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
  83                 return $n;
  84         }
  85
  86         function name() {
  87                 return $this->name;
  88         }
  89
  90         function tableName() {
  91                 return $this->tablename;
  92         }
  93
  94         function type() {
  95                 return $this->type;
  96         }
  97
  98         function isNullable() {
  99                 return $this->nullable;
 100         }
 101
 102         function maxLength() {
 103                 return $this->max_length;
 104         }
 105
 106         function is_deferrable() {
 107                 return $this->deferrable;
 108         }
 109
 110         function is_deferred() {
 111                 return $this->deferred;
 112         }
 113
 114         function conname() {
 115                 return $this->conname;
 116         }
 117
 118         /**
 119          * @since 1.19
 120          */
 121         function defaultValue() {
 122                 if ( $this->has_default ) {
 123                         return $this->default;
 124                 } else {
 125                         return false;
 126                 }
 127         }
 128 }
 129
 130 /**
 131  * Used to debug transaction processing
 132  * Only used if $wgDebugDBTransactions is true
 133  *
 134  * @since 1.19
 135  * @ingroup Database
 136  */
 137 class PostgresTransactionState {
 138         private 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         /** @var array */
 159         private $mNewState;
 160
 161         /** @var array */
 162         private $mCurrentState;
 163
 164         public function __construct( $conn ) {
 165                 $this->mConn = $conn;
 166                 $this->update();
 167                 $this->mCurrentState = $this->mNewState;
 168         }
 169
 170         public function update() {
 171                 $this->mNewState = array(
 172                         pg_connection_status( $this->mConn ),
 173                         pg_transaction_status( $this->mConn )
 174                 );
 175         }
 176
 177         public function check() {
 178                 global $wgDebugDBTransactions;
 179                 $this->update();
 180                 if ( $wgDebugDBTransactions ) {
 181                         if ( $this->mCurrentState !== $this->mNewState ) {
 182                                 $old = reset( $this->mCurrentState );
 183                                 $new = reset( $this->mNewState );
 184                                 foreach ( self::$WATCHED as $watched ) {
 185                                         if ( $old !== $new ) {
 186                                                 $this->log_changed( $old, $new, $watched );
 187                                         }
 188                                         $old = next( $this->mCurrentState );
 189                                         $new = next( $this->mNewState );
 190                                 }
 191                         }
 192                 }
 193                 $this->mCurrentState = $this->mNewState;
 194         }
 195
 196         protected function describe_changed( $status, $desc_table ) {
 197                 if ( isset( $desc_table[$status] ) ) {
 198                         return $desc_table[$status];
 199                 } else {
 200                         return "STATUS " . $status;
 201                 }
 202         }
 203
 204         protected function log_changed( $old, $new, $watched ) {
 205                 wfDebug( sprintf( $watched["desc"],
 206                         $this->mConn,
 207                         $this->describe_changed( $old, $watched["states"] ),
 208                         $this->describe_changed( $new, $watched["states"] )
 209                 ) );
 210         }
 211 }
 212
 213 /**
 214  * Manage savepoints within a transaction
 215  * @ingroup Database
 216  * @since 1.19
 217  */
 218 class SavepointPostgres {
 219         /**
 220          * Establish a savepoint within a transaction
 221          */
 222         protected $dbw;
 223         protected $id;
 224         protected $didbegin;
 225
 226         public function __construct( $dbw, $id ) {
 227                 $this->dbw = $dbw;
 228                 $this->id = $id;
 229                 $this->didbegin = false;
 230                 /* If we are not in a transaction, we need to be for savepoint trickery */
 231                 if ( !$dbw->trxLevel() ) {
 232                         $dbw->begin( "FOR SAVEPOINT" );
 233                         $this->didbegin = true;
 234                 }
 235         }
 236
 237         public function __destruct() {
 238                 if ( $this->didbegin ) {
 239                         $this->dbw->rollback();
 240                         $this->didbegin = false;
 241                 }
 242         }
 243
 244         public function commit() {
 245                 if ( $this->didbegin ) {
 246                         $this->dbw->commit();
 247                         $this->didbegin = false;
 248                 }
 249         }
 250
 251         protected function query( $keyword, $msg_ok, $msg_failed ) {
 252                 global $wgDebugDBTransactions;
 253                 if ( $this->dbw->doQuery( $keyword . " " . $this->id ) !== false ) {
 254                         if ( $wgDebugDBTransactions ) {
 255                                 wfDebug( sprintf( $msg_ok, $this->id ) );
 256                         }
 257                 } else {
 258                         wfDebug( sprintf( $msg_failed, $this->id ) );
 259                 }
 260         }
 261
 262         public function savepoint() {
 263                 $this->query( "SAVEPOINT",
 264                         "Transaction state: savepoint \"%s\" established.\n",
 265                         "Transaction state: establishment of savepoint \"%s\" FAILED.\n"
 266                 );
 267         }
 268
 269         public function release() {
 270                 $this->query( "RELEASE",
 271                         "Transaction state: savepoint \"%s\" released.\n",
 272                         "Transaction state: release of savepoint \"%s\" FAILED.\n"
 273                 );
 274         }
 275
 276         public function rollback() {
 277                 $this->query( "ROLLBACK TO",
 278                         "Transaction state: savepoint \"%s\" rolled back.\n",
 279                         "Transaction state: rollback of savepoint \"%s\" FAILED.\n"
 280                 );
 281         }
 282
 283         public function __toString() {
 284                 return (string)$this->id;
 285         }
 286 }
 287
 288 /**
 289  * @ingroup Database
 290  */
 291 class DatabasePostgres extends DatabaseBase {
 292         /** @var resource */
 293         protected $mLastResult = null;
 294
 295         /** @var int The number of rows affected as an integer */
 296         protected $mAffectedRows = null;
 297
 298         /** @var int */
 299         private $mInsertId = null;
 300
 301         /** @var float|string */
 302         private $numericVersion = null;
 303
 304         /** @var string Connect string to open a PostgreSQL connection */
 305         private $connectString;
 306
 307         /** @var PostgresTransactionState */
 308         private $mTransactionState;
 309
 310         /** @var string */
 311         private $mCoreSchema;
 312
 313         function getType() {
 314                 return 'postgres';
 315         }
 316
 317         function cascadingDeletes() {
 318                 return true;
 319         }
 320
 321         function cleanupTriggers() {
 322                 return true;
 323         }
 324
 325         function strictIPs() {
 326                 return true;
 327         }
 328
 329         function realTimestamps() {
 330                 return true;
 331         }
 332
 333         function implicitGroupby() {
 334                 return false;
 335         }
 336
 337         function implicitOrderby() {
 338                 return false;
 339         }
 340
 341         function searchableIPs() {
 342                 return true;
 343         }
 344
 345         function functionalIndexes() {
 346                 return true;
 347         }
 348
 349         function hasConstraint( $name ) {
 350                 $SQL = "SELECT 1 FROM pg_catalog.pg_constraint c, pg_catalog.pg_namespace n " .
 351                         "WHERE c.connamespace = n.oid AND conname = '" .
 352                         pg_escape_string( $this->mConn, $name ) . "' AND n.nspname = '" .
 353                         pg_escape_string( $this->mConn, $this->getCoreSchema() ) . "'";
 354                 $res = $this->doQuery( $SQL );
 355
 356                 return $this->numRows( $res );
 357         }
 358
 359         /**
 360          * Usually aborts on failure
 361          * @param string $server
 362          * @param string $user
 363          * @param string $password
 364          * @param string $dbName
 365          * @throws DBConnectionError
 366          * @return DatabaseBase|null
 367          */
 368         function open( $server, $user, $password, $dbName ) {
 369                 # Test for Postgres support, to avoid suppressed fatal error
 370                 if ( !function_exists( 'pg_connect' ) ) {
 371                         throw new DBConnectionError(
 372                                 $this,
 373                                 "Postgres functions missing, have you compiled PHP with the --with-pgsql\n" .
 374                                 "option? (Note: if you recently installed PHP, you may need to restart your\n" .
 375                                 "webserver and database)\n"
 376                         );
 377                 }
 378
 379                 global $wgDBport;
 380
 381                 if ( !strlen( $user ) ) { # e.g. the class is being loaded
 382                         return;
 383                 }
 384
 385                 $this->mServer = $server;
 386                 $port = $wgDBport;
 387                 $this->mUser = $user;
 388                 $this->mPassword = $password;
 389                 $this->mDBname = $dbName;
 390
 391                 $connectVars = array(
 392                         'dbname' => $dbName,
 393                         'user' => $user,
 394                         'password' => $password
 395                 );
 396                 if ( $server != false && $server != '' ) {
 397                         $connectVars['host'] = $server;
 398                 }
 399                 if ( $port != false && $port != '' ) {
 400                         $connectVars['port'] = $port;
 401                 }
 402                 if ( $this->mFlags & DBO_SSL ) {
 403                         $connectVars['sslmode'] = 1;
 404                 }
 405
 406                 $this->connectString = $this->makeConnectionString( $connectVars, PGSQL_CONNECT_FORCE_NEW );
 407                 $this->close();
 408                 $this->installErrorHandler();
 409
 410                 try {
 411                         $this->mConn = pg_connect( $this->connectString );
 412                 } catch ( Exception $ex ) {
 413                         $this->restoreErrorHandler();
 414                         throw $ex;
 415                 }
 416
 417                 $phpError = $this->restoreErrorHandler();
 418
 419                 if ( !$this->mConn ) {
 420                         wfDebug( "DB connection error\n" );
 421                         wfDebug( "Server: $server, Database: $dbName, User: $user, Password: " .
 422                                 substr( $password, 0, 3 ) . "...\n" );
 423                         wfDebug( $this->lastError() . "\n" );
 424                         throw new DBConnectionError( $this, str_replace( "\n", ' ', $phpError ) );
 425                 }
 426
 427                 $this->mOpened = true;
 428                 $this->mTransactionState = new PostgresTransactionState( $this->mConn );
 429
 430                 global $wgCommandLineMode;
 431                 # If called from the command-line (e.g. importDump), only show errors
 432                 if ( $wgCommandLineMode ) {
 433                         $this->doQuery( "SET client_min_messages = 'ERROR'" );
 434                 }
 435
 436                 $this->query( "SET client_encoding='UTF8'", __METHOD__ );
 437                 $this->query( "SET datestyle = 'ISO, YMD'", __METHOD__ );
 438                 $this->query( "SET timezone = 'GMT'", __METHOD__ );
 439                 $this->query( "SET standard_conforming_strings = on", __METHOD__ );
 440                 if ( $this->getServerVersion() >= 9.0 ) {
 441                         $this->query( "SET bytea_output = 'escape'", __METHOD__ ); // PHP bug 53127
 442                 }
 443
 444                 global $wgDBmwschema;
 445                 $this->determineCoreSchema( $wgDBmwschema );
 446
 447                 return $this->mConn;
 448         }
 449
 450         /**
 451          * Postgres doesn't support selectDB in the same way MySQL does. So if the
 452          * DB name doesn't match the open connection, open a new one
 453          * @return
 454          */
 455         function selectDB( $db ) {
 456                 if ( $this->mDBname !== $db ) {
 457                         return (bool)$this->open( $this->mServer, $this->mUser, $this->mPassword, $db );
 458                 } else {
 459                         return true;
 460                 }
 461         }
 462
 463         function makeConnectionString( $vars ) {
 464                 $s = '';
 465                 foreach ( $vars as $name => $value ) {
 466                         $s .= "$name='" . str_replace( "'", "\\'", $value ) . "' ";
 467                 }
 468
 469                 return $s;
 470         }
 471
 472         /**
 473          * Closes a database connection, if it is open
 474          * Returns success, true if already closed
 475          * @return bool
 476          */
 477         protected function closeConnection() {
 478                 return pg_close( $this->mConn );
 479         }
 480
 481         public function doQuery( $sql ) {
 482                 if ( function_exists( 'mb_convert_encoding' ) ) {
 483                         $sql = mb_convert_encoding( $sql, 'UTF-8' );
 484                 }
 485                 $this->mTransactionState->check();
 486                 if ( pg_send_query( $this->mConn, $sql ) === false ) {
 487                         throw new DBUnexpectedError( $this, "Unable to post new query to PostgreSQL\n" );
 488                 }
 489                 $this->mLastResult = pg_get_result( $this->mConn );
 490                 $this->mTransactionState->check();
 491                 $this->mAffectedRows = null;
 492                 if ( pg_result_error( $this->mLastResult ) ) {
 493                         return false;
 494                 }
 495
 496                 return $this->mLastResult;
 497         }
 498
 499         protected function dumpError() {
 500                 $diags = array(
 501                         PGSQL_DIAG_SEVERITY,
 502                         PGSQL_DIAG_SQLSTATE,
 503                         PGSQL_DIAG_MESSAGE_PRIMARY,
 504                         PGSQL_DIAG_MESSAGE_DETAIL,
 505                         PGSQL_DIAG_MESSAGE_HINT,
 506                         PGSQL_DIAG_STATEMENT_POSITION,
 507                         PGSQL_DIAG_INTERNAL_POSITION,
 508                         PGSQL_DIAG_INTERNAL_QUERY,
 509                         PGSQL_DIAG_CONTEXT,
 510                         PGSQL_DIAG_SOURCE_FILE,
 511                         PGSQL_DIAG_SOURCE_LINE,
 512                         PGSQL_DIAG_SOURCE_FUNCTION
 513                 );
 514                 foreach ( $diags as $d ) {
 515                         wfDebug( sprintf( "PgSQL ERROR(%d): %s\n",
 516                                 $d, pg_result_error_field( $this->mLastResult, $d ) ) );
 517                 }
 518         }
 519
 520         function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
 521                 /* Transaction stays in the ERROR state until rolledback */
 522                 if ( $tempIgnore ) {
 523                         /* Check for constraint violation */
 524                         if ( $errno === '23505' ) {
 525                                 parent::reportQueryError( $error, $errno, $sql, $fname, $tempIgnore );
 526
 527                                 return;
 528                         }
 529                 }
 530                 /* Don't ignore serious errors */
 531                 $this->rollback( __METHOD__ );
 532                 parent::reportQueryError( $error, $errno, $sql, $fname, false );
 533         }
 534
 535         function queryIgnore( $sql, $fname = __METHOD__ ) {
 536                 return $this->query( $sql, $fname, true );
 537         }
 538
 539         function freeResult( $res ) {
 540                 if ( $res instanceof ResultWrapper ) {
 541                         $res = $res->result;
 542                 }
 543                 wfSuppressWarnings();
 544                 $ok = pg_free_result( $res );
 545                 wfRestoreWarnings();
 546                 if ( !$ok ) {
 547                         throw new DBUnexpectedError( $this, "Unable to free Postgres result\n" );
 548                 }
 549         }
 550
 551         function fetchObject( $res ) {
 552                 if ( $res instanceof ResultWrapper ) {
 553                         $res = $res->result;
 554                 }
 555                 wfSuppressWarnings();
 556                 $row = pg_fetch_object( $res );
 557                 wfRestoreWarnings();
 558                 # @todo FIXME: HACK HACK HACK HACK debug
 559
 560                 # @todo hashar: not sure if the following test really trigger if the object
 561                 #          fetching failed.
 562                 if ( pg_last_error( $this->mConn ) ) {
 563                         throw new DBUnexpectedError(
 564                                 $this,
 565                                 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) )
 566                         );
 567                 }
 568
 569                 return $row;
 570         }
 571
 572         function fetchRow( $res ) {
 573                 if ( $res instanceof ResultWrapper ) {
 574                         $res = $res->result;
 575                 }
 576                 wfSuppressWarnings();
 577                 $row = pg_fetch_array( $res );
 578                 wfRestoreWarnings();
 579                 if ( pg_last_error( $this->mConn ) ) {
 580                         throw new DBUnexpectedError(
 581                                 $this,
 582                                 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) )
 583                         );
 584                 }
 585
 586                 return $row;
 587         }
 588
 589         function numRows( $res ) {
 590                 if ( $res instanceof ResultWrapper ) {
 591                         $res = $res->result;
 592                 }
 593                 wfSuppressWarnings();
 594                 $n = pg_num_rows( $res );
 595                 wfRestoreWarnings();
 596                 if ( pg_last_error( $this->mConn ) ) {
 597                         throw new DBUnexpectedError(
 598                                 $this,
 599                                 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) )
 600                         );
 601                 }
 602
 603                 return $n;
 604         }
 605
 606         function numFields( $res ) {
 607                 if ( $res instanceof ResultWrapper ) {
 608                         $res = $res->result;
 609                 }
 610
 611                 return pg_num_fields( $res );
 612         }
 613
 614         function fieldName( $res, $n ) {
 615                 if ( $res instanceof ResultWrapper ) {
 616                         $res = $res->result;
 617                 }
 618
 619                 return pg_field_name( $res, $n );
 620         }
 621
 622         /**
 623          * Return the result of the last call to nextSequenceValue();
 624          * This must be called after nextSequenceValue().
 625          *
 626          * @return int|null
 627          */
 628         function insertId() {
 629                 return $this->mInsertId;
 630         }
 631
 632         function dataSeek( $res, $row ) {
 633                 if ( $res instanceof ResultWrapper ) {
 634                         $res = $res->result;
 635                 }
 636
 637                 return pg_result_seek( $res, $row );
 638         }
 639
 640         function lastError() {
 641                 if ( $this->mConn ) {
 642                         if ( $this->mLastResult ) {
 643                                 return pg_result_error( $this->mLastResult );
 644                         } else {
 645                                 return pg_last_error();
 646                         }
 647                 } else {
 648                         return 'No database connection';
 649                 }
 650         }
 651
 652         function lastErrno() {
 653                 if ( $this->mLastResult ) {
 654                         return pg_result_error_field( $this->mLastResult, PGSQL_DIAG_SQLSTATE );
 655                 } else {
 656                         return false;
 657                 }
 658         }
 659
 660         function affectedRows() {
 661                 if ( !is_null( $this->mAffectedRows ) ) {
 662                         // Forced result for simulated queries
 663                         return $this->mAffectedRows;
 664                 }
 665                 if ( empty( $this->mLastResult ) ) {
 666                         return 0;
 667                 }
 668
 669                 return pg_affected_rows( $this->mLastResult );
 670         }
 671
 672         /**
 673          * Estimate rows in dataset
 674          * Returns estimated count, based on EXPLAIN output
 675          * This is not necessarily an accurate estimate, so use sparingly
 676          * Returns -1 if count cannot be found
 677          * Takes same arguments as Database::select()
 678          * @return int
 679          */
 680         function estimateRowCount( $table, $vars = '*', $conds = '',
 681                 $fname = __METHOD__, $options = array()
 682         ) {
 683                 $options['EXPLAIN'] = true;
 684                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 685                 $rows = -1;
 686                 if ( $res ) {
 687                         $row = $this->fetchRow( $res );
 688                         $count = array();
 689                         if ( preg_match( '/rows=(\d+)/', $row[0], $count ) ) {
 690                                 $rows = $count[1];
 691                         }
 692                 }
 693
 694                 return $rows;
 695         }
 696
 697         /**
 698          * Returns information about an index
 699          * If errors are explicitly ignored, returns NULL on failure
 700          * @return bool|null
 701          */
 702         function indexInfo( $table, $index, $fname = __METHOD__ ) {
 703                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='$table'";
 704                 $res = $this->query( $sql, $fname );
 705                 if ( !$res ) {
 706                         return null;
 707                 }
 708                 foreach ( $res as $row ) {
 709                         if ( $row->indexname == $this->indexName( $index ) ) {
 710                                 return $row;
 711                         }
 712                 }
 713
 714                 return false;
 715         }
 716
 717         /**
 718          * Returns is of attributes used in index
 719          *
 720          * @since 1.19
 721          * @return Array
 722          */
 723         function indexAttributes( $index, $schema = false ) {
 724                 if ( $schema === false ) {
 725                         $schema = $this->getCoreSchema();
 726                 }
 727                 /*
 728                  * A subquery would be not needed if we didn't care about the order
 729                  * of attributes, but we do
 730                  */
 731                 $sql = <<<__INDEXATTR__
 732
 733                         SELECT opcname,
 734                                 attname,
 735                                 i.indoption[s.g] as option,
 736                                 pg_am.amname
 737                         FROM
 738                                 (SELECT generate_series(array_lower(isub.indkey,1), array_upper(isub.indkey,1)) AS g
 739                                         FROM
 740                                                 pg_index isub
 741                                         JOIN pg_class cis
 742                                                 ON cis.oid=isub.indexrelid
 743                                         JOIN pg_namespace ns
 744                                                 ON cis.relnamespace = ns.oid
 745                                         WHERE cis.relname='$index' AND ns.nspname='$schema') AS s,
 746                                 pg_attribute,
 747                                 pg_opclass opcls,
 748                                 pg_am,
 749                                 pg_class ci
 750                                 JOIN pg_index i
 751                                         ON ci.oid=i.indexrelid
 752                                 JOIN pg_class ct
 753                                         ON ct.oid = i.indrelid
 754                                 JOIN pg_namespace n
 755                                         ON ci.relnamespace = n.oid
 756                                 WHERE
 757                                         ci.relname='$index' AND n.nspname='$schema'
 758                                         AND     attrelid = ct.oid
 759                                         AND     i.indkey[s.g] = attnum
 760                                         AND     i.indclass[s.g] = opcls.oid
 761                                         AND     pg_am.oid = opcls.opcmethod
 762 __INDEXATTR__;
 763                 $res = $this->query( $sql, __METHOD__ );
 764                 $a = array();
 765                 if ( $res ) {
 766                         foreach ( $res as $row ) {
 767                                 $a[] = array(
 768                                         $row->attname,
 769                                         $row->opcname,
 770                                         $row->amname,
 771                                         $row->option );
 772                         }
 773                 } else {
 774                         return null;
 775                 }
 776
 777                 return $a;
 778         }
 779
 780         function indexUnique( $table, $index, $fname = __METHOD__ ) {
 781                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='{$table}'" .
 782                         " AND indexdef LIKE 'CREATE UNIQUE%(" .
 783                         $this->strencode( $this->indexName( $index ) ) .
 784                         ")'";
 785                 $res = $this->query( $sql, $fname );
 786                 if ( !$res ) {
 787                         return null;
 788                 }
 789
 790                 return $res->numRows() > 0;
 791         }
 792
 793         /**
 794          * INSERT wrapper, inserts an array into a table
 795          *
 796          * $args may be a single associative array, or an array of these with numeric keys,
 797          * for multi-row insert (Postgres version 8.2 and above only).
 798          *
 799          * @param $table   String: Name of the table to insert to.
 800          * @param $args    Array: Items to insert into the table.
 801          * @param $fname   String: Name of the function, for profiling
 802          * @param string $options or Array. Valid options: IGNORE
 803          *
 804          * @return bool Success of insert operation. IGNORE always returns true.
 805          */
 806         function insert( $table, $args, $fname = __METHOD__, $options = array() ) {
 807                 if ( !count( $args ) ) {
 808                         return true;
 809                 }
 810
 811                 $table = $this->tableName( $table );
 812                 if ( !isset( $this->numericVersion ) ) {
 813                         $this->getServerVersion();
 814                 }
 815
 816                 if ( !is_array( $options ) ) {
 817                         $options = array( $options );
 818                 }
 819
 820                 if ( isset( $args[0] ) && is_array( $args[0] ) ) {
 821                         $multi = true;
 822                         $keys = array_keys( $args[0] );
 823                 } else {
 824                         $multi = false;
 825                         $keys = array_keys( $args );
 826                 }
 827
 828                 // If IGNORE is set, we use savepoints to emulate mysql's behavior
 829                 $savepoint = null;
 830                 if ( in_array( 'IGNORE', $options ) ) {
 831                         $savepoint = new SavepointPostgres( $this, 'mw' );
 832                         $olde = error_reporting( 0 );
 833                         // For future use, we may want to track the number of actual inserts
 834                         // Right now, insert (all writes) simply return true/false
 835                         $numrowsinserted = 0;
 836                 }
 837
 838                 $sql = "INSERT INTO $table (" . implode( ',', $keys ) . ') VALUES ';
 839
 840                 if ( $multi ) {
 841                         if ( $this->numericVersion >= 8.2 && !$savepoint ) {
 842                                 $first = true;
 843                                 foreach ( $args as $row ) {
 844                                         if ( $first ) {
 845                                                 $first = false;
 846                                         } else {
 847                                                 $sql .= ',';
 848                                         }
 849                                         $sql .= '(' . $this->makeList( $row ) . ')';
 850                                 }
 851                                 $res = (bool)$this->query( $sql, $fname, $savepoint );
 852                         } else {
 853                                 $res = true;
 854                                 $origsql = $sql;
 855                                 foreach ( $args as $row ) {
 856                                         $tempsql = $origsql;
 857                                         $tempsql .= '(' . $this->makeList( $row ) . ')';
 858
 859                                         if ( $savepoint ) {
 860                                                 $savepoint->savepoint();
 861                                         }
 862
 863                                         $tempres = (bool)$this->query( $tempsql, $fname, $savepoint );
 864
 865                                         if ( $savepoint ) {
 866                                                 $bar = pg_last_error();
 867                                                 if ( $bar != false ) {
 868                                                         $savepoint->rollback();
 869                                                 } else {
 870                                                         $savepoint->release();
 871                                                         $numrowsinserted++;
 872                                                 }
 873                                         }
 874
 875                                         // If any of them fail, we fail overall for this function call
 876                                         // Note that this will be ignored if IGNORE is set
 877                                         if ( !$tempres ) {
 878                                                 $res = false;
 879                                         }
 880                                 }
 881                         }
 882                 } else {
 883                         // Not multi, just a lone insert
 884                         if ( $savepoint ) {
 885                                 $savepoint->savepoint();
 886                         }
 887
 888                         $sql .= '(' . $this->makeList( $args ) . ')';
 889                         $res = (bool)$this->query( $sql, $fname, $savepoint );
 890                         if ( $savepoint ) {
 891                                 $bar = pg_last_error();
 892                                 if ( $bar != false ) {
 893                                         $savepoint->rollback();
 894                                 } else {
 895                                         $savepoint->release();
 896                                         $numrowsinserted++;
 897                                 }
 898                         }
 899                 }
 900                 if ( $savepoint ) {
 901                         error_reporting( $olde );
 902                         $savepoint->commit();
 903
 904                         // Set the affected row count for the whole operation
 905                         $this->mAffectedRows = $numrowsinserted;
 906
 907                         // IGNORE always returns true
 908                         return true;
 909                 }
 910
 911                 return $res;
 912         }
 913
 914         /**
 915          * INSERT SELECT wrapper
 916          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
 917          * Source items may be literals rather then field names, but strings should
 918          * be quoted with Database::addQuotes()
 919          * $conds may be "*" to copy the whole table
 920          * srcTable may be an array of tables.
 921          * @todo FIXME: Implement this a little better (seperate select/insert)?
 922          * @return bool
 923          */
 924         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = __METHOD__,
 925                 $insertOptions = array(), $selectOptions = array() ) {
 926                 $destTable = $this->tableName( $destTable );
 927
 928                 if ( !is_array( $insertOptions ) ) {
 929                         $insertOptions = array( $insertOptions );
 930                 }
 931
 932                 /*
 933                  * If IGNORE is set, we use savepoints to emulate mysql's behavior
 934                  * Ignore LOW PRIORITY option, since it is MySQL-specific
 935                  */
 936                 $savepoint = null;
 937                 if ( in_array( 'IGNORE', $insertOptions ) ) {
 938                         $savepoint = new SavepointPostgres( $this, 'mw' );
 939                         $olde = error_reporting( 0 );
 940                         $numrowsinserted = 0;
 941                         $savepoint->savepoint();
 942                 }
 943
 944                 if ( !is_array( $selectOptions ) ) {
 945                         $selectOptions = array( $selectOptions );
 946                 }
 947                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
 948                 if ( is_array( $srcTable ) ) {
 949                         $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
 950                 } else {
 951                         $srcTable = $this->tableName( $srcTable );
 952                 }
 953
 954                 $sql = "INSERT INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
 955                         " SELECT $startOpts " . implode( ',', $varMap ) .
 956                         " FROM $srcTable $useIndex";
 957
 958                 if ( $conds != '*' ) {
 959                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
 960                 }
 961
 962                 $sql .= " $tailOpts";
 963
 964                 $res = (bool)$this->query( $sql, $fname, $savepoint );
 965                 if ( $savepoint ) {
 966                         $bar = pg_last_error();
 967                         if ( $bar != false ) {
 968                                 $savepoint->rollback();
 969                         } else {
 970                                 $savepoint->release();
 971                                 $numrowsinserted++;
 972                         }
 973                         error_reporting( $olde );
 974                         $savepoint->commit();
 975
 976                         // Set the affected row count for the whole operation
 977                         $this->mAffectedRows = $numrowsinserted;
 978
 979                         // IGNORE always returns true
 980                         return true;
 981                 }
 982
 983                 return $res;
 984         }
 985
 986         function tableName( $name, $format = 'quoted' ) {
 987                 # Replace reserved words with better ones
 988                 switch ( $name ) {
 989                         case 'user':
 990                                 return $this->realTableName( 'mwuser', $format );
 991                         case 'text':
 992                                 return $this->realTableName( 'pagecontent', $format );
 993                         default:
 994                                 return $this->realTableName( $name, $format );
 995                 }
 996         }
 997
 998         /* Don't cheat on installer */
 999         function realTableName( $name, $format = 'quoted' ) {
1000                 return parent::tableName( $name, $format );
1001         }
1002
1003         /**
1004          * Return the next in a sequence, save the value for retrieval via insertId()
1005          *
1006          * @param string $seqName
1007          * @return int|null
1008          */
1009         function nextSequenceValue( $seqName ) {
1010                 $safeseq = str_replace( "'", "''", $seqName );
1011                 $res = $this->query( "SELECT nextval('$safeseq')" );
1012                 $row = $this->fetchRow( $res );
1013                 $this->mInsertId = $row[0];
1014
1015                 return $this->mInsertId;
1016         }
1017
1018         /**
1019          * Return the current value of a sequence. Assumes it has been nextval'ed in this session.
1020          *
1021          * @param string $seqName
1022          * @return
1023          */
1024         function currentSequenceValue( $seqName ) {
1025                 $safeseq = str_replace( "'", "''", $seqName );
1026                 $res = $this->query( "SELECT currval('$safeseq')" );
1027                 $row = $this->fetchRow( $res );
1028                 $currval = $row[0];
1029
1030                 return $currval;
1031         }
1032
1033         # Returns the size of a text field, or -1 for "unlimited"
1034         function textFieldSize( $table, $field ) {
1035                 $table = $this->tableName( $table );
1036                 $sql = "SELECT t.typname as ftype,a.atttypmod as size
1037                         FROM pg_class c, pg_attribute a, pg_type t
1038                         WHERE relname='$table' AND a.attrelid=c.oid AND
1039                                 a.atttypid=t.oid and a.attname='$field'";
1040                 $res = $this->query( $sql );
1041                 $row = $this->fetchObject( $res );
1042                 if ( $row->ftype == 'varchar' ) {
1043                         $size = $row->size - 4;
1044                 } else {
1045                         $size = $row->size;
1046                 }
1047
1048                 return $size;
1049         }
1050
1051         function limitResult( $sql, $limit, $offset = false ) {
1052                 return "$sql LIMIT $limit " . ( is_numeric( $offset ) ? " OFFSET {$offset} " : '' );
1053         }
1054
1055         function wasDeadlock() {
1056                 return $this->lastErrno() == '40P01';
1057         }
1058
1059         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = __METHOD__ ) {
1060                 $newName = $this->addIdentifierQuotes( $newName );
1061                 $oldName = $this->addIdentifierQuotes( $oldName );
1062
1063                 return $this->query( 'CREATE ' . ( $temporary ? 'TEMPORARY ' : '' ) . " TABLE $newName " .
1064                         "(LIKE $oldName INCLUDING DEFAULTS)", $fname );
1065         }
1066
1067         function listTables( $prefix = null, $fname = __METHOD__ ) {
1068                 $eschema = $this->addQuotes( $this->getCoreSchema() );
1069                 $result = $this->query( "SELECT tablename FROM pg_tables WHERE schemaname = $eschema", $fname );
1070                 $endArray = array();
1071
1072                 foreach ( $result as $table ) {
1073                         $vars = get_object_vars( $table );
1074                         $table = array_pop( $vars );
1075                         if ( !$prefix || strpos( $table, $prefix ) === 0 ) {
1076                                 $endArray[] = $table;
1077                         }
1078                 }
1079
1080                 return $endArray;
1081         }
1082
1083         function timestamp( $ts = 0 ) {
1084                 return wfTimestamp( TS_POSTGRES, $ts );
1085         }
1086
1087         /*
1088          * Posted by cc[plus]php[at]c2se[dot]com on 25-Mar-2009 09:12
1089          * to http://www.php.net/manual/en/ref.pgsql.php
1090          *
1091          * Parsing a postgres array can be a tricky problem, he's my
1092          * take on this, it handles multi-dimensional arrays plus
1093          * escaping using a nasty regexp to determine the limits of each
1094          * data-item.
1095          *
1096          * This should really be handled by PHP PostgreSQL module
1097          *
1098          * @since 1.19
1099          * @param $text   string: postgreql array returned in a text form like {a,b}
1100          * @param $output string
1101          * @param $limit  int
1102          * @param $offset int
1103          * @return string
1104          */
1105         function pg_array_parse( $text, &$output, $limit = false, $offset = 1 ) {
1106                 if ( false === $limit ) {
1107                         $limit = strlen( $text ) - 1;
1108                         $output = array();
1109                 }
1110                 if ( '{}' == $text ) {
1111                         return $output;
1112                 }
1113                 do {
1114                         if ( '{' != $text[$offset] ) {
1115                                 preg_match( "/(\\{?\"([^\"\\\\]|\\\\.)*\"|[^,{}]+)+([,}]+)/",
1116                                         $text, $match, 0, $offset );
1117                                 $offset += strlen( $match[0] );
1118                                 $output[] = ( '"' != $match[1][0]
1119                                         ? $match[1]
1120                                         : stripcslashes( substr( $match[1], 1, -1 ) ) );
1121                                 if ( '},' == $match[3] ) {
1122                                         return $output;
1123                                 }
1124                         } else {
1125                                 $offset = $this->pg_array_parse( $text, $output, $limit, $offset + 1 );
1126                         }
1127                 } while ( $limit > $offset );
1128
1129                 return $output;
1130         }
1131
1132         /**
1133          * Return aggregated value function call
1134          */
1135         public function aggregateValue( $valuedata, $valuename = 'value' ) {
1136                 return $valuedata;
1137         }
1138
1139         /**
1140          * @return string wikitext of a link to the server software's web site
1141          */
1142         public function getSoftwareLink() {
1143                 return '[http://www.postgresql.org/ PostgreSQL]';
1144         }
1145
1146         /**
1147          * Return current schema (executes SELECT current_schema())
1148          * Needs transaction
1149          *
1150          * @since 1.19
1151          * @return string Default schema for the current session
1152          */
1153         function getCurrentSchema() {
1154                 $res = $this->query( "SELECT current_schema()", __METHOD__ );
1155                 $row = $this->fetchRow( $res );
1156
1157                 return $row[0];
1158         }
1159
1160         /**
1161          * Return list of schemas which are accessible without schema name
1162          * This is list does not contain magic keywords like "$user"
1163          * Needs transaction
1164          *
1165          * @see getSearchPath()
1166          * @see setSearchPath()
1167          * @since 1.19
1168          * @return array list of actual schemas for the current sesson
1169          */
1170         function getSchemas() {
1171                 $res = $this->query( "SELECT current_schemas(false)", __METHOD__ );
1172                 $row = $this->fetchRow( $res );
1173                 $schemas = array();
1174
1175                 /* PHP pgsql support does not support array type, "{a,b}" string is returned */
1176
1177                 return $this->pg_array_parse( $row[0], $schemas );
1178         }
1179
1180         /**
1181          * Return search patch for schemas
1182          * This is different from getSchemas() since it contain magic keywords
1183          * (like "$user").
1184          * Needs transaction
1185          *
1186          * @since 1.19
1187          * @return array how to search for table names schemas for the current user
1188          */
1189         function getSearchPath() {
1190                 $res = $this->query( "SHOW search_path", __METHOD__ );
1191                 $row = $this->fetchRow( $res );
1192
1193                 /* PostgreSQL returns SHOW values as strings */
1194
1195                 return explode( ",", $row[0] );
1196         }
1197
1198         /**
1199          * Update search_path, values should already be sanitized
1200          * Values may contain magic keywords like "$user"
1201          * @since 1.19
1202          *
1203          * @param $search_path array list of schemas to be searched by default
1204          */
1205         function setSearchPath( $search_path ) {
1206                 $this->query( "SET search_path = " . implode( ", ", $search_path ) );
1207         }
1208
1209         /**
1210          * Determine default schema for MediaWiki core
1211          * Adjust this session schema search path if desired schema exists
1212          * and is not alread there.
1213          *
1214          * We need to have name of the core schema stored to be able
1215          * to query database metadata.
1216          *
1217          * This will be also called by the installer after the schema is created
1218          *
1219          * @since 1.19
1220          * @param $desired_schema string
1221          */
1222         function determineCoreSchema( $desired_schema ) {
1223                 $this->begin( __METHOD__ );
1224                 if ( $this->schemaExists( $desired_schema ) ) {
1225                         if ( in_array( $desired_schema, $this->getSchemas() ) ) {
1226                                 $this->mCoreSchema = $desired_schema;
1227                                 wfDebug( "Schema \"" . $desired_schema . "\" already in the search path\n" );
1228                         } else {
1229                                 /**
1230                                  * Prepend our schema (e.g. 'mediawiki') in front
1231                                  * of the search path
1232                                  * Fixes bug 15816
1233                                  */
1234                                 $search_path = $this->getSearchPath();
1235                                 array_unshift( $search_path,
1236                                         $this->addIdentifierQuotes( $desired_schema ) );
1237                                 $this->setSearchPath( $search_path );
1238                                 $this->mCoreSchema = $desired_schema;
1239                                 wfDebug( "Schema \"" . $desired_schema . "\" added to the search path\n" );
1240                         }
1241                 } else {
1242                         $this->mCoreSchema = $this->getCurrentSchema();
1243                         wfDebug( "Schema \"" . $desired_schema . "\" not found, using current \"" .
1244                                 $this->mCoreSchema . "\"\n" );
1245                 }
1246                 /* Commit SET otherwise it will be rollbacked on error or IGNORE SELECT */
1247                 $this->commit( __METHOD__ );
1248         }
1249
1250         /**
1251          * Return schema name fore core MediaWiki tables
1252          *
1253          * @since 1.19
1254          * @return string core schema name
1255          */
1256         function getCoreSchema() {
1257                 return $this->mCoreSchema;
1258         }
1259
1260         /**
1261          * @return string Version information from the database
1262          */
1263         function getServerVersion() {
1264                 if ( !isset( $this->numericVersion ) ) {
1265                         $versionInfo = pg_version( $this->mConn );
1266                         if ( version_compare( $versionInfo['client'], '7.4.0', 'lt' ) ) {
1267                                 // Old client, abort install
1268                                 $this->numericVersion = '7.3 or earlier';
1269                         } elseif ( isset( $versionInfo['server'] ) ) {
1270                                 // Normal client
1271                                 $this->numericVersion = $versionInfo['server'];
1272                         } else {
1273                                 // Bug 16937: broken pgsql extension from PHP<5.3
1274                                 $this->numericVersion = pg_parameter_status( $this->mConn, 'server_version' );
1275                         }
1276                 }
1277
1278                 return $this->numericVersion;
1279         }
1280
1281         /**
1282          * Query whether a given relation exists (in the given schema, or the
1283          * default mw one if not given)
1284          * @return bool
1285          */
1286         function relationExists( $table, $types, $schema = false ) {
1287                 if ( !is_array( $types ) ) {
1288                         $types = array( $types );
1289                 }
1290                 if ( !$schema ) {
1291                         $schema = $this->getCoreSchema();
1292                 }
1293                 $table = $this->realTableName( $table, 'raw' );
1294                 $etable = $this->addQuotes( $table );
1295                 $eschema = $this->addQuotes( $schema );
1296                 $SQL = "SELECT 1 FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n "
1297                         . "WHERE c.relnamespace = n.oid AND c.relname = $etable AND n.nspname = $eschema "
1298                         . "AND c.relkind IN ('" . implode( "','", $types ) . "')";
1299                 $res = $this->query( $SQL );
1300                 $count = $res ? $res->numRows() : 0;
1301
1302                 return (bool)$count;
1303         }
1304
1305         /**
1306          * For backward compatibility, this function checks both tables and
1307          * views.
1308          * @return bool
1309          */
1310         function tableExists( $table, $fname = __METHOD__, $schema = false ) {
1311                 return $this->relationExists( $table, array( 'r', 'v' ), $schema );
1312         }
1313
1314         function sequenceExists( $sequence, $schema = false ) {
1315                 return $this->relationExists( $sequence, 'S', $schema );
1316         }
1317
1318         function triggerExists( $table, $trigger ) {
1319                 $q = <<<SQL
1320         SELECT 1 FROM pg_class, pg_namespace, pg_trigger
1321                 WHERE relnamespace=pg_namespace.oid AND relkind='r'
1322                           AND tgrelid=pg_class.oid
1323                           AND nspname=%s AND relname=%s AND tgname=%s
1324 SQL;
1325                 $res = $this->query(
1326                         sprintf(
1327                                 $q,
1328                                 $this->addQuotes( $this->getCoreSchema() ),
1329                                 $this->addQuotes( $table ),
1330                                 $this->addQuotes( $trigger )
1331                         )
1332                 );
1333                 if ( !$res ) {
1334                         return null;
1335                 }
1336                 $rows = $res->numRows();
1337
1338                 return $rows;
1339         }
1340
1341         function ruleExists( $table, $rule ) {
1342                 $exists = $this->selectField( 'pg_rules', 'rulename',
1343                         array(
1344                                 'rulename' => $rule,
1345                                 'tablename' => $table,
1346                                 'schemaname' => $this->getCoreSchema()
1347                         )
1348                 );
1349
1350                 return $exists === $rule;
1351         }
1352
1353         function constraintExists( $table, $constraint ) {
1354                 $SQL = sprintf( "SELECT 1 FROM information_schema.table_constraints " .
1355                         "WHERE constraint_schema = %s AND table_name = %s AND constraint_name = %s",
1356                         $this->addQuotes( $this->getCoreSchema() ),
1357                         $this->addQuotes( $table ),
1358                         $this->addQuotes( $constraint )
1359                 );
1360                 $res = $this->query( $SQL );
1361                 if ( !$res ) {
1362                         return null;
1363                 }
1364                 $rows = $res->numRows();
1365
1366                 return $rows;
1367         }
1368
1369         /**
1370          * Query whether a given schema exists. Returns true if it does, false if it doesn't.
1371          * @return bool
1372          */
1373         function schemaExists( $schema ) {
1374                 $exists = $this->selectField( '"pg_catalog"."pg_namespace"', 1,
1375                         array( 'nspname' => $schema ), __METHOD__ );
1376
1377                 return (bool)$exists;
1378         }
1379
1380         /**
1381          * Returns true if a given role (i.e. user) exists, false otherwise.
1382          * @return bool
1383          */
1384         function roleExists( $roleName ) {
1385                 $exists = $this->selectField( '"pg_catalog"."pg_roles"', 1,
1386                         array( 'rolname' => $roleName ), __METHOD__ );
1387
1388                 return (bool)$exists;
1389         }
1390
1391         function fieldInfo( $table, $field ) {
1392                 return PostgresField::fromText( $this, $table, $field );
1393         }
1394
1395         /**
1396          * pg_field_type() wrapper
1397          * @return string
1398          */
1399         function fieldType( $res, $index ) {
1400                 if ( $res instanceof ResultWrapper ) {
1401                         $res = $res->result;
1402                 }
1403
1404                 return pg_field_type( $res, $index );
1405         }
1406
1407         /**
1408          * @param $b
1409          * @return Blob
1410          */
1411         function encodeBlob( $b ) {
1412                 return new Blob( pg_escape_bytea( $this->mConn, $b ) );
1413         }
1414
1415         function decodeBlob( $b ) {
1416                 if ( $b instanceof Blob ) {
1417                         $b = $b->fetch();
1418                 }
1419
1420                 return pg_unescape_bytea( $b );
1421         }
1422
1423         function strencode( $s ) { # Should not be called by us
1424                 return pg_escape_string( $this->mConn, $s );
1425         }
1426
1427         /**
1428          * @param $s null|bool|Blob
1429          * @return int|string
1430          */
1431         function addQuotes( $s ) {
1432                 if ( is_null( $s ) ) {
1433                         return 'NULL';
1434                 } elseif ( is_bool( $s ) ) {
1435                         return intval( $s );
1436                 } elseif ( $s instanceof Blob ) {
1437                         return "'" . $s->fetch( $s ) . "'";
1438                 }
1439
1440                 return "'" . pg_escape_string( $this->mConn, $s ) . "'";
1441         }
1442
1443         /**
1444          * Postgres specific version of replaceVars.
1445          * Calls the parent version in Database.php
1446          *
1447          * @private
1448          *
1449          * @param string $ins SQL string, read from a stream (usually tables.sql)
1450          *
1451          * @return string SQL string
1452          */
1453         protected function replaceVars( $ins ) {
1454                 $ins = parent::replaceVars( $ins );
1455
1456                 if ( $this->numericVersion >= 8.3 ) {
1457                         // Thanks for not providing backwards-compatibility, 8.3
1458                         $ins = preg_replace( "/to_tsvector\s*\(\s*'default'\s*,/", 'to_tsvector(', $ins );
1459                 }
1460
1461                 if ( $this->numericVersion <= 8.1 ) { // Our minimum version
1462                         $ins = str_replace( 'USING gin', 'USING gist', $ins );
1463                 }
1464
1465                 return $ins;
1466         }
1467
1468         /**
1469          * Various select options
1470          *
1471          * @private
1472          *
1473          * @param array $options an associative array of options to be turned into
1474          *              an SQL query, valid keys are listed in the function.
1475          * @return array
1476          */
1477         function makeSelectOptions( $options ) {
1478                 $preLimitTail = $postLimitTail = '';
1479                 $startOpts = $useIndex = '';
1480
1481                 $noKeyOptions = array();
1482                 foreach ( $options as $key => $option ) {
1483                         if ( is_numeric( $key ) ) {
1484                                 $noKeyOptions[$option] = true;
1485                         }
1486                 }
1487
1488                 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1489
1490                 $preLimitTail .= $this->makeOrderBy( $options );
1491
1492                 //if ( isset( $options['LIMIT'] ) ) {
1493                 //      $tailOpts .= $this->limitResult( '', $options['LIMIT'],
1494                 //              isset( $options['OFFSET'] ) ? $options['OFFSET']
1495                 //              : false );
1496                 //}
1497
1498                 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1499                         $postLimitTail .= ' FOR UPDATE';
1500                 }
1501                 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1502                         $startOpts .= 'DISTINCT';
1503                 }
1504
1505                 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
1506         }
1507
1508         function setFakeMaster( $enabled = true ) {
1509         }
1510
1511         function getDBname() {
1512                 return $this->mDBname;
1513         }
1514
1515         function getServer() {
1516                 return $this->mServer;
1517         }
1518
1519         function buildConcat( $stringList ) {
1520                 return implode( ' || ', $stringList );
1521         }
1522
1523         public function buildGroupConcatField(
1524                 $delimiter, $table, $field, $conds = '', $options = array(), $join_conds = array()
1525         ) {
1526                 $fld = "array_to_string(array_agg($field)," . $this->addQuotes( $delimiter ) . ')';
1527
1528                 return '(' . $this->selectSQLText( $table, $fld, $conds, null, array(), $join_conds ) . ')';
1529         }
1530
1531         public function getSearchEngine() {
1532                 return 'SearchPostgres';
1533         }
1534
1535         public function streamStatementEnd( &$sql, &$newLine ) {
1536                 # Allow dollar quoting for function declarations
1537                 if ( substr( $newLine, 0, 4 ) == '$mw$' ) {
1538                         if ( $this->delimiter ) {
1539                                 $this->delimiter = false;
1540                         } else {
1541                                 $this->delimiter = ';';
1542                         }
1543                 }
1544
1545                 return parent::streamStatementEnd( $sql, $newLine );
1546         }
1547
1548         /**
1549          * Check to see if a named lock is available. This is non-blocking.
1550          * See http://www.postgresql.org/docs/8.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1551          *
1552          * @param string $lockName name of lock to poll
1553          * @param string $method name of method calling us
1554          * @return Boolean
1555          * @since 1.20
1556          */
1557         public function lockIsFree( $lockName, $method ) {
1558                 $key = $this->addQuotes( $this->bigintFromLockName( $lockName ) );
1559                 $result = $this->query( "SELECT (CASE(pg_try_advisory_lock($key))
1560                         WHEN 'f' THEN 'f' ELSE pg_advisory_unlock($key) END) AS lockstatus", $method );
1561                 $row = $this->fetchObject( $result );
1562
1563                 return ( $row->lockstatus === 't' );
1564         }
1565
1566         /**
1567          * See http://www.postgresql.org/docs/8.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1568          * @param $lockName string
1569          * @param $method string
1570          * @param $timeout int
1571          * @return bool
1572          */
1573         public function lock( $lockName, $method, $timeout = 5 ) {
1574                 $key = $this->addQuotes( $this->bigintFromLockName( $lockName ) );
1575                 for ( $attempts = 1; $attempts <= $timeout; ++$attempts ) {
1576                         $result = $this->query(
1577                                 "SELECT pg_try_advisory_lock($key) AS lockstatus", $method );
1578                         $row = $this->fetchObject( $result );
1579                         if ( $row->lockstatus === 't' ) {
1580                                 return true;
1581                         } else {
1582                                 sleep( 1 );
1583                         }
1584                 }
1585                 wfDebug( __METHOD__ . " failed to acquire lock\n" );
1586
1587                 return false;
1588         }
1589
1590         /**
1591          * See http://www.postgresql.org/docs/8.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKSFROM
1592          * PG DOCS: http://www.postgresql.org/docs/8.2/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1593          * @param $lockName string
1594          * @param $method string
1595          * @return bool
1596          */
1597         public function unlock( $lockName, $method ) {
1598                 $key = $this->addQuotes( $this->bigintFromLockName( $lockName ) );
1599                 $result = $this->query( "SELECT pg_advisory_unlock($key) as lockstatus", $method );
1600                 $row = $this->fetchObject( $result );
1601
1602                 return ( $row->lockstatus === 't' );
1603         }
1604
1605         /**
1606          * @param string $lockName
1607          * @return string Integer
1608          */
1609         private function bigintFromLockName( $lockName ) {
1610                 return wfBaseConvert( substr( sha1( $lockName ), 0, 15 ), 16, 10 );
1611         }
1612 } // end DatabasePostgres class