includes/libs/rdbms/database/DatabaseMysqlBase.php

   1 <?php
   2 /**
   3  * This is the MySQL database abstraction layer.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Database
  22  */
  23 namespace Wikimedia\Rdbms;
  24
  25 use DateTime;
  26 use DateTimeZone;
  27 use Wikimedia\AtEase\AtEase;
  28 use InvalidArgumentException;
  29 use Exception;
  30 use RuntimeException;
  31 use stdClass;
  32
  33 /**
  34  * Database abstraction object for MySQL.
  35  * Defines methods independent on used MySQL extension.
  36  *
  37  * @ingroup Database
  38  * @since 1.22
  39  * @see Database
  40  */
  41 abstract class DatabaseMysqlBase extends Database {
  42         /** @var MysqlMasterPos */
  43         protected $lastKnownReplicaPos;
  44         /** @var string Method to detect replica DB lag */
  45         protected $lagDetectionMethod;
  46         /** @var array Method to detect replica DB lag */
  47         protected $lagDetectionOptions = [];
  48         /** @var bool bool Whether to use GTID methods */
  49         protected $useGTIDs = false;
  50         /** @var string|null */
  51         protected $sslKeyPath;
  52         /** @var string|null */
  53         protected $sslCertPath;
  54         /** @var string|null */
  55         protected $sslCAFile;
  56         /** @var string|null */
  57         protected $sslCAPath;
  58         /** @var string[]|null */
  59         protected $sslCiphers;
  60         /** @var string sql_mode value to send on connection */
  61         protected $sqlMode;
  62         /** @var bool Use experimental UTF-8 transmission encoding */
  63         protected $utf8Mode;
  64         /** @var bool|null */
  65         protected $defaultBigSelects = null;
  66
  67         /** @var string|null */
  68         private $serverVersion = null;
  69         /** @var bool|null */
  70         private $insertSelectIsSafe = null;
  71         /** @var stdClass|null */
  72         private $replicationInfoRow = null;
  73
  74         // Cache getServerId() for 24 hours
  75         const SERVER_ID_CACHE_TTL = 86400;
  76
  77         /** @var float Warn if lag estimates are made for transactions older than this many seconds */
  78         const LAG_STALE_WARN_THRESHOLD = 0.100;
  79
  80         /**
  81          * Additional $params include:
  82          *   - lagDetectionMethod : set to one of (Seconds_Behind_Master,pt-heartbeat).
  83          *       pt-heartbeat assumes the table is at heartbeat.heartbeat
  84          *       and uses UTC timestamps in the heartbeat.ts column.
  85          *       (https://www.percona.com/doc/percona-toolkit/2.2/pt-heartbeat.html)
  86          *   - lagDetectionOptions : if using pt-heartbeat, this can be set to an array map to change
  87          *       the default behavior. Normally, the heartbeat row with the server
  88          *       ID of this server's master will be used. Set the "conds" field to
  89          *       override the query conditions, e.g. ['shard' => 's1'].
  90          *   - useGTIDs : use GTID methods like MASTER_GTID_WAIT() when possible.
  91          *   - insertSelectIsSafe : force that native INSERT SELECT is or is not safe [default: null]
  92          *   - sslKeyPath : path to key file [default: null]
  93          *   - sslCertPath : path to certificate file [default: null]
  94          *   - sslCAFile: path to a single certificate authority PEM file [default: null]
  95          *   - sslCAPath : parth to certificate authority PEM directory [default: null]
  96          *   - sslCiphers : array list of allowable ciphers [default: null]
  97          * @param array $params
  98          */
  99         public function __construct( array $params ) {
 100                 $this->lagDetectionMethod = $params['lagDetectionMethod'] ?? 'Seconds_Behind_Master';
 101                 $this->lagDetectionOptions = $params['lagDetectionOptions'] ?? [];
 102                 $this->useGTIDs = !empty( $params['useGTIDs' ] );
 103                 foreach ( [ 'KeyPath', 'CertPath', 'CAFile', 'CAPath', 'Ciphers' ] as $name ) {
 104                         $var = "ssl{$name}";
 105                         if ( isset( $params[$var] ) ) {
 106                                 $this->$var = $params[$var];
 107                         }
 108                 }
 109                 $this->sqlMode = $params['sqlMode'] ?? null;
 110                 $this->utf8Mode = !empty( $params['utf8Mode'] );
 111                 $this->insertSelectIsSafe = isset( $params['insertSelectIsSafe'] )
 112                         ? (bool)$params['insertSelectIsSafe'] : null;
 113
 114                 parent::__construct( $params );
 115         }
 116
 117         /**
 118          * @return string
 119          */
 120         public function getType() {
 121                 return 'mysql';
 122         }
 123
 124         protected function open( $server, $user, $password, $dbName, $schema, $tablePrefix ) {
 125                 $this->close();
 126
 127                 if ( $schema !== null ) {
 128                         throw new DBExpectedError( $this, __CLASS__ . ": cannot use schemas ('$schema')" );
 129                 }
 130
 131                 $this->server = $server;
 132                 $this->user = $user;
 133                 $this->password = $password;
 134
 135                 $this->installErrorHandler();
 136                 try {
 137                         $this->conn = $this->mysqlConnect( $this->server, $dbName );
 138                 } catch ( Exception $ex ) {
 139                         $this->restoreErrorHandler();
 140                         throw $ex;
 141                 }
 142                 $error = $this->restoreErrorHandler();
 143
 144                 # Always log connection errors
 145                 if ( !$this->conn ) {
 146                         $error = $error ?: $this->lastError();
 147                         $this->connLogger->error(
 148                                 "Error connecting to {db_server}: {error}",
 149                                 $this->getLogContext( [ 'method' => __METHOD__, 'error' => $error ] )
 150                         );
 151                         $this->connLogger->debug( "DB connection error\n" .
 152                                 "Server: $server, User: $user, Password: " .
 153                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 154                         throw new DBConnectionError( $this, $error );
 155                 }
 156
 157                 try {
 158                         $this->currentDomain = new DatabaseDomain(
 159                                 strlen( $dbName ) ? $dbName : null,
 160                                 null,
 161                                 $tablePrefix
 162                         );
 163
 164                         // Abstract over any insane MySQL defaults
 165                         $set = [ 'group_concat_max_len = 262144' ];
 166                         // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 167                         if ( is_string( $this->sqlMode ) ) {
 168                                 $set[] = 'sql_mode = ' . $this->addQuotes( $this->sqlMode );
 169                         }
 170                         // Set any custom settings defined by site config
 171                         // (e.g. https://dev.mysql.com/doc/refman/4.1/en/innodb-parameters.html)
 172                         foreach ( $this->connectionVariables as $var => $val ) {
 173                                 // Escape strings but not numbers to avoid MySQL complaining
 174                                 if ( !is_int( $val ) && !is_float( $val ) ) {
 175                                         $val = $this->addQuotes( $val );
 176                                 }
 177                                 $set[] = $this->addIdentifierQuotes( $var ) . ' = ' . $val;
 178                         }
 179
 180                         if ( $set ) {
 181                                 $this->query(
 182                                         'SET ' . implode( ', ', $set ),
 183                                         __METHOD__,
 184                                         self::QUERY_IGNORE_DBO_TRX | self::QUERY_NO_RETRY
 185                                 );
 186                         }
 187                 } catch ( Exception $e ) {
 188                         // Connection was not fully initialized and is not safe for use
 189                         $this->conn = false;
 190                 }
 191
 192                 return true;
 193         }
 194
 195         protected function doSelectDomain( DatabaseDomain $domain ) {
 196                 if ( $domain->getSchema() !== null ) {
 197                         throw new DBExpectedError(
 198                                 $this,
 199                                 __CLASS__ . ": domain '{$domain->getId()}' has a schema component"
 200                         );
 201                 }
 202
 203                 $database = $domain->getDatabase();
 204                 // A null database means "don't care" so leave it as is and update the table prefix
 205                 if ( $database === null ) {
 206                         $this->currentDomain = new DatabaseDomain(
 207                                 $this->currentDomain->getDatabase(),
 208                                 null,
 209                                 $domain->getTablePrefix()
 210                         );
 211
 212                         return true;
 213                 }
 214
 215                 if ( $database !== $this->getDBname() ) {
 216                         $sql = 'USE ' . $this->addIdentifierQuotes( $database );
 217                         list( $res, $err, $errno ) =
 218                                 $this->executeQuery( $sql, __METHOD__, self::QUERY_IGNORE_DBO_TRX );
 219
 220                         if ( $res === false ) {
 221                                 $this->reportQueryError( $err, $errno, $sql, __METHOD__ );
 222                                 return false; // unreachable
 223                         }
 224                 }
 225
 226                 // Update that domain fields on success (no exception thrown)
 227                 $this->currentDomain = $domain;
 228
 229                 return true;
 230         }
 231
 232         /**
 233          * Open a connection to a MySQL server
 234          *
 235          * @param string $realServer
 236          * @param string|null $dbName
 237          * @return mixed Raw connection
 238          * @throws DBConnectionError
 239          */
 240         abstract protected function mysqlConnect( $realServer, $dbName );
 241
 242         /**
 243          * @param IResultWrapper|resource $res
 244          * @throws DBUnexpectedError
 245          */
 246         public function freeResult( $res ) {
 247                 AtEase::suppressWarnings();
 248                 $ok = $this->mysqlFreeResult( ResultWrapper::unwrap( $res ) );
 249                 AtEase::restoreWarnings();
 250                 if ( !$ok ) {
 251                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 252                 }
 253         }
 254
 255         /**
 256          * Free result memory
 257          *
 258          * @param resource $res Raw result
 259          * @return bool
 260          */
 261         abstract protected function mysqlFreeResult( $res );
 262
 263         /**
 264          * @param IResultWrapper|resource $res
 265          * @return stdClass|bool
 266          * @throws DBUnexpectedError
 267          */
 268         public function fetchObject( $res ) {
 269                 AtEase::suppressWarnings();
 270                 $row = $this->mysqlFetchObject( ResultWrapper::unwrap( $res ) );
 271                 AtEase::restoreWarnings();
 272
 273                 $errno = $this->lastErrno();
 274                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 275                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 276                 // these are the only errors mysql_fetch_object can cause.
 277                 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 278                 if ( $errno == 2000 || $errno == 2013 ) {
 279                         throw new DBUnexpectedError(
 280                                 $this,
 281                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 282                         );
 283                 }
 284
 285                 return $row;
 286         }
 287
 288         /**
 289          * Fetch a result row as an object
 290          *
 291          * @param resource $res Raw result
 292          * @return stdClass
 293          */
 294         abstract protected function mysqlFetchObject( $res );
 295
 296         /**
 297          * @param IResultWrapper|resource $res
 298          * @return array|bool
 299          * @throws DBUnexpectedError
 300          */
 301         public function fetchRow( $res ) {
 302                 AtEase::suppressWarnings();
 303                 $row = $this->mysqlFetchArray( ResultWrapper::unwrap( $res ) );
 304                 AtEase::restoreWarnings();
 305
 306                 $errno = $this->lastErrno();
 307                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 308                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 309                 // these are the only errors mysql_fetch_array can cause.
 310                 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 311                 if ( $errno == 2000 || $errno == 2013 ) {
 312                         throw new DBUnexpectedError(
 313                                 $this,
 314                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 315                         );
 316                 }
 317
 318                 return $row;
 319         }
 320
 321         /**
 322          * Fetch a result row as an associative and numeric array
 323          *
 324          * @param resource $res Raw result
 325          * @return array|false
 326          */
 327         abstract protected function mysqlFetchArray( $res );
 328
 329         /**
 330          * @throws DBUnexpectedError
 331          * @param IResultWrapper|resource $res
 332          * @return int
 333          */
 334         function numRows( $res ) {
 335                 if ( is_bool( $res ) ) {
 336                         $n = 0;
 337                 } else {
 338                         AtEase::suppressWarnings();
 339                         $n = $this->mysqlNumRows( ResultWrapper::unwrap( $res ) );
 340                         AtEase::restoreWarnings();
 341                 }
 342
 343                 // Unfortunately, mysql_num_rows does not reset the last errno.
 344                 // We are not checking for any errors here, since
 345                 // there are no errors mysql_num_rows can cause.
 346                 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 347                 // See https://phabricator.wikimedia.org/T44430
 348                 return $n;
 349         }
 350
 351         /**
 352          * Get number of rows in result
 353          *
 354          * @param resource $res Raw result
 355          * @return int
 356          */
 357         abstract protected function mysqlNumRows( $res );
 358
 359         /**
 360          * @param IResultWrapper|resource $res
 361          * @return int
 362          */
 363         public function numFields( $res ) {
 364                 return $this->mysqlNumFields( ResultWrapper::unwrap( $res ) );
 365         }
 366
 367         /**
 368          * Get number of fields in result
 369          *
 370          * @param resource $res Raw result
 371          * @return int
 372          */
 373         abstract protected function mysqlNumFields( $res );
 374
 375         /**
 376          * @param IResultWrapper|resource $res
 377          * @param int $n
 378          * @return string
 379          */
 380         public function fieldName( $res, $n ) {
 381                 return $this->mysqlFieldName( ResultWrapper::unwrap( $res ), $n );
 382         }
 383
 384         /**
 385          * Get the name of the specified field in a result
 386          *
 387          * @param IResultWrapper|resource $res
 388          * @param int $n
 389          * @return string
 390          */
 391         abstract protected function mysqlFieldName( $res, $n );
 392
 393         /**
 394          * mysql_field_type() wrapper
 395          * @param IResultWrapper|resource $res
 396          * @param int $n
 397          * @return string
 398          */
 399         public function fieldType( $res, $n ) {
 400                 return $this->mysqlFieldType( ResultWrapper::unwrap( $res ), $n );
 401         }
 402
 403         /**
 404          * Get the type of the specified field in a result
 405          *
 406          * @param IResultWrapper|resource $res
 407          * @param int $n
 408          * @return string
 409          */
 410         abstract protected function mysqlFieldType( $res, $n );
 411
 412         /**
 413          * @param IResultWrapper|resource $res
 414          * @param int $row
 415          * @return bool
 416          */
 417         public function dataSeek( $res, $row ) {
 418                 return $this->mysqlDataSeek( ResultWrapper::unwrap( $res ), $row );
 419         }
 420
 421         /**
 422          * Move internal result pointer
 423          *
 424          * @param IResultWrapper|resource $res
 425          * @param int $row
 426          * @return bool
 427          */
 428         abstract protected function mysqlDataSeek( $res, $row );
 429
 430         /**
 431          * @return string
 432          */
 433         public function lastError() {
 434                 if ( $this->conn ) {
 435                         # Even if it's non-zero, it can still be invalid
 436                         AtEase::suppressWarnings();
 437                         $error = $this->mysqlError( $this->conn );
 438                         if ( !$error ) {
 439                                 $error = $this->mysqlError();
 440                         }
 441                         AtEase::restoreWarnings();
 442                 } else {
 443                         $error = $this->mysqlError();
 444                 }
 445                 if ( $error ) {
 446                         $error .= ' (' . $this->server . ')';
 447                 }
 448
 449                 return $error;
 450         }
 451
 452         /**
 453          * Returns the text of the error message from previous MySQL operation
 454          *
 455          * @param resource|null $conn Raw connection
 456          * @return string
 457          */
 458         abstract protected function mysqlError( $conn = null );
 459
 460         protected function wasQueryTimeout( $error, $errno ) {
 461                 // https://dev.mysql.com/doc/refman/8.0/en/client-error-reference.html
 462                 // https://phabricator.wikimedia.org/T170638
 463                 return in_array( $errno, [ 2062, 3024 ] );
 464         }
 465
 466         public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 467                 $this->nativeReplace( $table, $rows, $fname );
 468         }
 469
 470         protected function isInsertSelectSafe( array $insertOptions, array $selectOptions ) {
 471                 $row = $this->getReplicationSafetyInfo();
 472                 // For row-based-replication, the resulting changes will be relayed, not the query
 473                 if ( $row->binlog_format === 'ROW' ) {
 474                         return true;
 475                 }
 476                 // LIMIT requires ORDER BY on a unique key or it is non-deterministic
 477                 if ( isset( $selectOptions['LIMIT'] ) ) {
 478                         return false;
 479                 }
 480                 // In MySQL, an INSERT SELECT is only replication safe with row-based
 481                 // replication or if innodb_autoinc_lock_mode is 0. When those
 482                 // conditions aren't met, use non-native mode.
 483                 // While we could try to determine if the insert is safe anyway by
 484                 // checking if the target table has an auto-increment column that
 485                 // isn't set in $varMap, that seems unlikely to be worth the extra
 486                 // complexity.
 487                 return (
 488                         in_array( 'NO_AUTO_COLUMNS', $insertOptions ) ||
 489                         (int)$row->innodb_autoinc_lock_mode === 0
 490                 );
 491         }
 492
 493         /**
 494          * @return stdClass Process cached row
 495          */
 496         protected function getReplicationSafetyInfo() {
 497                 if ( $this->replicationInfoRow === null ) {
 498                         $this->replicationInfoRow = $this->selectRow(
 499                                 false,
 500                                 [
 501                                         'innodb_autoinc_lock_mode' => '@@innodb_autoinc_lock_mode',
 502                                         'binlog_format' => '@@binlog_format',
 503                                 ],
 504                                 [],
 505                                 __METHOD__
 506                         );
 507                 }
 508
 509                 return $this->replicationInfoRow;
 510         }
 511
 512         /**
 513          * Estimate rows in dataset
 514          * Returns estimated count, based on EXPLAIN output
 515          * Takes same arguments as Database::select()
 516          *
 517          * @param string|array $table
 518          * @param string|array $var
 519          * @param string|array $conds
 520          * @param string $fname
 521          * @param string|array $options
 522          * @param array $join_conds
 523          * @return bool|int
 524          */
 525         public function estimateRowCount( $table, $var = '*', $conds = '',
 526                 $fname = __METHOD__, $options = [], $join_conds = []
 527         ) {
 528                 $conds = $this->normalizeConditions( $conds, $fname );
 529                 $column = $this->extractSingleFieldFromList( $var );
 530                 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
 531                         $conds[] = "$column IS NOT NULL";
 532                 }
 533
 534                 $options['EXPLAIN'] = true;
 535                 $res = $this->select( $table, $var, $conds, $fname, $options, $join_conds );
 536                 if ( $res === false ) {
 537                         return false;
 538                 }
 539                 if ( !$this->numRows( $res ) ) {
 540                         return 0;
 541                 }
 542
 543                 $rows = 1;
 544                 foreach ( $res as $plan ) {
 545                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 546                 }
 547
 548                 return (int)$rows;
 549         }
 550
 551         public function tableExists( $table, $fname = __METHOD__ ) {
 552                 // Split database and table into proper variables as Database::tableName() returns
 553                 // shared tables prefixed with their database, which do not work in SHOW TABLES statements
 554                 list( $database, , $prefix, $table ) = $this->qualifiedTableComponents( $table );
 555                 $tableName = "{$prefix}{$table}";
 556
 557                 if ( isset( $this->sessionTempTables[$tableName] ) ) {
 558                         return true; // already known to exist and won't show in SHOW TABLES anyway
 559                 }
 560
 561                 // We can't use buildLike() here, because it specifies an escape character
 562                 // other than the backslash, which is the only one supported by SHOW TABLES
 563                 $encLike = $this->escapeLikeInternal( $tableName, '\\' );
 564
 565                 // If the database has been specified (such as for shared tables), use "FROM"
 566                 if ( $database !== '' ) {
 567                         $encDatabase = $this->addIdentifierQuotes( $database );
 568                         $query = "SHOW TABLES FROM $encDatabase LIKE '$encLike'";
 569                 } else {
 570                         $query = "SHOW TABLES LIKE '$encLike'";
 571                 }
 572
 573                 return $this->query( $query, $fname )->numRows() > 0;
 574         }
 575
 576         /**
 577          * @param string $table
 578          * @param string $field
 579          * @return bool|MySQLField
 580          */
 581         public function fieldInfo( $table, $field ) {
 582                 $table = $this->tableName( $table );
 583                 $flags = self::QUERY_SILENCE_ERRORS;
 584                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, $flags );
 585                 if ( !$res ) {
 586                         return false;
 587                 }
 588                 $n = $this->mysqlNumFields( ResultWrapper::unwrap( $res ) );
 589                 for ( $i = 0; $i < $n; $i++ ) {
 590                         $meta = $this->mysqlFetchField( ResultWrapper::unwrap( $res ), $i );
 591                         if ( $field == $meta->name ) {
 592                                 return new MySQLField( $meta );
 593                         }
 594                 }
 595
 596                 return false;
 597         }
 598
 599         /**
 600          * Get column information from a result
 601          *
 602          * @param resource $res Raw result
 603          * @param int $n
 604          * @return stdClass
 605          */
 606         abstract protected function mysqlFetchField( $res, $n );
 607
 608         /**
 609          * Get information about an index into an object
 610          * Returns false if the index does not exist
 611          *
 612          * @param string $table
 613          * @param string $index
 614          * @param string $fname
 615          * @return bool|array|null False or null on failure
 616          */
 617         public function indexInfo( $table, $index, $fname = __METHOD__ ) {
 618                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 619                 # SHOW INDEX should work for 3.x and up:
 620                 # https://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 621                 $table = $this->tableName( $table );
 622                 $index = $this->indexName( $index );
 623
 624                 $sql = 'SHOW INDEX FROM ' . $table;
 625                 $res = $this->query( $sql, $fname );
 626
 627                 if ( !$res ) {
 628                         return null;
 629                 }
 630
 631                 $result = [];
 632
 633                 foreach ( $res as $row ) {
 634                         if ( $row->Key_name == $index ) {
 635                                 $result[] = $row;
 636                         }
 637                 }
 638
 639                 return $result ?: false;
 640         }
 641
 642         /**
 643          * @param string $s
 644          * @return string
 645          */
 646         public function strencode( $s ) {
 647                 return $this->mysqlRealEscapeString( $s );
 648         }
 649
 650         /**
 651          * @param string $s
 652          * @return mixed
 653          */
 654         abstract protected function mysqlRealEscapeString( $s );
 655
 656         public function addQuotes( $s ) {
 657                 if ( is_bool( $s ) ) {
 658                         // Parent would transform to int, which does not play nice with MySQL type juggling.
 659                         // When searching for an int in a string column, the strings are cast to int, which
 660                         // means false would match any string not starting with a number.
 661                         $s = (string)(int)$s;
 662                 }
 663                 return parent::addQuotes( $s );
 664         }
 665
 666         /**
 667          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 668          *
 669          * @param string $s
 670          * @return string
 671          */
 672         public function addIdentifierQuotes( $s ) {
 673                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 674                 // Remove NUL bytes and escape backticks by doubling
 675                 return '`' . str_replace( [ "\0", '`' ], [ '', '``' ], $s ) . '`';
 676         }
 677
 678         /**
 679          * @param string $name
 680          * @return bool
 681          */
 682         public function isQuotedIdentifier( $name ) {
 683                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 684         }
 685
 686         protected function doGetLag() {
 687                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 688                         return $this->getLagFromPtHeartbeat();
 689                 } else {
 690                         return $this->getLagFromSlaveStatus();
 691                 }
 692         }
 693
 694         /**
 695          * @return string
 696          */
 697         protected function getLagDetectionMethod() {
 698                 return $this->lagDetectionMethod;
 699         }
 700
 701         /**
 702          * @return bool|int
 703          */
 704         protected function getLagFromSlaveStatus() {
 705                 $flags = self::QUERY_SILENCE_ERRORS | self::QUERY_IGNORE_DBO_TRX;
 706                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__, $flags );
 707                 $row = $res ? $res->fetchObject() : false;
 708                 // If the server is not replicating, there will be no row
 709                 if ( $row && strval( $row->Seconds_Behind_Master ) !== '' ) {
 710                         return intval( $row->Seconds_Behind_Master );
 711                 }
 712
 713                 return false;
 714         }
 715
 716         /**
 717          * @return bool|float
 718          */
 719         protected function getLagFromPtHeartbeat() {
 720                 $options = $this->lagDetectionOptions;
 721
 722                 $currentTrxInfo = $this->getRecordedTransactionLagStatus();
 723                 if ( $currentTrxInfo ) {
 724                         // There is an active transaction and the initial lag was already queried
 725                         $staleness = microtime( true ) - $currentTrxInfo['since'];
 726                         if ( $staleness > self::LAG_STALE_WARN_THRESHOLD ) {
 727                                 // Avoid returning higher and higher lag value due to snapshot age
 728                                 // given that the isolation level will typically be REPEATABLE-READ
 729                                 $this->queryLogger->warning(
 730                                         "Using cached lag value for {db_server} due to active transaction",
 731                                         $this->getLogContext( [
 732                                                 'method' => __METHOD__,
 733                                                 'age' => $staleness,
 734                                                 'trace' => ( new RuntimeException() )->getTraceAsString()
 735                                         ] )
 736                                 );
 737                         }
 738
 739                         return $currentTrxInfo['lag'];
 740                 }
 741
 742                 if ( isset( $options['conds'] ) ) {
 743                         // Best method for multi-DC setups: use logical channel names
 744                         $data = $this->getHeartbeatData( $options['conds'] );
 745                 } else {
 746                         // Standard method: use master server ID (works with stock pt-heartbeat)
 747                         $masterInfo = $this->getMasterServerInfo();
 748                         if ( !$masterInfo ) {
 749                                 $this->queryLogger->error(
 750                                         "Unable to query master of {db_server} for server ID",
 751                                         $this->getLogContext( [
 752                                                 'method' => __METHOD__
 753                                         ] )
 754                                 );
 755
 756                                 return false; // could not get master server ID
 757                         }
 758
 759                         $conds = [ 'server_id' => intval( $masterInfo['serverId'] ) ];
 760                         $data = $this->getHeartbeatData( $conds );
 761                 }
 762
 763                 list( $time, $nowUnix ) = $data;
 764                 if ( $time !== null ) {
 765                         // @time is in ISO format like "2015-09-25T16:48:10.000510"
 766                         $dateTime = new DateTime( $time, new DateTimeZone( 'UTC' ) );
 767                         $timeUnix = (int)$dateTime->format( 'U' ) + $dateTime->format( 'u' ) / 1e6;
 768
 769                         return max( $nowUnix - $timeUnix, 0.0 );
 770                 }
 771
 772                 $this->queryLogger->error(
 773                         "Unable to find pt-heartbeat row for {db_server}",
 774                         $this->getLogContext( [
 775                                 'method' => __METHOD__
 776                         ] )
 777                 );
 778
 779                 return false;
 780         }
 781
 782         protected function getMasterServerInfo() {
 783                 $cache = $this->srvCache;
 784                 $key = $cache->makeGlobalKey(
 785                         'mysql',
 786                         'master-info',
 787                         // Using one key for all cluster replica DBs is preferable
 788                         $this->getLBInfo( 'clusterMasterHost' ) ?: $this->getServer()
 789                 );
 790                 $fname = __METHOD__;
 791
 792                 return $cache->getWithSetCallback(
 793                         $key,
 794                         $cache::TTL_INDEFINITE,
 795                         function () use ( $cache, $key, $fname ) {
 796                                 // Get and leave a lock key in place for a short period
 797                                 if ( !$cache->lock( $key, 0, 10 ) ) {
 798                                         return false; // avoid master connection spike slams
 799                                 }
 800
 801                                 $conn = $this->getLazyMasterHandle();
 802                                 if ( !$conn ) {
 803                                         return false; // something is misconfigured
 804                                 }
 805
 806                                 // Connect to and query the master; catch errors to avoid outages
 807                                 try {
 808                                         $flags = self::QUERY_SILENCE_ERRORS | self::QUERY_IGNORE_DBO_TRX;
 809                                         $res = $conn->query( 'SELECT @@server_id AS id', $fname, $flags );
 810                                         $row = $res ? $res->fetchObject() : false;
 811                                         $id = $row ? (int)$row->id : 0;
 812                                 } catch ( DBError $e ) {
 813                                         $id = 0;
 814                                 }
 815
 816                                 // Cache the ID if it was retrieved
 817                                 return $id ? [ 'serverId' => $id, 'asOf' => time() ] : false;
 818                         }
 819                 );
 820         }
 821
 822         /**
 823          * @param array $conds WHERE clause conditions to find a row
 824          * @return array (heartbeat `ts` column value or null, UNIX timestamp) for the newest beat
 825          * @see https://www.percona.com/doc/percona-toolkit/2.1/pt-heartbeat.html
 826          */
 827         protected function getHeartbeatData( array $conds ) {
 828                 // Query time and trip time are not counted
 829                 $nowUnix = microtime( true );
 830                 // Do not bother starting implicit transactions here
 831                 $this->clearFlag( self::DBO_TRX, self::REMEMBER_PRIOR );
 832                 try {
 833                         $whereSQL = $this->makeList( $conds, self::LIST_AND );
 834                         // Use ORDER BY for channel based queries since that field might not be UNIQUE.
 835                         // Note: this would use "TIMESTAMPDIFF(MICROSECOND,ts,UTC_TIMESTAMP(6))" but the
 836                         // percision field is not supported in MySQL <= 5.5.
 837                         $res = $this->query(
 838                                 "SELECT ts FROM heartbeat.heartbeat WHERE $whereSQL ORDER BY ts DESC LIMIT 1",
 839                                 __METHOD__,
 840                                 self::QUERY_SILENCE_ERRORS | self::QUERY_IGNORE_DBO_TRX
 841                         );
 842                         $row = $res ? $res->fetchObject() : false;
 843                 } finally {
 844                         $this->restoreFlags();
 845                 }
 846
 847                 return [ $row ? $row->ts : null, $nowUnix ];
 848         }
 849
 850         protected function getApproximateLagStatus() {
 851                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 852                         // Disable caching since this is fast enough and we don't wan't
 853                         // to be *too* pessimistic by having both the cache TTL and the
 854                         // pt-heartbeat interval count as lag in getSessionLagStatus()
 855                         return parent::getApproximateLagStatus();
 856                 }
 857
 858                 $key = $this->srvCache->makeGlobalKey( 'mysql-lag', $this->getServer() );
 859                 $approxLag = $this->srvCache->get( $key );
 860                 if ( !$approxLag ) {
 861                         $approxLag = parent::getApproximateLagStatus();
 862                         $this->srvCache->set( $key, $approxLag, 1 );
 863                 }
 864
 865                 return $approxLag;
 866         }
 867
 868         public function masterPosWait( DBMasterPos $pos, $timeout ) {
 869                 if ( !( $pos instanceof MySQLMasterPos ) ) {
 870                         throw new InvalidArgumentException( "Position not an instance of MySQLMasterPos" );
 871                 }
 872
 873                 if ( $this->getLBInfo( 'is static' ) === true ) {
 874                         return 0; // this is a copy of a read-only dataset with no master DB
 875                 } elseif ( $this->lastKnownReplicaPos && $this->lastKnownReplicaPos->hasReached( $pos ) ) {
 876                         return 0; // already reached this point for sure
 877                 }
 878
 879                 // Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 880                 if ( $pos->getGTIDs() ) {
 881                         // Ignore GTIDs from domains exclusive to the master DB (presumably inactive)
 882                         $rpos = $this->getReplicaPos();
 883                         $gtidsWait = $rpos ? MySQLMasterPos::getCommonDomainGTIDs( $pos, $rpos ) : [];
 884                         if ( !$gtidsWait ) {
 885                                 $this->queryLogger->error(
 886                                         "No GTIDs with the same domain between master ($pos) and replica ($rpos)",
 887                                         $this->getLogContext( [
 888                                                 'method' => __METHOD__,
 889                                         ] )
 890                                 );
 891
 892                                 return -1; // $pos is from the wrong cluster?
 893                         }
 894                         // Wait on the GTID set (MariaDB only)
 895                         $gtidArg = $this->addQuotes( implode( ',', $gtidsWait ) );
 896                         if ( strpos( $gtidArg, ':' ) !== false ) {
 897                                 // MySQL GTIDs, e.g "source_id:transaction_id"
 898                                 $sql = "SELECT WAIT_FOR_EXECUTED_GTID_SET($gtidArg, $timeout)";
 899                         } else {
 900                                 // MariaDB GTIDs, e.g."domain:server:sequence"
 901                                 $sql = "SELECT MASTER_GTID_WAIT($gtidArg, $timeout)";
 902                         }
 903                 } else {
 904                         // Wait on the binlog coordinates
 905                         $encFile = $this->addQuotes( $pos->getLogFile() );
 906                         $encPos = intval( $pos->getLogPosition()[$pos::CORD_EVENT] );
 907                         $sql = "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)";
 908                 }
 909
 910                 list( $res, $err ) = $this->executeQuery( $sql, __METHOD__, self::QUERY_IGNORE_DBO_TRX );
 911                 $row = $res ? $this->fetchRow( $res ) : false;
 912                 if ( !$row ) {
 913                         throw new DBExpectedError( $this, "Replication wait failed: {$err}" );
 914                 }
 915
 916                 // Result can be NULL (error), -1 (timeout), or 0+ per the MySQL manual
 917                 $status = ( $row[0] !== null ) ? intval( $row[0] ) : null;
 918                 if ( $status === null ) {
 919                         if ( !$pos->getGTIDs() ) {
 920                                 // T126436: jobs programmed to wait on master positions might be referencing
 921                                 // binlogs with an old master hostname; this makes MASTER_POS_WAIT() return null.
 922                                 // Try to detect this case and treat the replica DB as having reached the given
 923                                 // position (any master switchover already requires that the new master be caught
 924                                 // up before the switch).
 925                                 $replicationPos = $this->getReplicaPos();
 926                                 if ( $replicationPos && !$replicationPos->channelsMatch( $pos ) ) {
 927                                         $this->lastKnownReplicaPos = $replicationPos;
 928                                         $status = 0;
 929                                 }
 930                         }
 931                 } elseif ( $status >= 0 ) {
 932                         // Remember that this position was reached to save queries next time
 933                         $this->lastKnownReplicaPos = $pos;
 934                 }
 935
 936                 return $status;
 937         }
 938
 939         /**
 940          * Get the position of the master from SHOW SLAVE STATUS
 941          *
 942          * @return MySQLMasterPos|bool
 943          */
 944         public function getReplicaPos() {
 945                 $now = microtime( true ); // as-of-time *before* fetching GTID variables
 946
 947                 if ( $this->useGTIDs() ) {
 948                         // Try to use GTIDs, fallbacking to binlog positions if not possible
 949                         $data = $this->getServerGTIDs( __METHOD__ );
 950                         // Use gtid_slave_pos for MariaDB and gtid_executed for MySQL
 951                         foreach ( [ 'gtid_slave_pos', 'gtid_executed' ] as $name ) {
 952                                 if ( isset( $data[$name] ) && strlen( $data[$name] ) ) {
 953                                         return new MySQLMasterPos( $data[$name], $now );
 954                                 }
 955                         }
 956                 }
 957
 958                 $data = $this->getServerRoleStatus( 'SLAVE', __METHOD__ );
 959                 if ( $data && strlen( $data['Relay_Master_Log_File'] ) ) {
 960                         return new MySQLMasterPos(
 961                                 "{$data['Relay_Master_Log_File']}/{$data['Exec_Master_Log_Pos']}",
 962                                 $now
 963                         );
 964                 }
 965
 966                 return false;
 967         }
 968
 969         /**
 970          * Get the position of the master from SHOW MASTER STATUS
 971          *
 972          * @return MySQLMasterPos|bool
 973          */
 974         public function getMasterPos() {
 975                 $now = microtime( true ); // as-of-time *before* fetching GTID variables
 976
 977                 $pos = false;
 978                 if ( $this->useGTIDs() ) {
 979                         // Try to use GTIDs, fallbacking to binlog positions if not possible
 980                         $data = $this->getServerGTIDs( __METHOD__ );
 981                         // Use gtid_binlog_pos for MariaDB and gtid_executed for MySQL
 982                         foreach ( [ 'gtid_binlog_pos', 'gtid_executed' ] as $name ) {
 983                                 if ( isset( $data[$name] ) && strlen( $data[$name] ) ) {
 984                                         $pos = new MySQLMasterPos( $data[$name], $now );
 985                                         break;
 986                                 }
 987                         }
 988                         // Filter domains that are inactive or not relevant to the session
 989                         if ( $pos ) {
 990                                 $pos->setActiveOriginServerId( $this->getServerId() );
 991                                 $pos->setActiveOriginServerUUID( $this->getServerUUID() );
 992                                 if ( isset( $data['gtid_domain_id'] ) ) {
 993                                         $pos->setActiveDomain( $data['gtid_domain_id'] );
 994                                 }
 995                         }
 996                 }
 997
 998                 if ( !$pos ) {
 999                         $data = $this->getServerRoleStatus( 'MASTER', __METHOD__ );
1000                         if ( $data && strlen( $data['File'] ) ) {
1001                                 $pos = new MySQLMasterPos( "{$data['File']}/{$data['Position']}", $now );
1002                         }
1003                 }
1004
1005                 return $pos;
1006         }
1007
1008         /**
1009          * @return int
1010          * @throws DBQueryError If the variable doesn't exist for some reason
1011          */
1012         protected function getServerId() {
1013                 $fname = __METHOD__;
1014                 return $this->srvCache->getWithSetCallback(
1015                         $this->srvCache->makeGlobalKey( 'mysql-server-id', $this->getServer() ),
1016                         self::SERVER_ID_CACHE_TTL,
1017                         function () use ( $fname ) {
1018                                 $flags = self::QUERY_IGNORE_DBO_TRX;
1019                                 $res = $this->query( "SELECT @@server_id AS id", $fname, $flags );
1020
1021                                 return intval( $this->fetchObject( $res )->id );
1022                         }
1023                 );
1024         }
1025
1026         /**
1027          * @return string|null
1028          */
1029         protected function getServerUUID() {
1030                 $fname = __METHOD__;
1031                 return $this->srvCache->getWithSetCallback(
1032                         $this->srvCache->makeGlobalKey( 'mysql-server-uuid', $this->getServer() ),
1033                         self::SERVER_ID_CACHE_TTL,
1034                         function () use ( $fname ) {
1035                                 $flags = self::QUERY_IGNORE_DBO_TRX;
1036                                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'server_uuid'", $fname, $flags );
1037                                 $row = $this->fetchObject( $res );
1038
1039                                 return $row ? $row->Value : null;
1040                         }
1041                 );
1042         }
1043
1044         /**
1045          * @param string $fname
1046          * @return string[]
1047          */
1048         protected function getServerGTIDs( $fname = __METHOD__ ) {
1049                 $map = [];
1050
1051                 $flags = self::QUERY_IGNORE_DBO_TRX;
1052                 // Get global-only variables like gtid_executed
1053                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_%'", $fname, $flags );
1054                 foreach ( $res as $row ) {
1055                         $map[$row->Variable_name] = $row->Value;
1056                 }
1057                 // Get session-specific (e.g. gtid_domain_id since that is were writes will log)
1058                 $res = $this->query( "SHOW SESSION VARIABLES LIKE 'gtid_%'", $fname, $flags );
1059                 foreach ( $res as $row ) {
1060                         $map[$row->Variable_name] = $row->Value;
1061                 }
1062
1063                 return $map;
1064         }
1065
1066         /**
1067          * @param string $role One of "MASTER"/"SLAVE"
1068          * @param string $fname
1069          * @return string[] Latest available server status row
1070          */
1071         protected function getServerRoleStatus( $role, $fname = __METHOD__ ) {
1072                 $flags = self::QUERY_IGNORE_DBO_TRX;
1073
1074                 return $this->query( "SHOW $role STATUS", $fname, $flags )->fetchRow() ?: [];
1075         }
1076
1077         public function serverIsReadOnly() {
1078                 $flags = self::QUERY_IGNORE_DBO_TRX;
1079                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'read_only'", __METHOD__, $flags );
1080                 $row = $this->fetchObject( $res );
1081
1082                 return $row ? ( strtolower( $row->Value ) === 'on' ) : false;
1083         }
1084
1085         /**
1086          * @param string $index
1087          * @return string
1088          */
1089         function useIndexClause( $index ) {
1090                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
1091         }
1092
1093         /**
1094          * @param string $index
1095          * @return string
1096          */
1097         function ignoreIndexClause( $index ) {
1098                 return "IGNORE INDEX (" . $this->indexName( $index ) . ")";
1099         }
1100
1101         /**
1102          * @return string
1103          */
1104         function lowPriorityOption() {
1105                 return 'LOW_PRIORITY';
1106         }
1107
1108         /**
1109          * @return string
1110          */
1111         public function getSoftwareLink() {
1112                 // MariaDB includes its name in its version string; this is how MariaDB's version of
1113                 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
1114                 // in libmysql/libmysql.c).
1115                 $version = $this->getServerVersion();
1116                 if ( strpos( $version, 'MariaDB' ) !== false || strpos( $version, '-maria-' ) !== false ) {
1117                         return '[{{int:version-db-mariadb-url}} MariaDB]';
1118                 }
1119
1120                 // Percona Server's version suffix is not very distinctive, and @@version_comment
1121                 // doesn't give the necessary info for source builds, so assume the server is MySQL.
1122                 // (Even Percona's version of mysql doesn't try to make the distinction.)
1123                 return '[{{int:version-db-mysql-url}} MySQL]';
1124         }
1125
1126         /**
1127          * @return string
1128          */
1129         public function getServerVersion() {
1130                 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
1131                 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
1132                 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
1133                 if ( $this->serverVersion === null ) {
1134                         $this->serverVersion = $this->selectField( '', 'VERSION()', '', __METHOD__ );
1135                 }
1136                 return $this->serverVersion;
1137         }
1138
1139         /**
1140          * @param array $options
1141          */
1142         public function setSessionOptions( array $options ) {
1143                 if ( isset( $options['connTimeout'] ) ) {
1144                         $flags = self::QUERY_IGNORE_DBO_TRX;
1145                         $timeout = (int)$options['connTimeout'];
1146                         $this->query( "SET net_read_timeout=$timeout", __METHOD__, $flags );
1147                         $this->query( "SET net_write_timeout=$timeout", __METHOD__, $flags );
1148                 }
1149         }
1150
1151         /**
1152          * @param string &$sql
1153          * @param string &$newLine
1154          * @return bool
1155          */
1156         public function streamStatementEnd( &$sql, &$newLine ) {
1157                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
1158                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
1159                         $this->delimiter = $m[1];
1160                         $newLine = '';
1161                 }
1162
1163                 return parent::streamStatementEnd( $sql, $newLine );
1164         }
1165
1166         /**
1167          * Check to see if a named lock is available. This is non-blocking.
1168          *
1169          * @param string $lockName Name of lock to poll
1170          * @param string $method Name of method calling us
1171          * @return bool
1172          * @since 1.20
1173          */
1174         public function lockIsFree( $lockName, $method ) {
1175                 if ( !parent::lockIsFree( $lockName, $method ) ) {
1176                         return false; // already held
1177                 }
1178
1179                 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1180
1181                 $flags = self::QUERY_IGNORE_DBO_TRX;
1182                 $res = $this->query( "SELECT IS_FREE_LOCK($encName) AS lockstatus", $method, $flags );
1183                 $row = $this->fetchObject( $res );
1184
1185                 return ( $row->lockstatus == 1 );
1186         }
1187
1188         /**
1189          * @param string $lockName
1190          * @param string $method
1191          * @param int $timeout
1192          * @return bool
1193          */
1194         public function lock( $lockName, $method, $timeout = 5 ) {
1195                 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1196
1197                 $flags = self::QUERY_IGNORE_DBO_TRX;
1198                 $res = $this->query( "SELECT GET_LOCK($encName, $timeout) AS lockstatus", $method, $flags );
1199                 $row = $this->fetchObject( $res );
1200
1201                 if ( $row->lockstatus == 1 ) {
1202                         parent::lock( $lockName, $method, $timeout ); // record
1203                         return true;
1204                 }
1205
1206                 $this->queryLogger->info( __METHOD__ . " failed to acquire lock '{lockname}'",
1207                         [ 'lockname' => $lockName ] );
1208
1209                 return false;
1210         }
1211
1212         /**
1213          * FROM MYSQL DOCS:
1214          * https://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
1215          * @param string $lockName
1216          * @param string $method
1217          * @return bool
1218          */
1219         public function unlock( $lockName, $method ) {
1220                 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1221
1222                 $flags = self::QUERY_IGNORE_DBO_TRX;
1223                 $res = $this->query( "SELECT RELEASE_LOCK($encName) as lockstatus", $method, $flags );
1224                 $row = $this->fetchObject( $res );
1225
1226                 if ( $row->lockstatus == 1 ) {
1227                         parent::unlock( $lockName, $method ); // record
1228                         return true;
1229                 }
1230
1231                 $this->queryLogger->warning( __METHOD__ . " failed to release lock '$lockName'\n" );
1232
1233                 return false;
1234         }
1235
1236         private function makeLockName( $lockName ) {
1237                 // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1238                 // Newer version enforce a 64 char length limit.
1239                 return ( strlen( $lockName ) > 64 ) ? sha1( $lockName ) : $lockName;
1240         }
1241
1242         public function namedLocksEnqueue() {
1243                 return true;
1244         }
1245
1246         public function tableLocksHaveTransactionScope() {
1247                 return false; // tied to TCP connection
1248         }
1249
1250         protected function doLockTables( array $read, array $write, $method ) {
1251                 $items = [];
1252                 foreach ( $write as $table ) {
1253                         $items[] = $this->tableName( $table ) . ' WRITE';
1254                 }
1255                 foreach ( $read as $table ) {
1256                         $items[] = $this->tableName( $table ) . ' READ';
1257                 }
1258
1259                 $sql = "LOCK TABLES " . implode( ',', $items );
1260                 $this->query( $sql, $method, self::QUERY_IGNORE_DBO_TRX );
1261
1262                 return true;
1263         }
1264
1265         protected function doUnlockTables( $method ) {
1266                 $this->query( "UNLOCK TABLES", $method, self::QUERY_IGNORE_DBO_TRX );
1267
1268                 return true;
1269         }
1270
1271         /**
1272          * @param bool $value
1273          */
1274         public function setBigSelects( $value = true ) {
1275                 if ( $value === 'default' ) {
1276                         if ( $this->defaultBigSelects === null ) {
1277                                 # Function hasn't been called before so it must already be set to the default
1278                                 return;
1279                         } else {
1280                                 $value = $this->defaultBigSelects;
1281                         }
1282                 } elseif ( $this->defaultBigSelects === null ) {
1283                         $this->defaultBigSelects =
1284                                 (bool)$this->selectField( false, '@@sql_big_selects', '', __METHOD__ );
1285                 }
1286                 $encValue = $value ? '1' : '0';
1287                 $this->query( "SET sql_big_selects=$encValue", __METHOD__, self::QUERY_IGNORE_DBO_TRX );
1288         }
1289
1290         /**
1291          * DELETE where the condition is a join. MySql uses multi-table deletes.
1292          * @param string $delTable
1293          * @param string $joinTable
1294          * @param string $delVar
1295          * @param string $joinVar
1296          * @param array|string $conds
1297          * @param bool|string $fname
1298          * @throws DBUnexpectedError
1299          */
1300         public function deleteJoin(
1301                 $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__
1302         ) {
1303                 if ( !$conds ) {
1304                         throw new DBUnexpectedError( $this, __METHOD__ . ' called with empty $conds' );
1305                 }
1306
1307                 $delTable = $this->tableName( $delTable );
1308                 $joinTable = $this->tableName( $joinTable );
1309                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1310
1311                 if ( $conds != '*' ) {
1312                         $sql .= ' AND ' . $this->makeList( $conds, self::LIST_AND );
1313                 }
1314
1315                 $this->query( $sql, $fname );
1316         }
1317
1318         public function upsert(
1319                 $table, array $rows, $uniqueIndexes, array $set, $fname = __METHOD__
1320         ) {
1321                 if ( $rows === [] ) {
1322                         return true; // nothing to do
1323                 }
1324
1325                 if ( !is_array( reset( $rows ) ) ) {
1326                         $rows = [ $rows ];
1327                 }
1328
1329                 $table = $this->tableName( $table );
1330                 $columns = array_keys( $rows[0] );
1331
1332                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
1333                 $rowTuples = [];
1334                 foreach ( $rows as $row ) {
1335                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
1336                 }
1337                 $sql .= implode( ',', $rowTuples );
1338                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, self::LIST_SET );
1339
1340                 $this->query( $sql, $fname );
1341
1342                 return true;
1343         }
1344
1345         /**
1346          * Determines how long the server has been up
1347          *
1348          * @return int
1349          */
1350         public function getServerUptime() {
1351                 $vars = $this->getMysqlStatus( 'Uptime' );
1352
1353                 return (int)$vars['Uptime'];
1354         }
1355
1356         /**
1357          * Determines if the last failure was due to a deadlock
1358          *
1359          * @return bool
1360          */
1361         public function wasDeadlock() {
1362                 return $this->lastErrno() == 1213;
1363         }
1364
1365         /**
1366          * Determines if the last failure was due to a lock timeout
1367          *
1368          * @return bool
1369          */
1370         public function wasLockTimeout() {
1371                 return $this->lastErrno() == 1205;
1372         }
1373
1374         /**
1375          * Determines if the last failure was due to the database being read-only.
1376          *
1377          * @return bool
1378          */
1379         public function wasReadOnlyError() {
1380                 return $this->lastErrno() == 1223 ||
1381                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1382         }
1383
1384         public function wasConnectionError( $errno ) {
1385                 return $errno == 2013 || $errno == 2006;
1386         }
1387
1388         protected function wasKnownStatementRollbackError() {
1389                 $errno = $this->lastErrno();
1390
1391                 if ( $errno === 1205 ) { // lock wait timeout
1392                         // Note that this is uncached to avoid stale values of SET is used
1393                         $row = $this->selectRow(
1394                                 false,
1395                                 [ 'innodb_rollback_on_timeout' => '@@innodb_rollback_on_timeout' ],
1396                                 [],
1397                                 __METHOD__
1398                         );
1399                         // https://dev.mysql.com/doc/refman/5.7/en/innodb-error-handling.html
1400                         // https://dev.mysql.com/doc/refman/5.5/en/innodb-parameters.html
1401                         return $row->innodb_rollback_on_timeout ? false : true;
1402                 }
1403
1404                 // See https://dev.mysql.com/doc/refman/5.5/en/error-messages-server.html
1405                 return in_array( $errno, [ 1022, 1062, 1216, 1217, 1137, 1146, 1051, 1054 ], true );
1406         }
1407
1408         /**
1409          * @param string $oldName
1410          * @param string $newName
1411          * @param bool $temporary
1412          * @param string $fname
1413          * @return bool
1414          */
1415         public function duplicateTableStructure(
1416                 $oldName, $newName, $temporary = false, $fname = __METHOD__
1417         ) {
1418                 $tmp = $temporary ? 'TEMPORARY ' : '';
1419                 $newName = $this->addIdentifierQuotes( $newName );
1420                 $oldName = $this->addIdentifierQuotes( $oldName );
1421                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1422
1423                 return $this->query( $query, $fname, $this::QUERY_PSEUDO_PERMANENT );
1424         }
1425
1426         /**
1427          * List all tables on the database
1428          *
1429          * @param string|null $prefix Only show tables with this prefix, e.g. mw_
1430          * @param string $fname Calling function name
1431          * @return array
1432          */
1433         public function listTables( $prefix = null, $fname = __METHOD__ ) {
1434                 $result = $this->query( "SHOW TABLES", $fname );
1435
1436                 $endArray = [];
1437
1438                 foreach ( $result as $table ) {
1439                         $vars = get_object_vars( $table );
1440                         $table = array_pop( $vars );
1441
1442                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1443                                 $endArray[] = $table;
1444                         }
1445                 }
1446
1447                 return $endArray;
1448         }
1449
1450         /**
1451          * @param string $tableName
1452          * @param string $fName
1453          * @return bool|IResultWrapper
1454          */
1455         public function dropTable( $tableName, $fName = __METHOD__ ) {
1456                 if ( !$this->tableExists( $tableName, $fName ) ) {
1457                         return false;
1458                 }
1459
1460                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1461         }
1462
1463         /**
1464          * Get status information from SHOW STATUS in an associative array
1465          *
1466          * @param string $which
1467          * @return array
1468          */
1469         private function getMysqlStatus( $which = "%" ) {
1470                 $flags = self::QUERY_IGNORE_DBO_TRX;
1471                 $res = $this->query( "SHOW STATUS LIKE '{$which}'", __METHOD__, $flags );
1472                 $status = [];
1473
1474                 foreach ( $res as $row ) {
1475                         $status[$row->Variable_name] = $row->Value;
1476                 }
1477
1478                 return $status;
1479         }
1480
1481         /**
1482          * Lists VIEWs in the database
1483          *
1484          * @param string|null $prefix Only show VIEWs with this prefix, eg.
1485          * unit_test_, or $wgDBprefix. Default: null, would return all views.
1486          * @param string $fname Name of calling function
1487          * @return array
1488          * @since 1.22
1489          */
1490         public function listViews( $prefix = null, $fname = __METHOD__ ) {
1491                 // The name of the column containing the name of the VIEW
1492                 $propertyName = 'Tables_in_' . $this->getDBname();
1493
1494                 // Query for the VIEWS
1495                 $res = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1496                 $allViews = [];
1497                 foreach ( $res as $row ) {
1498                         array_push( $allViews, $row->$propertyName );
1499                 }
1500
1501                 if ( is_null( $prefix ) || $prefix === '' ) {
1502                         return $allViews;
1503                 }
1504
1505                 $filteredViews = [];
1506                 foreach ( $allViews as $viewName ) {
1507                         // Does the name of this VIEW start with the table-prefix?
1508                         if ( strpos( $viewName, $prefix ) === 0 ) {
1509                                 array_push( $filteredViews, $viewName );
1510                         }
1511                 }
1512
1513                 return $filteredViews;
1514         }
1515
1516         /**
1517          * Differentiates between a TABLE and a VIEW.
1518          *
1519          * @param string $name Name of the TABLE/VIEW to test
1520          * @param string|null $prefix
1521          * @return bool
1522          * @since 1.22
1523          */
1524         public function isView( $name, $prefix = null ) {
1525                 return in_array( $name, $this->listViews( $prefix ) );
1526         }
1527
1528         protected function isTransactableQuery( $sql ) {
1529                 return parent::isTransactableQuery( $sql ) &&
1530                         !preg_match( '/^SELECT\s+(GET|RELEASE|IS_FREE)_LOCK\(/', $sql );
1531         }
1532
1533         public function buildStringCast( $field ) {
1534                 return "CAST( $field AS BINARY )";
1535         }
1536
1537         /**
1538          * @param string $field Field or column to cast
1539          * @return string
1540          */
1541         public function buildIntegerCast( $field ) {
1542                 return 'CAST( ' . $field . ' AS SIGNED )';
1543         }
1544
1545         /*
1546          * @return bool Whether GTID support is used (mockable for testing)
1547          */
1548         protected function useGTIDs() {
1549                 return $this->useGTIDs;
1550         }
1551 }
1552
1553 /**
1554  * @deprecated since 1.29
1555  */
1556 class_alias( DatabaseMysqlBase::class, 'DatabaseMysqlBase' );