includes/db/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
  24 class PostgresField implements Field {
  25         private $name, $tablename, $type, $nullable, $max_length, $deferred, $deferrable, $conname,
  26                 $has_default, $default;
  27
  28         /**
  29          * @param $db DatabaseBase
  30          * @param  $table
  31          * @param  $field
  32          * @return null|PostgresField
  33          */
  34         static function fromText( $db, $table, $field ) {
  35                 $q = <<<SQL
  36 SELECT
  37  attnotnull, attlen, conname AS conname,
  38  atthasdef,
  39  adsrc,
  40  COALESCE(condeferred, 'f') AS deferred,
  41  COALESCE(condeferrable, 'f') AS deferrable,
  42  CASE WHEN typname = 'int2' THEN 'smallint'
  43   WHEN typname = 'int4' THEN 'integer'
  44   WHEN typname = 'int8' THEN 'bigint'
  45   WHEN typname = 'bpchar' THEN 'char'
  46  ELSE typname END AS typname
  47 FROM pg_class c
  48 JOIN pg_namespace n ON (n.oid = c.relnamespace)
  49 JOIN pg_attribute a ON (a.attrelid = c.oid)
  50 JOIN pg_type t ON (t.oid = a.atttypid)
  51 LEFT JOIN pg_constraint o ON (o.conrelid = c.oid AND a.attnum = ANY(o.conkey) AND o.contype = 'f')
  52 LEFT JOIN pg_attrdef d on c.oid=d.adrelid and a.attnum=d.adnum
  53 WHERE relkind = 'r'
  54 AND nspname=%s
  55 AND relname=%s
  56 AND attname=%s;
  57 SQL;
  58
  59                 $table = $db->tableName( $table, 'raw' );
  60                 $res = $db->query(
  61                         sprintf( $q,
  62                                 $db->addQuotes( $db->getCoreSchema() ),
  63                                 $db->addQuotes( $table ),
  64                                 $db->addQuotes( $field )
  65                         )
  66                 );
  67                 $row = $db->fetchObject( $res );
  68                 if ( !$row ) {
  69                         return null;
  70                 }
  71                 $n = new PostgresField;
  72                 $n->type = $row->typname;
  73                 $n->nullable = ( $row->attnotnull == 'f' );
  74                 $n->name = $field;
  75                 $n->tablename = $table;
  76                 $n->max_length = $row->attlen;
  77                 $n->deferrable = ( $row->deferrable == 't' );
  78                 $n->deferred = ( $row->deferred == 't' );
  79                 $n->conname = $row->conname;
  80                 $n->has_default = ( $row->atthasdef === 't' );
  81                 $n->default = $row->adsrc;
  82                 return $n;
  83         }
  84
  85         function name() {
  86                 return $this->name;
  87         }
  88
  89         function tableName() {
  90                 return $this->tablename;
  91         }
  92
  93         function type() {
  94                 return $this->type;
  95         }
  96
  97         function isNullable() {
  98                 return $this->nullable;
  99         }
 100
 101         function maxLength() {
 102                 return $this->max_length;
 103         }
 104
 105         function is_deferrable() {
 106                 return $this->deferrable;
 107         }
 108
 109         function is_deferred() {
 110                 return $this->deferred;
 111         }
 112
 113         function conname() {
 114                 return $this->conname;
 115         }
 116         /**
 117          * @since 1.19
 118          */
 119         function defaultValue() {
 120                 if( $this->has_default ) {
 121                         return $this->default;
 122                 } else {
 123                         return false;
 124                 }
 125         }
 126
 127 }
 128
 129 /**
 130  * Used to debug transaction processing
 131  * Only used if $wgDebugDBTransactions is true
 132  *
 133  * @since 1.19
 134  * @ingroup Database
 135  */
 136 class PostgresTransactionState {
 137
 138         static $WATCHED = array(
 139                 array(
 140                         "desc" => "%s: Connection state changed from %s -> %s\n",
 141                         "states" => array(
 142                                 PGSQL_CONNECTION_OK       => "OK",
 143                                 PGSQL_CONNECTION_BAD      => "BAD"
 144                         )
 145                 ),
 146                 array(
 147                         "desc" => "%s: Transaction state changed from %s -> %s\n",
 148                         "states" => array(
 149                                 PGSQL_TRANSACTION_IDLE    => "IDLE",
 150                                 PGSQL_TRANSACTION_ACTIVE  => "ACTIVE",
 151                                 PGSQL_TRANSACTION_INTRANS => "TRANS",
 152                                 PGSQL_TRANSACTION_INERROR => "ERROR",
 153                                 PGSQL_TRANSACTION_UNKNOWN => "UNKNOWN"
 154                         )
 155                 )
 156         );
 157
 158         public function __construct( $conn ) {
 159                 $this->mConn = $conn;
 160                 $this->update();
 161                 $this->mCurrentState = $this->mNewState;
 162         }
 163
 164         public function update() {
 165                 $this->mNewState = array(
 166                         pg_connection_status( $this->mConn ),
 167                         pg_transaction_status( $this->mConn )
 168                 );
 169         }
 170
 171         public function check() {
 172                 global $wgDebugDBTransactions;
 173                 $this->update();
 174                 if ( $wgDebugDBTransactions ) {
 175                         if ( $this->mCurrentState !== $this->mNewState ) {
 176                                 $old = reset( $this->mCurrentState );
 177                                 $new = reset( $this->mNewState );
 178                                 foreach ( self::$WATCHED as $watched ) {
 179                                         if ( $old !== $new ) {
 180                                                 $this->log_changed( $old, $new, $watched );
 181                                         }
 182                                         $old = next( $this->mCurrentState );
 183                                         $new = next( $this->mNewState );
 184
 185                                 }
 186                         }
 187                 }
 188                 $this->mCurrentState = $this->mNewState;
 189         }
 190
 191         protected function describe_changed( $status, $desc_table ) {
 192                 if( isset( $desc_table[$status] ) ) {
 193                         return $desc_table[$status];
 194                 } else {
 195                         return "STATUS " . $status;
 196                 }
 197         }
 198
 199         protected function log_changed( $old, $new, $watched ) {
 200                 wfDebug( sprintf( $watched["desc"],
 201                         $this->mConn,
 202                         $this->describe_changed( $old, $watched["states"] ),
 203                         $this->describe_changed( $new, $watched["states"] )
 204                 ) );
 205         }
 206 }
 207
 208 /**
 209  * Manage savepoints within a transaction
 210  * @ingroup Database
 211  * @since 1.19
 212  */
 213 class SavepointPostgres {
 214         /**
 215          * Establish a savepoint within a transaction
 216          */
 217         protected $dbw;
 218         protected $id;
 219         protected $didbegin;
 220
 221         public function __construct ( $dbw, $id ) {
 222                 $this->dbw = $dbw;
 223                 $this->id = $id;
 224                 $this->didbegin = false;
 225                 /* If we are not in a transaction, we need to be for savepoint trickery */
 226                 if ( !$dbw->trxLevel() ) {
 227                                 $dbw->begin( "FOR SAVEPOINT" );
 228                                 $this->didbegin = true;
 229                 }
 230         }
 231
 232         public function __destruct() {
 233                 if ( $this->didbegin ) {
 234                         $this->dbw->rollback();
 235                         $this->didbegin = false;
 236                 }
 237         }
 238
 239         public function commit() {
 240                 if ( $this->didbegin ) {
 241                         $this->dbw->commit();
 242                         $this->didbegin = false;
 243                 }
 244         }
 245
 246         protected function query( $keyword, $msg_ok, $msg_failed ) {
 247                 global $wgDebugDBTransactions;
 248                 if ( $this->dbw->doQuery( $keyword . " " . $this->id ) !== false ) {
 249                         if ( $wgDebugDBTransactions ) {
 250                                 wfDebug( sprintf ( $msg_ok, $this->id ) );
 251                         }
 252                 } else {
 253                         wfDebug( sprintf ( $msg_failed, $this->id ) );
 254                 }
 255         }
 256
 257         public function savepoint() {
 258                 $this->query( "SAVEPOINT",
 259                         "Transaction state: savepoint \"%s\" established.\n",
 260                         "Transaction state: establishment of savepoint \"%s\" FAILED.\n"
 261                 );
 262         }
 263
 264         public function release() {
 265                 $this->query( "RELEASE",
 266                         "Transaction state: savepoint \"%s\" released.\n",
 267                         "Transaction state: release of savepoint \"%s\" FAILED.\n"
 268                 );
 269         }
 270
 271         public function rollback() {
 272                 $this->query( "ROLLBACK TO",
 273                         "Transaction state: savepoint \"%s\" rolled back.\n",
 274                         "Transaction state: rollback of savepoint \"%s\" FAILED.\n"
 275                 );
 276         }
 277
 278         public function __toString() {
 279                 return (string)$this->id;
 280         }
 281 }
 282
 283 /**
 284  * @ingroup Database
 285  */
 286 class DatabasePostgres extends DatabaseBase {
 287         var $mInsertId = null;
 288         var $mLastResult = null;
 289         var $numeric_version = null;
 290         var $mAffectedRows = null;
 291
 292         function getType() {
 293                 return 'postgres';
 294         }
 295
 296         function cascadingDeletes() {
 297                 return true;
 298         }
 299         function cleanupTriggers() {
 300                 return true;
 301         }
 302         function strictIPs() {
 303                 return true;
 304         }
 305         function realTimestamps() {
 306                 return true;
 307         }
 308         function implicitGroupby() {
 309                 return false;
 310         }
 311         function implicitOrderby() {
 312                 return false;
 313         }
 314         function searchableIPs() {
 315                 return true;
 316         }
 317         function functionalIndexes() {
 318                 return true;
 319         }
 320
 321         function hasConstraint( $name ) {
 322                 $SQL = "SELECT 1 FROM pg_catalog.pg_constraint c, pg_catalog.pg_namespace n WHERE c.connamespace = n.oid AND conname = '" .
 323                                 pg_escape_string( $this->mConn, $name ) . "' AND n.nspname = '" . pg_escape_string( $this->mConn, $this->getCoreSchema() ) ."'";
 324                 $res = $this->doQuery( $SQL );
 325                 return $this->numRows( $res );
 326         }
 327
 328         /**
 329          * Usually aborts on failure
 330          * @param string $server
 331          * @param string $user
 332          * @param string $password
 333          * @param string $dbName
 334          * @throws DBConnectionError
 335          * @return DatabaseBase|null
 336          */
 337         function open( $server, $user, $password, $dbName ) {
 338                 # Test for Postgres support, to avoid suppressed fatal error
 339                 if ( !function_exists( 'pg_connect' ) ) {
 340                         throw new DBConnectionError( $this, "Postgres functions missing, have you compiled PHP with the --with-pgsql option?\n (Note: if you recently installed PHP, you may need to restart your webserver and database)\n" );
 341                 }
 342
 343                 global $wgDBport;
 344
 345                 if ( !strlen( $user ) ) { # e.g. the class is being loaded
 346                         return;
 347                 }
 348
 349                 $this->mServer = $server;
 350                 $port = $wgDBport;
 351                 $this->mUser = $user;
 352                 $this->mPassword = $password;
 353                 $this->mDBname = $dbName;
 354
 355                 $connectVars = array(
 356                         'dbname' => $dbName,
 357                         'user' => $user,
 358                         'password' => $password
 359                 );
 360                 if ( $server != false && $server != '' ) {
 361                         $connectVars['host'] = $server;
 362                 }
 363                 if ( $port != false && $port != '' ) {
 364                         $connectVars['port'] = $port;
 365                 }
 366                 if ( $this->mFlags & DBO_SSL ) {
 367                         $connectVars['sslmode'] = 1;
 368                 }
 369
 370                 $this->connectString = $this->makeConnectionString( $connectVars, PGSQL_CONNECT_FORCE_NEW );
 371                 $this->close();
 372                 $this->installErrorHandler();
 373                 $this->mConn = pg_connect( $this->connectString );
 374                 $phpError = $this->restoreErrorHandler();
 375
 376                 if ( !$this->mConn ) {
 377                         wfDebug( "DB connection error\n" );
 378                         wfDebug( "Server: $server, Database: $dbName, User: $user, Password: " . substr( $password, 0, 3 ) . "...\n" );
 379                         wfDebug( $this->lastError() . "\n" );
 380                         throw new DBConnectionError( $this, str_replace( "\n", ' ', $phpError ) );
 381                 }
 382
 383                 $this->mOpened = true;
 384                 $this->mTransactionState = new PostgresTransactionState( $this->mConn );
 385
 386                 global $wgCommandLineMode;
 387                 # If called from the command-line (e.g. importDump), only show errors
 388                 if ( $wgCommandLineMode ) {
 389                         $this->doQuery( "SET client_min_messages = 'ERROR'" );
 390                 }
 391
 392                 $this->query( "SET client_encoding='UTF8'", __METHOD__ );
 393                 $this->query( "SET datestyle = 'ISO, YMD'", __METHOD__ );
 394                 $this->query( "SET timezone = 'GMT'", __METHOD__ );
 395                 $this->query( "SET standard_conforming_strings = on", __METHOD__ );
 396                 if ( $this->getServerVersion() >= 9.0 ) {
 397                         $this->query( "SET bytea_output = 'escape'", __METHOD__ ); // PHP bug 53127
 398                 }
 399
 400                 global $wgDBmwschema;
 401                 $this->determineCoreSchema( $wgDBmwschema );
 402
 403                 return $this->mConn;
 404         }
 405
 406         /**
 407          * Postgres doesn't support selectDB in the same way MySQL does. So if the
 408          * DB name doesn't match the open connection, open a new one
 409          * @return
 410          */
 411         function selectDB( $db ) {
 412                 if ( $this->mDBname !== $db ) {
 413                         return (bool)$this->open( $this->mServer, $this->mUser, $this->mPassword, $db );
 414                 } else {
 415                         return true;
 416                 }
 417         }
 418
 419         function makeConnectionString( $vars ) {
 420                 $s = '';
 421                 foreach ( $vars as $name => $value ) {
 422                         $s .= "$name='" . str_replace( "'", "\\'", $value ) . "' ";
 423                 }
 424                 return $s;
 425         }
 426
 427         /**
 428          * Closes a database connection, if it is open
 429          * Returns success, true if already closed
 430          * @return bool
 431          */
 432         protected function closeConnection() {
 433                 return pg_close( $this->mConn );
 434         }
 435
 436         public function doQuery( $sql ) {
 437                 if ( function_exists( 'mb_convert_encoding' ) ) {
 438                         $sql = mb_convert_encoding( $sql, 'UTF-8' );
 439                 }
 440                 $this->mTransactionState->check();
 441                 if( pg_send_query( $this->mConn, $sql ) === false ) {
 442                         throw new DBUnexpectedError( $this, "Unable to post new query to PostgreSQL\n" );
 443                 }
 444                 $this->mLastResult = pg_get_result( $this->mConn );
 445                 $this->mTransactionState->check();
 446                 $this->mAffectedRows = null;
 447                 if ( pg_result_error( $this->mLastResult ) ) {
 448                         return false;
 449                 }
 450                 return $this->mLastResult;
 451         }
 452
 453         protected function dumpError () {
 454                 $diags = array( PGSQL_DIAG_SEVERITY,
 455                                 PGSQL_DIAG_SQLSTATE,
 456                                 PGSQL_DIAG_MESSAGE_PRIMARY,
 457                                 PGSQL_DIAG_MESSAGE_DETAIL,
 458                                 PGSQL_DIAG_MESSAGE_HINT,
 459                                 PGSQL_DIAG_STATEMENT_POSITION,
 460                                 PGSQL_DIAG_INTERNAL_POSITION,
 461                                 PGSQL_DIAG_INTERNAL_QUERY,
 462                                 PGSQL_DIAG_CONTEXT,
 463                                 PGSQL_DIAG_SOURCE_FILE,
 464                                 PGSQL_DIAG_SOURCE_LINE,
 465                                 PGSQL_DIAG_SOURCE_FUNCTION );
 466                 foreach ( $diags as $d ) {
 467                         wfDebug( sprintf("PgSQL ERROR(%d): %s\n", $d, pg_result_error_field( $this->mLastResult, $d ) ) );
 468                 }
 469         }
 470
 471         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 472                 /* Transaction stays in the ERROR state until rolledback */
 473                 if ( $tempIgnore ) {
 474                         /* Check for constraint violation */
 475                         if ( $errno === '23505' ) {
 476                                 parent::reportQueryError( $error, $errno, $sql, $fname, $tempIgnore );
 477                                 return;
 478                         }
 479                 }
 480                 /* Don't ignore serious errors */
 481                 $this->rollback( __METHOD__ );
 482                 parent::reportQueryError( $error, $errno, $sql, $fname, false );
 483         }
 484
 485         function queryIgnore( $sql, $fname = 'DatabasePostgres::queryIgnore' ) {
 486                 return $this->query( $sql, $fname, true );
 487         }
 488
 489         function freeResult( $res ) {
 490                 if ( $res instanceof ResultWrapper ) {
 491                         $res = $res->result;
 492                 }
 493                 wfSuppressWarnings();
 494                 $ok = pg_free_result( $res );
 495                 wfRestoreWarnings();
 496                 if ( !$ok ) {
 497                         throw new DBUnexpectedError( $this, "Unable to free Postgres result\n" );
 498                 }
 499         }
 500
 501         function fetchObject( $res ) {
 502                 if ( $res instanceof ResultWrapper ) {
 503                         $res = $res->result;
 504                 }
 505                 wfSuppressWarnings();
 506                 $row = pg_fetch_object( $res );
 507                 wfRestoreWarnings();
 508                 # @todo FIXME: HACK HACK HACK HACK debug
 509
 510                 # @todo hashar: not sure if the following test really trigger if the object
 511                 #          fetching failed.
 512                 if( pg_last_error( $this->mConn ) ) {
 513                         throw new DBUnexpectedError( $this, 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) ) );
 514                 }
 515                 return $row;
 516         }
 517
 518         function fetchRow( $res ) {
 519                 if ( $res instanceof ResultWrapper ) {
 520                         $res = $res->result;
 521                 }
 522                 wfSuppressWarnings();
 523                 $row = pg_fetch_array( $res );
 524                 wfRestoreWarnings();
 525                 if( pg_last_error( $this->mConn ) ) {
 526                         throw new DBUnexpectedError( $this, 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) ) );
 527                 }
 528                 return $row;
 529         }
 530
 531         function numRows( $res ) {
 532                 if ( $res instanceof ResultWrapper ) {
 533                         $res = $res->result;
 534                 }
 535                 wfSuppressWarnings();
 536                 $n = pg_num_rows( $res );
 537                 wfRestoreWarnings();
 538                 if( pg_last_error( $this->mConn ) ) {
 539                         throw new DBUnexpectedError( $this, 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) ) );
 540                 }
 541                 return $n;
 542         }
 543
 544         function numFields( $res ) {
 545                 if ( $res instanceof ResultWrapper ) {
 546                         $res = $res->result;
 547                 }
 548                 return pg_num_fields( $res );
 549         }
 550
 551         function fieldName( $res, $n ) {
 552                 if ( $res instanceof ResultWrapper ) {
 553                         $res = $res->result;
 554                 }
 555                 return pg_field_name( $res, $n );
 556         }
 557
 558         /**
 559          * This must be called after nextSequenceVal
 560          * @return null
 561          */
 562         function insertId() {
 563                 return $this->mInsertId;
 564         }
 565
 566         function dataSeek( $res, $row ) {
 567                 if ( $res instanceof ResultWrapper ) {
 568                         $res = $res->result;
 569                 }
 570                 return pg_result_seek( $res, $row );
 571         }
 572
 573         function lastError() {
 574                 if ( $this->mConn ) {
 575                         if ( $this->mLastResult ) {
 576                                 return pg_result_error( $this->mLastResult );
 577                         } else {
 578                                 return pg_last_error();
 579                         }
 580                 } else {
 581                         return 'No database connection';
 582                 }
 583         }
 584         function lastErrno() {
 585                 if ( $this->mLastResult ) {
 586                         return pg_result_error_field( $this->mLastResult, PGSQL_DIAG_SQLSTATE );
 587                 } else {
 588                         return false;
 589                 }
 590         }
 591
 592         function affectedRows() {
 593                 if ( !is_null( $this->mAffectedRows ) ) {
 594                         // Forced result for simulated queries
 595                         return $this->mAffectedRows;
 596                 }
 597                 if( empty( $this->mLastResult ) ) {
 598                         return 0;
 599                 }
 600                 return pg_affected_rows( $this->mLastResult );
 601         }
 602
 603         /**
 604          * Estimate rows in dataset
 605          * Returns estimated count, based on EXPLAIN output
 606          * This is not necessarily an accurate estimate, so use sparingly
 607          * Returns -1 if count cannot be found
 608          * Takes same arguments as Database::select()
 609          * @return int
 610          */
 611         function estimateRowCount( $table, $vars = '*', $conds = '', $fname = 'DatabasePostgres::estimateRowCount', $options = array() ) {
 612                 $options['EXPLAIN'] = true;
 613                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 614                 $rows = -1;
 615                 if ( $res ) {
 616                         $row = $this->fetchRow( $res );
 617                         $count = array();
 618                         if( preg_match( '/rows=(\d+)/', $row[0], $count ) ) {
 619                                 $rows = $count[1];
 620                         }
 621                 }
 622                 return $rows;
 623         }
 624
 625         /**
 626          * Returns information about an index
 627          * If errors are explicitly ignored, returns NULL on failure
 628          * @return bool|null
 629          */
 630         function indexInfo( $table, $index, $fname = 'DatabasePostgres::indexInfo' ) {
 631                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='$table'";
 632                 $res = $this->query( $sql, $fname );
 633                 if ( !$res ) {
 634                         return null;
 635                 }
 636                 foreach ( $res as $row ) {
 637                         if ( $row->indexname == $this->indexName( $index ) ) {
 638                                 return $row;
 639                         }
 640                 }
 641                 return false;
 642         }
 643
 644         /**
 645          * Returns is of attributes used in index
 646          *
 647          * @since 1.19
 648          * @return Array
 649          */
 650         function indexAttributes ( $index, $schema = false ) {
 651                 if ( $schema === false )
 652                         $schema = $this->getCoreSchema();
 653                 /*
 654                  * A subquery would be not needed if we didn't care about the order
 655                  * of attributes, but we do
 656                  */
 657                 $sql = <<<__INDEXATTR__
 658
 659                         SELECT opcname,
 660                                 attname,
 661                                 i.indoption[s.g] as option,
 662                                 pg_am.amname
 663                         FROM
 664                                 (SELECT generate_series(array_lower(isub.indkey,1), array_upper(isub.indkey,1)) AS g
 665                                         FROM
 666                                                 pg_index isub
 667                                         JOIN pg_class cis
 668                                                 ON cis.oid=isub.indexrelid
 669                                         JOIN pg_namespace ns
 670                                                 ON cis.relnamespace = ns.oid
 671                                         WHERE cis.relname='$index' AND ns.nspname='$schema') AS s,
 672                                 pg_attribute,
 673                                 pg_opclass opcls,
 674                                 pg_am,
 675                                 pg_class ci
 676                                 JOIN pg_index i
 677                                         ON ci.oid=i.indexrelid
 678                                 JOIN pg_class ct
 679                                         ON ct.oid = i.indrelid
 680                                 JOIN pg_namespace n
 681                                         ON ci.relnamespace = n.oid
 682                                 WHERE
 683                                         ci.relname='$index' AND n.nspname='$schema'
 684                                         AND     attrelid = ct.oid
 685                                         AND     i.indkey[s.g] = attnum
 686                                         AND     i.indclass[s.g] = opcls.oid
 687                                         AND     pg_am.oid = opcls.opcmethod
 688 __INDEXATTR__;
 689                 $res = $this->query( $sql, __METHOD__ );
 690                 $a = array();
 691                 if ( $res ) {
 692                         foreach ( $res as $row ) {
 693                                 $a[] = array(
 694                                         $row->attname,
 695                                         $row->opcname,
 696                                         $row->amname,
 697                                         $row->option );
 698                         }
 699                 } else {
 700                         return null;
 701                 }
 702                 return $a;
 703         }
 704
 705         function indexUnique( $table, $index, $fname = 'DatabasePostgres::indexUnique' ) {
 706                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='{$table}'".
 707                         " AND indexdef LIKE 'CREATE UNIQUE%(" .
 708                         $this->strencode( $this->indexName( $index ) ) .
 709                         ")'";
 710                 $res = $this->query( $sql, $fname );
 711                 if ( !$res ) {
 712                         return null;
 713                 }
 714                 foreach ( $res as $row ) {
 715                         return true;
 716                 }
 717                 return false;
 718         }
 719
 720         /**
 721          * INSERT wrapper, inserts an array into a table
 722          *
 723          * $args may be a single associative array, or an array of these with numeric keys,
 724          * for multi-row insert (Postgres version 8.2 and above only).
 725          *
 726          * @param $table   String: Name of the table to insert to.
 727          * @param $args    Array: Items to insert into the table.
 728          * @param $fname   String: Name of the function, for profiling
 729          * @param $options String or Array. Valid options: IGNORE
 730          *
 731          * @return bool Success of insert operation. IGNORE always returns true.
 732          */
 733         function insert( $table, $args, $fname = 'DatabasePostgres::insert', $options = array() ) {
 734                 if ( !count( $args ) ) {
 735                         return true;
 736                 }
 737
 738                 $table = $this->tableName( $table );
 739                 if ( !isset( $this->numeric_version ) ) {
 740                         $this->getServerVersion();
 741                 }
 742
 743                 if ( !is_array( $options ) ) {
 744                         $options = array( $options );
 745                 }
 746
 747                 if ( isset( $args[0] ) && is_array( $args[0] ) ) {
 748                         $multi = true;
 749                         $keys = array_keys( $args[0] );
 750                 } else {
 751                         $multi = false;
 752                         $keys = array_keys( $args );
 753                 }
 754
 755                 // If IGNORE is set, we use savepoints to emulate mysql's behavior
 756                 $savepoint = null;
 757                 if ( in_array( 'IGNORE', $options ) ) {
 758                         $savepoint = new SavepointPostgres( $this, 'mw' );
 759                         $olde = error_reporting( 0 );
 760                         // For future use, we may want to track the number of actual inserts
 761                         // Right now, insert (all writes) simply return true/false
 762                         $numrowsinserted = 0;
 763                 }
 764
 765                 $sql = "INSERT INTO $table (" . implode( ',', $keys ) . ') VALUES ';
 766
 767                 if ( $multi ) {
 768                         if ( $this->numeric_version >= 8.2 && !$savepoint ) {
 769                                 $first = true;
 770                                 foreach ( $args as $row ) {
 771                                         if ( $first ) {
 772                                                 $first = false;
 773                                         } else {
 774                                                 $sql .= ',';
 775                                         }
 776                                         $sql .= '(' . $this->makeList( $row ) . ')';
 777                                 }
 778                                 $res = (bool)$this->query( $sql, $fname, $savepoint );
 779                         } else {
 780                                 $res = true;
 781                                 $origsql = $sql;
 782                                 foreach ( $args as $row ) {
 783                                         $tempsql = $origsql;
 784                                         $tempsql .= '(' . $this->makeList( $row ) . ')';
 785
 786                                         if ( $savepoint ) {
 787                                                 $savepoint->savepoint();
 788                                         }
 789
 790                                         $tempres = (bool)$this->query( $tempsql, $fname, $savepoint );
 791
 792                                         if ( $savepoint ) {
 793                                                 $bar = pg_last_error();
 794                                                 if ( $bar != false ) {
 795                                                         $savepoint->rollback();
 796                                                 } else {
 797                                                         $savepoint->release();
 798                                                         $numrowsinserted++;
 799                                                 }
 800                                         }
 801
 802                                         // If any of them fail, we fail overall for this function call
 803                                         // Note that this will be ignored if IGNORE is set
 804                                         if ( !$tempres ) {
 805                                                 $res = false;
 806                                         }
 807                                 }
 808                         }
 809                 } else {
 810                         // Not multi, just a lone insert
 811                         if ( $savepoint ) {
 812                                 $savepoint->savepoint();
 813                         }
 814
 815                         $sql .= '(' . $this->makeList( $args ) . ')';
 816                         $res = (bool)$this->query( $sql, $fname, $savepoint );
 817                         if ( $savepoint ) {
 818                                 $bar = pg_last_error();
 819                                 if ( $bar != false ) {
 820                                         $savepoint->rollback();
 821                                 } else {
 822                                         $savepoint->release();
 823                                         $numrowsinserted++;
 824                                 }
 825                         }
 826                 }
 827                 if ( $savepoint ) {
 828                         $olde = error_reporting( $olde );
 829                         $savepoint->commit();
 830
 831                         // Set the affected row count for the whole operation
 832                         $this->mAffectedRows = $numrowsinserted;
 833
 834                         // IGNORE always returns true
 835                         return true;
 836                 }
 837
 838                 return $res;
 839         }
 840
 841         /**
 842          * INSERT SELECT wrapper
 843          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
 844          * Source items may be literals rather then field names, but strings should be quoted with Database::addQuotes()
 845          * $conds may be "*" to copy the whole table
 846          * srcTable may be an array of tables.
 847          * @todo FIXME: Implement this a little better (seperate select/insert)?
 848          * @return bool
 849          */
 850         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'DatabasePostgres::insertSelect',
 851                 $insertOptions = array(), $selectOptions = array() )
 852         {
 853                 $destTable = $this->tableName( $destTable );
 854
 855                 if( !is_array( $insertOptions ) ) {
 856                         $insertOptions = array( $insertOptions );
 857                 }
 858
 859                 /*
 860                  * If IGNORE is set, we use savepoints to emulate mysql's behavior
 861                  * Ignore LOW PRIORITY option, since it is MySQL-specific
 862                  */
 863                 $savepoint = null;
 864                 if ( in_array( 'IGNORE', $insertOptions ) ) {
 865                         $savepoint = new SavepointPostgres( $this, 'mw' );
 866                         $olde = error_reporting( 0 );
 867                         $numrowsinserted = 0;
 868                         $savepoint->savepoint();
 869                 }
 870
 871                 if( !is_array( $selectOptions ) ) {
 872                         $selectOptions = array( $selectOptions );
 873                 }
 874                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
 875                 if( is_array( $srcTable ) ) {
 876                         $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
 877                 } else {
 878                         $srcTable = $this->tableName( $srcTable );
 879                 }
 880
 881                 $sql = "INSERT INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
 882                                 " SELECT $startOpts " . implode( ',', $varMap ) .
 883                                 " FROM $srcTable $useIndex";
 884
 885                 if ( $conds != '*' ) {
 886                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
 887                 }
 888
 889                 $sql .= " $tailOpts";
 890
 891                 $res = (bool)$this->query( $sql, $fname, $savepoint );
 892                 if( $savepoint ) {
 893                         $bar = pg_last_error();
 894                         if( $bar != false ) {
 895                                 $savepoint->rollback();
 896                         } else {
 897                                 $savepoint->release();
 898                                 $numrowsinserted++;
 899                         }
 900                         $olde = error_reporting( $olde );
 901                         $savepoint->commit();
 902
 903                         // Set the affected row count for the whole operation
 904                         $this->mAffectedRows = $numrowsinserted;
 905
 906                         // IGNORE always returns true
 907                         return true;
 908                 }
 909
 910                 return $res;
 911         }
 912
 913         function tableName( $name, $format = 'quoted' ) {
 914                 # Replace reserved words with better ones
 915                 switch( $name ) {
 916                         case 'user':
 917                                 return $this->realTableName( 'mwuser', $format );
 918                         case 'text':
 919                                 return $this->realTableName( 'pagecontent', $format );
 920                         default:
 921                                 return $this->realTableName( $name, $format );
 922                 }
 923         }
 924
 925         /* Don't cheat on installer */
 926         function realTableName( $name, $format = 'quoted' ) {
 927                 return parent::tableName( $name, $format );
 928         }
 929
 930         /**
 931          * Return the next in a sequence, save the value for retrieval via insertId()
 932          * @return null
 933          */
 934         function nextSequenceValue( $seqName ) {
 935                 $safeseq = str_replace( "'", "''", $seqName );
 936                 $res = $this->query( "SELECT nextval('$safeseq')" );
 937                 $row = $this->fetchRow( $res );
 938                 $this->mInsertId = $row[0];
 939                 return $this->mInsertId;
 940         }
 941
 942         /**
 943          * Return the current value of a sequence. Assumes it has been nextval'ed in this session.
 944          * @return
 945          */
 946         function currentSequenceValue( $seqName ) {
 947                 $safeseq = str_replace( "'", "''", $seqName );
 948                 $res = $this->query( "SELECT currval('$safeseq')" );
 949                 $row = $this->fetchRow( $res );
 950                 $currval = $row[0];
 951                 return $currval;
 952         }
 953
 954         # Returns the size of a text field, or -1 for "unlimited"
 955         function textFieldSize( $table, $field ) {
 956                 $table = $this->tableName( $table );
 957                 $sql = "SELECT t.typname as ftype,a.atttypmod as size
 958                         FROM pg_class c, pg_attribute a, pg_type t
 959                         WHERE relname='$table' AND a.attrelid=c.oid AND
 960                                 a.atttypid=t.oid and a.attname='$field'";
 961                 $res =$this->query( $sql );
 962                 $row = $this->fetchObject( $res );
 963                 if ( $row->ftype == 'varchar' ) {
 964                         $size = $row->size - 4;
 965                 } else {
 966                         $size = $row->size;
 967                 }
 968                 return $size;
 969         }
 970
 971         function limitResult( $sql, $limit, $offset = false ) {
 972                 return "$sql LIMIT $limit " . ( is_numeric( $offset ) ? " OFFSET {$offset} " : '' );
 973         }
 974
 975         function wasDeadlock() {
 976                 return $this->lastErrno() == '40P01';
 977         }
 978
 979         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabasePostgres::duplicateTableStructure' ) {
 980                 $newName = $this->addIdentifierQuotes( $newName );
 981                 $oldName = $this->addIdentifierQuotes( $oldName );
 982                 return $this->query( 'CREATE ' . ( $temporary ? 'TEMPORARY ' : '' ) . " TABLE $newName (LIKE $oldName INCLUDING DEFAULTS)", $fname );
 983         }
 984
 985         function listTables( $prefix = null, $fname = 'DatabasePostgres::listTables' ) {
 986                 $eschema = $this->addQuotes( $this->getCoreSchema() );
 987                 $result = $this->query( "SELECT tablename FROM pg_tables WHERE schemaname = $eschema", $fname );
 988                 $endArray = array();
 989
 990                 foreach( $result as $table ) {
 991                         $vars = get_object_vars( $table );
 992                         $table = array_pop( $vars );
 993                         if( !$prefix || strpos( $table, $prefix ) === 0 ) {
 994                                 $endArray[] = $table;
 995                         }
 996                 }
 997
 998                 return $endArray;
 999         }
1000
1001         function timestamp( $ts = 0 ) {
1002                 return wfTimestamp( TS_POSTGRES, $ts );
1003         }
1004
1005         /*
1006          * Posted by cc[plus]php[at]c2se[dot]com on 25-Mar-2009 09:12
1007          * to http://www.php.net/manual/en/ref.pgsql.php
1008          *
1009          * Parsing a postgres array can be a tricky problem, he's my
1010          * take on this, it handles multi-dimensional arrays plus
1011          * escaping using a nasty regexp to determine the limits of each
1012          * data-item.
1013          *
1014          * This should really be handled by PHP PostgreSQL module
1015          *
1016          * @since 1.19
1017          * @param $text   string: postgreql array returned in a text form like {a,b}
1018          * @param $output string
1019          * @param $limit  int
1020          * @param $offset int
1021          * @return string
1022          */
1023         function pg_array_parse( $text, &$output, $limit = false, $offset = 1 ) {
1024                 if( false === $limit ) {
1025                         $limit = strlen( $text )-1;
1026                         $output = array();
1027                 }
1028                 if( '{}' == $text ) {
1029                         return $output;
1030                 }
1031                 do {
1032                         if ( '{' != $text{$offset} ) {
1033                                 preg_match( "/(\\{?\"([^\"\\\\]|\\\\.)*\"|[^,{}]+)+([,}]+)/",
1034                                         $text, $match, 0, $offset );
1035                                 $offset += strlen( $match[0] );
1036                                 $output[] = ( '"' != $match[1]{0}
1037                                                 ? $match[1]
1038                                                 : stripcslashes( substr( $match[1], 1, -1 ) ) );
1039                                 if ( '},' == $match[3] ) {
1040                                         return $output;
1041                                 }
1042                         } else {
1043                                 $offset = $this->pg_array_parse( $text, $output, $limit, $offset+1 );
1044                         }
1045                 } while ( $limit > $offset );
1046                 return $output;
1047         }
1048
1049         /**
1050          * Return aggregated value function call
1051          */
1052         public function aggregateValue( $valuedata, $valuename = 'value' ) {
1053                 return $valuedata;
1054         }
1055
1056         /**
1057          * @return string wikitext of a link to the server software's web site
1058          */
1059         public static function getSoftwareLink() {
1060                 return '[http://www.postgresql.org/ PostgreSQL]';
1061         }
1062
1063         /**
1064          * Return current schema (executes SELECT current_schema())
1065          * Needs transaction
1066          *
1067          * @since 1.19
1068          * @return string return default schema for the current session
1069          */
1070         function getCurrentSchema() {
1071                 $res = $this->query( "SELECT current_schema()", __METHOD__ );
1072                 $row = $this->fetchRow( $res );
1073                 return $row[0];
1074         }
1075
1076         /**
1077          * Return list of schemas which are accessible without schema name
1078          * This is list does not contain magic keywords like "$user"
1079          * Needs transaction
1080          *
1081          * @see getSearchPath()
1082          * @see setSearchPath()
1083          * @since 1.19
1084          * @return array list of actual schemas for the current sesson
1085          */
1086         function getSchemas() {
1087                 $res = $this->query( "SELECT current_schemas(false)", __METHOD__ );
1088                 $row = $this->fetchRow( $res );
1089                 $schemas = array();
1090                 /* PHP pgsql support does not support array type, "{a,b}" string is returned */
1091                 return $this->pg_array_parse( $row[0], $schemas );
1092         }
1093
1094         /**
1095          * Return search patch for schemas
1096          * This is different from getSchemas() since it contain magic keywords
1097          * (like "$user").
1098          * Needs transaction
1099          *
1100          * @since 1.19
1101          * @return array how to search for table names schemas for the current user
1102          */
1103         function getSearchPath() {
1104                 $res = $this->query( "SHOW search_path", __METHOD__ );
1105                 $row = $this->fetchRow( $res );
1106                 /* PostgreSQL returns SHOW values as strings */
1107                 return explode( ",", $row[0] );
1108         }
1109
1110         /**
1111          * Update search_path, values should already be sanitized
1112          * Values may contain magic keywords like "$user"
1113          * @since 1.19
1114          *
1115          * @param $search_path array list of schemas to be searched by default
1116          */
1117         function setSearchPath( $search_path ) {
1118                 $this->query( "SET search_path = " . implode( ", ", $search_path ) );
1119         }
1120
1121         /**
1122          * Determine default schema for MediaWiki core
1123          * Adjust this session schema search path if desired schema exists
1124          * and is not alread there.
1125          *
1126          * We need to have name of the core schema stored to be able
1127          * to query database metadata.
1128          *
1129          * This will be also called by the installer after the schema is created
1130          *
1131          * @since 1.19
1132          * @param $desired_schema string
1133          */
1134         function determineCoreSchema( $desired_schema ) {
1135                 $this->begin( __METHOD__ );
1136                 if ( $this->schemaExists( $desired_schema ) ) {
1137                         if ( in_array( $desired_schema, $this->getSchemas() ) ) {
1138                                 $this->mCoreSchema = $desired_schema;
1139                                 wfDebug( "Schema \"" . $desired_schema . "\" already in the search path\n" );
1140                         } else {
1141                                 /**
1142                                  * Prepend our schema (e.g. 'mediawiki') in front
1143                                  * of the search path
1144                                  * Fixes bug 15816
1145                                  */
1146                                 $search_path = $this->getSearchPath();
1147                                 array_unshift( $search_path,
1148                                         $this->addIdentifierQuotes( $desired_schema ));
1149                                 $this->setSearchPath( $search_path );
1150                                 $this->mCoreSchema = $desired_schema;
1151                                 wfDebug( "Schema \"" . $desired_schema . "\" added to the search path\n" );
1152                         }
1153                 } else {
1154                         $this->mCoreSchema = $this->getCurrentSchema();
1155                         wfDebug( "Schema \"" . $desired_schema . "\" not found, using current \"" . $this->mCoreSchema . "\"\n" );
1156                 }
1157                 /* Commit SET otherwise it will be rollbacked on error or IGNORE SELECT */
1158                 $this->commit( __METHOD__ );
1159         }
1160
1161         /**
1162          * Return schema name fore core MediaWiki tables
1163          *
1164          * @since 1.19
1165          * @return string core schema name
1166          */
1167         function getCoreSchema() {
1168                 return $this->mCoreSchema;
1169         }
1170
1171         /**
1172          * @return string Version information from the database
1173          */
1174         function getServerVersion() {
1175                 if ( !isset( $this->numeric_version ) ) {
1176                         $versionInfo = pg_version( $this->mConn );
1177                         if ( version_compare( $versionInfo['client'], '7.4.0', 'lt' ) ) {
1178                                 // Old client, abort install
1179                                 $this->numeric_version = '7.3 or earlier';
1180                         } elseif ( isset( $versionInfo['server'] ) ) {
1181                                 // Normal client
1182                                 $this->numeric_version = $versionInfo['server'];
1183                         } else {
1184                                 // Bug 16937: broken pgsql extension from PHP<5.3
1185                                 $this->numeric_version = pg_parameter_status( $this->mConn, 'server_version' );
1186                         }
1187                 }
1188                 return $this->numeric_version;
1189         }
1190
1191         /**
1192          * Query whether a given relation exists (in the given schema, or the
1193          * default mw one if not given)
1194          * @return bool
1195          */
1196         function relationExists( $table, $types, $schema = false ) {
1197                 if ( !is_array( $types ) ) {
1198                         $types = array( $types );
1199                 }
1200                 if ( !$schema ) {
1201                         $schema = $this->getCoreSchema();
1202                 }
1203                 $table = $this->realTableName( $table, 'raw' );
1204                 $etable = $this->addQuotes( $table );
1205                 $eschema = $this->addQuotes( $schema );
1206                 $SQL = "SELECT 1 FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n "
1207                         . "WHERE c.relnamespace = n.oid AND c.relname = $etable AND n.nspname = $eschema "
1208                         . "AND c.relkind IN ('" . implode( "','", $types ) . "')";
1209                 $res = $this->query( $SQL );
1210                 $count = $res ? $res->numRows() : 0;
1211                 return (bool)$count;
1212         }
1213
1214         /**
1215          * For backward compatibility, this function checks both tables and
1216          * views.
1217          * @return bool
1218          */
1219         function tableExists( $table, $fname = __METHOD__, $schema = false ) {
1220                 return $this->relationExists( $table, array( 'r', 'v' ), $schema );
1221         }
1222
1223         function sequenceExists( $sequence, $schema = false ) {
1224                 return $this->relationExists( $sequence, 'S', $schema );
1225         }
1226
1227         function triggerExists( $table, $trigger ) {
1228                 $q = <<<SQL
1229         SELECT 1 FROM pg_class, pg_namespace, pg_trigger
1230                 WHERE relnamespace=pg_namespace.oid AND relkind='r'
1231                           AND tgrelid=pg_class.oid
1232                           AND nspname=%s AND relname=%s AND tgname=%s
1233 SQL;
1234                 $res = $this->query(
1235                         sprintf(
1236                                 $q,
1237                                 $this->addQuotes( $this->getCoreSchema() ),
1238                                 $this->addQuotes( $table ),
1239                                 $this->addQuotes( $trigger )
1240                         )
1241                 );
1242                 if ( !$res ) {
1243                         return null;
1244                 }
1245                 $rows = $res->numRows();
1246                 return $rows;
1247         }
1248
1249         function ruleExists( $table, $rule ) {
1250                 $exists = $this->selectField( 'pg_rules', 'rulename',
1251                         array(
1252                                 'rulename' => $rule,
1253                                 'tablename' => $table,
1254                                 'schemaname' => $this->getCoreSchema()
1255                         )
1256                 );
1257                 return $exists === $rule;
1258         }
1259
1260         function constraintExists( $table, $constraint ) {
1261                 $SQL = sprintf( "SELECT 1 FROM information_schema.table_constraints " .
1262                                 "WHERE constraint_schema = %s AND table_name = %s AND constraint_name = %s",
1263                         $this->addQuotes( $this->getCoreSchema() ),
1264                         $this->addQuotes( $table ),
1265                         $this->addQuotes( $constraint )
1266                 );
1267                 $res = $this->query( $SQL );
1268                 if ( !$res ) {
1269                         return null;
1270                 }
1271                 $rows = $res->numRows();
1272                 return $rows;
1273         }
1274
1275         /**
1276          * Query whether a given schema exists. Returns true if it does, false if it doesn't.
1277          * @return bool
1278          */
1279         function schemaExists( $schema ) {
1280                 $exists = $this->selectField( '"pg_catalog"."pg_namespace"', 1,
1281                         array( 'nspname' => $schema ), __METHOD__ );
1282                 return (bool)$exists;
1283         }
1284
1285         /**
1286          * Returns true if a given role (i.e. user) exists, false otherwise.
1287          * @return bool
1288          */
1289         function roleExists( $roleName ) {
1290                 $exists = $this->selectField( '"pg_catalog"."pg_roles"', 1,
1291                         array( 'rolname' => $roleName ), __METHOD__ );
1292                 return (bool)$exists;
1293         }
1294
1295         function fieldInfo( $table, $field ) {
1296                 return PostgresField::fromText( $this, $table, $field );
1297         }
1298
1299         /**
1300          * pg_field_type() wrapper
1301          * @return string
1302          */
1303         function fieldType( $res, $index ) {
1304                 if ( $res instanceof ResultWrapper ) {
1305                         $res = $res->result;
1306                 }
1307                 return pg_field_type( $res, $index );
1308         }
1309
1310         /**
1311          * @param $b
1312          * @return Blob
1313          */
1314         function encodeBlob( $b ) {
1315                 return new Blob( pg_escape_bytea( $this->mConn, $b ) );
1316         }
1317
1318         function decodeBlob( $b ) {
1319                 if ( $b instanceof Blob ) {
1320                         $b = $b->fetch();
1321                 }
1322                 return pg_unescape_bytea( $b );
1323         }
1324
1325         function strencode( $s ) { # Should not be called by us
1326                 return pg_escape_string( $this->mConn, $s );
1327         }
1328
1329         /**
1330          * @param $s null|bool|Blob
1331          * @return int|string
1332          */
1333         function addQuotes( $s ) {
1334                 if ( is_null( $s ) ) {
1335                         return 'NULL';
1336                 } elseif ( is_bool( $s ) ) {
1337                         return intval( $s );
1338                 } elseif ( $s instanceof Blob ) {
1339                         return "'" . $s->fetch( $s ) . "'";
1340                 }
1341                 return "'" . pg_escape_string( $this->mConn, $s ) . "'";
1342         }
1343
1344         /**
1345          * Postgres specific version of replaceVars.
1346          * Calls the parent version in Database.php
1347          *
1348          * @private
1349          *
1350          * @param $ins String: SQL string, read from a stream (usually tables.sql)
1351          *
1352          * @return string SQL string
1353          */
1354         protected function replaceVars( $ins ) {
1355                 $ins = parent::replaceVars( $ins );
1356
1357                 if ( $this->numeric_version >= 8.3 ) {
1358                         // Thanks for not providing backwards-compatibility, 8.3
1359                         $ins = preg_replace( "/to_tsvector\s*\(\s*'default'\s*,/", 'to_tsvector(', $ins );
1360                 }
1361
1362                 if ( $this->numeric_version <= 8.1 ) { // Our minimum version
1363                         $ins = str_replace( 'USING gin', 'USING gist', $ins );
1364                 }
1365
1366                 return $ins;
1367         }
1368
1369         /**
1370          * Various select options
1371          *
1372          * @private
1373          *
1374          * @param $options Array: an associative array of options to be turned into
1375          *              an SQL query, valid keys are listed in the function.
1376          * @return array
1377          */
1378         function makeSelectOptions( $options ) {
1379                 $preLimitTail = $postLimitTail = '';
1380                 $startOpts = $useIndex = '';
1381
1382                 $noKeyOptions = array();
1383                 foreach ( $options as $key => $option ) {
1384                         if ( is_numeric( $key ) ) {
1385                                 $noKeyOptions[$option] = true;
1386                         }
1387                 }
1388
1389                 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1390
1391                 $preLimitTail .= $this->makeOrderBy( $options );
1392
1393                 //if ( isset( $options['LIMIT'] ) ) {
1394                 //      $tailOpts .= $this->limitResult( '', $options['LIMIT'],
1395                 //              isset( $options['OFFSET'] ) ? $options['OFFSET']
1396                 //              : false );
1397                 //}
1398
1399                 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1400                         $postLimitTail .= ' FOR UPDATE';
1401                 }
1402                 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1403                         $startOpts .= 'DISTINCT';
1404                 }
1405
1406                 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1407         }
1408
1409         function setFakeMaster( $enabled = true ) {}
1410
1411         function getDBname() {
1412                 return $this->mDBname;
1413         }
1414
1415         function getServer() {
1416                 return $this->mServer;
1417         }
1418
1419         function buildConcat( $stringList ) {
1420                 return implode( ' || ', $stringList );
1421         }
1422
1423         public function getSearchEngine() {
1424                 return 'SearchPostgres';
1425         }
1426
1427         public function streamStatementEnd( &$sql, &$newLine ) {
1428                 # Allow dollar quoting for function declarations
1429                 if ( substr( $newLine, 0, 4 ) == '$mw$' ) {
1430                         if ( $this->delimiter ) {
1431                                 $this->delimiter = false;
1432                         }
1433                         else {
1434                                 $this->delimiter = ';';
1435                         }
1436                 }
1437                 return parent::streamStatementEnd( $sql, $newLine );
1438         }
1439
1440         /**
1441          * Check to see if a named lock is available. This is non-blocking.
1442          * See http://www.postgresql.org/docs/8.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1443          *
1444          * @param $lockName String: name of lock to poll
1445          * @param $method String: name of method calling us
1446          * @return Boolean
1447          * @since 1.20
1448          */
1449         public function lockIsFree( $lockName, $method ) {
1450                 $key = $this->addQuotes( $this->bigintFromLockName( $lockName ) );
1451                 $result = $this->query( "SELECT (CASE(pg_try_advisory_lock($key))
1452                         WHEN 'f' THEN 'f' ELSE pg_advisory_unlock($key) END) AS lockstatus", $method );
1453                 $row = $this->fetchObject( $result );
1454                 return ( $row->lockstatus === 't' );
1455         }
1456
1457         /**
1458          * See http://www.postgresql.org/docs/8.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1459          * @param $lockName string
1460          * @param $method string
1461          * @param $timeout int
1462          * @return bool
1463          */
1464         public function lock( $lockName, $method, $timeout = 5 ) {
1465                 $key = $this->addQuotes( $this->bigintFromLockName( $lockName ) );
1466                 for ( $attempts = 1; $attempts <= $timeout; ++$attempts ) {
1467                         $result = $this->query(
1468                                 "SELECT pg_try_advisory_lock($key) AS lockstatus", $method );
1469                         $row = $this->fetchObject( $result );
1470                         if ( $row->lockstatus === 't' ) {
1471                                 return true;
1472                         } else {
1473                                 sleep( 1 );
1474                         }
1475                 }
1476                 wfDebug( __METHOD__." failed to acquire lock\n" );
1477                 return false;
1478         }
1479
1480         /**
1481          * See http://www.postgresql.org/docs/8.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKSFROM PG DOCS: http://www.postgresql.org/docs/8.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1482          * @param $lockName string
1483          * @param $method string
1484          * @return bool
1485          */
1486         public function unlock( $lockName, $method ) {
1487                 $key = $this->addQuotes( $this->bigintFromLockName( $lockName ) );
1488                 $result = $this->query( "SELECT pg_advisory_unlock($key) as lockstatus", $method );
1489                 $row = $this->fetchObject( $result );
1490                 return ( $row->lockstatus === 't' );
1491         }
1492
1493         /**
1494          * @param string $lockName
1495          * @return string Integer
1496          */
1497         private function bigintFromLockName( $lockName ) {
1498                 return wfBaseConvert( substr( sha1( $lockName ), 0, 15 ), 16, 10 );
1499         }
1500 } // end DatabasePostgres class