Current File : /www/varak.net/wiki.varak.net/includes/libs/rdbms/database/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
*/
namespace Wikimedia\Rdbms;
use Psr\Log\LoggerAwareInterface;
use Psr\Log\LoggerInterface;
use Psr\Log\NullLogger;
use Wikimedia\ScopedCallback;
use Wikimedia\Timestamp\ConvertibleTimestamp;
use Wikimedia;
use BagOStuff;
use HashBagOStuff;
use LogicException;
use InvalidArgumentException;
use UnexpectedValueException;
use Exception;
use RuntimeException;
/**
* Relational database abstraction object
*
* @ingroup Database
* @since 1.28
*/
abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAwareInterface {
/** 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 = 0.010;
const SLOW_WRITE_SEC = 0.500;
const SMALL_WRITE_ROWS = 100;
/** @var string Whether lock granularity is on the level of the entire database */
const ATTR_DB_LEVEL_LOCKING = 'db-level-locking';
/** @var int New Database instance will not be connected yet when returned */
const NEW_UNCONNECTED = 0;
/** @var int New Database instance will already be connected when returned */
const NEW_CONNECTED = 1;
/** @var string SQL query */
protected $lastQuery = '';
/** @var float|bool UNIX timestamp of last write query */
protected $lastWriteTime = false;
/** @var string|bool */
protected $phpError = false;
/** @var string Server that this instance is currently connected to */
protected $server;
/** @var string User that this instance is currently connected under the name of */
protected $user;
/** @var string Password used to establish the current connection */
protected $password;
/** @var array[] Map of (table => (dbname, schema, prefix) map) */
protected $tableAliases = [];
/** @var string[] Map of (index alias => index) */
protected $indexAliases = [];
/** @var bool Whether this PHP instance is for a CLI script */
protected $cliMode;
/** @var string Agent name for query profiling */
protected $agent;
/** @var array Parameters used by initConnection() to establish a connection */
protected $connectionParams = [];
/** @var BagOStuff APC cache */
protected $srvCache;
/** @var LoggerInterface */
protected $connLogger;
/** @var LoggerInterface */
protected $queryLogger;
/** @var callback Error logging callback */
protected $errorLogger;
/** @var callback Deprecation logging callback */
protected $deprecationLogger;
/** @var resource|null Database connection */
protected $conn = null;
/** @var bool */
protected $opened = false;
/** @var array[] List of (callable, method name, atomic section id) */
protected $trxIdleCallbacks = [];
/** @var array[] List of (callable, method name, atomic section id) */
protected $trxPreCommitCallbacks = [];
/** @var array[] List of (callable, method name, atomic section id) */
protected $trxEndCallbacks = [];
/** @var callable[] Map of (name => callable) */
protected $trxRecurringCallbacks = [];
/** @var bool Whether to suppress triggering of transaction end callbacks */
protected $trxEndCallbacksSuppressed = false;
/** @var int */
protected $flags;
/** @var array */
protected $lbInfo = [];
/** @var array|bool */
protected $schemaVars = false;
/** @var array */
protected $sessionVars = [];
/** @var array|null */
protected $preparedArgs;
/** @var string|bool|null Stashed value of html_errors INI setting */
protected $htmlErrors;
/** @var string */
protected $delimiter = ';';
/** @var DatabaseDomain */
protected $currentDomain;
/** @var integer|null Rows affected by the last query to query() or its CRUD wrappers */
protected $affectedRowCount;
/**
* @var int Transaction status
*/
protected $trxStatus = self::STATUS_TRX_NONE;
/**
* @var Exception|null The last error that caused the status to become STATUS_TRX_ERROR
*/
protected $trxStatusCause;
/**
* @var array|null If wasKnownStatementRollbackError() prevented trxStatus from being set,
* the relevant details are stored here.
*/
protected $trxStatusIgnoredCause;
/**
* 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 $trxLevel = 0;
/**
* Either a short hexidecimal string if a transaction is active or ""
*
* @var string
* @see Database::trxLevel
*/
protected $trxShortId = '';
/**
* 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 Database::trxLevel
*/
private $trxTimestamp = null;
/** @var float Lag estimate at the time of BEGIN */
private $trxReplicaLag = 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 Database::trxLevel
*/
private $trxFname = null;
/**
* Record if possible write queries were done in the last transaction started
*
* @var bool
* @see Database::trxLevel
*/
private $trxDoneWrites = false;
/**
* Record if the current transaction was started implicitly due to DBO_TRX being set.
*
* @var bool
* @see Database::trxLevel
*/
private $trxAutomatic = false;
/**
* Counter for atomic savepoint identifiers. Reset when a new transaction begins.
*
* @var int
*/
private $trxAtomicCounter = 0;
/**
* Array of levels of atomicity within transactions
*
* @var array List of (name, unique ID, savepoint ID)
*/
private $trxAtomicLevels = [];
/**
* Record if the current transaction was started implicitly by Database::startAtomic
*
* @var bool
*/
private $trxAutomaticAtomic = false;
/**
* Track the write query callers of the current transaction
*
* @var string[]
*/
private $trxWriteCallers = [];
/**
* @var float Seconds spent in write queries for the current transaction
*/
private $trxWriteDuration = 0.0;
/**
* @var int Number of write queries for the current transaction
*/
private $trxWriteQueryCount = 0;
/**
* @var int Number of rows affected by write queries for the current transaction
*/
private $trxWriteAffectedRows = 0;
/**
* @var float Like trxWriteQueryCount but excludes lock-bound, easy to replicate, queries
*/
private $trxWriteAdjDuration = 0.0;
/**
* @var int Number of write queries counted in trxWriteAdjDuration
*/
private $trxWriteAdjQueryCount = 0;
/**
* @var float RTT time estimate
*/
private $rttEstimate = 0.0;
/** @var array Map of (name => 1) for locks obtained via lock() */
private $namedLocksHeld = [];
/** @var array Map of (table name => 1) for TEMPORARY tables */
protected $sessionTempTables = [];
/** @var IDatabase|null Lazy handle to the master DB this server replicates from */
private $lazyMasterHandle;
/** @var float UNIX timestamp */
protected $lastPing = 0.0;
/** @var int[] Prior flags member variable values */
private $priorFlags = [];
/** @var mixed Class name or object With profileIn/profileOut methods */
protected $profiler;
/** @var TransactionProfiler */
protected $trxProfiler;
/** @var int */
protected $nonNativeInsertSelectBatchSize = 10000;
/** @var string Idiom used when a cancelable atomic section started the transaction */
private static $NOT_APPLICABLE = 'n/a';
/** @var string Prefix to the atomic section counter used to make savepoint IDs */
private static $SAVEPOINT_PREFIX = 'wikimedia_rdbms_atomic';
/** @var int Transaction is in a error state requiring a full or savepoint rollback */
const STATUS_TRX_ERROR = 1;
/** @var int Transaction is active and in a normal state */
const STATUS_TRX_OK = 2;
/** @var int No transaction is active */
const STATUS_TRX_NONE = 3;
/**
* @note exceptions for missing libraries/drivers should be thrown in initConnection()
* @param array $params Parameters passed from Database::factory()
*/
protected function __construct( array $params ) {
foreach ( [ 'host', 'user', 'password', 'dbname', 'schema', 'tablePrefix' ] as $name ) {
$this->connectionParams[$name] = $params[$name];
}
$this->cliMode = $params['cliMode'];
// Agent name is added to SQL queries in a comment, so make sure it can't break out
$this->agent = str_replace( '/', '-', $params['agent'] );
$this->flags = $params['flags'];
if ( $this->flags & self::DBO_DEFAULT ) {
if ( $this->cliMode ) {
$this->flags &= ~self::DBO_TRX;
} else {
$this->flags |= self::DBO_TRX;
}
}
// Disregard deprecated DBO_IGNORE flag (T189999)
$this->flags &= ~self::DBO_IGNORE;
$this->sessionVars = $params['variables'];
$this->srvCache = $params['srvCache'] ?? new HashBagOStuff();
$this->profiler = $params['profiler'];
$this->trxProfiler = $params['trxProfiler'];
$this->connLogger = $params['connLogger'];
$this->queryLogger = $params['queryLogger'];
$this->errorLogger = $params['errorLogger'];
$this->deprecationLogger = $params['deprecationLogger'];
if ( isset( $params['nonNativeInsertSelectBatchSize'] ) ) {
$this->nonNativeInsertSelectBatchSize = $params['nonNativeInsertSelectBatchSize'];
}
// Set initial dummy domain until open() sets the final DB/prefix
$this->currentDomain = new DatabaseDomain(
$params['dbname'] != '' ? $params['dbname'] : null,
$params['schema'] != '' ? $params['schema'] : null,
$params['tablePrefix']
);
}
/**
* Initialize the connection to the database over the wire (or to local files)
*
* @throws LogicException
* @throws InvalidArgumentException
* @throws DBConnectionError
* @since 1.31
*/
final public function initConnection() {
if ( $this->isOpen() ) {
throw new LogicException( __METHOD__ . ': already connected.' );
}
// Establish the connection
$this->doInitConnection();
}
/**
* Actually connect to the database over the wire (or to local files)
*
* @throws InvalidArgumentException
* @throws DBConnectionError
* @since 1.31
*/
protected function doInitConnection() {
if ( strlen( $this->connectionParams['user'] ) ) {
$this->open(
$this->connectionParams['host'],
$this->connectionParams['user'],
$this->connectionParams['password'],
$this->connectionParams['dbname'],
$this->connectionParams['schema'],
$this->connectionParams['tablePrefix']
);
} else {
throw new InvalidArgumentException( "No database user provided." );
}
}
/**
* Open a new connection to the database (closing any existing one)
*
* @param string $server Database server host
* @param string $user Database user name
* @param string $password Database user password
* @param string $dbName Database name
* @param string|null $schema Database schema name
* @param string $tablePrefix Table prefix
* @return bool
* @throws DBConnectionError
*/
abstract protected function open( $server, $user, $password, $dbName, $schema, $tablePrefix );
/**
* Construct a Database subclass instance given a database type and parameters
*
* This also connects to the database immediately upon object construction
*
* @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
* @param array $p Parameter map with keys:
* - host : The hostname of the DB server
* - user : The name of the database user the client operates under
* - password : The password for the database user
* - dbname : The name of the database to use where queries do not specify one.
* The database must exist or an error might be thrown. Setting this to the empty string
* will avoid any such errors and make the handle have no implicit database scope. This is
* useful for queries like SHOW STATUS, CREATE DATABASE, or DROP DATABASE. Note that a
* "database" in Postgres is rougly equivalent to an entire MySQL server. This the domain
* in which user names and such are defined, e.g. users are database-specific in Postgres.
* - schema : The database schema to use (if supported). A "schema" in Postgres is roughly
* equivalent to a "database" in MySQL. Note that MySQL and SQLite do not use schemas.
* - tablePrefix : Optional table prefix that is implicitly added on to all table names
* recognized in queries. This can be used in place of schemas for handle site farms.
* - flags : Optional bitfield of DBO_* constants that define connection, protocol,
* buffering, and transaction behavior. It is STRONGLY adviced to leave the DBO_DEFAULT
* flag in place UNLESS this this database simply acts as a key/value store.
* - driver: Optional name of a specific DB client driver. For MySQL, there is only the
* 'mysqli' driver; the old one 'mysql' has been removed.
* - variables: Optional map of session variables to set after connecting. This can be
* used to adjust lock timeouts or encoding modes and the like.
* - connLogger: Optional PSR-3 logger interface instance.
* - queryLogger: Optional PSR-3 logger interface instance.
* - profiler: Optional class name or object with profileIn()/profileOut() methods.
* These will be called in query(), using a simplified version of the SQL that also
* includes the agent as a SQL comment.
* - trxProfiler: Optional TransactionProfiler instance.
* - errorLogger: Optional callback that takes an Exception and logs it.
* - deprecationLogger: Optional callback that takes a string and logs it.
* - cliMode: Whether to consider the execution context that of a CLI script.
* - agent: Optional name used to identify the end-user in query profiling/logging.
* - srvCache: Optional BagOStuff instance to an APC-style cache.
* - nonNativeInsertSelectBatchSize: Optional batch size for non-native INSERT SELECT emulation.
* @param int $connect One of the class constants (NEW_CONNECTED, NEW_UNCONNECTED) [optional]
* @return Database|null If the database driver or extension cannot be found
* @throws InvalidArgumentException If the database driver or extension cannot be found
* @since 1.18
*/
final public static function factory( $dbType, $p = [], $connect = self::NEW_CONNECTED ) {
$class = self::getClass( $dbType, $p['driver'] ?? null );
if ( class_exists( $class ) && is_subclass_of( $class, IDatabase::class ) ) {
// Resolve some defaults for b/c
$p['host'] = $p['host'] ?? false;
$p['user'] = $p['user'] ?? false;
$p['password'] = $p['password'] ?? false;
$p['dbname'] = $p['dbname'] ?? false;
$p['flags'] = $p['flags'] ?? 0;
$p['variables'] = $p['variables'] ?? [];
$p['tablePrefix'] = $p['tablePrefix'] ?? '';
$p['schema'] = $p['schema'] ?? null;
$p['cliMode'] = $p['cliMode'] ?? ( PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg' );
$p['agent'] = $p['agent'] ?? '';
if ( !isset( $p['connLogger'] ) ) {
$p['connLogger'] = new NullLogger();
}
if ( !isset( $p['queryLogger'] ) ) {
$p['queryLogger'] = new NullLogger();
}
$p['profiler'] = $p['profiler'] ?? null;
if ( !isset( $p['trxProfiler'] ) ) {
$p['trxProfiler'] = new TransactionProfiler();
}
if ( !isset( $p['errorLogger'] ) ) {
$p['errorLogger'] = function ( Exception $e ) {
trigger_error( get_class( $e ) . ': ' . $e->getMessage(), E_USER_WARNING );
};
}
if ( !isset( $p['deprecationLogger'] ) ) {
$p['deprecationLogger'] = function ( $msg ) {
trigger_error( $msg, E_USER_DEPRECATED );
};
}
/** @var Database $conn */
$conn = new $class( $p );
if ( $connect == self::NEW_CONNECTED ) {
$conn->initConnection();
}
} else {
$conn = null;
}
return $conn;
}
/**
* @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
* @param string|null $driver Optional name of a specific DB client driver
* @return array Map of (Database::ATTRIBUTE_* constant => value) for all such constants
* @throws InvalidArgumentException
* @since 1.31
*/
final public static function attributesFromType( $dbType, $driver = null ) {
static $defaults = [ self::ATTR_DB_LEVEL_LOCKING => false ];
$class = self::getClass( $dbType, $driver );
return call_user_func( [ $class, 'getAttributes' ] ) + $defaults;
}
/**
* @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
* @param string|null $driver Optional name of a specific DB client driver
* @return string Database subclass name to use
* @throws InvalidArgumentException
*/
private static function getClass( $dbType, $driver = null ) {
// For database types with built-in support, the below maps type to IDatabase
// implementations. For types with multipe driver implementations (PHP extensions),
// an array can be used, keyed by extension name. In case of an array, the
// optional 'driver' parameter can be used to force a specific driver. Otherwise,
// we auto-detect the first available driver. For types without built-in support,
// an class named "Database<Type>" us used, eg. DatabaseFoo for type 'foo'.
static $builtinTypes = [
'mssql' => DatabaseMssql::class,
'mysql' => [ 'mysqli' => DatabaseMysqli::class ],
'sqlite' => DatabaseSqlite::class,
'postgres' => DatabasePostgres::class,
];
$dbType = strtolower( $dbType );
$class = false;
if ( isset( $builtinTypes[$dbType] ) ) {
$possibleDrivers = $builtinTypes[$dbType];
if ( is_string( $possibleDrivers ) ) {
$class = $possibleDrivers;
} else {
if ( (string)$driver !== '' ) {
if ( !isset( $possibleDrivers[$driver] ) ) {
throw new InvalidArgumentException( __METHOD__ .
" type '$dbType' does not support driver '{$driver}'" );
} else {
$class = $possibleDrivers[$driver];
}
} else {
foreach ( $possibleDrivers as $posDriver => $possibleClass ) {
if ( extension_loaded( $posDriver ) ) {
$class = $possibleClass;
break;
}
}
}
}
} else {
$class = 'Database' . ucfirst( $dbType );
}
if ( $class === false ) {
throw new InvalidArgumentException( __METHOD__ .
" no viable database extension found for type '$dbType'" );
}
return $class;
}
/**
* @return array Map of (Database::ATTRIBUTE_* constant => value
* @since 1.31
*/
protected static function getAttributes() {
return [];
}
/**
* Set the PSR-3 logger interface to use for query logging. (The logger
* interfaces for connection logging and error logging can be set with the
* constructor.)
*
* @param LoggerInterface $logger
*/
public function setLogger( LoggerInterface $logger ) {
$this->queryLogger = $logger;
}
public function getServerInfo() {
return $this->getServerVersion();
}
public function bufferResults( $buffer = null ) {
$res = !$this->getFlag( self::DBO_NOBUFFER );
if ( $buffer !== null ) {
$buffer
? $this->clearFlag( self::DBO_NOBUFFER )
: $this->setFlag( self::DBO_NOBUFFER );
}
return $res;
}
public function trxLevel() {
return $this->trxLevel;
}
public function trxTimestamp() {
return $this->trxLevel ? $this->trxTimestamp : null;
}
/**
* @return int One of the STATUS_TRX_* class constants
* @since 1.31
*/
public function trxStatus() {
return $this->trxStatus;
}
public function tablePrefix( $prefix = null ) {
$old = $this->currentDomain->getTablePrefix();
if ( $prefix !== null ) {
$this->currentDomain = new DatabaseDomain(
$this->currentDomain->getDatabase(),
$this->currentDomain->getSchema(),
$prefix
);
}
return $old;
}
public function dbSchema( $schema = null ) {
$old = $this->currentDomain->getSchema();
if ( $schema !== null ) {
$this->currentDomain = new DatabaseDomain(
$this->currentDomain->getDatabase(),
// DatabaseDomain uses null for unspecified schemas
strlen( $schema ) ? $schema : null,
$this->currentDomain->getTablePrefix()
);
}
return (string)$old;
}
/**
* @return string Schema to use to qualify relations in queries
*/
protected function relationSchemaQualifier() {
return $this->dbSchema();
}
public function getLBInfo( $name = null ) {
if ( is_null( $name ) ) {
return $this->lbInfo;
} else {
if ( array_key_exists( $name, $this->lbInfo ) ) {
return $this->lbInfo[$name];
} else {
return null;
}
}
}
public function setLBInfo( $name, $value = null ) {
if ( is_null( $value ) ) {
$this->lbInfo = $name;
} else {
$this->lbInfo[$name] = $value;
}
}
public function setLazyMasterHandle( IDatabase $conn ) {
$this->lazyMasterHandle = $conn;
}
/**
* @return IDatabase|null
* @see setLazyMasterHandle()
* @since 1.27
*/
protected function getLazyMasterHandle() {
return $this->lazyMasterHandle;
}
public function implicitGroupby() {
return true;
}
public function implicitOrderby() {
return true;
}
public function lastQuery() {
return $this->lastQuery;
}
public function doneWrites() {
return (bool)$this->lastWriteTime;
}
public function lastDoneWrites() {
return $this->lastWriteTime ?: false;
}
public function writesPending() {
return $this->trxLevel && $this->trxDoneWrites;
}
public function writesOrCallbacksPending() {
return $this->trxLevel && (
$this->trxDoneWrites ||
$this->trxIdleCallbacks ||
$this->trxPreCommitCallbacks ||
$this->trxEndCallbacks
);
}
public function preCommitCallbacksPending() {
return $this->trxLevel && $this->trxPreCommitCallbacks;
}
/**
* @return string|null
*/
final protected function getTransactionRoundId() {
// If transaction round participation is enabled, see if one is active
if ( $this->getFlag( self::DBO_TRX ) ) {
$id = $this->getLBInfo( 'trxRoundId' );
return is_string( $id ) ? $id : null;
}
return null;
}
public function pendingWriteQueryDuration( $type = self::ESTIMATE_TOTAL ) {
if ( !$this->trxLevel ) {
return false;
} elseif ( !$this->trxDoneWrites ) {
return 0.0;
}
switch ( $type ) {
case self::ESTIMATE_DB_APPLY:
$this->ping( $rtt );
$rttAdjTotal = $this->trxWriteAdjQueryCount * $rtt;
$applyTime = max( $this->trxWriteAdjDuration - $rttAdjTotal, 0 );
// For omitted queries, make them count as something at least
$omitted = $this->trxWriteQueryCount - $this->trxWriteAdjQueryCount;
$applyTime += self::TINY_WRITE_SEC * $omitted;
return $applyTime;
default: // everything
return $this->trxWriteDuration;
}
}
public function pendingWriteCallers() {
return $this->trxLevel ? $this->trxWriteCallers : [];
}
public function pendingWriteRowsAffected() {
return $this->trxWriteAffectedRows;
}
/**
* List the methods that have write queries or callbacks for the current transaction
*
* This method should not be used outside of Database/LoadBalancer
*
* @return string[]
* @since 1.32
*/
public function pendingWriteAndCallbackCallers() {
$fnames = $this->pendingWriteCallers();
foreach ( [
$this->trxIdleCallbacks,
$this->trxPreCommitCallbacks,
$this->trxEndCallbacks
] as $callbacks ) {
foreach ( $callbacks as $callback ) {
$fnames[] = $callback[1];
}
}
return $fnames;
}
/**
* @return string
*/
private function flatAtomicSectionList() {
return array_reduce( $this->trxAtomicLevels, function ( $accum, $v ) {
return $accum === null ? $v[0] : "$accum, " . $v[0];
} );
}
public function isOpen() {
return $this->opened;
}
public function setFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
if ( ( $flag & self::DBO_IGNORE ) ) {
throw new UnexpectedValueException( "Modifying DBO_IGNORE is not allowed." );
}
if ( $remember === self::REMEMBER_PRIOR ) {
array_push( $this->priorFlags, $this->flags );
}
$this->flags |= $flag;
}
public function clearFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
if ( ( $flag & self::DBO_IGNORE ) ) {
throw new UnexpectedValueException( "Modifying DBO_IGNORE is not allowed." );
}
if ( $remember === self::REMEMBER_PRIOR ) {
array_push( $this->priorFlags, $this->flags );
}
$this->flags &= ~$flag;
}
public function restoreFlags( $state = self::RESTORE_PRIOR ) {
if ( !$this->priorFlags ) {
return;
}
if ( $state === self::RESTORE_INITIAL ) {
$this->flags = reset( $this->priorFlags );
$this->priorFlags = [];
} else {
$this->flags = array_pop( $this->priorFlags );
}
}
public function getFlag( $flag ) {
return !!( $this->flags & $flag );
}
/**
* @param string $name Class field name
* @return mixed
* @deprecated Since 1.28
*/
public function getProperty( $name ) {
return $this->$name;
}
public function getDomainID() {
return $this->currentDomain->getId();
}
final public function getWikiID() {
return $this->getDomainID();
}
/**
* 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 );
/**
* Set a custom error handler for logging errors during database connection
*/
protected function installErrorHandler() {
$this->phpError = false;
$this->htmlErrors = ini_set( 'html_errors', '0' );
set_error_handler( [ $this, 'connectionErrorLogger' ] );
}
/**
* Restore the previous error handler and return the last PHP error for this DB
*
* @return bool|string
*/
protected function restoreErrorHandler() {
restore_error_handler();
if ( $this->htmlErrors !== false ) {
ini_set( 'html_errors', $this->htmlErrors );
}
return $this->getLastPHPError();
}
/**
* @return string|bool Last PHP error for this DB (typically connection errors)
*/
protected function getLastPHPError() {
if ( $this->phpError ) {
$error = preg_replace( '!\[<a.*</a>\]!', '', $this->phpError );
$error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
return $error;
}
return false;
}
/**
* Error handler for logging errors during database connection
* This method should not be used outside of Database classes
*
* @param int $errno
* @param string $errstr
*/
public function connectionErrorLogger( $errno, $errstr ) {
$this->phpError = $errstr;
}
/**
* Create a log context to pass to PSR-3 logger functions.
*
* @param array $extras Additional data to add to context
* @return array
*/
protected function getLogContext( array $extras = [] ) {
return array_merge(
[
'db_server' => $this->server,
'db_name' => $this->getDBname(),
'db_user' => $this->user,
],
$extras
);
}
final public function close() {
$exception = null; // error to throw after disconnecting
if ( $this->conn ) {
// Roll back any dangling transaction first
if ( $this->trxLevel ) {
if ( $this->trxAtomicLevels ) {
// Cannot let incomplete atomic sections be committed
$levels = $this->flatAtomicSectionList();
$exception = new DBUnexpectedError(
$this,
__METHOD__ . ": atomic sections $levels are still open."
);
} elseif ( $this->trxAutomatic ) {
// Only the connection manager can commit non-empty DBO_TRX transactions
// (empty ones we can silently roll back)
if ( $this->writesOrCallbacksPending() ) {
$exception = new DBUnexpectedError(
$this,
__METHOD__ .
": mass commit/rollback of peer transaction required (DBO_TRX set)."
);
}
} else {
// Manual transactions should have been committed or rolled
// back, even if empty.
$exception = new DBUnexpectedError(
$this,
__METHOD__ . ": transaction is still open (from {$this->trxFname})."
);
}
if ( $this->trxEndCallbacksSuppressed ) {
$exception = $exception ?: new DBUnexpectedError(
$this,
__METHOD__ . ': callbacks are suppressed; cannot properly commit.'
);
}
// Rollback the changes and run any callbacks as needed
$this->rollback( __METHOD__, self::FLUSHING_INTERNAL );
}
// Close the actual connection in the binding handle
$closed = $this->closeConnection();
$this->conn = false;
} else {
$closed = true; // already closed; nothing to do
}
$this->opened = false;
// Throw any unexpected errors after having disconnected
if ( $exception instanceof Exception ) {
throw $exception;
}
// Sanity check that no callbacks are dangling
$fnames = $this->pendingWriteAndCallbackCallers();
if ( $fnames ) {
throw new RuntimeException(
"Transaction callbacks are still pending:\n" . implode( ', ', $fnames )
);
}
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();
/**
* @deprecated since 1.32
* @param string $error Fallback message, if none is given by DB
* @throws DBConnectionError
*/
public function reportConnectionError( $error = 'Unknown error' ) {
call_user_func( $this->deprecationLogger, 'Use of ' . __METHOD__ . ' is deprecated.' );
throw new DBConnectionError( $this, $this->lastError() ?: $error );
}
/**
* Run a query and return a DBMS-dependent wrapper (that has all IResultWrapper methods)
*
* This might return things, such as mysqli_result, that do not formally implement
* IResultWrapper, but nonetheless implement all of its methods correctly
*
* @param string $sql SQL query.
* @return IResultWrapper|bool Iterator to feed to fetchObject/fetchRow; false on failure
*/
abstract protected function doQuery( $sql );
/**
* Determine whether a query writes to the DB. When in doubt, this returns true.
*
* Main use cases:
*
* - Subsequent web requests should not need to wait for replication from
* the master position seen by this web request, unless this request made
* changes to the master. This is handled by ChronologyProtector by checking
* doneWrites() at the end of the request. doneWrites() returns true if any
* query set lastWriteTime; which query() does based on isWriteQuery().
*
* - Reject write queries to replica DBs, in query().
*
* @param string $sql
* @return bool
*/
protected function isWriteQuery( $sql ) {
// BEGIN and COMMIT queries are considered read queries here.
// Database backends and drivers (MySQL, MariaDB, php-mysqli) generally
// treat these as write queries, in that their results have "affected rows"
// as meta data as from writes, instead of "num rows" as from reads.
// But, we treat them as read queries because when reading data (from
// either replica or master) we use transactions to enable repeatable-read
// snapshots, which ensures we get consistent results from the same snapshot
// for all queries within a request. Use cases:
// - Treating these as writes would trigger ChronologyProtector (see method doc).
// - We use this method to reject writes to replicas, but we need to allow
// use of transactions on replicas for read snapshots. This fine given
// that transactions by themselves don't make changes, only actual writes
// within the transaction matter, which we still detect.
return !preg_match(
'/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
}
/**
* @param string $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.
*
* Main purpose: Used by query() to decide whether to begin a transaction
* before the current query (in DBO_TRX mode, on by default).
*
* @param string $sql
* @return bool
*/
protected function isTransactableQuery( $sql ) {
return !in_array(
$this->getQueryVerb( $sql ),
[ 'BEGIN', 'ROLLBACK', 'COMMIT', 'SET', 'SHOW', 'CREATE', 'ALTER' ],
true
);
}
/**
* @param string $sql A SQL query
* @return bool Whether $sql is SQL for TEMPORARY table operation
*/
protected function registerTempTableOperation( $sql ) {
if ( preg_match(
'/^CREATE\s+TEMPORARY\s+TABLE\s+(?:IF\s+NOT\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
$sql,
$matches
) ) {
$this->sessionTempTables[$matches[1]] = 1;
return true;
} elseif ( preg_match(
'/^DROP\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
$sql,
$matches
) ) {
$isTemp = isset( $this->sessionTempTables[$matches[1]] );
unset( $this->sessionTempTables[$matches[1]] );
return $isTemp;
} elseif ( preg_match(
'/^TRUNCATE\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
$sql,
$matches
) ) {
return isset( $this->sessionTempTables[$matches[1]] );
} elseif ( preg_match(
'/^(?:INSERT\s+(?:\w+\s+)?INTO|UPDATE|DELETE\s+FROM)\s+[`"\']?(\w+)[`"\']?/i',
$sql,
$matches
) ) {
return isset( $this->sessionTempTables[$matches[1]] );
}
return false;
}
public function query( $sql, $fname = __METHOD__, $tempIgnore = false ) {
$this->assertTransactionStatus( $sql, $fname );
# Avoid fatals if close() was called
$this->assertOpen();
$priorWritesPending = $this->writesOrCallbacksPending();
$this->lastQuery = $sql;
$isWrite = $this->isWriteQuery( $sql );
if ( $isWrite ) {
$isNonTempWrite = !$this->registerTempTableOperation( $sql );
} else {
$isNonTempWrite = false;
}
if ( $isWrite ) {
if ( $this->getLBInfo( 'replica' ) === true ) {
throw new DBError(
$this,
'Write operations are not allowed on replica database connections.'
);
}
# In theory, non-persistent writes are allowed in read-only mode, but due to things
# like https://bugs.mysql.com/bug.php?id=33669 that might not work anyway...
$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->lastWriteTime = microtime( true );
}
# 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 (T44598)
$commentedSql = preg_replace( '/\s|$/', " /* $fname {$this->agent} */ ", $sql, 1 );
# Start implicit transactions that wrap the request if DBO_TRX is enabled
if ( !$this->trxLevel && $this->getFlag( self::DBO_TRX )
&& $this->isTransactableQuery( $sql )
) {
$this->begin( __METHOD__ . " ($fname)", self::TRANSACTION_INTERNAL );
$this->trxAutomatic = true;
}
# Keep track of whether the transaction has write queries pending
if ( $this->trxLevel && !$this->trxDoneWrites && $isWrite ) {
$this->trxDoneWrites = true;
$this->trxProfiler->transactionWritingIn(
$this->server, $this->getDomainID(), $this->trxShortId );
}
if ( $this->getFlag( self::DBO_DEBUG ) ) {
$this->queryLogger->debug( "{$this->getDomainID()} {$commentedSql}" );
}
# Send the query to the server and fetch any corresponding errors
$ret = $this->doProfiledQuery( $sql, $commentedSql, $isNonTempWrite, $fname );
$lastError = $this->lastError();
$lastErrno = $this->lastErrno();
# Try reconnecting if the connection was lost
if ( $ret === false && $this->wasConnectionLoss() ) {
# Check if any meaningful session state was lost
$recoverable = $this->canRecoverFromDisconnect( $sql, $priorWritesPending );
# Update session state tracking and try to restore the connection
$reconnected = $this->replaceLostConnection( __METHOD__ );
# Silently resend the query to the server if it is safe and possible
if ( $reconnected && $recoverable ) {
$ret = $this->doProfiledQuery( $sql, $commentedSql, $isNonTempWrite, $fname );
$lastError = $this->lastError();
$lastErrno = $this->lastErrno();
if ( $ret === false && $this->wasConnectionLoss() ) {
# Query probably causes disconnects; reconnect and do not re-run it
$this->replaceLostConnection( __METHOD__ );
}
}
}
if ( $ret === false ) {
if ( $this->trxLevel ) {
if ( $this->wasKnownStatementRollbackError() ) {
# We're ignoring an error that caused just the current query to be aborted.
# But log the cause so we can log a deprecation notice if a caller actually
# does ignore it.
$this->trxStatusIgnoredCause = [ $lastError, $lastErrno, $fname ];
} else {
# Either the query was aborted or all queries after BEGIN where aborted.
# In the first case, the only options going forward are (a) ROLLBACK, or
# (b) ROLLBACK TO SAVEPOINT (if one was set). If the later case, the only
# option is ROLLBACK, since the snapshots would have been released.
$this->trxStatus = self::STATUS_TRX_ERROR;
$this->trxStatusCause =
$this->makeQueryException( $lastError, $lastErrno, $sql, $fname );
$tempIgnore = false; // cannot recover
$this->trxStatusIgnoredCause = null;
}
}
$this->reportQueryError( $lastError, $lastErrno, $sql, $fname, $tempIgnore );
}
return $this->resultObject( $ret );
}
/**
* Wrapper for query() that also handles profiling, logging, and affected row count updates
*
* @param string $sql Original SQL query
* @param string $commentedSql SQL query with debugging/trace comment
* @param bool $isWrite Whether the query is a (non-temporary) write operation
* @param string $fname Name of the calling function
* @return bool|ResultWrapper True for a successful write query, ResultWrapper
* object for a successful read query, or false on failure
*/
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( self::generalizeSQL( $sql ), 0, 255 );
} else {
$queryProf = 'query: ' . substr( self::generalizeSQL( $sql ), 0, 255 );
}
# Include query transaction state
$queryProf .= $this->trxShortId ? " [TRX#{$this->trxShortId}]" : "";
$startTime = microtime( true );
if ( $this->profiler ) {
$this->profiler->profileIn( $queryProf );
}
$this->affectedRowCount = null;
$ret = $this->doQuery( $commentedSql );
$this->affectedRowCount = $this->affectedRows();
if ( $this->profiler ) {
$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->trxLevel ) {
$this->updateTrxWriteQueryTime( $sql, $queryRuntime, $this->affectedRows() );
$this->trxWriteCallers[] = $fname;
}
}
if ( $sql === self::PING_QUERY ) {
$this->rttEstimate = $queryRuntime;
}
$this->trxProfiler->recordQueryCompletion(
$queryProf,
$startTime,
$isWrite,
$isWrite ? $this->affectedRows() : $this->numRows( $ret )
);
$this->queryLogger->debug( $sql, [
'method' => $fname,
'master' => $isMaster,
'runtime' => $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 A SQL write query
* @param float $runtime Total runtime, including RTT
* @param int $affected Affected row count
*/
private function updateTrxWriteQueryTime( $sql, $runtime, $affected ) {
// Whether this is indicative of replica DB runtime (except for RBR or ws_repl)
$indicativeOfReplicaRuntime = 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' ) {
$indicativeOfReplicaRuntime = $this->affectedRows() > self::SMALL_WRITE_ROWS;
} elseif ( $verb === 'REPLACE' ) {
$indicativeOfReplicaRuntime = $this->affectedRows() > self::SMALL_WRITE_ROWS / 2;
}
}
$this->trxWriteDuration += $runtime;
$this->trxWriteQueryCount += 1;
$this->trxWriteAffectedRows += $affected;
if ( $indicativeOfReplicaRuntime ) {
$this->trxWriteAdjDuration += $runtime;
$this->trxWriteAdjQueryCount += 1;
}
}
/**
* @param string $sql
* @param string $fname
* @throws DBTransactionStateError
*/
private function assertTransactionStatus( $sql, $fname ) {
if ( $this->getQueryVerb( $sql ) === 'ROLLBACK' ) { // transaction/savepoint
return;
}
if ( $this->trxStatus < self::STATUS_TRX_OK ) {
throw new DBTransactionStateError(
$this,
"Cannot execute query from $fname while transaction status is ERROR.",
[],
$this->trxStatusCause
);
} elseif ( $this->trxStatus === self::STATUS_TRX_OK && $this->trxStatusIgnoredCause ) {
list( $iLastError, $iLastErrno, $iFname ) = $this->trxStatusIgnoredCause;
call_user_func( $this->deprecationLogger,
"Caller from $fname ignored an error originally raised from $iFname: " .
"[$iLastErrno] $iLastError"
);
$this->trxStatusIgnoredCause = null;
}
}
public function assertNoOpenTransactions() {
if ( $this->explicitTrxActive() ) {
throw new DBTransactionError(
$this,
"Explicit transaction still active. A caller may have caught an error. "
. "Open transactions: " . $this->flatAtomicSectionList()
);
}
}
/**
* Determine whether or not it is safe to retry queries after a database
* connection is lost
*
* @param string $sql SQL query
* @param bool $priorWritesPending Whether there is a transaction open with
* possible write queries or transaction pre-commit/idle callbacks
* waiting on it to finish.
* @return bool True if it is safe to retry the query, false otherwise
*/
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->namedLocksHeld ) {
return false; // possible critical section violation
} elseif ( $this->sessionTempTables ) {
return false; // tables might be queried latter
} 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 and explicit snapshots
} elseif ( $priorWritesPending ) {
return false; // prior writes lost from implicit transaction
}
return true;
}
/**
* Clean things up after session (and thus transaction) loss
*/
private function handleSessionLoss() {
// Clean up tracking of session-level things...
// https://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html
// https://www.postgresql.org/docs/9.2/static/sql-createtable.html (ignoring ON COMMIT)
$this->sessionTempTables = [];
// https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
// https://www.postgresql.org/docs/9.4/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
$this->namedLocksHeld = [];
// Session loss implies transaction loss
$this->handleTransactionLoss();
}
/**
* Clean things up after transaction loss
*/
private function handleTransactionLoss() {
$this->trxLevel = 0;
$this->trxAtomicCounter = 0;
$this->trxIdleCallbacks = []; // T67263; transaction already lost
$this->trxPreCommitCallbacks = []; // T67263; transaction already lost
try {
// Handle callbacks in trxEndCallbacks, e.g. onTransactionResolution().
// If callback suppression is set then the array will remain unhandled.
$this->runOnTransactionIdleCallbacks( self::TRIGGER_ROLLBACK );
} catch ( Exception $ex ) {
// Already logged; move on...
}
try {
// Handle callbacks in trxRecurringCallbacks, e.g. setTransactionListener()
$this->runTransactionListenerCallbacks( self::TRIGGER_ROLLBACK );
} catch ( Exception $ex ) {
// Already logged; move on...
}
}
/**
* Checks whether the cause of the error is detected to be a timeout.
*
* It returns false by default, and not all engines support detecting this yet.
* If this returns false, it will be treated as a generic query error.
*
* @param string $error Error text
* @param int $errno Error number
* @return bool
*/
protected function wasQueryTimeout( $error, $errno ) {
return false;
}
/**
* Report a query error. Log the error, and if neither the object ignore
* flag nor the $tempIgnore flag is set, throw a DBQueryError.
*
* @param string $error
* @param int $errno
* @param string $sql
* @param string $fname
* @param bool $tempIgnore
* @throws DBQueryError
*/
public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
if ( $tempIgnore ) {
$this->queryLogger->debug( "SQL ERROR (ignored): $error\n" );
} else {
$exception = $this->makeQueryException( $error, $errno, $sql, $fname );
throw $exception;
}
}
/**
* @param string $error
* @param string|int $errno
* @param string $sql
* @param string $fname
* @return DBError
*/
private function makeQueryException( $error, $errno, $sql, $fname ) {
$sql1line = mb_substr( str_replace( "\n", "\\n", $sql ), 0, 5 * 1024 );
$this->queryLogger->error(
"{fname}\t{db_server}\t{errno}\t{error}\t{sql1line}",
$this->getLogContext( [
'method' => __METHOD__,
'errno' => $errno,
'error' => $error,
'sql1line' => $sql1line,
'fname' => $fname,
] )
);
$this->queryLogger->debug( "SQL ERROR: " . $error . "\n" );
$wasQueryTimeout = $this->wasQueryTimeout( $error, $errno );
if ( $wasQueryTimeout ) {
$e = new DBQueryTimeoutError( $this, $error, $errno, $sql, $fname );
} else {
$e = new DBQueryError( $this, $error, $errno, $sql, $fname );
}
return $e;
}
public function freeResult( $res ) {
}
public function selectField(
$table, $var, $cond = '', $fname = __METHOD__, $options = [], $join_conds = []
) {
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, $join_conds );
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, [ 'value' => $var ], $cond, $fname, $options, $join_conds );
if ( $res === false ) {
return false;
}
$values = [];
foreach ( $res as $row ) {
$values[] = $row->value;
}
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 Database::select()
*/
protected 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( $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 = '';
}
if ( isset( $options['IGNORE INDEX'] ) && is_string( $options['IGNORE INDEX'] ) ) {
$ignoreIndex = $this->ignoreIndexClause( $options['IGNORE INDEX'] );
} else {
$ignoreIndex = '';
}
return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ];
}
/**
* Returns an optional GROUP BY with an optional HAVING
*
* @param array $options Associative array of options
* @return string
* @see Database::select()
* @since 1.21
*/
protected 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'], self::LIST_AND )
: $options['HAVING'];
$sql .= ' HAVING ' . $having;
}
return $sql;
}
/**
* Returns an optional ORDER BY
*
* @param array $options Associative array of options
* @return string
* @see Database::select()
* @since 1.21
*/
protected 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 '';
}
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 ) ) {
$fields = implode( ',', $this->fieldNamesWithAlias( $vars ) );
} else {
$fields = $vars;
}
$options = (array)$options;
$useIndexes = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
? $options['USE INDEX']
: [];
$ignoreIndexes = (
isset( $options['IGNORE INDEX'] ) &&
is_array( $options['IGNORE INDEX'] )
)
? $options['IGNORE INDEX']
: [];
if (
$this->selectOptionsIncludeLocking( $options ) &&
$this->selectFieldsOrOptionsAggregate( $vars, $options )
) {
// Some DB types (postgres/oracle) disallow FOR UPDATE with aggregate
// functions. Discourage use of such queries to encourage compatibility.
call_user_func(
$this->deprecationLogger,
__METHOD__ . ": aggregation used with a locking SELECT ($fname)."
);
}
if ( is_array( $table ) ) {
$from = ' FROM ' .
$this->tableNamesWithIndexClauseOrJOIN(
$table, $useIndexes, $ignoreIndexes, $join_conds );
} elseif ( $table != '' ) {
$from = ' FROM ' .
$this->tableNamesWithIndexClauseOrJOIN(
[ $table ], $useIndexes, $ignoreIndexes, [] );
} else {
$from = '';
}
list( $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ) =
$this->makeSelectOptions( $options );
if ( is_array( $conds ) ) {
$conds = $this->makeList( $conds, self::LIST_AND );
}
if ( $conds === null || $conds === false ) {
$this->queryLogger->warning(
__METHOD__
. ' called from '
. $fname
. ' with incorrect parameters: $conds must be a string or an array'
);
$conds = '';
}
if ( $conds === '' || $conds === '*' ) {
$sql = "SELECT $startOpts $fields $from $useIndex $ignoreIndex $preLimitTail";
} elseif ( is_string( $conds ) ) {
$sql = "SELECT $startOpts $fields $from $useIndex $ignoreIndex " .
"WHERE $conds $preLimitTail";
} else {
throw new DBUnexpectedError( $this, __METHOD__ . ' called with incorrect parameters' );
}
if ( isset( $options['LIMIT'] ) ) {
$sql = $this->limitResult( $sql, $options['LIMIT'],
$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, $var = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
) {
$conds = $this->normalizeConditions( $conds, $fname );
$column = $this->extractSingleFieldFromList( $var );
if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
$conds[] = "$column IS NOT NULL";
}
$res = $this->select(
$table, [ 'rowcount' => 'COUNT(*)' ], $conds, $fname, $options, $join_conds
);
$row = $res ? $this->fetchRow( $res ) : [];
return isset( $row['rowcount'] ) ? (int)$row['rowcount'] : 0;
}
public function selectRowCount(
$tables, $var = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
) {
$conds = $this->normalizeConditions( $conds, $fname );
$column = $this->extractSingleFieldFromList( $var );
if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
$conds[] = "$column IS NOT NULL";
}
$res = $this->select(
[
'tmp_count' => $this->buildSelectSubquery(
$tables,
'1',
$conds,
$fname,
$options,
$join_conds
)
],
[ 'rowcount' => 'COUNT(*)' ],
[],
$fname
);
$row = $res ? $this->fetchRow( $res ) : [];
return isset( $row['rowcount'] ) ? (int)$row['rowcount'] : 0;
}
/**
* @param string|array $options
* @return bool
*/
private function selectOptionsIncludeLocking( $options ) {
$options = (array)$options;
foreach ( [ 'FOR UPDATE', 'LOCK IN SHARE MODE' ] as $lock ) {
if ( in_array( $lock, $options, true ) ) {
return true;
}
}
return false;
}
/**
* @param array|string $fields
* @param array|string $options
* @return bool
*/
private function selectFieldsOrOptionsAggregate( $fields, $options ) {
foreach ( (array)$options as $key => $value ) {
if ( is_string( $key ) ) {
if ( preg_match( '/^(?:GROUP BY|HAVING)$/i', $key ) ) {
return true;
}
} elseif ( is_string( $value ) ) {
if ( preg_match( '/^(?:DISTINCT|DISTINCTROW)$/i', $value ) ) {
return true;
}
}
}
$regex = '/^(?:COUNT|MIN|MAX|SUM|GROUP_CONCAT|LISTAGG|ARRAY_AGG)\s*\\(/i';
foreach ( (array)$fields as $field ) {
if ( is_string( $field ) && preg_match( $regex, $field ) ) {
return true;
}
}
return false;
}
/**
* @param array|string $conds
* @param string $fname
* @return array
*/
final protected function normalizeConditions( $conds, $fname ) {
if ( $conds === null || $conds === false ) {
$this->queryLogger->warning(
__METHOD__
. ' called from '
. $fname
. ' with incorrect parameters: $conds must be a string or an array'
);
$conds = '';
}
if ( !is_array( $conds ) ) {
$conds = ( $conds === '' ) ? [] : [ $conds ];
}
return $conds;
}
/**
* @param array|string $var Field parameter in the style of select()
* @return string|null Column name or null; ignores aliases
* @throws DBUnexpectedError Errors out if multiple columns are given
*/
final protected function extractSingleFieldFromList( $var ) {
if ( is_array( $var ) ) {
if ( !$var ) {
$column = null;
} elseif ( count( $var ) == 1 ) {
$column = $var[0] ?? reset( $var );
} else {
throw new DBUnexpectedError( $this, __METHOD__ . ': got multiple columns.' );
}
} else {
$column = $var;
}
return $column;
}
public function lockForUpdate(
$table, $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
) {
if ( !$this->trxLevel && !$this->getFlag( self::DBO_TRX ) ) {
throw new DBUnexpectedError(
$this,
__METHOD__ . ': no transaction is active nor is DBO_TRX set'
);
}
$options = (array)$options;
$options[] = 'FOR UPDATE';
return $this->selectRowCount( $table, '*', $conds, $fname, $options, $join_conds );
}
/**
* 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;
}
}
abstract public function tableExists( $table, $fname = __METHOD__ );
public function indexUnique( $table, $index ) {
$indexInfo = $this->indexInfo( $table, $index );
if ( !$indexInfo ) {
return null;
}
return !$indexInfo[0]->Non_unique;
}
/**
* Helper for Database::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 Database::makeUpdateOptions
*
* @param array $options
* @return array
*/
protected function makeUpdateOptionsArray( $options ) {
if ( !is_array( $options ) ) {
$options = [ $options ];
}
$opts = [];
if ( in_array( 'IGNORE', $options ) ) {
$opts[] = 'IGNORE';
}
return $opts;
}
/**
* Make UPDATE options for the Database::update function
*
* @param array $options The options passed to Database::update
* @return string
*/
protected function makeUpdateOptions( $options ) {
$opts = $this->makeUpdateOptionsArray( $options );
return implode( ' ', $opts );
}
public function update( $table, $values, $conds, $fname = __METHOD__, $options = [] ) {
$table = $this->tableName( $table );
$opts = $this->makeUpdateOptions( $options );
$sql = "UPDATE $opts $table SET " . $this->makeList( $values, self::LIST_SET );
if ( $conds !== [] && $conds !== '*' ) {
$sql .= " WHERE " . $this->makeList( $conds, self::LIST_AND );
}
return (bool)$this->query( $sql, $fname );
}
public function makeList( $a, $mode = self::LIST_COMMA ) {
if ( !is_array( $a ) ) {
throw new DBUnexpectedError( $this, __METHOD__ . ' called with incorrect parameters' );
}
$first = true;
$list = '';
foreach ( $a as $field => $value ) {
if ( !$first ) {
if ( $mode == self::LIST_AND ) {
$list .= ' AND ';
} elseif ( $mode == self::LIST_OR ) {
$list .= ' OR ';
} else {
$list .= ',';
}
} else {
$first = false;
}
if ( ( $mode == self::LIST_AND || $mode == self::LIST_OR ) && is_numeric( $field ) ) {
$list .= "($value)";
} elseif ( $mode == self::LIST_SET && is_numeric( $field ) ) {
$list .= "$value";
} elseif (
( $mode == self::LIST_AND || $mode == self::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 InvalidArgumentException(
__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 == self::LIST_AND || $mode == self::LIST_OR ) {
$list .= "$field IS ";
} elseif ( $mode == self::LIST_SET ) {
$list .= "$field = ";
}
$list .= 'NULL';
} else {
if (
$mode == self::LIST_AND || $mode == self::LIST_OR || $mode == self::LIST_SET
) {
$list .= "$field = ";
}
$list .= $mode == self::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 ) ],
self::LIST_AND );
}
}
if ( $conds ) {
return $this->makeList( $conds, self::LIST_OR );
} else {
// Nothing to search for...
return false;
}
}
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 buildSubstring( $input, $startPosition, $length = null ) {
$this->assertBuildSubstringParams( $startPosition, $length );
$functionBody = "$input FROM $startPosition";
if ( $length !== null ) {
$functionBody .= " FOR $length";
}
return 'SUBSTRING(' . $functionBody . ')';
}
/**
* Check type and bounds for parameters to self::buildSubstring()
*
* All supported databases have substring functions that behave the same for
* positive $startPosition and non-negative $length, but behaviors differ when
* given 0 or negative $startPosition or negative $length. The simplest
* solution to that is to just forbid those values.
*
* @param int $startPosition
* @param int|null $length
* @since 1.31
*/
protected function assertBuildSubstringParams( $startPosition, $length ) {
if ( !is_int( $startPosition ) || $startPosition <= 0 ) {
throw new InvalidArgumentException(
'$startPosition must be a positive integer'
);
}
if ( !( is_int( $length ) && $length >= 0 || $length === null ) ) {
throw new InvalidArgumentException(
'$length must be null or an integer greater than or equal to 0'
);
}
}
public function buildStringCast( $field ) {
return $field;
}
public function buildIntegerCast( $field ) {
return 'CAST( ' . $field . ' AS INTEGER )';
}
public function buildSelectSubquery(
$table, $vars, $conds = '', $fname = __METHOD__,
$options = [], $join_conds = []
) {
return new Subquery(
$this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds )
);
}
public function databasesAreIndependent() {
return false;
}
final public function selectDB( $db ) {
$this->selectDomain( new DatabaseDomain(
$db,
$this->currentDomain->getSchema(),
$this->currentDomain->getTablePrefix()
) );
return true;
}
final public function selectDomain( $domain ) {
$this->doSelectDomain( DatabaseDomain::newFromId( $domain ) );
}
protected function doSelectDomain( DatabaseDomain $domain ) {
$this->currentDomain = $domain;
}
public function getDBname() {
return $this->currentDomain->getDatabase();
}
public function getServer() {
return $this->server;
}
public function tableName( $name, $format = 'quoted' ) {
if ( $name instanceof Subquery ) {
throw new DBUnexpectedError(
$this,
__METHOD__ . ': got Subquery instance when expecting a string.'
);
}
# 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 ) {
$this->queryLogger->warning(
__METHOD__ . ": use of subqueries is not supported this way.",
[ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
);
return $name;
}
# Split database and table into proper variables.
list( $database, $schema, $prefix, $table ) = $this->qualifiedTableComponents( $name );
# 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 $database and merge them with the table name if needed
$tableName = $this->prependDatabaseOrSchema( $schema, $tableName, $format );
$tableName = $this->prependDatabaseOrSchema( $database, $tableName, $format );
return $tableName;
}
/**
* Get the table components needed for a query given the currently selected database
*
* @param string $name Table name in the form of db.schema.table, db.table, or table
* @return array (DB name or "" for default, schema name, table prefix, table name)
*/
protected function qualifiedTableComponents( $name ) {
# 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
$prefix = '';
# In dbs that support it, $database may actually be the schema
# but that doesn't affect any of the functionality here
$schema = '';
} else {
list( $table ) = $dbDetails;
if ( isset( $this->tableAliases[$table] ) ) {
$database = $this->tableAliases[$table]['dbname'];
$schema = is_string( $this->tableAliases[$table]['schema'] )
? $this->tableAliases[$table]['schema']
: $this->relationSchemaQualifier();
$prefix = is_string( $this->tableAliases[$table]['prefix'] )
? $this->tableAliases[$table]['prefix']
: $this->tablePrefix();
} else {
$database = '';
$schema = $this->relationSchemaQualifier(); # Default schema
$prefix = $this->tablePrefix(); # Default prefix
}
}
return [ $database, $schema, $prefix, $table ];
}
/**
* @param string|null $namespace Database or schema
* @param string $relation Name of table, view, sequence, etc...
* @param string $format One of (raw, quoted)
* @return string Relation name with quoted and merged $namespace as needed
*/
private function prependDatabaseOrSchema( $namespace, $relation, $format ) {
if ( strlen( $namespace ) ) {
if ( $format === 'quoted' && !$this->isQuotedIdentifier( $namespace ) ) {
$namespace = $this->addIdentifierQuotes( $namespace );
}
$relation = $namespace . '.' . $relation;
}
return $relation;
}
public function tableNames() {
$inArray = func_get_args();
$retVal = [];
foreach ( $inArray as $name ) {
$retVal[$name] = $this->tableName( $name );
}
return $retVal;
}
public function tableNamesN() {
$inArray = func_get_args();
$retVal = [];
foreach ( $inArray as $name ) {
$retVal[] = $this->tableName( $name );
}
return $retVal;
}
/**
* Get an aliased table name
*
* This returns strings like "tableName AS newTableName" for aliased tables
* and "(SELECT * from tableA) newTablename" for subqueries (e.g. derived tables)
*
* @see Database::tableName()
* @param string|Subquery $table Table name or object with a 'sql' field
* @param string|bool $alias Table alias (optional)
* @return string SQL name for aliased table. Will not alias a table to its own name
*/
protected function tableNameWithAlias( $table, $alias = false ) {
if ( is_string( $table ) ) {
$quotedTable = $this->tableName( $table );
} elseif ( $table instanceof Subquery ) {
$quotedTable = (string)$table;
} else {
throw new InvalidArgumentException( "Table must be a string or Subquery." );
}
if ( !strlen( $alias ) || $alias === $table ) {
if ( $table instanceof Subquery ) {
throw new InvalidArgumentException( "Subquery table missing alias." );
}
return $quotedTable;
} else {
return $quotedTable . ' ' . $this->addIdentifierQuotes( $alias );
}
}
/**
* Gets an array of aliased table names
*
* @param array $tables [ [alias] => table ]
* @return string[] See tableNameWithAlias()
*/
protected 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
*/
protected 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()
*/
protected 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 or IGNORE INDEX clause
*
* @param array $tables ( [alias] => table )
* @param array $use_index Same as for select()
* @param array $ignore_index Same as for select()
* @param array $join_conds Same as for select()
* @return string
*/
protected function tableNamesWithIndexClauseOrJOIN(
$tables, $use_index = [], $ignore_index = [], $join_conds = []
) {
$ret = [];
$retJOIN = [];
$use_index = (array)$use_index;
$ignore_index = (array)$ignore_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;
}
if ( is_array( $table ) ) {
// A parenthesized group
if ( count( $table ) > 1 ) {
$joinedTable = '(' .
$this->tableNamesWithIndexClauseOrJOIN(
$table, $use_index, $ignore_index, $join_conds ) . ')';
} else {
// Degenerate case
$innerTable = reset( $table );
$innerAlias = key( $table );
$joinedTable = $this->tableNameWithAlias(
$innerTable,
is_string( $innerAlias ) ? $innerAlias : $innerTable
);
}
} else {
$joinedTable = $this->tableNameWithAlias( $table, $alias );
}
// Is there a JOIN clause for this table?
if ( isset( $join_conds[$alias] ) ) {
list( $joinType, $conds ) = $join_conds[$alias];
$tableClause = $joinType;
$tableClause .= ' ' . $joinedTable;
if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
$use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
if ( $use != '' ) {
$tableClause .= ' ' . $use;
}
}
if ( isset( $ignore_index[$alias] ) ) { // has IGNORE INDEX?
$ignore = $this->ignoreIndexClause(
implode( ',', (array)$ignore_index[$alias] ) );
if ( $ignore != '' ) {
$tableClause .= ' ' . $ignore;
}
}
$on = $this->makeList( (array)$conds, self::LIST_AND );
if ( $on != '' ) {
$tableClause .= ' ON (' . $on . ')';
}
$retJOIN[] = $tableClause;
} elseif ( isset( $use_index[$alias] ) ) {
// Is there an INDEX clause for this table?
$tableClause = $joinedTable;
$tableClause .= ' ' . $this->useIndexClause(
implode( ',', (array)$use_index[$alias] )
);
$ret[] = $tableClause;
} elseif ( isset( $ignore_index[$alias] ) ) {
// Is there an INDEX clause for this table?
$tableClause = $joinedTable;
$tableClause .= ' ' . $this->ignoreIndexClause(
implode( ',', (array)$ignore_index[$alias] )
);
$ret[] = $tableClause;
} else {
$tableClause = $joinedTable;
$ret[] = $tableClause;
}
}
// We can't separate explicit JOIN clauses with ',', use ' ' for those
$implicitJoins = $ret ? implode( ',', $ret ) : "";
$explicitJoins = $retJOIN ? implode( ' ', $retJOIN ) : "";
// Compile our final table clause
return implode( ' ', [ $implicitJoins, $explicitJoins ] );
}
/**
* Allows for index remapping in queries where this is not consistent across DBMS
*
* @param string $index
* @return string
*/
protected function indexName( $index ) {
return $this->indexAliases[$index] ?? $index;
}
public function addQuotes( $s ) {
if ( $s instanceof Blob ) {
$s = $s->fetch();
}
if ( $s === null ) {
return 'NULL';
} elseif ( is_bool( $s ) ) {
return (int)$s;
} 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 DatabaseMysqlBase.
*
* @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
* @param string $escapeChar
* @return string
*/
protected function escapeLikeInternal( $s, $escapeChar = '`' ) {
return str_replace( [ $escapeChar, '%', '_' ],
[ "{$escapeChar}{$escapeChar}", "{$escapeChar}%", "{$escapeChar}_" ],
$s );
}
public function buildLike() {
$params = func_get_args();
if ( count( $params ) > 0 && is_array( $params[0] ) ) {
$params = $params[0];
}
$s = '';
// We use ` instead of \ as the default LIKE escape character, since addQuotes()
// may escape backslashes, creating problems of double escaping. The `
// character has good cross-DBMS compatibility, avoiding special operators
// in MS SQL like ^ and %
$escapeChar = '`';
foreach ( $params as $value ) {
if ( $value instanceof LikeMatch ) {
$s .= $value->toString();
} else {
$s .= $this->escapeLikeInternal( $value, $escapeChar );
}
}
return ' LIKE ' .
$this->addQuotes( $s ) . ' ESCAPE ' . $this->addQuotes( $escapeChar ) . ' ';
}
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 '';
}
/**
* IGNORE 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 ignoreIndexClause( $index ) {
return '';
}
public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
if ( count( $rows ) == 0 ) {
return;
}
// Single row case
if ( !is_array( reset( $rows ) ) ) {
$rows = [ $rows ];
}
try {
$this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
$affectedRowCount = 0;
foreach ( $rows as $row ) {
// Delete rows which collide with this one
$indexWhereClauses = [];
foreach ( $uniqueIndexes as $index ) {
$indexColumns = (array)$index;
$indexRowValues = array_intersect_key( $row, array_flip( $indexColumns ) );
if ( count( $indexRowValues ) != count( $indexColumns ) ) {
throw new DBUnexpectedError(
$this,
'New record does not provide all values for unique key (' .
implode( ', ', $indexColumns ) . ')'
);
} elseif ( in_array( null, $indexRowValues, true ) ) {
throw new DBUnexpectedError(
$this,
'New record has a null value for unique key (' .
implode( ', ', $indexColumns ) . ')'
);
}
$indexWhereClauses[] = $this->makeList( $indexRowValues, LIST_AND );
}
if ( $indexWhereClauses ) {
$this->delete( $table, $this->makeList( $indexWhereClauses, LIST_OR ), $fname );
$affectedRowCount += $this->affectedRows();
}
// Now insert the row
$this->insert( $table, $row, $fname );
$affectedRowCount += $this->affectedRows();
}
$this->endAtomic( $fname );
$this->affectedRowCount = $affectedRowCount;
} catch ( Exception $e ) {
$this->cancelAtomic( $fname );
throw $e;
}
}
/**
* 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, self::LIST_AND );
}
}
$where = [ $this->makeList( $clauses, self::LIST_OR ) ];
} else {
$where = false;
}
$affectedRowCount = 0;
try {
$this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
# Update any existing conflicting row(s)
if ( $where !== false ) {
$ok = $this->update( $table, $set, $where, $fname );
$affectedRowCount += $this->affectedRows();
} else {
$ok = true;
}
# Now insert any non-conflicting row(s)
$ok = $this->insert( $table, $rows, $fname, [ 'IGNORE' ] ) && $ok;
$affectedRowCount += $this->affectedRows();
$this->endAtomic( $fname );
$this->affectedRowCount = $affectedRowCount;
} catch ( Exception $e ) {
$this->cancelAtomic( $fname );
throw $e;
}
return $ok;
}
public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
$fname = __METHOD__
) {
if ( !$conds ) {
throw new DBUnexpectedError( $this, __METHOD__ . ' 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, self::LIST_AND );
}
$sql .= ')';
$this->query( $sql, $fname );
}
public function textFieldSize( $table, $field ) {
$table = $this->tableName( $table );
$sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
$res = $this->query( $sql, __METHOD__ );
$row = $this->fetchObject( $res );
$m = [];
if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
$size = $m[1];
} else {
$size = -1;
}
return $size;
}
public function delete( $table, $conds, $fname = __METHOD__ ) {
if ( !$conds ) {
throw new DBUnexpectedError( $this, __METHOD__ . ' called with no conditions' );
}
$table = $this->tableName( $table );
$sql = "DELETE FROM $table";
if ( $conds != '*' ) {
if ( is_array( $conds ) ) {
$conds = $this->makeList( $conds, self::LIST_AND );
}
$sql .= ' WHERE ' . $conds;
}
return $this->query( $sql, $fname );
}
final public function insertSelect(
$destTable, $srcTable, $varMap, $conds,
$fname = __METHOD__, $insertOptions = [], $selectOptions = [], $selectJoinConds = []
) {
static $hints = [ 'NO_AUTO_COLUMNS' ];
$insertOptions = (array)$insertOptions;
$selectOptions = (array)$selectOptions;
if ( $this->cliMode && $this->isInsertSelectSafe( $insertOptions, $selectOptions ) ) {
// For massive migrations with downtime, we don't want to select everything
// into memory and OOM, so do all this native on the server side if possible.
return $this->nativeInsertSelect(
$destTable,
$srcTable,
$varMap,
$conds,
$fname,
array_diff( $insertOptions, $hints ),
$selectOptions,
$selectJoinConds
);
}
return $this->nonNativeInsertSelect(
$destTable,
$srcTable,
$varMap,
$conds,
$fname,
array_diff( $insertOptions, $hints ),
$selectOptions,
$selectJoinConds
);
}
/**
* @param array $insertOptions INSERT options
* @param array $selectOptions SELECT options
* @return bool Whether an INSERT SELECT with these options will be replication safe
* @since 1.31
*/
protected function isInsertSelectSafe( array $insertOptions, array $selectOptions ) {
return true;
}
/**
* Implementation of insertSelect() based on select() and insert()
*
* @see IDatabase::insertSelect()
* @since 1.30
* @param string $destTable
* @param string|array $srcTable
* @param array $varMap
* @param array $conds
* @param string $fname
* @param array $insertOptions
* @param array $selectOptions
* @param array $selectJoinConds
* @return bool
*/
protected function nonNativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
$fname = __METHOD__,
$insertOptions = [], $selectOptions = [], $selectJoinConds = []
) {
// For web requests, do a locking SELECT and then INSERT. This puts the SELECT burden
// on only the master (without needing row-based-replication). It also makes it easy to
// know how big the INSERT is going to be.
$fields = [];
foreach ( $varMap as $dstColumn => $sourceColumnOrSql ) {
$fields[] = $this->fieldNameWithAlias( $sourceColumnOrSql, $dstColumn );
}
$selectOptions[] = 'FOR UPDATE';
$res = $this->select(
$srcTable, implode( ',', $fields ), $conds, $fname, $selectOptions, $selectJoinConds
);
if ( !$res ) {
return false;
}
try {
$affectedRowCount = 0;
$this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
$rows = [];
$ok = true;
foreach ( $res as $row ) {
$rows[] = (array)$row;
// Avoid inserts that are too huge
if ( count( $rows ) >= $this->nonNativeInsertSelectBatchSize ) {
$ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
if ( !$ok ) {
break;
}
$affectedRowCount += $this->affectedRows();
$rows = [];
}
}
if ( $rows && $ok ) {
$ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
if ( $ok ) {
$affectedRowCount += $this->affectedRows();
}
}
if ( $ok ) {
$this->endAtomic( $fname );
$this->affectedRowCount = $affectedRowCount;
} else {
$this->cancelAtomic( $fname );
}
return $ok;
} catch ( Exception $e ) {
$this->cancelAtomic( $fname );
throw $e;
}
}
/**
* Native server-side implementation of insertSelect() for situations where
* we don't want to select everything into memory
*
* @see IDatabase::insertSelect()
* @param string $destTable
* @param string|array $srcTable
* @param array $varMap
* @param array $conds
* @param string $fname
* @param array $insertOptions
* @param array $selectOptions
* @param array $selectJoinConds
* @return bool
*/
protected function nativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
$fname = __METHOD__,
$insertOptions = [], $selectOptions = [], $selectJoinConds = []
) {
$destTable = $this->tableName( $destTable );
if ( !is_array( $insertOptions ) ) {
$insertOptions = [ $insertOptions ];
}
$insertOptions = $this->makeInsertOptions( $insertOptions );
$selectSql = $this->selectSQLText(
$srcTable,
array_values( $varMap ),
$conds,
$fname,
$selectOptions,
$selectJoinConds
);
$sql = "INSERT $insertOptions" .
" INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ') ' .
$selectSql;
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 unionConditionPermutations(
$table, $vars, array $permute_conds, $extra_conds = '', $fname = __METHOD__,
$options = [], $join_conds = []
) {
// First, build the Cartesian product of $permute_conds
$conds = [ [] ];
foreach ( $permute_conds as $field => $values ) {
if ( !$values ) {
// Skip empty $values
continue;
}
$values = array_unique( $values ); // For sanity
$newConds = [];
foreach ( $conds as $cond ) {
foreach ( $values as $value ) {
$cond[$field] = $value;
$newConds[] = $cond; // Arrays are by-value, not by-reference, so this works
}
}
$conds = $newConds;
}
$extra_conds = $extra_conds === '' ? [] : (array)$extra_conds;
// If there's just one condition and no subordering, hand off to
// selectSQLText directly.
if ( count( $conds ) === 1 &&
( !isset( $options['INNER ORDER BY'] ) || !$this->unionSupportsOrderAndLimit() )
) {
return $this->selectSQLText(
$table, $vars, $conds[0] + $extra_conds, $fname, $options, $join_conds
);
}
// Otherwise, we need to pull out the order and limit to apply after
// the union. Then build the SQL queries for each set of conditions in
// $conds. Then union them together (using UNION ALL, because the
// product *should* already be distinct).
$orderBy = $this->makeOrderBy( $options );
$limit = $options['LIMIT'] ?? null;
$offset = $options['OFFSET'] ?? false;
$all = empty( $options['NOTALL'] ) && !in_array( 'NOTALL', $options );
if ( !$this->unionSupportsOrderAndLimit() ) {
unset( $options['ORDER BY'], $options['LIMIT'], $options['OFFSET'] );
} else {
if ( array_key_exists( 'INNER ORDER BY', $options ) ) {
$options['ORDER BY'] = $options['INNER ORDER BY'];
}
if ( $limit !== null && is_numeric( $offset ) && $offset != 0 ) {
// We need to increase the limit by the offset rather than
// using the offset directly, otherwise it'll skip incorrectly
// in the subqueries.
$options['LIMIT'] = $limit + $offset;
unset( $options['OFFSET'] );
}
}
$sqls = [];
foreach ( $conds as $cond ) {
$sqls[] = $this->selectSQLText(
$table, $vars, $cond + $extra_conds, $fname, $options, $join_conds
);
}
$sql = $this->unionQueries( $sqls, $all ) . $orderBy;
if ( $limit !== null ) {
$sql = $this->limitResult( $sql, $limit, $offset );
}
return $sql;
}
public function conditional( $cond, $trueVal, $falseVal ) {
if ( is_array( $cond ) ) {
$cond = $this->makeList( $cond, self::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 wasConnectionLoss() {
return $this->wasConnectionError( $this->lastErrno() );
}
public function wasReadOnlyError() {
return false;
}
public function wasErrorReissuable() {
return (
$this->wasDeadlock() ||
$this->wasLockTimeout() ||
$this->wasConnectionLoss()
);
}
/**
* Do not use this method outside of Database/DBError classes
*
* @param int|string $errno
* @return bool Whether the given query error was a connection drop
*/
public function wasConnectionError( $errno ) {
return false;
}
/**
* @return bool Whether it is safe to assume the given error only caused statement rollback
* @note This is for backwards compatibility for callers catching DBError exceptions in
* order to ignore problems like duplicate key errors or foriegn key violations
* @since 1.31
*/
protected function wasKnownStatementRollbackError() {
return false; // don't know; it could have caused a transaction rollback
}
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 = $function( ...$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 getReplicaPos() {
# Stub
return false;
}
public function getMasterPos() {
# Stub
return false;
}
public function serverIsReadOnly() {
return false;
}
final public function onTransactionResolution( callable $callback, $fname = __METHOD__ ) {
if ( !$this->trxLevel ) {
throw new DBUnexpectedError( $this, "No transaction is active." );
}
$this->trxEndCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
}
final public function onTransactionCommitOrIdle( callable $callback, $fname = __METHOD__ ) {
if ( !$this->trxLevel && $this->getTransactionRoundId() ) {
// Start an implicit transaction similar to how query() does
$this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
$this->trxAutomatic = true;
}
$this->trxIdleCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
if ( !$this->trxLevel ) {
$this->runOnTransactionIdleCallbacks( self::TRIGGER_IDLE );
}
}
final public function onTransactionIdle( callable $callback, $fname = __METHOD__ ) {
$this->onTransactionCommitOrIdle( $callback, $fname );
}
final public function onTransactionPreCommitOrIdle( callable $callback, $fname = __METHOD__ ) {
if ( !$this->trxLevel && $this->getTransactionRoundId() ) {
// Start an implicit transaction similar to how query() does
$this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
$this->trxAutomatic = true;
}
if ( $this->trxLevel ) {
$this->trxPreCommitCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
} else {
// No transaction is active nor will start implicitly, so make one for this callback
$this->startAtomic( __METHOD__, self::ATOMIC_CANCELABLE );
try {
$callback( $this );
$this->endAtomic( __METHOD__ );
} catch ( Exception $e ) {
$this->cancelAtomic( __METHOD__ );
throw $e;
}
}
}
/**
* @return AtomicSectionIdentifier|null ID of the topmost atomic section level
*/
private function currentAtomicSectionId() {
if ( $this->trxLevel && $this->trxAtomicLevels ) {
$levelInfo = end( $this->trxAtomicLevels );
return $levelInfo[1];
}
return null;
}
/**
* @param AtomicSectionIdentifier $old
* @param AtomicSectionIdentifier $new
*/
private function reassignCallbacksForSection(
AtomicSectionIdentifier $old, AtomicSectionIdentifier $new
) {
foreach ( $this->trxPreCommitCallbacks as $key => $info ) {
if ( $info[2] === $old ) {
$this->trxPreCommitCallbacks[$key][2] = $new;
}
}
foreach ( $this->trxIdleCallbacks as $key => $info ) {
if ( $info[2] === $old ) {
$this->trxIdleCallbacks[$key][2] = $new;
}
}
foreach ( $this->trxEndCallbacks as $key => $info ) {
if ( $info[2] === $old ) {
$this->trxEndCallbacks[$key][2] = $new;
}
}
}
/**
* @param AtomicSectionIdentifier[] $sectionIds ID of an actual savepoint
* @throws UnexpectedValueException
*/
private function modifyCallbacksForCancel( array $sectionIds ) {
// Cancel the "on commit" callbacks owned by this savepoint
$this->trxIdleCallbacks = array_filter(
$this->trxIdleCallbacks,
function ( $entry ) use ( $sectionIds ) {
return !in_array( $entry[2], $sectionIds, true );
}
);
$this->trxPreCommitCallbacks = array_filter(
$this->trxPreCommitCallbacks,
function ( $entry ) use ( $sectionIds ) {
return !in_array( $entry[2], $sectionIds, true );
}
);
// Make "on resolution" callbacks owned by this savepoint to perceive a rollback
foreach ( $this->trxEndCallbacks as $key => $entry ) {
if ( in_array( $entry[2], $sectionIds, true ) ) {
$callback = $entry[0];
$this->trxEndCallbacks[$key][0] = function () use ( $callback ) {
return $callback( self::TRIGGER_ROLLBACK, $this );
};
}
}
}
final public function setTransactionListener( $name, callable $callback = null ) {
if ( $callback ) {
$this->trxRecurringCallbacks[$name] = $callback;
} else {
unset( $this->trxRecurringCallbacks[$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->trxEndCallbacksSuppressed = $suppress;
}
/**
* Actually consume and run any "on transaction idle/resolution" callbacks.
*
* This method should not be used outside of Database/LoadBalancer
*
* @param int $trigger IDatabase::TRIGGER_* constant
* @return int Number of callbacks attempted
* @since 1.20
* @throws Exception
*/
public function runOnTransactionIdleCallbacks( $trigger ) {
if ( $this->trxLevel ) { // sanity
throw new DBUnexpectedError( $this, __METHOD__ . ': a transaction is still open.' );
}
if ( $this->trxEndCallbacksSuppressed ) {
return 0;
}
$count = 0;
$autoTrx = $this->getFlag( self::DBO_TRX ); // automatic begin() enabled?
/** @var Exception $e */
$e = null; // first exception
do { // callbacks may add callbacks :)
$callbacks = array_merge(
$this->trxIdleCallbacks,
$this->trxEndCallbacks // include "transaction resolution" callbacks
);
$this->trxIdleCallbacks = []; // consumed (and recursion guard)
$this->trxEndCallbacks = []; // consumed (recursion guard)
foreach ( $callbacks as $callback ) {
++$count;
list( $phpCallback ) = $callback;
$this->clearFlag( self::DBO_TRX ); // make each query its own transaction
try {
call_user_func( $phpCallback, $trigger, $this );
} catch ( Exception $ex ) {
call_user_func( $this->errorLogger, $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__, self::FLUSHING_INTERNAL );
}
} finally {
if ( $autoTrx ) {
$this->setFlag( self::DBO_TRX ); // restore automatic begin()
} else {
$this->clearFlag( self::DBO_TRX ); // restore auto-commit
}
}
}
} while ( count( $this->trxIdleCallbacks ) );
if ( $e instanceof Exception ) {
throw $e; // re-throw any first exception
}
return $count;
}
/**
* Actually consume and run any "on transaction pre-commit" callbacks.
*
* This method should not be used outside of Database/LoadBalancer
*
* @since 1.22
* @return int Number of callbacks attempted
* @throws Exception
*/
public function runOnTransactionPreCommitCallbacks() {
$count = 0;
$e = null; // first exception
do { // callbacks may add callbacks :)
$callbacks = $this->trxPreCommitCallbacks;
$this->trxPreCommitCallbacks = []; // consumed (and recursion guard)
foreach ( $callbacks as $callback ) {
try {
++$count;
list( $phpCallback ) = $callback;
$phpCallback( $this );
} catch ( Exception $ex ) {
( $this->errorLogger )( $ex );
$e = $e ?: $ex;
}
}
} while ( count( $this->trxPreCommitCallbacks ) );
if ( $e instanceof Exception ) {
throw $e; // re-throw any first exception
}
return $count;
}
/**
* Actually run any "transaction listener" callbacks.
*
* This method should not be used outside of Database/LoadBalancer
*
* @param int $trigger IDatabase::TRIGGER_* constant
* @throws Exception
* @since 1.20
*/
public function runTransactionListenerCallbacks( $trigger ) {
if ( $this->trxEndCallbacksSuppressed ) {
return;
}
/** @var Exception $e */
$e = null; // first exception
foreach ( $this->trxRecurringCallbacks as $phpCallback ) {
try {
$phpCallback( $trigger, $this );
} catch ( Exception $ex ) {
( $this->errorLogger )( $ex );
$e = $e ?: $ex;
}
}
if ( $e instanceof Exception ) {
throw $e; // re-throw any first exception
}
}
/**
* Create a savepoint
*
* This is used internally to implement atomic sections. It should not be
* used otherwise.
*
* @since 1.31
* @param string $identifier Identifier for the savepoint
* @param string $fname Calling function name
*/
protected function doSavepoint( $identifier, $fname ) {
$this->query( 'SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
}
/**
* Release a savepoint
*
* This is used internally to implement atomic sections. It should not be
* used otherwise.
*
* @since 1.31
* @param string $identifier Identifier for the savepoint
* @param string $fname Calling function name
*/
protected function doReleaseSavepoint( $identifier, $fname ) {
$this->query( 'RELEASE SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
}
/**
* Rollback to a savepoint
*
* This is used internally to implement atomic sections. It should not be
* used otherwise.
*
* @since 1.31
* @param string $identifier Identifier for the savepoint
* @param string $fname Calling function name
*/
protected function doRollbackToSavepoint( $identifier, $fname ) {
$this->query( 'ROLLBACK TO SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
}
/**
* @param string $fname
* @return string
*/
private function nextSavepointId( $fname ) {
$savepointId = self::$SAVEPOINT_PREFIX . ++$this->trxAtomicCounter;
if ( strlen( $savepointId ) > 30 ) {
// 30 == Oracle's identifier length limit (pre 12c)
// With a 22 character prefix, that puts the highest number at 99999999.
throw new DBUnexpectedError(
$this,
'There have been an excessively large number of atomic sections in a transaction'
. " started by $this->trxFname (at $fname)"
);
}
return $savepointId;
}
final public function startAtomic(
$fname = __METHOD__, $cancelable = self::ATOMIC_NOT_CANCELABLE
) {
$savepointId = $cancelable === self::ATOMIC_CANCELABLE ? self::$NOT_APPLICABLE : null;
if ( !$this->trxLevel ) {
$this->begin( $fname, self::TRANSACTION_INTERNAL ); // sets trxAutomatic
// 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( self::DBO_TRX ) ) {
// Since writes could happen in between the topmost atomic sections as part
// of the transaction, those sections will need savepoints.
$savepointId = $this->nextSavepointId( $fname );
$this->doSavepoint( $savepointId, $fname );
} else {
$this->trxAutomaticAtomic = true;
}
} elseif ( $cancelable === self::ATOMIC_CANCELABLE ) {
$savepointId = $this->nextSavepointId( $fname );
$this->doSavepoint( $savepointId, $fname );
}
$sectionId = new AtomicSectionIdentifier;
$this->trxAtomicLevels[] = [ $fname, $sectionId, $savepointId ];
$this->queryLogger->debug( 'startAtomic: entering level ' .
( count( $this->trxAtomicLevels ) - 1 ) . " ($fname)" );
return $sectionId;
}
final public function endAtomic( $fname = __METHOD__ ) {
if ( !$this->trxLevel || !$this->trxAtomicLevels ) {
throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)." );
}
// Check if the current section matches $fname
$pos = count( $this->trxAtomicLevels ) - 1;
list( $savedFname, $sectionId, $savepointId ) = $this->trxAtomicLevels[$pos];
$this->queryLogger->debug( "endAtomic: leaving level $pos ($fname)" );
if ( $savedFname !== $fname ) {
throw new DBUnexpectedError(
$this,
"Invalid atomic section ended (got $fname but expected $savedFname)."
);
}
// Remove the last section (no need to re-index the array)
array_pop( $this->trxAtomicLevels );
if ( !$this->trxAtomicLevels && $this->trxAutomaticAtomic ) {
$this->commit( $fname, self::FLUSHING_INTERNAL );
} elseif ( $savepointId !== null && $savepointId !== self::$NOT_APPLICABLE ) {
$this->doReleaseSavepoint( $savepointId, $fname );
}
// Hoist callback ownership for callbacks in the section that just ended;
// all callbacks should have an owner that is present in trxAtomicLevels.
$currentSectionId = $this->currentAtomicSectionId();
if ( $currentSectionId ) {
$this->reassignCallbacksForSection( $sectionId, $currentSectionId );
}
}
final public function cancelAtomic(
$fname = __METHOD__, AtomicSectionIdentifier $sectionId = null
) {
if ( !$this->trxLevel || !$this->trxAtomicLevels ) {
throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)." );
}
$excisedFnames = [];
if ( $sectionId !== null ) {
// Find the (last) section with the given $sectionId
$pos = -1;
foreach ( $this->trxAtomicLevels as $i => list( $asFname, $asId, $spId ) ) {
if ( $asId === $sectionId ) {
$pos = $i;
}
}
if ( $pos < 0 ) {
throw new DBUnexpectedError( "Atomic section not found (for $fname)" );
}
// Remove all descendant sections and re-index the array
$excisedIds = [];
$len = count( $this->trxAtomicLevels );
for ( $i = $pos + 1; $i < $len; ++$i ) {
$excisedFnames[] = $this->trxAtomicLevels[$i][0];
$excisedIds[] = $this->trxAtomicLevels[$i][1];
}
$this->trxAtomicLevels = array_slice( $this->trxAtomicLevels, 0, $pos + 1 );
$this->modifyCallbacksForCancel( $excisedIds );
}
// Check if the current section matches $fname
$pos = count( $this->trxAtomicLevels ) - 1;
list( $savedFname, $savedSectionId, $savepointId ) = $this->trxAtomicLevels[$pos];
if ( $excisedFnames ) {
$this->queryLogger->debug( "cancelAtomic: canceling level $pos ($savedFname) " .
"and descendants " . implode( ', ', $excisedFnames ) );
} else {
$this->queryLogger->debug( "cancelAtomic: canceling level $pos ($savedFname)" );
}
if ( $savedFname !== $fname ) {
throw new DBUnexpectedError(
$this,
"Invalid atomic section ended (got $fname but expected $savedFname)."
);
}
// Remove the last section (no need to re-index the array)
array_pop( $this->trxAtomicLevels );
$this->modifyCallbacksForCancel( [ $savedSectionId ] );
if ( $savepointId !== null ) {
// Rollback the transaction to the state just before this atomic section
if ( $savepointId === self::$NOT_APPLICABLE ) {
$this->rollback( $fname, self::FLUSHING_INTERNAL );
} else {
$this->doRollbackToSavepoint( $savepointId, $fname );
$this->trxStatus = self::STATUS_TRX_OK; // no exception; recovered
$this->trxStatusIgnoredCause = null;
}
} elseif ( $this->trxStatus > self::STATUS_TRX_ERROR ) {
// Put the transaction into an error state if it's not already in one
$this->trxStatus = self::STATUS_TRX_ERROR;
$this->trxStatusCause = new DBUnexpectedError(
$this,
"Uncancelable atomic section canceled (got $fname)."
);
}
$this->affectedRowCount = 0; // for the sake of consistency
}
final public function doAtomicSection(
$fname, callable $callback, $cancelable = self::ATOMIC_NOT_CANCELABLE
) {
$sectionId = $this->startAtomic( $fname, $cancelable );
try {
$res = $callback( $this, $fname );
} catch ( Exception $e ) {
$this->cancelAtomic( $fname, $sectionId );
throw $e;
}
$this->endAtomic( $fname );
return $res;
}
final public function begin( $fname = __METHOD__, $mode = self::TRANSACTION_EXPLICIT ) {
static $modes = [ self::TRANSACTION_EXPLICIT, self::TRANSACTION_INTERNAL ];
if ( !in_array( $mode, $modes, true ) ) {
throw new DBUnexpectedError( $this, "$fname: invalid mode parameter '$mode'." );
}
// Protect against mismatched atomic section, transaction nesting, and snapshot loss
if ( $this->trxLevel ) {
if ( $this->trxAtomicLevels ) {
$levels = $this->flatAtomicSectionList();
$msg = "$fname: Got explicit BEGIN while atomic section(s) $levels are open.";
throw new DBUnexpectedError( $this, $msg );
} elseif ( !$this->trxAutomatic ) {
$msg = "$fname: Explicit transaction already active (from {$this->trxFname}).";
throw new DBUnexpectedError( $this, $msg );
} else {
$msg = "$fname: Implicit transaction already active (from {$this->trxFname}).";
throw new DBUnexpectedError( $this, $msg );
}
} elseif ( $this->getFlag( self::DBO_TRX ) && $mode !== self::TRANSACTION_INTERNAL ) {
$msg = "$fname: Implicit transaction expected (DBO_TRX set).";
throw new DBUnexpectedError( $this, $msg );
}
// Avoid fatals if close() was called
$this->assertOpen();
$this->doBegin( $fname );
$this->trxStatus = self::STATUS_TRX_OK;
$this->trxStatusIgnoredCause = null;
$this->trxAtomicCounter = 0;
$this->trxTimestamp = microtime( true );
$this->trxFname = $fname;
$this->trxDoneWrites = false;
$this->trxAutomaticAtomic = false;
$this->trxAtomicLevels = [];
$this->trxShortId = sprintf( '%06x', mt_rand( 0, 0xffffff ) );
$this->trxWriteDuration = 0.0;
$this->trxWriteQueryCount = 0;
$this->trxWriteAffectedRows = 0;
$this->trxWriteAdjDuration = 0.0;
$this->trxWriteAdjQueryCount = 0;
$this->trxWriteCallers = [];
// First SELECT after BEGIN will establish the snapshot in REPEATABLE-READ.
// Get an estimate of the replication lag before any such queries.
$this->trxReplicaLag = null; // clear cached value first
$this->trxReplicaLag = $this->getApproximateLagStatus()['lag'];
// T147697: make explicitTrxActive() return true until begin() finishes. This way, no
// caller will think its OK to muck around with the transaction just because startAtomic()
// has not yet completed (e.g. setting trxAtomicLevels).
$this->trxAutomatic = ( $mode === self::TRANSACTION_INTERNAL );
}
/**
* Issues the BEGIN command to the database server.
*
* @see Database::begin()
* @param string $fname
*/
protected function doBegin( $fname ) {
$this->query( 'BEGIN', $fname );
$this->trxLevel = 1;
}
final public function commit( $fname = __METHOD__, $flush = self::FLUSHING_ONE ) {
static $modes = [ self::FLUSHING_ONE, self::FLUSHING_ALL_PEERS, self::FLUSHING_INTERNAL ];
if ( !in_array( $flush, $modes, true ) ) {
throw new DBUnexpectedError( $this, "$fname: invalid flush parameter '$flush'." );
}
if ( $this->trxLevel && $this->trxAtomicLevels ) {
// There are still atomic sections open; this cannot be ignored
$levels = $this->flatAtomicSectionList();
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->trxLevel ) {
return; // nothing to do
} elseif ( !$this->trxAutomatic ) {
throw new DBUnexpectedError(
$this,
"$fname: Flushing an explicit transaction, getting out of sync."
);
}
} else {
if ( !$this->trxLevel ) {
$this->queryLogger->error(
"$fname: No transaction to commit, something got out of sync." );
return; // nothing to do
} elseif ( $this->trxAutomatic ) {
throw new DBUnexpectedError(
$this,
"$fname: Expected mass commit of all peer transactions (DBO_TRX set)."
);
}
}
// Avoid fatals if close() was called
$this->assertOpen();
$this->runOnTransactionPreCommitCallbacks();
$writeTime = $this->pendingWriteQueryDuration( self::ESTIMATE_DB_APPLY );
$this->doCommit( $fname );
$this->trxStatus = self::STATUS_TRX_NONE;
if ( $this->trxDoneWrites ) {
$this->lastWriteTime = microtime( true );
$this->trxProfiler->transactionWritingOut(
$this->server,
$this->getDomainID(),
$this->trxShortId,
$writeTime,
$this->trxWriteAffectedRows
);
}
// With FLUSHING_ALL_PEERS, callbacks will be explicitly run later
if ( $flush !== self::FLUSHING_ALL_PEERS ) {
$this->runOnTransactionIdleCallbacks( self::TRIGGER_COMMIT );
$this->runTransactionListenerCallbacks( self::TRIGGER_COMMIT );
}
}
/**
* Issues the COMMIT command to the database server.
*
* @see Database::commit()
* @param string $fname
*/
protected function doCommit( $fname ) {
if ( $this->trxLevel ) {
$this->query( 'COMMIT', $fname );
$this->trxLevel = 0;
}
}
final public function rollback( $fname = __METHOD__, $flush = '' ) {
$trxActive = $this->trxLevel;
if ( $flush !== self::FLUSHING_INTERNAL && $flush !== self::FLUSHING_ALL_PEERS ) {
if ( $this->getFlag( self::DBO_TRX ) ) {
throw new DBUnexpectedError(
$this,
"$fname: Expected mass rollback of all peer transactions (DBO_TRX set)."
);
}
}
if ( $trxActive ) {
// Avoid fatals if close() was called
$this->assertOpen();
$writeTime = $this->pendingWriteQueryDuration( self::ESTIMATE_DB_APPLY );
$this->doRollback( $fname );
$this->trxStatus = self::STATUS_TRX_NONE;
$this->trxAtomicLevels = [];
if ( $this->trxDoneWrites ) {
$this->trxProfiler->transactionWritingOut(
$this->server,
$this->getDomainID(),
$this->trxShortId,
$writeTime,
$this->trxWriteAffectedRows
);
}
}
// Clear any commit-dependant callbacks. They might even be present
// only due to transaction rounds, with no SQL transaction being active
$this->trxIdleCallbacks = [];
$this->trxPreCommitCallbacks = [];
// With FLUSHING_ALL_PEERS, callbacks will be explicitly run later
if ( $trxActive && $flush !== self::FLUSHING_ALL_PEERS ) {
try {
$this->runOnTransactionIdleCallbacks( self::TRIGGER_ROLLBACK );
} catch ( Exception $e ) {
// already logged; finish and let LoadBalancer move on during mass-rollback
}
try {
$this->runTransactionListenerCallbacks( self::TRIGGER_ROLLBACK );
} catch ( Exception $e ) {
// already logged; let LoadBalancer move on during mass-rollback
}
$this->affectedRowCount = 0; // for the sake of consistency
}
}
/**
* Issues the ROLLBACK command to the database server.
*
* @see Database::rollback()
* @param string $fname
*/
protected function doRollback( $fname ) {
if ( $this->trxLevel ) {
# Disconnects cause rollback anyway, so ignore those errors
$ignoreErrors = true;
$this->query( 'ROLLBACK', $fname, $ignoreErrors );
$this->trxLevel = 0;
}
}
public function flushSnapshot( $fname = __METHOD__ ) {
if ( $this->writesOrCallbacksPending() || $this->explicitTrxActive() ) {
// This only flushes transactions to clear snapshots, not to write data
$fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
throw new DBUnexpectedError(
$this,
"$fname: Cannot flush snapshot because writes are pending ($fnames)."
);
}
$this->commit( $fname, self::FLUSHING_INTERNAL );
}
public function explicitTrxActive() {
return $this->trxLevel && ( $this->trxAtomicLevels || !$this->trxAutomatic );
}
public function duplicateTableStructure(
$oldName, $newName, $temporary = false, $fname = __METHOD__
) {
throw new RuntimeException( __METHOD__ . ' is not implemented in descendant class' );
}
public function listTables( $prefix = null, $fname = __METHOD__ ) {
throw new RuntimeException( __METHOD__ . ' is not implemented in descendant class' );
}
public function listViews( $prefix = null, $fname = __METHOD__ ) {
throw new RuntimeException( __METHOD__ . ' is not implemented in descendant class' );
}
public function timestamp( $ts = 0 ) {
$t = new ConvertibleTimestamp( $ts );
// Let errors bubble up to avoid putting garbage in the DB
return $t->getTimestamp( TS_MW );
}
public function timestampOrNull( $ts = null ) {
if ( is_null( $ts ) ) {
return null;
} else {
return $this->timestamp( $ts );
}
}
public function affectedRows() {
return ( $this->affectedRowCount === null )
? $this->fetchAffectedRowCount() // default to driver value
: $this->affectedRowCount;
}
/**
* @return int Number of retrieved rows according to the driver
*/
abstract protected function fetchAffectedRowCount();
/**
* 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, Database::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 $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->rttEstimate > 0 ) {
$rtt = $this->rttEstimate;
return true; // don't care about $rtt
}
}
// This will reconnect if possible or return false if not
$this->clearFlag( self::DBO_TRX, self::REMEMBER_PRIOR );
$ok = ( $this->query( self::PING_QUERY, __METHOD__, true ) !== false );
$this->restoreFlags( self::RESTORE_PRIOR );
if ( $ok ) {
$rtt = $this->rttEstimate;
}
return $ok;
}
/**
* Close any existing (dead) database connection and open a new connection
*
* @param string $fname
* @return bool True if new connection is opened successfully, false if error
*/
protected function replaceLostConnection( $fname ) {
$this->closeConnection();
$this->opened = false;
$this->conn = false;
try {
$this->open(
$this->server,
$this->user,
$this->password,
$this->getDBname(),
$this->dbSchema(),
$this->tablePrefix()
);
$this->lastPing = microtime( true );
$ok = true;
$this->connLogger->warning(
$fname . ': lost connection to {dbserver}; reconnected',
[
'dbserver' => $this->getServer(),
'trace' => ( new RuntimeException() )->getTraceAsString()
]
);
} catch ( DBConnectionError $e ) {
$ok = false;
$this->connLogger->error(
$fname . ': lost connection to {dbserver} permanently',
[ 'dbserver' => $this->getServer() ]
);
}
$this->handleSessionLoss();
return $ok;
}
public function getSessionLagStatus() {
return $this->getRecordedTransactionLagStatus() ?: $this->getApproximateLagStatus();
}
/**
* Get the replica DB 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.
*
* This returns null if the lag status for this transaction was not yet recorded.
*
* @return array|null ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)
* @since 1.27
*/
final protected function getRecordedTransactionLagStatus() {
return ( $this->trxLevel && $this->trxReplicaLag !== null )
? [ 'lag' => $this->trxReplicaLag, 'since' => $this->trxTimestamp() ]
: null;
}
/**
* Get a replica DB lag estimate for this server
*
* @return array ('lag': seconds or false on error, 'since': UNIX timestamp of estimate)
* @since 1.27
*/
protected function getApproximateLagStatus() {
return [
'lag' => $this->getLBInfo( 'replica' ) ? $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|null $db2 [optional]
* @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
* @throws DBError
* @since 1.27
*/
public static function getCacheSetOptions( IDatabase $db1, IDatabase $db2 = null ) {
$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;
}
public 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 ) {
}
public function sourceFile(
$filename,
callable $lineCallback = null,
callable $resultCallback = null,
$fname = false,
callable $inputCallback = null
) {
Wikimedia\suppressWarnings();
$fp = fopen( $filename, 'r' );
Wikimedia\restoreWarnings();
if ( false === $fp ) {
throw new RuntimeException( "Could not open \"{$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;
}
public function setSchemaVars( $vars ) {
$this->schemaVars = $vars;
}
public function sourceStream(
$fp,
callable $lineCallback = null,
callable $resultCallback = null,
$fname = __METHOD__,
callable $inputCallback = null
) {
$delimiterReset = new ScopedCallback(
function ( $delimiter ) {
$this->delimiter = $delimiter;
},
[ $this->delimiter ]
);
$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 ) {
$callbackResult = $inputCallback( $cmd );
if ( is_string( $callbackResult ) || !$callbackResult ) {
$cmd = $callbackResult;
}
}
if ( $cmd ) {
$res = $this->query( $cmd, $fname );
if ( $resultCallback ) {
$resultCallback( $res, $this );
}
if ( false === $res ) {
$err = $this->lastError();
return "Query \"{$cmd}\" failed with error code \"$err\".\n";
}
}
$cmd = '';
}
}
ScopedCallback::consume( $delimiterReset );
return true;
}
/**
* Called by sourceStream() to check if we've reached a statement end
*
* @param string &$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->schemaVars ) {
return $this->schemaVars;
} 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 ) {
// RDBMs methods for checking named locks may or may not count this thread itself.
// In MySQL, IS_FREE_LOCK() returns 0 if the thread already has the lock. This is
// the behavior choosen by the interface for this method.
return !isset( $this->namedLocksHeld[$lockName] );
}
public function lock( $lockName, $method, $timeout = 5 ) {
$this->namedLocksHeld[$lockName] = 1;
return true;
}
public function unlock( $lockName, $method ) {
unset( $this->namedLocksHeld[$lockName] );
return true;
}
public function getScopedLockAndFlush( $lockKey, $fname, $timeout ) {
if ( $this->writesOrCallbacksPending() ) {
// This only flushes transactions to clear snapshots, not to write data
$fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
throw new DBUnexpectedError(
$this,
"$fname: Cannot flush pre-lock snapshot because writes are pending ($fnames)."
);
}
if ( !$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 );
},
$fname
);
} else {
$this->unlock( $lockKey, $fname );
}
} );
$this->commit( $fname, self::FLUSHING_INTERNAL );
return $unlocker;
}
public function namedLocksEnqueue() {
return false;
}
public function tableLocksHaveTransactionScope() {
return true;
}
final public function lockTables( array $read, array $write, $method ) {
if ( $this->writesOrCallbacksPending() ) {
throw new DBUnexpectedError( $this, "Transaction writes or callbacks still pending." );
}
if ( $this->tableLocksHaveTransactionScope() ) {
$this->startAtomic( $method );
}
return $this->doLockTables( $read, $write, $method );
}
/**
* Helper function for lockTables() that handles the actual table locking
*
* @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
* @return true
*/
protected function doLockTables( array $read, array $write, $method ) {
return true;
}
final public function unlockTables( $method ) {
if ( $this->tableLocksHaveTransactionScope() ) {
$this->endAtomic( $method );
return true; // locks released on COMMIT/ROLLBACK
}
return $this->doUnlockTables( $method );
}
/**
* Helper function for unlockTables() that handles the actual table unlocking
*
* @param string $method Name of caller
* @return true
*/
protected function doUnlockTables( $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 ) . " CASCADE";
return $this->query( $sql, $fName );
}
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 ) {
if ( $expiry == '' || $expiry == 'infinity' || $expiry == $this->getInfinity() ) {
return 'infinity';
}
return ConvertibleTimestamp::convert( $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;
}
public function setTableAliases( array $aliases ) {
$this->tableAliases = $aliases;
}
public function setIndexAliases( array $aliases ) {
$this->indexAliases = $aliases;
}
/**
* Get the underlying binding connection handle
*
* Makes sure the connection resource is set (disconnects and ping() failure can unset it).
* This catches broken callers than catch and ignore disconnection exceptions.
* Unlike checking isOpen(), this is safe to call inside of open().
*
* @return mixed
* @throws DBUnexpectedError
* @since 1.26
*/
protected function getBindingHandle() {
if ( !$this->conn ) {
throw new DBUnexpectedError(
$this,
'DB connection was already closed or the connection dropped.'
);
}
return $this->conn;
}
/**
* @since 1.19
* @return string
*/
public function __toString() {
return (string)$this->conn;
}
/**
* Make sure that copies do not share the same client binding handle
* @throws DBConnectionError
*/
public function __clone() {
$this->connLogger->warning(
"Cloning " . static::class . " is not recommended; forking connection:\n" .
( new RuntimeException() )->getTraceAsString()
);
if ( $this->isOpen() ) {
// Open a new connection resource without messing with the old one
$this->opened = false;
$this->conn = false;
$this->trxEndCallbacks = []; // don't copy
$this->handleSessionLoss(); // no trx or locks anymore
$this->open(
$this->server,
$this->user,
$this->password,
$this->getDBname(),
$this->dbSchema(),
$this->tablePrefix()
);
$this->lastPing = microtime( true );
}
}
/**
* 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 RuntimeException( 'Database serialization may cause problems, since ' .
'the connection is not restored on wakeup.' );
}
/**
* Run a few simple sanity checks and close dangling connections
*/
public function __destruct() {
if ( $this->trxLevel && $this->trxDoneWrites ) {
trigger_error( "Uncommitted DB writes (transaction from {$this->trxFname})." );
}
$danglingWriters = $this->pendingWriteAndCallbackCallers();
if ( $danglingWriters ) {
$fnames = implode( ', ', $danglingWriters );
trigger_error( "DB transaction writes or callbacks still pending ($fnames)." );
}
if ( $this->conn ) {
// Avoid connection leaks for sanity. Normally, resources close at script completion.
// The connection might already be closed in zend/hhvm by now, so suppress warnings.
Wikimedia\suppressWarnings();
$this->closeConnection();
Wikimedia\restoreWarnings();
$this->conn = false;
$this->opened = false;
}
}
}
/**
* @deprecated since 1.28
*/
class_alias( Database::class, 'DatabaseBase' );
/**
* @deprecated since 1.29
*/
class_alias( Database::class, 'Database' );
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