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Merge "resourceloader: Rewrite the minify.php maintenance script"
[lhc/web/wiklou.git] / includes / libs / rdbms / database / Database.php
1 <?php
2 /**
3 * @defgroup Database Database
4 *
5 * This file deals with database interface functions
6 * and query specifics/optimisations.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21 * http://www.gnu.org/copyleft/gpl.html
22 *
23 * @file
24 * @ingroup Database
25 */
26 namespace Wikimedia\Rdbms;
27
28 use Psr\Log\LoggerAwareInterface;
29 use Psr\Log\LoggerInterface;
30 use Psr\Log\NullLogger;
31 use Wikimedia\ScopedCallback;
32 use Wikimedia\Timestamp\ConvertibleTimestamp;
33 use Wikimedia\AtEase\AtEase;
34 use BagOStuff;
35 use HashBagOStuff;
36 use LogicException;
37 use InvalidArgumentException;
38 use UnexpectedValueException;
39 use Exception;
40 use RuntimeException;
41 use Throwable;
42
43 /**
44 * Relational database abstraction object
45 *
46 * @ingroup Database
47 * @since 1.28
48 */
49 abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAwareInterface {
50 /** @var string Server that this instance is currently connected to */
51 protected $server;
52 /** @var string User that this instance is currently connected under the name of */
53 protected $user;
54 /** @var string Password used to establish the current connection */
55 protected $password;
56 /** @var array[] Map of (table => (dbname, schema, prefix) map) */
57 protected $tableAliases = [];
58 /** @var string[] Map of (index alias => index) */
59 protected $indexAliases = [];
60 /** @var bool Whether this PHP instance is for a CLI script */
61 protected $cliMode;
62 /** @var string Agent name for query profiling */
63 protected $agent;
64 /** @var int Bit field of class DBO_* constants */
65 protected $flags;
66 /** @var array LoadBalancer tracking information */
67 protected $lbInfo = [];
68 /** @var array|bool Variables use for schema element placeholders */
69 protected $schemaVars = false;
70 /** @var array Parameters used by initConnection() to establish a connection */
71 protected $connectionParams = [];
72 /** @var array SQL variables values to use for all new connections */
73 protected $connectionVariables = [];
74 /** @var string Current SQL query delimiter */
75 protected $delimiter = ';';
76 /** @var string|bool|null Stashed value of html_errors INI setting */
77 protected $htmlErrors;
78 /** @var int Row batch size to use for emulated INSERT SELECT queries */
79 protected $nonNativeInsertSelectBatchSize = 10000;
80
81 /** @var BagOStuff APC cache */
82 protected $srvCache;
83 /** @var LoggerInterface */
84 protected $connLogger;
85 /** @var LoggerInterface */
86 protected $queryLogger;
87 /** @var callable Error logging callback */
88 protected $errorLogger;
89 /** @var callable Deprecation logging callback */
90 protected $deprecationLogger;
91 /** @var callable|null */
92 protected $profiler;
93 /** @var TransactionProfiler */
94 protected $trxProfiler;
95 /** @var DatabaseDomain */
96 protected $currentDomain;
97 /** @var object|resource|null Database connection */
98 protected $conn;
99
100 /** @var IDatabase|null Lazy handle to the master DB this server replicates from */
101 private $lazyMasterHandle;
102
103 /** @var array Map of (name => 1) for locks obtained via lock() */
104 protected $sessionNamedLocks = [];
105 /** @var array Map of (table name => 1) for TEMPORARY tables */
106 protected $sessionTempTables = [];
107
108 /** @var string ID of the active transaction or the empty string otherwise */
109 protected $trxShortId = '';
110 /** @var int Transaction status */
111 protected $trxStatus = self::STATUS_TRX_NONE;
112 /** @var Exception|null The last error that caused the status to become STATUS_TRX_ERROR */
113 protected $trxStatusCause;
114 /** @var array|null Error details of the last statement-only rollback */
115 private $trxStatusIgnoredCause;
116 /** @var float|null UNIX timestamp at the time of BEGIN for the last transaction */
117 private $trxTimestamp = null;
118 /** @var float Replication lag estimate at the time of BEGIN for the last transaction */
119 private $trxReplicaLag = null;
120 /** @var string Name of the function that start the last transaction */
121 private $trxFname = null;
122 /** @var bool Whether possible write queries were done in the last transaction started */
123 private $trxDoneWrites = false;
124 /** @var bool Whether the current transaction was started implicitly due to DBO_TRX */
125 private $trxAutomatic = false;
126 /** @var int Counter for atomic savepoint identifiers (reset with each transaction) */
127 private $trxAtomicCounter = 0;
128 /** @var array List of (name, unique ID, savepoint ID) for each active atomic section level */
129 private $trxAtomicLevels = [];
130 /** @var bool Whether the current transaction was started implicitly by startAtomic() */
131 private $trxAutomaticAtomic = false;
132 /** @var string[] Write query callers of the current transaction */
133 private $trxWriteCallers = [];
134 /** @var float Seconds spent in write queries for the current transaction */
135 private $trxWriteDuration = 0.0;
136 /** @var int Number of write queries for the current transaction */
137 private $trxWriteQueryCount = 0;
138 /** @var int Number of rows affected by write queries for the current transaction */
139 private $trxWriteAffectedRows = 0;
140 /** @var float Like trxWriteQueryCount but excludes lock-bound, easy to replicate, queries */
141 private $trxWriteAdjDuration = 0.0;
142 /** @var int Number of write queries counted in trxWriteAdjDuration */
143 private $trxWriteAdjQueryCount = 0;
144 /** @var array[] List of (callable, method name, atomic section id) */
145 private $trxIdleCallbacks = [];
146 /** @var array[] List of (callable, method name, atomic section id) */
147 private $trxPreCommitCallbacks = [];
148 /** @var array[] List of (callable, method name, atomic section id) */
149 private $trxEndCallbacks = [];
150 /** @var array[] List of (callable, method name, atomic section id) */
151 private $trxSectionCancelCallbacks = [];
152 /** @var callable[] Map of (name => callable) */
153 private $trxRecurringCallbacks = [];
154 /** @var bool Whether to suppress triggering of transaction end callbacks */
155 private $trxEndCallbacksSuppressed = false;
156
157 /** @var int[] Prior flags member variable values */
158 private $priorFlags = [];
159
160 /** @var integer|null Rows affected by the last query to query() or its CRUD wrappers */
161 protected $affectedRowCount;
162
163 /** @var float UNIX timestamp */
164 private $lastPing = 0.0;
165 /** @var string The last SQL query attempted */
166 private $lastQuery = '';
167 /** @var float|bool UNIX timestamp of last write query */
168 private $lastWriteTime = false;
169 /** @var string|bool */
170 private $lastPhpError = false;
171 /** @var float Query rount trip time estimate */
172 private $lastRoundTripEstimate = 0.0;
173
174 /** @var string Lock granularity is on the level of the entire database */
175 const ATTR_DB_LEVEL_LOCKING = 'db-level-locking';
176 /** @var string The SCHEMA keyword refers to a grouping of tables in a database */
177 const ATTR_SCHEMAS_AS_TABLE_GROUPS = 'supports-schemas';
178
179 /** @var int New Database instance will not be connected yet when returned */
180 const NEW_UNCONNECTED = 0;
181 /** @var int New Database instance will already be connected when returned */
182 const NEW_CONNECTED = 1;
183
184 /** @var int Transaction is in a error state requiring a full or savepoint rollback */
185 const STATUS_TRX_ERROR = 1;
186 /** @var int Transaction is active and in a normal state */
187 const STATUS_TRX_OK = 2;
188 /** @var int No transaction is active */
189 const STATUS_TRX_NONE = 3;
190
191 /** @var string Idiom used when a cancelable atomic section started the transaction */
192 private static $NOT_APPLICABLE = 'n/a';
193 /** @var string Prefix to the atomic section counter used to make savepoint IDs */
194 private static $SAVEPOINT_PREFIX = 'wikimedia_rdbms_atomic';
195
196 /** @var int Writes to this temporary table do not affect lastDoneWrites() */
197 private static $TEMP_NORMAL = 1;
198 /** @var int Writes to this temporary table effect lastDoneWrites() */
199 private static $TEMP_PSEUDO_PERMANENT = 2;
200
201 /** @var int Number of times to re-try an operation in case of deadlock */
202 private static $DEADLOCK_TRIES = 4;
203 /** @var int Minimum time to wait before retry, in microseconds */
204 private static $DEADLOCK_DELAY_MIN = 500000;
205 /** @var int Maximum time to wait before retry */
206 private static $DEADLOCK_DELAY_MAX = 1500000;
207
208 /** @var int How long before it is worth doing a dummy query to test the connection */
209 private static $PING_TTL = 1.0;
210 /** @var string Dummy SQL query */
211 private static $PING_QUERY = 'SELECT 1 AS ping';
212
213 /** @var float Guess of how many seconds it takes to replicate a small insert */
214 private static $TINY_WRITE_SEC = 0.010;
215 /** @var float Consider a write slow if it took more than this many seconds */
216 private static $SLOW_WRITE_SEC = 0.500;
217 /** @var float Assume an insert of this many rows or less should be fast to replicate */
218 private static $SMALL_WRITE_ROWS = 100;
219
220 /** @var string[] List of DBO_* flags that can be changed after connection */
221 protected static $MUTABLE_FLAGS = [
222 'DBO_DEBUG',
223 'DBO_NOBUFFER',
224 'DBO_TRX',
225 'DBO_DDLMODE',
226 ];
227 /** @var int Bit field of all DBO_* flags that can be changed after connection */
228 protected static $DBO_MUTABLE = (
229 self::DBO_DEBUG | self::DBO_NOBUFFER | self::DBO_TRX | self::DBO_DDLMODE
230 );
231
232 /**
233 * @note exceptions for missing libraries/drivers should be thrown in initConnection()
234 * @param array $params Parameters passed from Database::factory()
235 */
236 protected function __construct( array $params ) {
237 foreach ( [ 'host', 'user', 'password', 'dbname', 'schema', 'tablePrefix' ] as $name ) {
238 $this->connectionParams[$name] = $params[$name];
239 }
240
241 $this->cliMode = $params['cliMode'];
242 // Agent name is added to SQL queries in a comment, so make sure it can't break out
243 $this->agent = str_replace( '/', '-', $params['agent'] );
244
245 $this->flags = $params['flags'];
246 if ( $this->flags & self::DBO_DEFAULT ) {
247 if ( $this->cliMode ) {
248 $this->flags &= ~self::DBO_TRX;
249 } else {
250 $this->flags |= self::DBO_TRX;
251 }
252 }
253 // Disregard deprecated DBO_IGNORE flag (T189999)
254 $this->flags &= ~self::DBO_IGNORE;
255
256 $this->connectionVariables = $params['variables'];
257
258 $this->srvCache = $params['srvCache'] ?? new HashBagOStuff();
259
260 $this->profiler = is_callable( $params['profiler'] ) ? $params['profiler'] : null;
261 $this->trxProfiler = $params['trxProfiler'];
262 $this->connLogger = $params['connLogger'];
263 $this->queryLogger = $params['queryLogger'];
264 $this->errorLogger = $params['errorLogger'];
265 $this->deprecationLogger = $params['deprecationLogger'];
266
267 if ( isset( $params['nonNativeInsertSelectBatchSize'] ) ) {
268 $this->nonNativeInsertSelectBatchSize = $params['nonNativeInsertSelectBatchSize'];
269 }
270
271 // Set initial dummy domain until open() sets the final DB/prefix
272 $this->currentDomain = new DatabaseDomain(
273 $params['dbname'] != '' ? $params['dbname'] : null,
274 $params['schema'] != '' ? $params['schema'] : null,
275 $params['tablePrefix']
276 );
277 }
278
279 /**
280 * Initialize the connection to the database over the wire (or to local files)
281 *
282 * @throws LogicException
283 * @throws InvalidArgumentException
284 * @throws DBConnectionError
285 * @since 1.31
286 */
287 final public function initConnection() {
288 if ( $this->isOpen() ) {
289 throw new LogicException( __METHOD__ . ': already connected' );
290 }
291 // Establish the connection
292 $this->doInitConnection();
293 }
294
295 /**
296 * Actually connect to the database over the wire (or to local files)
297 *
298 * @throws DBConnectionError
299 * @since 1.31
300 */
301 protected function doInitConnection() {
302 $this->open(
303 $this->connectionParams['host'],
304 $this->connectionParams['user'],
305 $this->connectionParams['password'],
306 $this->connectionParams['dbname'],
307 $this->connectionParams['schema'],
308 $this->connectionParams['tablePrefix']
309 );
310 }
311
312 /**
313 * Open a new connection to the database (closing any existing one)
314 *
315 * @param string|null $server Database server host
316 * @param string|null $user Database user name
317 * @param string|null $password Database user password
318 * @param string|null $dbName Database name
319 * @param string|null $schema Database schema name
320 * @param string $tablePrefix Table prefix
321 * @throws DBConnectionError
322 */
323 abstract protected function open( $server, $user, $password, $dbName, $schema, $tablePrefix );
324
325 /**
326 * Construct a Database subclass instance given a database type and parameters
327 *
328 * This also connects to the database immediately upon object construction
329 *
330 * @param string $type A possible DB type (sqlite, mysql, postgres,...)
331 * @param array $params Parameter map with keys:
332 * - host : The hostname of the DB server
333 * - user : The name of the database user the client operates under
334 * - password : The password for the database user
335 * - dbname : The name of the database to use where queries do not specify one.
336 * The database must exist or an error might be thrown. Setting this to the empty string
337 * will avoid any such errors and make the handle have no implicit database scope. This is
338 * useful for queries like SHOW STATUS, CREATE DATABASE, or DROP DATABASE. Note that a
339 * "database" in Postgres is rougly equivalent to an entire MySQL server. This the domain
340 * in which user names and such are defined, e.g. users are database-specific in Postgres.
341 * - schema : The database schema to use (if supported). A "schema" in Postgres is roughly
342 * equivalent to a "database" in MySQL. Note that MySQL and SQLite do not use schemas.
343 * - tablePrefix : Optional table prefix that is implicitly added on to all table names
344 * recognized in queries. This can be used in place of schemas for handle site farms.
345 * - flags : Optional bit field of DBO_* constants that define connection, protocol,
346 * buffering, and transaction behavior. It is STRONGLY adviced to leave the DBO_DEFAULT
347 * flag in place UNLESS this this database simply acts as a key/value store.
348 * - driver: Optional name of a specific DB client driver. For MySQL, there is only the
349 * 'mysqli' driver; the old one 'mysql' has been removed.
350 * - variables: Optional map of session variables to set after connecting. This can be
351 * used to adjust lock timeouts or encoding modes and the like.
352 * - connLogger: Optional PSR-3 logger interface instance.
353 * - queryLogger: Optional PSR-3 logger interface instance.
354 * - profiler : Optional callback that takes a section name argument and returns
355 * a ScopedCallback instance that ends the profile section in its destructor.
356 * These will be called in query(), using a simplified version of the SQL that
357 * also includes the agent as a SQL comment.
358 * - trxProfiler: Optional TransactionProfiler instance.
359 * - errorLogger: Optional callback that takes an Exception and logs it.
360 * - deprecationLogger: Optional callback that takes a string and logs it.
361 * - cliMode: Whether to consider the execution context that of a CLI script.
362 * - agent: Optional name used to identify the end-user in query profiling/logging.
363 * - srvCache: Optional BagOStuff instance to an APC-style cache.
364 * - nonNativeInsertSelectBatchSize: Optional batch size for non-native INSERT SELECT emulation.
365 * @param int $connect One of the class constants (NEW_CONNECTED, NEW_UNCONNECTED) [optional]
366 * @return Database|null If the database driver or extension cannot be found
367 * @throws InvalidArgumentException If the database driver or extension cannot be found
368 * @since 1.18
369 */
370 final public static function factory( $type, $params = [], $connect = self::NEW_CONNECTED ) {
371 $class = self::getClass( $type, $params['driver'] ?? null );
372
373 if ( class_exists( $class ) && is_subclass_of( $class, IDatabase::class ) ) {
374 $params += [
375 'host' => null,
376 'user' => null,
377 'password' => null,
378 'dbname' => null,
379 'schema' => null,
380 'tablePrefix' => '',
381 'flags' => 0,
382 'variables' => [],
383 'cliMode' => ( PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg' ),
384 'agent' => basename( $_SERVER['SCRIPT_NAME'] ) . '@' . gethostname()
385 ];
386
387 $normalizedParams = [
388 // Configuration
389 'host' => strlen( $params['host'] ) ? $params['host'] : null,
390 'user' => strlen( $params['user'] ) ? $params['user'] : null,
391 'password' => is_string( $params['password'] ) ? $params['password'] : null,
392 'dbname' => strlen( $params['dbname'] ) ? $params['dbname'] : null,
393 'schema' => strlen( $params['schema'] ) ? $params['schema'] : null,
394 'tablePrefix' => (string)$params['tablePrefix'],
395 'flags' => (int)$params['flags'],
396 'variables' => $params['variables'],
397 'cliMode' => (bool)$params['cliMode'],
398 'agent' => (string)$params['agent'],
399 // Objects and callbacks
400 'profiler' => $params['profiler'] ?? null,
401 'trxProfiler' => $params['trxProfiler'] ?? new TransactionProfiler(),
402 'connLogger' => $params['connLogger'] ?? new NullLogger(),
403 'queryLogger' => $params['queryLogger'] ?? new NullLogger(),
404 'errorLogger' => $params['errorLogger'] ?? function ( Exception $e ) {
405 trigger_error( get_class( $e ) . ': ' . $e->getMessage(), E_USER_WARNING );
406 },
407 'deprecationLogger' => $params['deprecationLogger'] ?? function ( $msg ) {
408 trigger_error( $msg, E_USER_DEPRECATED );
409 }
410 ] + $params;
411
412 /** @var Database $conn */
413 $conn = new $class( $normalizedParams );
414 if ( $connect === self::NEW_CONNECTED ) {
415 $conn->initConnection();
416 }
417 } else {
418 $conn = null;
419 }
420
421 return $conn;
422 }
423
424 /**
425 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
426 * @param string|null $driver Optional name of a specific DB client driver
427 * @return array Map of (Database::ATTR_* constant => value) for all such constants
428 * @throws InvalidArgumentException
429 * @since 1.31
430 */
431 final public static function attributesFromType( $dbType, $driver = null ) {
432 static $defaults = [
433 self::ATTR_DB_LEVEL_LOCKING => false,
434 self::ATTR_SCHEMAS_AS_TABLE_GROUPS => false
435 ];
436
437 $class = self::getClass( $dbType, $driver );
438
439 return call_user_func( [ $class, 'getAttributes' ] ) + $defaults;
440 }
441
442 /**
443 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
444 * @param string|null $driver Optional name of a specific DB client driver
445 * @return string Database subclass name to use
446 * @throws InvalidArgumentException
447 */
448 private static function getClass( $dbType, $driver = null ) {
449 // For database types with built-in support, the below maps type to IDatabase
450 // implementations. For types with multipe driver implementations (PHP extensions),
451 // an array can be used, keyed by extension name. In case of an array, the
452 // optional 'driver' parameter can be used to force a specific driver. Otherwise,
453 // we auto-detect the first available driver. For types without built-in support,
454 // an class named "Database<Type>" us used, eg. DatabaseFoo for type 'foo'.
455 static $builtinTypes = [
456 'mssql' => DatabaseMssql::class,
457 'mysql' => [ 'mysqli' => DatabaseMysqli::class ],
458 'sqlite' => DatabaseSqlite::class,
459 'postgres' => DatabasePostgres::class,
460 ];
461
462 $dbType = strtolower( $dbType );
463 $class = false;
464
465 if ( isset( $builtinTypes[$dbType] ) ) {
466 $possibleDrivers = $builtinTypes[$dbType];
467 if ( is_string( $possibleDrivers ) ) {
468 $class = $possibleDrivers;
469 } elseif ( (string)$driver !== '' ) {
470 if ( !isset( $possibleDrivers[$driver] ) ) {
471 throw new InvalidArgumentException( __METHOD__ .
472 " type '$dbType' does not support driver '{$driver}'" );
473 }
474
475 $class = $possibleDrivers[$driver];
476 } else {
477 foreach ( $possibleDrivers as $posDriver => $possibleClass ) {
478 if ( extension_loaded( $posDriver ) ) {
479 $class = $possibleClass;
480 break;
481 }
482 }
483 }
484 } else {
485 $class = 'Database' . ucfirst( $dbType );
486 }
487
488 if ( $class === false ) {
489 throw new InvalidArgumentException( __METHOD__ .
490 " no viable database extension found for type '$dbType'" );
491 }
492
493 return $class;
494 }
495
496 /**
497 * @return array Map of (Database::ATTR_* constant => value
498 * @since 1.31
499 */
500 protected static function getAttributes() {
501 return [];
502 }
503
504 /**
505 * Set the PSR-3 logger interface to use for query logging. (The logger
506 * interfaces for connection logging and error logging can be set with the
507 * constructor.)
508 *
509 * @param LoggerInterface $logger
510 */
511 public function setLogger( LoggerInterface $logger ) {
512 $this->queryLogger = $logger;
513 }
514
515 public function getServerInfo() {
516 return $this->getServerVersion();
517 }
518
519 public function bufferResults( $buffer = null ) {
520 $res = !$this->getFlag( self::DBO_NOBUFFER );
521 if ( $buffer !== null ) {
522 $buffer
523 ? $this->clearFlag( self::DBO_NOBUFFER )
524 : $this->setFlag( self::DBO_NOBUFFER );
525 }
526
527 return $res;
528 }
529
530 final public function trxLevel() {
531 return ( $this->trxShortId != '' ) ? 1 : 0;
532 }
533
534 public function trxTimestamp() {
535 return $this->trxLevel() ? $this->trxTimestamp : null;
536 }
537
538 /**
539 * @return int One of the STATUS_TRX_* class constants
540 * @since 1.31
541 */
542 public function trxStatus() {
543 return $this->trxStatus;
544 }
545
546 public function tablePrefix( $prefix = null ) {
547 $old = $this->currentDomain->getTablePrefix();
548 if ( $prefix !== null ) {
549 $this->currentDomain = new DatabaseDomain(
550 $this->currentDomain->getDatabase(),
551 $this->currentDomain->getSchema(),
552 $prefix
553 );
554 }
555
556 return $old;
557 }
558
559 public function dbSchema( $schema = null ) {
560 if ( strlen( $schema ) && $this->getDBname() === null ) {
561 throw new DBUnexpectedError( $this, "Cannot set schema to '$schema'; no database set" );
562 }
563
564 $old = $this->currentDomain->getSchema();
565 if ( $schema !== null ) {
566 $this->currentDomain = new DatabaseDomain(
567 $this->currentDomain->getDatabase(),
568 // DatabaseDomain uses null for unspecified schemas
569 strlen( $schema ) ? $schema : null,
570 $this->currentDomain->getTablePrefix()
571 );
572 }
573
574 return (string)$old;
575 }
576
577 /**
578 * @return string Schema to use to qualify relations in queries
579 */
580 protected function relationSchemaQualifier() {
581 return $this->dbSchema();
582 }
583
584 public function getLBInfo( $name = null ) {
585 if ( is_null( $name ) ) {
586 return $this->lbInfo;
587 }
588
589 if ( array_key_exists( $name, $this->lbInfo ) ) {
590 return $this->lbInfo[$name];
591 }
592
593 return null;
594 }
595
596 public function setLBInfo( $nameOrArray, $value = null ) {
597 if ( is_array( $nameOrArray ) ) {
598 $this->lbInfo = $nameOrArray;
599 } elseif ( is_string( $nameOrArray ) ) {
600 if ( $value !== null ) {
601 $this->lbInfo[$nameOrArray] = $value;
602 } else {
603 unset( $this->lbInfo[$nameOrArray] );
604 }
605 } else {
606 throw new InvalidArgumentException( "Got non-string key" );
607 }
608 }
609
610 public function setLazyMasterHandle( IDatabase $conn ) {
611 $this->lazyMasterHandle = $conn;
612 }
613
614 /**
615 * @return IDatabase|null
616 * @see setLazyMasterHandle()
617 * @since 1.27
618 */
619 protected function getLazyMasterHandle() {
620 return $this->lazyMasterHandle;
621 }
622
623 public function implicitOrderby() {
624 return true;
625 }
626
627 public function lastQuery() {
628 return $this->lastQuery;
629 }
630
631 public function lastDoneWrites() {
632 return $this->lastWriteTime ?: false;
633 }
634
635 public function writesPending() {
636 return $this->trxLevel() && $this->trxDoneWrites;
637 }
638
639 public function writesOrCallbacksPending() {
640 return $this->trxLevel() && (
641 $this->trxDoneWrites ||
642 $this->trxIdleCallbacks ||
643 $this->trxPreCommitCallbacks ||
644 $this->trxEndCallbacks ||
645 $this->trxSectionCancelCallbacks
646 );
647 }
648
649 public function preCommitCallbacksPending() {
650 return $this->trxLevel() && $this->trxPreCommitCallbacks;
651 }
652
653 /**
654 * @return string|null
655 */
656 final protected function getTransactionRoundId() {
657 // If transaction round participation is enabled, see if one is active
658 if ( $this->getFlag( self::DBO_TRX ) ) {
659 $id = $this->getLBInfo( 'trxRoundId' );
660
661 return is_string( $id ) ? $id : null;
662 }
663
664 return null;
665 }
666
667 public function pendingWriteQueryDuration( $type = self::ESTIMATE_TOTAL ) {
668 if ( !$this->trxLevel() ) {
669 return false;
670 } elseif ( !$this->trxDoneWrites ) {
671 return 0.0;
672 }
673
674 switch ( $type ) {
675 case self::ESTIMATE_DB_APPLY:
676 return $this->pingAndCalculateLastTrxApplyTime();
677 default: // everything
678 return $this->trxWriteDuration;
679 }
680 }
681
682 /**
683 * @return float Time to apply writes to replicas based on trxWrite* fields
684 */
685 private function pingAndCalculateLastTrxApplyTime() {
686 $this->ping( $rtt );
687
688 $rttAdjTotal = $this->trxWriteAdjQueryCount * $rtt;
689 $applyTime = max( $this->trxWriteAdjDuration - $rttAdjTotal, 0 );
690 // For omitted queries, make them count as something at least
691 $omitted = $this->trxWriteQueryCount - $this->trxWriteAdjQueryCount;
692 $applyTime += self::$TINY_WRITE_SEC * $omitted;
693
694 return $applyTime;
695 }
696
697 public function pendingWriteCallers() {
698 return $this->trxLevel() ? $this->trxWriteCallers : [];
699 }
700
701 public function pendingWriteRowsAffected() {
702 return $this->trxWriteAffectedRows;
703 }
704
705 /**
706 * List the methods that have write queries or callbacks for the current transaction
707 *
708 * This method should not be used outside of Database/LoadBalancer
709 *
710 * @return string[]
711 * @since 1.32
712 */
713 public function pendingWriteAndCallbackCallers() {
714 $fnames = $this->pendingWriteCallers();
715 foreach ( [
716 $this->trxIdleCallbacks,
717 $this->trxPreCommitCallbacks,
718 $this->trxEndCallbacks,
719 $this->trxSectionCancelCallbacks
720 ] as $callbacks ) {
721 foreach ( $callbacks as $callback ) {
722 $fnames[] = $callback[1];
723 }
724 }
725
726 return $fnames;
727 }
728
729 /**
730 * @return string
731 */
732 private function flatAtomicSectionList() {
733 return array_reduce( $this->trxAtomicLevels, function ( $accum, $v ) {
734 return $accum === null ? $v[0] : "$accum, " . $v[0];
735 } );
736 }
737
738 public function isOpen() {
739 return (bool)$this->conn;
740 }
741
742 public function setFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
743 if ( $flag & ~static::$DBO_MUTABLE ) {
744 throw new DBUnexpectedError(
745 $this,
746 "Got $flag (allowed: " . implode( ', ', static::$MUTABLE_FLAGS ) . ')'
747 );
748 }
749
750 if ( $remember === self::REMEMBER_PRIOR ) {
751 array_push( $this->priorFlags, $this->flags );
752 }
753
754 $this->flags |= $flag;
755 }
756
757 public function clearFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
758 if ( $flag & ~static::$DBO_MUTABLE ) {
759 throw new DBUnexpectedError(
760 $this,
761 "Got $flag (allowed: " . implode( ', ', static::$MUTABLE_FLAGS ) . ')'
762 );
763 }
764
765 if ( $remember === self::REMEMBER_PRIOR ) {
766 array_push( $this->priorFlags, $this->flags );
767 }
768
769 $this->flags &= ~$flag;
770 }
771
772 public function restoreFlags( $state = self::RESTORE_PRIOR ) {
773 if ( !$this->priorFlags ) {
774 return;
775 }
776
777 if ( $state === self::RESTORE_INITIAL ) {
778 $this->flags = reset( $this->priorFlags );
779 $this->priorFlags = [];
780 } else {
781 $this->flags = array_pop( $this->priorFlags );
782 }
783 }
784
785 public function getFlag( $flag ) {
786 return ( ( $this->flags & $flag ) === $flag );
787 }
788
789 public function getDomainID() {
790 return $this->currentDomain->getId();
791 }
792
793 /**
794 * Get information about an index into an object
795 * @param string $table Table name
796 * @param string $index Index name
797 * @param string $fname Calling function name
798 * @return mixed Database-specific index description class or false if the index does not exist
799 */
800 abstract function indexInfo( $table, $index, $fname = __METHOD__ );
801
802 /**
803 * Wrapper for addslashes()
804 *
805 * @param string $s String to be slashed.
806 * @return string Slashed string.
807 */
808 abstract function strencode( $s );
809
810 /**
811 * Set a custom error handler for logging errors during database connection
812 */
813 protected function installErrorHandler() {
814 $this->lastPhpError = false;
815 $this->htmlErrors = ini_set( 'html_errors', '0' );
816 set_error_handler( [ $this, 'connectionErrorLogger' ] );
817 }
818
819 /**
820 * Restore the previous error handler and return the last PHP error for this DB
821 *
822 * @return bool|string
823 */
824 protected function restoreErrorHandler() {
825 restore_error_handler();
826 if ( $this->htmlErrors !== false ) {
827 ini_set( 'html_errors', $this->htmlErrors );
828 }
829
830 return $this->getLastPHPError();
831 }
832
833 /**
834 * @return string|bool Last PHP error for this DB (typically connection errors)
835 */
836 protected function getLastPHPError() {
837 if ( $this->lastPhpError ) {
838 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->lastPhpError );
839 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
840
841 return $error;
842 }
843
844 return false;
845 }
846
847 /**
848 * Error handler for logging errors during database connection
849 * This method should not be used outside of Database classes
850 *
851 * @param int $errno
852 * @param string $errstr
853 */
854 public function connectionErrorLogger( $errno, $errstr ) {
855 $this->lastPhpError = $errstr;
856 }
857
858 /**
859 * Create a log context to pass to PSR-3 logger functions.
860 *
861 * @param array $extras Additional data to add to context
862 * @return array
863 */
864 protected function getLogContext( array $extras = [] ) {
865 return array_merge(
866 [
867 'db_server' => $this->server,
868 'db_name' => $this->getDBname(),
869 'db_user' => $this->user,
870 ],
871 $extras
872 );
873 }
874
875 final public function close() {
876 $exception = null; // error to throw after disconnecting
877
878 $wasOpen = (bool)$this->conn;
879 // This should mostly do nothing if the connection is already closed
880 if ( $this->conn ) {
881 // Roll back any dangling transaction first
882 if ( $this->trxLevel() ) {
883 if ( $this->trxAtomicLevels ) {
884 // Cannot let incomplete atomic sections be committed
885 $levels = $this->flatAtomicSectionList();
886 $exception = new DBUnexpectedError(
887 $this,
888 __METHOD__ . ": atomic sections $levels are still open"
889 );
890 } elseif ( $this->trxAutomatic ) {
891 // Only the connection manager can commit non-empty DBO_TRX transactions
892 // (empty ones we can silently roll back)
893 if ( $this->writesOrCallbacksPending() ) {
894 $exception = new DBUnexpectedError(
895 $this,
896 __METHOD__ .
897 ": mass commit/rollback of peer transaction required (DBO_TRX set)"
898 );
899 }
900 } else {
901 // Manual transactions should have been committed or rolled
902 // back, even if empty.
903 $exception = new DBUnexpectedError(
904 $this,
905 __METHOD__ . ": transaction is still open (from {$this->trxFname})"
906 );
907 }
908
909 if ( $this->trxEndCallbacksSuppressed ) {
910 $exception = $exception ?: new DBUnexpectedError(
911 $this,
912 __METHOD__ . ': callbacks are suppressed; cannot properly commit'
913 );
914 }
915
916 // Rollback the changes and run any callbacks as needed
917 $this->rollback( __METHOD__, self::FLUSHING_INTERNAL );
918 }
919
920 // Close the actual connection in the binding handle
921 $closed = $this->closeConnection();
922 } else {
923 $closed = true; // already closed; nothing to do
924 }
925
926 $this->conn = null;
927
928 // Throw any unexpected errors after having disconnected
929 if ( $exception instanceof Exception ) {
930 throw $exception;
931 }
932
933 // Note that various subclasses call close() at the start of open(), which itself is
934 // called by replaceLostConnection(). In that case, just because onTransactionResolution()
935 // callbacks are pending does not mean that an exception should be thrown. Rather, they
936 // will be executed after the reconnection step.
937 if ( $wasOpen ) {
938 // Sanity check that no callbacks are dangling
939 $fnames = $this->pendingWriteAndCallbackCallers();
940 if ( $fnames ) {
941 throw new RuntimeException(
942 "Transaction callbacks are still pending: " . implode( ', ', $fnames )
943 );
944 }
945 }
946
947 return $closed;
948 }
949
950 /**
951 * Make sure there is an open connection handle (alive or not) as a sanity check
952 *
953 * This guards against fatal errors to the binding handle not being defined
954 * in cases where open() was never called or close() was already called
955 *
956 * @throws DBUnexpectedError
957 */
958 final protected function assertHasConnectionHandle() {
959 if ( !$this->isOpen() ) {
960 throw new DBUnexpectedError( $this, "DB connection was already closed" );
961 }
962 }
963
964 /**
965 * Make sure that this server is not marked as a replica nor read-only as a sanity check
966 *
967 * @throws DBReadOnlyRoleError
968 * @throws DBReadOnlyError
969 */
970 protected function assertIsWritableMaster() {
971 if ( $this->getLBInfo( 'replica' ) === true ) {
972 throw new DBReadOnlyRoleError(
973 $this,
974 'Write operations are not allowed on replica database connections'
975 );
976 }
977 $reason = $this->getReadOnlyReason();
978 if ( $reason !== false ) {
979 throw new DBReadOnlyError( $this, "Database is read-only: $reason" );
980 }
981 }
982
983 /**
984 * Closes underlying database connection
985 * @since 1.20
986 * @return bool Whether connection was closed successfully
987 */
988 abstract protected function closeConnection();
989
990 /**
991 * Run a query and return a DBMS-dependent wrapper or boolean
992 *
993 * This is meant to handle the basic command of actually sending a query to the
994 * server via the driver. No implicit transaction, reconnection, nor retry logic
995 * should happen here. The higher level query() method is designed to handle those
996 * sorts of concerns. This method should not trigger such higher level methods.
997 *
998 * The lastError() and lastErrno() methods should meaningfully reflect what error,
999 * if any, occured during the last call to this method. Methods like executeQuery(),
1000 * query(), select(), insert(), update(), delete(), and upsert() implement their calls
1001 * to doQuery() such that an immediately subsequent call to lastError()/lastErrno()
1002 * meaningfully reflects any error that occured during that public query method call.
1003 *
1004 * For SELECT queries, this returns either:
1005 * - a) A driver-specific value/resource, only on success. This can be iterated
1006 * over by calling fetchObject()/fetchRow() until there are no more rows.
1007 * Alternatively, the result can be passed to resultObject() to obtain an
1008 * IResultWrapper instance which can then be iterated over via "foreach".
1009 * - b) False, on any query failure
1010 *
1011 * For non-SELECT queries, this returns either:
1012 * - a) A driver-specific value/resource, only on success
1013 * - b) True, only on success (e.g. no meaningful result other than "OK")
1014 * - c) False, on any query failure
1015 *
1016 * @param string $sql SQL query
1017 * @return mixed|bool An object, resource, or true on success; false on failure
1018 */
1019 abstract protected function doQuery( $sql );
1020
1021 /**
1022 * Determine whether a query writes to the DB. When in doubt, this returns true.
1023 *
1024 * Main use cases:
1025 *
1026 * - Subsequent web requests should not need to wait for replication from
1027 * the master position seen by this web request, unless this request made
1028 * changes to the master. This is handled by ChronologyProtector by checking
1029 * doneWrites() at the end of the request. doneWrites() returns true if any
1030 * query set lastWriteTime; which query() does based on isWriteQuery().
1031 *
1032 * - Reject write queries to replica DBs, in query().
1033 *
1034 * @param string $sql
1035 * @return bool
1036 */
1037 protected function isWriteQuery( $sql ) {
1038 // BEGIN and COMMIT queries are considered read queries here.
1039 // Database backends and drivers (MySQL, MariaDB, php-mysqli) generally
1040 // treat these as write queries, in that their results have "affected rows"
1041 // as meta data as from writes, instead of "num rows" as from reads.
1042 // But, we treat them as read queries because when reading data (from
1043 // either replica or master) we use transactions to enable repeatable-read
1044 // snapshots, which ensures we get consistent results from the same snapshot
1045 // for all queries within a request. Use cases:
1046 // - Treating these as writes would trigger ChronologyProtector (see method doc).
1047 // - We use this method to reject writes to replicas, but we need to allow
1048 // use of transactions on replicas for read snapshots. This is fine given
1049 // that transactions by themselves don't make changes, only actual writes
1050 // within the transaction matter, which we still detect.
1051 return !preg_match(
1052 '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SAVEPOINT|RELEASE|SET|SHOW|EXPLAIN|USE|\(SELECT)\b/i',
1053 $sql
1054 );
1055 }
1056
1057 /**
1058 * @param string $sql
1059 * @return string|null
1060 */
1061 protected function getQueryVerb( $sql ) {
1062 return preg_match( '/^\s*([a-z]+)/i', $sql, $m ) ? strtoupper( $m[1] ) : null;
1063 }
1064
1065 /**
1066 * Determine whether a SQL statement is sensitive to isolation level.
1067 *
1068 * A SQL statement is considered transactable if its result could vary
1069 * depending on the transaction isolation level. Operational commands
1070 * such as 'SET' and 'SHOW' are not considered to be transactable.
1071 *
1072 * Main purpose: Used by query() to decide whether to begin a transaction
1073 * before the current query (in DBO_TRX mode, on by default).
1074 *
1075 * @param string $sql
1076 * @return bool
1077 */
1078 protected function isTransactableQuery( $sql ) {
1079 return !in_array(
1080 $this->getQueryVerb( $sql ),
1081 [ 'BEGIN', 'ROLLBACK', 'COMMIT', 'SET', 'SHOW', 'CREATE', 'ALTER', 'USE', 'SHOW' ],
1082 true
1083 );
1084 }
1085
1086 /**
1087 * @param string $sql A SQL query
1088 * @param bool $pseudoPermanent Treat any table from CREATE TEMPORARY as pseudo-permanent
1089 * @return array A n-tuple of:
1090 * - int|null: A self::TEMP_* constant for temp table operations or null otherwise
1091 * - string|null: The name of the new temporary table $sql creates, or null
1092 * - string|null: The name of the temporary table that $sql drops, or null
1093 */
1094 protected function getTempWrites( $sql, $pseudoPermanent ) {
1095 static $qt = '[`"\']?(\w+)[`"\']?'; // quoted table
1096
1097 if ( preg_match(
1098 '/^CREATE\s+TEMPORARY\s+TABLE\s+(?:IF\s+NOT\s+EXISTS\s+)?' . $qt . '/i',
1099 $sql,
1100 $matches
1101 ) ) {
1102 $type = $pseudoPermanent ? self::$TEMP_PSEUDO_PERMANENT : self::$TEMP_NORMAL;
1103
1104 return [ $type, $matches[1], null ];
1105 } elseif ( preg_match(
1106 '/^DROP\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?' . $qt . '/i',
1107 $sql,
1108 $matches
1109 ) ) {
1110 return [ $this->sessionTempTables[$matches[1]] ?? null, null, $matches[1] ];
1111 } elseif ( preg_match(
1112 '/^TRUNCATE\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?' . $qt . '/i',
1113 $sql,
1114 $matches
1115 ) ) {
1116 return [ $this->sessionTempTables[$matches[1]] ?? null, null, null ];
1117 } elseif ( preg_match(
1118 '/^(?:(?:INSERT|REPLACE)\s+(?:\w+\s+)?INTO|UPDATE|DELETE\s+FROM)\s+' . $qt . '/i',
1119 $sql,
1120 $matches
1121 ) ) {
1122 return [ $this->sessionTempTables[$matches[1]] ?? null, null, null ];
1123 }
1124
1125 return [ null, null, null ];
1126 }
1127
1128 /**
1129 * @param IResultWrapper|bool $ret
1130 * @param int|null $tmpType TEMP_NORMAL or TEMP_PSEUDO_PERMANENT
1131 * @param string|null $tmpNew Name of created temp table
1132 * @param string|null $tmpDel Name of dropped temp table
1133 */
1134 protected function registerTempWrites( $ret, $tmpType, $tmpNew, $tmpDel ) {
1135 if ( $ret !== false ) {
1136 if ( $tmpNew !== null ) {
1137 $this->sessionTempTables[$tmpNew] = $tmpType;
1138 }
1139 if ( $tmpDel !== null ) {
1140 unset( $this->sessionTempTables[$tmpDel] );
1141 }
1142 }
1143 }
1144
1145 public function query( $sql, $fname = __METHOD__, $flags = 0 ) {
1146 $flags = (int)$flags; // b/c; this field used to be a bool
1147 // Sanity check that the SQL query is appropriate in the current context and is
1148 // allowed for an outside caller (e.g. does not break transaction/session tracking).
1149 $this->assertQueryIsCurrentlyAllowed( $sql, $fname );
1150
1151 // Send the query to the server and fetch any corresponding errors
1152 list( $ret, $err, $errno, $unignorable ) = $this->executeQuery( $sql, $fname, $flags );
1153 if ( $ret === false ) {
1154 $ignoreErrors = $this->hasFlags( $flags, self::QUERY_SILENCE_ERRORS );
1155 // Throw an error unless both the ignore flag was set and a rollback is not needed
1156 $this->reportQueryError( $err, $errno, $sql, $fname, $ignoreErrors && !$unignorable );
1157 }
1158
1159 return $this->resultObject( $ret );
1160 }
1161
1162 /**
1163 * Execute a query, retrying it if there is a recoverable connection loss
1164 *
1165 * This is similar to query() except:
1166 * - It does not prevent all non-ROLLBACK queries if there is a corrupted transaction
1167 * - It does not disallow raw queries that are supposed to use dedicated IDatabase methods
1168 * - It does not throw exceptions for common error cases
1169 *
1170 * This is meant for internal use with Database subclasses.
1171 *
1172 * @param string $sql Original SQL query
1173 * @param string $fname Name of the calling function
1174 * @param int $flags Bit field of class QUERY_* constants
1175 * @return array An n-tuple of:
1176 * - mixed|bool: An object, resource, or true on success; false on failure
1177 * - string: The result of calling lastError()
1178 * - int: The result of calling lastErrno()
1179 * - bool: Whether a rollback is needed to allow future non-rollback queries
1180 * @throws DBUnexpectedError
1181 */
1182 final protected function executeQuery( $sql, $fname, $flags ) {
1183 $this->assertHasConnectionHandle();
1184
1185 $priorTransaction = $this->trxLevel();
1186
1187 if ( $this->isWriteQuery( $sql ) ) {
1188 // In theory, non-persistent writes are allowed in read-only mode, but due to things
1189 // like https://bugs.mysql.com/bug.php?id=33669 that might not work anyway...
1190 $this->assertIsWritableMaster();
1191 // Do not treat temporary table writes as "meaningful writes" since they are only
1192 // visible to one session and are not permanent. Profile them as reads. Integration
1193 // tests can override this behavior via $flags.
1194 $pseudoPermanent = $this->hasFlags( $flags, self::QUERY_PSEUDO_PERMANENT );
1195 list( $tmpType, $tmpNew, $tmpDel ) = $this->getTempWrites( $sql, $pseudoPermanent );
1196 $isPermWrite = ( $tmpType !== self::$TEMP_NORMAL );
1197 // DBConnRef uses QUERY_REPLICA_ROLE to enforce the replica role for raw SQL queries
1198 if ( $isPermWrite && $this->hasFlags( $flags, self::QUERY_REPLICA_ROLE ) ) {
1199 throw new DBReadOnlyRoleError( $this, "Cannot write; target role is DB_REPLICA" );
1200 }
1201 } else {
1202 // No permanent writes in this query
1203 $isPermWrite = false;
1204 // No temporary tables written to either
1205 list( $tmpType, $tmpNew, $tmpDel ) = [ null, null, null ];
1206 }
1207
1208 // Add trace comment to the begin of the sql string, right after the operator.
1209 // Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (T44598)
1210 $commentedSql = preg_replace( '/\s|$/', " /* $fname {$this->agent} */ ", $sql, 1 );
1211
1212 // Send the query to the server and fetch any corresponding errors.
1213 // This also doubles as a "ping" to see if the connection was dropped.
1214 list( $ret, $err, $errno, $recoverableSR, $recoverableCL, $reconnected ) =
1215 $this->executeQueryAttempt( $sql, $commentedSql, $isPermWrite, $fname, $flags );
1216
1217 // Check if the query failed due to a recoverable connection loss
1218 $allowRetry = !$this->hasFlags( $flags, self::QUERY_NO_RETRY );
1219 if ( $ret === false && $recoverableCL && $reconnected && $allowRetry ) {
1220 // Silently resend the query to the server since it is safe and possible
1221 list( $ret, $err, $errno, $recoverableSR, $recoverableCL ) =
1222 $this->executeQueryAttempt( $sql, $commentedSql, $isPermWrite, $fname, $flags );
1223 }
1224
1225 // Register creation and dropping of temporary tables
1226 $this->registerTempWrites( $ret, $tmpType, $tmpNew, $tmpDel );
1227
1228 $corruptedTrx = false;
1229
1230 if ( $ret === false ) {
1231 if ( $priorTransaction ) {
1232 if ( $recoverableSR ) {
1233 # We're ignoring an error that caused just the current query to be aborted.
1234 # But log the cause so we can log a deprecation notice if a caller actually
1235 # does ignore it.
1236 $this->trxStatusIgnoredCause = [ $err, $errno, $fname ];
1237 } elseif ( !$recoverableCL ) {
1238 # Either the query was aborted or all queries after BEGIN where aborted.
1239 # In the first case, the only options going forward are (a) ROLLBACK, or
1240 # (b) ROLLBACK TO SAVEPOINT (if one was set). If the later case, the only
1241 # option is ROLLBACK, since the snapshots would have been released.
1242 $corruptedTrx = true; // cannot recover
1243 $this->trxStatus = self::STATUS_TRX_ERROR;
1244 $this->trxStatusCause =
1245 $this->getQueryExceptionAndLog( $err, $errno, $sql, $fname );
1246 $this->trxStatusIgnoredCause = null;
1247 }
1248 }
1249 }
1250
1251 return [ $ret, $err, $errno, $corruptedTrx ];
1252 }
1253
1254 /**
1255 * Wrapper for doQuery() that handles DBO_TRX, profiling, logging, affected row count
1256 * tracking, and reconnects (without retry) on query failure due to connection loss
1257 *
1258 * @param string $sql Original SQL query
1259 * @param string $commentedSql SQL query with debugging/trace comment
1260 * @param bool $isPermWrite Whether the query is a (non-temporary table) write
1261 * @param string $fname Name of the calling function
1262 * @param int $flags Bit field of class QUERY_* constants
1263 * @return array An n-tuple of:
1264 * - mixed|bool: An object, resource, or true on success; false on failure
1265 * - string: The result of calling lastError()
1266 * - int: The result of calling lastErrno()
1267 * - bool: Whether a statement rollback error occured
1268 * - bool: Whether a disconnect *both* happened *and* was recoverable
1269 * - bool: Whether a reconnection attempt was *both* made *and* succeeded
1270 * @throws DBUnexpectedError
1271 */
1272 private function executeQueryAttempt( $sql, $commentedSql, $isPermWrite, $fname, $flags ) {
1273 $priorWritesPending = $this->writesOrCallbacksPending();
1274
1275 if ( ( $flags & self::QUERY_IGNORE_DBO_TRX ) == 0 ) {
1276 $this->beginIfImplied( $sql, $fname );
1277 }
1278
1279 // Keep track of whether the transaction has write queries pending
1280 if ( $isPermWrite ) {
1281 $this->lastWriteTime = microtime( true );
1282 if ( $this->trxLevel() && !$this->trxDoneWrites ) {
1283 $this->trxDoneWrites = true;
1284 $this->trxProfiler->transactionWritingIn(
1285 $this->server, $this->getDomainID(), $this->trxShortId );
1286 }
1287 }
1288
1289 $prefix = !is_null( $this->getLBInfo( 'master' ) ) ? 'query-m: ' : 'query: ';
1290 $generalizedSql = new GeneralizedSql( $sql, $this->trxShortId, $prefix );
1291
1292 $startTime = microtime( true );
1293 $ps = $this->profiler
1294 ? ( $this->profiler )( $generalizedSql->stringify() )
1295 : null;
1296 $this->affectedRowCount = null;
1297 $this->lastQuery = $sql;
1298 $ret = $this->doQuery( $commentedSql );
1299 $lastError = $this->lastError();
1300 $lastErrno = $this->lastErrno();
1301
1302 $this->affectedRowCount = $this->affectedRows();
1303 unset( $ps ); // profile out (if set)
1304 $queryRuntime = max( microtime( true ) - $startTime, 0.0 );
1305
1306 $recoverableSR = false; // recoverable statement rollback?
1307 $recoverableCL = false; // recoverable connection loss?
1308 $reconnected = false; // reconnection both attempted and succeeded?
1309
1310 if ( $ret !== false ) {
1311 $this->lastPing = $startTime;
1312 if ( $isPermWrite && $this->trxLevel() ) {
1313 $this->updateTrxWriteQueryTime( $sql, $queryRuntime, $this->affectedRows() );
1314 $this->trxWriteCallers[] = $fname;
1315 }
1316 } elseif ( $this->wasConnectionError( $lastErrno ) ) {
1317 # Check if no meaningful session state was lost
1318 $recoverableCL = $this->canRecoverFromDisconnect( $sql, $priorWritesPending );
1319 # Update session state tracking and try to restore the connection
1320 $reconnected = $this->replaceLostConnection( __METHOD__ );
1321 } else {
1322 # Check if only the last query was rolled back
1323 $recoverableSR = $this->wasKnownStatementRollbackError();
1324 }
1325
1326 if ( $sql === self::$PING_QUERY ) {
1327 $this->lastRoundTripEstimate = $queryRuntime;
1328 }
1329
1330 $this->trxProfiler->recordQueryCompletion(
1331 $generalizedSql,
1332 $startTime,
1333 $isPermWrite,
1334 $isPermWrite ? $this->affectedRows() : $this->numRows( $ret )
1335 );
1336
1337 // Avoid the overhead of logging calls unless debug mode is enabled
1338 if ( $this->getFlag( self::DBO_DEBUG ) ) {
1339 $this->queryLogger->debug(
1340 "{method} [{runtime}s] {db_host}: $sql",
1341 [
1342 'method' => $fname,
1343 'db_host' => $this->getServer(),
1344 'domain' => $this->getDomainID(),
1345 'runtime' => round( $queryRuntime, 3 )
1346 ]
1347 );
1348 }
1349
1350 return [ $ret, $lastError, $lastErrno, $recoverableSR, $recoverableCL, $reconnected ];
1351 }
1352
1353 /**
1354 * Start an implicit transaction if DBO_TRX is enabled and no transaction is active
1355 *
1356 * @param string $sql
1357 * @param string $fname
1358 */
1359 private function beginIfImplied( $sql, $fname ) {
1360 if (
1361 !$this->trxLevel() &&
1362 $this->getFlag( self::DBO_TRX ) &&
1363 $this->isTransactableQuery( $sql )
1364 ) {
1365 $this->begin( __METHOD__ . " ($fname)", self::TRANSACTION_INTERNAL );
1366 $this->trxAutomatic = true;
1367 }
1368 }
1369
1370 /**
1371 * Update the estimated run-time of a query, not counting large row lock times
1372 *
1373 * LoadBalancer can be set to rollback transactions that will create huge replication
1374 * lag. It bases this estimate off of pendingWriteQueryDuration(). Certain simple
1375 * queries, like inserting a row can take a long time due to row locking. This method
1376 * uses some simple heuristics to discount those cases.
1377 *
1378 * @param string $sql A SQL write query
1379 * @param float $runtime Total runtime, including RTT
1380 * @param int $affected Affected row count
1381 */
1382 private function updateTrxWriteQueryTime( $sql, $runtime, $affected ) {
1383 // Whether this is indicative of replica DB runtime (except for RBR or ws_repl)
1384 $indicativeOfReplicaRuntime = true;
1385 if ( $runtime > self::$SLOW_WRITE_SEC ) {
1386 $verb = $this->getQueryVerb( $sql );
1387 // insert(), upsert(), replace() are fast unless bulky in size or blocked on locks
1388 if ( $verb === 'INSERT' ) {
1389 $indicativeOfReplicaRuntime = $this->affectedRows() > self::$SMALL_WRITE_ROWS;
1390 } elseif ( $verb === 'REPLACE' ) {
1391 $indicativeOfReplicaRuntime = $this->affectedRows() > self::$SMALL_WRITE_ROWS / 2;
1392 }
1393 }
1394
1395 $this->trxWriteDuration += $runtime;
1396 $this->trxWriteQueryCount += 1;
1397 $this->trxWriteAffectedRows += $affected;
1398 if ( $indicativeOfReplicaRuntime ) {
1399 $this->trxWriteAdjDuration += $runtime;
1400 $this->trxWriteAdjQueryCount += 1;
1401 }
1402 }
1403
1404 /**
1405 * Error out if the DB is not in a valid state for a query via query()
1406 *
1407 * @param string $sql
1408 * @param string $fname
1409 * @throws DBTransactionStateError
1410 */
1411 private function assertQueryIsCurrentlyAllowed( $sql, $fname ) {
1412 $verb = $this->getQueryVerb( $sql );
1413 if ( $verb === 'USE' ) {
1414 throw new DBUnexpectedError( $this, "Got USE query; use selectDomain() instead" );
1415 }
1416
1417 if ( $verb === 'ROLLBACK' ) { // transaction/savepoint
1418 return;
1419 }
1420
1421 if ( $this->trxStatus < self::STATUS_TRX_OK ) {
1422 throw new DBTransactionStateError(
1423 $this,
1424 "Cannot execute query from $fname while transaction status is ERROR",
1425 [],
1426 $this->trxStatusCause
1427 );
1428 } elseif ( $this->trxStatus === self::STATUS_TRX_OK && $this->trxStatusIgnoredCause ) {
1429 list( $iLastError, $iLastErrno, $iFname ) = $this->trxStatusIgnoredCause;
1430 call_user_func( $this->deprecationLogger,
1431 "Caller from $fname ignored an error originally raised from $iFname: " .
1432 "[$iLastErrno] $iLastError"
1433 );
1434 $this->trxStatusIgnoredCause = null;
1435 }
1436 }
1437
1438 public function assertNoOpenTransactions() {
1439 if ( $this->explicitTrxActive() ) {
1440 throw new DBTransactionError(
1441 $this,
1442 "Explicit transaction still active. A caller may have caught an error. "
1443 . "Open transactions: " . $this->flatAtomicSectionList()
1444 );
1445 }
1446 }
1447
1448 /**
1449 * Determine whether it is safe to retry queries after a database connection is lost
1450 *
1451 * @param string $sql SQL query
1452 * @param bool $priorWritesPending Whether there is a transaction open with
1453 * possible write queries or transaction pre-commit/idle callbacks
1454 * waiting on it to finish.
1455 * @return bool True if it is safe to retry the query, false otherwise
1456 */
1457 private function canRecoverFromDisconnect( $sql, $priorWritesPending ) {
1458 # Transaction dropped; this can mean lost writes, or REPEATABLE-READ snapshots.
1459 # Dropped connections also mean that named locks are automatically released.
1460 # Only allow error suppression in autocommit mode or when the lost transaction
1461 # didn't matter anyway (aside from DBO_TRX snapshot loss).
1462 if ( $this->sessionNamedLocks ) {
1463 return false; // possible critical section violation
1464 } elseif ( $this->sessionTempTables ) {
1465 return false; // tables might be queried latter
1466 } elseif ( $sql === 'COMMIT' ) {
1467 return !$priorWritesPending; // nothing written anyway? (T127428)
1468 } elseif ( $sql === 'ROLLBACK' ) {
1469 return true; // transaction lost...which is also what was requested :)
1470 } elseif ( $this->explicitTrxActive() ) {
1471 return false; // don't drop atomocity and explicit snapshots
1472 } elseif ( $priorWritesPending ) {
1473 return false; // prior writes lost from implicit transaction
1474 }
1475
1476 return true;
1477 }
1478
1479 /**
1480 * Clean things up after session (and thus transaction) loss before reconnect
1481 */
1482 private function handleSessionLossPreconnect() {
1483 // Clean up tracking of session-level things...
1484 // https://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html
1485 // https://www.postgresql.org/docs/9.2/static/sql-createtable.html (ignoring ON COMMIT)
1486 $this->sessionTempTables = [];
1487 // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1488 // https://www.postgresql.org/docs/9.4/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1489 $this->sessionNamedLocks = [];
1490 // Session loss implies transaction loss
1491 $oldTrxShortId = $this->consumeTrxShortId();
1492 $this->trxAtomicCounter = 0;
1493 $this->trxIdleCallbacks = []; // T67263; transaction already lost
1494 $this->trxPreCommitCallbacks = []; // T67263; transaction already lost
1495 // @note: leave trxRecurringCallbacks in place
1496 if ( $this->trxDoneWrites ) {
1497 $this->trxProfiler->transactionWritingOut(
1498 $this->server,
1499 $this->getDomainID(),
1500 $oldTrxShortId,
1501 $this->pendingWriteQueryDuration( self::ESTIMATE_TOTAL ),
1502 $this->trxWriteAffectedRows
1503 );
1504 }
1505 }
1506
1507 /**
1508 * Clean things up after session (and thus transaction) loss after reconnect
1509 */
1510 private function handleSessionLossPostconnect() {
1511 try {
1512 // Handle callbacks in trxEndCallbacks, e.g. onTransactionResolution().
1513 // If callback suppression is set then the array will remain unhandled.
1514 $this->runOnTransactionIdleCallbacks( self::TRIGGER_ROLLBACK );
1515 } catch ( Exception $ex ) {
1516 // Already logged; move on...
1517 }
1518 try {
1519 // Handle callbacks in trxRecurringCallbacks, e.g. setTransactionListener()
1520 $this->runTransactionListenerCallbacks( self::TRIGGER_ROLLBACK );
1521 } catch ( Exception $ex ) {
1522 // Already logged; move on...
1523 }
1524 }
1525
1526 /**
1527 * Reset the transaction ID and return the old one
1528 *
1529 * @return string The old transaction ID or the empty string if there wasn't one
1530 */
1531 private function consumeTrxShortId() {
1532 $old = $this->trxShortId;
1533 $this->trxShortId = '';
1534
1535 return $old;
1536 }
1537
1538 /**
1539 * Checks whether the cause of the error is detected to be a timeout.
1540 *
1541 * It returns false by default, and not all engines support detecting this yet.
1542 * If this returns false, it will be treated as a generic query error.
1543 *
1544 * @param string $error Error text
1545 * @param int $errno Error number
1546 * @return bool
1547 */
1548 protected function wasQueryTimeout( $error, $errno ) {
1549 return false;
1550 }
1551
1552 /**
1553 * Report a query error. Log the error, and if neither the object ignore
1554 * flag nor the $ignoreErrors flag is set, throw a DBQueryError.
1555 *
1556 * @param string $error
1557 * @param int $errno
1558 * @param string $sql
1559 * @param string $fname
1560 * @param bool $ignore
1561 * @throws DBQueryError
1562 */
1563 public function reportQueryError( $error, $errno, $sql, $fname, $ignore = false ) {
1564 if ( $ignore ) {
1565 $this->queryLogger->debug( "SQL ERROR (ignored): $error" );
1566 } else {
1567 throw $this->getQueryExceptionAndLog( $error, $errno, $sql, $fname );
1568 }
1569 }
1570
1571 /**
1572 * @param string $error
1573 * @param string|int $errno
1574 * @param string $sql
1575 * @param string $fname
1576 * @return DBError
1577 */
1578 private function getQueryExceptionAndLog( $error, $errno, $sql, $fname ) {
1579 $this->queryLogger->error(
1580 "{fname}\t{db_server}\t{errno}\t{error}\t{sql1line}",
1581 $this->getLogContext( [
1582 'method' => __METHOD__,
1583 'errno' => $errno,
1584 'error' => $error,
1585 'sql1line' => mb_substr( str_replace( "\n", "\\n", $sql ), 0, 5 * 1024 ),
1586 'fname' => $fname,
1587 'trace' => ( new RuntimeException() )->getTraceAsString()
1588 ] )
1589 );
1590
1591 if ( $this->wasQueryTimeout( $error, $errno ) ) {
1592 $e = new DBQueryTimeoutError( $this, $error, $errno, $sql, $fname );
1593 } elseif ( $this->wasConnectionError( $errno ) ) {
1594 $e = new DBQueryDisconnectedError( $this, $error, $errno, $sql, $fname );
1595 } else {
1596 $e = new DBQueryError( $this, $error, $errno, $sql, $fname );
1597 }
1598
1599 return $e;
1600 }
1601
1602 /**
1603 * @param string $error
1604 * @return DBConnectionError
1605 */
1606 final protected function newExceptionAfterConnectError( $error ) {
1607 // Connection was not fully initialized and is not safe for use
1608 $this->conn = null;
1609
1610 $this->connLogger->error(
1611 "Error connecting to {db_server} as user {db_user}: {error}",
1612 $this->getLogContext( [
1613 'error' => $error,
1614 'trace' => ( new RuntimeException() )->getTraceAsString()
1615 ] )
1616 );
1617
1618 return new DBConnectionError( $this, $error );
1619 }
1620
1621 public function freeResult( $res ) {
1622 }
1623
1624 public function selectField(
1625 $table, $var, $cond = '', $fname = __METHOD__, $options = [], $join_conds = []
1626 ) {
1627 if ( $var === '*' ) { // sanity
1628 throw new DBUnexpectedError( $this, "Cannot use a * field: got '$var'" );
1629 }
1630
1631 if ( !is_array( $options ) ) {
1632 $options = [ $options ];
1633 }
1634
1635 $options['LIMIT'] = 1;
1636
1637 $res = $this->select( $table, $var, $cond, $fname, $options, $join_conds );
1638 if ( $res === false ) {
1639 throw new DBUnexpectedError( $this, "Got false from select()" );
1640 }
1641
1642 $row = $this->fetchRow( $res );
1643 if ( $row === false ) {
1644 return false;
1645 }
1646
1647 return reset( $row );
1648 }
1649
1650 public function selectFieldValues(
1651 $table, $var, $cond = '', $fname = __METHOD__, $options = [], $join_conds = []
1652 ) {
1653 if ( $var === '*' ) { // sanity
1654 throw new DBUnexpectedError( $this, "Cannot use a * field" );
1655 } elseif ( !is_string( $var ) ) { // sanity
1656 throw new DBUnexpectedError( $this, "Cannot use an array of fields" );
1657 }
1658
1659 if ( !is_array( $options ) ) {
1660 $options = [ $options ];
1661 }
1662
1663 $res = $this->select( $table, [ 'value' => $var ], $cond, $fname, $options, $join_conds );
1664 if ( $res === false ) {
1665 throw new DBUnexpectedError( $this, "Got false from select()" );
1666 }
1667
1668 $values = [];
1669 foreach ( $res as $row ) {
1670 $values[] = $row->value;
1671 }
1672
1673 return $values;
1674 }
1675
1676 /**
1677 * Returns an optional USE INDEX clause to go after the table, and a
1678 * string to go at the end of the query.
1679 *
1680 * @param array $options Associative array of options to be turned into
1681 * an SQL query, valid keys are listed in the function.
1682 * @return array
1683 * @see Database::select()
1684 */
1685 protected function makeSelectOptions( $options ) {
1686 $preLimitTail = $postLimitTail = '';
1687 $startOpts = '';
1688
1689 $noKeyOptions = [];
1690
1691 foreach ( $options as $key => $option ) {
1692 if ( is_numeric( $key ) ) {
1693 $noKeyOptions[$option] = true;
1694 }
1695 }
1696
1697 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1698
1699 $preLimitTail .= $this->makeOrderBy( $options );
1700
1701 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1702 $postLimitTail .= ' FOR UPDATE';
1703 }
1704
1705 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1706 $postLimitTail .= ' LOCK IN SHARE MODE';
1707 }
1708
1709 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1710 $startOpts .= 'DISTINCT';
1711 }
1712
1713 # Various MySQL extensions
1714 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1715 $startOpts .= ' /*! STRAIGHT_JOIN */';
1716 }
1717
1718 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1719 $startOpts .= ' SQL_BIG_RESULT';
1720 }
1721
1722 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1723 $startOpts .= ' SQL_BUFFER_RESULT';
1724 }
1725
1726 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1727 $startOpts .= ' SQL_SMALL_RESULT';
1728 }
1729
1730 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1731 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1732 }
1733
1734 if ( isset( $options['USE INDEX'] ) && is_string( $options['USE INDEX'] ) ) {
1735 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1736 } else {
1737 $useIndex = '';
1738 }
1739 if ( isset( $options['IGNORE INDEX'] ) && is_string( $options['IGNORE INDEX'] ) ) {
1740 $ignoreIndex = $this->ignoreIndexClause( $options['IGNORE INDEX'] );
1741 } else {
1742 $ignoreIndex = '';
1743 }
1744
1745 return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ];
1746 }
1747
1748 /**
1749 * Returns an optional GROUP BY with an optional HAVING
1750 *
1751 * @param array $options Associative array of options
1752 * @return string
1753 * @see Database::select()
1754 * @since 1.21
1755 */
1756 protected function makeGroupByWithHaving( $options ) {
1757 $sql = '';
1758 if ( isset( $options['GROUP BY'] ) ) {
1759 $gb = is_array( $options['GROUP BY'] )
1760 ? implode( ',', $options['GROUP BY'] )
1761 : $options['GROUP BY'];
1762 $sql .= ' GROUP BY ' . $gb;
1763 }
1764 if ( isset( $options['HAVING'] ) ) {
1765 $having = is_array( $options['HAVING'] )
1766 ? $this->makeList( $options['HAVING'], self::LIST_AND )
1767 : $options['HAVING'];
1768 $sql .= ' HAVING ' . $having;
1769 }
1770
1771 return $sql;
1772 }
1773
1774 /**
1775 * Returns an optional ORDER BY
1776 *
1777 * @param array $options Associative array of options
1778 * @return string
1779 * @see Database::select()
1780 * @since 1.21
1781 */
1782 protected function makeOrderBy( $options ) {
1783 if ( isset( $options['ORDER BY'] ) ) {
1784 $ob = is_array( $options['ORDER BY'] )
1785 ? implode( ',', $options['ORDER BY'] )
1786 : $options['ORDER BY'];
1787
1788 return ' ORDER BY ' . $ob;
1789 }
1790
1791 return '';
1792 }
1793
1794 public function select(
1795 $table, $vars, $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
1796 ) {
1797 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1798
1799 return $this->query( $sql, $fname );
1800 }
1801
1802 public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__,
1803 $options = [], $join_conds = []
1804 ) {
1805 if ( is_array( $vars ) ) {
1806 $fields = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1807 } else {
1808 $fields = $vars;
1809 }
1810
1811 $options = (array)$options;
1812 $useIndexes = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1813 ? $options['USE INDEX']
1814 : [];
1815 $ignoreIndexes = (
1816 isset( $options['IGNORE INDEX'] ) &&
1817 is_array( $options['IGNORE INDEX'] )
1818 )
1819 ? $options['IGNORE INDEX']
1820 : [];
1821
1822 if (
1823 $this->selectOptionsIncludeLocking( $options ) &&
1824 $this->selectFieldsOrOptionsAggregate( $vars, $options )
1825 ) {
1826 // Some DB types (postgres/oracle) disallow FOR UPDATE with aggregate
1827 // functions. Discourage use of such queries to encourage compatibility.
1828 call_user_func(
1829 $this->deprecationLogger,
1830 __METHOD__ . ": aggregation used with a locking SELECT ($fname)"
1831 );
1832 }
1833
1834 if ( is_array( $table ) ) {
1835 $from = ' FROM ' .
1836 $this->tableNamesWithIndexClauseOrJOIN(
1837 $table, $useIndexes, $ignoreIndexes, $join_conds );
1838 } elseif ( $table != '' ) {
1839 $from = ' FROM ' .
1840 $this->tableNamesWithIndexClauseOrJOIN(
1841 [ $table ], $useIndexes, $ignoreIndexes, [] );
1842 } else {
1843 $from = '';
1844 }
1845
1846 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ) =
1847 $this->makeSelectOptions( $options );
1848
1849 if ( is_array( $conds ) ) {
1850 $conds = $this->makeList( $conds, self::LIST_AND );
1851 }
1852
1853 if ( $conds === null || $conds === false ) {
1854 $this->queryLogger->warning(
1855 __METHOD__
1856 . ' called from '
1857 . $fname
1858 . ' with incorrect parameters: $conds must be a string or an array'
1859 );
1860 $conds = '';
1861 }
1862
1863 if ( $conds === '' || $conds === '*' ) {
1864 $sql = "SELECT $startOpts $fields $from $useIndex $ignoreIndex $preLimitTail";
1865 } elseif ( is_string( $conds ) ) {
1866 $sql = "SELECT $startOpts $fields $from $useIndex $ignoreIndex " .
1867 "WHERE $conds $preLimitTail";
1868 } else {
1869 throw new DBUnexpectedError( $this, __METHOD__ . ' called with incorrect parameters' );
1870 }
1871
1872 if ( isset( $options['LIMIT'] ) ) {
1873 $sql = $this->limitResult( $sql, $options['LIMIT'],
1874 $options['OFFSET'] ?? false );
1875 }
1876 $sql = "$sql $postLimitTail";
1877
1878 if ( isset( $options['EXPLAIN'] ) ) {
1879 $sql = 'EXPLAIN ' . $sql;
1880 }
1881
1882 return $sql;
1883 }
1884
1885 public function selectRow( $table, $vars, $conds, $fname = __METHOD__,
1886 $options = [], $join_conds = []
1887 ) {
1888 $options = (array)$options;
1889 $options['LIMIT'] = 1;
1890
1891 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1892 if ( $res === false ) {
1893 throw new DBUnexpectedError( $this, "Got false from select()" );
1894 }
1895
1896 if ( !$this->numRows( $res ) ) {
1897 return false;
1898 }
1899
1900 return $this->fetchObject( $res );
1901 }
1902
1903 public function estimateRowCount(
1904 $table, $var = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
1905 ) {
1906 $conds = $this->normalizeConditions( $conds, $fname );
1907 $column = $this->extractSingleFieldFromList( $var );
1908 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1909 $conds[] = "$column IS NOT NULL";
1910 }
1911
1912 $res = $this->select(
1913 $table, [ 'rowcount' => 'COUNT(*)' ], $conds, $fname, $options, $join_conds
1914 );
1915 $row = $res ? $this->fetchRow( $res ) : [];
1916
1917 return isset( $row['rowcount'] ) ? (int)$row['rowcount'] : 0;
1918 }
1919
1920 public function selectRowCount(
1921 $tables, $var = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
1922 ) {
1923 $conds = $this->normalizeConditions( $conds, $fname );
1924 $column = $this->extractSingleFieldFromList( $var );
1925 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1926 $conds[] = "$column IS NOT NULL";
1927 }
1928
1929 $res = $this->select(
1930 [
1931 'tmp_count' => $this->buildSelectSubquery(
1932 $tables,
1933 '1',
1934 $conds,
1935 $fname,
1936 $options,
1937 $join_conds
1938 )
1939 ],
1940 [ 'rowcount' => 'COUNT(*)' ],
1941 [],
1942 $fname
1943 );
1944 $row = $res ? $this->fetchRow( $res ) : [];
1945
1946 return isset( $row['rowcount'] ) ? (int)$row['rowcount'] : 0;
1947 }
1948
1949 /**
1950 * @param string|array $options
1951 * @return bool
1952 */
1953 private function selectOptionsIncludeLocking( $options ) {
1954 $options = (array)$options;
1955 foreach ( [ 'FOR UPDATE', 'LOCK IN SHARE MODE' ] as $lock ) {
1956 if ( in_array( $lock, $options, true ) ) {
1957 return true;
1958 }
1959 }
1960
1961 return false;
1962 }
1963
1964 /**
1965 * @param array|string $fields
1966 * @param array|string $options
1967 * @return bool
1968 */
1969 private function selectFieldsOrOptionsAggregate( $fields, $options ) {
1970 foreach ( (array)$options as $key => $value ) {
1971 if ( is_string( $key ) ) {
1972 if ( preg_match( '/^(?:GROUP BY|HAVING)$/i', $key ) ) {
1973 return true;
1974 }
1975 } elseif ( is_string( $value ) ) {
1976 if ( preg_match( '/^(?:DISTINCT|DISTINCTROW)$/i', $value ) ) {
1977 return true;
1978 }
1979 }
1980 }
1981
1982 $regex = '/^(?:COUNT|MIN|MAX|SUM|GROUP_CONCAT|LISTAGG|ARRAY_AGG)\s*\\(/i';
1983 foreach ( (array)$fields as $field ) {
1984 if ( is_string( $field ) && preg_match( $regex, $field ) ) {
1985 return true;
1986 }
1987 }
1988
1989 return false;
1990 }
1991
1992 /**
1993 * @param array|string $conds
1994 * @param string $fname
1995 * @return array
1996 */
1997 final protected function normalizeConditions( $conds, $fname ) {
1998 if ( $conds === null || $conds === false ) {
1999 $this->queryLogger->warning(
2000 __METHOD__
2001 . ' called from '
2002 . $fname
2003 . ' with incorrect parameters: $conds must be a string or an array'
2004 );
2005 $conds = '';
2006 }
2007
2008 if ( !is_array( $conds ) ) {
2009 $conds = ( $conds === '' ) ? [] : [ $conds ];
2010 }
2011
2012 return $conds;
2013 }
2014
2015 /**
2016 * @param array|string $var Field parameter in the style of select()
2017 * @return string|null Column name or null; ignores aliases
2018 * @throws DBUnexpectedError Errors out if multiple columns are given
2019 */
2020 final protected function extractSingleFieldFromList( $var ) {
2021 if ( is_array( $var ) ) {
2022 if ( !$var ) {
2023 $column = null;
2024 } elseif ( count( $var ) == 1 ) {
2025 $column = $var[0] ?? reset( $var );
2026 } else {
2027 throw new DBUnexpectedError( $this, __METHOD__ . ': got multiple columns' );
2028 }
2029 } else {
2030 $column = $var;
2031 }
2032
2033 return $column;
2034 }
2035
2036 public function lockForUpdate(
2037 $table, $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
2038 ) {
2039 if ( !$this->trxLevel() && !$this->getFlag( self::DBO_TRX ) ) {
2040 throw new DBUnexpectedError(
2041 $this,
2042 __METHOD__ . ': no transaction is active nor is DBO_TRX set'
2043 );
2044 }
2045
2046 $options = (array)$options;
2047 $options[] = 'FOR UPDATE';
2048
2049 return $this->selectRowCount( $table, '*', $conds, $fname, $options, $join_conds );
2050 }
2051
2052 public function fieldExists( $table, $field, $fname = __METHOD__ ) {
2053 $info = $this->fieldInfo( $table, $field );
2054
2055 return (bool)$info;
2056 }
2057
2058 public function indexExists( $table, $index, $fname = __METHOD__ ) {
2059 if ( !$this->tableExists( $table ) ) {
2060 return null;
2061 }
2062
2063 $info = $this->indexInfo( $table, $index, $fname );
2064 if ( is_null( $info ) ) {
2065 return null;
2066 } else {
2067 return $info !== false;
2068 }
2069 }
2070
2071 abstract public function tableExists( $table, $fname = __METHOD__ );
2072
2073 public function indexUnique( $table, $index ) {
2074 $indexInfo = $this->indexInfo( $table, $index );
2075
2076 if ( !$indexInfo ) {
2077 return null;
2078 }
2079
2080 return !$indexInfo[0]->Non_unique;
2081 }
2082
2083 /**
2084 * Helper for Database::insert().
2085 *
2086 * @param array $options
2087 * @return string
2088 */
2089 protected function makeInsertOptions( $options ) {
2090 return implode( ' ', $options );
2091 }
2092
2093 public function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
2094 # No rows to insert, easy just return now
2095 if ( !count( $a ) ) {
2096 return true;
2097 }
2098
2099 $table = $this->tableName( $table );
2100
2101 if ( !is_array( $options ) ) {
2102 $options = [ $options ];
2103 }
2104
2105 $options = $this->makeInsertOptions( $options );
2106
2107 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
2108 $multi = true;
2109 $keys = array_keys( $a[0] );
2110 } else {
2111 $multi = false;
2112 $keys = array_keys( $a );
2113 }
2114
2115 $sql = 'INSERT ' . $options .
2116 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
2117
2118 if ( $multi ) {
2119 $first = true;
2120 foreach ( $a as $row ) {
2121 if ( $first ) {
2122 $first = false;
2123 } else {
2124 $sql .= ',';
2125 }
2126 $sql .= '(' . $this->makeList( $row ) . ')';
2127 }
2128 } else {
2129 $sql .= '(' . $this->makeList( $a ) . ')';
2130 }
2131
2132 $this->query( $sql, $fname );
2133
2134 return true;
2135 }
2136
2137 /**
2138 * Make UPDATE options array for Database::makeUpdateOptions
2139 *
2140 * @param array $options
2141 * @return array
2142 */
2143 protected function makeUpdateOptionsArray( $options ) {
2144 if ( !is_array( $options ) ) {
2145 $options = [ $options ];
2146 }
2147
2148 $opts = [];
2149
2150 if ( in_array( 'IGNORE', $options ) ) {
2151 $opts[] = 'IGNORE';
2152 }
2153
2154 return $opts;
2155 }
2156
2157 /**
2158 * Make UPDATE options for the Database::update function
2159 *
2160 * @param array $options The options passed to Database::update
2161 * @return string
2162 */
2163 protected function makeUpdateOptions( $options ) {
2164 $opts = $this->makeUpdateOptionsArray( $options );
2165
2166 return implode( ' ', $opts );
2167 }
2168
2169 public function update( $table, $values, $conds, $fname = __METHOD__, $options = [] ) {
2170 $table = $this->tableName( $table );
2171 $opts = $this->makeUpdateOptions( $options );
2172 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, self::LIST_SET );
2173
2174 if ( $conds !== [] && $conds !== '*' ) {
2175 $sql .= " WHERE " . $this->makeList( $conds, self::LIST_AND );
2176 }
2177
2178 $this->query( $sql, $fname );
2179
2180 return true;
2181 }
2182
2183 public function makeList( $a, $mode = self::LIST_COMMA ) {
2184 if ( !is_array( $a ) ) {
2185 throw new DBUnexpectedError( $this, __METHOD__ . ' called with incorrect parameters' );
2186 }
2187
2188 $first = true;
2189 $list = '';
2190
2191 foreach ( $a as $field => $value ) {
2192 if ( !$first ) {
2193 if ( $mode == self::LIST_AND ) {
2194 $list .= ' AND ';
2195 } elseif ( $mode == self::LIST_OR ) {
2196 $list .= ' OR ';
2197 } else {
2198 $list .= ',';
2199 }
2200 } else {
2201 $first = false;
2202 }
2203
2204 if ( ( $mode == self::LIST_AND || $mode == self::LIST_OR ) && is_numeric( $field ) ) {
2205 $list .= "($value)";
2206 } elseif ( $mode == self::LIST_SET && is_numeric( $field ) ) {
2207 $list .= "$value";
2208 } elseif (
2209 ( $mode == self::LIST_AND || $mode == self::LIST_OR ) && is_array( $value )
2210 ) {
2211 // Remove null from array to be handled separately if found
2212 $includeNull = false;
2213 foreach ( array_keys( $value, null, true ) as $nullKey ) {
2214 $includeNull = true;
2215 unset( $value[$nullKey] );
2216 }
2217 if ( count( $value ) == 0 && !$includeNull ) {
2218 throw new InvalidArgumentException(
2219 __METHOD__ . ": empty input for field $field" );
2220 } elseif ( count( $value ) == 0 ) {
2221 // only check if $field is null
2222 $list .= "$field IS NULL";
2223 } else {
2224 // IN clause contains at least one valid element
2225 if ( $includeNull ) {
2226 // Group subconditions to ensure correct precedence
2227 $list .= '(';
2228 }
2229 if ( count( $value ) == 1 ) {
2230 // Special-case single values, as IN isn't terribly efficient
2231 // Don't necessarily assume the single key is 0; we don't
2232 // enforce linear numeric ordering on other arrays here.
2233 $value = array_values( $value )[0];
2234 $list .= $field . " = " . $this->addQuotes( $value );
2235 } else {
2236 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
2237 }
2238 // if null present in array, append IS NULL
2239 if ( $includeNull ) {
2240 $list .= " OR $field IS NULL)";
2241 }
2242 }
2243 } elseif ( $value === null ) {
2244 if ( $mode == self::LIST_AND || $mode == self::LIST_OR ) {
2245 $list .= "$field IS ";
2246 } elseif ( $mode == self::LIST_SET ) {
2247 $list .= "$field = ";
2248 }
2249 $list .= 'NULL';
2250 } else {
2251 if (
2252 $mode == self::LIST_AND || $mode == self::LIST_OR || $mode == self::LIST_SET
2253 ) {
2254 $list .= "$field = ";
2255 }
2256 $list .= $mode == self::LIST_NAMES ? $value : $this->addQuotes( $value );
2257 }
2258 }
2259
2260 return $list;
2261 }
2262
2263 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
2264 $conds = [];
2265
2266 foreach ( $data as $base => $sub ) {
2267 if ( count( $sub ) ) {
2268 $conds[] = $this->makeList(
2269 [ $baseKey => $base, $subKey => array_keys( $sub ) ],
2270 self::LIST_AND );
2271 }
2272 }
2273
2274 if ( $conds ) {
2275 return $this->makeList( $conds, self::LIST_OR );
2276 } else {
2277 // Nothing to search for...
2278 return false;
2279 }
2280 }
2281
2282 public function aggregateValue( $valuedata, $valuename = 'value' ) {
2283 return $valuename;
2284 }
2285
2286 public function bitNot( $field ) {
2287 return "(~$field)";
2288 }
2289
2290 public function bitAnd( $fieldLeft, $fieldRight ) {
2291 return "($fieldLeft & $fieldRight)";
2292 }
2293
2294 public function bitOr( $fieldLeft, $fieldRight ) {
2295 return "($fieldLeft | $fieldRight)";
2296 }
2297
2298 public function buildConcat( $stringList ) {
2299 return 'CONCAT(' . implode( ',', $stringList ) . ')';
2300 }
2301
2302 public function buildGroupConcatField(
2303 $delim, $table, $field, $conds = '', $join_conds = []
2304 ) {
2305 $fld = "GROUP_CONCAT($field SEPARATOR " . $this->addQuotes( $delim ) . ')';
2306
2307 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
2308 }
2309
2310 public function buildSubstring( $input, $startPosition, $length = null ) {
2311 $this->assertBuildSubstringParams( $startPosition, $length );
2312 $functionBody = "$input FROM $startPosition";
2313 if ( $length !== null ) {
2314 $functionBody .= " FOR $length";
2315 }
2316 return 'SUBSTRING(' . $functionBody . ')';
2317 }
2318
2319 /**
2320 * Check type and bounds for parameters to self::buildSubstring()
2321 *
2322 * All supported databases have substring functions that behave the same for
2323 * positive $startPosition and non-negative $length, but behaviors differ when
2324 * given 0 or negative $startPosition or negative $length. The simplest
2325 * solution to that is to just forbid those values.
2326 *
2327 * @param int $startPosition
2328 * @param int|null $length
2329 * @since 1.31
2330 */
2331 protected function assertBuildSubstringParams( $startPosition, $length ) {
2332 if ( !is_int( $startPosition ) || $startPosition <= 0 ) {
2333 throw new InvalidArgumentException(
2334 '$startPosition must be a positive integer'
2335 );
2336 }
2337 if ( !( is_int( $length ) && $length >= 0 || $length === null ) ) {
2338 throw new InvalidArgumentException(
2339 '$length must be null or an integer greater than or equal to 0'
2340 );
2341 }
2342 }
2343
2344 public function buildStringCast( $field ) {
2345 // In theory this should work for any standards-compliant
2346 // SQL implementation, although it may not be the best way to do it.
2347 return "CAST( $field AS CHARACTER )";
2348 }
2349
2350 public function buildIntegerCast( $field ) {
2351 return 'CAST( ' . $field . ' AS INTEGER )';
2352 }
2353
2354 public function buildSelectSubquery(
2355 $table, $vars, $conds = '', $fname = __METHOD__,
2356 $options = [], $join_conds = []
2357 ) {
2358 return new Subquery(
2359 $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds )
2360 );
2361 }
2362
2363 public function databasesAreIndependent() {
2364 return false;
2365 }
2366
2367 final public function selectDB( $db ) {
2368 $this->selectDomain( new DatabaseDomain(
2369 $db,
2370 $this->currentDomain->getSchema(),
2371 $this->currentDomain->getTablePrefix()
2372 ) );
2373
2374 return true;
2375 }
2376
2377 final public function selectDomain( $domain ) {
2378 $this->doSelectDomain( DatabaseDomain::newFromId( $domain ) );
2379 }
2380
2381 /**
2382 * @param DatabaseDomain $domain
2383 * @throws DBConnectionError
2384 * @throws DBError
2385 * @since 1.32
2386 */
2387 protected function doSelectDomain( DatabaseDomain $domain ) {
2388 $this->currentDomain = $domain;
2389 }
2390
2391 public function getDBname() {
2392 return $this->currentDomain->getDatabase();
2393 }
2394
2395 public function getServer() {
2396 return $this->server;
2397 }
2398
2399 public function tableName( $name, $format = 'quoted' ) {
2400 if ( $name instanceof Subquery ) {
2401 throw new DBUnexpectedError(
2402 $this,
2403 __METHOD__ . ': got Subquery instance when expecting a string'
2404 );
2405 }
2406
2407 # Skip the entire process when we have a string quoted on both ends.
2408 # Note that we check the end so that we will still quote any use of
2409 # use of `database`.table. But won't break things if someone wants
2410 # to query a database table with a dot in the name.
2411 if ( $this->isQuotedIdentifier( $name ) ) {
2412 return $name;
2413 }
2414
2415 # Lets test for any bits of text that should never show up in a table
2416 # name. Basically anything like JOIN or ON which are actually part of
2417 # SQL queries, but may end up inside of the table value to combine
2418 # sql. Such as how the API is doing.
2419 # Note that we use a whitespace test rather than a \b test to avoid
2420 # any remote case where a word like on may be inside of a table name
2421 # surrounded by symbols which may be considered word breaks.
2422 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2423 $this->queryLogger->warning(
2424 __METHOD__ . ": use of subqueries is not supported this way",
2425 [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
2426 );
2427
2428 return $name;
2429 }
2430
2431 # Split database and table into proper variables.
2432 list( $database, $schema, $prefix, $table ) = $this->qualifiedTableComponents( $name );
2433
2434 # Quote $table and apply the prefix if not quoted.
2435 # $tableName might be empty if this is called from Database::replaceVars()
2436 $tableName = "{$prefix}{$table}";
2437 if ( $format === 'quoted'
2438 && !$this->isQuotedIdentifier( $tableName )
2439 && $tableName !== ''
2440 ) {
2441 $tableName = $this->addIdentifierQuotes( $tableName );
2442 }
2443
2444 # Quote $schema and $database and merge them with the table name if needed
2445 $tableName = $this->prependDatabaseOrSchema( $schema, $tableName, $format );
2446 $tableName = $this->prependDatabaseOrSchema( $database, $tableName, $format );
2447
2448 return $tableName;
2449 }
2450
2451 /**
2452 * Get the table components needed for a query given the currently selected database
2453 *
2454 * @param string $name Table name in the form of db.schema.table, db.table, or table
2455 * @return array (DB name or "" for default, schema name, table prefix, table name)
2456 */
2457 protected function qualifiedTableComponents( $name ) {
2458 # We reverse the explode so that database.table and table both output the correct table.
2459 $dbDetails = explode( '.', $name, 3 );
2460 if ( count( $dbDetails ) == 3 ) {
2461 list( $database, $schema, $table ) = $dbDetails;
2462 # We don't want any prefix added in this case
2463 $prefix = '';
2464 } elseif ( count( $dbDetails ) == 2 ) {
2465 list( $database, $table ) = $dbDetails;
2466 # We don't want any prefix added in this case
2467 $prefix = '';
2468 # In dbs that support it, $database may actually be the schema
2469 # but that doesn't affect any of the functionality here
2470 $schema = '';
2471 } else {
2472 list( $table ) = $dbDetails;
2473 if ( isset( $this->tableAliases[$table] ) ) {
2474 $database = $this->tableAliases[$table]['dbname'];
2475 $schema = is_string( $this->tableAliases[$table]['schema'] )
2476 ? $this->tableAliases[$table]['schema']
2477 : $this->relationSchemaQualifier();
2478 $prefix = is_string( $this->tableAliases[$table]['prefix'] )
2479 ? $this->tableAliases[$table]['prefix']
2480 : $this->tablePrefix();
2481 } else {
2482 $database = '';
2483 $schema = $this->relationSchemaQualifier(); # Default schema
2484 $prefix = $this->tablePrefix(); # Default prefix
2485 }
2486 }
2487
2488 return [ $database, $schema, $prefix, $table ];
2489 }
2490
2491 /**
2492 * @param string|null $namespace Database or schema
2493 * @param string $relation Name of table, view, sequence, etc...
2494 * @param string $format One of (raw, quoted)
2495 * @return string Relation name with quoted and merged $namespace as needed
2496 */
2497 private function prependDatabaseOrSchema( $namespace, $relation, $format ) {
2498 if ( strlen( $namespace ) ) {
2499 if ( $format === 'quoted' && !$this->isQuotedIdentifier( $namespace ) ) {
2500 $namespace = $this->addIdentifierQuotes( $namespace );
2501 }
2502 $relation = $namespace . '.' . $relation;
2503 }
2504
2505 return $relation;
2506 }
2507
2508 public function tableNames() {
2509 $inArray = func_get_args();
2510 $retVal = [];
2511
2512 foreach ( $inArray as $name ) {
2513 $retVal[$name] = $this->tableName( $name );
2514 }
2515
2516 return $retVal;
2517 }
2518
2519 public function tableNamesN() {
2520 $inArray = func_get_args();
2521 $retVal = [];
2522
2523 foreach ( $inArray as $name ) {
2524 $retVal[] = $this->tableName( $name );
2525 }
2526
2527 return $retVal;
2528 }
2529
2530 /**
2531 * Get an aliased table name
2532 *
2533 * This returns strings like "tableName AS newTableName" for aliased tables
2534 * and "(SELECT * from tableA) newTablename" for subqueries (e.g. derived tables)
2535 *
2536 * @see Database::tableName()
2537 * @param string|Subquery $table Table name or object with a 'sql' field
2538 * @param string|bool $alias Table alias (optional)
2539 * @return string SQL name for aliased table. Will not alias a table to its own name
2540 */
2541 protected function tableNameWithAlias( $table, $alias = false ) {
2542 if ( is_string( $table ) ) {
2543 $quotedTable = $this->tableName( $table );
2544 } elseif ( $table instanceof Subquery ) {
2545 $quotedTable = (string)$table;
2546 } else {
2547 throw new InvalidArgumentException( "Table must be a string or Subquery" );
2548 }
2549
2550 if ( $alias === false || $alias === $table ) {
2551 if ( $table instanceof Subquery ) {
2552 throw new InvalidArgumentException( "Subquery table missing alias" );
2553 }
2554
2555 return $quotedTable;
2556 } else {
2557 return $quotedTable . ' ' . $this->addIdentifierQuotes( $alias );
2558 }
2559 }
2560
2561 /**
2562 * Gets an array of aliased table names
2563 *
2564 * @param array $tables [ [alias] => table ]
2565 * @return string[] See tableNameWithAlias()
2566 */
2567 protected function tableNamesWithAlias( $tables ) {
2568 $retval = [];
2569 foreach ( $tables as $alias => $table ) {
2570 if ( is_numeric( $alias ) ) {
2571 $alias = $table;
2572 }
2573 $retval[] = $this->tableNameWithAlias( $table, $alias );
2574 }
2575
2576 return $retval;
2577 }
2578
2579 /**
2580 * Get an aliased field name
2581 * e.g. fieldName AS newFieldName
2582 *
2583 * @param string $name Field name
2584 * @param string|bool $alias Alias (optional)
2585 * @return string SQL name for aliased field. Will not alias a field to its own name
2586 */
2587 protected function fieldNameWithAlias( $name, $alias = false ) {
2588 if ( !$alias || (string)$alias === (string)$name ) {
2589 return $name;
2590 } else {
2591 return $name . ' AS ' . $this->addIdentifierQuotes( $alias ); // PostgreSQL needs AS
2592 }
2593 }
2594
2595 /**
2596 * Gets an array of aliased field names
2597 *
2598 * @param array $fields [ [alias] => field ]
2599 * @return string[] See fieldNameWithAlias()
2600 */
2601 protected function fieldNamesWithAlias( $fields ) {
2602 $retval = [];
2603 foreach ( $fields as $alias => $field ) {
2604 if ( is_numeric( $alias ) ) {
2605 $alias = $field;
2606 }
2607 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2608 }
2609
2610 return $retval;
2611 }
2612
2613 /**
2614 * Get the aliased table name clause for a FROM clause
2615 * which might have a JOIN and/or USE INDEX or IGNORE INDEX clause
2616 *
2617 * @param array $tables ( [alias] => table )
2618 * @param array $use_index Same as for select()
2619 * @param array $ignore_index Same as for select()
2620 * @param array $join_conds Same as for select()
2621 * @return string
2622 */
2623 protected function tableNamesWithIndexClauseOrJOIN(
2624 $tables, $use_index = [], $ignore_index = [], $join_conds = []
2625 ) {
2626 $ret = [];
2627 $retJOIN = [];
2628 $use_index = (array)$use_index;
2629 $ignore_index = (array)$ignore_index;
2630 $join_conds = (array)$join_conds;
2631
2632 foreach ( $tables as $alias => $table ) {
2633 if ( !is_string( $alias ) ) {
2634 // No alias? Set it equal to the table name
2635 $alias = $table;
2636 }
2637
2638 if ( is_array( $table ) ) {
2639 // A parenthesized group
2640 if ( count( $table ) > 1 ) {
2641 $joinedTable = '(' .
2642 $this->tableNamesWithIndexClauseOrJOIN(
2643 $table, $use_index, $ignore_index, $join_conds ) . ')';
2644 } else {
2645 // Degenerate case
2646 $innerTable = reset( $table );
2647 $innerAlias = key( $table );
2648 $joinedTable = $this->tableNameWithAlias(
2649 $innerTable,
2650 is_string( $innerAlias ) ? $innerAlias : $innerTable
2651 );
2652 }
2653 } else {
2654 $joinedTable = $this->tableNameWithAlias( $table, $alias );
2655 }
2656
2657 // Is there a JOIN clause for this table?
2658 if ( isset( $join_conds[$alias] ) ) {
2659 list( $joinType, $conds ) = $join_conds[$alias];
2660 $tableClause = $joinType;
2661 $tableClause .= ' ' . $joinedTable;
2662 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2663 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2664 if ( $use != '' ) {
2665 $tableClause .= ' ' . $use;
2666 }
2667 }
2668 if ( isset( $ignore_index[$alias] ) ) { // has IGNORE INDEX?
2669 $ignore = $this->ignoreIndexClause(
2670 implode( ',', (array)$ignore_index[$alias] ) );
2671 if ( $ignore != '' ) {
2672 $tableClause .= ' ' . $ignore;
2673 }
2674 }
2675 $on = $this->makeList( (array)$conds, self::LIST_AND );
2676 if ( $on != '' ) {
2677 $tableClause .= ' ON (' . $on . ')';
2678 }
2679
2680 $retJOIN[] = $tableClause;
2681 } elseif ( isset( $use_index[$alias] ) ) {
2682 // Is there an INDEX clause for this table?
2683 $tableClause = $joinedTable;
2684 $tableClause .= ' ' . $this->useIndexClause(
2685 implode( ',', (array)$use_index[$alias] )
2686 );
2687
2688 $ret[] = $tableClause;
2689 } elseif ( isset( $ignore_index[$alias] ) ) {
2690 // Is there an INDEX clause for this table?
2691 $tableClause = $joinedTable;
2692 $tableClause .= ' ' . $this->ignoreIndexClause(
2693 implode( ',', (array)$ignore_index[$alias] )
2694 );
2695
2696 $ret[] = $tableClause;
2697 } else {
2698 $tableClause = $joinedTable;
2699
2700 $ret[] = $tableClause;
2701 }
2702 }
2703
2704 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2705 $implicitJoins = implode( ',', $ret );
2706 $explicitJoins = implode( ' ', $retJOIN );
2707
2708 // Compile our final table clause
2709 return implode( ' ', [ $implicitJoins, $explicitJoins ] );
2710 }
2711
2712 /**
2713 * Allows for index remapping in queries where this is not consistent across DBMS
2714 *
2715 * @param string $index
2716 * @return string
2717 */
2718 protected function indexName( $index ) {
2719 return $this->indexAliases[$index] ?? $index;
2720 }
2721
2722 public function addQuotes( $s ) {
2723 if ( $s instanceof Blob ) {
2724 $s = $s->fetch();
2725 }
2726 if ( $s === null ) {
2727 return 'NULL';
2728 } elseif ( is_bool( $s ) ) {
2729 return (int)$s;
2730 } else {
2731 # This will also quote numeric values. This should be harmless,
2732 # and protects against weird problems that occur when they really
2733 # _are_ strings such as article titles and string->number->string
2734 # conversion is not 1:1.
2735 return "'" . $this->strencode( $s ) . "'";
2736 }
2737 }
2738
2739 public function addIdentifierQuotes( $s ) {
2740 return '"' . str_replace( '"', '""', $s ) . '"';
2741 }
2742
2743 /**
2744 * Returns if the given identifier looks quoted or not according to
2745 * the database convention for quoting identifiers .
2746 *
2747 * @note Do not use this to determine if untrusted input is safe.
2748 * A malicious user can trick this function.
2749 * @param string $name
2750 * @return bool
2751 */
2752 public function isQuotedIdentifier( $name ) {
2753 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2754 }
2755
2756 /**
2757 * @param string $s
2758 * @param string $escapeChar
2759 * @return string
2760 */
2761 protected function escapeLikeInternal( $s, $escapeChar = '`' ) {
2762 return str_replace( [ $escapeChar, '%', '_' ],
2763 [ "{$escapeChar}{$escapeChar}", "{$escapeChar}%", "{$escapeChar}_" ],
2764 $s );
2765 }
2766
2767 public function buildLike( $param, ...$params ) {
2768 if ( is_array( $param ) ) {
2769 $params = $param;
2770 } else {
2771 $params = func_get_args();
2772 }
2773
2774 $s = '';
2775
2776 // We use ` instead of \ as the default LIKE escape character, since addQuotes()
2777 // may escape backslashes, creating problems of double escaping. The `
2778 // character has good cross-DBMS compatibility, avoiding special operators
2779 // in MS SQL like ^ and %
2780 $escapeChar = '`';
2781
2782 foreach ( $params as $value ) {
2783 if ( $value instanceof LikeMatch ) {
2784 $s .= $value->toString();
2785 } else {
2786 $s .= $this->escapeLikeInternal( $value, $escapeChar );
2787 }
2788 }
2789
2790 return ' LIKE ' .
2791 $this->addQuotes( $s ) . ' ESCAPE ' . $this->addQuotes( $escapeChar ) . ' ';
2792 }
2793
2794 public function anyChar() {
2795 return new LikeMatch( '_' );
2796 }
2797
2798 public function anyString() {
2799 return new LikeMatch( '%' );
2800 }
2801
2802 public function nextSequenceValue( $seqName ) {
2803 return null;
2804 }
2805
2806 /**
2807 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2808 * is only needed because a) MySQL must be as efficient as possible due to
2809 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2810 * which index to pick. Anyway, other databases might have different
2811 * indexes on a given table. So don't bother overriding this unless you're
2812 * MySQL.
2813 * @param string $index
2814 * @return string
2815 */
2816 public function useIndexClause( $index ) {
2817 return '';
2818 }
2819
2820 /**
2821 * IGNORE INDEX clause. Unlikely to be useful for anything but MySQL. This
2822 * is only needed because a) MySQL must be as efficient as possible due to
2823 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2824 * which index to pick. Anyway, other databases might have different
2825 * indexes on a given table. So don't bother overriding this unless you're
2826 * MySQL.
2827 * @param string $index
2828 * @return string
2829 */
2830 public function ignoreIndexClause( $index ) {
2831 return '';
2832 }
2833
2834 public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
2835 if ( count( $rows ) == 0 ) {
2836 return;
2837 }
2838
2839 $uniqueIndexes = (array)$uniqueIndexes;
2840 // Single row case
2841 if ( !is_array( reset( $rows ) ) ) {
2842 $rows = [ $rows ];
2843 }
2844
2845 try {
2846 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
2847 $affectedRowCount = 0;
2848 foreach ( $rows as $row ) {
2849 // Delete rows which collide with this one
2850 $indexWhereClauses = [];
2851 foreach ( $uniqueIndexes as $index ) {
2852 $indexColumns = (array)$index;
2853 $indexRowValues = array_intersect_key( $row, array_flip( $indexColumns ) );
2854 if ( count( $indexRowValues ) != count( $indexColumns ) ) {
2855 throw new DBUnexpectedError(
2856 $this,
2857 'New record does not provide all values for unique key (' .
2858 implode( ', ', $indexColumns ) . ')'
2859 );
2860 } elseif ( in_array( null, $indexRowValues, true ) ) {
2861 throw new DBUnexpectedError(
2862 $this,
2863 'New record has a null value for unique key (' .
2864 implode( ', ', $indexColumns ) . ')'
2865 );
2866 }
2867 $indexWhereClauses[] = $this->makeList( $indexRowValues, LIST_AND );
2868 }
2869
2870 if ( $indexWhereClauses ) {
2871 $this->delete( $table, $this->makeList( $indexWhereClauses, LIST_OR ), $fname );
2872 $affectedRowCount += $this->affectedRows();
2873 }
2874
2875 // Now insert the row
2876 $this->insert( $table, $row, $fname );
2877 $affectedRowCount += $this->affectedRows();
2878 }
2879 $this->endAtomic( $fname );
2880 $this->affectedRowCount = $affectedRowCount;
2881 } catch ( Exception $e ) {
2882 $this->cancelAtomic( $fname );
2883 throw $e;
2884 }
2885 }
2886
2887 /**
2888 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2889 * statement.
2890 *
2891 * @param string $table Table name
2892 * @param array|string $rows Row(s) to insert
2893 * @param string $fname Caller function name
2894 */
2895 protected function nativeReplace( $table, $rows, $fname ) {
2896 $table = $this->tableName( $table );
2897
2898 # Single row case
2899 if ( !is_array( reset( $rows ) ) ) {
2900 $rows = [ $rows ];
2901 }
2902
2903 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2904 $first = true;
2905
2906 foreach ( $rows as $row ) {
2907 if ( $first ) {
2908 $first = false;
2909 } else {
2910 $sql .= ',';
2911 }
2912
2913 $sql .= '(' . $this->makeList( $row ) . ')';
2914 }
2915
2916 $this->query( $sql, $fname );
2917 }
2918
2919 public function upsert( $table, array $rows, $uniqueIndexes, array $set,
2920 $fname = __METHOD__
2921 ) {
2922 if ( $rows === [] ) {
2923 return true; // nothing to do
2924 }
2925
2926 $uniqueIndexes = (array)$uniqueIndexes;
2927 if ( !is_array( reset( $rows ) ) ) {
2928 $rows = [ $rows ];
2929 }
2930
2931 if ( count( $uniqueIndexes ) ) {
2932 $clauses = []; // list WHERE clauses that each identify a single row
2933 foreach ( $rows as $row ) {
2934 foreach ( $uniqueIndexes as $index ) {
2935 $index = is_array( $index ) ? $index : [ $index ]; // columns
2936 $rowKey = []; // unique key to this row
2937 foreach ( $index as $column ) {
2938 $rowKey[$column] = $row[$column];
2939 }
2940 $clauses[] = $this->makeList( $rowKey, self::LIST_AND );
2941 }
2942 }
2943 $where = [ $this->makeList( $clauses, self::LIST_OR ) ];
2944 } else {
2945 $where = false;
2946 }
2947
2948 $affectedRowCount = 0;
2949 try {
2950 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
2951 # Update any existing conflicting row(s)
2952 if ( $where !== false ) {
2953 $this->update( $table, $set, $where, $fname );
2954 $affectedRowCount += $this->affectedRows();
2955 }
2956 # Now insert any non-conflicting row(s)
2957 $this->insert( $table, $rows, $fname, [ 'IGNORE' ] );
2958 $affectedRowCount += $this->affectedRows();
2959 $this->endAtomic( $fname );
2960 $this->affectedRowCount = $affectedRowCount;
2961 } catch ( Exception $e ) {
2962 $this->cancelAtomic( $fname );
2963 throw $e;
2964 }
2965
2966 return true;
2967 }
2968
2969 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2970 $fname = __METHOD__
2971 ) {
2972 if ( !$conds ) {
2973 throw new DBUnexpectedError( $this, __METHOD__ . ' called with empty $conds' );
2974 }
2975
2976 $delTable = $this->tableName( $delTable );
2977 $joinTable = $this->tableName( $joinTable );
2978 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2979 if ( $conds != '*' ) {
2980 $sql .= 'WHERE ' . $this->makeList( $conds, self::LIST_AND );
2981 }
2982 $sql .= ')';
2983
2984 $this->query( $sql, $fname );
2985 }
2986
2987 public function textFieldSize( $table, $field ) {
2988 $table = $this->tableName( $table );
2989 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\"";
2990 $res = $this->query( $sql, __METHOD__ );
2991 $row = $this->fetchObject( $res );
2992
2993 $m = [];
2994
2995 if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
2996 $size = $m[1];
2997 } else {
2998 $size = -1;
2999 }
3000
3001 return $size;
3002 }
3003
3004 public function delete( $table, $conds, $fname = __METHOD__ ) {
3005 if ( !$conds ) {
3006 throw new DBUnexpectedError( $this, __METHOD__ . ' called with no conditions' );
3007 }
3008
3009 $table = $this->tableName( $table );
3010 $sql = "DELETE FROM $table";
3011
3012 if ( $conds != '*' ) {
3013 if ( is_array( $conds ) ) {
3014 $conds = $this->makeList( $conds, self::LIST_AND );
3015 }
3016 $sql .= ' WHERE ' . $conds;
3017 }
3018
3019 $this->query( $sql, $fname );
3020
3021 return true;
3022 }
3023
3024 final public function insertSelect(
3025 $destTable, $srcTable, $varMap, $conds,
3026 $fname = __METHOD__, $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3027 ) {
3028 static $hints = [ 'NO_AUTO_COLUMNS' ];
3029
3030 $insertOptions = (array)$insertOptions;
3031 $selectOptions = (array)$selectOptions;
3032
3033 if ( $this->cliMode && $this->isInsertSelectSafe( $insertOptions, $selectOptions ) ) {
3034 // For massive migrations with downtime, we don't want to select everything
3035 // into memory and OOM, so do all this native on the server side if possible.
3036 $this->nativeInsertSelect(
3037 $destTable,
3038 $srcTable,
3039 $varMap,
3040 $conds,
3041 $fname,
3042 array_diff( $insertOptions, $hints ),
3043 $selectOptions,
3044 $selectJoinConds
3045 );
3046 } else {
3047 $this->nonNativeInsertSelect(
3048 $destTable,
3049 $srcTable,
3050 $varMap,
3051 $conds,
3052 $fname,
3053 array_diff( $insertOptions, $hints ),
3054 $selectOptions,
3055 $selectJoinConds
3056 );
3057 }
3058
3059 return true;
3060 }
3061
3062 /**
3063 * @param array $insertOptions INSERT options
3064 * @param array $selectOptions SELECT options
3065 * @return bool Whether an INSERT SELECT with these options will be replication safe
3066 * @since 1.31
3067 */
3068 protected function isInsertSelectSafe( array $insertOptions, array $selectOptions ) {
3069 return true;
3070 }
3071
3072 /**
3073 * Implementation of insertSelect() based on select() and insert()
3074 *
3075 * @see IDatabase::insertSelect()
3076 * @since 1.30
3077 * @param string $destTable
3078 * @param string|array $srcTable
3079 * @param array $varMap
3080 * @param array $conds
3081 * @param string $fname
3082 * @param array $insertOptions
3083 * @param array $selectOptions
3084 * @param array $selectJoinConds
3085 */
3086 protected function nonNativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
3087 $fname = __METHOD__,
3088 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3089 ) {
3090 // For web requests, do a locking SELECT and then INSERT. This puts the SELECT burden
3091 // on only the master (without needing row-based-replication). It also makes it easy to
3092 // know how big the INSERT is going to be.
3093 $fields = [];
3094 foreach ( $varMap as $dstColumn => $sourceColumnOrSql ) {
3095 $fields[] = $this->fieldNameWithAlias( $sourceColumnOrSql, $dstColumn );
3096 }
3097 $selectOptions[] = 'FOR UPDATE';
3098 $res = $this->select(
3099 $srcTable, implode( ',', $fields ), $conds, $fname, $selectOptions, $selectJoinConds
3100 );
3101 if ( !$res ) {
3102 return;
3103 }
3104
3105 try {
3106 $affectedRowCount = 0;
3107 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
3108 $rows = [];
3109 $ok = true;
3110 foreach ( $res as $row ) {
3111 $rows[] = (array)$row;
3112
3113 // Avoid inserts that are too huge
3114 if ( count( $rows ) >= $this->nonNativeInsertSelectBatchSize ) {
3115 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
3116 if ( !$ok ) {
3117 break;
3118 }
3119 $affectedRowCount += $this->affectedRows();
3120 $rows = [];
3121 }
3122 }
3123 if ( $rows && $ok ) {
3124 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
3125 if ( $ok ) {
3126 $affectedRowCount += $this->affectedRows();
3127 }
3128 }
3129 if ( $ok ) {
3130 $this->endAtomic( $fname );
3131 $this->affectedRowCount = $affectedRowCount;
3132 } else {
3133 $this->cancelAtomic( $fname );
3134 }
3135 } catch ( Exception $e ) {
3136 $this->cancelAtomic( $fname );
3137 throw $e;
3138 }
3139 }
3140
3141 /**
3142 * Native server-side implementation of insertSelect() for situations where
3143 * we don't want to select everything into memory
3144 *
3145 * @see IDatabase::insertSelect()
3146 * @param string $destTable
3147 * @param string|array $srcTable
3148 * @param array $varMap
3149 * @param array $conds
3150 * @param string $fname
3151 * @param array $insertOptions
3152 * @param array $selectOptions
3153 * @param array $selectJoinConds
3154 */
3155 protected function nativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
3156 $fname = __METHOD__,
3157 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3158 ) {
3159 $destTable = $this->tableName( $destTable );
3160
3161 if ( !is_array( $insertOptions ) ) {
3162 $insertOptions = [ $insertOptions ];
3163 }
3164
3165 $insertOptions = $this->makeInsertOptions( $insertOptions );
3166
3167 $selectSql = $this->selectSQLText(
3168 $srcTable,
3169 array_values( $varMap ),
3170 $conds,
3171 $fname,
3172 $selectOptions,
3173 $selectJoinConds
3174 );
3175
3176 $sql = "INSERT $insertOptions" .
3177 " INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ') ' .
3178 $selectSql;
3179
3180 $this->query( $sql, $fname );
3181 }
3182
3183 public function limitResult( $sql, $limit, $offset = false ) {
3184 if ( !is_numeric( $limit ) ) {
3185 throw new DBUnexpectedError(
3186 $this,
3187 "Invalid non-numeric limit passed to " . __METHOD__
3188 );
3189 }
3190 // This version works in MySQL and SQLite. It will very likely need to be
3191 // overridden for most other RDBMS subclasses.
3192 return "$sql LIMIT "
3193 . ( ( is_numeric( $offset ) && $offset != 0 ) ? "{$offset}," : "" )
3194 . "{$limit} ";
3195 }
3196
3197 public function unionSupportsOrderAndLimit() {
3198 return true; // True for almost every DB supported
3199 }
3200
3201 public function unionQueries( $sqls, $all ) {
3202 $glue = $all ? ') UNION ALL (' : ') UNION (';
3203
3204 return '(' . implode( $glue, $sqls ) . ')';
3205 }
3206
3207 public function unionConditionPermutations(
3208 $table, $vars, array $permute_conds, $extra_conds = '', $fname = __METHOD__,
3209 $options = [], $join_conds = []
3210 ) {
3211 // First, build the Cartesian product of $permute_conds
3212 $conds = [ [] ];
3213 foreach ( $permute_conds as $field => $values ) {
3214 if ( !$values ) {
3215 // Skip empty $values
3216 continue;
3217 }
3218 $values = array_unique( $values ); // For sanity
3219 $newConds = [];
3220 foreach ( $conds as $cond ) {
3221 foreach ( $values as $value ) {
3222 $cond[$field] = $value;
3223 $newConds[] = $cond; // Arrays are by-value, not by-reference, so this works
3224 }
3225 }
3226 $conds = $newConds;
3227 }
3228
3229 $extra_conds = $extra_conds === '' ? [] : (array)$extra_conds;
3230
3231 // If there's just one condition and no subordering, hand off to
3232 // selectSQLText directly.
3233 if ( count( $conds ) === 1 &&
3234 ( !isset( $options['INNER ORDER BY'] ) || !$this->unionSupportsOrderAndLimit() )
3235 ) {
3236 return $this->selectSQLText(
3237 $table, $vars, $conds[0] + $extra_conds, $fname, $options, $join_conds
3238 );
3239 }
3240
3241 // Otherwise, we need to pull out the order and limit to apply after
3242 // the union. Then build the SQL queries for each set of conditions in
3243 // $conds. Then union them together (using UNION ALL, because the
3244 // product *should* already be distinct).
3245 $orderBy = $this->makeOrderBy( $options );
3246 $limit = $options['LIMIT'] ?? null;
3247 $offset = $options['OFFSET'] ?? false;
3248 $all = empty( $options['NOTALL'] ) && !in_array( 'NOTALL', $options );
3249 if ( !$this->unionSupportsOrderAndLimit() ) {
3250 unset( $options['ORDER BY'], $options['LIMIT'], $options['OFFSET'] );
3251 } else {
3252 if ( array_key_exists( 'INNER ORDER BY', $options ) ) {
3253 $options['ORDER BY'] = $options['INNER ORDER BY'];
3254 }
3255 if ( $limit !== null && is_numeric( $offset ) && $offset != 0 ) {
3256 // We need to increase the limit by the offset rather than
3257 // using the offset directly, otherwise it'll skip incorrectly
3258 // in the subqueries.
3259 $options['LIMIT'] = $limit + $offset;
3260 unset( $options['OFFSET'] );
3261 }
3262 }
3263
3264 $sqls = [];
3265 foreach ( $conds as $cond ) {
3266 $sqls[] = $this->selectSQLText(
3267 $table, $vars, $cond + $extra_conds, $fname, $options, $join_conds
3268 );
3269 }
3270 $sql = $this->unionQueries( $sqls, $all ) . $orderBy;
3271 if ( $limit !== null ) {
3272 $sql = $this->limitResult( $sql, $limit, $offset );
3273 }
3274
3275 return $sql;
3276 }
3277
3278 public function conditional( $cond, $trueVal, $falseVal ) {
3279 if ( is_array( $cond ) ) {
3280 $cond = $this->makeList( $cond, self::LIST_AND );
3281 }
3282
3283 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
3284 }
3285
3286 public function strreplace( $orig, $old, $new ) {
3287 return "REPLACE({$orig}, {$old}, {$new})";
3288 }
3289
3290 public function getServerUptime() {
3291 return 0;
3292 }
3293
3294 public function wasDeadlock() {
3295 return false;
3296 }
3297
3298 public function wasLockTimeout() {
3299 return false;
3300 }
3301
3302 public function wasConnectionLoss() {
3303 return $this->wasConnectionError( $this->lastErrno() );
3304 }
3305
3306 public function wasReadOnlyError() {
3307 return false;
3308 }
3309
3310 public function wasErrorReissuable() {
3311 return (
3312 $this->wasDeadlock() ||
3313 $this->wasLockTimeout() ||
3314 $this->wasConnectionLoss()
3315 );
3316 }
3317
3318 /**
3319 * Do not use this method outside of Database/DBError classes
3320 *
3321 * @param int|string $errno
3322 * @return bool Whether the given query error was a connection drop
3323 */
3324 public function wasConnectionError( $errno ) {
3325 return false;
3326 }
3327
3328 /**
3329 * @return bool Whether it is known that the last query error only caused statement rollback
3330 * @note This is for backwards compatibility for callers catching DBError exceptions in
3331 * order to ignore problems like duplicate key errors or foriegn key violations
3332 * @since 1.31
3333 */
3334 protected function wasKnownStatementRollbackError() {
3335 return false; // don't know; it could have caused a transaction rollback
3336 }
3337
3338 public function deadlockLoop() {
3339 $args = func_get_args();
3340 $function = array_shift( $args );
3341 $tries = self::$DEADLOCK_TRIES;
3342
3343 $this->begin( __METHOD__ );
3344
3345 $retVal = null;
3346 /** @var Exception $e */
3347 $e = null;
3348 do {
3349 try {
3350 $retVal = $function( ...$args );
3351 break;
3352 } catch ( DBQueryError $e ) {
3353 if ( $this->wasDeadlock() ) {
3354 // Retry after a randomized delay
3355 usleep( mt_rand( self::$DEADLOCK_DELAY_MIN, self::$DEADLOCK_DELAY_MAX ) );
3356 } else {
3357 // Throw the error back up
3358 throw $e;
3359 }
3360 }
3361 } while ( --$tries > 0 );
3362
3363 if ( $tries <= 0 ) {
3364 // Too many deadlocks; give up
3365 $this->rollback( __METHOD__ );
3366 throw $e;
3367 } else {
3368 $this->commit( __METHOD__ );
3369
3370 return $retVal;
3371 }
3372 }
3373
3374 public function masterPosWait( DBMasterPos $pos, $timeout ) {
3375 # Real waits are implemented in the subclass.
3376 return 0;
3377 }
3378
3379 public function getReplicaPos() {
3380 # Stub
3381 return false;
3382 }
3383
3384 public function getMasterPos() {
3385 # Stub
3386 return false;
3387 }
3388
3389 public function serverIsReadOnly() {
3390 return false;
3391 }
3392
3393 final public function onTransactionResolution( callable $callback, $fname = __METHOD__ ) {
3394 if ( !$this->trxLevel() ) {
3395 throw new DBUnexpectedError( $this, "No transaction is active" );
3396 }
3397 $this->trxEndCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3398 }
3399
3400 final public function onTransactionCommitOrIdle( callable $callback, $fname = __METHOD__ ) {
3401 if ( !$this->trxLevel() && $this->getTransactionRoundId() ) {
3402 // Start an implicit transaction similar to how query() does
3403 $this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
3404 $this->trxAutomatic = true;
3405 }
3406
3407 $this->trxIdleCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3408 if ( !$this->trxLevel() ) {
3409 $this->runOnTransactionIdleCallbacks( self::TRIGGER_IDLE );
3410 }
3411 }
3412
3413 final public function onTransactionIdle( callable $callback, $fname = __METHOD__ ) {
3414 $this->onTransactionCommitOrIdle( $callback, $fname );
3415 }
3416
3417 final public function onTransactionPreCommitOrIdle( callable $callback, $fname = __METHOD__ ) {
3418 if ( !$this->trxLevel() && $this->getTransactionRoundId() ) {
3419 // Start an implicit transaction similar to how query() does
3420 $this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
3421 $this->trxAutomatic = true;
3422 }
3423
3424 if ( $this->trxLevel() ) {
3425 $this->trxPreCommitCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3426 } else {
3427 // No transaction is active nor will start implicitly, so make one for this callback
3428 $this->startAtomic( __METHOD__, self::ATOMIC_CANCELABLE );
3429 try {
3430 $callback( $this );
3431 $this->endAtomic( __METHOD__ );
3432 } catch ( Exception $e ) {
3433 $this->cancelAtomic( __METHOD__ );
3434 throw $e;
3435 }
3436 }
3437 }
3438
3439 final public function onAtomicSectionCancel( callable $callback, $fname = __METHOD__ ) {
3440 if ( !$this->trxLevel() || !$this->trxAtomicLevels ) {
3441 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)" );
3442 }
3443 $this->trxSectionCancelCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3444 }
3445
3446 /**
3447 * @return AtomicSectionIdentifier|null ID of the topmost atomic section level
3448 */
3449 private function currentAtomicSectionId() {
3450 if ( $this->trxLevel() && $this->trxAtomicLevels ) {
3451 $levelInfo = end( $this->trxAtomicLevels );
3452
3453 return $levelInfo[1];
3454 }
3455
3456 return null;
3457 }
3458
3459 /**
3460 * Hoist callback ownership for callbacks in a section to a parent section.
3461 * All callbacks should have an owner that is present in trxAtomicLevels.
3462 * @param AtomicSectionIdentifier $old
3463 * @param AtomicSectionIdentifier $new
3464 */
3465 private function reassignCallbacksForSection(
3466 AtomicSectionIdentifier $old, AtomicSectionIdentifier $new
3467 ) {
3468 foreach ( $this->trxPreCommitCallbacks as $key => $info ) {
3469 if ( $info[2] === $old ) {
3470 $this->trxPreCommitCallbacks[$key][2] = $new;
3471 }
3472 }
3473 foreach ( $this->trxIdleCallbacks as $key => $info ) {
3474 if ( $info[2] === $old ) {
3475 $this->trxIdleCallbacks[$key][2] = $new;
3476 }
3477 }
3478 foreach ( $this->trxEndCallbacks as $key => $info ) {
3479 if ( $info[2] === $old ) {
3480 $this->trxEndCallbacks[$key][2] = $new;
3481 }
3482 }
3483 foreach ( $this->trxSectionCancelCallbacks as $key => $info ) {
3484 if ( $info[2] === $old ) {
3485 $this->trxSectionCancelCallbacks[$key][2] = $new;
3486 }
3487 }
3488 }
3489
3490 /**
3491 * Update callbacks that were owned by cancelled atomic sections.
3492 *
3493 * Callbacks for "on commit" should never be run if they're owned by a
3494 * section that won't be committed.
3495 *
3496 * Callbacks for "on resolution" need to reflect that the section was
3497 * rolled back, even if the transaction as a whole commits successfully.
3498 *
3499 * Callbacks for "on section cancel" should already have been consumed,
3500 * but errors during the cancellation itself can prevent that while still
3501 * destroying the section. Hoist any such callbacks to the new top section,
3502 * which we assume will itself have to be cancelled or rolled back to
3503 * resolve the error.
3504 *
3505 * @param AtomicSectionIdentifier[] $sectionIds ID of an actual savepoint
3506 * @param AtomicSectionIdentifier|null $newSectionId New top section ID.
3507 * @throws UnexpectedValueException
3508 */
3509 private function modifyCallbacksForCancel(
3510 array $sectionIds, AtomicSectionIdentifier $newSectionId = null
3511 ) {
3512 // Cancel the "on commit" callbacks owned by this savepoint
3513 $this->trxIdleCallbacks = array_filter(
3514 $this->trxIdleCallbacks,
3515 function ( $entry ) use ( $sectionIds ) {
3516 return !in_array( $entry[2], $sectionIds, true );
3517 }
3518 );
3519 $this->trxPreCommitCallbacks = array_filter(
3520 $this->trxPreCommitCallbacks,
3521 function ( $entry ) use ( $sectionIds ) {
3522 return !in_array( $entry[2], $sectionIds, true );
3523 }
3524 );
3525 // Make "on resolution" callbacks owned by this savepoint to perceive a rollback
3526 foreach ( $this->trxEndCallbacks as $key => $entry ) {
3527 if ( in_array( $entry[2], $sectionIds, true ) ) {
3528 $callback = $entry[0];
3529 $this->trxEndCallbacks[$key][0] = function () use ( $callback ) {
3530 // @phan-suppress-next-line PhanInfiniteRecursion No recursion at all here, phan is confused
3531 return $callback( self::TRIGGER_ROLLBACK, $this );
3532 };
3533 // This "on resolution" callback no longer belongs to a section.
3534 $this->trxEndCallbacks[$key][2] = null;
3535 }
3536 }
3537 // Hoist callback ownership for section cancel callbacks to the new top section
3538 foreach ( $this->trxSectionCancelCallbacks as $key => $entry ) {
3539 if ( in_array( $entry[2], $sectionIds, true ) ) {
3540 $this->trxSectionCancelCallbacks[$key][2] = $newSectionId;
3541 }
3542 }
3543 }
3544
3545 final public function setTransactionListener( $name, callable $callback = null ) {
3546 if ( $callback ) {
3547 $this->trxRecurringCallbacks[$name] = $callback;
3548 } else {
3549 unset( $this->trxRecurringCallbacks[$name] );
3550 }
3551 }
3552
3553 /**
3554 * Whether to disable running of post-COMMIT/ROLLBACK callbacks
3555 *
3556 * This method should not be used outside of Database/LoadBalancer
3557 *
3558 * @param bool $suppress
3559 * @since 1.28
3560 */
3561 final public function setTrxEndCallbackSuppression( $suppress ) {
3562 $this->trxEndCallbacksSuppressed = $suppress;
3563 }
3564
3565 /**
3566 * Actually consume and run any "on transaction idle/resolution" callbacks.
3567 *
3568 * This method should not be used outside of Database/LoadBalancer
3569 *
3570 * @param int $trigger IDatabase::TRIGGER_* constant
3571 * @return int Number of callbacks attempted
3572 * @since 1.20
3573 * @throws Exception
3574 */
3575 public function runOnTransactionIdleCallbacks( $trigger ) {
3576 if ( $this->trxLevel() ) { // sanity
3577 throw new DBUnexpectedError( $this, __METHOD__ . ': a transaction is still open' );
3578 }
3579
3580 if ( $this->trxEndCallbacksSuppressed ) {
3581 return 0;
3582 }
3583
3584 $count = 0;
3585 $autoTrx = $this->getFlag( self::DBO_TRX ); // automatic begin() enabled?
3586 /** @var Exception $e */
3587 $e = null; // first exception
3588 do { // callbacks may add callbacks :)
3589 $callbacks = array_merge(
3590 $this->trxIdleCallbacks,
3591 $this->trxEndCallbacks // include "transaction resolution" callbacks
3592 );
3593 $this->trxIdleCallbacks = []; // consumed (and recursion guard)
3594 $this->trxEndCallbacks = []; // consumed (recursion guard)
3595
3596 // Only run trxSectionCancelCallbacks on rollback, not commit.
3597 // But always consume them.
3598 if ( $trigger === self::TRIGGER_ROLLBACK ) {
3599 $callbacks = array_merge( $callbacks, $this->trxSectionCancelCallbacks );
3600 }
3601 $this->trxSectionCancelCallbacks = []; // consumed (recursion guard)
3602
3603 foreach ( $callbacks as $callback ) {
3604 ++$count;
3605 list( $phpCallback ) = $callback;
3606 $this->clearFlag( self::DBO_TRX ); // make each query its own transaction
3607 try {
3608 // @phan-suppress-next-line PhanParamTooManyCallable
3609 call_user_func( $phpCallback, $trigger, $this );
3610 } catch ( Exception $ex ) {
3611 call_user_func( $this->errorLogger, $ex );
3612 $e = $e ?: $ex;
3613 // Some callbacks may use startAtomic/endAtomic, so make sure
3614 // their transactions are ended so other callbacks don't fail
3615 if ( $this->trxLevel() ) {
3616 $this->rollback( __METHOD__, self::FLUSHING_INTERNAL );
3617 }
3618 } finally {
3619 if ( $autoTrx ) {
3620 $this->setFlag( self::DBO_TRX ); // restore automatic begin()
3621 } else {
3622 $this->clearFlag( self::DBO_TRX ); // restore auto-commit
3623 }
3624 }
3625 }
3626 } while ( count( $this->trxIdleCallbacks ) );
3627
3628 if ( $e instanceof Exception ) {
3629 throw $e; // re-throw any first exception
3630 }
3631
3632 return $count;
3633 }
3634
3635 /**
3636 * Actually consume and run any "on transaction pre-commit" callbacks.
3637 *
3638 * This method should not be used outside of Database/LoadBalancer
3639 *
3640 * @since 1.22
3641 * @return int Number of callbacks attempted
3642 * @throws Exception
3643 */
3644 public function runOnTransactionPreCommitCallbacks() {
3645 $count = 0;
3646
3647 $e = null; // first exception
3648 do { // callbacks may add callbacks :)
3649 $callbacks = $this->trxPreCommitCallbacks;
3650 $this->trxPreCommitCallbacks = []; // consumed (and recursion guard)
3651 foreach ( $callbacks as $callback ) {
3652 try {
3653 ++$count;
3654 list( $phpCallback ) = $callback;
3655 $phpCallback( $this );
3656 } catch ( Exception $ex ) {
3657 ( $this->errorLogger )( $ex );
3658 $e = $e ?: $ex;
3659 }
3660 }
3661 } while ( count( $this->trxPreCommitCallbacks ) );
3662
3663 if ( $e instanceof Exception ) {
3664 throw $e; // re-throw any first exception
3665 }
3666
3667 return $count;
3668 }
3669
3670 /**
3671 * Actually run any "atomic section cancel" callbacks.
3672 *
3673 * @param int $trigger IDatabase::TRIGGER_* constant
3674 * @param AtomicSectionIdentifier[]|null $sectionIds Section IDs to cancel,
3675 * null on transaction rollback
3676 */
3677 private function runOnAtomicSectionCancelCallbacks(
3678 $trigger, array $sectionIds = null
3679 ) {
3680 /** @var Exception|Throwable $e */
3681 $e = null; // first exception
3682
3683 $notCancelled = [];
3684 do {
3685 $callbacks = $this->trxSectionCancelCallbacks;
3686 $this->trxSectionCancelCallbacks = []; // consumed (recursion guard)
3687 foreach ( $callbacks as $entry ) {
3688 if ( $sectionIds === null || in_array( $entry[2], $sectionIds, true ) ) {
3689 try {
3690 $entry[0]( $trigger, $this );
3691 } catch ( Exception $ex ) {
3692 ( $this->errorLogger )( $ex );
3693 $e = $e ?: $ex;
3694 } catch ( Throwable $ex ) {
3695 // @todo: Log?
3696 $e = $e ?: $ex;
3697 }
3698 } else {
3699 $notCancelled[] = $entry;
3700 }
3701 }
3702 } while ( count( $this->trxSectionCancelCallbacks ) );
3703 $this->trxSectionCancelCallbacks = $notCancelled;
3704
3705 if ( $e !== null ) {
3706 throw $e; // re-throw any first Exception/Throwable
3707 }
3708 }
3709
3710 /**
3711 * Actually run any "transaction listener" callbacks.
3712 *
3713 * This method should not be used outside of Database/LoadBalancer
3714 *
3715 * @param int $trigger IDatabase::TRIGGER_* constant
3716 * @throws Exception
3717 * @since 1.20
3718 */
3719 public function runTransactionListenerCallbacks( $trigger ) {
3720 if ( $this->trxEndCallbacksSuppressed ) {
3721 return;
3722 }
3723
3724 /** @var Exception $e */
3725 $e = null; // first exception
3726
3727 foreach ( $this->trxRecurringCallbacks as $phpCallback ) {
3728 try {
3729 $phpCallback( $trigger, $this );
3730 } catch ( Exception $ex ) {
3731 ( $this->errorLogger )( $ex );
3732 $e = $e ?: $ex;
3733 }
3734 }
3735
3736 if ( $e instanceof Exception ) {
3737 throw $e; // re-throw any first exception
3738 }
3739 }
3740
3741 /**
3742 * Create a savepoint
3743 *
3744 * This is used internally to implement atomic sections. It should not be
3745 * used otherwise.
3746 *
3747 * @since 1.31
3748 * @param string $identifier Identifier for the savepoint
3749 * @param string $fname Calling function name
3750 */
3751 protected function doSavepoint( $identifier, $fname ) {
3752 $this->query( 'SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3753 }
3754
3755 /**
3756 * Release a savepoint
3757 *
3758 * This is used internally to implement atomic sections. It should not be
3759 * used otherwise.
3760 *
3761 * @since 1.31
3762 * @param string $identifier Identifier for the savepoint
3763 * @param string $fname Calling function name
3764 */
3765 protected function doReleaseSavepoint( $identifier, $fname ) {
3766 $this->query( 'RELEASE SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3767 }
3768
3769 /**
3770 * Rollback to a savepoint
3771 *
3772 * This is used internally to implement atomic sections. It should not be
3773 * used otherwise.
3774 *
3775 * @since 1.31
3776 * @param string $identifier Identifier for the savepoint
3777 * @param string $fname Calling function name
3778 */
3779 protected function doRollbackToSavepoint( $identifier, $fname ) {
3780 $this->query( 'ROLLBACK TO SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3781 }
3782
3783 /**
3784 * @param string $fname
3785 * @return string
3786 */
3787 private function nextSavepointId( $fname ) {
3788 $savepointId = self::$SAVEPOINT_PREFIX . ++$this->trxAtomicCounter;
3789 if ( strlen( $savepointId ) > 30 ) {
3790 // 30 == Oracle's identifier length limit (pre 12c)
3791 // With a 22 character prefix, that puts the highest number at 99999999.
3792 throw new DBUnexpectedError(
3793 $this,
3794 'There have been an excessively large number of atomic sections in a transaction'
3795 . " started by $this->trxFname (at $fname)"
3796 );
3797 }
3798
3799 return $savepointId;
3800 }
3801
3802 final public function startAtomic(
3803 $fname = __METHOD__, $cancelable = self::ATOMIC_NOT_CANCELABLE
3804 ) {
3805 $savepointId = $cancelable === self::ATOMIC_CANCELABLE ? self::$NOT_APPLICABLE : null;
3806
3807 if ( !$this->trxLevel() ) {
3808 $this->begin( $fname, self::TRANSACTION_INTERNAL ); // sets trxAutomatic
3809 // If DBO_TRX is set, a series of startAtomic/endAtomic pairs will result
3810 // in all changes being in one transaction to keep requests transactional.
3811 if ( $this->getFlag( self::DBO_TRX ) ) {
3812 // Since writes could happen in between the topmost atomic sections as part
3813 // of the transaction, those sections will need savepoints.
3814 $savepointId = $this->nextSavepointId( $fname );
3815 $this->doSavepoint( $savepointId, $fname );
3816 } else {
3817 $this->trxAutomaticAtomic = true;
3818 }
3819 } elseif ( $cancelable === self::ATOMIC_CANCELABLE ) {
3820 $savepointId = $this->nextSavepointId( $fname );
3821 $this->doSavepoint( $savepointId, $fname );
3822 }
3823
3824 $sectionId = new AtomicSectionIdentifier;
3825 $this->trxAtomicLevels[] = [ $fname, $sectionId, $savepointId ];
3826 $this->queryLogger->debug( 'startAtomic: entering level ' .
3827 ( count( $this->trxAtomicLevels ) - 1 ) . " ($fname)" );
3828
3829 return $sectionId;
3830 }
3831
3832 final public function endAtomic( $fname = __METHOD__ ) {
3833 if ( !$this->trxLevel() || !$this->trxAtomicLevels ) {
3834 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)" );
3835 }
3836
3837 // Check if the current section matches $fname
3838 $pos = count( $this->trxAtomicLevels ) - 1;
3839 list( $savedFname, $sectionId, $savepointId ) = $this->trxAtomicLevels[$pos];
3840 $this->queryLogger->debug( "endAtomic: leaving level $pos ($fname)" );
3841
3842 if ( $savedFname !== $fname ) {
3843 throw new DBUnexpectedError(
3844 $this,
3845 "Invalid atomic section ended (got $fname but expected $savedFname)"
3846 );
3847 }
3848
3849 // Remove the last section (no need to re-index the array)
3850 array_pop( $this->trxAtomicLevels );
3851
3852 if ( !$this->trxAtomicLevels && $this->trxAutomaticAtomic ) {
3853 $this->commit( $fname, self::FLUSHING_INTERNAL );
3854 } elseif ( $savepointId !== null && $savepointId !== self::$NOT_APPLICABLE ) {
3855 $this->doReleaseSavepoint( $savepointId, $fname );
3856 }
3857
3858 // Hoist callback ownership for callbacks in the section that just ended;
3859 // all callbacks should have an owner that is present in trxAtomicLevels.
3860 $currentSectionId = $this->currentAtomicSectionId();
3861 if ( $currentSectionId ) {
3862 $this->reassignCallbacksForSection( $sectionId, $currentSectionId );
3863 }
3864 }
3865
3866 final public function cancelAtomic(
3867 $fname = __METHOD__, AtomicSectionIdentifier $sectionId = null
3868 ) {
3869 if ( !$this->trxLevel() || !$this->trxAtomicLevels ) {
3870 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)" );
3871 }
3872
3873 $excisedIds = [];
3874 $newTopSection = $this->currentAtomicSectionId();
3875 try {
3876 $excisedFnames = [];
3877 if ( $sectionId !== null ) {
3878 // Find the (last) section with the given $sectionId
3879 $pos = -1;
3880 foreach ( $this->trxAtomicLevels as $i => list( $asFname, $asId, $spId ) ) {
3881 if ( $asId === $sectionId ) {
3882 $pos = $i;
3883 }
3884 }
3885 if ( $pos < 0 ) {
3886 throw new DBUnexpectedError( $this, "Atomic section not found (for $fname)" );
3887 }
3888 // Remove all descendant sections and re-index the array
3889 $len = count( $this->trxAtomicLevels );
3890 for ( $i = $pos + 1; $i < $len; ++$i ) {
3891 $excisedFnames[] = $this->trxAtomicLevels[$i][0];
3892 $excisedIds[] = $this->trxAtomicLevels[$i][1];
3893 }
3894 $this->trxAtomicLevels = array_slice( $this->trxAtomicLevels, 0, $pos + 1 );
3895 $newTopSection = $this->currentAtomicSectionId();
3896 }
3897
3898 // Check if the current section matches $fname
3899 $pos = count( $this->trxAtomicLevels ) - 1;
3900 list( $savedFname, $savedSectionId, $savepointId ) = $this->trxAtomicLevels[$pos];
3901
3902 if ( $excisedFnames ) {
3903 $this->queryLogger->debug( "cancelAtomic: canceling level $pos ($savedFname) " .
3904 "and descendants " . implode( ', ', $excisedFnames ) );
3905 } else {
3906 $this->queryLogger->debug( "cancelAtomic: canceling level $pos ($savedFname)" );
3907 }
3908
3909 if ( $savedFname !== $fname ) {
3910 throw new DBUnexpectedError(
3911 $this,
3912 "Invalid atomic section ended (got $fname but expected $savedFname)"
3913 );
3914 }
3915
3916 // Remove the last section (no need to re-index the array)
3917 array_pop( $this->trxAtomicLevels );
3918 $excisedIds[] = $savedSectionId;
3919 $newTopSection = $this->currentAtomicSectionId();
3920
3921 if ( $savepointId !== null ) {
3922 // Rollback the transaction to the state just before this atomic section
3923 if ( $savepointId === self::$NOT_APPLICABLE ) {
3924 $this->rollback( $fname, self::FLUSHING_INTERNAL );
3925 // Note: rollback() will run trxSectionCancelCallbacks
3926 } else {
3927 $this->doRollbackToSavepoint( $savepointId, $fname );
3928 $this->trxStatus = self::STATUS_TRX_OK; // no exception; recovered
3929 $this->trxStatusIgnoredCause = null;
3930
3931 // Run trxSectionCancelCallbacks now.
3932 $this->runOnAtomicSectionCancelCallbacks( self::TRIGGER_CANCEL, $excisedIds );
3933 }
3934 } elseif ( $this->trxStatus > self::STATUS_TRX_ERROR ) {
3935 // Put the transaction into an error state if it's not already in one
3936 $this->trxStatus = self::STATUS_TRX_ERROR;
3937 $this->trxStatusCause = new DBUnexpectedError(
3938 $this,
3939 "Uncancelable atomic section canceled (got $fname)"
3940 );
3941 }
3942 } finally {
3943 // Fix up callbacks owned by the sections that were just cancelled.
3944 // All callbacks should have an owner that is present in trxAtomicLevels.
3945 $this->modifyCallbacksForCancel( $excisedIds, $newTopSection );
3946 }
3947
3948 $this->affectedRowCount = 0; // for the sake of consistency
3949 }
3950
3951 final public function doAtomicSection(
3952 $fname, callable $callback, $cancelable = self::ATOMIC_NOT_CANCELABLE
3953 ) {
3954 $sectionId = $this->startAtomic( $fname, $cancelable );
3955 try {
3956 $res = $callback( $this, $fname );
3957 } catch ( Exception $e ) {
3958 $this->cancelAtomic( $fname, $sectionId );
3959
3960 throw $e;
3961 }
3962 $this->endAtomic( $fname );
3963
3964 return $res;
3965 }
3966
3967 final public function begin( $fname = __METHOD__, $mode = self::TRANSACTION_EXPLICIT ) {
3968 static $modes = [ self::TRANSACTION_EXPLICIT, self::TRANSACTION_INTERNAL ];
3969 if ( !in_array( $mode, $modes, true ) ) {
3970 throw new DBUnexpectedError( $this, "$fname: invalid mode parameter '$mode'" );
3971 }
3972
3973 // Protect against mismatched atomic section, transaction nesting, and snapshot loss
3974 if ( $this->trxLevel() ) {
3975 if ( $this->trxAtomicLevels ) {
3976 $levels = $this->flatAtomicSectionList();
3977 $msg = "$fname: Got explicit BEGIN while atomic section(s) $levels are open";
3978 throw new DBUnexpectedError( $this, $msg );
3979 } elseif ( !$this->trxAutomatic ) {
3980 $msg = "$fname: Explicit transaction already active (from {$this->trxFname})";
3981 throw new DBUnexpectedError( $this, $msg );
3982 } else {
3983 $msg = "$fname: Implicit transaction already active (from {$this->trxFname})";
3984 throw new DBUnexpectedError( $this, $msg );
3985 }
3986 } elseif ( $this->getFlag( self::DBO_TRX ) && $mode !== self::TRANSACTION_INTERNAL ) {
3987 $msg = "$fname: Implicit transaction expected (DBO_TRX set)";
3988 throw new DBUnexpectedError( $this, $msg );
3989 }
3990
3991 $this->assertHasConnectionHandle();
3992
3993 $this->doBegin( $fname );
3994 $this->trxShortId = sprintf( '%06x', mt_rand( 0, 0xffffff ) );
3995 $this->trxStatus = self::STATUS_TRX_OK;
3996 $this->trxStatusIgnoredCause = null;
3997 $this->trxAtomicCounter = 0;
3998 $this->trxTimestamp = microtime( true );
3999 $this->trxFname = $fname;
4000 $this->trxDoneWrites = false;
4001 $this->trxAutomaticAtomic = false;
4002 $this->trxAtomicLevels = [];
4003 $this->trxWriteDuration = 0.0;
4004 $this->trxWriteQueryCount = 0;
4005 $this->trxWriteAffectedRows = 0;
4006 $this->trxWriteAdjDuration = 0.0;
4007 $this->trxWriteAdjQueryCount = 0;
4008 $this->trxWriteCallers = [];
4009 // First SELECT after BEGIN will establish the snapshot in REPEATABLE-READ.
4010 // Get an estimate of the replication lag before any such queries.
4011 $this->trxReplicaLag = null; // clear cached value first
4012 $this->trxReplicaLag = $this->getApproximateLagStatus()['lag'];
4013 // T147697: make explicitTrxActive() return true until begin() finishes. This way, no
4014 // caller will think its OK to muck around with the transaction just because startAtomic()
4015 // has not yet completed (e.g. setting trxAtomicLevels).
4016 $this->trxAutomatic = ( $mode === self::TRANSACTION_INTERNAL );
4017 }
4018
4019 /**
4020 * Issues the BEGIN command to the database server.
4021 *
4022 * @see Database::begin()
4023 * @param string $fname
4024 * @throws DBError
4025 */
4026 protected function doBegin( $fname ) {
4027 $this->query( 'BEGIN', $fname );
4028 }
4029
4030 final public function commit( $fname = __METHOD__, $flush = self::FLUSHING_ONE ) {
4031 static $modes = [ self::FLUSHING_ONE, self::FLUSHING_ALL_PEERS, self::FLUSHING_INTERNAL ];
4032 if ( !in_array( $flush, $modes, true ) ) {
4033 throw new DBUnexpectedError( $this, "$fname: invalid flush parameter '$flush'" );
4034 }
4035
4036 if ( $this->trxLevel() && $this->trxAtomicLevels ) {
4037 // There are still atomic sections open; this cannot be ignored
4038 $levels = $this->flatAtomicSectionList();
4039 throw new DBUnexpectedError(
4040 $this,
4041 "$fname: Got COMMIT while atomic sections $levels are still open"
4042 );
4043 }
4044
4045 if ( $flush === self::FLUSHING_INTERNAL || $flush === self::FLUSHING_ALL_PEERS ) {
4046 if ( !$this->trxLevel() ) {
4047 return; // nothing to do
4048 } elseif ( !$this->trxAutomatic ) {
4049 throw new DBUnexpectedError(
4050 $this,
4051 "$fname: Flushing an explicit transaction, getting out of sync"
4052 );
4053 }
4054 } elseif ( !$this->trxLevel() ) {
4055 $this->queryLogger->error(
4056 "$fname: No transaction to commit, something got out of sync" );
4057 return; // nothing to do
4058 } elseif ( $this->trxAutomatic ) {
4059 throw new DBUnexpectedError(
4060 $this,
4061 "$fname: Expected mass commit of all peer transactions (DBO_TRX set)"
4062 );
4063 }
4064
4065 $this->assertHasConnectionHandle();
4066
4067 $this->runOnTransactionPreCommitCallbacks();
4068
4069 $writeTime = $this->pendingWriteQueryDuration( self::ESTIMATE_DB_APPLY );
4070 $this->doCommit( $fname );
4071 $oldTrxShortId = $this->consumeTrxShortId();
4072 $this->trxStatus = self::STATUS_TRX_NONE;
4073
4074 if ( $this->trxDoneWrites ) {
4075 $this->lastWriteTime = microtime( true );
4076 $this->trxProfiler->transactionWritingOut(
4077 $this->server,
4078 $this->getDomainID(),
4079 $oldTrxShortId,
4080 $writeTime,
4081 $this->trxWriteAffectedRows
4082 );
4083 }
4084
4085 // With FLUSHING_ALL_PEERS, callbacks will be explicitly run later
4086 if ( $flush !== self::FLUSHING_ALL_PEERS ) {
4087 $this->runOnTransactionIdleCallbacks( self::TRIGGER_COMMIT );
4088 $this->runTransactionListenerCallbacks( self::TRIGGER_COMMIT );
4089 }
4090 }
4091
4092 /**
4093 * Issues the COMMIT command to the database server.
4094 *
4095 * @see Database::commit()
4096 * @param string $fname
4097 * @throws DBError
4098 */
4099 protected function doCommit( $fname ) {
4100 if ( $this->trxLevel() ) {
4101 $this->query( 'COMMIT', $fname );
4102 }
4103 }
4104
4105 final public function rollback( $fname = __METHOD__, $flush = self::FLUSHING_ONE ) {
4106 $trxActive = $this->trxLevel();
4107
4108 if ( $flush !== self::FLUSHING_INTERNAL
4109 && $flush !== self::FLUSHING_ALL_PEERS
4110 && $this->getFlag( self::DBO_TRX )
4111 ) {
4112 throw new DBUnexpectedError(
4113 $this,
4114 "$fname: Expected mass rollback of all peer transactions (DBO_TRX set)"
4115 );
4116 }
4117
4118 if ( $trxActive ) {
4119 $this->assertHasConnectionHandle();
4120
4121 $this->doRollback( $fname );
4122 $oldTrxShortId = $this->consumeTrxShortId();
4123 $this->trxStatus = self::STATUS_TRX_NONE;
4124 $this->trxAtomicLevels = [];
4125 // Estimate the RTT via a query now that trxStatus is OK
4126 $writeTime = $this->pingAndCalculateLastTrxApplyTime();
4127
4128 if ( $this->trxDoneWrites ) {
4129 $this->trxProfiler->transactionWritingOut(
4130 $this->server,
4131 $this->getDomainID(),
4132 $oldTrxShortId,
4133 $writeTime,
4134 $this->trxWriteAffectedRows
4135 );
4136 }
4137 }
4138
4139 // Clear any commit-dependant callbacks. They might even be present
4140 // only due to transaction rounds, with no SQL transaction being active
4141 $this->trxIdleCallbacks = [];
4142 $this->trxPreCommitCallbacks = [];
4143
4144 // With FLUSHING_ALL_PEERS, callbacks will be explicitly run later
4145 if ( $trxActive && $flush !== self::FLUSHING_ALL_PEERS ) {
4146 try {
4147 $this->runOnTransactionIdleCallbacks( self::TRIGGER_ROLLBACK );
4148 } catch ( Exception $e ) {
4149 // already logged; finish and let LoadBalancer move on during mass-rollback
4150 }
4151 try {
4152 $this->runTransactionListenerCallbacks( self::TRIGGER_ROLLBACK );
4153 } catch ( Exception $e ) {
4154 // already logged; let LoadBalancer move on during mass-rollback
4155 }
4156
4157 $this->affectedRowCount = 0; // for the sake of consistency
4158 }
4159 }
4160
4161 /**
4162 * Issues the ROLLBACK command to the database server.
4163 *
4164 * @see Database::rollback()
4165 * @param string $fname
4166 * @throws DBError
4167 */
4168 protected function doRollback( $fname ) {
4169 if ( $this->trxLevel() ) {
4170 # Disconnects cause rollback anyway, so ignore those errors
4171 $ignoreErrors = true;
4172 $this->query( 'ROLLBACK', $fname, $ignoreErrors );
4173 }
4174 }
4175
4176 public function flushSnapshot( $fname = __METHOD__, $flush = self::FLUSHING_ONE ) {
4177 if ( $this->explicitTrxActive() ) {
4178 // Committing this transaction would break callers that assume it is still open
4179 throw new DBUnexpectedError(
4180 $this,
4181 "$fname: Cannot flush snapshot; " .
4182 "explicit transaction '{$this->trxFname}' is still open"
4183 );
4184 } elseif ( $this->writesOrCallbacksPending() ) {
4185 // This only flushes transactions to clear snapshots, not to write data
4186 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
4187 throw new DBUnexpectedError(
4188 $this,
4189 "$fname: Cannot flush snapshot; " .
4190 "writes from transaction {$this->trxFname} are still pending ($fnames)"
4191 );
4192 } elseif (
4193 $this->trxLevel() &&
4194 $this->getTransactionRoundId() &&
4195 $flush !== self::FLUSHING_INTERNAL &&
4196 $flush !== self::FLUSHING_ALL_PEERS
4197 ) {
4198 $this->queryLogger->warning(
4199 "$fname: Expected mass snapshot flush of all peer transactions " .
4200 "in the explicit transactions round '{$this->getTransactionRoundId()}'",
4201 [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
4202 );
4203 }
4204
4205 $this->commit( $fname, self::FLUSHING_INTERNAL );
4206 }
4207
4208 public function explicitTrxActive() {
4209 return $this->trxLevel() && ( $this->trxAtomicLevels || !$this->trxAutomatic );
4210 }
4211
4212 public function duplicateTableStructure(
4213 $oldName, $newName, $temporary = false, $fname = __METHOD__
4214 ) {
4215 throw new RuntimeException( __METHOD__ . ' is not implemented in descendant class' );
4216 }
4217
4218 public function listTables( $prefix = null, $fname = __METHOD__ ) {
4219 throw new RuntimeException( __METHOD__ . ' is not implemented in descendant class' );
4220 }
4221
4222 public function listViews( $prefix = null, $fname = __METHOD__ ) {
4223 throw new RuntimeException( __METHOD__ . ' is not implemented in descendant class' );
4224 }
4225
4226 public function timestamp( $ts = 0 ) {
4227 $t = new ConvertibleTimestamp( $ts );
4228 // Let errors bubble up to avoid putting garbage in the DB
4229 return $t->getTimestamp( TS_MW );
4230 }
4231
4232 public function timestampOrNull( $ts = null ) {
4233 if ( is_null( $ts ) ) {
4234 return null;
4235 } else {
4236 return $this->timestamp( $ts );
4237 }
4238 }
4239
4240 public function affectedRows() {
4241 return ( $this->affectedRowCount === null )
4242 ? $this->fetchAffectedRowCount() // default to driver value
4243 : $this->affectedRowCount;
4244 }
4245
4246 /**
4247 * @return int Number of retrieved rows according to the driver
4248 */
4249 abstract protected function fetchAffectedRowCount();
4250
4251 /**
4252 * Take a query result and wrap it in an iterable result wrapper if necessary.
4253 * Booleans are passed through as-is to indicate success/failure of write queries.
4254 *
4255 * Once upon a time, Database::query() returned a bare MySQL result
4256 * resource, and it was necessary to call this function to convert it to
4257 * a wrapper. Nowadays, raw database objects are never exposed to external
4258 * callers, so this is unnecessary in external code.
4259 *
4260 * @param bool|IResultWrapper|resource $result
4261 * @return bool|IResultWrapper
4262 */
4263 protected function resultObject( $result ) {
4264 if ( !$result ) {
4265 return false; // failed query
4266 } elseif ( $result instanceof IResultWrapper ) {
4267 return $result;
4268 } elseif ( $result === true ) {
4269 return $result; // succesful write query
4270 } else {
4271 return new ResultWrapper( $this, $result );
4272 }
4273 }
4274
4275 public function ping( &$rtt = null ) {
4276 // Avoid hitting the server if it was hit recently
4277 if ( $this->isOpen() && ( microtime( true ) - $this->lastPing ) < self::$PING_TTL ) {
4278 if ( !func_num_args() || $this->lastRoundTripEstimate > 0 ) {
4279 $rtt = $this->lastRoundTripEstimate;
4280 return true; // don't care about $rtt
4281 }
4282 }
4283
4284 // This will reconnect if possible or return false if not
4285 $this->clearFlag( self::DBO_TRX, self::REMEMBER_PRIOR );
4286 $ok = ( $this->query( self::$PING_QUERY, __METHOD__, true ) !== false );
4287 $this->restoreFlags( self::RESTORE_PRIOR );
4288
4289 if ( $ok ) {
4290 $rtt = $this->lastRoundTripEstimate;
4291 }
4292
4293 return $ok;
4294 }
4295
4296 /**
4297 * Close any existing (dead) database connection and open a new connection
4298 *
4299 * @param string $fname
4300 * @return bool True if new connection is opened successfully, false if error
4301 */
4302 protected function replaceLostConnection( $fname ) {
4303 $this->closeConnection();
4304 $this->conn = null;
4305
4306 $this->handleSessionLossPreconnect();
4307
4308 try {
4309 $this->open(
4310 $this->server,
4311 $this->user,
4312 $this->password,
4313 $this->currentDomain->getDatabase(),
4314 $this->currentDomain->getSchema(),
4315 $this->tablePrefix()
4316 );
4317 $this->lastPing = microtime( true );
4318 $ok = true;
4319
4320 $this->connLogger->warning(
4321 $fname . ': lost connection to {dbserver}; reconnected',
4322 [
4323 'dbserver' => $this->getServer(),
4324 'trace' => ( new RuntimeException() )->getTraceAsString()
4325 ]
4326 );
4327 } catch ( DBConnectionError $e ) {
4328 $ok = false;
4329
4330 $this->connLogger->error(
4331 $fname . ': lost connection to {dbserver} permanently',
4332 [ 'dbserver' => $this->getServer() ]
4333 );
4334 }
4335
4336 $this->handleSessionLossPostconnect();
4337
4338 return $ok;
4339 }
4340
4341 public function getSessionLagStatus() {
4342 return $this->getRecordedTransactionLagStatus() ?: $this->getApproximateLagStatus();
4343 }
4344
4345 /**
4346 * Get the replica DB lag when the current transaction started
4347 *
4348 * This is useful when transactions might use snapshot isolation
4349 * (e.g. REPEATABLE-READ in innodb), so the "real" lag of that data
4350 * is this lag plus transaction duration. If they don't, it is still
4351 * safe to be pessimistic. This returns null if there is no transaction.
4352 *
4353 * This returns null if the lag status for this transaction was not yet recorded.
4354 *
4355 * @return array|null ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)
4356 * @since 1.27
4357 */
4358 final protected function getRecordedTransactionLagStatus() {
4359 return ( $this->trxLevel() && $this->trxReplicaLag !== null )
4360 ? [ 'lag' => $this->trxReplicaLag, 'since' => $this->trxTimestamp() ]
4361 : null;
4362 }
4363
4364 /**
4365 * Get a replica DB lag estimate for this server
4366 *
4367 * @return array ('lag': seconds or false on error, 'since': UNIX timestamp of estimate)
4368 * @since 1.27
4369 */
4370 protected function getApproximateLagStatus() {
4371 return [
4372 'lag' => $this->getLBInfo( 'replica' ) ? $this->getLag() : 0,
4373 'since' => microtime( true )
4374 ];
4375 }
4376
4377 /**
4378 * Merge the result of getSessionLagStatus() for several DBs
4379 * using the most pessimistic values to estimate the lag of
4380 * any data derived from them in combination
4381 *
4382 * This is information is useful for caching modules
4383 *
4384 * @see WANObjectCache::set()
4385 * @see WANObjectCache::getWithSetCallback()
4386 *
4387 * @param IDatabase $db1
4388 * @param IDatabase|null $db2 [optional]
4389 * @return array Map of values:
4390 * - lag: highest lag of any of the DBs or false on error (e.g. replication stopped)
4391 * - since: oldest UNIX timestamp of any of the DB lag estimates
4392 * - pending: whether any of the DBs have uncommitted changes
4393 * @throws DBError
4394 * @since 1.27
4395 */
4396 public static function getCacheSetOptions( IDatabase $db1, IDatabase $db2 = null ) {
4397 $res = [ 'lag' => 0, 'since' => INF, 'pending' => false ];
4398 foreach ( func_get_args() as $db ) {
4399 /** @var IDatabase $db */
4400 $status = $db->getSessionLagStatus();
4401 if ( $status['lag'] === false ) {
4402 $res['lag'] = false;
4403 } elseif ( $res['lag'] !== false ) {
4404 $res['lag'] = max( $res['lag'], $status['lag'] );
4405 }
4406 $res['since'] = min( $res['since'], $status['since'] );
4407 $res['pending'] = $res['pending'] ?: $db->writesPending();
4408 }
4409
4410 return $res;
4411 }
4412
4413 public function getLag() {
4414 if ( $this->getLBInfo( 'master' ) ) {
4415 return 0; // this is the master
4416 } elseif ( $this->getLBInfo( 'is static' ) ) {
4417 return 0; // static dataset
4418 }
4419
4420 return $this->doGetLag();
4421 }
4422
4423 protected function doGetLag() {
4424 return 0;
4425 }
4426
4427 public function maxListLen() {
4428 return 0;
4429 }
4430
4431 public function encodeBlob( $b ) {
4432 return $b;
4433 }
4434
4435 public function decodeBlob( $b ) {
4436 if ( $b instanceof Blob ) {
4437 $b = $b->fetch();
4438 }
4439 return $b;
4440 }
4441
4442 public function setSessionOptions( array $options ) {
4443 }
4444
4445 public function sourceFile(
4446 $filename,
4447 callable $lineCallback = null,
4448 callable $resultCallback = null,
4449 $fname = false,
4450 callable $inputCallback = null
4451 ) {
4452 AtEase::suppressWarnings();
4453 $fp = fopen( $filename, 'r' );
4454 AtEase::restoreWarnings();
4455
4456 if ( $fp === false ) {
4457 throw new RuntimeException( "Could not open \"{$filename}\"" );
4458 }
4459
4460 if ( !$fname ) {
4461 $fname = __METHOD__ . "( $filename )";
4462 }
4463
4464 try {
4465 $error = $this->sourceStream(
4466 $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
4467 } catch ( Exception $e ) {
4468 fclose( $fp );
4469 throw $e;
4470 }
4471
4472 fclose( $fp );
4473
4474 return $error;
4475 }
4476
4477 public function setSchemaVars( $vars ) {
4478 $this->schemaVars = $vars;
4479 }
4480
4481 public function sourceStream(
4482 $fp,
4483 callable $lineCallback = null,
4484 callable $resultCallback = null,
4485 $fname = __METHOD__,
4486 callable $inputCallback = null
4487 ) {
4488 $delimiterReset = new ScopedCallback(
4489 function ( $delimiter ) {
4490 $this->delimiter = $delimiter;
4491 },
4492 [ $this->delimiter ]
4493 );
4494 $cmd = '';
4495
4496 while ( !feof( $fp ) ) {
4497 if ( $lineCallback ) {
4498 call_user_func( $lineCallback );
4499 }
4500
4501 $line = trim( fgets( $fp ) );
4502
4503 if ( $line == '' ) {
4504 continue;
4505 }
4506
4507 if ( $line[0] == '-' && $line[1] == '-' ) {
4508 continue;
4509 }
4510
4511 if ( $cmd != '' ) {
4512 $cmd .= ' ';
4513 }
4514
4515 $done = $this->streamStatementEnd( $cmd, $line );
4516
4517 $cmd .= "$line\n";
4518
4519 if ( $done || feof( $fp ) ) {
4520 $cmd = $this->replaceVars( $cmd );
4521
4522 if ( $inputCallback ) {
4523 $callbackResult = $inputCallback( $cmd );
4524
4525 if ( is_string( $callbackResult ) || !$callbackResult ) {
4526 $cmd = $callbackResult;
4527 }
4528 }
4529
4530 if ( $cmd ) {
4531 $res = $this->query( $cmd, $fname );
4532
4533 if ( $resultCallback ) {
4534 $resultCallback( $res, $this );
4535 }
4536
4537 if ( $res === false ) {
4538 $err = $this->lastError();
4539
4540 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
4541 }
4542 }
4543 $cmd = '';
4544 }
4545 }
4546
4547 ScopedCallback::consume( $delimiterReset );
4548 return true;
4549 }
4550
4551 /**
4552 * Called by sourceStream() to check if we've reached a statement end
4553 *
4554 * @param string &$sql SQL assembled so far
4555 * @param string &$newLine New line about to be added to $sql
4556 * @return bool Whether $newLine contains end of the statement
4557 */
4558 public function streamStatementEnd( &$sql, &$newLine ) {
4559 if ( $this->delimiter ) {
4560 $prev = $newLine;
4561 $newLine = preg_replace(
4562 '/' . preg_quote( $this->delimiter, '/' ) . '$/', '', $newLine );
4563 if ( $newLine != $prev ) {
4564 return true;
4565 }
4566 }
4567
4568 return false;
4569 }
4570
4571 /**
4572 * Database independent variable replacement. Replaces a set of variables
4573 * in an SQL statement with their contents as given by $this->getSchemaVars().
4574 *
4575 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
4576 *
4577 * - '{$var}' should be used for text and is passed through the database's
4578 * addQuotes method.
4579 * - `{$var}` should be used for identifiers (e.g. table and database names).
4580 * It is passed through the database's addIdentifierQuotes method which
4581 * can be overridden if the database uses something other than backticks.
4582 * - / *_* / or / *$wgDBprefix* / passes the name that follows through the
4583 * database's tableName method.
4584 * - / *i* / passes the name that follows through the database's indexName method.
4585 * - In all other cases, / *$var* / is left unencoded. Except for table options,
4586 * its use should be avoided. In 1.24 and older, string encoding was applied.
4587 *
4588 * @param string $ins SQL statement to replace variables in
4589 * @return string The new SQL statement with variables replaced
4590 */
4591 protected function replaceVars( $ins ) {
4592 $vars = $this->getSchemaVars();
4593 return preg_replace_callback(
4594 '!
4595 /\* (\$wgDBprefix|[_i]) \*/ (\w*) | # 1-2. tableName, indexName
4596 \'\{\$ (\w+) }\' | # 3. addQuotes
4597 `\{\$ (\w+) }` | # 4. addIdentifierQuotes
4598 /\*\$ (\w+) \*/ # 5. leave unencoded
4599 !x',
4600 function ( $m ) use ( $vars ) {
4601 // Note: Because of <https://bugs.php.net/bug.php?id=51881>,
4602 // check for both nonexistent keys *and* the empty string.
4603 if ( isset( $m[1] ) && $m[1] !== '' ) {
4604 if ( $m[1] === 'i' ) {
4605 return $this->indexName( $m[2] );
4606 } else {
4607 return $this->tableName( $m[2] );
4608 }
4609 } elseif ( isset( $m[3] ) && $m[3] !== '' && array_key_exists( $m[3], $vars ) ) {
4610 return $this->addQuotes( $vars[$m[3]] );
4611 } elseif ( isset( $m[4] ) && $m[4] !== '' && array_key_exists( $m[4], $vars ) ) {
4612 return $this->addIdentifierQuotes( $vars[$m[4]] );
4613 } elseif ( isset( $m[5] ) && $m[5] !== '' && array_key_exists( $m[5], $vars ) ) {
4614 return $vars[$m[5]];
4615 } else {
4616 return $m[0];
4617 }
4618 },
4619 $ins
4620 );
4621 }
4622
4623 /**
4624 * Get schema variables. If none have been set via setSchemaVars(), then
4625 * use some defaults from the current object.
4626 *
4627 * @return array
4628 */
4629 protected function getSchemaVars() {
4630 if ( $this->schemaVars ) {
4631 return $this->schemaVars;
4632 } else {
4633 return $this->getDefaultSchemaVars();
4634 }
4635 }
4636
4637 /**
4638 * Get schema variables to use if none have been set via setSchemaVars().
4639 *
4640 * Override this in derived classes to provide variables for tables.sql
4641 * and SQL patch files.
4642 *
4643 * @return array
4644 */
4645 protected function getDefaultSchemaVars() {
4646 return [];
4647 }
4648
4649 public function lockIsFree( $lockName, $method ) {
4650 // RDBMs methods for checking named locks may or may not count this thread itself.
4651 // In MySQL, IS_FREE_LOCK() returns 0 if the thread already has the lock. This is
4652 // the behavior choosen by the interface for this method.
4653 return !isset( $this->sessionNamedLocks[$lockName] );
4654 }
4655
4656 public function lock( $lockName, $method, $timeout = 5 ) {
4657 $this->sessionNamedLocks[$lockName] = 1;
4658
4659 return true;
4660 }
4661
4662 public function unlock( $lockName, $method ) {
4663 unset( $this->sessionNamedLocks[$lockName] );
4664
4665 return true;
4666 }
4667
4668 public function getScopedLockAndFlush( $lockKey, $fname, $timeout ) {
4669 if ( $this->writesOrCallbacksPending() ) {
4670 // This only flushes transactions to clear snapshots, not to write data
4671 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
4672 throw new DBUnexpectedError(
4673 $this,
4674 "$fname: Cannot flush pre-lock snapshot; " .
4675 "writes from transaction {$this->trxFname} are still pending ($fnames)"
4676 );
4677 }
4678
4679 if ( !$this->lock( $lockKey, $fname, $timeout ) ) {
4680 return null;
4681 }
4682
4683 $unlocker = new ScopedCallback( function () use ( $lockKey, $fname ) {
4684 if ( $this->trxLevel() ) {
4685 // There is a good chance an exception was thrown, causing any early return
4686 // from the caller. Let any error handler get a chance to issue rollback().
4687 // If there isn't one, let the error bubble up and trigger server-side rollback.
4688 $this->onTransactionResolution(
4689 function () use ( $lockKey, $fname ) {
4690 $this->unlock( $lockKey, $fname );
4691 },
4692 $fname
4693 );
4694 } else {
4695 $this->unlock( $lockKey, $fname );
4696 }
4697 } );
4698
4699 $this->commit( $fname, self::FLUSHING_INTERNAL );
4700
4701 return $unlocker;
4702 }
4703
4704 public function namedLocksEnqueue() {
4705 return false;
4706 }
4707
4708 public function tableLocksHaveTransactionScope() {
4709 return true;
4710 }
4711
4712 final public function lockTables( array $read, array $write, $method ) {
4713 if ( $this->writesOrCallbacksPending() ) {
4714 throw new DBUnexpectedError( $this, "Transaction writes or callbacks still pending" );
4715 }
4716
4717 if ( $this->tableLocksHaveTransactionScope() ) {
4718 $this->startAtomic( $method );
4719 }
4720
4721 return $this->doLockTables( $read, $write, $method );
4722 }
4723
4724 /**
4725 * Helper function for lockTables() that handles the actual table locking
4726 *
4727 * @param array $read Array of tables to lock for read access
4728 * @param array $write Array of tables to lock for write access
4729 * @param string $method Name of caller
4730 * @return true
4731 */
4732 protected function doLockTables( array $read, array $write, $method ) {
4733 return true;
4734 }
4735
4736 final public function unlockTables( $method ) {
4737 if ( $this->tableLocksHaveTransactionScope() ) {
4738 $this->endAtomic( $method );
4739
4740 return true; // locks released on COMMIT/ROLLBACK
4741 }
4742
4743 return $this->doUnlockTables( $method );
4744 }
4745
4746 /**
4747 * Helper function for unlockTables() that handles the actual table unlocking
4748 *
4749 * @param string $method Name of caller
4750 * @return true
4751 */
4752 protected function doUnlockTables( $method ) {
4753 return true;
4754 }
4755
4756 /**
4757 * Delete a table
4758 * @param string $tableName
4759 * @param string $fName
4760 * @return bool|IResultWrapper
4761 * @since 1.18
4762 */
4763 public function dropTable( $tableName, $fName = __METHOD__ ) {
4764 if ( !$this->tableExists( $tableName, $fName ) ) {
4765 return false;
4766 }
4767 $sql = "DROP TABLE " . $this->tableName( $tableName ) . " CASCADE";
4768
4769 return $this->query( $sql, $fName );
4770 }
4771
4772 public function getInfinity() {
4773 return 'infinity';
4774 }
4775
4776 public function encodeExpiry( $expiry ) {
4777 return ( $expiry == '' || $expiry == 'infinity' || $expiry == $this->getInfinity() )
4778 ? $this->getInfinity()
4779 : $this->timestamp( $expiry );
4780 }
4781
4782 public function decodeExpiry( $expiry, $format = TS_MW ) {
4783 if ( $expiry == '' || $expiry == 'infinity' || $expiry == $this->getInfinity() ) {
4784 return 'infinity';
4785 }
4786
4787 return ConvertibleTimestamp::convert( $format, $expiry );
4788 }
4789
4790 public function setBigSelects( $value = true ) {
4791 // no-op
4792 }
4793
4794 public function isReadOnly() {
4795 return ( $this->getReadOnlyReason() !== false );
4796 }
4797
4798 /**
4799 * @return string|bool Reason this DB is read-only or false if it is not
4800 */
4801 protected function getReadOnlyReason() {
4802 $reason = $this->getLBInfo( 'readOnlyReason' );
4803 if ( is_string( $reason ) ) {
4804 return $reason;
4805 } elseif ( $this->getLBInfo( 'replica' ) ) {
4806 return "Server is configured in the role of a read-only replica database.";
4807 }
4808
4809 return false;
4810 }
4811
4812 public function setTableAliases( array $aliases ) {
4813 $this->tableAliases = $aliases;
4814 }
4815
4816 public function setIndexAliases( array $aliases ) {
4817 $this->indexAliases = $aliases;
4818 }
4819
4820 /**
4821 * @param int $field
4822 * @param int $flags
4823 * @return bool
4824 */
4825 protected function hasFlags( $field, $flags ) {
4826 return ( ( $field & $flags ) === $flags );
4827 }
4828
4829 /**
4830 * Get the underlying binding connection handle
4831 *
4832 * Makes sure the connection resource is set (disconnects and ping() failure can unset it).
4833 * This catches broken callers than catch and ignore disconnection exceptions.
4834 * Unlike checking isOpen(), this is safe to call inside of open().
4835 *
4836 * @return mixed
4837 * @throws DBUnexpectedError
4838 * @since 1.26
4839 */
4840 protected function getBindingHandle() {
4841 if ( !$this->conn ) {
4842 throw new DBUnexpectedError(
4843 $this,
4844 'DB connection was already closed or the connection dropped'
4845 );
4846 }
4847
4848 return $this->conn;
4849 }
4850
4851 public function __toString() {
4852 // spl_object_id is PHP >= 7.2
4853 $id = function_exists( 'spl_object_id' )
4854 ? spl_object_id( $this )
4855 : spl_object_hash( $this );
4856
4857 $description = $this->getType() . ' object #' . $id;
4858 if ( is_resource( $this->conn ) ) {
4859 $description .= ' (' . (string)$this->conn . ')'; // "resource id #<ID>"
4860 } elseif ( is_object( $this->conn ) ) {
4861 // spl_object_id is PHP >= 7.2
4862 $handleId = function_exists( 'spl_object_id' )
4863 ? spl_object_id( $this->conn )
4864 : spl_object_hash( $this->conn );
4865 $description .= " (handle id #$handleId)";
4866 }
4867
4868 return $description;
4869 }
4870
4871 /**
4872 * Make sure that copies do not share the same client binding handle
4873 * @throws DBConnectionError
4874 */
4875 public function __clone() {
4876 $this->connLogger->warning(
4877 "Cloning " . static::class . " is not recommended; forking connection",
4878 [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
4879 );
4880
4881 if ( $this->isOpen() ) {
4882 // Open a new connection resource without messing with the old one
4883 $this->conn = null;
4884 $this->trxEndCallbacks = []; // don't copy
4885 $this->trxSectionCancelCallbacks = []; // don't copy
4886 $this->handleSessionLossPreconnect(); // no trx or locks anymore
4887 $this->open(
4888 $this->server,
4889 $this->user,
4890 $this->password,
4891 $this->currentDomain->getDatabase(),
4892 $this->currentDomain->getSchema(),
4893 $this->tablePrefix()
4894 );
4895 $this->lastPing = microtime( true );
4896 }
4897 }
4898
4899 /**
4900 * Called by serialize. Throw an exception when DB connection is serialized.
4901 * This causes problems on some database engines because the connection is
4902 * not restored on unserialize.
4903 */
4904 public function __sleep() {
4905 throw new RuntimeException( 'Database serialization may cause problems, since ' .
4906 'the connection is not restored on wakeup' );
4907 }
4908
4909 /**
4910 * Run a few simple sanity checks and close dangling connections
4911 */
4912 public function __destruct() {
4913 if ( $this->trxLevel() && $this->trxDoneWrites ) {
4914 trigger_error( "Uncommitted DB writes (transaction from {$this->trxFname})" );
4915 }
4916
4917 $danglingWriters = $this->pendingWriteAndCallbackCallers();
4918 if ( $danglingWriters ) {
4919 $fnames = implode( ', ', $danglingWriters );
4920 trigger_error( "DB transaction writes or callbacks still pending ($fnames)" );
4921 }
4922
4923 if ( $this->conn ) {
4924 // Avoid connection leaks for sanity. Normally, resources close at script completion.
4925 // The connection might already be closed in zend/hhvm by now, so suppress warnings.
4926 AtEase::suppressWarnings();
4927 $this->closeConnection();
4928 AtEase::restoreWarnings();
4929 $this->conn = null;
4930 }
4931 }
4932 }
4933
4934 /**
4935 * @deprecated since 1.28
4936 */
4937 class_alias( Database::class, 'DatabaseBase' );
4938
4939 /**
4940 * @deprecated since 1.29
4941 */
4942 class_alias( Database::class, 'Database' );
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