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;
  28 use InvalidArgumentException;
  29 use Exception;
  30 use stdClass;
  31
  32 /**
  33  * Database abstraction object for MySQL.
  34  * Defines methods independent on used MySQL extension.
  35  *
  36  * @ingroup Database
  37  * @since 1.22
  38  * @see Database
  39  */
  40 abstract class DatabaseMysqlBase extends Database {
  41         /** @var MysqlMasterPos */
  42         protected $lastKnownReplicaPos;
  43         /** @var string Method to detect replica DB lag */
  44         protected $lagDetectionMethod;
  45         /** @var array Method to detect replica DB lag */
  46         protected $lagDetectionOptions = [];
  47         /** @var bool bool Whether to use GTID methods */
  48         protected $useGTIDs = false;
  49         /** @var string|null */
  50         protected $sslKeyPath;
  51         /** @var string|null */
  52         protected $sslCertPath;
  53         /** @var string|null */
  54         protected $sslCAFile;
  55         /** @var string|null */
  56         protected $sslCAPath;
  57         /** @var string[]|null */
  58         protected $sslCiphers;
  59         /** @var string sql_mode value to send on connection */
  60         protected $sqlMode;
  61         /** @var bool Use experimental UTF-8 transmission encoding */
  62         protected $utf8Mode;
  63         /** @var bool|null */
  64         protected $defaultBigSelects = null;
  65
  66         /** @var string|null */
  67         private $serverVersion = null;
  68         /** @var bool|null */
  69         private $insertSelectIsSafe = null;
  70         /** @var stdClass|null */
  71         private $replicationInfoRow = null;
  72
  73         // Cache getServerId() for 24 hours
  74         const SERVER_ID_CACHE_TTL = 86400;
  75
  76         /**
  77          * Additional $params include:
  78          *   - lagDetectionMethod : set to one of (Seconds_Behind_Master,pt-heartbeat).
  79          *       pt-heartbeat assumes the table is at heartbeat.heartbeat
  80          *       and uses UTC timestamps in the heartbeat.ts column.
  81          *       (https://www.percona.com/doc/percona-toolkit/2.2/pt-heartbeat.html)
  82          *   - lagDetectionOptions : if using pt-heartbeat, this can be set to an array map to change
  83          *       the default behavior. Normally, the heartbeat row with the server
  84          *       ID of this server's master will be used. Set the "conds" field to
  85          *       override the query conditions, e.g. ['shard' => 's1'].
  86          *   - useGTIDs : use GTID methods like MASTER_GTID_WAIT() when possible.
  87          *   - insertSelectIsSafe : force that native INSERT SELECT is or is not safe [default: null]
  88          *   - sslKeyPath : path to key file [default: null]
  89          *   - sslCertPath : path to certificate file [default: null]
  90          *   - sslCAFile: path to a single certificate authority PEM file [default: null]
  91          *   - sslCAPath : parth to certificate authority PEM directory [default: null]
  92          *   - sslCiphers : array list of allowable ciphers [default: null]
  93          * @param array $params
  94          */
  95         function __construct( array $params ) {
  96                 $this->lagDetectionMethod = isset( $params['lagDetectionMethod'] )
  97                         ? $params['lagDetectionMethod']
  98                         : 'Seconds_Behind_Master';
  99                 $this->lagDetectionOptions = isset( $params['lagDetectionOptions'] )
 100                         ? $params['lagDetectionOptions']
 101                         : [];
 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 = isset( $params['sqlMode'] ) ? $params['sqlMode'] : '';
 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         /**
 125          * @param string $server
 126          * @param string $user
 127          * @param string $password
 128          * @param string $dbName
 129          * @throws Exception|DBConnectionError
 130          * @return bool
 131          */
 132         public function open( $server, $user, $password, $dbName ) {
 133                 # Close/unset connection handle
 134                 $this->close();
 135
 136                 $this->server = $server;
 137                 $this->user = $user;
 138                 $this->password = $password;
 139                 $this->dbName = $dbName;
 140
 141                 $this->installErrorHandler();
 142                 try {
 143                         $this->conn = $this->mysqlConnect( $this->server );
 144                 } catch ( Exception $ex ) {
 145                         $this->restoreErrorHandler();
 146                         throw $ex;
 147                 }
 148                 $error = $this->restoreErrorHandler();
 149
 150                 # Always log connection errors
 151                 if ( !$this->conn ) {
 152                         if ( !$error ) {
 153                                 $error = $this->lastError();
 154                         }
 155                         $this->connLogger->error(
 156                                 "Error connecting to {db_server}: {error}",
 157                                 $this->getLogContext( [
 158                                         'method' => __METHOD__,
 159                                         'error' => $error,
 160                                 ] )
 161                         );
 162                         $this->connLogger->debug( "DB connection error\n" .
 163                                 "Server: $server, User: $user, Password: " .
 164                                 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
 165
 166                         $this->reportConnectionError( $error );
 167                 }
 168
 169                 if ( strlen( $dbName ) ) {
 170                         Wikimedia\suppressWarnings();
 171                         $success = $this->selectDB( $dbName );
 172                         Wikimedia\restoreWarnings();
 173                         if ( !$success ) {
 174                                 $this->queryLogger->error(
 175                                         "Error selecting database {db_name} on server {db_server}",
 176                                         $this->getLogContext( [
 177                                                 'method' => __METHOD__,
 178                                         ] )
 179                                 );
 180                                 $this->queryLogger->debug(
 181                                         "Error selecting database $dbName on server {$this->server}" );
 182
 183                                 $this->reportConnectionError( "Error selecting database $dbName" );
 184                         }
 185                 }
 186
 187                 // Tell the server what we're communicating with
 188                 if ( !$this->connectInitCharset() ) {
 189                         $this->reportConnectionError( "Error setting character set" );
 190                 }
 191
 192                 // Abstract over any insane MySQL defaults
 193                 $set = [ 'group_concat_max_len = 262144' ];
 194                 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
 195                 if ( is_string( $this->sqlMode ) ) {
 196                         $set[] = 'sql_mode = ' . $this->addQuotes( $this->sqlMode );
 197                 }
 198                 // Set any custom settings defined by site config
 199                 // (e.g. https://dev.mysql.com/doc/refman/4.1/en/innodb-parameters.html)
 200                 foreach ( $this->sessionVars as $var => $val ) {
 201                         // Escape strings but not numbers to avoid MySQL complaining
 202                         if ( !is_int( $val ) && !is_float( $val ) ) {
 203                                 $val = $this->addQuotes( $val );
 204                         }
 205                         $set[] = $this->addIdentifierQuotes( $var ) . ' = ' . $val;
 206                 }
 207
 208                 if ( $set ) {
 209                         // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
 210                         $success = $this->doQuery( 'SET ' . implode( ', ', $set ) );
 211                         if ( !$success ) {
 212                                 $this->queryLogger->error(
 213                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)',
 214                                         $this->getLogContext( [
 215                                                 'method' => __METHOD__,
 216                                         ] )
 217                                 );
 218                                 $this->reportConnectionError(
 219                                         'Error setting MySQL variables on server {db_server} (check $wgSQLMode)' );
 220                         }
 221                 }
 222
 223                 $this->opened = true;
 224
 225                 return true;
 226         }
 227
 228         /**
 229          * Set the character set information right after connection
 230          * @return bool
 231          */
 232         protected function connectInitCharset() {
 233                 if ( $this->utf8Mode ) {
 234                         // Tell the server we're communicating with it in UTF-8.
 235                         // This may engage various charset conversions.
 236                         return $this->mysqlSetCharset( 'utf8' );
 237                 } else {
 238                         return $this->mysqlSetCharset( 'binary' );
 239                 }
 240         }
 241
 242         /**
 243          * Open a connection to a MySQL server
 244          *
 245          * @param string $realServer
 246          * @return mixed Raw connection
 247          * @throws DBConnectionError
 248          */
 249         abstract protected function mysqlConnect( $realServer );
 250
 251         /**
 252          * Set the character set of the MySQL link
 253          *
 254          * @param string $charset
 255          * @return bool
 256          */
 257         abstract protected function mysqlSetCharset( $charset );
 258
 259         /**
 260          * @param ResultWrapper|resource $res
 261          * @throws DBUnexpectedError
 262          */
 263         public function freeResult( $res ) {
 264                 if ( $res instanceof ResultWrapper ) {
 265                         $res = $res->result;
 266                 }
 267                 Wikimedia\suppressWarnings();
 268                 $ok = $this->mysqlFreeResult( $res );
 269                 Wikimedia\restoreWarnings();
 270                 if ( !$ok ) {
 271                         throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
 272                 }
 273         }
 274
 275         /**
 276          * Free result memory
 277          *
 278          * @param resource $res Raw result
 279          * @return bool
 280          */
 281         abstract protected function mysqlFreeResult( $res );
 282
 283         /**
 284          * @param ResultWrapper|resource $res
 285          * @return stdClass|bool
 286          * @throws DBUnexpectedError
 287          */
 288         public function fetchObject( $res ) {
 289                 if ( $res instanceof ResultWrapper ) {
 290                         $res = $res->result;
 291                 }
 292                 Wikimedia\suppressWarnings();
 293                 $row = $this->mysqlFetchObject( $res );
 294                 Wikimedia\restoreWarnings();
 295
 296                 $errno = $this->lastErrno();
 297                 // Unfortunately, mysql_fetch_object does not reset the last errno.
 298                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 299                 // these are the only errors mysql_fetch_object can cause.
 300                 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 301                 if ( $errno == 2000 || $errno == 2013 ) {
 302                         throw new DBUnexpectedError(
 303                                 $this,
 304                                 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
 305                         );
 306                 }
 307
 308                 return $row;
 309         }
 310
 311         /**
 312          * Fetch a result row as an object
 313          *
 314          * @param resource $res Raw result
 315          * @return stdClass
 316          */
 317         abstract protected function mysqlFetchObject( $res );
 318
 319         /**
 320          * @param ResultWrapper|resource $res
 321          * @return array|bool
 322          * @throws DBUnexpectedError
 323          */
 324         public function fetchRow( $res ) {
 325                 if ( $res instanceof ResultWrapper ) {
 326                         $res = $res->result;
 327                 }
 328                 Wikimedia\suppressWarnings();
 329                 $row = $this->mysqlFetchArray( $res );
 330                 Wikimedia\restoreWarnings();
 331
 332                 $errno = $this->lastErrno();
 333                 // Unfortunately, mysql_fetch_array does not reset the last errno.
 334                 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
 335                 // these are the only errors mysql_fetch_array can cause.
 336                 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 337                 if ( $errno == 2000 || $errno == 2013 ) {
 338                         throw new DBUnexpectedError(
 339                                 $this,
 340                                 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
 341                         );
 342                 }
 343
 344                 return $row;
 345         }
 346
 347         /**
 348          * Fetch a result row as an associative and numeric array
 349          *
 350          * @param resource $res Raw result
 351          * @return array
 352          */
 353         abstract protected function mysqlFetchArray( $res );
 354
 355         /**
 356          * @throws DBUnexpectedError
 357          * @param ResultWrapper|resource $res
 358          * @return int
 359          */
 360         function numRows( $res ) {
 361                 if ( $res instanceof ResultWrapper ) {
 362                         $res = $res->result;
 363                 }
 364                 Wikimedia\suppressWarnings();
 365                 $n = $this->mysqlNumRows( $res );
 366                 Wikimedia\restoreWarnings();
 367
 368                 // Unfortunately, mysql_num_rows does not reset the last errno.
 369                 // We are not checking for any errors here, since
 370                 // these are no errors mysql_num_rows can cause.
 371                 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
 372                 // See https://phabricator.wikimedia.org/T44430
 373                 return $n;
 374         }
 375
 376         /**
 377          * Get number of rows in result
 378          *
 379          * @param resource $res Raw result
 380          * @return int
 381          */
 382         abstract protected function mysqlNumRows( $res );
 383
 384         /**
 385          * @param ResultWrapper|resource $res
 386          * @return int
 387          */
 388         public function numFields( $res ) {
 389                 if ( $res instanceof ResultWrapper ) {
 390                         $res = $res->result;
 391                 }
 392
 393                 return $this->mysqlNumFields( $res );
 394         }
 395
 396         /**
 397          * Get number of fields in result
 398          *
 399          * @param resource $res Raw result
 400          * @return int
 401          */
 402         abstract protected function mysqlNumFields( $res );
 403
 404         /**
 405          * @param ResultWrapper|resource $res
 406          * @param int $n
 407          * @return string
 408          */
 409         public function fieldName( $res, $n ) {
 410                 if ( $res instanceof ResultWrapper ) {
 411                         $res = $res->result;
 412                 }
 413
 414                 return $this->mysqlFieldName( $res, $n );
 415         }
 416
 417         /**
 418          * Get the name of the specified field in a result
 419          *
 420          * @param ResultWrapper|resource $res
 421          * @param int $n
 422          * @return string
 423          */
 424         abstract protected function mysqlFieldName( $res, $n );
 425
 426         /**
 427          * mysql_field_type() wrapper
 428          * @param ResultWrapper|resource $res
 429          * @param int $n
 430          * @return string
 431          */
 432         public function fieldType( $res, $n ) {
 433                 if ( $res instanceof ResultWrapper ) {
 434                         $res = $res->result;
 435                 }
 436
 437                 return $this->mysqlFieldType( $res, $n );
 438         }
 439
 440         /**
 441          * Get the type of the specified field in a result
 442          *
 443          * @param ResultWrapper|resource $res
 444          * @param int $n
 445          * @return string
 446          */
 447         abstract protected function mysqlFieldType( $res, $n );
 448
 449         /**
 450          * @param ResultWrapper|resource $res
 451          * @param int $row
 452          * @return bool
 453          */
 454         public function dataSeek( $res, $row ) {
 455                 if ( $res instanceof ResultWrapper ) {
 456                         $res = $res->result;
 457                 }
 458
 459                 return $this->mysqlDataSeek( $res, $row );
 460         }
 461
 462         /**
 463          * Move internal result pointer
 464          *
 465          * @param ResultWrapper|resource $res
 466          * @param int $row
 467          * @return bool
 468          */
 469         abstract protected function mysqlDataSeek( $res, $row );
 470
 471         /**
 472          * @return string
 473          */
 474         public function lastError() {
 475                 if ( $this->conn ) {
 476                         # Even if it's non-zero, it can still be invalid
 477                         Wikimedia\suppressWarnings();
 478                         $error = $this->mysqlError( $this->conn );
 479                         if ( !$error ) {
 480                                 $error = $this->mysqlError();
 481                         }
 482                         Wikimedia\restoreWarnings();
 483                 } else {
 484                         $error = $this->mysqlError();
 485                 }
 486                 if ( $error ) {
 487                         $error .= ' (' . $this->server . ')';
 488                 }
 489
 490                 return $error;
 491         }
 492
 493         /**
 494          * Returns the text of the error message from previous MySQL operation
 495          *
 496          * @param resource $conn Raw connection
 497          * @return string
 498          */
 499         abstract protected function mysqlError( $conn = null );
 500
 501         protected function wasQueryTimeout( $error, $errno ) {
 502                 return $errno == 2062;
 503         }
 504
 505         /**
 506          * @param string $table
 507          * @param array $uniqueIndexes
 508          * @param array $rows
 509          * @param string $fname
 510          * @return ResultWrapper
 511          */
 512         public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
 513                 return $this->nativeReplace( $table, $rows, $fname );
 514         }
 515
 516         protected function isInsertSelectSafe( array $insertOptions, array $selectOptions ) {
 517                 $row = $this->getReplicationSafetyInfo();
 518                 // For row-based-replication, the resulting changes will be relayed, not the query
 519                 if ( $row->binlog_format === 'ROW' ) {
 520                         return true;
 521                 }
 522                 // LIMIT requires ORDER BY on a unique key or it is non-deterministic
 523                 if ( isset( $selectOptions['LIMIT'] ) ) {
 524                         return false;
 525                 }
 526                 // In MySQL, an INSERT SELECT is only replication safe with row-based
 527                 // replication or if innodb_autoinc_lock_mode is 0. When those
 528                 // conditions aren't met, use non-native mode.
 529                 // While we could try to determine if the insert is safe anyway by
 530                 // checking if the target table has an auto-increment column that
 531                 // isn't set in $varMap, that seems unlikely to be worth the extra
 532                 // complexity.
 533                 return (
 534                         in_array( 'NO_AUTO_COLUMNS', $insertOptions ) ||
 535                         (int)$row->innodb_autoinc_lock_mode === 0
 536                 );
 537         }
 538
 539         /**
 540          * @return stdClass Process cached row
 541          */
 542         protected function getReplicationSafetyInfo() {
 543                 if ( $this->replicationInfoRow === null ) {
 544                         $this->replicationInfoRow = $this->selectRow(
 545                                 false,
 546                                 [
 547                                         'innodb_autoinc_lock_mode' => '@@innodb_autoinc_lock_mode',
 548                                         'binlog_format' => '@@binlog_format',
 549                                 ],
 550                                 [],
 551                                 __METHOD__
 552                         );
 553                 }
 554
 555                 return $this->replicationInfoRow;
 556         }
 557
 558         /**
 559          * Estimate rows in dataset
 560          * Returns estimated count, based on EXPLAIN output
 561          * Takes same arguments as Database::select()
 562          *
 563          * @param string|array $table
 564          * @param string|array $var
 565          * @param string|array $conds
 566          * @param string $fname
 567          * @param string|array $options
 568          * @param array $join_conds
 569          * @return bool|int
 570          */
 571         public function estimateRowCount( $table, $var = '*', $conds = '',
 572                 $fname = __METHOD__, $options = [], $join_conds = []
 573         ) {
 574                 $conds = $this->normalizeConditions( $conds, $fname );
 575                 $column = $this->extractSingleFieldFromList( $var );
 576                 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
 577                         $conds[] = "$column IS NOT NULL";
 578                 }
 579
 580                 $options['EXPLAIN'] = true;
 581                 $res = $this->select( $table, $var, $conds, $fname, $options, $join_conds );
 582                 if ( $res === false ) {
 583                         return false;
 584                 }
 585                 if ( !$this->numRows( $res ) ) {
 586                         return 0;
 587                 }
 588
 589                 $rows = 1;
 590                 foreach ( $res as $plan ) {
 591                         $rows *= $plan->rows > 0 ? $plan->rows : 1; // avoid resetting to zero
 592                 }
 593
 594                 return (int)$rows;
 595         }
 596
 597         public function tableExists( $table, $fname = __METHOD__ ) {
 598                 // Split database and table into proper variables as Database::tableName() returns
 599                 // shared tables prefixed with their database, which do not work in SHOW TABLES statements
 600                 list( $database, , $prefix, $table ) = $this->qualifiedTableComponents( $table );
 601                 $tableName = "{$prefix}{$table}";
 602
 603                 if ( isset( $this->sessionTempTables[$tableName] ) ) {
 604                         return true; // already known to exist and won't show in SHOW TABLES anyway
 605                 }
 606
 607                 // We can't use buildLike() here, because it specifies an escape character
 608                 // other than the backslash, which is the only one supported by SHOW TABLES
 609                 $encLike = $this->escapeLikeInternal( $tableName, '\\' );
 610
 611                 // If the database has been specified (such as for shared tables), use "FROM"
 612                 if ( $database !== '' ) {
 613                         $encDatabase = $this->addIdentifierQuotes( $database );
 614                         $query = "SHOW TABLES FROM $encDatabase LIKE '$encLike'";
 615                 } else {
 616                         $query = "SHOW TABLES LIKE '$encLike'";
 617                 }
 618
 619                 return $this->query( $query, $fname )->numRows() > 0;
 620         }
 621
 622         /**
 623          * @param string $table
 624          * @param string $field
 625          * @return bool|MySQLField
 626          */
 627         public function fieldInfo( $table, $field ) {
 628                 $table = $this->tableName( $table );
 629                 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__, true );
 630                 if ( !$res ) {
 631                         return false;
 632                 }
 633                 $n = $this->mysqlNumFields( $res->result );
 634                 for ( $i = 0; $i < $n; $i++ ) {
 635                         $meta = $this->mysqlFetchField( $res->result, $i );
 636                         if ( $field == $meta->name ) {
 637                                 return new MySQLField( $meta );
 638                         }
 639                 }
 640
 641                 return false;
 642         }
 643
 644         /**
 645          * Get column information from a result
 646          *
 647          * @param resource $res Raw result
 648          * @param int $n
 649          * @return stdClass
 650          */
 651         abstract protected function mysqlFetchField( $res, $n );
 652
 653         /**
 654          * Get information about an index into an object
 655          * Returns false if the index does not exist
 656          *
 657          * @param string $table
 658          * @param string $index
 659          * @param string $fname
 660          * @return bool|array|null False or null on failure
 661          */
 662         public function indexInfo( $table, $index, $fname = __METHOD__ ) {
 663                 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
 664                 # SHOW INDEX should work for 3.x and up:
 665                 # https://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
 666                 $table = $this->tableName( $table );
 667                 $index = $this->indexName( $index );
 668
 669                 $sql = 'SHOW INDEX FROM ' . $table;
 670                 $res = $this->query( $sql, $fname );
 671
 672                 if ( !$res ) {
 673                         return null;
 674                 }
 675
 676                 $result = [];
 677
 678                 foreach ( $res as $row ) {
 679                         if ( $row->Key_name == $index ) {
 680                                 $result[] = $row;
 681                         }
 682                 }
 683
 684                 return $result ?: false;
 685         }
 686
 687         /**
 688          * @param string $s
 689          * @return string
 690          */
 691         public function strencode( $s ) {
 692                 return $this->mysqlRealEscapeString( $s );
 693         }
 694
 695         /**
 696          * @param string $s
 697          * @return mixed
 698          */
 699         abstract protected function mysqlRealEscapeString( $s );
 700
 701         public function addQuotes( $s ) {
 702                 if ( is_bool( $s ) ) {
 703                         // Parent would transform to int, which does not play nice with MySQL type juggling.
 704                         // When searching for an int in a string column, the strings are cast to int, which
 705                         // means false would match any string not starting with a number.
 706                         $s = (string)(int)$s;
 707                 }
 708                 return parent::addQuotes( $s );
 709         }
 710
 711         /**
 712          * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
 713          *
 714          * @param string $s
 715          * @return string
 716          */
 717         public function addIdentifierQuotes( $s ) {
 718                 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
 719                 // Remove NUL bytes and escape backticks by doubling
 720                 return '`' . str_replace( [ "\0", '`' ], [ '', '``' ], $s ) . '`';
 721         }
 722
 723         /**
 724          * @param string $name
 725          * @return bool
 726          */
 727         public function isQuotedIdentifier( $name ) {
 728                 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
 729         }
 730
 731         public function getLag() {
 732                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 733                         return $this->getLagFromPtHeartbeat();
 734                 } else {
 735                         return $this->getLagFromSlaveStatus();
 736                 }
 737         }
 738
 739         /**
 740          * @return string
 741          */
 742         protected function getLagDetectionMethod() {
 743                 return $this->lagDetectionMethod;
 744         }
 745
 746         /**
 747          * @return bool|int
 748          */
 749         protected function getLagFromSlaveStatus() {
 750                 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
 751                 $row = $res ? $res->fetchObject() : false;
 752                 // If the server is not replicating, there will be no row
 753                 if ( $row && strval( $row->Seconds_Behind_Master ) !== '' ) {
 754                         return intval( $row->Seconds_Behind_Master );
 755                 }
 756
 757                 return false;
 758         }
 759
 760         /**
 761          * @return bool|float
 762          */
 763         protected function getLagFromPtHeartbeat() {
 764                 $options = $this->lagDetectionOptions;
 765
 766                 if ( $this->trxLevel ) {
 767                         // Avoid returning higher and higher lag value due to snapshot age
 768                         // given that the isolation level will typically be REPEATABLE-READ
 769                         $this->queryLogger->warning(
 770                                 "Using cached lag value for {db_server} due to active transaction",
 771                                 $this->getLogContext( [ 'method' => __METHOD__ ] )
 772                         );
 773
 774                         return $this->getTransactionLagStatus()['lag'];
 775                 }
 776
 777                 if ( isset( $options['conds'] ) ) {
 778                         // Best method for multi-DC setups: use logical channel names
 779                         $data = $this->getHeartbeatData( $options['conds'] );
 780                 } else {
 781                         // Standard method: use master server ID (works with stock pt-heartbeat)
 782                         $masterInfo = $this->getMasterServerInfo();
 783                         if ( !$masterInfo ) {
 784                                 $this->queryLogger->error(
 785                                         "Unable to query master of {db_server} for server ID",
 786                                         $this->getLogContext( [
 787                                                 'method' => __METHOD__
 788                                         ] )
 789                                 );
 790
 791                                 return false; // could not get master server ID
 792                         }
 793
 794                         $conds = [ 'server_id' => intval( $masterInfo['serverId'] ) ];
 795                         $data = $this->getHeartbeatData( $conds );
 796                 }
 797
 798                 list( $time, $nowUnix ) = $data;
 799                 if ( $time !== null ) {
 800                         // @time is in ISO format like "2015-09-25T16:48:10.000510"
 801                         $dateTime = new DateTime( $time, new DateTimeZone( 'UTC' ) );
 802                         $timeUnix = (int)$dateTime->format( 'U' ) + $dateTime->format( 'u' ) / 1e6;
 803
 804                         return max( $nowUnix - $timeUnix, 0.0 );
 805                 }
 806
 807                 $this->queryLogger->error(
 808                         "Unable to find pt-heartbeat row for {db_server}",
 809                         $this->getLogContext( [
 810                                 'method' => __METHOD__
 811                         ] )
 812                 );
 813
 814                 return false;
 815         }
 816
 817         protected function getMasterServerInfo() {
 818                 $cache = $this->srvCache;
 819                 $key = $cache->makeGlobalKey(
 820                         'mysql',
 821                         'master-info',
 822                         // Using one key for all cluster replica DBs is preferable
 823                         $this->getLBInfo( 'clusterMasterHost' ) ?: $this->getServer()
 824                 );
 825
 826                 return $cache->getWithSetCallback(
 827                         $key,
 828                         $cache::TTL_INDEFINITE,
 829                         function () use ( $cache, $key ) {
 830                                 // Get and leave a lock key in place for a short period
 831                                 if ( !$cache->lock( $key, 0, 10 ) ) {
 832                                         return false; // avoid master connection spike slams
 833                                 }
 834
 835                                 $conn = $this->getLazyMasterHandle();
 836                                 if ( !$conn ) {
 837                                         return false; // something is misconfigured
 838                                 }
 839
 840                                 // Connect to and query the master; catch errors to avoid outages
 841                                 try {
 842                                         $res = $conn->query( 'SELECT @@server_id AS id', __METHOD__ );
 843                                         $row = $res ? $res->fetchObject() : false;
 844                                         $id = $row ? (int)$row->id : 0;
 845                                 } catch ( DBError $e ) {
 846                                         $id = 0;
 847                                 }
 848
 849                                 // Cache the ID if it was retrieved
 850                                 return $id ? [ 'serverId' => $id, 'asOf' => time() ] : false;
 851                         }
 852                 );
 853         }
 854
 855         /**
 856          * @param array $conds WHERE clause conditions to find a row
 857          * @return array (heartbeat `ts` column value or null, UNIX timestamp) for the newest beat
 858          * @see https://www.percona.com/doc/percona-toolkit/2.1/pt-heartbeat.html
 859          */
 860         protected function getHeartbeatData( array $conds ) {
 861                 // Query time and trip time are not counted
 862                 $nowUnix = microtime( true );
 863                 // Do not bother starting implicit transactions here
 864                 $this->clearFlag( self::DBO_TRX, self::REMEMBER_PRIOR );
 865                 try {
 866                         $whereSQL = $this->makeList( $conds, self::LIST_AND );
 867                         // Use ORDER BY for channel based queries since that field might not be UNIQUE.
 868                         // Note: this would use "TIMESTAMPDIFF(MICROSECOND,ts,UTC_TIMESTAMP(6))" but the
 869                         // percision field is not supported in MySQL <= 5.5.
 870                         $res = $this->query(
 871                                 "SELECT ts FROM heartbeat.heartbeat WHERE $whereSQL ORDER BY ts DESC LIMIT 1",
 872                                 __METHOD__
 873                         );
 874                         $row = $res ? $res->fetchObject() : false;
 875                 } finally {
 876                         $this->restoreFlags();
 877                 }
 878
 879                 return [ $row ? $row->ts : null, $nowUnix ];
 880         }
 881
 882         protected function getApproximateLagStatus() {
 883                 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
 884                         // Disable caching since this is fast enough and we don't wan't
 885                         // to be *too* pessimistic by having both the cache TTL and the
 886                         // pt-heartbeat interval count as lag in getSessionLagStatus()
 887                         return parent::getApproximateLagStatus();
 888                 }
 889
 890                 $key = $this->srvCache->makeGlobalKey( 'mysql-lag', $this->getServer() );
 891                 $approxLag = $this->srvCache->get( $key );
 892                 if ( !$approxLag ) {
 893                         $approxLag = parent::getApproximateLagStatus();
 894                         $this->srvCache->set( $key, $approxLag, 1 );
 895                 }
 896
 897                 return $approxLag;
 898         }
 899
 900         public function masterPosWait( DBMasterPos $pos, $timeout ) {
 901                 if ( !( $pos instanceof MySQLMasterPos ) ) {
 902                         throw new InvalidArgumentException( "Position not an instance of MySQLMasterPos" );
 903                 }
 904
 905                 if ( $this->getLBInfo( 'is static' ) === true ) {
 906                         return 0; // this is a copy of a read-only dataset with no master DB
 907                 } elseif ( $this->lastKnownReplicaPos && $this->lastKnownReplicaPos->hasReached( $pos ) ) {
 908                         return 0; // already reached this point for sure
 909                 }
 910
 911                 // Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
 912                 if ( $pos->getGTIDs() ) {
 913                         // Ignore GTIDs from domains exclusive to the master DB (presumably inactive)
 914                         $rpos = $this->getReplicaPos();
 915                         $gtidsWait = $rpos ? MySQLMasterPos::getCommonDomainGTIDs( $pos, $rpos ) : [];
 916                         if ( !$gtidsWait ) {
 917                                 $this->queryLogger->error(
 918                                         "No GTIDs with the same domain between master ($pos) and replica ($rpos)",
 919                                         $this->getLogContext( [
 920                                                 'method' => __METHOD__,
 921                                         ] )
 922                                 );
 923
 924                                 return -1; // $pos is from the wrong cluster?
 925                         }
 926                         // Wait on the GTID set (MariaDB only)
 927                         $gtidArg = $this->addQuotes( implode( ',', $gtidsWait ) );
 928                         if ( strpos( $gtidArg, ':' ) !== false ) {
 929                                 // MySQL GTIDs, e.g "source_id:transaction_id"
 930                                 $res = $this->doQuery( "SELECT WAIT_FOR_EXECUTED_GTID_SET($gtidArg, $timeout)" );
 931                         } else {
 932                                 // MariaDB GTIDs, e.g."domain:server:sequence"
 933                                 $res = $this->doQuery( "SELECT MASTER_GTID_WAIT($gtidArg, $timeout)" );
 934                         }
 935                 } else {
 936                         // Wait on the binlog coordinates
 937                         $encFile = $this->addQuotes( $pos->getLogFile() );
 938                         $encPos = intval( $pos->getLogPosition()[$pos::CORD_EVENT] );
 939                         $res = $this->doQuery( "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)" );
 940                 }
 941
 942                 $row = $res ? $this->fetchRow( $res ) : false;
 943                 if ( !$row ) {
 944                         throw new DBExpectedError( $this, "Replication wait failed: {$this->lastError()}" );
 945                 }
 946
 947                 // Result can be NULL (error), -1 (timeout), or 0+ per the MySQL manual
 948                 $status = ( $row[0] !== null ) ? intval( $row[0] ) : null;
 949                 if ( $status === null ) {
 950                         if ( !$pos->getGTIDs() ) {
 951                                 // T126436: jobs programmed to wait on master positions might be referencing
 952                                 // binlogs with an old master hostname; this makes MASTER_POS_WAIT() return null.
 953                                 // Try to detect this case and treat the replica DB as having reached the given
 954                                 // position (any master switchover already requires that the new master be caught
 955                                 // up before the switch).
 956                                 $replicationPos = $this->getReplicaPos();
 957                                 if ( $replicationPos && !$replicationPos->channelsMatch( $pos ) ) {
 958                                         $this->lastKnownReplicaPos = $replicationPos;
 959                                         $status = 0;
 960                                 }
 961                         }
 962                 } elseif ( $status >= 0 ) {
 963                         // Remember that this position was reached to save queries next time
 964                         $this->lastKnownReplicaPos = $pos;
 965                 }
 966
 967                 return $status;
 968         }
 969
 970         /**
 971          * Get the position of the master from SHOW SLAVE STATUS
 972          *
 973          * @return MySQLMasterPos|bool
 974          */
 975         public function getReplicaPos() {
 976                 $now = microtime( true ); // as-of-time *before* fetching GTID variables
 977
 978                 if ( $this->useGTIDs() ) {
 979                         // Try to use GTIDs, fallbacking to binlog positions if not possible
 980                         $data = $this->getServerGTIDs( __METHOD__ );
 981                         // Use gtid_current_pos for MariaDB and gtid_executed for MySQL
 982                         foreach ( [ 'gtid_current_pos', 'gtid_executed' ] as $name ) {
 983                                 if ( isset( $data[$name] ) && strlen( $data[$name] ) ) {
 984                                         return new MySQLMasterPos( $data[$name], $now );
 985                                 }
 986                         }
 987                 }
 988
 989                 $data = $this->getServerRoleStatus( 'SLAVE', __METHOD__ );
 990                 if ( $data && strlen( $data['Relay_Master_Log_File'] ) ) {
 991                         return new MySQLMasterPos(
 992                                 "{$data['Relay_Master_Log_File']}/{$data['Exec_Master_Log_Pos']}",
 993                                 $now
 994                         );
 995                 }
 996
 997                 return false;
 998         }
 999
1000         /**
1001          * Get the position of the master from SHOW MASTER STATUS
1002          *
1003          * @return MySQLMasterPos|bool
1004          */
1005         public function getMasterPos() {
1006                 $now = microtime( true ); // as-of-time *before* fetching GTID variables
1007
1008                 $pos = false;
1009                 if ( $this->useGTIDs() ) {
1010                         // Try to use GTIDs, fallbacking to binlog positions if not possible
1011                         $data = $this->getServerGTIDs( __METHOD__ );
1012                         // Use gtid_current_pos for MariaDB and gtid_executed for MySQL
1013                         foreach ( [ 'gtid_current_pos', 'gtid_executed' ] as $name ) {
1014                                 if ( isset( $data[$name] ) && strlen( $data[$name] ) ) {
1015                                         $pos = new MySQLMasterPos( $data[$name], $now );
1016                                         break;
1017                                 }
1018                         }
1019                         // Filter domains that are inactive or not relevant to the session
1020                         if ( $pos ) {
1021                                 $pos->setActiveOriginServerId( $this->getServerId() );
1022                                 $pos->setActiveOriginServerUUID( $this->getServerUUID() );
1023                                 if ( isset( $data['gtid_domain_id'] ) ) {
1024                                         $pos->setActiveDomain( $data['gtid_domain_id'] );
1025                                 }
1026                         }
1027                 }
1028
1029                 if ( !$pos ) {
1030                         $data = $this->getServerRoleStatus( 'MASTER', __METHOD__ );
1031                         if ( $data && strlen( $data['File'] ) ) {
1032                                 $pos = new MySQLMasterPos( "{$data['File']}/{$data['Position']}", $now );
1033                         }
1034                 }
1035
1036                 return $pos;
1037         }
1038
1039         /**
1040          * @return int
1041          * @throws DBQueryError If the variable doesn't exist for some reason
1042          */
1043         protected function getServerId() {
1044                 return $this->srvCache->getWithSetCallback(
1045                         $this->srvCache->makeGlobalKey( 'mysql-server-id', $this->getServer() ),
1046                         self::SERVER_ID_CACHE_TTL,
1047                         function () {
1048                                 $res = $this->query( "SELECT @@server_id AS id", __METHOD__ );
1049                                 return intval( $this->fetchObject( $res )->id );
1050                         }
1051                 );
1052         }
1053
1054         /**
1055          * @return string|null
1056          */
1057         protected function getServerUUID() {
1058                 return $this->srvCache->getWithSetCallback(
1059                         $this->srvCache->makeGlobalKey( 'mysql-server-uuid', $this->getServer() ),
1060                         self::SERVER_ID_CACHE_TTL,
1061                         function () {
1062                                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'server_uuid'" );
1063                                 $row = $this->fetchObject( $res );
1064
1065                                 return $row ? $row->Value : null;
1066                         }
1067                 );
1068         }
1069
1070         /**
1071          * @param string $fname
1072          * @return string[]
1073          */
1074         protected function getServerGTIDs( $fname = __METHOD__ ) {
1075                 $map = [];
1076                 // Get global-only variables like gtid_executed
1077                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_%'", $fname );
1078                 foreach ( $res as $row ) {
1079                         $map[$row->Variable_name] = $row->Value;
1080                 }
1081                 // Get session-specific (e.g. gtid_domain_id since that is were writes will log)
1082                 $res = $this->query( "SHOW SESSION VARIABLES LIKE 'gtid_%'", $fname );
1083                 foreach ( $res as $row ) {
1084                         $map[$row->Variable_name] = $row->Value;
1085                 }
1086
1087                 return $map;
1088         }
1089
1090         /**
1091          * @param string $role One of "MASTER"/"SLAVE"
1092          * @param string $fname
1093          * @return string[] Latest available server status row
1094          */
1095         protected function getServerRoleStatus( $role, $fname = __METHOD__ ) {
1096                 return $this->query( "SHOW $role STATUS", $fname )->fetchRow() ?: [];
1097         }
1098
1099         public function serverIsReadOnly() {
1100                 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'read_only'", __METHOD__ );
1101                 $row = $this->fetchObject( $res );
1102
1103                 return $row ? ( strtolower( $row->Value ) === 'on' ) : false;
1104         }
1105
1106         /**
1107          * @param string $index
1108          * @return string
1109          */
1110         function useIndexClause( $index ) {
1111                 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
1112         }
1113
1114         /**
1115          * @param string $index
1116          * @return string
1117          */
1118         function ignoreIndexClause( $index ) {
1119                 return "IGNORE INDEX (" . $this->indexName( $index ) . ")";
1120         }
1121
1122         /**
1123          * @return string
1124          */
1125         function lowPriorityOption() {
1126                 return 'LOW_PRIORITY';
1127         }
1128
1129         /**
1130          * @return string
1131          */
1132         public function getSoftwareLink() {
1133                 // MariaDB includes its name in its version string; this is how MariaDB's version of
1134                 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
1135                 // in libmysql/libmysql.c).
1136                 $version = $this->getServerVersion();
1137                 if ( strpos( $version, 'MariaDB' ) !== false || strpos( $version, '-maria-' ) !== false ) {
1138                         return '[{{int:version-db-mariadb-url}} MariaDB]';
1139                 }
1140
1141                 // Percona Server's version suffix is not very distinctive, and @@version_comment
1142                 // doesn't give the necessary info for source builds, so assume the server is MySQL.
1143                 // (Even Percona's version of mysql doesn't try to make the distinction.)
1144                 return '[{{int:version-db-mysql-url}} MySQL]';
1145         }
1146
1147         /**
1148          * @return string
1149          */
1150         public function getServerVersion() {
1151                 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
1152                 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
1153                 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
1154                 if ( $this->serverVersion === null ) {
1155                         $this->serverVersion = $this->selectField( '', 'VERSION()', '', __METHOD__ );
1156                 }
1157                 return $this->serverVersion;
1158         }
1159
1160         /**
1161          * @param array $options
1162          */
1163         public function setSessionOptions( array $options ) {
1164                 if ( isset( $options['connTimeout'] ) ) {
1165                         $timeout = (int)$options['connTimeout'];
1166                         $this->query( "SET net_read_timeout=$timeout" );
1167                         $this->query( "SET net_write_timeout=$timeout" );
1168                 }
1169         }
1170
1171         /**
1172          * @param string &$sql
1173          * @param string &$newLine
1174          * @return bool
1175          */
1176         public function streamStatementEnd( &$sql, &$newLine ) {
1177                 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
1178                         preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
1179                         $this->delimiter = $m[1];
1180                         $newLine = '';
1181                 }
1182
1183                 return parent::streamStatementEnd( $sql, $newLine );
1184         }
1185
1186         /**
1187          * Check to see if a named lock is available. This is non-blocking.
1188          *
1189          * @param string $lockName Name of lock to poll
1190          * @param string $method Name of method calling us
1191          * @return bool
1192          * @since 1.20
1193          */
1194         public function lockIsFree( $lockName, $method ) {
1195                 if ( !parent::lockIsFree( $lockName, $method ) ) {
1196                         return false; // already held
1197                 }
1198
1199                 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1200                 $result = $this->query( "SELECT IS_FREE_LOCK($encName) AS lockstatus", $method );
1201                 $row = $this->fetchObject( $result );
1202
1203                 return ( $row->lockstatus == 1 );
1204         }
1205
1206         /**
1207          * @param string $lockName
1208          * @param string $method
1209          * @param int $timeout
1210          * @return bool
1211          */
1212         public function lock( $lockName, $method, $timeout = 5 ) {
1213                 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1214                 $result = $this->query( "SELECT GET_LOCK($encName, $timeout) AS lockstatus", $method );
1215                 $row = $this->fetchObject( $result );
1216
1217                 if ( $row->lockstatus == 1 ) {
1218                         parent::lock( $lockName, $method, $timeout ); // record
1219                         return true;
1220                 }
1221
1222                 $this->queryLogger->info( __METHOD__ . " failed to acquire lock '{lockname}'",
1223                         [ 'lockname' => $lockName ] );
1224
1225                 return false;
1226         }
1227
1228         /**
1229          * FROM MYSQL DOCS:
1230          * https://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
1231          * @param string $lockName
1232          * @param string $method
1233          * @return bool
1234          */
1235         public function unlock( $lockName, $method ) {
1236                 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1237                 $result = $this->query( "SELECT RELEASE_LOCK($encName) as lockstatus", $method );
1238                 $row = $this->fetchObject( $result );
1239
1240                 if ( $row->lockstatus == 1 ) {
1241                         parent::unlock( $lockName, $method ); // record
1242                         return true;
1243                 }
1244
1245                 $this->queryLogger->warning( __METHOD__ . " failed to release lock '$lockName'\n" );
1246
1247                 return false;
1248         }
1249
1250         private function makeLockName( $lockName ) {
1251                 // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1252                 // Newer version enforce a 64 char length limit.
1253                 return ( strlen( $lockName ) > 64 ) ? sha1( $lockName ) : $lockName;
1254         }
1255
1256         public function namedLocksEnqueue() {
1257                 return true;
1258         }
1259
1260         public function tableLocksHaveTransactionScope() {
1261                 return false; // tied to TCP connection
1262         }
1263
1264         protected function doLockTables( array $read, array $write, $method ) {
1265                 $items = [];
1266                 foreach ( $write as $table ) {
1267                         $items[] = $this->tableName( $table ) . ' WRITE';
1268                 }
1269                 foreach ( $read as $table ) {
1270                         $items[] = $this->tableName( $table ) . ' READ';
1271                 }
1272
1273                 $sql = "LOCK TABLES " . implode( ',', $items );
1274                 $this->query( $sql, $method );
1275
1276                 return true;
1277         }
1278
1279         protected function doUnlockTables( $method ) {
1280                 $this->query( "UNLOCK TABLES", $method );
1281
1282                 return true;
1283         }
1284
1285         /**
1286          * @param bool $value
1287          */
1288         public function setBigSelects( $value = true ) {
1289                 if ( $value === 'default' ) {
1290                         if ( $this->defaultBigSelects === null ) {
1291                                 # Function hasn't been called before so it must already be set to the default
1292                                 return;
1293                         } else {
1294                                 $value = $this->defaultBigSelects;
1295                         }
1296                 } elseif ( $this->defaultBigSelects === null ) {
1297                         $this->defaultBigSelects =
1298                                 (bool)$this->selectField( false, '@@sql_big_selects', '', __METHOD__ );
1299                 }
1300                 $encValue = $value ? '1' : '0';
1301                 $this->query( "SET sql_big_selects=$encValue", __METHOD__ );
1302         }
1303
1304         /**
1305          * DELETE where the condition is a join. MySql uses multi-table deletes.
1306          * @param string $delTable
1307          * @param string $joinTable
1308          * @param string $delVar
1309          * @param string $joinVar
1310          * @param array|string $conds
1311          * @param bool|string $fname
1312          * @throws DBUnexpectedError
1313          * @return bool|ResultWrapper
1314          */
1315         public function deleteJoin(
1316                 $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__
1317         ) {
1318                 if ( !$conds ) {
1319                         throw new DBUnexpectedError( $this, __METHOD__ . ' called with empty $conds' );
1320                 }
1321
1322                 $delTable = $this->tableName( $delTable );
1323                 $joinTable = $this->tableName( $joinTable );
1324                 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1325
1326                 if ( $conds != '*' ) {
1327                         $sql .= ' AND ' . $this->makeList( $conds, self::LIST_AND );
1328                 }
1329
1330                 return $this->query( $sql, $fname );
1331         }
1332
1333         /**
1334          * @param string $table
1335          * @param array $rows
1336          * @param array $uniqueIndexes
1337          * @param array $set
1338          * @param string $fname
1339          * @return bool
1340          */
1341         public function upsert( $table, array $rows, array $uniqueIndexes,
1342                 array $set, $fname = __METHOD__
1343         ) {
1344                 if ( !count( $rows ) ) {
1345                         return true; // nothing to do
1346                 }
1347
1348                 if ( !is_array( reset( $rows ) ) ) {
1349                         $rows = [ $rows ];
1350                 }
1351
1352                 $table = $this->tableName( $table );
1353                 $columns = array_keys( $rows[0] );
1354
1355                 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
1356                 $rowTuples = [];
1357                 foreach ( $rows as $row ) {
1358                         $rowTuples[] = '(' . $this->makeList( $row ) . ')';
1359                 }
1360                 $sql .= implode( ',', $rowTuples );
1361                 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, self::LIST_SET );
1362
1363                 return (bool)$this->query( $sql, $fname );
1364         }
1365
1366         /**
1367          * Determines how long the server has been up
1368          *
1369          * @return int
1370          */
1371         public function getServerUptime() {
1372                 $vars = $this->getMysqlStatus( 'Uptime' );
1373
1374                 return (int)$vars['Uptime'];
1375         }
1376
1377         /**
1378          * Determines if the last failure was due to a deadlock
1379          *
1380          * @return bool
1381          */
1382         public function wasDeadlock() {
1383                 return $this->lastErrno() == 1213;
1384         }
1385
1386         /**
1387          * Determines if the last failure was due to a lock timeout
1388          *
1389          * @return bool
1390          */
1391         public function wasLockTimeout() {
1392                 return $this->lastErrno() == 1205;
1393         }
1394
1395         /**
1396          * Determines if the last failure was due to the database being read-only.
1397          *
1398          * @return bool
1399          */
1400         public function wasReadOnlyError() {
1401                 return $this->lastErrno() == 1223 ||
1402                         ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1403         }
1404
1405         public function wasConnectionError( $errno ) {
1406                 return $errno == 2013 || $errno == 2006;
1407         }
1408
1409         /**
1410          * @param string $oldName
1411          * @param string $newName
1412          * @param bool $temporary
1413          * @param string $fname
1414          * @return bool
1415          */
1416         public function duplicateTableStructure(
1417                 $oldName, $newName, $temporary = false, $fname = __METHOD__
1418         ) {
1419                 $tmp = $temporary ? 'TEMPORARY ' : '';
1420                 $newName = $this->addIdentifierQuotes( $newName );
1421                 $oldName = $this->addIdentifierQuotes( $oldName );
1422                 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1423
1424                 return $this->query( $query, $fname );
1425         }
1426
1427         /**
1428          * List all tables on the database
1429          *
1430          * @param string $prefix Only show tables with this prefix, e.g. mw_
1431          * @param string $fname Calling function name
1432          * @return array
1433          */
1434         public function listTables( $prefix = null, $fname = __METHOD__ ) {
1435                 $result = $this->query( "SHOW TABLES", $fname );
1436
1437                 $endArray = [];
1438
1439                 foreach ( $result as $table ) {
1440                         $vars = get_object_vars( $table );
1441                         $table = array_pop( $vars );
1442
1443                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1444                                 $endArray[] = $table;
1445                         }
1446                 }
1447
1448                 return $endArray;
1449         }
1450
1451         /**
1452          * @param string $tableName
1453          * @param string $fName
1454          * @return bool|ResultWrapper
1455          */
1456         public function dropTable( $tableName, $fName = __METHOD__ ) {
1457                 if ( !$this->tableExists( $tableName, $fName ) ) {
1458                         return false;
1459                 }
1460
1461                 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1462         }
1463
1464         /**
1465          * Get status information from SHOW STATUS in an associative array
1466          *
1467          * @param string $which
1468          * @return array
1469          */
1470         private function getMysqlStatus( $which = "%" ) {
1471                 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
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 $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->dbName;
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 $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         /**
1534          * @param string $field Field or column to cast
1535          * @return string
1536          */
1537         public function buildIntegerCast( $field ) {
1538                 return 'CAST( ' . $field . ' AS SIGNED )';
1539         }
1540
1541         /*
1542          * @return bool Whether GTID support is used (mockable for testing)
1543          */
1544         protected function useGTIDs() {
1545                 return $this->useGTIDs;
1546         }
1547 }
1548
1549 class_alias( DatabaseMysqlBase::class, 'DatabaseMysqlBase' );