** @var Exception $e */
$e = null; // first exception
foreach ( $this->mTrxRecurringCallbacks as $callback ) {
try {
list( $phpCallback ) = $callback;
$phpCallback( $trigger, $this );
} catch ( Exception $ex ) {
MWExceptionHandler::logException( $ex );
$e = $e ?: $ex;
}
}
if ( $e instanceof Exception ) {
throw $e; // re-throw any first exception
}
}
final public function startAtomic( $fname = __METHOD__ ) {
if ( !$this->mTrxLevel ) {
$this->begin( $fname, self::TRANSACTION_INTERNAL );
$this->mTrxAutomatic = true;
// If DBO_TRX is set, a series of startAtomic/endAtomic pairs will result
// in all changes being in one transaction to keep requests transactional.
if ( !$this->getFlag( DBO_TRX ) ) {
$this->mTrxAutomaticAtomic = true;
}
}
$this->mTrxAtomicLevels[] = $fname;
}
final public function endAtomic( $fname = __METHOD__ ) {
if ( !$this->mTrxLevel ) {
throw new DBUnexpectedError( $this, "No atomic transaction is open (got $fname)." );
}
if ( !$this->mTrxAtomicLevels ||
array_pop( $this->mTrxAtomicLevels ) !== $fname
) {
throw new DBUnexpectedError( $this, "Invalid atomic section ended (got $fname)." );
}
if ( !$this->mTrxAtomicLevels && $this->mTrxAutomaticAtomic ) {
$this->commit( $fname, self::FLUSHING_INTERNAL );
}
}
final public function doAtomicSection( $fname, callable $callback ) {
$this->startAtomic( $fname );
try {
$res = call_user_func_array( $callback, [ $this, $fname ] );
} catch ( Exception $e ) {
$this->rollback( $fname );
throw $e;
}
$this->endAtomic( $fname );
return $res;
}
final public function begin( $fname = __METHOD__, $mode = self::TRANSACTION_EXPLICIT ) {
// Protect against mismatched atomic section, transaction nesting, and snapshot loss
if ( $this->mTrxLevel ) {
if ( $this->mTrxAtomicLevels ) {
$levels = implode( ', ', $this->mTrxAtomicLevels );
$msg = "$fname: Got explicit BEGIN while atomic section(s) $levels are open.";
throw new DBUnexpectedError( $this, $msg );
} elseif ( !$this->mTrxAutomatic ) {
$msg = "$fname: Explicit transaction already active (from {$this->mTrxFname}).";
throw new DBUnexpectedError( $this, $msg );
} else {
// @TODO: make this an exception at some point
$msg = "$fname: Implicit transaction already active (from {$this->mTrxFname}).";
wfLogDBError( $msg );
return; // join the main transaction set
}
} elseif ( $this->getFlag( DBO_TRX ) && $mode !== self::TRANSACTION_INTERNAL ) {
// @TODO: make this an exception at some point
wfLogDBError( "$fname: Implicit transaction expected (DBO_TRX set)." );
return; // let any writes be in the main transaction
}
// Avoid fatals if close() was called
$this->assertOpen();
$this->doBegin( $fname );
$this->mTrxTimestamp = microtime( true );
$this->mTrxFname = $fname;
$this->mTrxDoneWrites = false;
$this->mTrxAutomatic = false;
$this->mTrxAutomaticAtomic = false;
$this->mTrxAtomicLevels = [];
$this->mTrxShortId = wfRandomString( 12 );
$this->mTrxWriteDuration = 0.0;
$this->mTrxWriteQueryCount = 0;
$this->mTrxWriteAdjDuration = 0.0;
$this->mTrxWriteAdjQueryCount = 0;
$this->mTrxWriteCallers = [];
// First SELECT after BEGIN will establish the snapshot in REPEATABLE-READ.
// Get an estimate of the slave lag before then, treating estimate staleness
// as lag itself just to be safe
$status = $this->getApproximateLagStatus();
$this->mTrxSlaveLag = $status['lag'] + ( microtime( true ) - $status['since'] );
}
/**
* Issues the BEGIN command to the database server.
*
* @see DatabaseBase::begin()
* @param string $fname
*/
protected function doBegin( $fname ) {
$this->query( 'BEGIN', $fname );
$this->mTrxLevel = 1;
}
final public function commit( $fname = __METHOD__, $flush = '' ) {
if ( $this->mTrxLevel && $this->mTrxAtomicLevels ) {
// There are still atomic sections open. This cannot be ignored
$levels = implode( ', ', $this->mTrxAtomicLevels );
throw new DBUnexpectedError(
$this,
"$fname: Got COMMIT while atomic sections $levels are still open."
);
}
if ( $flush === self::FLUSHING_INTERNAL || $flush === self::FLUSHING_ALL_PEERS ) {
if ( !$this->mTrxLevel ) {
return; // nothing to do
} elseif ( !$this->mTrxAutomatic ) {
throw new DBUnexpectedError(
$this,
"$fname: Flushing an explicit transaction, getting out of sync."
);
}
} else {
if ( !$this->mTrxLevel ) {
wfWarn( "$fname: No transaction to commit, something got out of sync." );
return; // nothing to do
} elseif ( $this->mTrxAutomatic ) {
// @TODO: make this an exception at some point
wfLogDBError( "$fname: Explicit commit of implicit transaction." );
return; // wait for the main transaction set commit round
}
}
// Avoid fatals if close() was called
$this->assertOpen();
$this->runOnTransactionPreCommitCallbacks();
$writeTime = $this->pendingWriteQueryDuration();
$this->doCommit( $fname );
if ( $this->mTrxDoneWrites ) {
$this->mDoneWrites = microtime( true );
$this->getTransactionProfiler()->transactionWritingOut(
$this->mServer, $this->mDBname, $this->mTrxShortId, $writeTime );
}
$this->runOnTransactionIdleCallbacks( self::TRIGGER_COMMIT );
$this->runTransactionListenerCallbacks( self::TRIGGER_COMMIT );
}
/**
* Issues the COMMIT command to the database server.
*
* @see DatabaseBase::commit()
* @param string $fname
*/
protected function doCommit( $fname ) {
if ( $this->mTrxLevel ) {
$this->query( 'COMMIT', $fname );
$this->mTrxLevel = 0;
}
}
final public function rollback( $fname = __METHOD__, $flush = '' ) {
if ( $flush === self::FLUSHING_INTERNAL || $flush === self::FLUSHING_ALL_PEERS ) {
if ( !$this->mTrxLevel ) {
return; // nothing to do
}
} else {
if ( !$this->mTrxLevel ) {
wfWarn( "$fname: No transaction to rollback, something got out of sync." );
return; // nothing to do
} elseif ( $this->getFlag( DBO_TRX ) ) {
throw new DBUnexpectedError(
$this,
"$fname: Expected mass rollback of all peer databases (DBO_TRX set)."
);
}
}
// Avoid fatals if close() was called
$this->assertOpen();
$this->doRollback( $fname );
$this->mTrxAtomicLevels = [];
if ( $this->mTrxDoneWrites ) {
$this->getTransactionProfiler()->transactionWritingOut(
$this->mServer, $this->mDBname, $this->mTrxShortId );
}
$this->mTrxIdleCallbacks = []; // clear
$this->mTrxPreCommitCallbacks = []; // clear
$this->runOnTransactionIdleCallbacks( self::TRIGGER_ROLLBACK );
$this->runTransactionListenerCallbacks( self::TRIGGER_ROLLBACK );
}
/**
* Issues the ROLLBACK command to the database server.
*
* @see DatabaseBase::rollback()
* @param string $fname
*/
protected function doRollback( $fname ) {
if ( $this->mTrxLevel ) {
# Disconnects cause rollback anyway, so ignore those errors
$ignoreErrors = true;
$this->query( 'ROLLBACK', $fname, $ignoreErrors );
$this->mTrxLevel = 0;
}
}
public function clearSnapshot( $fname = __METHOD__ ) {
if ( $this->writesOrCallbacksPending() || $this->explicitTrxActive() ) {
// This only flushes transactions to clear snapshots, not to write data
throw new DBUnexpectedError(
$this,
"$fname: Cannot COMMIT to clear snapshot because writes are pending."
);
}
$this->commit( $fname, self::FLUSHING_INTERNAL );
}
public function explicitTrxActive() {
return $this->mTrxLevel && ( $this->mTrxAtomicLevels || !$this->mTrxAutomatic );
}
/**
* Creates a new table with structure copied from existing table
* Note that unlike most database abstraction functions, this function does not
* automatically append database prefix, because it works at a lower
* abstraction level.
* The table names passed to this function shall not be quoted (this
* function calls addIdentifierQuotes when needed).
*
* @param string $oldName Name of table whose structure should be copied
* @param string $newName Name of table to be created
* @param bool $temporary Whether the new table should be temporary
* @param string $fname Calling function name
* @throws MWException
* @return bool True if operation was successful
*/
public function duplicateTableStructure( $oldName, $newName, $temporary = false,
$fname = __METHOD__
) {
throw new MWException(
'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
}
function listTables( $prefix = null, $fname = __METHOD__ ) {
throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
}
/**
* Reset the views process cache set by listViews()
* @since 1.22
*/
final public function clearViewsCache() {
$this->allViews = null;
}
/**
* Lists all the VIEWs in the database
*
* For caching purposes the list of all views should be stored in
* $this->allViews. The process cache can be cleared with clearViewsCache()
*
* @param string $prefix Only show VIEWs with this prefix, eg. unit_test_
* @param string $fname Name of calling function
* @throws MWException
* @return array
* @since 1.22
*/
public function listViews( $prefix = null, $fname = __METHOD__ ) {
throw new MWException( 'DatabaseBase::listViews is not implemented in descendant class' );
}
/**
* Differentiates between a TABLE and a VIEW
*
* @param string $name Name of the database-structure to test.
* @throws MWException
* @return bool
* @since 1.22
*/
public function isView( $name ) {
throw new MWException( 'DatabaseBase::isView is not implemented in descendant class' );
}
public function timestamp( $ts = 0 ) {
return wfTimestamp( TS_MW, $ts );
}
public function timestampOrNull( $ts = null ) {
if ( is_null( $ts ) ) {
return null;
} else {
return $this->timestamp( $ts );
}
}
/**
* Take the result from a query, and wrap it in a ResultWrapper if
* necessary. Boolean values are passed through as is, to indicate success
* of write queries or failure.
*
* Once upon a time, DatabaseBase::query() returned a bare MySQL result
* resource, and it was necessary to call this function to convert it to
* a wrapper. Nowadays, raw database objects are never exposed to external
* callers, so this is unnecessary in external code.
*
* @param bool|ResultWrapper|resource|object $result
* @return bool|ResultWrapper
*/
protected function resultObject( $result ) {
if ( !$result ) {
return false;
} elseif ( $result instanceof ResultWrapper ) {
return $result;
} elseif ( $result === true ) {
// Successful write query
return $result;
} else {
return new ResultWrapper( $this, $result );
}
}
public function ping( &$rtt = null ) {
// Avoid hitting the server if it was hit recently
if ( $this->isOpen() && ( microtime( true ) - $this->lastPing ) < self::PING_TTL ) {
if ( !func_num_args() || $this->mRTTEstimate > 0 ) {
$rtt = $this->mRTTEstimate;
return true; // don't care about $rtt
}
}
// This will reconnect if possible or return false if not
$this->clearFlag( DBO_TRX, self::REMEMBER_PRIOR );
$ok = ( $this->query( self::PING_QUERY, __METHOD__, true ) !== false );
$this->restoreFlags( self::RESTORE_PRIOR );
if ( $ok ) {
$rtt = $this->mRTTEstimate;
}
return $ok;
}
/**
* @return bool
*/
protected function reconnect() {
$this->closeConnection();
$this->mOpened = false;
$this->mConn = false;
try {
$this->open( $this->mServer, $this->mUser, $this->mPassword, $this->mDBname );
$this->lastPing = microtime( true );
$ok = true;
} catch ( DBConnectionError $e ) {
$ok = false;
}
return $ok;
}
public function getSessionLagStatus() {
return $this->getTransactionLagStatus() ?: $this->getApproximateLagStatus();
}
/**
* Get the slave lag when the current transaction started
*
* This is useful when transactions might use snapshot isolation
* (e.g. REPEATABLE-READ in innodb), so the "real" lag of that data
* is this lag plus transaction duration. If they don't, it is still
* safe to be pessimistic. This returns null if there is no transaction.
*
* @return array|null ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)
* @since 1.27
*/
public function getTransactionLagStatus() {
return $this->mTrxLevel
? [ 'lag' => $this->mTrxSlaveLag, 'since' => $this->trxTimestamp() ]
: null;
}
/**
* Get a slave lag estimate for this server
*
* @return array ('lag': seconds or false on error, 'since': UNIX timestamp of estimate)
* @since 1.27
*/
public function getApproximateLagStatus() {
return [
'lag' => $this->getLBInfo( 'slave' ) ? $this->getLag() : 0,
'since' => microtime( true )
];
}
/**
* Merge the result of getSessionLagStatus() for several DBs
* using the most pessimistic values to estimate the lag of
* any data derived from them in combination
*
* This is information is useful for caching modules
*
* @see WANObjectCache::set()
* @see WANObjectCache::getWithSetCallback()
*
* @param IDatabase $db1
* @param IDatabase ...
* @return array Map of values:
* - lag: highest lag of any of the DBs or false on error (e.g. replication stopped)
* - since: oldest UNIX timestamp of any of the DB lag estimates
* - pending: whether any of the DBs have uncommitted changes
* @since 1.27
*/
public static function getCacheSetOptions( IDatabase $db1 ) {
$res = [ 'lag' => 0, 'since' => INF, 'pending' => false ];
foreach ( func_get_args() as $db ) {
/** @var IDatabase $db */
$status = $db->getSessionLagStatus();
if ( $status['lag'] === false ) {
$res['lag'] = false;
} elseif ( $res['lag'] !== false ) {
$res['lag'] = max( $res['lag'], $status['lag'] );
}
$res['since'] = min( $res['since'], $status['since'] );
$res['pending'] = $res['pending'] ?: $db->writesPending();
}
return $res;
}
public function getLag() {
return 0;
}
function maxListLen() {
return 0;
}
public function encodeBlob( $b ) {
return $b;
}
public function decodeBlob( $b ) {
if ( $b instanceof Blob ) {
$b = $b->fetch();
}
return $b;
}
public function setSessionOptions( array $options ) {
}
/**
* Read and execute SQL commands from a file.
*
* Returns true on success, error string or exception on failure (depending
* on object's error ignore settings).
*
* @param string $filename File name to open
* @param bool|callable $lineCallback Optional function called before reading each line
* @param bool|callable $resultCallback Optional function called for each MySQL result
* @param bool|string $fname Calling function name or false if name should be
* generated dynamically using $filename
* @param bool|callable $inputCallback Optional function called for each
* complete line sent
* @throws Exception|MWException
* @return bool|string
*/
public function sourceFile(
$filename, $lineCallback = false, $resultCallback = false, $fname = false, $inputCallback = false
) {
MediaWiki\suppressWarnings();
$fp = fopen( $filename, 'r' );
MediaWiki\restoreWarnings();
if ( false === $fp ) {
throw new MWException( "Could not open \"{$filename}\".\n" );
}
if ( !$fname ) {
$fname = __METHOD__ . "( $filename )";
}
try {
$error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
} catch ( Exception $e ) {
fclose( $fp );
throw $e;
}
fclose( $fp );
return $error;
}
/**
* Get the full path of a patch file. Originally based on archive()
* from updaters.inc. Keep in mind this always returns a patch, as
* it fails back to MySQL if no DB-specific patch can be found
*
* @param string $patch The name of the patch, like patch-something.sql
* @return string Full path to patch file
*/
public function patchPath( $patch ) {
global $IP;
$dbType = $this->getType();
if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
return "$IP/maintenance/$dbType/archives/$patch";
} else {
return "$IP/maintenance/archives/$patch";
}
}
public function setSchemaVars( $vars ) {
$this->mSchemaVars = $vars;
}
/**
* Read and execute commands from an open file handle.
*
* Returns true on success, error string or exception on failure (depending
* on object's error ignore settings).
*
* @param resource $fp File handle
* @param bool|callable $lineCallback Optional function called before reading each query
* @param bool|callable $resultCallback Optional function called for each MySQL result
* @param string $fname Calling function name
* @param bool|callable $inputCallback Optional function called for each complete query sent
* @return bool|string
*/
public function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
$fname = __METHOD__, $inputCallback = false
) {
$cmd = '';
while ( !feof( $fp ) ) {
if ( $lineCallback ) {
call_user_func( $lineCallback );
}
$line = trim( fgets( $fp ) );
if ( $line == '' ) {
continue;
}
if ( '-' == $line[0] && '-' == $line[1] ) {
continue;
}
if ( $cmd != '' ) {
$cmd .= ' ';
}
$done = $this->streamStatementEnd( $cmd, $line );
$cmd .= "$line\n";
if ( $done || feof( $fp ) ) {
$cmd = $this->replaceVars( $cmd );
if ( ( $inputCallback && call_user_func( $inputCallback, $cmd ) ) || !$inputCallback ) {
$res = $this->query( $cmd, $fname );
if ( $resultCallback ) {
call_user_func( $resultCallback, $res, $this );
}
if ( false === $res ) {
$err = $this->lastError();
return "Query \"{$cmd}\" failed with error code \"$err\".\n";
}
}
$cmd = '';
}
}
return true;
}
/**
* Called by sourceStream() to check if we've reached a statement end
*
* @param string $sql SQL assembled so far
* @param string $newLine New line about to be added to $sql
* @return bool Whether $newLine contains end of the statement
*/
public function streamStatementEnd( &$sql, &$newLine ) {
if ( $this->delimiter ) {
$prev = $newLine;
$newLine = preg_replace( '/' . preg_quote( $this->delimiter, '/' ) . '$/', '', $newLine );
if ( $newLine != $prev ) {
return true;
}
}
return false;
}
/**
* Database independent variable replacement. Replaces a set of variables
* in an SQL statement with their contents as given by $this->getSchemaVars().
*
* Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
*
* - '{$var}' should be used for text and is passed through the database's
* addQuotes method.
* - `{$var}` should be used for identifiers (e.g. table and database names).
* It is passed through the database's addIdentifierQuotes method which
* can be overridden if the database uses something other than backticks.
* - / *_* / or / *$wgDBprefix* / passes the name that follows through the
* database's tableName method.
* - / *i* / passes the name that follows through the database's indexName method.
* - In all other cases, / *$var* / is left unencoded. Except for table options,
* its use should be avoided. In 1.24 and older, string encoding was applied.
*
* @param string $ins SQL statement to replace variables in
* @return string The new SQL statement with variables replaced
*/
protected function replaceVars( $ins ) {
$vars = $this->getSchemaVars();
return preg_replace_callback(
'!
/\* (\$wgDBprefix|[_i]) \*/ (\w*) | # 1-2. tableName, indexName
\'\{\$ (\w+) }\' | # 3. addQuotes
`\{\$ (\w+) }` | # 4. addIdentifierQuotes
/\*\$ (\w+) \*/ # 5. leave unencoded
!x',
function ( $m ) use ( $vars ) {
// Note: Because of <https://bugs.php.net/bug.php?id=51881>,
// check for both nonexistent keys *and* the empty string.
if ( isset( $m[1] ) && $m[1] !== '' ) {
if ( $m[1] === 'i' ) {
return $this->indexName( $m[2] );
} else {
return $this->tableName( $m[2] );
}
} elseif ( isset( $m[3] ) && $m[3] !== '' && array_key_exists( $m[3], $vars ) ) {
return $this->addQuotes( $vars[$m[3]] );
} elseif ( isset( $m[4] ) && $m[4] !== '' && array_key_exists( $m[4], $vars ) ) {
return $this->addIdentifierQuotes( $vars[$m[4]] );
} elseif ( isset( $m[5] ) && $m[5] !== '' && array_key_exists( $m[5], $vars ) ) {
return $vars[$m[5]];
} else {
return $m[0];
}
},
$ins
);
}
/**
* Get schema variables. If none have been set via setSchemaVars(), then
* use some defaults from the current object.
*
* @return array
*/
protected function getSchemaVars() {
if ( $this->mSchemaVars ) {
return $this->mSchemaVars;
} else {
return $this->getDefaultSchemaVars();
}
}
/**
* Get schema variables to use if none have been set via setSchemaVars().
*
* Override this in derived classes to provide variables for tables.sql
* and SQL patch files.
*
* @return array
*/
protected function getDefaultSchemaVars() {
return [];
}
public function lockIsFree( $lockName, $method ) {
return true;
}
public function lock( $lockName, $method, $timeout = 5 ) {
$this->mNamedLocksHeld[$lockName] = 1;
return true;
}
public function unlock( $lockName, $method ) {
unset( $this->mNamedLocksHeld[$lockName] );
return true;
}
public function getScopedLockAndFlush( $lockKey, $fname, $timeout ) {
if ( $this->writesOrCallbacksPending() ) {
// This only flushes transactions to clear snapshots, not to write data
throw new DBUnexpectedError(
$this,
"$fname: Cannot COMMIT to clear snapshot because writes are pending."
);
}
if ( !$this->lock( $lockKey, $fname, $timeout ) ) {
return null;
}
$unlocker = new ScopedCallback( function () use ( $lockKey, $fname ) {
if ( $this->trxLevel() ) {
// There is a good chance an exception was thrown, causing any early return
// from the caller. Let any error handler get a chance to issue rollback().
// If there isn't one, let the error bubble up and trigger server-side rollback.
$this->onTransactionResolution( function () use ( $lockKey, $fname ) {
$this->unlock( $lockKey, $fname );
} );
} else {
$this->unlock( $lockKey, $fname );
}
} );
$this->commit( __METHOD__, self::FLUSHING_INTERNAL );
return $unlocker;
}
public function namedLocksEnqueue() {
return false;
}
/**
* Lock specific tables
*
* @param array $read Array of tables to lock for read access
* @param array $write Array of tables to lock for write access
* @param string $method Name of caller
* @param bool $lowPriority Whether to indicate writes to be LOW PRIORITY
* @return bool
*/
public function lockTables( $read, $write, $method, $lowPriority = true ) {
return true;
}
/**
* Unlock specific tables
*
* @param string $method The caller
* @return bool
*/
public function unlockTables( $method ) {
return true;
}
/**
* Delete a table
* @param string $tableName
* @param string $fName
* @return bool|ResultWrapper
* @since 1.18
*/
public function dropTable( $tableName, $fName = __METHOD__ ) {
if ( !$this->tableExists( $tableName, $fName ) ) {
return false;
}
$sql = "DROP TABLE " . $this->tableName( $tableName );
if ( $this->cascadingDeletes() ) {
$sql .= " CASCADE";
}
return $this->query( $sql, $fName );
}
/**
* Get search engine class. All subclasses of this need to implement this
* if they wish to use searching.
*
* @return string
*/
public function getSearchEngine() {
return 'SearchEngineDummy';
}
public function getInfinity() {
return 'infinity';
}
public function encodeExpiry( $expiry ) {
return ( $expiry == '' || $expiry == 'infinity' || $expiry == $this->getInfinity() )
? $this->getInfinity()
: $this->timestamp( $expiry );
}
public function decodeExpiry( $expiry, $format = TS_MW ) {
return ( $expiry == '' || $expiry == 'infinity' || $expiry == $this->getInfinity() )
? 'infinity'
: wfTimestamp( $format, $expiry );
}
public function setBigSelects( $value = true ) {
// no-op
}
public function isReadOnly() {
return ( $this->getReadOnlyReason() !== false );
}
/**
* @return string|bool Reason this DB is read-only or false if it is not
*/
protected function getReadOnlyReason() {
$reason = $this->getLBInfo( 'readOnlyReason' );
return is_string( $reason ) ? $reason : false;
}
/**
* @since 1.19
* @return string
*/
public function __toString() {
return (string)$this->mConn;
}
/**
* Run a few simple sanity checks
*/
public function __destruct() {
if ( $this->mTrxLevel && $this->mTrxDoneWrites ) {
trigger_error( "Uncommitted DB writes (transaction from {$this->mTrxFname})." );
}
$danglingCallbacks = array_merge(
$this->mTrxIdleCallbacks,
$this->mTrxPreCommitCallbacks,
$this->mTrxEndCallbacks
);
if ( $danglingCallbacks ) {
$callers = [];
foreach ( $danglingCallbacks as $callbackInfo ) {
$callers[] = $callbackInfo[1];
}
$callers = implode( ', ', $callers );
trigger_error( "DB transaction callbacks still pending (from $callers)." );
}
}
}
/**
* @since 1.27
*/
abstract class Database extends DatabaseBase {
// B/C until nothing type hints for DatabaseBase
// @TODO: finish renaming DatabaseBase => Database
}
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