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Merge "phpunit: Add more info to LocalSettings.php error in MediaWikiIntegrationTestCase"
[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 BagOStuff APC cache */
51 protected $srvCache;
52 /** @var LoggerInterface */
53 protected $connLogger;
54 /** @var LoggerInterface */
55 protected $queryLogger;
56 /** @var callable Error logging callback */
57 protected $errorLogger;
58 /** @var callable Deprecation logging callback */
59 protected $deprecationLogger;
60 /** @var callable|null */
61 protected $profiler;
62 /** @var TransactionProfiler */
63 protected $trxProfiler;
64
65 /** @var DatabaseDomain */
66 protected $currentDomain;
67
68 /** @var object|resource|null Database connection */
69 protected $conn;
70
71 /** @var IDatabase|null Lazy handle to the master DB this server replicates from */
72 private $lazyMasterHandle;
73
74 /** @var string Server that this instance is currently connected to */
75 protected $server;
76 /** @var string User that this instance is currently connected under the name of */
77 protected $user;
78 /** @var string Password used to establish the current connection */
79 protected $password;
80 /** @var bool Whether this PHP instance is for a CLI script */
81 protected $cliMode;
82 /** @var string Agent name for query profiling */
83 protected $agent;
84 /** @var array Parameters used by initConnection() to establish a connection */
85 protected $connectionParams;
86 /** @var string[]|int[]|float[] SQL variables values to use for all new connections */
87 protected $connectionVariables;
88 /** @var int Row batch size to use for emulated INSERT SELECT queries */
89 protected $nonNativeInsertSelectBatchSize;
90
91 /** @var int Current bit field of class DBO_* constants */
92 protected $flags;
93 /** @var array Current LoadBalancer tracking information */
94 protected $lbInfo = [];
95 /** @var string Current SQL query delimiter */
96 protected $delimiter = ';';
97 /** @var array[] Current map of (table => (dbname, schema, prefix) map) */
98 protected $tableAliases = [];
99 /** @var string[] Current map of (index alias => index) */
100 protected $indexAliases = [];
101 /** @var array|null Current variables use for schema element placeholders */
102 protected $schemaVars;
103
104 /** @var string|bool|null Stashed value of html_errors INI setting */
105 private $htmlErrors;
106 /** @var int[] Prior flags member variable values */
107 private $priorFlags = [];
108
109 /** @var array Map of (name => 1) for locks obtained via lock() */
110 protected $sessionNamedLocks = [];
111 /** @var array Map of (table name => 1) for TEMPORARY tables */
112 protected $sessionTempTables = [];
113
114 /** @var string ID of the active transaction or the empty string otherwise */
115 private $trxShortId = '';
116 /** @var int Transaction status */
117 private $trxStatus = self::STATUS_TRX_NONE;
118 /** @var Exception|null The last error that caused the status to become STATUS_TRX_ERROR */
119 private $trxStatusCause;
120 /** @var array|null Error details of the last statement-only rollback */
121 private $trxStatusIgnoredCause;
122 /** @var float|null UNIX timestamp at the time of BEGIN for the last transaction */
123 private $trxTimestamp = null;
124 /** @var float Replication lag estimate at the time of BEGIN for the last transaction */
125 private $trxReplicaLag = null;
126 /** @var string Name of the function that start the last transaction */
127 private $trxFname = null;
128 /** @var bool Whether possible write queries were done in the last transaction started */
129 private $trxDoneWrites = false;
130 /** @var bool Whether the current transaction was started implicitly due to DBO_TRX */
131 private $trxAutomatic = false;
132 /** @var int Counter for atomic savepoint identifiers (reset with each transaction) */
133 private $trxAtomicCounter = 0;
134 /** @var array List of (name, unique ID, savepoint ID) for each active atomic section level */
135 private $trxAtomicLevels = [];
136 /** @var bool Whether the current transaction was started implicitly by startAtomic() */
137 private $trxAutomaticAtomic = false;
138 /** @var string[] Write query callers of the current transaction */
139 private $trxWriteCallers = [];
140 /** @var float Seconds spent in write queries for the current transaction */
141 private $trxWriteDuration = 0.0;
142 /** @var int Number of write queries for the current transaction */
143 private $trxWriteQueryCount = 0;
144 /** @var int Number of rows affected by write queries for the current transaction */
145 private $trxWriteAffectedRows = 0;
146 /** @var float Like trxWriteQueryCount but excludes lock-bound, easy to replicate, queries */
147 private $trxWriteAdjDuration = 0.0;
148 /** @var int Number of write queries counted in trxWriteAdjDuration */
149 private $trxWriteAdjQueryCount = 0;
150 /** @var array[] List of (callable, method name, atomic section id) */
151 private $trxIdleCallbacks = [];
152 /** @var array[] List of (callable, method name, atomic section id) */
153 private $trxPreCommitCallbacks = [];
154 /** @var array[] List of (callable, method name, atomic section id) */
155 private $trxEndCallbacks = [];
156 /** @var array[] List of (callable, method name, atomic section id) */
157 private $trxSectionCancelCallbacks = [];
158 /** @var callable[] Map of (name => callable) */
159 private $trxRecurringCallbacks = [];
160 /** @var bool Whether to suppress triggering of transaction end callbacks */
161 private $trxEndCallbacksSuppressed = false;
162
163 /** @var integer|null Rows affected by the last query to query() or its CRUD wrappers */
164 protected $affectedRowCount;
165
166 /** @var float UNIX timestamp */
167 private $lastPing = 0.0;
168 /** @var string The last SQL query attempted */
169 private $lastQuery = '';
170 /** @var float|bool UNIX timestamp of last write query */
171 private $lastWriteTime = false;
172 /** @var string|bool */
173 private $lastPhpError = false;
174 /** @var float Query rount trip time estimate */
175 private $lastRoundTripEstimate = 0.0;
176
177 /** @var string Lock granularity is on the level of the entire database */
178 const ATTR_DB_LEVEL_LOCKING = 'db-level-locking';
179 /** @var string The SCHEMA keyword refers to a grouping of tables in a database */
180 const ATTR_SCHEMAS_AS_TABLE_GROUPS = 'supports-schemas';
181
182 /** @var int New Database instance will not be connected yet when returned */
183 const NEW_UNCONNECTED = 0;
184 /** @var int New Database instance will already be connected when returned */
185 const NEW_CONNECTED = 1;
186
187 /** @var int Transaction is in a error state requiring a full or savepoint rollback */
188 const STATUS_TRX_ERROR = 1;
189 /** @var int Transaction is active and in a normal state */
190 const STATUS_TRX_OK = 2;
191 /** @var int No transaction is active */
192 const STATUS_TRX_NONE = 3;
193
194 /** @var string Idiom used when a cancelable atomic section started the transaction */
195 private static $NOT_APPLICABLE = 'n/a';
196 /** @var string Prefix to the atomic section counter used to make savepoint IDs */
197 private static $SAVEPOINT_PREFIX = 'wikimedia_rdbms_atomic';
198
199 /** @var int Writes to this temporary table do not affect lastDoneWrites() */
200 private static $TEMP_NORMAL = 1;
201 /** @var int Writes to this temporary table effect lastDoneWrites() */
202 private static $TEMP_PSEUDO_PERMANENT = 2;
203
204 /** @var int Number of times to re-try an operation in case of deadlock */
205 private static $DEADLOCK_TRIES = 4;
206 /** @var int Minimum time to wait before retry, in microseconds */
207 private static $DEADLOCK_DELAY_MIN = 500000;
208 /** @var int Maximum time to wait before retry */
209 private static $DEADLOCK_DELAY_MAX = 1500000;
210
211 /** @var int How long before it is worth doing a dummy query to test the connection */
212 private static $PING_TTL = 1.0;
213 /** @var string Dummy SQL query */
214 private static $PING_QUERY = 'SELECT 1 AS ping';
215
216 /** @var float Guess of how many seconds it takes to replicate a small insert */
217 private static $TINY_WRITE_SEC = 0.010;
218 /** @var float Consider a write slow if it took more than this many seconds */
219 private static $SLOW_WRITE_SEC = 0.500;
220 /** @var float Assume an insert of this many rows or less should be fast to replicate */
221 private static $SMALL_WRITE_ROWS = 100;
222
223 /** @var string[] List of DBO_* flags that can be changed after connection */
224 protected static $MUTABLE_FLAGS = [
225 'DBO_DEBUG',
226 'DBO_NOBUFFER',
227 'DBO_TRX',
228 'DBO_DDLMODE',
229 ];
230 /** @var int Bit field of all DBO_* flags that can be changed after connection */
231 protected static $DBO_MUTABLE = (
232 self::DBO_DEBUG | self::DBO_NOBUFFER | self::DBO_TRX | self::DBO_DDLMODE
233 );
234
235 /**
236 * @note exceptions for missing libraries/drivers should be thrown in initConnection()
237 * @param array $params Parameters passed from Database::factory()
238 */
239 public function __construct( array $params ) {
240 $this->connectionParams = [];
241 foreach ( [ 'host', 'user', 'password', 'dbname', 'schema', 'tablePrefix' ] as $name ) {
242 $this->connectionParams[$name] = $params[$name];
243 }
244 $this->connectionVariables = $params['variables'] ?? [];
245 $this->cliMode = $params['cliMode'];
246 $this->agent = $params['agent'];
247 $this->flags = $params['flags'];
248 if ( $this->flags & self::DBO_DEFAULT ) {
249 if ( $this->cliMode ) {
250 $this->flags &= ~self::DBO_TRX;
251 } else {
252 $this->flags |= self::DBO_TRX;
253 }
254 }
255 $this->nonNativeInsertSelectBatchSize = $params['nonNativeInsertSelectBatchSize'] ?? 10000;
256
257 $this->srvCache = $params['srvCache'] ?? new HashBagOStuff();
258 $this->profiler = is_callable( $params['profiler'] ) ? $params['profiler'] : null;
259 $this->trxProfiler = $params['trxProfiler'];
260 $this->connLogger = $params['connLogger'];
261 $this->queryLogger = $params['queryLogger'];
262 $this->errorLogger = $params['errorLogger'];
263 $this->deprecationLogger = $params['deprecationLogger'];
264
265 // Set initial dummy domain until open() sets the final DB/prefix
266 $this->currentDomain = new DatabaseDomain(
267 $params['dbname'] != '' ? $params['dbname'] : null,
268 $params['schema'] != '' ? $params['schema'] : null,
269 $params['tablePrefix']
270 );
271 }
272
273 /**
274 * Initialize the connection to the database over the wire (or to local files)
275 *
276 * @throws LogicException
277 * @throws InvalidArgumentException
278 * @throws DBConnectionError
279 * @since 1.31
280 */
281 final public function initConnection() {
282 if ( $this->isOpen() ) {
283 throw new LogicException( __METHOD__ . ': already connected' );
284 }
285 // Establish the connection
286 $this->doInitConnection();
287 }
288
289 /**
290 * Actually connect to the database over the wire (or to local files)
291 *
292 * @throws DBConnectionError
293 * @since 1.31
294 */
295 protected function doInitConnection() {
296 $this->open(
297 $this->connectionParams['host'],
298 $this->connectionParams['user'],
299 $this->connectionParams['password'],
300 $this->connectionParams['dbname'],
301 $this->connectionParams['schema'],
302 $this->connectionParams['tablePrefix']
303 );
304 }
305
306 /**
307 * Open a new connection to the database (closing any existing one)
308 *
309 * @param string|null $server Database server host
310 * @param string|null $user Database user name
311 * @param string|null $password Database user password
312 * @param string|null $dbName Database name
313 * @param string|null $schema Database schema name
314 * @param string $tablePrefix Table prefix
315 * @throws DBConnectionError
316 */
317 abstract protected function open( $server, $user, $password, $dbName, $schema, $tablePrefix );
318
319 /**
320 * Construct a Database subclass instance given a database type and parameters
321 *
322 * This also connects to the database immediately upon object construction
323 *
324 * @param string $type A possible DB type (sqlite, mysql, postgres,...)
325 * @param array $params Parameter map with keys:
326 * - host : The hostname of the DB server
327 * - user : The name of the database user the client operates under
328 * - password : The password for the database user
329 * - dbname : The name of the database to use where queries do not specify one.
330 * The database must exist or an error might be thrown. Setting this to the empty string
331 * will avoid any such errors and make the handle have no implicit database scope. This is
332 * useful for queries like SHOW STATUS, CREATE DATABASE, or DROP DATABASE. Note that a
333 * "database" in Postgres is rougly equivalent to an entire MySQL server. This the domain
334 * in which user names and such are defined, e.g. users are database-specific in Postgres.
335 * - schema : The database schema to use (if supported). A "schema" in Postgres is roughly
336 * equivalent to a "database" in MySQL. Note that MySQL and SQLite do not use schemas.
337 * - tablePrefix : Optional table prefix that is implicitly added on to all table names
338 * recognized in queries. This can be used in place of schemas for handle site farms.
339 * - flags : Optional bit field of DBO_* constants that define connection, protocol,
340 * buffering, and transaction behavior. It is STRONGLY adviced to leave the DBO_DEFAULT
341 * flag in place UNLESS this this database simply acts as a key/value store.
342 * - driver: Optional name of a specific DB client driver. For MySQL, there is only the
343 * 'mysqli' driver; the old one 'mysql' has been removed.
344 * - variables: Optional map of session variables to set after connecting. This can be
345 * used to adjust lock timeouts or encoding modes and the like.
346 * - connLogger: Optional PSR-3 logger interface instance.
347 * - queryLogger: Optional PSR-3 logger interface instance.
348 * - profiler : Optional callback that takes a section name argument and returns
349 * a ScopedCallback instance that ends the profile section in its destructor.
350 * These will be called in query(), using a simplified version of the SQL that
351 * also includes the agent as a SQL comment.
352 * - trxProfiler: Optional TransactionProfiler instance.
353 * - errorLogger: Optional callback that takes an Exception and logs it.
354 * - deprecationLogger: Optional callback that takes a string and logs it.
355 * - cliMode: Whether to consider the execution context that of a CLI script.
356 * - agent: Optional name used to identify the end-user in query profiling/logging.
357 * - srvCache: Optional BagOStuff instance to an APC-style cache.
358 * - nonNativeInsertSelectBatchSize: Optional batch size for non-native INSERT SELECT emulation.
359 * @param int $connect One of the class constants (NEW_CONNECTED, NEW_UNCONNECTED) [optional]
360 * @return Database|null If the database driver or extension cannot be found
361 * @throws InvalidArgumentException If the database driver or extension cannot be found
362 * @since 1.18
363 */
364 final public static function factory( $type, $params = [], $connect = self::NEW_CONNECTED ) {
365 $class = self::getClass( $type, $params['driver'] ?? null );
366
367 if ( class_exists( $class ) && is_subclass_of( $class, IDatabase::class ) ) {
368 $params += [
369 'host' => null,
370 'user' => null,
371 'password' => null,
372 'dbname' => null,
373 'schema' => null,
374 'tablePrefix' => '',
375 'flags' => 0,
376 'variables' => [],
377 'cliMode' => ( PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg' ),
378 'agent' => basename( $_SERVER['SCRIPT_NAME'] ) . '@' . gethostname()
379 ];
380
381 $normalizedParams = [
382 // Configuration
383 'host' => strlen( $params['host'] ) ? $params['host'] : null,
384 'user' => strlen( $params['user'] ) ? $params['user'] : null,
385 'password' => is_string( $params['password'] ) ? $params['password'] : null,
386 'dbname' => strlen( $params['dbname'] ) ? $params['dbname'] : null,
387 'schema' => strlen( $params['schema'] ) ? $params['schema'] : null,
388 'tablePrefix' => (string)$params['tablePrefix'],
389 'flags' => (int)$params['flags'],
390 'variables' => $params['variables'],
391 'cliMode' => (bool)$params['cliMode'],
392 'agent' => (string)$params['agent'],
393 // Objects and callbacks
394 'srvCache' => $params['srvCache'] ?? new HashBagOStuff(),
395 'profiler' => $params['profiler'] ?? null,
396 'trxProfiler' => $params['trxProfiler'] ?? new TransactionProfiler(),
397 'connLogger' => $params['connLogger'] ?? new NullLogger(),
398 'queryLogger' => $params['queryLogger'] ?? new NullLogger(),
399 'errorLogger' => $params['errorLogger'] ?? function ( Exception $e ) {
400 trigger_error( get_class( $e ) . ': ' . $e->getMessage(), E_USER_WARNING );
401 },
402 'deprecationLogger' => $params['deprecationLogger'] ?? function ( $msg ) {
403 trigger_error( $msg, E_USER_DEPRECATED );
404 }
405 ] + $params;
406
407 /** @var Database $conn */
408 $conn = new $class( $normalizedParams );
409 if ( $connect === self::NEW_CONNECTED ) {
410 $conn->initConnection();
411 }
412 } else {
413 $conn = null;
414 }
415
416 return $conn;
417 }
418
419 /**
420 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
421 * @param string|null $driver Optional name of a specific DB client driver
422 * @return array Map of (Database::ATTR_* constant => value) for all such constants
423 * @throws InvalidArgumentException
424 * @since 1.31
425 */
426 final public static function attributesFromType( $dbType, $driver = null ) {
427 static $defaults = [
428 self::ATTR_DB_LEVEL_LOCKING => false,
429 self::ATTR_SCHEMAS_AS_TABLE_GROUPS => false
430 ];
431
432 $class = self::getClass( $dbType, $driver );
433
434 return call_user_func( [ $class, 'getAttributes' ] ) + $defaults;
435 }
436
437 /**
438 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
439 * @param string|null $driver Optional name of a specific DB client driver
440 * @return string Database subclass name to use
441 * @throws InvalidArgumentException
442 */
443 private static function getClass( $dbType, $driver = null ) {
444 // For database types with built-in support, the below maps type to IDatabase
445 // implementations. For types with multipe driver implementations (PHP extensions),
446 // an array can be used, keyed by extension name. In case of an array, the
447 // optional 'driver' parameter can be used to force a specific driver. Otherwise,
448 // we auto-detect the first available driver. For types without built-in support,
449 // an class named "Database<Type>" us used, eg. DatabaseFoo for type 'foo'.
450 static $builtinTypes = [
451 'mysql' => [ 'mysqli' => DatabaseMysqli::class ],
452 'sqlite' => DatabaseSqlite::class,
453 'postgres' => DatabasePostgres::class,
454 ];
455
456 $dbType = strtolower( $dbType );
457 $class = false;
458
459 if ( isset( $builtinTypes[$dbType] ) ) {
460 $possibleDrivers = $builtinTypes[$dbType];
461 if ( is_string( $possibleDrivers ) ) {
462 $class = $possibleDrivers;
463 } elseif ( (string)$driver !== '' ) {
464 if ( !isset( $possibleDrivers[$driver] ) ) {
465 throw new InvalidArgumentException( __METHOD__ .
466 " type '$dbType' does not support driver '{$driver}'" );
467 }
468
469 $class = $possibleDrivers[$driver];
470 } else {
471 foreach ( $possibleDrivers as $posDriver => $possibleClass ) {
472 if ( extension_loaded( $posDriver ) ) {
473 $class = $possibleClass;
474 break;
475 }
476 }
477 }
478 } else {
479 $class = 'Database' . ucfirst( $dbType );
480 }
481
482 if ( $class === false ) {
483 throw new InvalidArgumentException( __METHOD__ .
484 " no viable database extension found for type '$dbType'" );
485 }
486
487 return $class;
488 }
489
490 /**
491 * @return array Map of (Database::ATTR_* constant => value)
492 * @since 1.31
493 */
494 protected static function getAttributes() {
495 return [];
496 }
497
498 /**
499 * Set the PSR-3 logger interface to use for query logging. (The logger
500 * interfaces for connection logging and error logging can be set with the
501 * constructor.)
502 *
503 * @param LoggerInterface $logger
504 */
505 public function setLogger( LoggerInterface $logger ) {
506 $this->queryLogger = $logger;
507 }
508
509 public function getServerInfo() {
510 return $this->getServerVersion();
511 }
512
513 /**
514 * Backwards-compatibility no-op method for disabling query buffering
515 *
516 * @param null|bool $buffer Whether to buffer queries (ignored)
517 * @return bool Whether buffering was already enabled (always true)
518 * @deprecated Since 1.34 Use query batching; this no longer does anything
519 */
520 public function bufferResults( $buffer = null ) {
521 return true;
522 }
523
524 final public function trxLevel() {
525 return ( $this->trxShortId != '' ) ? 1 : 0;
526 }
527
528 public function trxTimestamp() {
529 return $this->trxLevel() ? $this->trxTimestamp : null;
530 }
531
532 /**
533 * @return int One of the STATUS_TRX_* class constants
534 * @since 1.31
535 */
536 public function trxStatus() {
537 return $this->trxStatus;
538 }
539
540 public function tablePrefix( $prefix = null ) {
541 $old = $this->currentDomain->getTablePrefix();
542 if ( $prefix !== null ) {
543 $this->currentDomain = new DatabaseDomain(
544 $this->currentDomain->getDatabase(),
545 $this->currentDomain->getSchema(),
546 $prefix
547 );
548 }
549
550 return $old;
551 }
552
553 public function dbSchema( $schema = null ) {
554 if ( strlen( $schema ) && $this->getDBname() === null ) {
555 throw new DBUnexpectedError( $this, "Cannot set schema to '$schema'; no database set" );
556 }
557
558 $old = $this->currentDomain->getSchema();
559 if ( $schema !== null ) {
560 $this->currentDomain = new DatabaseDomain(
561 $this->currentDomain->getDatabase(),
562 // DatabaseDomain uses null for unspecified schemas
563 strlen( $schema ) ? $schema : null,
564 $this->currentDomain->getTablePrefix()
565 );
566 }
567
568 return (string)$old;
569 }
570
571 /**
572 * @return string Schema to use to qualify relations in queries
573 */
574 protected function relationSchemaQualifier() {
575 return $this->dbSchema();
576 }
577
578 public function getLBInfo( $name = null ) {
579 if ( is_null( $name ) ) {
580 return $this->lbInfo;
581 }
582
583 if ( array_key_exists( $name, $this->lbInfo ) ) {
584 return $this->lbInfo[$name];
585 }
586
587 return null;
588 }
589
590 public function setLBInfo( $nameOrArray, $value = null ) {
591 if ( is_array( $nameOrArray ) ) {
592 $this->lbInfo = $nameOrArray;
593 } elseif ( is_string( $nameOrArray ) ) {
594 if ( $value !== null ) {
595 $this->lbInfo[$nameOrArray] = $value;
596 } else {
597 unset( $this->lbInfo[$nameOrArray] );
598 }
599 } else {
600 throw new InvalidArgumentException( "Got non-string key" );
601 }
602 }
603
604 public function setLazyMasterHandle( IDatabase $conn ) {
605 $this->lazyMasterHandle = $conn;
606 }
607
608 /**
609 * @return IDatabase|null
610 * @see setLazyMasterHandle()
611 * @since 1.27
612 */
613 protected function getLazyMasterHandle() {
614 return $this->lazyMasterHandle;
615 }
616
617 public function implicitOrderby() {
618 return true;
619 }
620
621 public function lastQuery() {
622 return $this->lastQuery;
623 }
624
625 public function lastDoneWrites() {
626 return $this->lastWriteTime ?: false;
627 }
628
629 public function writesPending() {
630 return $this->trxLevel() && $this->trxDoneWrites;
631 }
632
633 public function writesOrCallbacksPending() {
634 return $this->trxLevel() && (
635 $this->trxDoneWrites ||
636 $this->trxIdleCallbacks ||
637 $this->trxPreCommitCallbacks ||
638 $this->trxEndCallbacks ||
639 $this->trxSectionCancelCallbacks
640 );
641 }
642
643 public function preCommitCallbacksPending() {
644 return $this->trxLevel() && $this->trxPreCommitCallbacks;
645 }
646
647 /**
648 * @return string|null
649 */
650 final protected function getTransactionRoundId() {
651 // If transaction round participation is enabled, see if one is active
652 if ( $this->getFlag( self::DBO_TRX ) ) {
653 $id = $this->getLBInfo( 'trxRoundId' );
654
655 return is_string( $id ) ? $id : null;
656 }
657
658 return null;
659 }
660
661 public function pendingWriteQueryDuration( $type = self::ESTIMATE_TOTAL ) {
662 if ( !$this->trxLevel() ) {
663 return false;
664 } elseif ( !$this->trxDoneWrites ) {
665 return 0.0;
666 }
667
668 switch ( $type ) {
669 case self::ESTIMATE_DB_APPLY:
670 return $this->pingAndCalculateLastTrxApplyTime();
671 default: // everything
672 return $this->trxWriteDuration;
673 }
674 }
675
676 /**
677 * @return float Time to apply writes to replicas based on trxWrite* fields
678 */
679 private function pingAndCalculateLastTrxApplyTime() {
680 $this->ping( $rtt );
681
682 $rttAdjTotal = $this->trxWriteAdjQueryCount * $rtt;
683 $applyTime = max( $this->trxWriteAdjDuration - $rttAdjTotal, 0 );
684 // For omitted queries, make them count as something at least
685 $omitted = $this->trxWriteQueryCount - $this->trxWriteAdjQueryCount;
686 $applyTime += self::$TINY_WRITE_SEC * $omitted;
687
688 return $applyTime;
689 }
690
691 public function pendingWriteCallers() {
692 return $this->trxLevel() ? $this->trxWriteCallers : [];
693 }
694
695 public function pendingWriteRowsAffected() {
696 return $this->trxWriteAffectedRows;
697 }
698
699 /**
700 * List the methods that have write queries or callbacks for the current transaction
701 *
702 * This method should not be used outside of Database/LoadBalancer
703 *
704 * @return string[]
705 * @since 1.32
706 */
707 public function pendingWriteAndCallbackCallers() {
708 $fnames = $this->pendingWriteCallers();
709 foreach ( [
710 $this->trxIdleCallbacks,
711 $this->trxPreCommitCallbacks,
712 $this->trxEndCallbacks,
713 $this->trxSectionCancelCallbacks
714 ] as $callbacks ) {
715 foreach ( $callbacks as $callback ) {
716 $fnames[] = $callback[1];
717 }
718 }
719
720 return $fnames;
721 }
722
723 /**
724 * @return string
725 */
726 private function flatAtomicSectionList() {
727 return array_reduce( $this->trxAtomicLevels, function ( $accum, $v ) {
728 return $accum === null ? $v[0] : "$accum, " . $v[0];
729 } );
730 }
731
732 public function isOpen() {
733 return (bool)$this->conn;
734 }
735
736 public function setFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
737 if ( $flag & ~static::$DBO_MUTABLE ) {
738 throw new DBUnexpectedError(
739 $this,
740 "Got $flag (allowed: " . implode( ', ', static::$MUTABLE_FLAGS ) . ')'
741 );
742 }
743
744 if ( $remember === self::REMEMBER_PRIOR ) {
745 array_push( $this->priorFlags, $this->flags );
746 }
747
748 $this->flags |= $flag;
749 }
750
751 public function clearFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
752 if ( $flag & ~static::$DBO_MUTABLE ) {
753 throw new DBUnexpectedError(
754 $this,
755 "Got $flag (allowed: " . implode( ', ', static::$MUTABLE_FLAGS ) . ')'
756 );
757 }
758
759 if ( $remember === self::REMEMBER_PRIOR ) {
760 array_push( $this->priorFlags, $this->flags );
761 }
762
763 $this->flags &= ~$flag;
764 }
765
766 public function restoreFlags( $state = self::RESTORE_PRIOR ) {
767 if ( !$this->priorFlags ) {
768 return;
769 }
770
771 if ( $state === self::RESTORE_INITIAL ) {
772 $this->flags = reset( $this->priorFlags );
773 $this->priorFlags = [];
774 } else {
775 $this->flags = array_pop( $this->priorFlags );
776 }
777 }
778
779 public function getFlag( $flag ) {
780 return ( ( $this->flags & $flag ) === $flag );
781 }
782
783 public function getDomainID() {
784 return $this->currentDomain->getId();
785 }
786
787 /**
788 * Get information about an index into an object
789 * @param string $table Table name
790 * @param string $index Index name
791 * @param string $fname Calling function name
792 * @return mixed Database-specific index description class or false if the index does not exist
793 */
794 abstract function indexInfo( $table, $index, $fname = __METHOD__ );
795
796 /**
797 * Wrapper for addslashes()
798 *
799 * @param string $s String to be slashed.
800 * @return string Slashed string.
801 */
802 abstract function strencode( $s );
803
804 /**
805 * Set a custom error handler for logging errors during database connection
806 */
807 protected function installErrorHandler() {
808 $this->lastPhpError = false;
809 $this->htmlErrors = ini_set( 'html_errors', '0' );
810 set_error_handler( [ $this, 'connectionErrorLogger' ] );
811 }
812
813 /**
814 * Restore the previous error handler and return the last PHP error for this DB
815 *
816 * @return bool|string
817 */
818 protected function restoreErrorHandler() {
819 restore_error_handler();
820 if ( $this->htmlErrors !== false ) {
821 ini_set( 'html_errors', $this->htmlErrors );
822 }
823
824 return $this->getLastPHPError();
825 }
826
827 /**
828 * @return string|bool Last PHP error for this DB (typically connection errors)
829 */
830 protected function getLastPHPError() {
831 if ( $this->lastPhpError ) {
832 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->lastPhpError );
833 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
834
835 return $error;
836 }
837
838 return false;
839 }
840
841 /**
842 * Error handler for logging errors during database connection
843 * This method should not be used outside of Database classes
844 *
845 * @param int $errno
846 * @param string $errstr
847 */
848 public function connectionErrorLogger( $errno, $errstr ) {
849 $this->lastPhpError = $errstr;
850 }
851
852 /**
853 * Create a log context to pass to PSR-3 logger functions.
854 *
855 * @param array $extras Additional data to add to context
856 * @return array
857 */
858 protected function getLogContext( array $extras = [] ) {
859 return array_merge(
860 [
861 'db_server' => $this->server,
862 'db_name' => $this->getDBname(),
863 'db_user' => $this->user,
864 ],
865 $extras
866 );
867 }
868
869 final public function close() {
870 $exception = null; // error to throw after disconnecting
871
872 $wasOpen = (bool)$this->conn;
873 // This should mostly do nothing if the connection is already closed
874 if ( $this->conn ) {
875 // Roll back any dangling transaction first
876 if ( $this->trxLevel() ) {
877 if ( $this->trxAtomicLevels ) {
878 // Cannot let incomplete atomic sections be committed
879 $levels = $this->flatAtomicSectionList();
880 $exception = new DBUnexpectedError(
881 $this,
882 __METHOD__ . ": atomic sections $levels are still open"
883 );
884 } elseif ( $this->trxAutomatic ) {
885 // Only the connection manager can commit non-empty DBO_TRX transactions
886 // (empty ones we can silently roll back)
887 if ( $this->writesOrCallbacksPending() ) {
888 $exception = new DBUnexpectedError(
889 $this,
890 __METHOD__ .
891 ": mass commit/rollback of peer transaction required (DBO_TRX set)"
892 );
893 }
894 } else {
895 // Manual transactions should have been committed or rolled
896 // back, even if empty.
897 $exception = new DBUnexpectedError(
898 $this,
899 __METHOD__ . ": transaction is still open (from {$this->trxFname})"
900 );
901 }
902
903 if ( $this->trxEndCallbacksSuppressed ) {
904 $exception = $exception ?: new DBUnexpectedError(
905 $this,
906 __METHOD__ . ': callbacks are suppressed; cannot properly commit'
907 );
908 }
909
910 // Rollback the changes and run any callbacks as needed
911 $this->rollback( __METHOD__, self::FLUSHING_INTERNAL );
912 }
913
914 // Close the actual connection in the binding handle
915 $closed = $this->closeConnection();
916 } else {
917 $closed = true; // already closed; nothing to do
918 }
919
920 $this->conn = null;
921
922 // Throw any unexpected errors after having disconnected
923 if ( $exception instanceof Exception ) {
924 throw $exception;
925 }
926
927 // Note that various subclasses call close() at the start of open(), which itself is
928 // called by replaceLostConnection(). In that case, just because onTransactionResolution()
929 // callbacks are pending does not mean that an exception should be thrown. Rather, they
930 // will be executed after the reconnection step.
931 if ( $wasOpen ) {
932 // Sanity check that no callbacks are dangling
933 $fnames = $this->pendingWriteAndCallbackCallers();
934 if ( $fnames ) {
935 throw new RuntimeException(
936 "Transaction callbacks are still pending: " . implode( ', ', $fnames )
937 );
938 }
939 }
940
941 return $closed;
942 }
943
944 /**
945 * Make sure there is an open connection handle (alive or not) as a sanity check
946 *
947 * This guards against fatal errors to the binding handle not being defined
948 * in cases where open() was never called or close() was already called
949 *
950 * @throws DBUnexpectedError
951 */
952 final protected function assertHasConnectionHandle() {
953 if ( !$this->isOpen() ) {
954 throw new DBUnexpectedError( $this, "DB connection was already closed" );
955 }
956 }
957
958 /**
959 * Make sure that this server is not marked as a replica nor read-only as a sanity check
960 *
961 * @throws DBReadOnlyRoleError
962 * @throws DBReadOnlyError
963 */
964 protected function assertIsWritableMaster() {
965 if ( $this->getLBInfo( 'replica' ) ) {
966 throw new DBReadOnlyRoleError(
967 $this,
968 'Write operations are not allowed on replica database connections'
969 );
970 }
971 $reason = $this->getReadOnlyReason();
972 if ( $reason !== false ) {
973 throw new DBReadOnlyError( $this, "Database is read-only: $reason" );
974 }
975 }
976
977 /**
978 * Closes underlying database connection
979 * @since 1.20
980 * @return bool Whether connection was closed successfully
981 */
982 abstract protected function closeConnection();
983
984 /**
985 * Run a query and return a DBMS-dependent wrapper or boolean
986 *
987 * This is meant to handle the basic command of actually sending a query to the
988 * server via the driver. No implicit transaction, reconnection, nor retry logic
989 * should happen here. The higher level query() method is designed to handle those
990 * sorts of concerns. This method should not trigger such higher level methods.
991 *
992 * The lastError() and lastErrno() methods should meaningfully reflect what error,
993 * if any, occured during the last call to this method. Methods like executeQuery(),
994 * query(), select(), insert(), update(), delete(), and upsert() implement their calls
995 * to doQuery() such that an immediately subsequent call to lastError()/lastErrno()
996 * meaningfully reflects any error that occured during that public query method call.
997 *
998 * For SELECT queries, this returns either:
999 * - a) A driver-specific value/resource, only on success. This can be iterated
1000 * over by calling fetchObject()/fetchRow() until there are no more rows.
1001 * Alternatively, the result can be passed to resultObject() to obtain an
1002 * IResultWrapper instance which can then be iterated over via "foreach".
1003 * - b) False, on any query failure
1004 *
1005 * For non-SELECT queries, this returns either:
1006 * - a) A driver-specific value/resource, only on success
1007 * - b) True, only on success (e.g. no meaningful result other than "OK")
1008 * - c) False, on any query failure
1009 *
1010 * @param string $sql SQL query
1011 * @return mixed|bool An object, resource, or true on success; false on failure
1012 */
1013 abstract protected function doQuery( $sql );
1014
1015 /**
1016 * Determine whether a query writes to the DB. When in doubt, this returns true.
1017 *
1018 * Main use cases:
1019 *
1020 * - Subsequent web requests should not need to wait for replication from
1021 * the master position seen by this web request, unless this request made
1022 * changes to the master. This is handled by ChronologyProtector by checking
1023 * doneWrites() at the end of the request. doneWrites() returns true if any
1024 * query set lastWriteTime; which query() does based on isWriteQuery().
1025 *
1026 * - Reject write queries to replica DBs, in query().
1027 *
1028 * @param string $sql
1029 * @return bool
1030 */
1031 protected function isWriteQuery( $sql ) {
1032 // BEGIN and COMMIT queries are considered read queries here.
1033 // Database backends and drivers (MySQL, MariaDB, php-mysqli) generally
1034 // treat these as write queries, in that their results have "affected rows"
1035 // as meta data as from writes, instead of "num rows" as from reads.
1036 // But, we treat them as read queries because when reading data (from
1037 // either replica or master) we use transactions to enable repeatable-read
1038 // snapshots, which ensures we get consistent results from the same snapshot
1039 // for all queries within a request. Use cases:
1040 // - Treating these as writes would trigger ChronologyProtector (see method doc).
1041 // - We use this method to reject writes to replicas, but we need to allow
1042 // use of transactions on replicas for read snapshots. This is fine given
1043 // that transactions by themselves don't make changes, only actual writes
1044 // within the transaction matter, which we still detect.
1045 return !preg_match(
1046 '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SAVEPOINT|RELEASE|SET|SHOW|EXPLAIN|USE|\(SELECT)\b/i',
1047 $sql
1048 );
1049 }
1050
1051 /**
1052 * @param string $sql
1053 * @return string|null
1054 */
1055 protected function getQueryVerb( $sql ) {
1056 return preg_match( '/^\s*([a-z]+)/i', $sql, $m ) ? strtoupper( $m[1] ) : null;
1057 }
1058
1059 /**
1060 * Determine whether a SQL statement is sensitive to isolation level.
1061 *
1062 * A SQL statement is considered transactable if its result could vary
1063 * depending on the transaction isolation level. Operational commands
1064 * such as 'SET' and 'SHOW' are not considered to be transactable.
1065 *
1066 * Main purpose: Used by query() to decide whether to begin a transaction
1067 * before the current query (in DBO_TRX mode, on by default).
1068 *
1069 * @param string $sql
1070 * @return bool
1071 */
1072 protected function isTransactableQuery( $sql ) {
1073 return !in_array(
1074 $this->getQueryVerb( $sql ),
1075 [ 'BEGIN', 'ROLLBACK', 'COMMIT', 'SET', 'SHOW', 'CREATE', 'ALTER', 'USE', 'SHOW' ],
1076 true
1077 );
1078 }
1079
1080 /**
1081 * @param string $sql A SQL query
1082 * @param bool $pseudoPermanent Treat any table from CREATE TEMPORARY as pseudo-permanent
1083 * @return array A n-tuple of:
1084 * - int|null: A self::TEMP_* constant for temp table operations or null otherwise
1085 * - string|null: The name of the new temporary table $sql creates, or null
1086 * - string|null: The name of the temporary table that $sql drops, or null
1087 */
1088 protected function getTempWrites( $sql, $pseudoPermanent ) {
1089 static $qt = '[`"\']?(\w+)[`"\']?'; // quoted table
1090
1091 if ( preg_match(
1092 '/^CREATE\s+TEMPORARY\s+TABLE\s+(?:IF\s+NOT\s+EXISTS\s+)?' . $qt . '/i',
1093 $sql,
1094 $matches
1095 ) ) {
1096 $type = $pseudoPermanent ? self::$TEMP_PSEUDO_PERMANENT : self::$TEMP_NORMAL;
1097
1098 return [ $type, $matches[1], null ];
1099 } elseif ( preg_match(
1100 '/^DROP\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?' . $qt . '/i',
1101 $sql,
1102 $matches
1103 ) ) {
1104 return [ $this->sessionTempTables[$matches[1]] ?? null, null, $matches[1] ];
1105 } elseif ( preg_match(
1106 '/^TRUNCATE\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?' . $qt . '/i',
1107 $sql,
1108 $matches
1109 ) ) {
1110 return [ $this->sessionTempTables[$matches[1]] ?? null, null, null ];
1111 } elseif ( preg_match(
1112 '/^(?:(?:INSERT|REPLACE)\s+(?:\w+\s+)?INTO|UPDATE|DELETE\s+FROM)\s+' . $qt . '/i',
1113 $sql,
1114 $matches
1115 ) ) {
1116 return [ $this->sessionTempTables[$matches[1]] ?? null, null, null ];
1117 }
1118
1119 return [ null, null, null ];
1120 }
1121
1122 /**
1123 * @param IResultWrapper|bool $ret
1124 * @param int|null $tmpType TEMP_NORMAL or TEMP_PSEUDO_PERMANENT
1125 * @param string|null $tmpNew Name of created temp table
1126 * @param string|null $tmpDel Name of dropped temp table
1127 */
1128 protected function registerTempWrites( $ret, $tmpType, $tmpNew, $tmpDel ) {
1129 if ( $ret !== false ) {
1130 if ( $tmpNew !== null ) {
1131 $this->sessionTempTables[$tmpNew] = $tmpType;
1132 }
1133 if ( $tmpDel !== null ) {
1134 unset( $this->sessionTempTables[$tmpDel] );
1135 }
1136 }
1137 }
1138
1139 public function query( $sql, $fname = __METHOD__, $flags = 0 ) {
1140 $flags = (int)$flags; // b/c; this field used to be a bool
1141 // Sanity check that the SQL query is appropriate in the current context and is
1142 // allowed for an outside caller (e.g. does not break transaction/session tracking).
1143 $this->assertQueryIsCurrentlyAllowed( $sql, $fname );
1144
1145 // Send the query to the server and fetch any corresponding errors
1146 list( $ret, $err, $errno, $unignorable ) = $this->executeQuery( $sql, $fname, $flags );
1147 if ( $ret === false ) {
1148 $ignoreErrors = $this->fieldHasBit( $flags, self::QUERY_SILENCE_ERRORS );
1149 // Throw an error unless both the ignore flag was set and a rollback is not needed
1150 $this->reportQueryError( $err, $errno, $sql, $fname, $ignoreErrors && !$unignorable );
1151 }
1152
1153 return $this->resultObject( $ret );
1154 }
1155
1156 /**
1157 * Execute a query, retrying it if there is a recoverable connection loss
1158 *
1159 * This is similar to query() except:
1160 * - It does not prevent all non-ROLLBACK queries if there is a corrupted transaction
1161 * - It does not disallow raw queries that are supposed to use dedicated IDatabase methods
1162 * - It does not throw exceptions for common error cases
1163 *
1164 * This is meant for internal use with Database subclasses.
1165 *
1166 * @param string $sql Original SQL query
1167 * @param string $fname Name of the calling function
1168 * @param int $flags Bit field of class QUERY_* constants
1169 * @return array An n-tuple of:
1170 * - mixed|bool: An object, resource, or true on success; false on failure
1171 * - string: The result of calling lastError()
1172 * - int: The result of calling lastErrno()
1173 * - bool: Whether a rollback is needed to allow future non-rollback queries
1174 * @throws DBUnexpectedError
1175 */
1176 final protected function executeQuery( $sql, $fname, $flags ) {
1177 $this->assertHasConnectionHandle();
1178
1179 $priorTransaction = $this->trxLevel();
1180
1181 if ( $this->isWriteQuery( $sql ) ) {
1182 // In theory, non-persistent writes are allowed in read-only mode, but due to things
1183 // like https://bugs.mysql.com/bug.php?id=33669 that might not work anyway...
1184 $this->assertIsWritableMaster();
1185 // Do not treat temporary table writes as "meaningful writes" since they are only
1186 // visible to one session and are not permanent. Profile them as reads. Integration
1187 // tests can override this behavior via $flags.
1188 $pseudoPermanent = $this->fieldHasBit( $flags, self::QUERY_PSEUDO_PERMANENT );
1189 list( $tmpType, $tmpNew, $tmpDel ) = $this->getTempWrites( $sql, $pseudoPermanent );
1190 $isPermWrite = ( $tmpType !== self::$TEMP_NORMAL );
1191 // DBConnRef uses QUERY_REPLICA_ROLE to enforce the replica role for raw SQL queries
1192 if ( $isPermWrite && $this->fieldHasBit( $flags, self::QUERY_REPLICA_ROLE ) ) {
1193 throw new DBReadOnlyRoleError( $this, "Cannot write; target role is DB_REPLICA" );
1194 }
1195 } else {
1196 // No permanent writes in this query
1197 $isPermWrite = false;
1198 // No temporary tables written to either
1199 list( $tmpType, $tmpNew, $tmpDel ) = [ null, null, null ];
1200 }
1201
1202 // Add trace comment to the begin of the sql string, right after the operator.
1203 // Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (T44598).
1204 $encAgent = str_replace( '/', '-', $this->agent );
1205 $commentedSql = preg_replace( '/\s|$/', " /* $fname $encAgent */ ", $sql, 1 );
1206
1207 // Send the query to the server and fetch any corresponding errors.
1208 // This also doubles as a "ping" to see if the connection was dropped.
1209 list( $ret, $err, $errno, $recoverableSR, $recoverableCL, $reconnected ) =
1210 $this->executeQueryAttempt( $sql, $commentedSql, $isPermWrite, $fname, $flags );
1211
1212 // Check if the query failed due to a recoverable connection loss
1213 $allowRetry = !$this->fieldHasBit( $flags, self::QUERY_NO_RETRY );
1214 if ( $ret === false && $recoverableCL && $reconnected && $allowRetry ) {
1215 // Silently resend the query to the server since it is safe and possible
1216 list( $ret, $err, $errno, $recoverableSR, $recoverableCL ) =
1217 $this->executeQueryAttempt( $sql, $commentedSql, $isPermWrite, $fname, $flags );
1218 }
1219
1220 // Register creation and dropping of temporary tables
1221 $this->registerTempWrites( $ret, $tmpType, $tmpNew, $tmpDel );
1222
1223 $corruptedTrx = false;
1224
1225 if ( $ret === false ) {
1226 if ( $priorTransaction ) {
1227 if ( $recoverableSR ) {
1228 # We're ignoring an error that caused just the current query to be aborted.
1229 # But log the cause so we can log a deprecation notice if a caller actually
1230 # does ignore it.
1231 $this->trxStatusIgnoredCause = [ $err, $errno, $fname ];
1232 } elseif ( !$recoverableCL ) {
1233 # Either the query was aborted or all queries after BEGIN where aborted.
1234 # In the first case, the only options going forward are (a) ROLLBACK, or
1235 # (b) ROLLBACK TO SAVEPOINT (if one was set). If the later case, the only
1236 # option is ROLLBACK, since the snapshots would have been released.
1237 $corruptedTrx = true; // cannot recover
1238 $this->trxStatus = self::STATUS_TRX_ERROR;
1239 $this->trxStatusCause =
1240 $this->getQueryExceptionAndLog( $err, $errno, $sql, $fname );
1241 $this->trxStatusIgnoredCause = null;
1242 }
1243 }
1244 }
1245
1246 return [ $ret, $err, $errno, $corruptedTrx ];
1247 }
1248
1249 /**
1250 * Wrapper for doQuery() that handles DBO_TRX, profiling, logging, affected row count
1251 * tracking, and reconnects (without retry) on query failure due to connection loss
1252 *
1253 * @param string $sql Original SQL query
1254 * @param string $commentedSql SQL query with debugging/trace comment
1255 * @param bool $isPermWrite Whether the query is a (non-temporary table) write
1256 * @param string $fname Name of the calling function
1257 * @param int $flags Bit field of class QUERY_* constants
1258 * @return array An n-tuple of:
1259 * - mixed|bool: An object, resource, or true on success; false on failure
1260 * - string: The result of calling lastError()
1261 * - int: The result of calling lastErrno()
1262 * - bool: Whether a statement rollback error occured
1263 * - bool: Whether a disconnect *both* happened *and* was recoverable
1264 * - bool: Whether a reconnection attempt was *both* made *and* succeeded
1265 * @throws DBUnexpectedError
1266 */
1267 private function executeQueryAttempt( $sql, $commentedSql, $isPermWrite, $fname, $flags ) {
1268 $priorWritesPending = $this->writesOrCallbacksPending();
1269
1270 if ( ( $flags & self::QUERY_IGNORE_DBO_TRX ) == 0 ) {
1271 $this->beginIfImplied( $sql, $fname );
1272 }
1273
1274 // Keep track of whether the transaction has write queries pending
1275 if ( $isPermWrite ) {
1276 $this->lastWriteTime = microtime( true );
1277 if ( $this->trxLevel() && !$this->trxDoneWrites ) {
1278 $this->trxDoneWrites = true;
1279 $this->trxProfiler->transactionWritingIn(
1280 $this->server, $this->getDomainID(), $this->trxShortId );
1281 }
1282 }
1283
1284 $prefix = $this->getLBInfo( 'master' ) ? 'query-m: ' : 'query: ';
1285 $generalizedSql = new GeneralizedSql( $sql, $this->trxShortId, $prefix );
1286
1287 $startTime = microtime( true );
1288 $ps = $this->profiler
1289 ? ( $this->profiler )( $generalizedSql->stringify() )
1290 : null;
1291 $this->affectedRowCount = null;
1292 $this->lastQuery = $sql;
1293 $ret = $this->doQuery( $commentedSql );
1294 $lastError = $this->lastError();
1295 $lastErrno = $this->lastErrno();
1296
1297 $this->affectedRowCount = $this->affectedRows();
1298 unset( $ps ); // profile out (if set)
1299 $queryRuntime = max( microtime( true ) - $startTime, 0.0 );
1300
1301 $recoverableSR = false; // recoverable statement rollback?
1302 $recoverableCL = false; // recoverable connection loss?
1303 $reconnected = false; // reconnection both attempted and succeeded?
1304
1305 if ( $ret !== false ) {
1306 $this->lastPing = $startTime;
1307 if ( $isPermWrite && $this->trxLevel() ) {
1308 $this->updateTrxWriteQueryTime( $sql, $queryRuntime, $this->affectedRows() );
1309 $this->trxWriteCallers[] = $fname;
1310 }
1311 } elseif ( $this->wasConnectionError( $lastErrno ) ) {
1312 # Check if no meaningful session state was lost
1313 $recoverableCL = $this->canRecoverFromDisconnect( $sql, $priorWritesPending );
1314 # Update session state tracking and try to restore the connection
1315 $reconnected = $this->replaceLostConnection( __METHOD__ );
1316 } else {
1317 # Check if only the last query was rolled back
1318 $recoverableSR = $this->wasKnownStatementRollbackError();
1319 }
1320
1321 if ( $sql === self::$PING_QUERY ) {
1322 $this->lastRoundTripEstimate = $queryRuntime;
1323 }
1324
1325 $this->trxProfiler->recordQueryCompletion(
1326 $generalizedSql,
1327 $startTime,
1328 $isPermWrite,
1329 $isPermWrite ? $this->affectedRows() : $this->numRows( $ret )
1330 );
1331
1332 // Avoid the overhead of logging calls unless debug mode is enabled
1333 if ( $this->getFlag( self::DBO_DEBUG ) ) {
1334 $this->queryLogger->debug(
1335 "{method} [{runtime}s] {db_host}: $sql",
1336 [
1337 'method' => $fname,
1338 'db_host' => $this->getServer(),
1339 'domain' => $this->getDomainID(),
1340 'runtime' => round( $queryRuntime, 3 )
1341 ]
1342 );
1343 }
1344
1345 return [ $ret, $lastError, $lastErrno, $recoverableSR, $recoverableCL, $reconnected ];
1346 }
1347
1348 /**
1349 * Start an implicit transaction if DBO_TRX is enabled and no transaction is active
1350 *
1351 * @param string $sql
1352 * @param string $fname
1353 */
1354 private function beginIfImplied( $sql, $fname ) {
1355 if (
1356 !$this->trxLevel() &&
1357 $this->getFlag( self::DBO_TRX ) &&
1358 $this->isTransactableQuery( $sql )
1359 ) {
1360 $this->begin( __METHOD__ . " ($fname)", self::TRANSACTION_INTERNAL );
1361 $this->trxAutomatic = true;
1362 }
1363 }
1364
1365 /**
1366 * Update the estimated run-time of a query, not counting large row lock times
1367 *
1368 * LoadBalancer can be set to rollback transactions that will create huge replication
1369 * lag. It bases this estimate off of pendingWriteQueryDuration(). Certain simple
1370 * queries, like inserting a row can take a long time due to row locking. This method
1371 * uses some simple heuristics to discount those cases.
1372 *
1373 * @param string $sql A SQL write query
1374 * @param float $runtime Total runtime, including RTT
1375 * @param int $affected Affected row count
1376 */
1377 private function updateTrxWriteQueryTime( $sql, $runtime, $affected ) {
1378 // Whether this is indicative of replica DB runtime (except for RBR or ws_repl)
1379 $indicativeOfReplicaRuntime = true;
1380 if ( $runtime > self::$SLOW_WRITE_SEC ) {
1381 $verb = $this->getQueryVerb( $sql );
1382 // insert(), upsert(), replace() are fast unless bulky in size or blocked on locks
1383 if ( $verb === 'INSERT' ) {
1384 $indicativeOfReplicaRuntime = $this->affectedRows() > self::$SMALL_WRITE_ROWS;
1385 } elseif ( $verb === 'REPLACE' ) {
1386 $indicativeOfReplicaRuntime = $this->affectedRows() > self::$SMALL_WRITE_ROWS / 2;
1387 }
1388 }
1389
1390 $this->trxWriteDuration += $runtime;
1391 $this->trxWriteQueryCount += 1;
1392 $this->trxWriteAffectedRows += $affected;
1393 if ( $indicativeOfReplicaRuntime ) {
1394 $this->trxWriteAdjDuration += $runtime;
1395 $this->trxWriteAdjQueryCount += 1;
1396 }
1397 }
1398
1399 /**
1400 * Error out if the DB is not in a valid state for a query via query()
1401 *
1402 * @param string $sql
1403 * @param string $fname
1404 * @throws DBTransactionStateError
1405 */
1406 private function assertQueryIsCurrentlyAllowed( $sql, $fname ) {
1407 $verb = $this->getQueryVerb( $sql );
1408 if ( $verb === 'USE' ) {
1409 throw new DBUnexpectedError( $this, "Got USE query; use selectDomain() instead" );
1410 }
1411
1412 if ( $verb === 'ROLLBACK' ) { // transaction/savepoint
1413 return;
1414 }
1415
1416 if ( $this->trxStatus < self::STATUS_TRX_OK ) {
1417 throw new DBTransactionStateError(
1418 $this,
1419 "Cannot execute query from $fname while transaction status is ERROR",
1420 [],
1421 $this->trxStatusCause
1422 );
1423 } elseif ( $this->trxStatus === self::STATUS_TRX_OK && $this->trxStatusIgnoredCause ) {
1424 list( $iLastError, $iLastErrno, $iFname ) = $this->trxStatusIgnoredCause;
1425 call_user_func( $this->deprecationLogger,
1426 "Caller from $fname ignored an error originally raised from $iFname: " .
1427 "[$iLastErrno] $iLastError"
1428 );
1429 $this->trxStatusIgnoredCause = null;
1430 }
1431 }
1432
1433 public function assertNoOpenTransactions() {
1434 if ( $this->explicitTrxActive() ) {
1435 throw new DBTransactionError(
1436 $this,
1437 "Explicit transaction still active. A caller may have caught an error. "
1438 . "Open transactions: " . $this->flatAtomicSectionList()
1439 );
1440 }
1441 }
1442
1443 /**
1444 * Determine whether it is safe to retry queries after a database connection is lost
1445 *
1446 * @param string $sql SQL query
1447 * @param bool $priorWritesPending Whether there is a transaction open with
1448 * possible write queries or transaction pre-commit/idle callbacks
1449 * waiting on it to finish.
1450 * @return bool True if it is safe to retry the query, false otherwise
1451 */
1452 private function canRecoverFromDisconnect( $sql, $priorWritesPending ) {
1453 # Transaction dropped; this can mean lost writes, or REPEATABLE-READ snapshots.
1454 # Dropped connections also mean that named locks are automatically released.
1455 # Only allow error suppression in autocommit mode or when the lost transaction
1456 # didn't matter anyway (aside from DBO_TRX snapshot loss).
1457 if ( $this->sessionNamedLocks ) {
1458 return false; // possible critical section violation
1459 } elseif ( $this->sessionTempTables ) {
1460 return false; // tables might be queried latter
1461 } elseif ( $sql === 'COMMIT' ) {
1462 return !$priorWritesPending; // nothing written anyway? (T127428)
1463 } elseif ( $sql === 'ROLLBACK' ) {
1464 return true; // transaction lost...which is also what was requested :)
1465 } elseif ( $this->explicitTrxActive() ) {
1466 return false; // don't drop atomocity and explicit snapshots
1467 } elseif ( $priorWritesPending ) {
1468 return false; // prior writes lost from implicit transaction
1469 }
1470
1471 return true;
1472 }
1473
1474 /**
1475 * Clean things up after session (and thus transaction) loss before reconnect
1476 */
1477 private function handleSessionLossPreconnect() {
1478 // Clean up tracking of session-level things...
1479 // https://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html
1480 // https://www.postgresql.org/docs/9.2/static/sql-createtable.html (ignoring ON COMMIT)
1481 $this->sessionTempTables = [];
1482 // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1483 // https://www.postgresql.org/docs/9.4/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1484 $this->sessionNamedLocks = [];
1485 // Session loss implies transaction loss
1486 $oldTrxShortId = $this->consumeTrxShortId();
1487 $this->trxAtomicCounter = 0;
1488 $this->trxIdleCallbacks = []; // T67263; transaction already lost
1489 $this->trxPreCommitCallbacks = []; // T67263; transaction already lost
1490 // Clear additional subclass fields
1491 $this->doHandleSessionLossPreconnect();
1492 // @note: leave trxRecurringCallbacks in place
1493 if ( $this->trxDoneWrites ) {
1494 $this->trxProfiler->transactionWritingOut(
1495 $this->server,
1496 $this->getDomainID(),
1497 $oldTrxShortId,
1498 $this->pendingWriteQueryDuration( self::ESTIMATE_TOTAL ),
1499 $this->trxWriteAffectedRows
1500 );
1501 }
1502 }
1503
1504 /**
1505 * Reset any additional subclass trx* and session* fields
1506 */
1507 protected function doHandleSessionLossPreconnect() {
1508 // no-op
1509 }
1510
1511 /**
1512 * Clean things up after session (and thus transaction) loss after reconnect
1513 */
1514 private function handleSessionLossPostconnect() {
1515 try {
1516 // Handle callbacks in trxEndCallbacks, e.g. onTransactionResolution().
1517 // If callback suppression is set then the array will remain unhandled.
1518 $this->runOnTransactionIdleCallbacks( self::TRIGGER_ROLLBACK );
1519 } catch ( Exception $ex ) {
1520 // Already logged; move on...
1521 }
1522 try {
1523 // Handle callbacks in trxRecurringCallbacks, e.g. setTransactionListener()
1524 $this->runTransactionListenerCallbacks( self::TRIGGER_ROLLBACK );
1525 } catch ( Exception $ex ) {
1526 // Already logged; move on...
1527 }
1528 }
1529
1530 /**
1531 * Reset the transaction ID and return the old one
1532 *
1533 * @return string The old transaction ID or the empty string if there wasn't one
1534 */
1535 private function consumeTrxShortId() {
1536 $old = $this->trxShortId;
1537 $this->trxShortId = '';
1538
1539 return $old;
1540 }
1541
1542 /**
1543 * Checks whether the cause of the error is detected to be a timeout.
1544 *
1545 * It returns false by default, and not all engines support detecting this yet.
1546 * If this returns false, it will be treated as a generic query error.
1547 *
1548 * @param string $error Error text
1549 * @param int $errno Error number
1550 * @return bool
1551 */
1552 protected function wasQueryTimeout( $error, $errno ) {
1553 return false;
1554 }
1555
1556 /**
1557 * Report a query error. Log the error, and if neither the object ignore
1558 * flag nor the $ignoreErrors flag is set, throw a DBQueryError.
1559 *
1560 * @param string $error
1561 * @param int $errno
1562 * @param string $sql
1563 * @param string $fname
1564 * @param bool $ignore
1565 * @throws DBQueryError
1566 */
1567 public function reportQueryError( $error, $errno, $sql, $fname, $ignore = false ) {
1568 if ( $ignore ) {
1569 $this->queryLogger->debug( "SQL ERROR (ignored): $error" );
1570 } else {
1571 throw $this->getQueryExceptionAndLog( $error, $errno, $sql, $fname );
1572 }
1573 }
1574
1575 /**
1576 * @param string $error
1577 * @param string|int $errno
1578 * @param string $sql
1579 * @param string $fname
1580 * @return DBError
1581 */
1582 private function getQueryExceptionAndLog( $error, $errno, $sql, $fname ) {
1583 $this->queryLogger->error(
1584 "{fname}\t{db_server}\t{errno}\t{error}\t{sql1line}",
1585 $this->getLogContext( [
1586 'method' => __METHOD__,
1587 'errno' => $errno,
1588 'error' => $error,
1589 'sql1line' => mb_substr( str_replace( "\n", "\\n", $sql ), 0, 5 * 1024 ),
1590 'fname' => $fname,
1591 'trace' => ( new RuntimeException() )->getTraceAsString()
1592 ] )
1593 );
1594
1595 if ( $this->wasQueryTimeout( $error, $errno ) ) {
1596 $e = new DBQueryTimeoutError( $this, $error, $errno, $sql, $fname );
1597 } elseif ( $this->wasConnectionError( $errno ) ) {
1598 $e = new DBQueryDisconnectedError( $this, $error, $errno, $sql, $fname );
1599 } else {
1600 $e = new DBQueryError( $this, $error, $errno, $sql, $fname );
1601 }
1602
1603 return $e;
1604 }
1605
1606 /**
1607 * @param string $error
1608 * @return DBConnectionError
1609 */
1610 final protected function newExceptionAfterConnectError( $error ) {
1611 // Connection was not fully initialized and is not safe for use
1612 $this->conn = null;
1613
1614 $this->connLogger->error(
1615 "Error connecting to {db_server} as user {db_user}: {error}",
1616 $this->getLogContext( [
1617 'error' => $error,
1618 'trace' => ( new RuntimeException() )->getTraceAsString()
1619 ] )
1620 );
1621
1622 return new DBConnectionError( $this, $error );
1623 }
1624
1625 public function freeResult( $res ) {
1626 }
1627
1628 public function selectField(
1629 $table, $var, $cond = '', $fname = __METHOD__, $options = [], $join_conds = []
1630 ) {
1631 if ( $var === '*' ) { // sanity
1632 throw new DBUnexpectedError( $this, "Cannot use a * field: got '$var'" );
1633 }
1634
1635 if ( !is_array( $options ) ) {
1636 $options = [ $options ];
1637 }
1638
1639 $options['LIMIT'] = 1;
1640
1641 $res = $this->select( $table, $var, $cond, $fname, $options, $join_conds );
1642 if ( $res === false ) {
1643 throw new DBUnexpectedError( $this, "Got false from select()" );
1644 }
1645
1646 $row = $this->fetchRow( $res );
1647 if ( $row === false ) {
1648 return false;
1649 }
1650
1651 return reset( $row );
1652 }
1653
1654 public function selectFieldValues(
1655 $table, $var, $cond = '', $fname = __METHOD__, $options = [], $join_conds = []
1656 ) {
1657 if ( $var === '*' ) { // sanity
1658 throw new DBUnexpectedError( $this, "Cannot use a * field" );
1659 } elseif ( !is_string( $var ) ) { // sanity
1660 throw new DBUnexpectedError( $this, "Cannot use an array of fields" );
1661 }
1662
1663 if ( !is_array( $options ) ) {
1664 $options = [ $options ];
1665 }
1666
1667 $res = $this->select( $table, [ 'value' => $var ], $cond, $fname, $options, $join_conds );
1668 if ( $res === false ) {
1669 throw new DBUnexpectedError( $this, "Got false from select()" );
1670 }
1671
1672 $values = [];
1673 foreach ( $res as $row ) {
1674 $values[] = $row->value;
1675 }
1676
1677 return $values;
1678 }
1679
1680 /**
1681 * Returns an optional USE INDEX clause to go after the table, and a
1682 * string to go at the end of the query.
1683 *
1684 * @param array $options Associative array of options to be turned into
1685 * an SQL query, valid keys are listed in the function.
1686 * @return array
1687 * @see Database::select()
1688 */
1689 protected function makeSelectOptions( $options ) {
1690 $preLimitTail = $postLimitTail = '';
1691 $startOpts = '';
1692
1693 $noKeyOptions = [];
1694
1695 foreach ( $options as $key => $option ) {
1696 if ( is_numeric( $key ) ) {
1697 $noKeyOptions[$option] = true;
1698 }
1699 }
1700
1701 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1702
1703 $preLimitTail .= $this->makeOrderBy( $options );
1704
1705 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1706 $postLimitTail .= ' FOR UPDATE';
1707 }
1708
1709 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1710 $postLimitTail .= ' LOCK IN SHARE MODE';
1711 }
1712
1713 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1714 $startOpts .= 'DISTINCT';
1715 }
1716
1717 # Various MySQL extensions
1718 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1719 $startOpts .= ' /*! STRAIGHT_JOIN */';
1720 }
1721
1722 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1723 $startOpts .= ' SQL_BIG_RESULT';
1724 }
1725
1726 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1727 $startOpts .= ' SQL_BUFFER_RESULT';
1728 }
1729
1730 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1731 $startOpts .= ' SQL_SMALL_RESULT';
1732 }
1733
1734 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1735 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1736 }
1737
1738 if ( isset( $options['USE INDEX'] ) && is_string( $options['USE INDEX'] ) ) {
1739 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1740 } else {
1741 $useIndex = '';
1742 }
1743 if ( isset( $options['IGNORE INDEX'] ) && is_string( $options['IGNORE INDEX'] ) ) {
1744 $ignoreIndex = $this->ignoreIndexClause( $options['IGNORE INDEX'] );
1745 } else {
1746 $ignoreIndex = '';
1747 }
1748
1749 return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ];
1750 }
1751
1752 /**
1753 * Returns an optional GROUP BY with an optional HAVING
1754 *
1755 * @param array $options Associative array of options
1756 * @return string
1757 * @see Database::select()
1758 * @since 1.21
1759 */
1760 protected function makeGroupByWithHaving( $options ) {
1761 $sql = '';
1762 if ( isset( $options['GROUP BY'] ) ) {
1763 $gb = is_array( $options['GROUP BY'] )
1764 ? implode( ',', $options['GROUP BY'] )
1765 : $options['GROUP BY'];
1766 $sql .= ' GROUP BY ' . $gb;
1767 }
1768 if ( isset( $options['HAVING'] ) ) {
1769 $having = is_array( $options['HAVING'] )
1770 ? $this->makeList( $options['HAVING'], self::LIST_AND )
1771 : $options['HAVING'];
1772 $sql .= ' HAVING ' . $having;
1773 }
1774
1775 return $sql;
1776 }
1777
1778 /**
1779 * Returns an optional ORDER BY
1780 *
1781 * @param array $options Associative array of options
1782 * @return string
1783 * @see Database::select()
1784 * @since 1.21
1785 */
1786 protected function makeOrderBy( $options ) {
1787 if ( isset( $options['ORDER BY'] ) ) {
1788 $ob = is_array( $options['ORDER BY'] )
1789 ? implode( ',', $options['ORDER BY'] )
1790 : $options['ORDER BY'];
1791
1792 return ' ORDER BY ' . $ob;
1793 }
1794
1795 return '';
1796 }
1797
1798 public function select(
1799 $table, $vars, $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
1800 ) {
1801 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1802
1803 return $this->query( $sql, $fname );
1804 }
1805
1806 public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__,
1807 $options = [], $join_conds = []
1808 ) {
1809 if ( is_array( $vars ) ) {
1810 $fields = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1811 } else {
1812 $fields = $vars;
1813 }
1814
1815 $options = (array)$options;
1816 $useIndexes = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1817 ? $options['USE INDEX']
1818 : [];
1819 $ignoreIndexes = (
1820 isset( $options['IGNORE INDEX'] ) &&
1821 is_array( $options['IGNORE INDEX'] )
1822 )
1823 ? $options['IGNORE INDEX']
1824 : [];
1825
1826 if (
1827 $this->selectOptionsIncludeLocking( $options ) &&
1828 $this->selectFieldsOrOptionsAggregate( $vars, $options )
1829 ) {
1830 // Some DB types (e.g. postgres) disallow FOR UPDATE with aggregate
1831 // functions. Discourage use of such queries to encourage compatibility.
1832 call_user_func(
1833 $this->deprecationLogger,
1834 __METHOD__ . ": aggregation used with a locking SELECT ($fname)"
1835 );
1836 }
1837
1838 if ( is_array( $table ) ) {
1839 $from = ' FROM ' .
1840 $this->tableNamesWithIndexClauseOrJOIN(
1841 $table, $useIndexes, $ignoreIndexes, $join_conds );
1842 } elseif ( $table != '' ) {
1843 $from = ' FROM ' .
1844 $this->tableNamesWithIndexClauseOrJOIN(
1845 [ $table ], $useIndexes, $ignoreIndexes, [] );
1846 } else {
1847 $from = '';
1848 }
1849
1850 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ) =
1851 $this->makeSelectOptions( $options );
1852
1853 if ( is_array( $conds ) ) {
1854 $conds = $this->makeList( $conds, self::LIST_AND );
1855 }
1856
1857 if ( $conds === null || $conds === false ) {
1858 $this->queryLogger->warning(
1859 __METHOD__
1860 . ' called from '
1861 . $fname
1862 . ' with incorrect parameters: $conds must be a string or an array'
1863 );
1864 $conds = '';
1865 }
1866
1867 if ( $conds === '' || $conds === '*' ) {
1868 $sql = "SELECT $startOpts $fields $from $useIndex $ignoreIndex $preLimitTail";
1869 } elseif ( is_string( $conds ) ) {
1870 $sql = "SELECT $startOpts $fields $from $useIndex $ignoreIndex " .
1871 "WHERE $conds $preLimitTail";
1872 } else {
1873 throw new DBUnexpectedError( $this, __METHOD__ . ' called with incorrect parameters' );
1874 }
1875
1876 if ( isset( $options['LIMIT'] ) ) {
1877 $sql = $this->limitResult( $sql, $options['LIMIT'],
1878 $options['OFFSET'] ?? false );
1879 }
1880 $sql = "$sql $postLimitTail";
1881
1882 if ( isset( $options['EXPLAIN'] ) ) {
1883 $sql = 'EXPLAIN ' . $sql;
1884 }
1885
1886 return $sql;
1887 }
1888
1889 public function selectRow( $table, $vars, $conds, $fname = __METHOD__,
1890 $options = [], $join_conds = []
1891 ) {
1892 $options = (array)$options;
1893 $options['LIMIT'] = 1;
1894
1895 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1896 if ( $res === false ) {
1897 throw new DBUnexpectedError( $this, "Got false from select()" );
1898 }
1899
1900 if ( !$this->numRows( $res ) ) {
1901 return false;
1902 }
1903
1904 return $this->fetchObject( $res );
1905 }
1906
1907 public function estimateRowCount(
1908 $table, $var = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
1909 ) {
1910 $conds = $this->normalizeConditions( $conds, $fname );
1911 $column = $this->extractSingleFieldFromList( $var );
1912 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1913 $conds[] = "$column IS NOT NULL";
1914 }
1915
1916 $res = $this->select(
1917 $table, [ 'rowcount' => 'COUNT(*)' ], $conds, $fname, $options, $join_conds
1918 );
1919 $row = $res ? $this->fetchRow( $res ) : [];
1920
1921 return isset( $row['rowcount'] ) ? (int)$row['rowcount'] : 0;
1922 }
1923
1924 public function selectRowCount(
1925 $tables, $var = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
1926 ) {
1927 $conds = $this->normalizeConditions( $conds, $fname );
1928 $column = $this->extractSingleFieldFromList( $var );
1929 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1930 $conds[] = "$column IS NOT NULL";
1931 }
1932
1933 $res = $this->select(
1934 [
1935 'tmp_count' => $this->buildSelectSubquery(
1936 $tables,
1937 '1',
1938 $conds,
1939 $fname,
1940 $options,
1941 $join_conds
1942 )
1943 ],
1944 [ 'rowcount' => 'COUNT(*)' ],
1945 [],
1946 $fname
1947 );
1948 $row = $res ? $this->fetchRow( $res ) : [];
1949
1950 return isset( $row['rowcount'] ) ? (int)$row['rowcount'] : 0;
1951 }
1952
1953 /**
1954 * @param string|array $options
1955 * @return bool
1956 */
1957 private function selectOptionsIncludeLocking( $options ) {
1958 $options = (array)$options;
1959 foreach ( [ 'FOR UPDATE', 'LOCK IN SHARE MODE' ] as $lock ) {
1960 if ( in_array( $lock, $options, true ) ) {
1961 return true;
1962 }
1963 }
1964
1965 return false;
1966 }
1967
1968 /**
1969 * @param array|string $fields
1970 * @param array|string $options
1971 * @return bool
1972 */
1973 private function selectFieldsOrOptionsAggregate( $fields, $options ) {
1974 foreach ( (array)$options as $key => $value ) {
1975 if ( is_string( $key ) ) {
1976 if ( preg_match( '/^(?:GROUP BY|HAVING)$/i', $key ) ) {
1977 return true;
1978 }
1979 } elseif ( is_string( $value ) ) {
1980 if ( preg_match( '/^(?:DISTINCT|DISTINCTROW)$/i', $value ) ) {
1981 return true;
1982 }
1983 }
1984 }
1985
1986 $regex = '/^(?:COUNT|MIN|MAX|SUM|GROUP_CONCAT|LISTAGG|ARRAY_AGG)\s*\\(/i';
1987 foreach ( (array)$fields as $field ) {
1988 if ( is_string( $field ) && preg_match( $regex, $field ) ) {
1989 return true;
1990 }
1991 }
1992
1993 return false;
1994 }
1995
1996 /**
1997 * @param array|string $conds
1998 * @param string $fname
1999 * @return array
2000 */
2001 final protected function normalizeConditions( $conds, $fname ) {
2002 if ( $conds === null || $conds === false ) {
2003 $this->queryLogger->warning(
2004 __METHOD__
2005 . ' called from '
2006 . $fname
2007 . ' with incorrect parameters: $conds must be a string or an array'
2008 );
2009 $conds = '';
2010 }
2011
2012 if ( !is_array( $conds ) ) {
2013 $conds = ( $conds === '' ) ? [] : [ $conds ];
2014 }
2015
2016 return $conds;
2017 }
2018
2019 /**
2020 * @param array|string $var Field parameter in the style of select()
2021 * @return string|null Column name or null; ignores aliases
2022 * @throws DBUnexpectedError Errors out if multiple columns are given
2023 */
2024 final protected function extractSingleFieldFromList( $var ) {
2025 if ( is_array( $var ) ) {
2026 if ( !$var ) {
2027 $column = null;
2028 } elseif ( count( $var ) == 1 ) {
2029 $column = $var[0] ?? reset( $var );
2030 } else {
2031 throw new DBUnexpectedError( $this, __METHOD__ . ': got multiple columns' );
2032 }
2033 } else {
2034 $column = $var;
2035 }
2036
2037 return $column;
2038 }
2039
2040 public function lockForUpdate(
2041 $table, $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
2042 ) {
2043 if ( !$this->trxLevel() && !$this->getFlag( self::DBO_TRX ) ) {
2044 throw new DBUnexpectedError(
2045 $this,
2046 __METHOD__ . ': no transaction is active nor is DBO_TRX set'
2047 );
2048 }
2049
2050 $options = (array)$options;
2051 $options[] = 'FOR UPDATE';
2052
2053 return $this->selectRowCount( $table, '*', $conds, $fname, $options, $join_conds );
2054 }
2055
2056 public function fieldExists( $table, $field, $fname = __METHOD__ ) {
2057 $info = $this->fieldInfo( $table, $field );
2058
2059 return (bool)$info;
2060 }
2061
2062 public function indexExists( $table, $index, $fname = __METHOD__ ) {
2063 if ( !$this->tableExists( $table ) ) {
2064 return null;
2065 }
2066
2067 $info = $this->indexInfo( $table, $index, $fname );
2068 if ( is_null( $info ) ) {
2069 return null;
2070 } else {
2071 return $info !== false;
2072 }
2073 }
2074
2075 abstract public function tableExists( $table, $fname = __METHOD__ );
2076
2077 public function indexUnique( $table, $index ) {
2078 $indexInfo = $this->indexInfo( $table, $index );
2079
2080 if ( !$indexInfo ) {
2081 return null;
2082 }
2083
2084 return !$indexInfo[0]->Non_unique;
2085 }
2086
2087 /**
2088 * Helper for Database::insert().
2089 *
2090 * @param array $options
2091 * @return string
2092 */
2093 protected function makeInsertOptions( $options ) {
2094 return implode( ' ', $options );
2095 }
2096
2097 public function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
2098 # No rows to insert, easy just return now
2099 if ( !count( $a ) ) {
2100 return true;
2101 }
2102
2103 $table = $this->tableName( $table );
2104
2105 if ( !is_array( $options ) ) {
2106 $options = [ $options ];
2107 }
2108
2109 $options = $this->makeInsertOptions( $options );
2110
2111 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
2112 $multi = true;
2113 $keys = array_keys( $a[0] );
2114 } else {
2115 $multi = false;
2116 $keys = array_keys( $a );
2117 }
2118
2119 $sql = 'INSERT ' . $options .
2120 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
2121
2122 if ( $multi ) {
2123 $first = true;
2124 foreach ( $a as $row ) {
2125 if ( $first ) {
2126 $first = false;
2127 } else {
2128 $sql .= ',';
2129 }
2130 $sql .= '(' . $this->makeList( $row ) . ')';
2131 }
2132 } else {
2133 $sql .= '(' . $this->makeList( $a ) . ')';
2134 }
2135
2136 $this->query( $sql, $fname );
2137
2138 return true;
2139 }
2140
2141 /**
2142 * Make UPDATE options array for Database::makeUpdateOptions
2143 *
2144 * @param array $options
2145 * @return array
2146 */
2147 protected function makeUpdateOptionsArray( $options ) {
2148 if ( !is_array( $options ) ) {
2149 $options = [ $options ];
2150 }
2151
2152 $opts = [];
2153
2154 if ( in_array( 'IGNORE', $options ) ) {
2155 $opts[] = 'IGNORE';
2156 }
2157
2158 return $opts;
2159 }
2160
2161 /**
2162 * Make UPDATE options for the Database::update function
2163 *
2164 * @param array $options The options passed to Database::update
2165 * @return string
2166 */
2167 protected function makeUpdateOptions( $options ) {
2168 $opts = $this->makeUpdateOptionsArray( $options );
2169
2170 return implode( ' ', $opts );
2171 }
2172
2173 public function update( $table, $values, $conds, $fname = __METHOD__, $options = [] ) {
2174 $table = $this->tableName( $table );
2175 $opts = $this->makeUpdateOptions( $options );
2176 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, self::LIST_SET );
2177
2178 if ( $conds !== [] && $conds !== '*' ) {
2179 $sql .= " WHERE " . $this->makeList( $conds, self::LIST_AND );
2180 }
2181
2182 $this->query( $sql, $fname );
2183
2184 return true;
2185 }
2186
2187 public function makeList( $a, $mode = self::LIST_COMMA ) {
2188 if ( !is_array( $a ) ) {
2189 throw new DBUnexpectedError( $this, __METHOD__ . ' called with incorrect parameters' );
2190 }
2191
2192 $first = true;
2193 $list = '';
2194
2195 foreach ( $a as $field => $value ) {
2196 if ( !$first ) {
2197 if ( $mode == self::LIST_AND ) {
2198 $list .= ' AND ';
2199 } elseif ( $mode == self::LIST_OR ) {
2200 $list .= ' OR ';
2201 } else {
2202 $list .= ',';
2203 }
2204 } else {
2205 $first = false;
2206 }
2207
2208 if ( ( $mode == self::LIST_AND || $mode == self::LIST_OR ) && is_numeric( $field ) ) {
2209 $list .= "($value)";
2210 } elseif ( $mode == self::LIST_SET && is_numeric( $field ) ) {
2211 $list .= "$value";
2212 } elseif (
2213 ( $mode == self::LIST_AND || $mode == self::LIST_OR ) && is_array( $value )
2214 ) {
2215 // Remove null from array to be handled separately if found
2216 $includeNull = false;
2217 foreach ( array_keys( $value, null, true ) as $nullKey ) {
2218 $includeNull = true;
2219 unset( $value[$nullKey] );
2220 }
2221 if ( count( $value ) == 0 && !$includeNull ) {
2222 throw new InvalidArgumentException(
2223 __METHOD__ . ": empty input for field $field" );
2224 } elseif ( count( $value ) == 0 ) {
2225 // only check if $field is null
2226 $list .= "$field IS NULL";
2227 } else {
2228 // IN clause contains at least one valid element
2229 if ( $includeNull ) {
2230 // Group subconditions to ensure correct precedence
2231 $list .= '(';
2232 }
2233 if ( count( $value ) == 1 ) {
2234 // Special-case single values, as IN isn't terribly efficient
2235 // Don't necessarily assume the single key is 0; we don't
2236 // enforce linear numeric ordering on other arrays here.
2237 $value = array_values( $value )[0];
2238 $list .= $field . " = " . $this->addQuotes( $value );
2239 } else {
2240 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
2241 }
2242 // if null present in array, append IS NULL
2243 if ( $includeNull ) {
2244 $list .= " OR $field IS NULL)";
2245 }
2246 }
2247 } elseif ( $value === null ) {
2248 if ( $mode == self::LIST_AND || $mode == self::LIST_OR ) {
2249 $list .= "$field IS ";
2250 } elseif ( $mode == self::LIST_SET ) {
2251 $list .= "$field = ";
2252 }
2253 $list .= 'NULL';
2254 } else {
2255 if (
2256 $mode == self::LIST_AND || $mode == self::LIST_OR || $mode == self::LIST_SET
2257 ) {
2258 $list .= "$field = ";
2259 }
2260 $list .= $mode == self::LIST_NAMES ? $value : $this->addQuotes( $value );
2261 }
2262 }
2263
2264 return $list;
2265 }
2266
2267 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
2268 $conds = [];
2269
2270 foreach ( $data as $base => $sub ) {
2271 if ( count( $sub ) ) {
2272 $conds[] = $this->makeList(
2273 [ $baseKey => $base, $subKey => array_keys( $sub ) ],
2274 self::LIST_AND );
2275 }
2276 }
2277
2278 if ( $conds ) {
2279 return $this->makeList( $conds, self::LIST_OR );
2280 } else {
2281 // Nothing to search for...
2282 return false;
2283 }
2284 }
2285
2286 public function aggregateValue( $valuedata, $valuename = 'value' ) {
2287 return $valuename;
2288 }
2289
2290 public function bitNot( $field ) {
2291 return "(~$field)";
2292 }
2293
2294 public function bitAnd( $fieldLeft, $fieldRight ) {
2295 return "($fieldLeft & $fieldRight)";
2296 }
2297
2298 public function bitOr( $fieldLeft, $fieldRight ) {
2299 return "($fieldLeft | $fieldRight)";
2300 }
2301
2302 public function buildConcat( $stringList ) {
2303 return 'CONCAT(' . implode( ',', $stringList ) . ')';
2304 }
2305
2306 public function buildGroupConcatField(
2307 $delim, $table, $field, $conds = '', $join_conds = []
2308 ) {
2309 $fld = "GROUP_CONCAT($field SEPARATOR " . $this->addQuotes( $delim ) . ')';
2310
2311 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
2312 }
2313
2314 public function buildSubstring( $input, $startPosition, $length = null ) {
2315 $this->assertBuildSubstringParams( $startPosition, $length );
2316 $functionBody = "$input FROM $startPosition";
2317 if ( $length !== null ) {
2318 $functionBody .= " FOR $length";
2319 }
2320 return 'SUBSTRING(' . $functionBody . ')';
2321 }
2322
2323 /**
2324 * Check type and bounds for parameters to self::buildSubstring()
2325 *
2326 * All supported databases have substring functions that behave the same for
2327 * positive $startPosition and non-negative $length, but behaviors differ when
2328 * given 0 or negative $startPosition or negative $length. The simplest
2329 * solution to that is to just forbid those values.
2330 *
2331 * @param int $startPosition
2332 * @param int|null $length
2333 * @since 1.31
2334 */
2335 protected function assertBuildSubstringParams( $startPosition, $length ) {
2336 if ( !is_int( $startPosition ) || $startPosition <= 0 ) {
2337 throw new InvalidArgumentException(
2338 '$startPosition must be a positive integer'
2339 );
2340 }
2341 if ( !( is_int( $length ) && $length >= 0 || $length === null ) ) {
2342 throw new InvalidArgumentException(
2343 '$length must be null or an integer greater than or equal to 0'
2344 );
2345 }
2346 }
2347
2348 public function buildStringCast( $field ) {
2349 // In theory this should work for any standards-compliant
2350 // SQL implementation, although it may not be the best way to do it.
2351 return "CAST( $field AS CHARACTER )";
2352 }
2353
2354 public function buildIntegerCast( $field ) {
2355 return 'CAST( ' . $field . ' AS INTEGER )';
2356 }
2357
2358 public function buildSelectSubquery(
2359 $table, $vars, $conds = '', $fname = __METHOD__,
2360 $options = [], $join_conds = []
2361 ) {
2362 return new Subquery(
2363 $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds )
2364 );
2365 }
2366
2367 public function databasesAreIndependent() {
2368 return false;
2369 }
2370
2371 final public function selectDB( $db ) {
2372 $this->selectDomain( new DatabaseDomain(
2373 $db,
2374 $this->currentDomain->getSchema(),
2375 $this->currentDomain->getTablePrefix()
2376 ) );
2377
2378 return true;
2379 }
2380
2381 final public function selectDomain( $domain ) {
2382 $this->doSelectDomain( DatabaseDomain::newFromId( $domain ) );
2383 }
2384
2385 /**
2386 * @param DatabaseDomain $domain
2387 * @throws DBConnectionError
2388 * @throws DBError
2389 * @since 1.32
2390 */
2391 protected function doSelectDomain( DatabaseDomain $domain ) {
2392 $this->currentDomain = $domain;
2393 }
2394
2395 public function getDBname() {
2396 return $this->currentDomain->getDatabase();
2397 }
2398
2399 public function getServer() {
2400 return $this->server;
2401 }
2402
2403 public function tableName( $name, $format = 'quoted' ) {
2404 if ( $name instanceof Subquery ) {
2405 throw new DBUnexpectedError(
2406 $this,
2407 __METHOD__ . ': got Subquery instance when expecting a string'
2408 );
2409 }
2410
2411 # Skip the entire process when we have a string quoted on both ends.
2412 # Note that we check the end so that we will still quote any use of
2413 # use of `database`.table. But won't break things if someone wants
2414 # to query a database table with a dot in the name.
2415 if ( $this->isQuotedIdentifier( $name ) ) {
2416 return $name;
2417 }
2418
2419 # Lets test for any bits of text that should never show up in a table
2420 # name. Basically anything like JOIN or ON which are actually part of
2421 # SQL queries, but may end up inside of the table value to combine
2422 # sql. Such as how the API is doing.
2423 # Note that we use a whitespace test rather than a \b test to avoid
2424 # any remote case where a word like on may be inside of a table name
2425 # surrounded by symbols which may be considered word breaks.
2426 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2427 $this->queryLogger->warning(
2428 __METHOD__ . ": use of subqueries is not supported this way",
2429 [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
2430 );
2431
2432 return $name;
2433 }
2434
2435 # Split database and table into proper variables.
2436 list( $database, $schema, $prefix, $table ) = $this->qualifiedTableComponents( $name );
2437
2438 # Quote $table and apply the prefix if not quoted.
2439 # $tableName might be empty if this is called from Database::replaceVars()
2440 $tableName = "{$prefix}{$table}";
2441 if ( $format === 'quoted'
2442 && !$this->isQuotedIdentifier( $tableName )
2443 && $tableName !== ''
2444 ) {
2445 $tableName = $this->addIdentifierQuotes( $tableName );
2446 }
2447
2448 # Quote $schema and $database and merge them with the table name if needed
2449 $tableName = $this->prependDatabaseOrSchema( $schema, $tableName, $format );
2450 $tableName = $this->prependDatabaseOrSchema( $database, $tableName, $format );
2451
2452 return $tableName;
2453 }
2454
2455 /**
2456 * Get the table components needed for a query given the currently selected database
2457 *
2458 * @param string $name Table name in the form of db.schema.table, db.table, or table
2459 * @return array (DB name or "" for default, schema name, table prefix, table name)
2460 */
2461 protected function qualifiedTableComponents( $name ) {
2462 # We reverse the explode so that database.table and table both output the correct table.
2463 $dbDetails = explode( '.', $name, 3 );
2464 if ( count( $dbDetails ) == 3 ) {
2465 list( $database, $schema, $table ) = $dbDetails;
2466 # We don't want any prefix added in this case
2467 $prefix = '';
2468 } elseif ( count( $dbDetails ) == 2 ) {
2469 list( $database, $table ) = $dbDetails;
2470 # We don't want any prefix added in this case
2471 $prefix = '';
2472 # In dbs that support it, $database may actually be the schema
2473 # but that doesn't affect any of the functionality here
2474 $schema = '';
2475 } else {
2476 list( $table ) = $dbDetails;
2477 if ( isset( $this->tableAliases[$table] ) ) {
2478 $database = $this->tableAliases[$table]['dbname'];
2479 $schema = is_string( $this->tableAliases[$table]['schema'] )
2480 ? $this->tableAliases[$table]['schema']
2481 : $this->relationSchemaQualifier();
2482 $prefix = is_string( $this->tableAliases[$table]['prefix'] )
2483 ? $this->tableAliases[$table]['prefix']
2484 : $this->tablePrefix();
2485 } else {
2486 $database = '';
2487 $schema = $this->relationSchemaQualifier(); # Default schema
2488 $prefix = $this->tablePrefix(); # Default prefix
2489 }
2490 }
2491
2492 return [ $database, $schema, $prefix, $table ];
2493 }
2494
2495 /**
2496 * @param string|null $namespace Database or schema
2497 * @param string $relation Name of table, view, sequence, etc...
2498 * @param string $format One of (raw, quoted)
2499 * @return string Relation name with quoted and merged $namespace as needed
2500 */
2501 private function prependDatabaseOrSchema( $namespace, $relation, $format ) {
2502 if ( strlen( $namespace ) ) {
2503 if ( $format === 'quoted' && !$this->isQuotedIdentifier( $namespace ) ) {
2504 $namespace = $this->addIdentifierQuotes( $namespace );
2505 }
2506 $relation = $namespace . '.' . $relation;
2507 }
2508
2509 return $relation;
2510 }
2511
2512 public function tableNames() {
2513 $inArray = func_get_args();
2514 $retVal = [];
2515
2516 foreach ( $inArray as $name ) {
2517 $retVal[$name] = $this->tableName( $name );
2518 }
2519
2520 return $retVal;
2521 }
2522
2523 public function tableNamesN() {
2524 $inArray = func_get_args();
2525 $retVal = [];
2526
2527 foreach ( $inArray as $name ) {
2528 $retVal[] = $this->tableName( $name );
2529 }
2530
2531 return $retVal;
2532 }
2533
2534 /**
2535 * Get an aliased table name
2536 *
2537 * This returns strings like "tableName AS newTableName" for aliased tables
2538 * and "(SELECT * from tableA) newTablename" for subqueries (e.g. derived tables)
2539 *
2540 * @see Database::tableName()
2541 * @param string|Subquery $table Table name or object with a 'sql' field
2542 * @param string|bool $alias Table alias (optional)
2543 * @return string SQL name for aliased table. Will not alias a table to its own name
2544 */
2545 protected function tableNameWithAlias( $table, $alias = false ) {
2546 if ( is_string( $table ) ) {
2547 $quotedTable = $this->tableName( $table );
2548 } elseif ( $table instanceof Subquery ) {
2549 $quotedTable = (string)$table;
2550 } else {
2551 throw new InvalidArgumentException( "Table must be a string or Subquery" );
2552 }
2553
2554 if ( $alias === false || $alias === $table ) {
2555 if ( $table instanceof Subquery ) {
2556 throw new InvalidArgumentException( "Subquery table missing alias" );
2557 }
2558
2559 return $quotedTable;
2560 } else {
2561 return $quotedTable . ' ' . $this->addIdentifierQuotes( $alias );
2562 }
2563 }
2564
2565 /**
2566 * Gets an array of aliased table names
2567 *
2568 * @param array $tables [ [alias] => table ]
2569 * @return string[] See tableNameWithAlias()
2570 */
2571 protected function tableNamesWithAlias( $tables ) {
2572 $retval = [];
2573 foreach ( $tables as $alias => $table ) {
2574 if ( is_numeric( $alias ) ) {
2575 $alias = $table;
2576 }
2577 $retval[] = $this->tableNameWithAlias( $table, $alias );
2578 }
2579
2580 return $retval;
2581 }
2582
2583 /**
2584 * Get an aliased field name
2585 * e.g. fieldName AS newFieldName
2586 *
2587 * @param string $name Field name
2588 * @param string|bool $alias Alias (optional)
2589 * @return string SQL name for aliased field. Will not alias a field to its own name
2590 */
2591 protected function fieldNameWithAlias( $name, $alias = false ) {
2592 if ( !$alias || (string)$alias === (string)$name ) {
2593 return $name;
2594 } else {
2595 return $name . ' AS ' . $this->addIdentifierQuotes( $alias ); // PostgreSQL needs AS
2596 }
2597 }
2598
2599 /**
2600 * Gets an array of aliased field names
2601 *
2602 * @param array $fields [ [alias] => field ]
2603 * @return string[] See fieldNameWithAlias()
2604 */
2605 protected function fieldNamesWithAlias( $fields ) {
2606 $retval = [];
2607 foreach ( $fields as $alias => $field ) {
2608 if ( is_numeric( $alias ) ) {
2609 $alias = $field;
2610 }
2611 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2612 }
2613
2614 return $retval;
2615 }
2616
2617 /**
2618 * Get the aliased table name clause for a FROM clause
2619 * which might have a JOIN and/or USE INDEX or IGNORE INDEX clause
2620 *
2621 * @param array $tables ( [alias] => table )
2622 * @param array $use_index Same as for select()
2623 * @param array $ignore_index Same as for select()
2624 * @param array $join_conds Same as for select()
2625 * @return string
2626 */
2627 protected function tableNamesWithIndexClauseOrJOIN(
2628 $tables, $use_index = [], $ignore_index = [], $join_conds = []
2629 ) {
2630 $ret = [];
2631 $retJOIN = [];
2632 $use_index = (array)$use_index;
2633 $ignore_index = (array)$ignore_index;
2634 $join_conds = (array)$join_conds;
2635
2636 foreach ( $tables as $alias => $table ) {
2637 if ( !is_string( $alias ) ) {
2638 // No alias? Set it equal to the table name
2639 $alias = $table;
2640 }
2641
2642 if ( is_array( $table ) ) {
2643 // A parenthesized group
2644 if ( count( $table ) > 1 ) {
2645 $joinedTable = '(' .
2646 $this->tableNamesWithIndexClauseOrJOIN(
2647 $table, $use_index, $ignore_index, $join_conds ) . ')';
2648 } else {
2649 // Degenerate case
2650 $innerTable = reset( $table );
2651 $innerAlias = key( $table );
2652 $joinedTable = $this->tableNameWithAlias(
2653 $innerTable,
2654 is_string( $innerAlias ) ? $innerAlias : $innerTable
2655 );
2656 }
2657 } else {
2658 $joinedTable = $this->tableNameWithAlias( $table, $alias );
2659 }
2660
2661 // Is there a JOIN clause for this table?
2662 if ( isset( $join_conds[$alias] ) ) {
2663 list( $joinType, $conds ) = $join_conds[$alias];
2664 $tableClause = $joinType;
2665 $tableClause .= ' ' . $joinedTable;
2666 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2667 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2668 if ( $use != '' ) {
2669 $tableClause .= ' ' . $use;
2670 }
2671 }
2672 if ( isset( $ignore_index[$alias] ) ) { // has IGNORE INDEX?
2673 $ignore = $this->ignoreIndexClause(
2674 implode( ',', (array)$ignore_index[$alias] ) );
2675 if ( $ignore != '' ) {
2676 $tableClause .= ' ' . $ignore;
2677 }
2678 }
2679 $on = $this->makeList( (array)$conds, self::LIST_AND );
2680 if ( $on != '' ) {
2681 $tableClause .= ' ON (' . $on . ')';
2682 }
2683
2684 $retJOIN[] = $tableClause;
2685 } elseif ( isset( $use_index[$alias] ) ) {
2686 // Is there an INDEX clause for this table?
2687 $tableClause = $joinedTable;
2688 $tableClause .= ' ' . $this->useIndexClause(
2689 implode( ',', (array)$use_index[$alias] )
2690 );
2691
2692 $ret[] = $tableClause;
2693 } elseif ( isset( $ignore_index[$alias] ) ) {
2694 // Is there an INDEX clause for this table?
2695 $tableClause = $joinedTable;
2696 $tableClause .= ' ' . $this->ignoreIndexClause(
2697 implode( ',', (array)$ignore_index[$alias] )
2698 );
2699
2700 $ret[] = $tableClause;
2701 } else {
2702 $tableClause = $joinedTable;
2703
2704 $ret[] = $tableClause;
2705 }
2706 }
2707
2708 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2709 $implicitJoins = implode( ',', $ret );
2710 $explicitJoins = implode( ' ', $retJOIN );
2711
2712 // Compile our final table clause
2713 return implode( ' ', [ $implicitJoins, $explicitJoins ] );
2714 }
2715
2716 /**
2717 * Allows for index remapping in queries where this is not consistent across DBMS
2718 *
2719 * @param string $index
2720 * @return string
2721 */
2722 protected function indexName( $index ) {
2723 return $this->indexAliases[$index] ?? $index;
2724 }
2725
2726 public function addQuotes( $s ) {
2727 if ( $s instanceof Blob ) {
2728 $s = $s->fetch();
2729 }
2730 if ( $s === null ) {
2731 return 'NULL';
2732 } elseif ( is_bool( $s ) ) {
2733 return (int)$s;
2734 } else {
2735 # This will also quote numeric values. This should be harmless,
2736 # and protects against weird problems that occur when they really
2737 # _are_ strings such as article titles and string->number->string
2738 # conversion is not 1:1.
2739 return "'" . $this->strencode( $s ) . "'";
2740 }
2741 }
2742
2743 public function addIdentifierQuotes( $s ) {
2744 return '"' . str_replace( '"', '""', $s ) . '"';
2745 }
2746
2747 /**
2748 * Returns if the given identifier looks quoted or not according to
2749 * the database convention for quoting identifiers .
2750 *
2751 * @note Do not use this to determine if untrusted input is safe.
2752 * A malicious user can trick this function.
2753 * @param string $name
2754 * @return bool
2755 */
2756 public function isQuotedIdentifier( $name ) {
2757 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2758 }
2759
2760 /**
2761 * @param string $s
2762 * @param string $escapeChar
2763 * @return string
2764 */
2765 protected function escapeLikeInternal( $s, $escapeChar = '`' ) {
2766 return str_replace( [ $escapeChar, '%', '_' ],
2767 [ "{$escapeChar}{$escapeChar}", "{$escapeChar}%", "{$escapeChar}_" ],
2768 $s );
2769 }
2770
2771 public function buildLike( $param, ...$params ) {
2772 if ( is_array( $param ) ) {
2773 $params = $param;
2774 } else {
2775 $params = func_get_args();
2776 }
2777
2778 $s = '';
2779
2780 // We use ` instead of \ as the default LIKE escape character, since addQuotes()
2781 // may escape backslashes, creating problems of double escaping. The `
2782 // character has good cross-DBMS compatibility, avoiding special operators
2783 // in MS SQL like ^ and %
2784 $escapeChar = '`';
2785
2786 foreach ( $params as $value ) {
2787 if ( $value instanceof LikeMatch ) {
2788 $s .= $value->toString();
2789 } else {
2790 $s .= $this->escapeLikeInternal( $value, $escapeChar );
2791 }
2792 }
2793
2794 return ' LIKE ' .
2795 $this->addQuotes( $s ) . ' ESCAPE ' . $this->addQuotes( $escapeChar ) . ' ';
2796 }
2797
2798 public function anyChar() {
2799 return new LikeMatch( '_' );
2800 }
2801
2802 public function anyString() {
2803 return new LikeMatch( '%' );
2804 }
2805
2806 public function nextSequenceValue( $seqName ) {
2807 return null;
2808 }
2809
2810 /**
2811 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2812 * is only needed because a) MySQL must be as efficient as possible due to
2813 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2814 * which index to pick. Anyway, other databases might have different
2815 * indexes on a given table. So don't bother overriding this unless you're
2816 * MySQL.
2817 * @param string $index
2818 * @return string
2819 */
2820 public function useIndexClause( $index ) {
2821 return '';
2822 }
2823
2824 /**
2825 * IGNORE INDEX clause. Unlikely to be useful for anything but MySQL. This
2826 * is only needed because a) MySQL must be as efficient as possible due to
2827 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2828 * which index to pick. Anyway, other databases might have different
2829 * indexes on a given table. So don't bother overriding this unless you're
2830 * MySQL.
2831 * @param string $index
2832 * @return string
2833 */
2834 public function ignoreIndexClause( $index ) {
2835 return '';
2836 }
2837
2838 public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
2839 if ( count( $rows ) == 0 ) {
2840 return;
2841 }
2842
2843 $uniqueIndexes = (array)$uniqueIndexes;
2844 // Single row case
2845 if ( !is_array( reset( $rows ) ) ) {
2846 $rows = [ $rows ];
2847 }
2848
2849 try {
2850 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
2851 $affectedRowCount = 0;
2852 foreach ( $rows as $row ) {
2853 // Delete rows which collide with this one
2854 $indexWhereClauses = [];
2855 foreach ( $uniqueIndexes as $index ) {
2856 $indexColumns = (array)$index;
2857 $indexRowValues = array_intersect_key( $row, array_flip( $indexColumns ) );
2858 if ( count( $indexRowValues ) != count( $indexColumns ) ) {
2859 throw new DBUnexpectedError(
2860 $this,
2861 'New record does not provide all values for unique key (' .
2862 implode( ', ', $indexColumns ) . ')'
2863 );
2864 } elseif ( in_array( null, $indexRowValues, true ) ) {
2865 throw new DBUnexpectedError(
2866 $this,
2867 'New record has a null value for unique key (' .
2868 implode( ', ', $indexColumns ) . ')'
2869 );
2870 }
2871 $indexWhereClauses[] = $this->makeList( $indexRowValues, LIST_AND );
2872 }
2873
2874 if ( $indexWhereClauses ) {
2875 $this->delete( $table, $this->makeList( $indexWhereClauses, LIST_OR ), $fname );
2876 $affectedRowCount += $this->affectedRows();
2877 }
2878
2879 // Now insert the row
2880 $this->insert( $table, $row, $fname );
2881 $affectedRowCount += $this->affectedRows();
2882 }
2883 $this->endAtomic( $fname );
2884 $this->affectedRowCount = $affectedRowCount;
2885 } catch ( Exception $e ) {
2886 $this->cancelAtomic( $fname );
2887 throw $e;
2888 }
2889 }
2890
2891 /**
2892 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2893 * statement.
2894 *
2895 * @param string $table Table name
2896 * @param array|string $rows Row(s) to insert
2897 * @param string $fname Caller function name
2898 */
2899 protected function nativeReplace( $table, $rows, $fname ) {
2900 $table = $this->tableName( $table );
2901
2902 # Single row case
2903 if ( !is_array( reset( $rows ) ) ) {
2904 $rows = [ $rows ];
2905 }
2906
2907 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2908 $first = true;
2909
2910 foreach ( $rows as $row ) {
2911 if ( $first ) {
2912 $first = false;
2913 } else {
2914 $sql .= ',';
2915 }
2916
2917 $sql .= '(' . $this->makeList( $row ) . ')';
2918 }
2919
2920 $this->query( $sql, $fname );
2921 }
2922
2923 public function upsert( $table, array $rows, $uniqueIndexes, array $set,
2924 $fname = __METHOD__
2925 ) {
2926 if ( $rows === [] ) {
2927 return true; // nothing to do
2928 }
2929
2930 $uniqueIndexes = (array)$uniqueIndexes;
2931 if ( !is_array( reset( $rows ) ) ) {
2932 $rows = [ $rows ];
2933 }
2934
2935 if ( count( $uniqueIndexes ) ) {
2936 $clauses = []; // list WHERE clauses that each identify a single row
2937 foreach ( $rows as $row ) {
2938 foreach ( $uniqueIndexes as $index ) {
2939 $index = is_array( $index ) ? $index : [ $index ]; // columns
2940 $rowKey = []; // unique key to this row
2941 foreach ( $index as $column ) {
2942 $rowKey[$column] = $row[$column];
2943 }
2944 $clauses[] = $this->makeList( $rowKey, self::LIST_AND );
2945 }
2946 }
2947 $where = [ $this->makeList( $clauses, self::LIST_OR ) ];
2948 } else {
2949 $where = false;
2950 }
2951
2952 $affectedRowCount = 0;
2953 try {
2954 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
2955 # Update any existing conflicting row(s)
2956 if ( $where !== false ) {
2957 $this->update( $table, $set, $where, $fname );
2958 $affectedRowCount += $this->affectedRows();
2959 }
2960 # Now insert any non-conflicting row(s)
2961 $this->insert( $table, $rows, $fname, [ 'IGNORE' ] );
2962 $affectedRowCount += $this->affectedRows();
2963 $this->endAtomic( $fname );
2964 $this->affectedRowCount = $affectedRowCount;
2965 } catch ( Exception $e ) {
2966 $this->cancelAtomic( $fname );
2967 throw $e;
2968 }
2969
2970 return true;
2971 }
2972
2973 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2974 $fname = __METHOD__
2975 ) {
2976 if ( !$conds ) {
2977 throw new DBUnexpectedError( $this, __METHOD__ . ' called with empty $conds' );
2978 }
2979
2980 $delTable = $this->tableName( $delTable );
2981 $joinTable = $this->tableName( $joinTable );
2982 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2983 if ( $conds != '*' ) {
2984 $sql .= 'WHERE ' . $this->makeList( $conds, self::LIST_AND );
2985 }
2986 $sql .= ')';
2987
2988 $this->query( $sql, $fname );
2989 }
2990
2991 public function textFieldSize( $table, $field ) {
2992 $table = $this->tableName( $table );
2993 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\"";
2994 $res = $this->query( $sql, __METHOD__ );
2995 $row = $this->fetchObject( $res );
2996
2997 $m = [];
2998
2999 if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
3000 $size = $m[1];
3001 } else {
3002 $size = -1;
3003 }
3004
3005 return $size;
3006 }
3007
3008 public function delete( $table, $conds, $fname = __METHOD__ ) {
3009 if ( !$conds ) {
3010 throw new DBUnexpectedError( $this, __METHOD__ . ' called with no conditions' );
3011 }
3012
3013 $table = $this->tableName( $table );
3014 $sql = "DELETE FROM $table";
3015
3016 if ( $conds != '*' ) {
3017 if ( is_array( $conds ) ) {
3018 $conds = $this->makeList( $conds, self::LIST_AND );
3019 }
3020 $sql .= ' WHERE ' . $conds;
3021 }
3022
3023 $this->query( $sql, $fname );
3024
3025 return true;
3026 }
3027
3028 final public function insertSelect(
3029 $destTable, $srcTable, $varMap, $conds,
3030 $fname = __METHOD__, $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3031 ) {
3032 static $hints = [ 'NO_AUTO_COLUMNS' ];
3033
3034 $insertOptions = (array)$insertOptions;
3035 $selectOptions = (array)$selectOptions;
3036
3037 if ( $this->cliMode && $this->isInsertSelectSafe( $insertOptions, $selectOptions ) ) {
3038 // For massive migrations with downtime, we don't want to select everything
3039 // into memory and OOM, so do all this native on the server side if possible.
3040 $this->nativeInsertSelect(
3041 $destTable,
3042 $srcTable,
3043 $varMap,
3044 $conds,
3045 $fname,
3046 array_diff( $insertOptions, $hints ),
3047 $selectOptions,
3048 $selectJoinConds
3049 );
3050 } else {
3051 $this->nonNativeInsertSelect(
3052 $destTable,
3053 $srcTable,
3054 $varMap,
3055 $conds,
3056 $fname,
3057 array_diff( $insertOptions, $hints ),
3058 $selectOptions,
3059 $selectJoinConds
3060 );
3061 }
3062
3063 return true;
3064 }
3065
3066 /**
3067 * @param array $insertOptions INSERT options
3068 * @param array $selectOptions SELECT options
3069 * @return bool Whether an INSERT SELECT with these options will be replication safe
3070 * @since 1.31
3071 */
3072 protected function isInsertSelectSafe( array $insertOptions, array $selectOptions ) {
3073 return true;
3074 }
3075
3076 /**
3077 * Implementation of insertSelect() based on select() and insert()
3078 *
3079 * @see IDatabase::insertSelect()
3080 * @since 1.30
3081 * @param string $destTable
3082 * @param string|array $srcTable
3083 * @param array $varMap
3084 * @param array $conds
3085 * @param string $fname
3086 * @param array $insertOptions
3087 * @param array $selectOptions
3088 * @param array $selectJoinConds
3089 */
3090 protected function nonNativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
3091 $fname = __METHOD__,
3092 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3093 ) {
3094 // For web requests, do a locking SELECT and then INSERT. This puts the SELECT burden
3095 // on only the master (without needing row-based-replication). It also makes it easy to
3096 // know how big the INSERT is going to be.
3097 $fields = [];
3098 foreach ( $varMap as $dstColumn => $sourceColumnOrSql ) {
3099 $fields[] = $this->fieldNameWithAlias( $sourceColumnOrSql, $dstColumn );
3100 }
3101 $selectOptions[] = 'FOR UPDATE';
3102 $res = $this->select(
3103 $srcTable, implode( ',', $fields ), $conds, $fname, $selectOptions, $selectJoinConds
3104 );
3105 if ( !$res ) {
3106 return;
3107 }
3108
3109 try {
3110 $affectedRowCount = 0;
3111 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
3112 $rows = [];
3113 $ok = true;
3114 foreach ( $res as $row ) {
3115 $rows[] = (array)$row;
3116
3117 // Avoid inserts that are too huge
3118 if ( count( $rows ) >= $this->nonNativeInsertSelectBatchSize ) {
3119 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
3120 if ( !$ok ) {
3121 break;
3122 }
3123 $affectedRowCount += $this->affectedRows();
3124 $rows = [];
3125 }
3126 }
3127 if ( $rows && $ok ) {
3128 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
3129 if ( $ok ) {
3130 $affectedRowCount += $this->affectedRows();
3131 }
3132 }
3133 if ( $ok ) {
3134 $this->endAtomic( $fname );
3135 $this->affectedRowCount = $affectedRowCount;
3136 } else {
3137 $this->cancelAtomic( $fname );
3138 }
3139 } catch ( Exception $e ) {
3140 $this->cancelAtomic( $fname );
3141 throw $e;
3142 }
3143 }
3144
3145 /**
3146 * Native server-side implementation of insertSelect() for situations where
3147 * we don't want to select everything into memory
3148 *
3149 * @see IDatabase::insertSelect()
3150 * @param string $destTable
3151 * @param string|array $srcTable
3152 * @param array $varMap
3153 * @param array $conds
3154 * @param string $fname
3155 * @param array $insertOptions
3156 * @param array $selectOptions
3157 * @param array $selectJoinConds
3158 */
3159 protected function nativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
3160 $fname = __METHOD__,
3161 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3162 ) {
3163 $destTable = $this->tableName( $destTable );
3164
3165 if ( !is_array( $insertOptions ) ) {
3166 $insertOptions = [ $insertOptions ];
3167 }
3168
3169 $insertOptions = $this->makeInsertOptions( $insertOptions );
3170
3171 $selectSql = $this->selectSQLText(
3172 $srcTable,
3173 array_values( $varMap ),
3174 $conds,
3175 $fname,
3176 $selectOptions,
3177 $selectJoinConds
3178 );
3179
3180 $sql = "INSERT $insertOptions" .
3181 " INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ') ' .
3182 $selectSql;
3183
3184 $this->query( $sql, $fname );
3185 }
3186
3187 public function limitResult( $sql, $limit, $offset = false ) {
3188 if ( !is_numeric( $limit ) ) {
3189 throw new DBUnexpectedError(
3190 $this,
3191 "Invalid non-numeric limit passed to " . __METHOD__
3192 );
3193 }
3194 // This version works in MySQL and SQLite. It will very likely need to be
3195 // overridden for most other RDBMS subclasses.
3196 return "$sql LIMIT "
3197 . ( ( is_numeric( $offset ) && $offset != 0 ) ? "{$offset}," : "" )
3198 . "{$limit} ";
3199 }
3200
3201 public function unionSupportsOrderAndLimit() {
3202 return true; // True for almost every DB supported
3203 }
3204
3205 public function unionQueries( $sqls, $all ) {
3206 $glue = $all ? ') UNION ALL (' : ') UNION (';
3207
3208 return '(' . implode( $glue, $sqls ) . ')';
3209 }
3210
3211 public function unionConditionPermutations(
3212 $table, $vars, array $permute_conds, $extra_conds = '', $fname = __METHOD__,
3213 $options = [], $join_conds = []
3214 ) {
3215 // First, build the Cartesian product of $permute_conds
3216 $conds = [ [] ];
3217 foreach ( $permute_conds as $field => $values ) {
3218 if ( !$values ) {
3219 // Skip empty $values
3220 continue;
3221 }
3222 $values = array_unique( $values ); // For sanity
3223 $newConds = [];
3224 foreach ( $conds as $cond ) {
3225 foreach ( $values as $value ) {
3226 $cond[$field] = $value;
3227 $newConds[] = $cond; // Arrays are by-value, not by-reference, so this works
3228 }
3229 }
3230 $conds = $newConds;
3231 }
3232
3233 $extra_conds = $extra_conds === '' ? [] : (array)$extra_conds;
3234
3235 // If there's just one condition and no subordering, hand off to
3236 // selectSQLText directly.
3237 if ( count( $conds ) === 1 &&
3238 ( !isset( $options['INNER ORDER BY'] ) || !$this->unionSupportsOrderAndLimit() )
3239 ) {
3240 return $this->selectSQLText(
3241 $table, $vars, $conds[0] + $extra_conds, $fname, $options, $join_conds
3242 );
3243 }
3244
3245 // Otherwise, we need to pull out the order and limit to apply after
3246 // the union. Then build the SQL queries for each set of conditions in
3247 // $conds. Then union them together (using UNION ALL, because the
3248 // product *should* already be distinct).
3249 $orderBy = $this->makeOrderBy( $options );
3250 $limit = $options['LIMIT'] ?? null;
3251 $offset = $options['OFFSET'] ?? false;
3252 $all = empty( $options['NOTALL'] ) && !in_array( 'NOTALL', $options );
3253 if ( !$this->unionSupportsOrderAndLimit() ) {
3254 unset( $options['ORDER BY'], $options['LIMIT'], $options['OFFSET'] );
3255 } else {
3256 if ( array_key_exists( 'INNER ORDER BY', $options ) ) {
3257 $options['ORDER BY'] = $options['INNER ORDER BY'];
3258 }
3259 if ( $limit !== null && is_numeric( $offset ) && $offset != 0 ) {
3260 // We need to increase the limit by the offset rather than
3261 // using the offset directly, otherwise it'll skip incorrectly
3262 // in the subqueries.
3263 $options['LIMIT'] = $limit + $offset;
3264 unset( $options['OFFSET'] );
3265 }
3266 }
3267
3268 $sqls = [];
3269 foreach ( $conds as $cond ) {
3270 $sqls[] = $this->selectSQLText(
3271 $table, $vars, $cond + $extra_conds, $fname, $options, $join_conds
3272 );
3273 }
3274 $sql = $this->unionQueries( $sqls, $all ) . $orderBy;
3275 if ( $limit !== null ) {
3276 $sql = $this->limitResult( $sql, $limit, $offset );
3277 }
3278
3279 return $sql;
3280 }
3281
3282 public function conditional( $cond, $trueVal, $falseVal ) {
3283 if ( is_array( $cond ) ) {
3284 $cond = $this->makeList( $cond, self::LIST_AND );
3285 }
3286
3287 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
3288 }
3289
3290 public function strreplace( $orig, $old, $new ) {
3291 return "REPLACE({$orig}, {$old}, {$new})";
3292 }
3293
3294 public function getServerUptime() {
3295 return 0;
3296 }
3297
3298 public function wasDeadlock() {
3299 return false;
3300 }
3301
3302 public function wasLockTimeout() {
3303 return false;
3304 }
3305
3306 public function wasConnectionLoss() {
3307 return $this->wasConnectionError( $this->lastErrno() );
3308 }
3309
3310 public function wasReadOnlyError() {
3311 return false;
3312 }
3313
3314 public function wasErrorReissuable() {
3315 return (
3316 $this->wasDeadlock() ||
3317 $this->wasLockTimeout() ||
3318 $this->wasConnectionLoss()
3319 );
3320 }
3321
3322 /**
3323 * Do not use this method outside of Database/DBError classes
3324 *
3325 * @param int|string $errno
3326 * @return bool Whether the given query error was a connection drop
3327 */
3328 public function wasConnectionError( $errno ) {
3329 return false;
3330 }
3331
3332 /**
3333 * @return bool Whether it is known that the last query error only caused statement rollback
3334 * @note This is for backwards compatibility for callers catching DBError exceptions in
3335 * order to ignore problems like duplicate key errors or foriegn key violations
3336 * @since 1.31
3337 */
3338 protected function wasKnownStatementRollbackError() {
3339 return false; // don't know; it could have caused a transaction rollback
3340 }
3341
3342 public function deadlockLoop() {
3343 $args = func_get_args();
3344 $function = array_shift( $args );
3345 $tries = self::$DEADLOCK_TRIES;
3346
3347 $this->begin( __METHOD__ );
3348
3349 $retVal = null;
3350 /** @var Exception $e */
3351 $e = null;
3352 do {
3353 try {
3354 $retVal = $function( ...$args );
3355 break;
3356 } catch ( DBQueryError $e ) {
3357 if ( $this->wasDeadlock() ) {
3358 // Retry after a randomized delay
3359 usleep( mt_rand( self::$DEADLOCK_DELAY_MIN, self::$DEADLOCK_DELAY_MAX ) );
3360 } else {
3361 // Throw the error back up
3362 throw $e;
3363 }
3364 }
3365 } while ( --$tries > 0 );
3366
3367 if ( $tries <= 0 ) {
3368 // Too many deadlocks; give up
3369 $this->rollback( __METHOD__ );
3370 throw $e;
3371 } else {
3372 $this->commit( __METHOD__ );
3373
3374 return $retVal;
3375 }
3376 }
3377
3378 public function masterPosWait( DBMasterPos $pos, $timeout ) {
3379 # Real waits are implemented in the subclass.
3380 return 0;
3381 }
3382
3383 public function getReplicaPos() {
3384 # Stub
3385 return false;
3386 }
3387
3388 public function getMasterPos() {
3389 # Stub
3390 return false;
3391 }
3392
3393 public function serverIsReadOnly() {
3394 return false;
3395 }
3396
3397 final public function onTransactionResolution( callable $callback, $fname = __METHOD__ ) {
3398 if ( !$this->trxLevel() ) {
3399 throw new DBUnexpectedError( $this, "No transaction is active" );
3400 }
3401 $this->trxEndCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3402 }
3403
3404 final public function onTransactionCommitOrIdle( callable $callback, $fname = __METHOD__ ) {
3405 if ( !$this->trxLevel() && $this->getTransactionRoundId() ) {
3406 // Start an implicit transaction similar to how query() does
3407 $this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
3408 $this->trxAutomatic = true;
3409 }
3410
3411 $this->trxIdleCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3412 if ( !$this->trxLevel() ) {
3413 $this->runOnTransactionIdleCallbacks( self::TRIGGER_IDLE );
3414 }
3415 }
3416
3417 final public function onTransactionIdle( callable $callback, $fname = __METHOD__ ) {
3418 $this->onTransactionCommitOrIdle( $callback, $fname );
3419 }
3420
3421 final public function onTransactionPreCommitOrIdle( callable $callback, $fname = __METHOD__ ) {
3422 if ( !$this->trxLevel() && $this->getTransactionRoundId() ) {
3423 // Start an implicit transaction similar to how query() does
3424 $this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
3425 $this->trxAutomatic = true;
3426 }
3427
3428 if ( $this->trxLevel() ) {
3429 $this->trxPreCommitCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3430 } else {
3431 // No transaction is active nor will start implicitly, so make one for this callback
3432 $this->startAtomic( __METHOD__, self::ATOMIC_CANCELABLE );
3433 try {
3434 $callback( $this );
3435 $this->endAtomic( __METHOD__ );
3436 } catch ( Exception $e ) {
3437 $this->cancelAtomic( __METHOD__ );
3438 throw $e;
3439 }
3440 }
3441 }
3442
3443 final public function onAtomicSectionCancel( callable $callback, $fname = __METHOD__ ) {
3444 if ( !$this->trxLevel() || !$this->trxAtomicLevels ) {
3445 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)" );
3446 }
3447 $this->trxSectionCancelCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3448 }
3449
3450 /**
3451 * @return AtomicSectionIdentifier|null ID of the topmost atomic section level
3452 */
3453 private function currentAtomicSectionId() {
3454 if ( $this->trxLevel() && $this->trxAtomicLevels ) {
3455 $levelInfo = end( $this->trxAtomicLevels );
3456
3457 return $levelInfo[1];
3458 }
3459
3460 return null;
3461 }
3462
3463 /**
3464 * Hoist callback ownership for callbacks in a section to a parent section.
3465 * All callbacks should have an owner that is present in trxAtomicLevels.
3466 * @param AtomicSectionIdentifier $old
3467 * @param AtomicSectionIdentifier $new
3468 */
3469 private function reassignCallbacksForSection(
3470 AtomicSectionIdentifier $old, AtomicSectionIdentifier $new
3471 ) {
3472 foreach ( $this->trxPreCommitCallbacks as $key => $info ) {
3473 if ( $info[2] === $old ) {
3474 $this->trxPreCommitCallbacks[$key][2] = $new;
3475 }
3476 }
3477 foreach ( $this->trxIdleCallbacks as $key => $info ) {
3478 if ( $info[2] === $old ) {
3479 $this->trxIdleCallbacks[$key][2] = $new;
3480 }
3481 }
3482 foreach ( $this->trxEndCallbacks as $key => $info ) {
3483 if ( $info[2] === $old ) {
3484 $this->trxEndCallbacks[$key][2] = $new;
3485 }
3486 }
3487 foreach ( $this->trxSectionCancelCallbacks as $key => $info ) {
3488 if ( $info[2] === $old ) {
3489 $this->trxSectionCancelCallbacks[$key][2] = $new;
3490 }
3491 }
3492 }
3493
3494 /**
3495 * Update callbacks that were owned by cancelled atomic sections.
3496 *
3497 * Callbacks for "on commit" should never be run if they're owned by a
3498 * section that won't be committed.
3499 *
3500 * Callbacks for "on resolution" need to reflect that the section was
3501 * rolled back, even if the transaction as a whole commits successfully.
3502 *
3503 * Callbacks for "on section cancel" should already have been consumed,
3504 * but errors during the cancellation itself can prevent that while still
3505 * destroying the section. Hoist any such callbacks to the new top section,
3506 * which we assume will itself have to be cancelled or rolled back to
3507 * resolve the error.
3508 *
3509 * @param AtomicSectionIdentifier[] $sectionIds ID of an actual savepoint
3510 * @param AtomicSectionIdentifier|null $newSectionId New top section ID.
3511 * @throws UnexpectedValueException
3512 */
3513 private function modifyCallbacksForCancel(
3514 array $sectionIds, AtomicSectionIdentifier $newSectionId = null
3515 ) {
3516 // Cancel the "on commit" callbacks owned by this savepoint
3517 $this->trxIdleCallbacks = array_filter(
3518 $this->trxIdleCallbacks,
3519 function ( $entry ) use ( $sectionIds ) {
3520 return !in_array( $entry[2], $sectionIds, true );
3521 }
3522 );
3523 $this->trxPreCommitCallbacks = array_filter(
3524 $this->trxPreCommitCallbacks,
3525 function ( $entry ) use ( $sectionIds ) {
3526 return !in_array( $entry[2], $sectionIds, true );
3527 }
3528 );
3529 // Make "on resolution" callbacks owned by this savepoint to perceive a rollback
3530 foreach ( $this->trxEndCallbacks as $key => $entry ) {
3531 if ( in_array( $entry[2], $sectionIds, true ) ) {
3532 $callback = $entry[0];
3533 $this->trxEndCallbacks[$key][0] = function () use ( $callback ) {
3534 // @phan-suppress-next-line PhanInfiniteRecursion, PhanUndeclaredInvokeInCallable
3535 return $callback( self::TRIGGER_ROLLBACK, $this );
3536 };
3537 // This "on resolution" callback no longer belongs to a section.
3538 $this->trxEndCallbacks[$key][2] = null;
3539 }
3540 }
3541 // Hoist callback ownership for section cancel callbacks to the new top section
3542 foreach ( $this->trxSectionCancelCallbacks as $key => $entry ) {
3543 if ( in_array( $entry[2], $sectionIds, true ) ) {
3544 $this->trxSectionCancelCallbacks[$key][2] = $newSectionId;
3545 }
3546 }
3547 }
3548
3549 final public function setTransactionListener( $name, callable $callback = null ) {
3550 if ( $callback ) {
3551 $this->trxRecurringCallbacks[$name] = $callback;
3552 } else {
3553 unset( $this->trxRecurringCallbacks[$name] );
3554 }
3555 }
3556
3557 /**
3558 * Whether to disable running of post-COMMIT/ROLLBACK callbacks
3559 *
3560 * This method should not be used outside of Database/LoadBalancer
3561 *
3562 * @param bool $suppress
3563 * @since 1.28
3564 */
3565 final public function setTrxEndCallbackSuppression( $suppress ) {
3566 $this->trxEndCallbacksSuppressed = $suppress;
3567 }
3568
3569 /**
3570 * Actually consume and run any "on transaction idle/resolution" callbacks.
3571 *
3572 * This method should not be used outside of Database/LoadBalancer
3573 *
3574 * @param int $trigger IDatabase::TRIGGER_* constant
3575 * @return int Number of callbacks attempted
3576 * @since 1.20
3577 * @throws Exception
3578 */
3579 public function runOnTransactionIdleCallbacks( $trigger ) {
3580 if ( $this->trxLevel() ) { // sanity
3581 throw new DBUnexpectedError( $this, __METHOD__ . ': a transaction is still open' );
3582 }
3583
3584 if ( $this->trxEndCallbacksSuppressed ) {
3585 return 0;
3586 }
3587
3588 $count = 0;
3589 $autoTrx = $this->getFlag( self::DBO_TRX ); // automatic begin() enabled?
3590 /** @var Exception $e */
3591 $e = null; // first exception
3592 do { // callbacks may add callbacks :)
3593 $callbacks = array_merge(
3594 $this->trxIdleCallbacks,
3595 $this->trxEndCallbacks // include "transaction resolution" callbacks
3596 );
3597 $this->trxIdleCallbacks = []; // consumed (and recursion guard)
3598 $this->trxEndCallbacks = []; // consumed (recursion guard)
3599
3600 // Only run trxSectionCancelCallbacks on rollback, not commit.
3601 // But always consume them.
3602 if ( $trigger === self::TRIGGER_ROLLBACK ) {
3603 $callbacks = array_merge( $callbacks, $this->trxSectionCancelCallbacks );
3604 }
3605 $this->trxSectionCancelCallbacks = []; // consumed (recursion guard)
3606
3607 foreach ( $callbacks as $callback ) {
3608 ++$count;
3609 list( $phpCallback ) = $callback;
3610 $this->clearFlag( self::DBO_TRX ); // make each query its own transaction
3611 try {
3612 // @phan-suppress-next-line PhanParamTooManyCallable
3613 call_user_func( $phpCallback, $trigger, $this );
3614 } catch ( Exception $ex ) {
3615 call_user_func( $this->errorLogger, $ex );
3616 $e = $e ?: $ex;
3617 // Some callbacks may use startAtomic/endAtomic, so make sure
3618 // their transactions are ended so other callbacks don't fail
3619 if ( $this->trxLevel() ) {
3620 $this->rollback( __METHOD__, self::FLUSHING_INTERNAL );
3621 }
3622 } finally {
3623 if ( $autoTrx ) {
3624 $this->setFlag( self::DBO_TRX ); // restore automatic begin()
3625 } else {
3626 $this->clearFlag( self::DBO_TRX ); // restore auto-commit
3627 }
3628 }
3629 }
3630 } while ( count( $this->trxIdleCallbacks ) );
3631
3632 if ( $e instanceof Exception ) {
3633 throw $e; // re-throw any first exception
3634 }
3635
3636 return $count;
3637 }
3638
3639 /**
3640 * Actually consume and run any "on transaction pre-commit" callbacks.
3641 *
3642 * This method should not be used outside of Database/LoadBalancer
3643 *
3644 * @since 1.22
3645 * @return int Number of callbacks attempted
3646 * @throws Exception
3647 */
3648 public function runOnTransactionPreCommitCallbacks() {
3649 $count = 0;
3650
3651 $e = null; // first exception
3652 do { // callbacks may add callbacks :)
3653 $callbacks = $this->trxPreCommitCallbacks;
3654 $this->trxPreCommitCallbacks = []; // consumed (and recursion guard)
3655 foreach ( $callbacks as $callback ) {
3656 try {
3657 ++$count;
3658 list( $phpCallback ) = $callback;
3659 // @phan-suppress-next-line PhanUndeclaredInvokeInCallable
3660 $phpCallback( $this );
3661 } catch ( Exception $ex ) {
3662 ( $this->errorLogger )( $ex );
3663 $e = $e ?: $ex;
3664 }
3665 }
3666 } while ( count( $this->trxPreCommitCallbacks ) );
3667
3668 if ( $e instanceof Exception ) {
3669 throw $e; // re-throw any first exception
3670 }
3671
3672 return $count;
3673 }
3674
3675 /**
3676 * Actually run any "atomic section cancel" callbacks.
3677 *
3678 * @param int $trigger IDatabase::TRIGGER_* constant
3679 * @param AtomicSectionIdentifier[]|null $sectionIds Section IDs to cancel,
3680 * null on transaction rollback
3681 */
3682 private function runOnAtomicSectionCancelCallbacks(
3683 $trigger, array $sectionIds = null
3684 ) {
3685 /** @var Exception|Throwable $e */
3686 $e = null; // first exception
3687
3688 $notCancelled = [];
3689 do {
3690 $callbacks = $this->trxSectionCancelCallbacks;
3691 $this->trxSectionCancelCallbacks = []; // consumed (recursion guard)
3692 foreach ( $callbacks as $entry ) {
3693 if ( $sectionIds === null || in_array( $entry[2], $sectionIds, true ) ) {
3694 try {
3695 // @phan-suppress-next-line PhanUndeclaredInvokeInCallable
3696 $entry[0]( $trigger, $this );
3697 } catch ( Exception $ex ) {
3698 ( $this->errorLogger )( $ex );
3699 $e = $e ?: $ex;
3700 } catch ( Throwable $ex ) {
3701 // @todo: Log?
3702 $e = $e ?: $ex;
3703 }
3704 } else {
3705 $notCancelled[] = $entry;
3706 }
3707 }
3708 } while ( count( $this->trxSectionCancelCallbacks ) );
3709 $this->trxSectionCancelCallbacks = $notCancelled;
3710
3711 if ( $e !== null ) {
3712 throw $e; // re-throw any first Exception/Throwable
3713 }
3714 }
3715
3716 /**
3717 * Actually run any "transaction listener" callbacks.
3718 *
3719 * This method should not be used outside of Database/LoadBalancer
3720 *
3721 * @param int $trigger IDatabase::TRIGGER_* constant
3722 * @throws Exception
3723 * @since 1.20
3724 */
3725 public function runTransactionListenerCallbacks( $trigger ) {
3726 if ( $this->trxEndCallbacksSuppressed ) {
3727 return;
3728 }
3729
3730 /** @var Exception $e */
3731 $e = null; // first exception
3732
3733 foreach ( $this->trxRecurringCallbacks as $phpCallback ) {
3734 try {
3735 $phpCallback( $trigger, $this );
3736 } catch ( Exception $ex ) {
3737 ( $this->errorLogger )( $ex );
3738 $e = $e ?: $ex;
3739 }
3740 }
3741
3742 if ( $e instanceof Exception ) {
3743 throw $e; // re-throw any first exception
3744 }
3745 }
3746
3747 /**
3748 * Create a savepoint
3749 *
3750 * This is used internally to implement atomic sections. It should not be
3751 * used otherwise.
3752 *
3753 * @since 1.31
3754 * @param string $identifier Identifier for the savepoint
3755 * @param string $fname Calling function name
3756 */
3757 protected function doSavepoint( $identifier, $fname ) {
3758 $this->query( 'SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3759 }
3760
3761 /**
3762 * Release a savepoint
3763 *
3764 * This is used internally to implement atomic sections. It should not be
3765 * used otherwise.
3766 *
3767 * @since 1.31
3768 * @param string $identifier Identifier for the savepoint
3769 * @param string $fname Calling function name
3770 */
3771 protected function doReleaseSavepoint( $identifier, $fname ) {
3772 $this->query( 'RELEASE SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3773 }
3774
3775 /**
3776 * Rollback to a savepoint
3777 *
3778 * This is used internally to implement atomic sections. It should not be
3779 * used otherwise.
3780 *
3781 * @since 1.31
3782 * @param string $identifier Identifier for the savepoint
3783 * @param string $fname Calling function name
3784 */
3785 protected function doRollbackToSavepoint( $identifier, $fname ) {
3786 $this->query( 'ROLLBACK TO SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3787 }
3788
3789 /**
3790 * @param string $fname
3791 * @return string
3792 */
3793 private function nextSavepointId( $fname ) {
3794 $savepointId = self::$SAVEPOINT_PREFIX . ++$this->trxAtomicCounter;
3795 if ( strlen( $savepointId ) > 30 ) {
3796 // 30 == Oracle's identifier length limit (pre 12c)
3797 // With a 22 character prefix, that puts the highest number at 99999999.
3798 throw new DBUnexpectedError(
3799 $this,
3800 'There have been an excessively large number of atomic sections in a transaction'
3801 . " started by $this->trxFname (at $fname)"
3802 );
3803 }
3804
3805 return $savepointId;
3806 }
3807
3808 final public function startAtomic(
3809 $fname = __METHOD__, $cancelable = self::ATOMIC_NOT_CANCELABLE
3810 ) {
3811 $savepointId = $cancelable === self::ATOMIC_CANCELABLE ? self::$NOT_APPLICABLE : null;
3812
3813 if ( !$this->trxLevel() ) {
3814 $this->begin( $fname, self::TRANSACTION_INTERNAL ); // sets trxAutomatic
3815 // If DBO_TRX is set, a series of startAtomic/endAtomic pairs will result
3816 // in all changes being in one transaction to keep requests transactional.
3817 if ( $this->getFlag( self::DBO_TRX ) ) {
3818 // Since writes could happen in between the topmost atomic sections as part
3819 // of the transaction, those sections will need savepoints.
3820 $savepointId = $this->nextSavepointId( $fname );
3821 $this->doSavepoint( $savepointId, $fname );
3822 } else {
3823 $this->trxAutomaticAtomic = true;
3824 }
3825 } elseif ( $cancelable === self::ATOMIC_CANCELABLE ) {
3826 $savepointId = $this->nextSavepointId( $fname );
3827 $this->doSavepoint( $savepointId, $fname );
3828 }
3829
3830 $sectionId = new AtomicSectionIdentifier;
3831 $this->trxAtomicLevels[] = [ $fname, $sectionId, $savepointId ];
3832 $this->queryLogger->debug( 'startAtomic: entering level ' .
3833 ( count( $this->trxAtomicLevels ) - 1 ) . " ($fname)" );
3834
3835 return $sectionId;
3836 }
3837
3838 final public function endAtomic( $fname = __METHOD__ ) {
3839 if ( !$this->trxLevel() || !$this->trxAtomicLevels ) {
3840 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)" );
3841 }
3842
3843 // Check if the current section matches $fname
3844 $pos = count( $this->trxAtomicLevels ) - 1;
3845 list( $savedFname, $sectionId, $savepointId ) = $this->trxAtomicLevels[$pos];
3846 $this->queryLogger->debug( "endAtomic: leaving level $pos ($fname)" );
3847
3848 if ( $savedFname !== $fname ) {
3849 throw new DBUnexpectedError(
3850 $this,
3851 "Invalid atomic section ended (got $fname but expected $savedFname)"
3852 );
3853 }
3854
3855 // Remove the last section (no need to re-index the array)
3856 array_pop( $this->trxAtomicLevels );
3857
3858 if ( !$this->trxAtomicLevels && $this->trxAutomaticAtomic ) {
3859 $this->commit( $fname, self::FLUSHING_INTERNAL );
3860 } elseif ( $savepointId !== null && $savepointId !== self::$NOT_APPLICABLE ) {
3861 $this->doReleaseSavepoint( $savepointId, $fname );
3862 }
3863
3864 // Hoist callback ownership for callbacks in the section that just ended;
3865 // all callbacks should have an owner that is present in trxAtomicLevels.
3866 $currentSectionId = $this->currentAtomicSectionId();
3867 if ( $currentSectionId ) {
3868 $this->reassignCallbacksForSection( $sectionId, $currentSectionId );
3869 }
3870 }
3871
3872 final public function cancelAtomic(
3873 $fname = __METHOD__, AtomicSectionIdentifier $sectionId = null
3874 ) {
3875 if ( !$this->trxLevel() || !$this->trxAtomicLevels ) {
3876 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)" );
3877 }
3878
3879 $excisedIds = [];
3880 $newTopSection = $this->currentAtomicSectionId();
3881 try {
3882 $excisedFnames = [];
3883 if ( $sectionId !== null ) {
3884 // Find the (last) section with the given $sectionId
3885 $pos = -1;
3886 foreach ( $this->trxAtomicLevels as $i => list( $asFname, $asId, $spId ) ) {
3887 if ( $asId === $sectionId ) {
3888 $pos = $i;
3889 }
3890 }
3891 if ( $pos < 0 ) {
3892 throw new DBUnexpectedError( $this, "Atomic section not found (for $fname)" );
3893 }
3894 // Remove all descendant sections and re-index the array
3895 $len = count( $this->trxAtomicLevels );
3896 for ( $i = $pos + 1; $i < $len; ++$i ) {
3897 $excisedFnames[] = $this->trxAtomicLevels[$i][0];
3898 $excisedIds[] = $this->trxAtomicLevels[$i][1];
3899 }
3900 $this->trxAtomicLevels = array_slice( $this->trxAtomicLevels, 0, $pos + 1 );
3901 $newTopSection = $this->currentAtomicSectionId();
3902 }
3903
3904 // Check if the current section matches $fname
3905 $pos = count( $this->trxAtomicLevels ) - 1;
3906 list( $savedFname, $savedSectionId, $savepointId ) = $this->trxAtomicLevels[$pos];
3907
3908 if ( $excisedFnames ) {
3909 $this->queryLogger->debug( "cancelAtomic: canceling level $pos ($savedFname) " .
3910 "and descendants " . implode( ', ', $excisedFnames ) );
3911 } else {
3912 $this->queryLogger->debug( "cancelAtomic: canceling level $pos ($savedFname)" );
3913 }
3914
3915 if ( $savedFname !== $fname ) {
3916 throw new DBUnexpectedError(
3917 $this,
3918 "Invalid atomic section ended (got $fname but expected $savedFname)"
3919 );
3920 }
3921
3922 // Remove the last section (no need to re-index the array)
3923 array_pop( $this->trxAtomicLevels );
3924 $excisedIds[] = $savedSectionId;
3925 $newTopSection = $this->currentAtomicSectionId();
3926
3927 if ( $savepointId !== null ) {
3928 // Rollback the transaction to the state just before this atomic section
3929 if ( $savepointId === self::$NOT_APPLICABLE ) {
3930 $this->rollback( $fname, self::FLUSHING_INTERNAL );
3931 // Note: rollback() will run trxSectionCancelCallbacks
3932 } else {
3933 $this->doRollbackToSavepoint( $savepointId, $fname );
3934 $this->trxStatus = self::STATUS_TRX_OK; // no exception; recovered
3935 $this->trxStatusIgnoredCause = null;
3936
3937 // Run trxSectionCancelCallbacks now.
3938 $this->runOnAtomicSectionCancelCallbacks( self::TRIGGER_CANCEL, $excisedIds );
3939 }
3940 } elseif ( $this->trxStatus > self::STATUS_TRX_ERROR ) {
3941 // Put the transaction into an error state if it's not already in one
3942 $this->trxStatus = self::STATUS_TRX_ERROR;
3943 $this->trxStatusCause = new DBUnexpectedError(
3944 $this,
3945 "Uncancelable atomic section canceled (got $fname)"
3946 );
3947 }
3948 } finally {
3949 // Fix up callbacks owned by the sections that were just cancelled.
3950 // All callbacks should have an owner that is present in trxAtomicLevels.
3951 $this->modifyCallbacksForCancel( $excisedIds, $newTopSection );
3952 }
3953
3954 $this->affectedRowCount = 0; // for the sake of consistency
3955 }
3956
3957 final public function doAtomicSection(
3958 $fname, callable $callback, $cancelable = self::ATOMIC_NOT_CANCELABLE
3959 ) {
3960 $sectionId = $this->startAtomic( $fname, $cancelable );
3961 try {
3962 $res = $callback( $this, $fname );
3963 } catch ( Exception $e ) {
3964 $this->cancelAtomic( $fname, $sectionId );
3965
3966 throw $e;
3967 }
3968 $this->endAtomic( $fname );
3969
3970 return $res;
3971 }
3972
3973 final public function begin( $fname = __METHOD__, $mode = self::TRANSACTION_EXPLICIT ) {
3974 static $modes = [ self::TRANSACTION_EXPLICIT, self::TRANSACTION_INTERNAL ];
3975 if ( !in_array( $mode, $modes, true ) ) {
3976 throw new DBUnexpectedError( $this, "$fname: invalid mode parameter '$mode'" );
3977 }
3978
3979 // Protect against mismatched atomic section, transaction nesting, and snapshot loss
3980 if ( $this->trxLevel() ) {
3981 if ( $this->trxAtomicLevels ) {
3982 $levels = $this->flatAtomicSectionList();
3983 $msg = "$fname: Got explicit BEGIN while atomic section(s) $levels are open";
3984 throw new DBUnexpectedError( $this, $msg );
3985 } elseif ( !$this->trxAutomatic ) {
3986 $msg = "$fname: Explicit transaction already active (from {$this->trxFname})";
3987 throw new DBUnexpectedError( $this, $msg );
3988 } else {
3989 $msg = "$fname: Implicit transaction already active (from {$this->trxFname})";
3990 throw new DBUnexpectedError( $this, $msg );
3991 }
3992 } elseif ( $this->getFlag( self::DBO_TRX ) && $mode !== self::TRANSACTION_INTERNAL ) {
3993 $msg = "$fname: Implicit transaction expected (DBO_TRX set)";
3994 throw new DBUnexpectedError( $this, $msg );
3995 }
3996
3997 $this->assertHasConnectionHandle();
3998
3999 $this->doBegin( $fname );
4000 $this->trxShortId = sprintf( '%06x', mt_rand( 0, 0xffffff ) );
4001 $this->trxStatus = self::STATUS_TRX_OK;
4002 $this->trxStatusIgnoredCause = null;
4003 $this->trxAtomicCounter = 0;
4004 $this->trxTimestamp = microtime( true );
4005 $this->trxFname = $fname;
4006 $this->trxDoneWrites = false;
4007 $this->trxAutomaticAtomic = false;
4008 $this->trxAtomicLevels = [];
4009 $this->trxWriteDuration = 0.0;
4010 $this->trxWriteQueryCount = 0;
4011 $this->trxWriteAffectedRows = 0;
4012 $this->trxWriteAdjDuration = 0.0;
4013 $this->trxWriteAdjQueryCount = 0;
4014 $this->trxWriteCallers = [];
4015 // First SELECT after BEGIN will establish the snapshot in REPEATABLE-READ.
4016 // Get an estimate of the replication lag before any such queries.
4017 $this->trxReplicaLag = null; // clear cached value first
4018 $this->trxReplicaLag = $this->getApproximateLagStatus()['lag'];
4019 // T147697: make explicitTrxActive() return true until begin() finishes. This way, no
4020 // caller will think its OK to muck around with the transaction just because startAtomic()
4021 // has not yet completed (e.g. setting trxAtomicLevels).
4022 $this->trxAutomatic = ( $mode === self::TRANSACTION_INTERNAL );
4023 }
4024
4025 /**
4026 * Issues the BEGIN command to the database server.
4027 *
4028 * @see Database::begin()
4029 * @param string $fname
4030 * @throws DBError
4031 */
4032 protected function doBegin( $fname ) {
4033 $this->query( 'BEGIN', $fname );
4034 }
4035
4036 final public function commit( $fname = __METHOD__, $flush = self::FLUSHING_ONE ) {
4037 static $modes = [ self::FLUSHING_ONE, self::FLUSHING_ALL_PEERS, self::FLUSHING_INTERNAL ];
4038 if ( !in_array( $flush, $modes, true ) ) {
4039 throw new DBUnexpectedError( $this, "$fname: invalid flush parameter '$flush'" );
4040 }
4041
4042 if ( $this->trxLevel() && $this->trxAtomicLevels ) {
4043 // There are still atomic sections open; this cannot be ignored
4044 $levels = $this->flatAtomicSectionList();
4045 throw new DBUnexpectedError(
4046 $this,
4047 "$fname: Got COMMIT while atomic sections $levels are still open"
4048 );
4049 }
4050
4051 if ( $flush === self::FLUSHING_INTERNAL || $flush === self::FLUSHING_ALL_PEERS ) {
4052 if ( !$this->trxLevel() ) {
4053 return; // nothing to do
4054 } elseif ( !$this->trxAutomatic ) {
4055 throw new DBUnexpectedError(
4056 $this,
4057 "$fname: Flushing an explicit transaction, getting out of sync"
4058 );
4059 }
4060 } elseif ( !$this->trxLevel() ) {
4061 $this->queryLogger->error(
4062 "$fname: No transaction to commit, something got out of sync" );
4063 return; // nothing to do
4064 } elseif ( $this->trxAutomatic ) {
4065 throw new DBUnexpectedError(
4066 $this,
4067 "$fname: Expected mass commit of all peer transactions (DBO_TRX set)"
4068 );
4069 }
4070
4071 $this->assertHasConnectionHandle();
4072
4073 $this->runOnTransactionPreCommitCallbacks();
4074
4075 $writeTime = $this->pendingWriteQueryDuration( self::ESTIMATE_DB_APPLY );
4076 $this->doCommit( $fname );
4077 $oldTrxShortId = $this->consumeTrxShortId();
4078 $this->trxStatus = self::STATUS_TRX_NONE;
4079
4080 if ( $this->trxDoneWrites ) {
4081 $this->lastWriteTime = microtime( true );
4082 $this->trxProfiler->transactionWritingOut(
4083 $this->server,
4084 $this->getDomainID(),
4085 $oldTrxShortId,
4086 $writeTime,
4087 $this->trxWriteAffectedRows
4088 );
4089 }
4090
4091 // With FLUSHING_ALL_PEERS, callbacks will be explicitly run later
4092 if ( $flush !== self::FLUSHING_ALL_PEERS ) {
4093 $this->runOnTransactionIdleCallbacks( self::TRIGGER_COMMIT );
4094 $this->runTransactionListenerCallbacks( self::TRIGGER_COMMIT );
4095 }
4096 }
4097
4098 /**
4099 * Issues the COMMIT command to the database server.
4100 *
4101 * @see Database::commit()
4102 * @param string $fname
4103 * @throws DBError
4104 */
4105 protected function doCommit( $fname ) {
4106 if ( $this->trxLevel() ) {
4107 $this->query( 'COMMIT', $fname );
4108 }
4109 }
4110
4111 final public function rollback( $fname = __METHOD__, $flush = self::FLUSHING_ONE ) {
4112 $trxActive = $this->trxLevel();
4113
4114 if ( $flush !== self::FLUSHING_INTERNAL
4115 && $flush !== self::FLUSHING_ALL_PEERS
4116 && $this->getFlag( self::DBO_TRX )
4117 ) {
4118 throw new DBUnexpectedError(
4119 $this,
4120 "$fname: Expected mass rollback of all peer transactions (DBO_TRX set)"
4121 );
4122 }
4123
4124 if ( $trxActive ) {
4125 $this->assertHasConnectionHandle();
4126
4127 $this->doRollback( $fname );
4128 $oldTrxShortId = $this->consumeTrxShortId();
4129 $this->trxStatus = self::STATUS_TRX_NONE;
4130 $this->trxAtomicLevels = [];
4131 // Estimate the RTT via a query now that trxStatus is OK
4132 $writeTime = $this->pingAndCalculateLastTrxApplyTime();
4133
4134 if ( $this->trxDoneWrites ) {
4135 $this->trxProfiler->transactionWritingOut(
4136 $this->server,
4137 $this->getDomainID(),
4138 $oldTrxShortId,
4139 $writeTime,
4140 $this->trxWriteAffectedRows
4141 );
4142 }
4143 }
4144
4145 // Clear any commit-dependant callbacks. They might even be present
4146 // only due to transaction rounds, with no SQL transaction being active
4147 $this->trxIdleCallbacks = [];
4148 $this->trxPreCommitCallbacks = [];
4149
4150 // With FLUSHING_ALL_PEERS, callbacks will be explicitly run later
4151 if ( $trxActive && $flush !== self::FLUSHING_ALL_PEERS ) {
4152 try {
4153 $this->runOnTransactionIdleCallbacks( self::TRIGGER_ROLLBACK );
4154 } catch ( Exception $e ) {
4155 // already logged; finish and let LoadBalancer move on during mass-rollback
4156 }
4157 try {
4158 $this->runTransactionListenerCallbacks( self::TRIGGER_ROLLBACK );
4159 } catch ( Exception $e ) {
4160 // already logged; let LoadBalancer move on during mass-rollback
4161 }
4162
4163 $this->affectedRowCount = 0; // for the sake of consistency
4164 }
4165 }
4166
4167 /**
4168 * Issues the ROLLBACK command to the database server.
4169 *
4170 * @see Database::rollback()
4171 * @param string $fname
4172 * @throws DBError
4173 */
4174 protected function doRollback( $fname ) {
4175 if ( $this->trxLevel() ) {
4176 # Disconnects cause rollback anyway, so ignore those errors
4177 $ignoreErrors = true;
4178 $this->query( 'ROLLBACK', $fname, $ignoreErrors );
4179 }
4180 }
4181
4182 public function flushSnapshot( $fname = __METHOD__, $flush = self::FLUSHING_ONE ) {
4183 if ( $this->explicitTrxActive() ) {
4184 // Committing this transaction would break callers that assume it is still open
4185 throw new DBUnexpectedError(
4186 $this,
4187 "$fname: Cannot flush snapshot; " .
4188 "explicit transaction '{$this->trxFname}' is still open"
4189 );
4190 } elseif ( $this->writesOrCallbacksPending() ) {
4191 // This only flushes transactions to clear snapshots, not to write data
4192 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
4193 throw new DBUnexpectedError(
4194 $this,
4195 "$fname: Cannot flush snapshot; " .
4196 "writes from transaction {$this->trxFname} are still pending ($fnames)"
4197 );
4198 } elseif (
4199 $this->trxLevel() &&
4200 $this->getTransactionRoundId() &&
4201 $flush !== self::FLUSHING_INTERNAL &&
4202 $flush !== self::FLUSHING_ALL_PEERS
4203 ) {
4204 $this->queryLogger->warning(
4205 "$fname: Expected mass snapshot flush of all peer transactions " .
4206 "in the explicit transactions round '{$this->getTransactionRoundId()}'",
4207 [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
4208 );
4209 }
4210
4211 $this->commit( $fname, self::FLUSHING_INTERNAL );
4212 }
4213
4214 public function explicitTrxActive() {
4215 return $this->trxLevel() && ( $this->trxAtomicLevels || !$this->trxAutomatic );
4216 }
4217
4218 public function duplicateTableStructure(
4219 $oldName, $newName, $temporary = false, $fname = __METHOD__
4220 ) {
4221 throw new RuntimeException( __METHOD__ . ' is not implemented in descendant class' );
4222 }
4223
4224 public function listTables( $prefix = null, $fname = __METHOD__ ) {
4225 throw new RuntimeException( __METHOD__ . ' is not implemented in descendant class' );
4226 }
4227
4228 public function listViews( $prefix = null, $fname = __METHOD__ ) {
4229 throw new RuntimeException( __METHOD__ . ' is not implemented in descendant class' );
4230 }
4231
4232 public function timestamp( $ts = 0 ) {
4233 $t = new ConvertibleTimestamp( $ts );
4234 // Let errors bubble up to avoid putting garbage in the DB
4235 return $t->getTimestamp( TS_MW );
4236 }
4237
4238 public function timestampOrNull( $ts = null ) {
4239 if ( is_null( $ts ) ) {
4240 return null;
4241 } else {
4242 return $this->timestamp( $ts );
4243 }
4244 }
4245
4246 public function affectedRows() {
4247 return ( $this->affectedRowCount === null )
4248 ? $this->fetchAffectedRowCount() // default to driver value
4249 : $this->affectedRowCount;
4250 }
4251
4252 /**
4253 * @return int Number of retrieved rows according to the driver
4254 */
4255 abstract protected function fetchAffectedRowCount();
4256
4257 /**
4258 * Take a query result and wrap it in an iterable result wrapper if necessary.
4259 * Booleans are passed through as-is to indicate success/failure of write queries.
4260 *
4261 * Once upon a time, Database::query() returned a bare MySQL result
4262 * resource, and it was necessary to call this function to convert it to
4263 * a wrapper. Nowadays, raw database objects are never exposed to external
4264 * callers, so this is unnecessary in external code.
4265 *
4266 * @param bool|IResultWrapper|resource $result
4267 * @return bool|IResultWrapper
4268 */
4269 protected function resultObject( $result ) {
4270 if ( !$result ) {
4271 return false; // failed query
4272 } elseif ( $result instanceof IResultWrapper ) {
4273 return $result;
4274 } elseif ( $result === true ) {
4275 return $result; // succesful write query
4276 } else {
4277 return new ResultWrapper( $this, $result );
4278 }
4279 }
4280
4281 public function ping( &$rtt = null ) {
4282 // Avoid hitting the server if it was hit recently
4283 if ( $this->isOpen() && ( microtime( true ) - $this->lastPing ) < self::$PING_TTL ) {
4284 if ( !func_num_args() || $this->lastRoundTripEstimate > 0 ) {
4285 $rtt = $this->lastRoundTripEstimate;
4286 return true; // don't care about $rtt
4287 }
4288 }
4289
4290 // This will reconnect if possible or return false if not
4291 $flags = self::QUERY_IGNORE_DBO_TRX | self::QUERY_SILENCE_ERRORS;
4292 $ok = ( $this->query( self::$PING_QUERY, __METHOD__, $flags ) !== false );
4293 if ( $ok ) {
4294 $rtt = $this->lastRoundTripEstimate;
4295 }
4296
4297 return $ok;
4298 }
4299
4300 /**
4301 * Close any existing (dead) database connection and open a new connection
4302 *
4303 * @param string $fname
4304 * @return bool True if new connection is opened successfully, false if error
4305 */
4306 protected function replaceLostConnection( $fname ) {
4307 $this->closeConnection();
4308 $this->conn = null;
4309
4310 $this->handleSessionLossPreconnect();
4311
4312 try {
4313 $this->open(
4314 $this->server,
4315 $this->user,
4316 $this->password,
4317 $this->currentDomain->getDatabase(),
4318 $this->currentDomain->getSchema(),
4319 $this->tablePrefix()
4320 );
4321 $this->lastPing = microtime( true );
4322 $ok = true;
4323
4324 $this->connLogger->warning(
4325 $fname . ': lost connection to {dbserver}; reconnected',
4326 [
4327 'dbserver' => $this->getServer(),
4328 'trace' => ( new RuntimeException() )->getTraceAsString()
4329 ]
4330 );
4331 } catch ( DBConnectionError $e ) {
4332 $ok = false;
4333
4334 $this->connLogger->error(
4335 $fname . ': lost connection to {dbserver} permanently',
4336 [ 'dbserver' => $this->getServer() ]
4337 );
4338 }
4339
4340 $this->handleSessionLossPostconnect();
4341
4342 return $ok;
4343 }
4344
4345 public function getSessionLagStatus() {
4346 return $this->getRecordedTransactionLagStatus() ?: $this->getApproximateLagStatus();
4347 }
4348
4349 /**
4350 * Get the replica DB lag when the current transaction started
4351 *
4352 * This is useful when transactions might use snapshot isolation
4353 * (e.g. REPEATABLE-READ in innodb), so the "real" lag of that data
4354 * is this lag plus transaction duration. If they don't, it is still
4355 * safe to be pessimistic. This returns null if there is no transaction.
4356 *
4357 * This returns null if the lag status for this transaction was not yet recorded.
4358 *
4359 * @return array|null ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)
4360 * @since 1.27
4361 */
4362 final protected function getRecordedTransactionLagStatus() {
4363 return ( $this->trxLevel() && $this->trxReplicaLag !== null )
4364 ? [ 'lag' => $this->trxReplicaLag, 'since' => $this->trxTimestamp() ]
4365 : null;
4366 }
4367
4368 /**
4369 * Get a replica DB lag estimate for this server
4370 *
4371 * @return array ('lag': seconds or false on error, 'since': UNIX timestamp of estimate)
4372 * @since 1.27
4373 */
4374 protected function getApproximateLagStatus() {
4375 return [
4376 'lag' => $this->getLBInfo( 'replica' ) ? $this->getLag() : 0,
4377 'since' => microtime( true )
4378 ];
4379 }
4380
4381 /**
4382 * Merge the result of getSessionLagStatus() for several DBs
4383 * using the most pessimistic values to estimate the lag of
4384 * any data derived from them in combination
4385 *
4386 * This is information is useful for caching modules
4387 *
4388 * @see WANObjectCache::set()
4389 * @see WANObjectCache::getWithSetCallback()
4390 *
4391 * @param IDatabase $db1
4392 * @param IDatabase|null $db2 [optional]
4393 * @return array Map of values:
4394 * - lag: highest lag of any of the DBs or false on error (e.g. replication stopped)
4395 * - since: oldest UNIX timestamp of any of the DB lag estimates
4396 * - pending: whether any of the DBs have uncommitted changes
4397 * @throws DBError
4398 * @since 1.27
4399 */
4400 public static function getCacheSetOptions( IDatabase $db1, IDatabase $db2 = null ) {
4401 $res = [ 'lag' => 0, 'since' => INF, 'pending' => false ];
4402 foreach ( func_get_args() as $db ) {
4403 /** @var IDatabase $db */
4404 $status = $db->getSessionLagStatus();
4405 if ( $status['lag'] === false ) {
4406 $res['lag'] = false;
4407 } elseif ( $res['lag'] !== false ) {
4408 $res['lag'] = max( $res['lag'], $status['lag'] );
4409 }
4410 $res['since'] = min( $res['since'], $status['since'] );
4411 $res['pending'] = $res['pending'] ?: $db->writesPending();
4412 }
4413
4414 return $res;
4415 }
4416
4417 public function getLag() {
4418 if ( $this->getLBInfo( 'master' ) ) {
4419 return 0; // this is the master
4420 } elseif ( $this->getLBInfo( 'is static' ) ) {
4421 return 0; // static dataset
4422 }
4423
4424 return $this->doGetLag();
4425 }
4426
4427 protected function doGetLag() {
4428 return 0;
4429 }
4430
4431 public function maxListLen() {
4432 return 0;
4433 }
4434
4435 public function encodeBlob( $b ) {
4436 return $b;
4437 }
4438
4439 public function decodeBlob( $b ) {
4440 if ( $b instanceof Blob ) {
4441 $b = $b->fetch();
4442 }
4443 return $b;
4444 }
4445
4446 public function setSessionOptions( array $options ) {
4447 }
4448
4449 public function sourceFile(
4450 $filename,
4451 callable $lineCallback = null,
4452 callable $resultCallback = null,
4453 $fname = false,
4454 callable $inputCallback = null
4455 ) {
4456 AtEase::suppressWarnings();
4457 $fp = fopen( $filename, 'r' );
4458 AtEase::restoreWarnings();
4459
4460 if ( $fp === false ) {
4461 throw new RuntimeException( "Could not open \"{$filename}\"" );
4462 }
4463
4464 if ( !$fname ) {
4465 $fname = __METHOD__ . "( $filename )";
4466 }
4467
4468 try {
4469 $error = $this->sourceStream(
4470 $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
4471 } catch ( Exception $e ) {
4472 fclose( $fp );
4473 throw $e;
4474 }
4475
4476 fclose( $fp );
4477
4478 return $error;
4479 }
4480
4481 public function setSchemaVars( $vars ) {
4482 $this->schemaVars = is_array( $vars ) ? $vars : null;
4483 }
4484
4485 public function sourceStream(
4486 $fp,
4487 callable $lineCallback = null,
4488 callable $resultCallback = null,
4489 $fname = __METHOD__,
4490 callable $inputCallback = null
4491 ) {
4492 $delimiterReset = new ScopedCallback(
4493 function ( $delimiter ) {
4494 $this->delimiter = $delimiter;
4495 },
4496 [ $this->delimiter ]
4497 );
4498 $cmd = '';
4499
4500 while ( !feof( $fp ) ) {
4501 if ( $lineCallback ) {
4502 call_user_func( $lineCallback );
4503 }
4504
4505 $line = trim( fgets( $fp ) );
4506
4507 if ( $line == '' ) {
4508 continue;
4509 }
4510
4511 if ( $line[0] == '-' && $line[1] == '-' ) {
4512 continue;
4513 }
4514
4515 if ( $cmd != '' ) {
4516 $cmd .= ' ';
4517 }
4518
4519 $done = $this->streamStatementEnd( $cmd, $line );
4520
4521 $cmd .= "$line\n";
4522
4523 if ( $done || feof( $fp ) ) {
4524 $cmd = $this->replaceVars( $cmd );
4525
4526 if ( $inputCallback ) {
4527 $callbackResult = $inputCallback( $cmd );
4528
4529 if ( is_string( $callbackResult ) || !$callbackResult ) {
4530 $cmd = $callbackResult;
4531 }
4532 }
4533
4534 if ( $cmd ) {
4535 $res = $this->query( $cmd, $fname );
4536
4537 if ( $resultCallback ) {
4538 $resultCallback( $res, $this );
4539 }
4540
4541 if ( $res === false ) {
4542 $err = $this->lastError();
4543
4544 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
4545 }
4546 }
4547 $cmd = '';
4548 }
4549 }
4550
4551 ScopedCallback::consume( $delimiterReset );
4552 return true;
4553 }
4554
4555 /**
4556 * Called by sourceStream() to check if we've reached a statement end
4557 *
4558 * @param string &$sql SQL assembled so far
4559 * @param string &$newLine New line about to be added to $sql
4560 * @return bool Whether $newLine contains end of the statement
4561 */
4562 public function streamStatementEnd( &$sql, &$newLine ) {
4563 if ( $this->delimiter ) {
4564 $prev = $newLine;
4565 $newLine = preg_replace(
4566 '/' . preg_quote( $this->delimiter, '/' ) . '$/', '', $newLine );
4567 if ( $newLine != $prev ) {
4568 return true;
4569 }
4570 }
4571
4572 return false;
4573 }
4574
4575 /**
4576 * Database independent variable replacement. Replaces a set of variables
4577 * in an SQL statement with their contents as given by $this->getSchemaVars().
4578 *
4579 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
4580 *
4581 * - '{$var}' should be used for text and is passed through the database's
4582 * addQuotes method.
4583 * - `{$var}` should be used for identifiers (e.g. table and database names).
4584 * It is passed through the database's addIdentifierQuotes method which
4585 * can be overridden if the database uses something other than backticks.
4586 * - / *_* / or / *$wgDBprefix* / passes the name that follows through the
4587 * database's tableName method.
4588 * - / *i* / passes the name that follows through the database's indexName method.
4589 * - In all other cases, / *$var* / is left unencoded. Except for table options,
4590 * its use should be avoided. In 1.24 and older, string encoding was applied.
4591 *
4592 * @param string $ins SQL statement to replace variables in
4593 * @return string The new SQL statement with variables replaced
4594 */
4595 protected function replaceVars( $ins ) {
4596 $vars = $this->getSchemaVars();
4597 return preg_replace_callback(
4598 '!
4599 /\* (\$wgDBprefix|[_i]) \*/ (\w*) | # 1-2. tableName, indexName
4600 \'\{\$ (\w+) }\' | # 3. addQuotes
4601 `\{\$ (\w+) }` | # 4. addIdentifierQuotes
4602 /\*\$ (\w+) \*/ # 5. leave unencoded
4603 !x',
4604 function ( $m ) use ( $vars ) {
4605 // Note: Because of <https://bugs.php.net/bug.php?id=51881>,
4606 // check for both nonexistent keys *and* the empty string.
4607 if ( isset( $m[1] ) && $m[1] !== '' ) {
4608 if ( $m[1] === 'i' ) {
4609 return $this->indexName( $m[2] );
4610 } else {
4611 return $this->tableName( $m[2] );
4612 }
4613 } elseif ( isset( $m[3] ) && $m[3] !== '' && array_key_exists( $m[3], $vars ) ) {
4614 return $this->addQuotes( $vars[$m[3]] );
4615 } elseif ( isset( $m[4] ) && $m[4] !== '' && array_key_exists( $m[4], $vars ) ) {
4616 return $this->addIdentifierQuotes( $vars[$m[4]] );
4617 } elseif ( isset( $m[5] ) && $m[5] !== '' && array_key_exists( $m[5], $vars ) ) {
4618 return $vars[$m[5]];
4619 } else {
4620 return $m[0];
4621 }
4622 },
4623 $ins
4624 );
4625 }
4626
4627 /**
4628 * Get schema variables. If none have been set via setSchemaVars(), then
4629 * use some defaults from the current object.
4630 *
4631 * @return array
4632 */
4633 protected function getSchemaVars() {
4634 return $this->schemaVars ?? $this->getDefaultSchemaVars();
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 * @since 1.34
4825 */
4826 final protected function fieldHasBit( $field, $flags ) {
4827 return ( ( $field & $flags ) === $flags );
4828 }
4829
4830 /**
4831 * Get the underlying binding connection handle
4832 *
4833 * Makes sure the connection resource is set (disconnects and ping() failure can unset it).
4834 * This catches broken callers than catch and ignore disconnection exceptions.
4835 * Unlike checking isOpen(), this is safe to call inside of open().
4836 *
4837 * @return mixed
4838 * @throws DBUnexpectedError
4839 * @since 1.26
4840 */
4841 protected function getBindingHandle() {
4842 if ( !$this->conn ) {
4843 throw new DBUnexpectedError(
4844 $this,
4845 'DB connection was already closed or the connection dropped'
4846 );
4847 }
4848
4849 return $this->conn;
4850 }
4851
4852 public function __toString() {
4853 // spl_object_id is PHP >= 7.2
4854 $id = function_exists( 'spl_object_id' )
4855 ? spl_object_id( $this )
4856 : spl_object_hash( $this );
4857
4858 $description = $this->getType() . ' object #' . $id;
4859 if ( is_resource( $this->conn ) ) {
4860 $description .= ' (' . (string)$this->conn . ')'; // "resource id #<ID>"
4861 } elseif ( is_object( $this->conn ) ) {
4862 // spl_object_id is PHP >= 7.2
4863 $handleId = function_exists( 'spl_object_id' )
4864 ? spl_object_id( $this->conn )
4865 : spl_object_hash( $this->conn );
4866 $description .= " (handle id #$handleId)";
4867 }
4868
4869 return $description;
4870 }
4871
4872 /**
4873 * Make sure that copies do not share the same client binding handle
4874 * @throws DBConnectionError
4875 */
4876 public function __clone() {
4877 $this->connLogger->warning(
4878 "Cloning " . static::class . " is not recommended; forking connection",
4879 [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
4880 );
4881
4882 if ( $this->isOpen() ) {
4883 // Open a new connection resource without messing with the old one
4884 $this->conn = null;
4885 $this->trxEndCallbacks = []; // don't copy
4886 $this->trxSectionCancelCallbacks = []; // don't copy
4887 $this->handleSessionLossPreconnect(); // no trx or locks anymore
4888 $this->open(
4889 $this->server,
4890 $this->user,
4891 $this->password,
4892 $this->currentDomain->getDatabase(),
4893 $this->currentDomain->getSchema(),
4894 $this->tablePrefix()
4895 );
4896 $this->lastPing = microtime( true );
4897 }
4898 }
4899
4900 /**
4901 * Called by serialize. Throw an exception when DB connection is serialized.
4902 * This causes problems on some database engines because the connection is
4903 * not restored on unserialize.
4904 */
4905 public function __sleep() {
4906 throw new RuntimeException( 'Database serialization may cause problems, since ' .
4907 'the connection is not restored on wakeup' );
4908 }
4909
4910 /**
4911 * Run a few simple sanity checks and close dangling connections
4912 */
4913 public function __destruct() {
4914 if ( $this->trxLevel() && $this->trxDoneWrites ) {
4915 trigger_error( "Uncommitted DB writes (transaction from {$this->trxFname})" );
4916 }
4917
4918 $danglingWriters = $this->pendingWriteAndCallbackCallers();
4919 if ( $danglingWriters ) {
4920 $fnames = implode( ', ', $danglingWriters );
4921 trigger_error( "DB transaction writes or callbacks still pending ($fnames)" );
4922 }
4923
4924 if ( $this->conn ) {
4925 // Avoid connection leaks for sanity. Normally, resources close at script completion.
4926 // The connection might already be closed in zend/hhvm by now, so suppress warnings.
4927 AtEase::suppressWarnings();
4928 $this->closeConnection();
4929 AtEase::restoreWarnings();
4930 $this->conn = null;
4931 }
4932 }
4933 }
4934
4935 /**
4936 * @deprecated since 1.28
4937 */
4938 class_alias( Database::class, 'DatabaseBase' );
4939
4940 /**
4941 * @deprecated since 1.29
4942 */
4943 class_alias( Database::class, 'Database' );
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