includes/libs/rdbms/database/DatabasePostgres.php

   1 <?php
   2 /**
   3  * This is the Postgres 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 use Wikimedia\WaitConditionLoop;
  24
  25 /**
  26  * @ingroup Database
  27  */
  28 class DatabasePostgres extends Database {
  29         /** @var int|bool */
  30         protected $port;
  31
  32         /** @var resource */
  33         protected $mLastResult = null;
  34         /** @var int The number of rows affected as an integer */
  35         protected $mAffectedRows = null;
  36
  37         /** @var int */
  38         private $mInsertId = null;
  39         /** @var float|string */
  40         private $numericVersion = null;
  41         /** @var string Connect string to open a PostgreSQL connection */
  42         private $connectString;
  43         /** @var string */
  44         private $mCoreSchema;
  45
  46         public function __construct( array $params ) {
  47                 $this->port = isset( $params['port'] ) ? $params['port'] : false;
  48                 parent::__construct( $params );
  49         }
  50
  51         public function getType() {
  52                 return 'postgres';
  53         }
  54
  55         public function implicitGroupby() {
  56                 return false;
  57         }
  58
  59         public function implicitOrderby() {
  60                 return false;
  61         }
  62
  63         public function hasConstraint( $name ) {
  64                 $conn = $this->getBindingHandle();
  65
  66                 $sql = "SELECT 1 FROM pg_catalog.pg_constraint c, pg_catalog.pg_namespace n " .
  67                         "WHERE c.connamespace = n.oid AND conname = '" .
  68                         pg_escape_string( $conn, $name ) . "' AND n.nspname = '" .
  69                         pg_escape_string( $conn, $this->getCoreSchema() ) . "'";
  70                 $res = $this->doQuery( $sql );
  71
  72                 return $this->numRows( $res );
  73         }
  74
  75         public function open( $server, $user, $password, $dbName ) {
  76                 # Test for Postgres support, to avoid suppressed fatal error
  77                 if ( !function_exists( 'pg_connect' ) ) {
  78                         throw new DBConnectionError(
  79                                 $this,
  80                                 "Postgres functions missing, have you compiled PHP with the --with-pgsql\n" .
  81                                 "option? (Note: if you recently installed PHP, you may need to restart your\n" .
  82                                 "webserver and database)\n"
  83                         );
  84                 }
  85
  86                 $this->mServer = $server;
  87                 $this->mUser = $user;
  88                 $this->mPassword = $password;
  89                 $this->mDBname = $dbName;
  90
  91                 $connectVars = [
  92                         'dbname' => $dbName,
  93                         'user' => $user,
  94                         'password' => $password
  95                 ];
  96                 if ( $server != false && $server != '' ) {
  97                         $connectVars['host'] = $server;
  98                 }
  99                 if ( (int)$this->port > 0 ) {
 100                         $connectVars['port'] = (int)$this->port;
 101                 }
 102                 if ( $this->mFlags & self::DBO_SSL ) {
 103                         $connectVars['sslmode'] = 1;
 104                 }
 105
 106                 $this->connectString = $this->makeConnectionString( $connectVars );
 107                 $this->close();
 108                 $this->installErrorHandler();
 109
 110                 try {
 111                         // Use new connections to let LoadBalancer/LBFactory handle reuse
 112                         $this->mConn = pg_connect( $this->connectString, PGSQL_CONNECT_FORCE_NEW );
 113                 } catch ( Exception $ex ) {
 114                         $this->restoreErrorHandler();
 115                         throw $ex;
 116                 }
 117
 118                 $phpError = $this->restoreErrorHandler();
 119
 120                 if ( !$this->mConn ) {
 121                         $this->queryLogger->debug(
 122                                 "DB connection error\n" .
 123                                 "Server: $server, Database: $dbName, User: $user, Password: " .
 124                                 substr( $password, 0, 3 ) . "...\n"
 125                         );
 126                         $this->queryLogger->debug( $this->lastError() . "\n" );
 127                         throw new DBConnectionError( $this, str_replace( "\n", ' ', $phpError ) );
 128                 }
 129
 130                 $this->mOpened = true;
 131
 132                 # If called from the command-line (e.g. importDump), only show errors
 133                 if ( $this->cliMode ) {
 134                         $this->doQuery( "SET client_min_messages = 'ERROR'" );
 135                 }
 136
 137                 $this->query( "SET client_encoding='UTF8'", __METHOD__ );
 138                 $this->query( "SET datestyle = 'ISO, YMD'", __METHOD__ );
 139                 $this->query( "SET timezone = 'GMT'", __METHOD__ );
 140                 $this->query( "SET standard_conforming_strings = on", __METHOD__ );
 141                 if ( $this->getServerVersion() >= 9.0 ) {
 142                         $this->query( "SET bytea_output = 'escape'", __METHOD__ ); // PHP bug 53127
 143                 }
 144
 145                 $this->determineCoreSchema( $this->mSchema );
 146                 // The schema to be used is now in the search path; no need for explicit qualification
 147                 $this->mSchema = '';
 148
 149                 return $this->mConn;
 150         }
 151
 152         /**
 153          * Postgres doesn't support selectDB in the same way MySQL does. So if the
 154          * DB name doesn't match the open connection, open a new one
 155          * @param string $db
 156          * @return bool
 157          */
 158         public function selectDB( $db ) {
 159                 if ( $this->mDBname !== $db ) {
 160                         return (bool)$this->open( $this->mServer, $this->mUser, $this->mPassword, $db );
 161                 } else {
 162                         return true;
 163                 }
 164         }
 165
 166         /**
 167          * @param string[] $vars
 168          * @return string
 169          */
 170         private function makeConnectionString( $vars ) {
 171                 $s = '';
 172                 foreach ( $vars as $name => $value ) {
 173                         $s .= "$name='" . str_replace( "'", "\\'", $value ) . "' ";
 174                 }
 175
 176                 return $s;
 177         }
 178
 179         protected function closeConnection() {
 180                 return $this->mConn ? pg_close( $this->mConn ) : true;
 181         }
 182
 183         public function doQuery( $sql ) {
 184                 $conn = $this->getBindingHandle();
 185
 186                 $sql = mb_convert_encoding( $sql, 'UTF-8' );
 187                 // Clear previously left over PQresult
 188                 while ( $res = pg_get_result( $conn ) ) {
 189                         pg_free_result( $res );
 190                 }
 191                 if ( pg_send_query( $conn, $sql ) === false ) {
 192                         throw new DBUnexpectedError( $this, "Unable to post new query to PostgreSQL\n" );
 193                 }
 194                 $this->mLastResult = pg_get_result( $conn );
 195                 $this->mAffectedRows = null;
 196                 if ( pg_result_error( $this->mLastResult ) ) {
 197                         return false;
 198                 }
 199
 200                 return $this->mLastResult;
 201         }
 202
 203         protected function dumpError() {
 204                 $diags = [
 205                         PGSQL_DIAG_SEVERITY,
 206                         PGSQL_DIAG_SQLSTATE,
 207                         PGSQL_DIAG_MESSAGE_PRIMARY,
 208                         PGSQL_DIAG_MESSAGE_DETAIL,
 209                         PGSQL_DIAG_MESSAGE_HINT,
 210                         PGSQL_DIAG_STATEMENT_POSITION,
 211                         PGSQL_DIAG_INTERNAL_POSITION,
 212                         PGSQL_DIAG_INTERNAL_QUERY,
 213                         PGSQL_DIAG_CONTEXT,
 214                         PGSQL_DIAG_SOURCE_FILE,
 215                         PGSQL_DIAG_SOURCE_LINE,
 216                         PGSQL_DIAG_SOURCE_FUNCTION
 217                 ];
 218                 foreach ( $diags as $d ) {
 219                         $this->queryLogger->debug( sprintf( "PgSQL ERROR(%d): %s\n",
 220                                 $d, pg_result_error_field( $this->mLastResult, $d ) ) );
 221                 }
 222         }
 223
 224         public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 225                 if ( $tempIgnore ) {
 226                         /* Check for constraint violation */
 227                         if ( $errno === '23505' ) {
 228                                 parent::reportQueryError( $error, $errno, $sql, $fname, $tempIgnore );
 229
 230                                 return;
 231                         }
 232                 }
 233                 /* Transaction stays in the ERROR state until rolled back */
 234                 if ( $this->mTrxLevel ) {
 235                         $ignore = $this->ignoreErrors( true );
 236                         $this->rollback( __METHOD__ );
 237                         $this->ignoreErrors( $ignore );
 238                 }
 239                 parent::reportQueryError( $error, $errno, $sql, $fname, false );
 240         }
 241
 242         public function freeResult( $res ) {
 243                 if ( $res instanceof ResultWrapper ) {
 244                         $res = $res->result;
 245                 }
 246                 MediaWiki\suppressWarnings();
 247                 $ok = pg_free_result( $res );
 248                 MediaWiki\restoreWarnings();
 249                 if ( !$ok ) {
 250                         throw new DBUnexpectedError( $this, "Unable to free Postgres result\n" );
 251                 }
 252         }
 253
 254         public function fetchObject( $res ) {
 255                 if ( $res instanceof ResultWrapper ) {
 256                         $res = $res->result;
 257                 }
 258                 MediaWiki\suppressWarnings();
 259                 $row = pg_fetch_object( $res );
 260                 MediaWiki\restoreWarnings();
 261                 # @todo FIXME: HACK HACK HACK HACK debug
 262
 263                 # @todo hashar: not sure if the following test really trigger if the object
 264                 #          fetching failed.
 265                 $conn = $this->getBindingHandle();
 266                 if ( pg_last_error( $conn ) ) {
 267                         throw new DBUnexpectedError(
 268                                 $this,
 269                                 'SQL error: ' . htmlspecialchars( pg_last_error( $conn ) )
 270                         );
 271                 }
 272
 273                 return $row;
 274         }
 275
 276         public function fetchRow( $res ) {
 277                 if ( $res instanceof ResultWrapper ) {
 278                         $res = $res->result;
 279                 }
 280                 MediaWiki\suppressWarnings();
 281                 $row = pg_fetch_array( $res );
 282                 MediaWiki\restoreWarnings();
 283
 284                 $conn = $this->getBindingHandle();
 285                 if ( pg_last_error( $conn ) ) {
 286                         throw new DBUnexpectedError(
 287                                 $this,
 288                                 'SQL error: ' . htmlspecialchars( pg_last_error( $conn ) )
 289                         );
 290                 }
 291
 292                 return $row;
 293         }
 294
 295         public function numRows( $res ) {
 296                 if ( $res instanceof ResultWrapper ) {
 297                         $res = $res->result;
 298                 }
 299                 MediaWiki\suppressWarnings();
 300                 $n = pg_num_rows( $res );
 301                 MediaWiki\restoreWarnings();
 302
 303                 $conn = $this->getBindingHandle();
 304                 if ( pg_last_error( $conn ) ) {
 305                         throw new DBUnexpectedError(
 306                                 $this,
 307                                 'SQL error: ' . htmlspecialchars( pg_last_error( $conn ) )
 308                         );
 309                 }
 310
 311                 return $n;
 312         }
 313
 314         public function numFields( $res ) {
 315                 if ( $res instanceof ResultWrapper ) {
 316                         $res = $res->result;
 317                 }
 318
 319                 return pg_num_fields( $res );
 320         }
 321
 322         public function fieldName( $res, $n ) {
 323                 if ( $res instanceof ResultWrapper ) {
 324                         $res = $res->result;
 325                 }
 326
 327                 return pg_field_name( $res, $n );
 328         }
 329
 330         /**
 331          * Return the result of the last call to nextSequenceValue();
 332          * This must be called after nextSequenceValue().
 333          *
 334          * @return int|null
 335          */
 336         public function insertId() {
 337                 return $this->mInsertId;
 338         }
 339
 340         public function dataSeek( $res, $row ) {
 341                 if ( $res instanceof ResultWrapper ) {
 342                         $res = $res->result;
 343                 }
 344
 345                 return pg_result_seek( $res, $row );
 346         }
 347
 348         public function lastError() {
 349                 if ( $this->mConn ) {
 350                         if ( $this->mLastResult ) {
 351                                 return pg_result_error( $this->mLastResult );
 352                         } else {
 353                                 return pg_last_error();
 354                         }
 355                 }
 356
 357                 return $this->getLastPHPError() ?: 'No database connection';
 358         }
 359
 360         public function lastErrno() {
 361                 if ( $this->mLastResult ) {
 362                         return pg_result_error_field( $this->mLastResult, PGSQL_DIAG_SQLSTATE );
 363                 } else {
 364                         return false;
 365                 }
 366         }
 367
 368         public function affectedRows() {
 369                 if ( !is_null( $this->mAffectedRows ) ) {
 370                         // Forced result for simulated queries
 371                         return $this->mAffectedRows;
 372                 }
 373                 if ( empty( $this->mLastResult ) ) {
 374                         return 0;
 375                 }
 376
 377                 return pg_affected_rows( $this->mLastResult );
 378         }
 379
 380         /**
 381          * Estimate rows in dataset
 382          * Returns estimated count, based on EXPLAIN output
 383          * This is not necessarily an accurate estimate, so use sparingly
 384          * Returns -1 if count cannot be found
 385          * Takes same arguments as Database::select()
 386          *
 387          * @param string $table
 388          * @param string $vars
 389          * @param string $conds
 390          * @param string $fname
 391          * @param array $options
 392          * @return int
 393          */
 394         public function estimateRowCount( $table, $vars = '*', $conds = '',
 395                 $fname = __METHOD__, $options = []
 396         ) {
 397                 $options['EXPLAIN'] = true;
 398                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 399                 $rows = -1;
 400                 if ( $res ) {
 401                         $row = $this->fetchRow( $res );
 402                         $count = [];
 403                         if ( preg_match( '/rows=(\d+)/', $row[0], $count ) ) {
 404                                 $rows = (int)$count[1];
 405                         }
 406                 }
 407
 408                 return $rows;
 409         }
 410
 411         public function indexInfo( $table, $index, $fname = __METHOD__ ) {
 412                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='$table'";
 413                 $res = $this->query( $sql, $fname );
 414                 if ( !$res ) {
 415                         return null;
 416                 }
 417                 foreach ( $res as $row ) {
 418                         if ( $row->indexname == $this->indexName( $index ) ) {
 419                                 return $row;
 420                         }
 421                 }
 422
 423                 return false;
 424         }
 425
 426         public function indexAttributes( $index, $schema = false ) {
 427                 if ( $schema === false ) {
 428                         $schema = $this->getCoreSchema();
 429                 }
 430                 /*
 431                  * A subquery would be not needed if we didn't care about the order
 432                  * of attributes, but we do
 433                  */
 434                 $sql = <<<__INDEXATTR__
 435
 436                         SELECT opcname,
 437                                 attname,
 438                                 i.indoption[s.g] as option,
 439                                 pg_am.amname
 440                         FROM
 441                                 (SELECT generate_series(array_lower(isub.indkey,1), array_upper(isub.indkey,1)) AS g
 442                                         FROM
 443                                                 pg_index isub
 444                                         JOIN pg_class cis
 445                                                 ON cis.oid=isub.indexrelid
 446                                         JOIN pg_namespace ns
 447                                                 ON cis.relnamespace = ns.oid
 448                                         WHERE cis.relname='$index' AND ns.nspname='$schema') AS s,
 449                                 pg_attribute,
 450                                 pg_opclass opcls,
 451                                 pg_am,
 452                                 pg_class ci
 453                                 JOIN pg_index i
 454                                         ON ci.oid=i.indexrelid
 455                                 JOIN pg_class ct
 456                                         ON ct.oid = i.indrelid
 457                                 JOIN pg_namespace n
 458                                         ON ci.relnamespace = n.oid
 459                                 WHERE
 460                                         ci.relname='$index' AND n.nspname='$schema'
 461                                         AND     attrelid = ct.oid
 462                                         AND     i.indkey[s.g] = attnum
 463                                         AND     i.indclass[s.g] = opcls.oid
 464                                         AND     pg_am.oid = opcls.opcmethod
 465 __INDEXATTR__;
 466                 $res = $this->query( $sql, __METHOD__ );
 467                 $a = [];
 468                 if ( $res ) {
 469                         foreach ( $res as $row ) {
 470                                 $a[] = [
 471                                         $row->attname,
 472                                         $row->opcname,
 473                                         $row->amname,
 474                                         $row->option ];
 475                         }
 476                 } else {
 477                         return null;
 478                 }
 479
 480                 return $a;
 481         }
 482
 483         public function indexUnique( $table, $index, $fname = __METHOD__ ) {
 484                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='{$table}'" .
 485                         " AND indexdef LIKE 'CREATE UNIQUE%(" .
 486                         $this->strencode( $this->indexName( $index ) ) .
 487                         ")'";
 488                 $res = $this->query( $sql, $fname );
 489                 if ( !$res ) {
 490                         return null;
 491                 }
 492
 493                 return $res->numRows() > 0;
 494         }
 495
 496         public function selectSQLText(
 497                 $table, $vars, $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
 498         ) {
 499                 // Change the FOR UPDATE option as necessary based on the join conditions. Then pass
 500                 // to the parent function to get the actual SQL text.
 501                 // In Postgres when using FOR UPDATE, only the main table and tables that are inner joined
 502                 // can be locked. That means tables in an outer join cannot be FOR UPDATE locked. Trying to
 503                 // do so causes a DB error. This wrapper checks which tables can be locked and adjusts it
 504                 // accordingly.
 505                 // MySQL uses "ORDER BY NULL" as an optimization hint, but that is illegal in PostgreSQL.
 506                 if ( is_array( $options ) ) {
 507                         $forUpdateKey = array_search( 'FOR UPDATE', $options, true );
 508                         if ( $forUpdateKey !== false && $join_conds ) {
 509                                 unset( $options[$forUpdateKey] );
 510
 511                                 foreach ( $join_conds as $table_cond => $join_cond ) {
 512                                         if ( 0 === preg_match( '/^(?:LEFT|RIGHT|FULL)(?: OUTER)? JOIN$/i', $join_cond[0] ) ) {
 513                                                 $options['FOR UPDATE'][] = $table_cond;
 514                                         }
 515                                 }
 516                         }
 517
 518                         if ( isset( $options['ORDER BY'] ) && $options['ORDER BY'] == 'NULL' ) {
 519                                 unset( $options['ORDER BY'] );
 520                         }
 521                 }
 522
 523                 return parent::selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
 524         }
 525
 526         /**
 527          * INSERT wrapper, inserts an array into a table
 528          *
 529          * $args may be a single associative array, or an array of these with numeric keys,
 530          * for multi-row insert (Postgres version 8.2 and above only).
 531          *
 532          * @param string $table Name of the table to insert to.
 533          * @param array $args Items to insert into the table.
 534          * @param string $fname Name of the function, for profiling
 535          * @param array|string $options String or array. Valid options: IGNORE
 536          * @return bool Success of insert operation. IGNORE always returns true.
 537          */
 538         public function insert( $table, $args, $fname = __METHOD__, $options = [] ) {
 539                 if ( !count( $args ) ) {
 540                         return true;
 541                 }
 542
 543                 $table = $this->tableName( $table );
 544                 if ( !isset( $this->numericVersion ) ) {
 545                         $this->getServerVersion();
 546                 }
 547
 548                 if ( !is_array( $options ) ) {
 549                         $options = [ $options ];
 550                 }
 551
 552                 if ( isset( $args[0] ) && is_array( $args[0] ) ) {
 553                         $multi = true;
 554                         $keys = array_keys( $args[0] );
 555                 } else {
 556                         $multi = false;
 557                         $keys = array_keys( $args );
 558                 }
 559
 560                 // If IGNORE is set, we use savepoints to emulate mysql's behavior
 561                 $savepoint = $olde = null;
 562                 $numrowsinserted = 0;
 563                 if ( in_array( 'IGNORE', $options ) ) {
 564                         $savepoint = new SavepointPostgres( $this, 'mw', $this->queryLogger );
 565                         $olde = error_reporting( 0 );
 566                         // For future use, we may want to track the number of actual inserts
 567                         // Right now, insert (all writes) simply return true/false
 568                 }
 569
 570                 $sql = "INSERT INTO $table (" . implode( ',', $keys ) . ') VALUES ';
 571
 572                 if ( $multi ) {
 573                         if ( $this->numericVersion >= 8.2 && !$savepoint ) {
 574                                 $first = true;
 575                                 foreach ( $args as $row ) {
 576                                         if ( $first ) {
 577                                                 $first = false;
 578                                         } else {
 579                                                 $sql .= ',';
 580                                         }
 581                                         $sql .= '(' . $this->makeList( $row ) . ')';
 582                                 }
 583                                 $res = (bool)$this->query( $sql, $fname, $savepoint );
 584                         } else {
 585                                 $res = true;
 586                                 $origsql = $sql;
 587                                 foreach ( $args as $row ) {
 588                                         $tempsql = $origsql;
 589                                         $tempsql .= '(' . $this->makeList( $row ) . ')';
 590
 591                                         if ( $savepoint ) {
 592                                                 $savepoint->savepoint();
 593                                         }
 594
 595                                         $tempres = (bool)$this->query( $tempsql, $fname, $savepoint );
 596
 597                                         if ( $savepoint ) {
 598                                                 $bar = pg_result_error( $this->mLastResult );
 599                                                 if ( $bar != false ) {
 600                                                         $savepoint->rollback();
 601                                                 } else {
 602                                                         $savepoint->release();
 603                                                         $numrowsinserted++;
 604                                                 }
 605                                         }
 606
 607                                         // If any of them fail, we fail overall for this function call
 608                                         // Note that this will be ignored if IGNORE is set
 609                                         if ( !$tempres ) {
 610                                                 $res = false;
 611                                         }
 612                                 }
 613                         }
 614                 } else {
 615                         // Not multi, just a lone insert
 616                         if ( $savepoint ) {
 617                                 $savepoint->savepoint();
 618                         }
 619
 620                         $sql .= '(' . $this->makeList( $args ) . ')';
 621                         $res = (bool)$this->query( $sql, $fname, $savepoint );
 622                         if ( $savepoint ) {
 623                                 $bar = pg_result_error( $this->mLastResult );
 624                                 if ( $bar != false ) {
 625                                         $savepoint->rollback();
 626                                 } else {
 627                                         $savepoint->release();
 628                                         $numrowsinserted++;
 629                                 }
 630                         }
 631                 }
 632                 if ( $savepoint ) {
 633                         error_reporting( $olde );
 634                         $savepoint->commit();
 635
 636                         // Set the affected row count for the whole operation
 637                         $this->mAffectedRows = $numrowsinserted;
 638
 639                         // IGNORE always returns true
 640                         return true;
 641                 }
 642
 643                 return $res;
 644         }
 645
 646         /**
 647          * INSERT SELECT wrapper
 648          * $varMap must be an associative array of the form [ 'dest1' => 'source1', ... ]
 649          * Source items may be literals rather then field names, but strings should
 650          * be quoted with Database::addQuotes()
 651          * $conds may be "*" to copy the whole table
 652          * srcTable may be an array of tables.
 653          * @todo FIXME: Implement this a little better (seperate select/insert)?
 654          *
 655          * @param string $destTable
 656          * @param array|string $srcTable
 657          * @param array $varMap
 658          * @param array $conds
 659          * @param string $fname
 660          * @param array $insertOptions
 661          * @param array $selectOptions
 662          * @return bool
 663          */
 664         public function nativeInsertSelect(
 665                 $destTable, $srcTable, $varMap, $conds, $fname = __METHOD__,
 666                 $insertOptions = [], $selectOptions = []
 667         ) {
 668                 $destTable = $this->tableName( $destTable );
 669
 670                 if ( !is_array( $insertOptions ) ) {
 671                         $insertOptions = [ $insertOptions ];
 672                 }
 673
 674                 /*
 675                  * If IGNORE is set, we use savepoints to emulate mysql's behavior
 676                  * Ignore LOW PRIORITY option, since it is MySQL-specific
 677                  */
 678                 $savepoint = $olde = null;
 679                 $numrowsinserted = 0;
 680                 if ( in_array( 'IGNORE', $insertOptions ) ) {
 681                         $savepoint = new SavepointPostgres( $this, 'mw', $this->queryLogger );
 682                         $olde = error_reporting( 0 );
 683                         $savepoint->savepoint();
 684                 }
 685
 686                 if ( !is_array( $selectOptions ) ) {
 687                         $selectOptions = [ $selectOptions ];
 688                 }
 689                 list( $startOpts, $useIndex, $tailOpts, $ignoreIndex ) =
 690                         $this->makeSelectOptions( $selectOptions );
 691                 if ( is_array( $srcTable ) ) {
 692                         $srcTable = implode( ',', array_map( [ &$this, 'tableName' ], $srcTable ) );
 693                 } else {
 694                         $srcTable = $this->tableName( $srcTable );
 695                 }
 696
 697                 $sql = "INSERT INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
 698                         " SELECT $startOpts " . implode( ',', $varMap ) .
 699                         " FROM $srcTable $useIndex $ignoreIndex ";
 700
 701                 if ( $conds != '*' ) {
 702                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
 703                 }
 704
 705                 $sql .= " $tailOpts";
 706
 707                 $res = (bool)$this->query( $sql, $fname, $savepoint );
 708                 if ( $savepoint ) {
 709                         $bar = pg_result_error( $this->mLastResult );
 710                         if ( $bar != false ) {
 711                                 $savepoint->rollback();
 712                         } else {
 713                                 $savepoint->release();
 714                                 $numrowsinserted++;
 715                         }
 716                         error_reporting( $olde );
 717                         $savepoint->commit();
 718
 719                         // Set the affected row count for the whole operation
 720                         $this->mAffectedRows = $numrowsinserted;
 721
 722                         // IGNORE always returns true
 723                         return true;
 724                 }
 725
 726                 return $res;
 727         }
 728
 729         public function tableName( $name, $format = 'quoted' ) {
 730                 // Replace reserved words with better ones
 731                 $name = $this->remappedTableName( $name );
 732
 733                 return parent::tableName( $name, $format );
 734         }
 735
 736         /**
 737          * @param string $name
 738          * @return string Value of $name or remapped name if $name is a reserved keyword
 739          * @TODO: dependency inject these...
 740          */
 741         public function remappedTableName( $name ) {
 742                 if ( $name === 'user' ) {
 743                         return 'mwuser';
 744                 } elseif ( $name === 'text' ) {
 745                         return 'pagecontent';
 746                 }
 747
 748                 return $name;
 749         }
 750
 751         /**
 752          * @param string $name
 753          * @param string $format
 754          * @return string Qualified and encoded (if requested) table name
 755          */
 756         public function realTableName( $name, $format = 'quoted' ) {
 757                 return parent::tableName( $name, $format );
 758         }
 759
 760         public function nextSequenceValue( $seqName ) {
 761                 $safeseq = str_replace( "'", "''", $seqName );
 762                 $res = $this->query( "SELECT nextval('$safeseq')" );
 763                 $row = $this->fetchRow( $res );
 764                 $this->mInsertId = $row[0];
 765
 766                 return $this->mInsertId;
 767         }
 768
 769         /**
 770          * Return the current value of a sequence. Assumes it has been nextval'ed in this session.
 771          *
 772          * @param string $seqName
 773          * @return int
 774          */
 775         public function currentSequenceValue( $seqName ) {
 776                 $safeseq = str_replace( "'", "''", $seqName );
 777                 $res = $this->query( "SELECT currval('$safeseq')" );
 778                 $row = $this->fetchRow( $res );
 779                 $currval = $row[0];
 780
 781                 return $currval;
 782         }
 783
 784         public function textFieldSize( $table, $field ) {
 785                 $table = $this->tableName( $table );
 786                 $sql = "SELECT t.typname as ftype,a.atttypmod as size
 787                         FROM pg_class c, pg_attribute a, pg_type t
 788                         WHERE relname='$table' AND a.attrelid=c.oid AND
 789                                 a.atttypid=t.oid and a.attname='$field'";
 790                 $res = $this->query( $sql );
 791                 $row = $this->fetchObject( $res );
 792                 if ( $row->ftype == 'varchar' ) {
 793                         $size = $row->size - 4;
 794                 } else {
 795                         $size = $row->size;
 796                 }
 797
 798                 return $size;
 799         }
 800
 801         public function limitResult( $sql, $limit, $offset = false ) {
 802                 return "$sql LIMIT $limit " . ( is_numeric( $offset ) ? " OFFSET {$offset} " : '' );
 803         }
 804
 805         public function wasDeadlock() {
 806                 return $this->lastErrno() == '40P01';
 807         }
 808
 809         public function duplicateTableStructure(
 810                 $oldName, $newName, $temporary = false, $fname = __METHOD__
 811         ) {
 812                 $newName = $this->addIdentifierQuotes( $newName );
 813                 $oldName = $this->addIdentifierQuotes( $oldName );
 814
 815                 return $this->query( 'CREATE ' . ( $temporary ? 'TEMPORARY ' : '' ) . " TABLE $newName " .
 816                         "(LIKE $oldName INCLUDING DEFAULTS)", $fname );
 817         }
 818
 819         public function listTables( $prefix = null, $fname = __METHOD__ ) {
 820                 $eschema = $this->addQuotes( $this->getCoreSchema() );
 821                 $result = $this->query(
 822                         "SELECT tablename FROM pg_tables WHERE schemaname = $eschema", $fname );
 823                 $endArray = [];
 824
 825                 foreach ( $result as $table ) {
 826                         $vars = get_object_vars( $table );
 827                         $table = array_pop( $vars );
 828                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
 829                                 $endArray[] = $table;
 830                         }
 831                 }
 832
 833                 return $endArray;
 834         }
 835
 836         public function timestamp( $ts = 0 ) {
 837                 $ct = new ConvertibleTimestamp( $ts );
 838
 839                 return $ct->getTimestamp( TS_POSTGRES );
 840         }
 841
 842         /**
 843          * Posted by cc[plus]php[at]c2se[dot]com on 25-Mar-2009 09:12
 844          * to https://secure.php.net/manual/en/ref.pgsql.php
 845          *
 846          * Parsing a postgres array can be a tricky problem, he's my
 847          * take on this, it handles multi-dimensional arrays plus
 848          * escaping using a nasty regexp to determine the limits of each
 849          * data-item.
 850          *
 851          * This should really be handled by PHP PostgreSQL module
 852          *
 853          * @since 1.19
 854          * @param string $text Postgreql array returned in a text form like {a,b}
 855          * @param string $output
 856          * @param int|bool $limit
 857          * @param int $offset
 858          * @return string
 859          */
 860         private function pg_array_parse( $text, &$output, $limit = false, $offset = 1 ) {
 861                 if ( false === $limit ) {
 862                         $limit = strlen( $text ) - 1;
 863                         $output = [];
 864                 }
 865                 if ( '{}' == $text ) {
 866                         return $output;
 867                 }
 868                 do {
 869                         if ( '{' != $text[$offset] ) {
 870                                 preg_match( "/(\\{?\"([^\"\\\\]|\\\\.)*\"|[^,{}]+)+([,}]+)/",
 871                                         $text, $match, 0, $offset );
 872                                 $offset += strlen( $match[0] );
 873                                 $output[] = ( '"' != $match[1][0]
 874                                         ? $match[1]
 875                                         : stripcslashes( substr( $match[1], 1, -1 ) ) );
 876                                 if ( '},' == $match[3] ) {
 877                                         return $output;
 878                                 }
 879                         } else {
 880                                 $offset = $this->pg_array_parse( $text, $output, $limit, $offset + 1 );
 881                         }
 882                 } while ( $limit > $offset );
 883
 884                 return $output;
 885         }
 886
 887         public function aggregateValue( $valuedata, $valuename = 'value' ) {
 888                 return $valuedata;
 889         }
 890
 891         public function getSoftwareLink() {
 892                 return '[{{int:version-db-postgres-url}} PostgreSQL]';
 893         }
 894
 895         /**
 896          * Return current schema (executes SELECT current_schema())
 897          * Needs transaction
 898          *
 899          * @since 1.19
 900          * @return string Default schema for the current session
 901          */
 902         public function getCurrentSchema() {
 903                 $res = $this->query( "SELECT current_schema()", __METHOD__ );
 904                 $row = $this->fetchRow( $res );
 905
 906                 return $row[0];
 907         }
 908
 909         /**
 910          * Return list of schemas which are accessible without schema name
 911          * This is list does not contain magic keywords like "$user"
 912          * Needs transaction
 913          *
 914          * @see getSearchPath()
 915          * @see setSearchPath()
 916          * @since 1.19
 917          * @return array List of actual schemas for the current sesson
 918          */
 919         public function getSchemas() {
 920                 $res = $this->query( "SELECT current_schemas(false)", __METHOD__ );
 921                 $row = $this->fetchRow( $res );
 922                 $schemas = [];
 923
 924                 /* PHP pgsql support does not support array type, "{a,b}" string is returned */
 925
 926                 return $this->pg_array_parse( $row[0], $schemas );
 927         }
 928
 929         /**
 930          * Return search patch for schemas
 931          * This is different from getSchemas() since it contain magic keywords
 932          * (like "$user").
 933          * Needs transaction
 934          *
 935          * @since 1.19
 936          * @return array How to search for table names schemas for the current user
 937          */
 938         public function getSearchPath() {
 939                 $res = $this->query( "SHOW search_path", __METHOD__ );
 940                 $row = $this->fetchRow( $res );
 941
 942                 /* PostgreSQL returns SHOW values as strings */
 943
 944                 return explode( ",", $row[0] );
 945         }
 946
 947         /**
 948          * Update search_path, values should already be sanitized
 949          * Values may contain magic keywords like "$user"
 950          * @since 1.19
 951          *
 952          * @param array $search_path List of schemas to be searched by default
 953          */
 954         private function setSearchPath( $search_path ) {
 955                 $this->query( "SET search_path = " . implode( ", ", $search_path ) );
 956         }
 957
 958         /**
 959          * Determine default schema for the current application
 960          * Adjust this session schema search path if desired schema exists
 961          * and is not alread there.
 962          *
 963          * We need to have name of the core schema stored to be able
 964          * to query database metadata.
 965          *
 966          * This will be also called by the installer after the schema is created
 967          *
 968          * @since 1.19
 969          *
 970          * @param string $desiredSchema
 971          */
 972         public function determineCoreSchema( $desiredSchema ) {
 973                 $this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
 974                 if ( $this->schemaExists( $desiredSchema ) ) {
 975                         if ( in_array( $desiredSchema, $this->getSchemas() ) ) {
 976                                 $this->mCoreSchema = $desiredSchema;
 977                                 $this->queryLogger->debug(
 978                                         "Schema \"" . $desiredSchema . "\" already in the search path\n" );
 979                         } else {
 980                                 /**
 981                                  * Prepend our schema (e.g. 'mediawiki') in front
 982                                  * of the search path
 983                                  * Fixes bug 15816
 984                                  */
 985                                 $search_path = $this->getSearchPath();
 986                                 array_unshift( $search_path,
 987                                         $this->addIdentifierQuotes( $desiredSchema ) );
 988                                 $this->setSearchPath( $search_path );
 989                                 $this->mCoreSchema = $desiredSchema;
 990                                 $this->queryLogger->debug(
 991                                         "Schema \"" . $desiredSchema . "\" added to the search path\n" );
 992                         }
 993                 } else {
 994                         $this->mCoreSchema = $this->getCurrentSchema();
 995                         $this->queryLogger->debug(
 996                                 "Schema \"" . $desiredSchema . "\" not found, using current \"" .
 997                                 $this->mCoreSchema . "\"\n" );
 998                 }
 999                 /* Commit SET otherwise it will be rollbacked on error or IGNORE SELECT */
1000                 $this->commit( __METHOD__, self::FLUSHING_INTERNAL );
1001         }
1002
1003         /**
1004          * Return schema name for core application tables
1005          *
1006          * @since 1.19
1007          * @return string Core schema name
1008          */
1009         public function getCoreSchema() {
1010                 return $this->mCoreSchema;
1011         }
1012
1013         public function getServerVersion() {
1014                 if ( !isset( $this->numericVersion ) ) {
1015                         $conn = $this->getBindingHandle();
1016                         $versionInfo = pg_version( $conn );
1017                         if ( version_compare( $versionInfo['client'], '7.4.0', 'lt' ) ) {
1018                                 // Old client, abort install
1019                                 $this->numericVersion = '7.3 or earlier';
1020                         } elseif ( isset( $versionInfo['server'] ) ) {
1021                                 // Normal client
1022                                 $this->numericVersion = $versionInfo['server'];
1023                         } else {
1024                                 // Bug 16937: broken pgsql extension from PHP<5.3
1025                                 $this->numericVersion = pg_parameter_status( $conn, 'server_version' );
1026                         }
1027                 }
1028
1029                 return $this->numericVersion;
1030         }
1031
1032         /**
1033          * Query whether a given relation exists (in the given schema, or the
1034          * default mw one if not given)
1035          * @param string $table
1036          * @param array|string $types
1037          * @param bool|string $schema
1038          * @return bool
1039          */
1040         private function relationExists( $table, $types, $schema = false ) {
1041                 if ( !is_array( $types ) ) {
1042                         $types = [ $types ];
1043                 }
1044                 if ( $schema === false ) {
1045                         $schema = $this->getCoreSchema();
1046                 }
1047                 $etable = $this->addQuotes( $table );
1048                 $eschema = $this->addQuotes( $schema );
1049                 $sql = "SELECT 1 FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n "
1050                         . "WHERE c.relnamespace = n.oid AND c.relname = $etable AND n.nspname = $eschema "
1051                         . "AND c.relkind IN ('" . implode( "','", $types ) . "')";
1052                 $res = $this->query( $sql );
1053                 $count = $res ? $res->numRows() : 0;
1054
1055                 return (bool)$count;
1056         }
1057
1058         /**
1059          * For backward compatibility, this function checks both tables and views.
1060          * @param string $table
1061          * @param string $fname
1062          * @param bool|string $schema
1063          * @return bool
1064          */
1065         public function tableExists( $table, $fname = __METHOD__, $schema = false ) {
1066                 return $this->relationExists( $table, [ 'r', 'v' ], $schema );
1067         }
1068
1069         public function sequenceExists( $sequence, $schema = false ) {
1070                 return $this->relationExists( $sequence, 'S', $schema );
1071         }
1072
1073         public function triggerExists( $table, $trigger ) {
1074                 $q = <<<SQL
1075         SELECT 1 FROM pg_class, pg_namespace, pg_trigger
1076                 WHERE relnamespace=pg_namespace.oid AND relkind='r'
1077                           AND tgrelid=pg_class.oid
1078                           AND nspname=%s AND relname=%s AND tgname=%s
1079 SQL;
1080                 $res = $this->query(
1081                         sprintf(
1082                                 $q,
1083                                 $this->addQuotes( $this->getCoreSchema() ),
1084                                 $this->addQuotes( $table ),
1085                                 $this->addQuotes( $trigger )
1086                         )
1087                 );
1088                 if ( !$res ) {
1089                         return null;
1090                 }
1091                 $rows = $res->numRows();
1092
1093                 return $rows;
1094         }
1095
1096         public function ruleExists( $table, $rule ) {
1097                 $exists = $this->selectField( 'pg_rules', 'rulename',
1098                         [
1099                                 'rulename' => $rule,
1100                                 'tablename' => $table,
1101                                 'schemaname' => $this->getCoreSchema()
1102                         ]
1103                 );
1104
1105                 return $exists === $rule;
1106         }
1107
1108         public function constraintExists( $table, $constraint ) {
1109                 $sql = sprintf( "SELECT 1 FROM information_schema.table_constraints " .
1110                         "WHERE constraint_schema = %s AND table_name = %s AND constraint_name = %s",
1111                         $this->addQuotes( $this->getCoreSchema() ),
1112                         $this->addQuotes( $table ),
1113                         $this->addQuotes( $constraint )
1114                 );
1115                 $res = $this->query( $sql );
1116                 if ( !$res ) {
1117                         return null;
1118                 }
1119                 $rows = $res->numRows();
1120
1121                 return $rows;
1122         }
1123
1124         /**
1125          * Query whether a given schema exists. Returns true if it does, false if it doesn't.
1126          * @param string $schema
1127          * @return bool
1128          */
1129         public function schemaExists( $schema ) {
1130                 if ( !strlen( $schema ) ) {
1131                         return false; // short-circuit
1132                 }
1133
1134                 $exists = $this->selectField(
1135                         '"pg_catalog"."pg_namespace"', 1, [ 'nspname' => $schema ], __METHOD__ );
1136
1137                 return (bool)$exists;
1138         }
1139
1140         /**
1141          * Returns true if a given role (i.e. user) exists, false otherwise.
1142          * @param string $roleName
1143          * @return bool
1144          */
1145         public function roleExists( $roleName ) {
1146                 $exists = $this->selectField( '"pg_catalog"."pg_roles"', 1,
1147                         [ 'rolname' => $roleName ], __METHOD__ );
1148
1149                 return (bool)$exists;
1150         }
1151
1152         /**
1153          * @var string $table
1154          * @var string $field
1155          * @return PostgresField|null
1156          */
1157         public function fieldInfo( $table, $field ) {
1158                 return PostgresField::fromText( $this, $table, $field );
1159         }
1160
1161         /**
1162          * pg_field_type() wrapper
1163          * @param ResultWrapper|resource $res ResultWrapper or PostgreSQL query result resource
1164          * @param int $index Field number, starting from 0
1165          * @return string
1166          */
1167         public function fieldType( $res, $index ) {
1168                 if ( $res instanceof ResultWrapper ) {
1169                         $res = $res->result;
1170                 }
1171
1172                 return pg_field_type( $res, $index );
1173         }
1174
1175         public function encodeBlob( $b ) {
1176                 return new PostgresBlob( pg_escape_bytea( $b ) );
1177         }
1178
1179         public function decodeBlob( $b ) {
1180                 if ( $b instanceof PostgresBlob ) {
1181                         $b = $b->fetch();
1182                 } elseif ( $b instanceof Blob ) {
1183                         return $b->fetch();
1184                 }
1185
1186                 return pg_unescape_bytea( $b );
1187         }
1188
1189         public function strencode( $s ) {
1190                 // Should not be called by us
1191                 return pg_escape_string( $this->getBindingHandle(), $s );
1192         }
1193
1194         public function addQuotes( $s ) {
1195                 $conn = $this->getBindingHandle();
1196
1197                 if ( is_null( $s ) ) {
1198                         return 'NULL';
1199                 } elseif ( is_bool( $s ) ) {
1200                         return intval( $s );
1201                 } elseif ( $s instanceof Blob ) {
1202                         if ( $s instanceof PostgresBlob ) {
1203                                 $s = $s->fetch();
1204                         } else {
1205                                 $s = pg_escape_bytea( $conn, $s->fetch() );
1206                         }
1207                         return "'$s'";
1208                 }
1209
1210                 return "'" . pg_escape_string( $conn, $s ) . "'";
1211         }
1212
1213         /**
1214          * Postgres specific version of replaceVars.
1215          * Calls the parent version in Database.php
1216          *
1217          * @param string $ins SQL string, read from a stream (usually tables.sql)
1218          * @return string SQL string
1219          */
1220         protected function replaceVars( $ins ) {
1221                 $ins = parent::replaceVars( $ins );
1222
1223                 if ( $this->numericVersion >= 8.3 ) {
1224                         // Thanks for not providing backwards-compatibility, 8.3
1225                         $ins = preg_replace( "/to_tsvector\s*\(\s*'default'\s*,/", 'to_tsvector(', $ins );
1226                 }
1227
1228                 if ( $this->numericVersion <= 8.1 ) { // Our minimum version
1229                         $ins = str_replace( 'USING gin', 'USING gist', $ins );
1230                 }
1231
1232                 return $ins;
1233         }
1234
1235         public function makeSelectOptions( $options ) {
1236                 $preLimitTail = $postLimitTail = '';
1237                 $startOpts = $useIndex = $ignoreIndex = '';
1238
1239                 $noKeyOptions = [];
1240                 foreach ( $options as $key => $option ) {
1241                         if ( is_numeric( $key ) ) {
1242                                 $noKeyOptions[$option] = true;
1243                         }
1244                 }
1245
1246                 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1247
1248                 $preLimitTail .= $this->makeOrderBy( $options );
1249
1250                 // if ( isset( $options['LIMIT'] ) ) {
1251                 //      $tailOpts .= $this->limitResult( '', $options['LIMIT'],
1252                 //              isset( $options['OFFSET'] ) ? $options['OFFSET']
1253                 //              : false );
1254                 // }
1255
1256                 if ( isset( $options['FOR UPDATE'] ) ) {
1257                         $postLimitTail .= ' FOR UPDATE OF ' .
1258                                 implode( ', ', array_map( [ &$this, 'tableName' ], $options['FOR UPDATE'] ) );
1259                 } elseif ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1260                         $postLimitTail .= ' FOR UPDATE';
1261                 }
1262
1263                 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1264                         $startOpts .= 'DISTINCT';
1265                 }
1266
1267                 return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ];
1268         }
1269
1270         public function getDBname() {
1271                 return $this->mDBname;
1272         }
1273
1274         public function getServer() {
1275                 return $this->mServer;
1276         }
1277
1278         public function buildConcat( $stringList ) {
1279                 return implode( ' || ', $stringList );
1280         }
1281
1282         public function buildGroupConcatField(
1283                 $delimiter, $table, $field, $conds = '', $options = [], $join_conds = []
1284         ) {
1285                 $fld = "array_to_string(array_agg($field)," . $this->addQuotes( $delimiter ) . ')';
1286
1287                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
1288         }
1289
1290         public function buildStringCast( $field ) {
1291                 return $field . '::text';
1292         }
1293
1294         public function streamStatementEnd( &$sql, &$newLine ) {
1295                 # Allow dollar quoting for function declarations
1296                 if ( substr( $newLine, 0, 4 ) == '$mw$' ) {
1297                         if ( $this->delimiter ) {
1298                                 $this->delimiter = false;
1299                         } else {
1300                                 $this->delimiter = ';';
1301                         }
1302                 }
1303
1304                 return parent::streamStatementEnd( $sql, $newLine );
1305         }
1306
1307         public function lockIsFree( $lockName, $method ) {
1308                 // http://www.postgresql.org/docs/8.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1309                 $key = $this->addQuotes( $this->bigintFromLockName( $lockName ) );
1310                 $result = $this->query( "SELECT (CASE(pg_try_advisory_lock($key))
1311                         WHEN 'f' THEN 'f' ELSE pg_advisory_unlock($key) END) AS lockstatus", $method );
1312                 $row = $this->fetchObject( $result );
1313
1314                 return ( $row->lockstatus === 't' );
1315         }
1316
1317         public function lock( $lockName, $method, $timeout = 5 ) {
1318                 // http://www.postgresql.org/docs/8.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1319                 $key = $this->addQuotes( $this->bigintFromLockName( $lockName ) );
1320                 $loop = new WaitConditionLoop(
1321                         function () use ( $lockName, $key, $timeout, $method ) {
1322                                 $res = $this->query( "SELECT pg_try_advisory_lock($key) AS lockstatus", $method );
1323                                 $row = $this->fetchObject( $res );
1324                                 if ( $row->lockstatus === 't' ) {
1325                                         parent::lock( $lockName, $method, $timeout ); // record
1326                                         return true;
1327                                 }
1328
1329                                 return WaitConditionLoop::CONDITION_CONTINUE;
1330                         },
1331                         $timeout
1332                 );
1333
1334                 return ( $loop->invoke() === $loop::CONDITION_REACHED );
1335         }
1336
1337         public function unlock( $lockName, $method ) {
1338                 // http://www.postgresql.org/docs/8.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1339                 $key = $this->addQuotes( $this->bigintFromLockName( $lockName ) );
1340                 $result = $this->query( "SELECT pg_advisory_unlock($key) as lockstatus", $method );
1341                 $row = $this->fetchObject( $result );
1342
1343                 if ( $row->lockstatus === 't' ) {
1344                         parent::unlock( $lockName, $method ); // record
1345                         return true;
1346                 }
1347
1348                 $this->queryLogger->debug( __METHOD__ . " failed to release lock\n" );
1349
1350                 return false;
1351         }
1352
1353         /**
1354          * @param string $lockName
1355          * @return string Integer
1356          */
1357         private function bigintFromLockName( $lockName ) {
1358                 return Wikimedia\base_convert( substr( sha1( $lockName ), 0, 15 ), 16, 10 );
1359         }
1360 }