includes/db/DatabasePostgres.php

   1 <?php
   2 /**
   3  * This is the Postgres database abstraction layer.
   4  *
   5  * @file
   6  * @ingroup Database
   7  */
   8
   9 class PostgresField implements Field {
  10         private $name, $tablename, $type, $nullable, $max_length, $deferred, $deferrable, $conname;
  11
  12         /**
  13          * @param $db DatabaseBase
  14          * @param  $table
  15          * @param  $field
  16          * @return null|PostgresField
  17          */
  18         static function fromText( $db, $table, $field ) {
  19                 global $wgDBmwschema;
  20
  21                 $q = <<<SQL
  22 SELECT
  23  attnotnull, attlen, COALESCE(conname, '') AS conname,
  24  COALESCE(condeferred, 'f') AS deferred,
  25  COALESCE(condeferrable, 'f') AS deferrable,
  26  CASE WHEN typname = 'int2' THEN 'smallint'
  27   WHEN typname = 'int4' THEN 'integer'
  28   WHEN typname = 'int8' THEN 'bigint'
  29   WHEN typname = 'bpchar' THEN 'char'
  30  ELSE typname END AS typname
  31 FROM pg_class c
  32 JOIN pg_namespace n ON (n.oid = c.relnamespace)
  33 JOIN pg_attribute a ON (a.attrelid = c.oid)
  34 JOIN pg_type t ON (t.oid = a.atttypid)
  35 LEFT JOIN pg_constraint o ON (o.conrelid = c.oid AND a.attnum = ANY(o.conkey) AND o.contype = 'f')
  36 WHERE relkind = 'r'
  37 AND nspname=%s
  38 AND relname=%s
  39 AND attname=%s;
  40 SQL;
  41
  42                 $table = $db->tableName( $table, 'raw' );
  43                 $res = $db->query(
  44                         sprintf( $q,
  45                                 $db->addQuotes( $wgDBmwschema ),
  46                                 $db->addQuotes( $table ),
  47                                 $db->addQuotes( $field )
  48                         )
  49                 );
  50                 $row = $db->fetchObject( $res );
  51                 if ( !$row ) {
  52                         return null;
  53                 }
  54                 $n = new PostgresField;
  55                 $n->type = $row->typname;
  56                 $n->nullable = ( $row->attnotnull == 'f' );
  57                 $n->name = $field;
  58                 $n->tablename = $table;
  59                 $n->max_length = $row->attlen;
  60                 $n->deferrable = ( $row->deferrable == 't' );
  61                 $n->deferred = ( $row->deferred == 't' );
  62                 $n->conname = $row->conname;
  63                 return $n;
  64         }
  65
  66         function name() {
  67                 return $this->name;
  68         }
  69
  70         function tableName() {
  71                 return $this->tablename;
  72         }
  73
  74         function type() {
  75                 return $this->type;
  76         }
  77
  78         function isNullable() {
  79                 return $this->nullable;
  80         }
  81
  82         function maxLength() {
  83                 return $this->max_length;
  84         }
  85
  86         function is_deferrable() {
  87                 return $this->deferrable;
  88         }
  89
  90         function is_deferred() {
  91                 return $this->deferred;
  92         }
  93
  94         function conname() {
  95                 return $this->conname;
  96         }
  97
  98 }
  99
 100 /**
 101  * @ingroup Database
 102  */
 103 class DatabasePostgres extends DatabaseBase {
 104         var $mInsertId = null;
 105         var $mLastResult = null;
 106         var $numeric_version = null;
 107         var $mAffectedRows = null;
 108
 109         function getType() {
 110                 return 'postgres';
 111         }
 112
 113         function cascadingDeletes() {
 114                 return true;
 115         }
 116         function cleanupTriggers() {
 117                 return true;
 118         }
 119         function strictIPs() {
 120                 return true;
 121         }
 122         function realTimestamps() {
 123                 return true;
 124         }
 125         function implicitGroupby() {
 126                 return false;
 127         }
 128         function implicitOrderby() {
 129                 return false;
 130         }
 131         function searchableIPs() {
 132                 return true;
 133         }
 134         function functionalIndexes() {
 135                 return true;
 136         }
 137
 138         function hasConstraint( $name ) {
 139                 global $wgDBmwschema;
 140                 $SQL = "SELECT 1 FROM pg_catalog.pg_constraint c, pg_catalog.pg_namespace n WHERE c.connamespace = n.oid AND conname = '" .
 141                                 pg_escape_string( $this->mConn, $name ) . "' AND n.nspname = '" . pg_escape_string( $this->mConn, $wgDBmwschema ) ."'";
 142                 $res = $this->doQuery( $SQL );
 143                 return $this->numRows( $res );
 144         }
 145
 146         /**
 147          * Usually aborts on failure
 148          * @return DatabaseBase|null
 149          */
 150         function open( $server, $user, $password, $dbName ) {
 151                 # Test for Postgres support, to avoid suppressed fatal error
 152                 if ( !function_exists( 'pg_connect' ) ) {
 153                         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" );
 154                 }
 155
 156                 global $wgDBport;
 157
 158                 if ( !strlen( $user ) ) { # e.g. the class is being loaded
 159                         return;
 160                 }
 161
 162                 $this->close();
 163                 $this->mServer = $server;
 164                 $port = $wgDBport;
 165                 $this->mUser = $user;
 166                 $this->mPassword = $password;
 167                 $this->mDBname = $dbName;
 168
 169                 $connectVars = array(
 170                         'dbname' => $dbName,
 171                         'user' => $user,
 172                         'password' => $password
 173                 );
 174                 if ( $server != false && $server != '' ) {
 175                         $connectVars['host'] = $server;
 176                 }
 177                 if ( $port != false && $port != '' ) {
 178                         $connectVars['port'] = $port;
 179                 }
 180                 $connectString = $this->makeConnectionString( $connectVars, PGSQL_CONNECT_FORCE_NEW );
 181
 182                 $this->installErrorHandler();
 183                 $this->mConn = pg_connect( $connectString );
 184                 $phpError = $this->restoreErrorHandler();
 185
 186                 if ( !$this->mConn ) {
 187                         wfDebug( "DB connection error\n" );
 188                         wfDebug( "Server: $server, Database: $dbName, User: $user, Password: " . substr( $password, 0, 3 ) . "...\n" );
 189                         wfDebug( $this->lastError() . "\n" );
 190                         throw new DBConnectionError( $this, str_replace( "\n", ' ', $phpError ) );
 191                 }
 192
 193                 $this->mOpened = true;
 194
 195                 global $wgCommandLineMode;
 196                 # If called from the command-line (e.g. importDump), only show errors
 197                 if ( $wgCommandLineMode ) {
 198                         $this->doQuery( "SET client_min_messages = 'ERROR'" );
 199                 }
 200
 201                 $this->query( "SET client_encoding='UTF8'", __METHOD__ );
 202                 $this->query( "SET datestyle = 'ISO, YMD'", __METHOD__ );
 203                 $this->query( "SET timezone = 'GMT'", __METHOD__ );
 204                 $this->query( "SET standard_conforming_strings = on", __METHOD__ );
 205
 206                 global $wgDBmwschema;
 207                 if ( $this->schemaExists( $wgDBmwschema ) ) {
 208                         $safeschema = $this->addIdentifierQuotes( $wgDBmwschema );
 209                         $this->doQuery( "SET search_path = $safeschema" );
 210                 } else {
 211                         $this->doQuery( "SET search_path = public" );
 212                 }
 213
 214                 return $this->mConn;
 215         }
 216
 217         /**
 218          * Postgres doesn't support selectDB in the same way MySQL does. So if the
 219          * DB name doesn't match the open connection, open a new one
 220          * @return
 221          */
 222         function selectDB( $db ) {
 223                 if ( $this->mDBname !== $db ) {
 224                         return (bool)$this->open( $this->mServer, $this->mUser, $this->mPassword, $db );
 225                 } else {
 226                         return true;
 227                 }
 228         }
 229
 230         function makeConnectionString( $vars ) {
 231                 $s = '';
 232                 foreach ( $vars as $name => $value ) {
 233                         $s .= "$name='" . str_replace( "'", "\\'", $value ) . "' ";
 234                 }
 235                 return $s;
 236         }
 237
 238         /**
 239          * Closes a database connection, if it is open
 240          * Returns success, true if already closed
 241          * @return bool
 242          */
 243         function close() {
 244                 $this->mOpened = false;
 245                 if ( $this->mConn ) {
 246                         return pg_close( $this->mConn );
 247                 } else {
 248                         return true;
 249                 }
 250         }
 251
 252         protected function doQuery( $sql ) {
 253                 if ( function_exists( 'mb_convert_encoding' ) ) {
 254                         $sql = mb_convert_encoding( $sql, 'UTF-8' );
 255                 }
 256                 $this->mLastResult = pg_query( $this->mConn, $sql );
 257                 $this->mAffectedRows = null; // use pg_affected_rows(mLastResult)
 258                 return $this->mLastResult;
 259         }
 260
 261         function queryIgnore( $sql, $fname = 'DatabasePostgres::queryIgnore' ) {
 262                 return $this->query( $sql, $fname, true );
 263         }
 264
 265         function freeResult( $res ) {
 266                 if ( $res instanceof ResultWrapper ) {
 267                         $res = $res->result;
 268                 }
 269                 wfSuppressWarnings();
 270                 $ok = pg_free_result( $res );
 271                 wfRestoreWarnings();
 272                 if ( !$ok ) {
 273                         throw new DBUnexpectedError( $this, "Unable to free Postgres result\n" );
 274                 }
 275         }
 276
 277         function fetchObject( $res ) {
 278                 if ( $res instanceof ResultWrapper ) {
 279                         $res = $res->result;
 280                 }
 281                 wfSuppressWarnings();
 282                 $row = pg_fetch_object( $res );
 283                 wfRestoreWarnings();
 284                 # @todo FIXME: HACK HACK HACK HACK debug
 285
 286                 # @todo hashar: not sure if the following test really trigger if the object
 287                 #          fetching failed.
 288                 if( pg_last_error( $this->mConn ) ) {
 289                         throw new DBUnexpectedError( $this, 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) ) );
 290                 }
 291                 return $row;
 292         }
 293
 294         function fetchRow( $res ) {
 295                 if ( $res instanceof ResultWrapper ) {
 296                         $res = $res->result;
 297                 }
 298                 wfSuppressWarnings();
 299                 $row = pg_fetch_array( $res );
 300                 wfRestoreWarnings();
 301                 if( pg_last_error( $this->mConn ) ) {
 302                         throw new DBUnexpectedError( $this, 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) ) );
 303                 }
 304                 return $row;
 305         }
 306
 307         function numRows( $res ) {
 308                 if ( $res instanceof ResultWrapper ) {
 309                         $res = $res->result;
 310                 }
 311                 wfSuppressWarnings();
 312                 $n = pg_num_rows( $res );
 313                 wfRestoreWarnings();
 314                 if( pg_last_error( $this->mConn ) ) {
 315                         throw new DBUnexpectedError( $this, 'SQL error: ' . htmlspecialchars( pg_last_error( $this->mConn ) ) );
 316                 }
 317                 return $n;
 318         }
 319
 320         function numFields( $res ) {
 321                 if ( $res instanceof ResultWrapper ) {
 322                         $res = $res->result;
 323                 }
 324                 return pg_num_fields( $res );
 325         }
 326
 327         function fieldName( $res, $n ) {
 328                 if ( $res instanceof ResultWrapper ) {
 329                         $res = $res->result;
 330                 }
 331                 return pg_field_name( $res, $n );
 332         }
 333
 334         /**
 335          * This must be called after nextSequenceVal
 336          * @return null
 337          */
 338         function insertId() {
 339                 return $this->mInsertId;
 340         }
 341
 342         function dataSeek( $res, $row ) {
 343                 if ( $res instanceof ResultWrapper ) {
 344                         $res = $res->result;
 345                 }
 346                 return pg_result_seek( $res, $row );
 347         }
 348
 349         function lastError() {
 350                 if ( $this->mConn ) {
 351                         return pg_last_error();
 352                 } else {
 353                         return 'No database connection';
 354                 }
 355         }
 356         function lastErrno() {
 357                 return pg_last_error() ? 1 : 0;
 358         }
 359
 360         function affectedRows() {
 361                 if ( !is_null( $this->mAffectedRows ) ) {
 362                         // Forced result for simulated queries
 363                         return $this->mAffectedRows;
 364                 }
 365                 if( empty( $this->mLastResult ) ) {
 366                         return 0;
 367                 }
 368                 return pg_affected_rows( $this->mLastResult );
 369         }
 370
 371         /**
 372          * Estimate rows in dataset
 373          * Returns estimated count, based on EXPLAIN output
 374          * This is not necessarily an accurate estimate, so use sparingly
 375          * Returns -1 if count cannot be found
 376          * Takes same arguments as Database::select()
 377          * @return int
 378          */
 379         function estimateRowCount( $table, $vars = '*', $conds='', $fname = 'DatabasePostgres::estimateRowCount', $options = array() ) {
 380                 $options['EXPLAIN'] = true;
 381                 $res = $this->select( $table, $vars, $conds, $fname, $options );
 382                 $rows = -1;
 383                 if ( $res ) {
 384                         $row = $this->fetchRow( $res );
 385                         $count = array();
 386                         if( preg_match( '/rows=(\d+)/', $row[0], $count ) ) {
 387                                 $rows = $count[1];
 388                         }
 389                 }
 390                 return $rows;
 391         }
 392
 393         /**
 394          * Returns information about an index
 395          * If errors are explicitly ignored, returns NULL on failure
 396          * @return bool|null
 397          */
 398         function indexInfo( $table, $index, $fname = 'DatabasePostgres::indexInfo' ) {
 399                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='$table'";
 400                 $res = $this->query( $sql, $fname );
 401                 if ( !$res ) {
 402                         return null;
 403                 }
 404                 foreach ( $res as $row ) {
 405                         if ( $row->indexname == $this->indexName( $index ) ) {
 406                                 return $row;
 407                         }
 408                 }
 409                 return false;
 410         }
 411
 412         function indexUnique( $table, $index, $fname = 'DatabasePostgres::indexUnique' ) {
 413                 $sql = "SELECT indexname FROM pg_indexes WHERE tablename='{$table}'".
 414                         " AND indexdef LIKE 'CREATE UNIQUE%(" .
 415                         $this->strencode( $this->indexName( $index ) ) .
 416                         ")'";
 417                 $res = $this->query( $sql, $fname );
 418                 if ( !$res ) {
 419                         return null;
 420                 }
 421                 foreach ( $res as $row ) {
 422                         return true;
 423                 }
 424                 return false;
 425         }
 426
 427         /**
 428          * INSERT wrapper, inserts an array into a table
 429          *
 430          * $args may be a single associative array, or an array of these with numeric keys,
 431          * for multi-row insert (Postgres version 8.2 and above only).
 432          *
 433          * @param $table   String: Name of the table to insert to.
 434          * @param $args    Array: Items to insert into the table.
 435          * @param $fname   String: Name of the function, for profiling
 436          * @param $options String or Array. Valid options: IGNORE
 437          *
 438          * @return bool Success of insert operation. IGNORE always returns true.
 439          */
 440         function insert( $table, $args, $fname = 'DatabasePostgres::insert', $options = array() ) {
 441                 if ( !count( $args ) ) {
 442                         return true;
 443                 }
 444
 445                 $table = $this->tableName( $table );
 446                 if (! isset( $this->numeric_version ) ) {
 447                         $this->getServerVersion();
 448                 }
 449
 450                 if ( !is_array( $options ) ) {
 451                         $options = array( $options );
 452                 }
 453
 454                 if ( isset( $args[0] ) && is_array( $args[0] ) ) {
 455                         $multi = true;
 456                         $keys = array_keys( $args[0] );
 457                 } else {
 458                         $multi = false;
 459                         $keys = array_keys( $args );
 460                 }
 461
 462                 // If IGNORE is set, we use savepoints to emulate mysql's behavior
 463                 $ignore = in_array( 'IGNORE', $options ) ? 'mw' : '';
 464
 465                 // If we are not in a transaction, we need to be for savepoint trickery
 466                 $didbegin = 0;
 467                 if ( $ignore ) {
 468                         if ( !$this->mTrxLevel ) {
 469                                 $this->begin( __METHOD__ );
 470                                 $didbegin = 1;
 471                         }
 472                         $olde = error_reporting( 0 );
 473                         // For future use, we may want to track the number of actual inserts
 474                         // Right now, insert (all writes) simply return true/false
 475                         $numrowsinserted = 0;
 476                 }
 477
 478                 $sql = "INSERT INTO $table (" . implode( ',', $keys ) . ') VALUES ';
 479
 480                 if ( $multi ) {
 481                         if ( $this->numeric_version >= 8.2 && !$ignore ) {
 482                                 $first = true;
 483                                 foreach ( $args as $row ) {
 484                                         if ( $first ) {
 485                                                 $first = false;
 486                                         } else {
 487                                                 $sql .= ',';
 488                                         }
 489                                         $sql .= '(' . $this->makeList( $row ) . ')';
 490                                 }
 491                                 $res = (bool)$this->query( $sql, $fname, $ignore );
 492                         } else {
 493                                 $res = true;
 494                                 $origsql = $sql;
 495                                 foreach ( $args as $row ) {
 496                                         $tempsql = $origsql;
 497                                         $tempsql .= '(' . $this->makeList( $row ) . ')';
 498
 499                                         if ( $ignore ) {
 500                                                 pg_query( $this->mConn, "SAVEPOINT $ignore" );
 501                                         }
 502
 503                                         $tempres = (bool)$this->query( $tempsql, $fname, $ignore );
 504
 505                                         if ( $ignore ) {
 506                                                 $bar = pg_last_error();
 507                                                 if ( $bar != false ) {
 508                                                         pg_query( $this->mConn, "ROLLBACK TO $ignore" );
 509                                                 } else {
 510                                                         pg_query( $this->mConn, "RELEASE $ignore" );
 511                                                         $numrowsinserted++;
 512                                                 }
 513                                         }
 514
 515                                         // If any of them fail, we fail overall for this function call
 516                                         // Note that this will be ignored if IGNORE is set
 517                                         if ( !$tempres ) {
 518                                                 $res = false;
 519                                         }
 520                                 }
 521                         }
 522                 } else {
 523                         // Not multi, just a lone insert
 524                         if ( $ignore ) {
 525                                 pg_query($this->mConn, "SAVEPOINT $ignore");
 526                         }
 527
 528                         $sql .= '(' . $this->makeList( $args ) . ')';
 529                         $res = (bool)$this->query( $sql, $fname, $ignore );
 530                         if ( $ignore ) {
 531                                 $bar = pg_last_error();
 532                                 if ( $bar != false ) {
 533                                         pg_query( $this->mConn, "ROLLBACK TO $ignore" );
 534                                 } else {
 535                                         pg_query( $this->mConn, "RELEASE $ignore" );
 536                                         $numrowsinserted++;
 537                                 }
 538                         }
 539                 }
 540                 if ( $ignore ) {
 541                         $olde = error_reporting( $olde );
 542                         if ( $didbegin ) {
 543                                 $this->commit( __METHOD__ );
 544                         }
 545
 546                         // Set the affected row count for the whole operation
 547                         $this->mAffectedRows = $numrowsinserted;
 548
 549                         // IGNORE always returns true
 550                         return true;
 551                 }
 552
 553                 return $res;
 554         }
 555
 556         /**
 557          * INSERT SELECT wrapper
 558          * $varMap must be an associative array of the form array( 'dest1' => 'source1', ...)
 559          * Source items may be literals rather then field names, but strings should be quoted with Database::addQuotes()
 560          * $conds may be "*" to copy the whole table
 561          * srcTable may be an array of tables.
 562          * @todo FIXME: Implement this a little better (seperate select/insert)?
 563          * @return bool
 564          */
 565         function insertSelect( $destTable, $srcTable, $varMap, $conds, $fname = 'DatabasePostgres::insertSelect',
 566                 $insertOptions = array(), $selectOptions = array() )
 567         {
 568                 $destTable = $this->tableName( $destTable );
 569
 570                 // If IGNORE is set, we use savepoints to emulate mysql's behavior
 571                 $ignore = in_array( 'IGNORE', $insertOptions ) ? 'mw' : '';
 572
 573                 if( is_array( $insertOptions ) ) {
 574                         $insertOptions = implode( ' ', $insertOptions ); // FIXME: This is unused
 575                 }
 576                 if( !is_array( $selectOptions ) ) {
 577                         $selectOptions = array( $selectOptions );
 578                 }
 579                 list( $startOpts, $useIndex, $tailOpts ) = $this->makeSelectOptions( $selectOptions );
 580                 if( is_array( $srcTable ) ) {
 581                         $srcTable = implode( ',', array_map( array( &$this, 'tableName' ), $srcTable ) );
 582                 } else {
 583                         $srcTable = $this->tableName( $srcTable );
 584                 }
 585
 586                 // If we are not in a transaction, we need to be for savepoint trickery
 587                 $didbegin = 0;
 588                 if ( $ignore ) {
 589                         if( !$this->mTrxLevel ) {
 590                                 $this->begin( __METHOD__ );
 591                                 $didbegin = 1;
 592                         }
 593                         $olde = error_reporting( 0 );
 594                         $numrowsinserted = 0;
 595                         pg_query( $this->mConn, "SAVEPOINT $ignore");
 596                 }
 597
 598                 $sql = "INSERT INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
 599                                 " SELECT $startOpts " . implode( ',', $varMap ) .
 600                                 " FROM $srcTable $useIndex";
 601
 602                 if ( $conds != '*' ) {
 603                         $sql .= ' WHERE ' . $this->makeList( $conds, LIST_AND );
 604                 }
 605
 606                 $sql .= " $tailOpts";
 607
 608                 $res = (bool)$this->query( $sql, $fname, $ignore );
 609                 if( $ignore ) {
 610                         $bar = pg_last_error();
 611                         if( $bar != false ) {
 612                                 pg_query( $this->mConn, "ROLLBACK TO $ignore" );
 613                         } else {
 614                                 pg_query( $this->mConn, "RELEASE $ignore" );
 615                                 $numrowsinserted++;
 616                         }
 617                         $olde = error_reporting( $olde );
 618                         if( $didbegin ) {
 619                                 $this->commit( __METHOD__ );
 620                         }
 621
 622                         // Set the affected row count for the whole operation
 623                         $this->mAffectedRows = $numrowsinserted;
 624
 625                         // IGNORE always returns true
 626                         return true;
 627                 }
 628
 629                 return $res;
 630         }
 631
 632         function tableName( $name, $format = 'quoted' ) {
 633                 # Replace reserved words with better ones
 634                 switch( $name ) {
 635                         case 'user':
 636                                 return 'mwuser';
 637                         case 'text':
 638                                 return 'pagecontent';
 639                         default:
 640                                 return parent::tableName( $name, $format );
 641                 }
 642         }
 643
 644         /**
 645          * Return the next in a sequence, save the value for retrieval via insertId()
 646          * @return null
 647          */
 648         function nextSequenceValue( $seqName ) {
 649                 $safeseq = str_replace( "'", "''", $seqName );
 650                 $res = $this->query( "SELECT nextval('$safeseq')" );
 651                 $row = $this->fetchRow( $res );
 652                 $this->mInsertId = $row[0];
 653                 return $this->mInsertId;
 654         }
 655
 656         /**
 657          * Return the current value of a sequence. Assumes it has been nextval'ed in this session.
 658          * @return
 659          */
 660         function currentSequenceValue( $seqName ) {
 661                 $safeseq = str_replace( "'", "''", $seqName );
 662                 $res = $this->query( "SELECT currval('$safeseq')" );
 663                 $row = $this->fetchRow( $res );
 664                 $currval = $row[0];
 665                 return $currval;
 666         }
 667
 668         # Returns the size of a text field, or -1 for "unlimited"
 669         function textFieldSize( $table, $field ) {
 670                 $table = $this->tableName( $table );
 671                 $sql = "SELECT t.typname as ftype,a.atttypmod as size
 672                         FROM pg_class c, pg_attribute a, pg_type t
 673                         WHERE relname='$table' AND a.attrelid=c.oid AND
 674                                 a.atttypid=t.oid and a.attname='$field'";
 675                 $res =$this->query( $sql );
 676                 $row = $this->fetchObject( $res );
 677                 if ( $row->ftype == 'varchar' ) {
 678                         $size = $row->size - 4;
 679                 } else {
 680                         $size = $row->size;
 681                 }
 682                 return $size;
 683         }
 684
 685         function limitResult( $sql, $limit, $offset = false ) {
 686                 return "$sql LIMIT $limit " . ( is_numeric( $offset ) ? " OFFSET {$offset} " : '' );
 687         }
 688
 689         function wasDeadlock() {
 690                 return $this->lastErrno() == '40P01';
 691         }
 692
 693         function duplicateTableStructure( $oldName, $newName, $temporary = false, $fname = 'DatabasePostgres::duplicateTableStructure' ) {
 694                 $newName = $this->addIdentifierQuotes( $newName );
 695                 $oldName = $this->addIdentifierQuotes( $oldName );
 696                 return $this->query( 'CREATE ' . ( $temporary ? 'TEMPORARY ' : '' ) . " TABLE $newName (LIKE $oldName INCLUDING DEFAULTS)", $fname );
 697         }
 698
 699         function listTables( $prefix = null, $fname = 'DatabasePostgres::listTables' ) {
 700                 global $wgDBmwschema;
 701                 $eschema = $this->addQuotes( $wgDBmwschema );
 702                 $result = $this->query( "SELECT tablename FROM pg_tables WHERE schemaname = $eschema", $fname );
 703
 704                 $endArray = array();
 705
 706                 foreach( $result as $table ) {
 707                         $vars = get_object_vars($table);
 708                         $table = array_pop( $vars );
 709                         if( !$prefix || strpos( $table, $prefix ) === 0 ) {
 710                                 $endArray[] = $table;
 711                         }
 712                 }
 713
 714                 return $endArray;
 715         }
 716
 717         function timestamp( $ts = 0 ) {
 718                 return wfTimestamp( TS_POSTGRES, $ts );
 719         }
 720
 721         /**
 722          * Return aggregated value function call
 723          */
 724         function aggregateValue( $valuedata, $valuename = 'value' ) {
 725                 return $valuedata;
 726         }
 727
 728         /**
 729          * @return string wikitext of a link to the server software's web site
 730          */
 731         public static function getSoftwareLink() {
 732                 return '[http://www.postgresql.org/ PostgreSQL]';
 733         }
 734
 735         /**
 736          * @return string Version information from the database
 737          */
 738         function getServerVersion() {
 739                 if ( !isset( $this->numeric_version ) ) {
 740                         $versionInfo = pg_version( $this->mConn );
 741                         if ( version_compare( $versionInfo['client'], '7.4.0', 'lt' ) ) {
 742                                 // Old client, abort install
 743                                 $this->numeric_version = '7.3 or earlier';
 744                         } elseif ( isset( $versionInfo['server'] ) ) {
 745                                 // Normal client
 746                                 $this->numeric_version = $versionInfo['server'];
 747                         } else {
 748                                 // Bug 16937: broken pgsql extension from PHP<5.3
 749                                 $this->numeric_version = pg_parameter_status( $this->mConn, 'server_version' );
 750                         }
 751                 }
 752                 return $this->numeric_version;
 753         }
 754
 755         /**
 756          * Query whether a given relation exists (in the given schema, or the
 757          * default mw one if not given)
 758          * @return bool
 759          */
 760         function relationExists( $table, $types, $schema = false ) {
 761                 global $wgDBmwschema;
 762                 if ( !is_array( $types ) ) {
 763                         $types = array( $types );
 764                 }
 765                 if ( !$schema ) {
 766                         $schema = $wgDBmwschema;
 767                 }
 768                 $table = $this->tableName( $table, 'raw' );
 769                 $etable = $this->addQuotes( $table );
 770                 $eschema = $this->addQuotes( $schema );
 771                 $SQL = "SELECT 1 FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n "
 772                         . "WHERE c.relnamespace = n.oid AND c.relname = $etable AND n.nspname = $eschema "
 773                         . "AND c.relkind IN ('" . implode( "','", $types ) . "')";
 774                 $res = $this->query( $SQL );
 775                 $count = $res ? $res->numRows() : 0;
 776                 return (bool)$count;
 777         }
 778
 779         /**
 780          * For backward compatibility, this function checks both tables and
 781          * views.
 782          * @return bool
 783          */
 784         function tableExists( $table, $fname = __METHOD__, $schema = false ) {
 785                 return $this->relationExists( $table, array( 'r', 'v' ), $schema );
 786         }
 787
 788         function sequenceExists( $sequence, $schema = false ) {
 789                 return $this->relationExists( $sequence, 'S', $schema );
 790         }
 791
 792         function triggerExists( $table, $trigger ) {
 793                 global $wgDBmwschema;
 794
 795                 $q = <<<SQL
 796         SELECT 1 FROM pg_class, pg_namespace, pg_trigger
 797                 WHERE relnamespace=pg_namespace.oid AND relkind='r'
 798                           AND tgrelid=pg_class.oid
 799                           AND nspname=%s AND relname=%s AND tgname=%s
 800 SQL;
 801                 $res = $this->query(
 802                         sprintf(
 803                                 $q,
 804                                 $this->addQuotes( $wgDBmwschema ),
 805                                 $this->addQuotes( $table ),
 806                                 $this->addQuotes( $trigger )
 807                         )
 808                 );
 809                 if ( !$res ) {
 810                         return null;
 811                 }
 812                 $rows = $res->numRows();
 813                 return $rows;
 814         }
 815
 816         function ruleExists( $table, $rule ) {
 817                 global $wgDBmwschema;
 818                 $exists = $this->selectField( 'pg_rules', 'rulename',
 819                         array(
 820                                 'rulename' => $rule,
 821                                 'tablename' => $table,
 822                                 'schemaname' => $wgDBmwschema
 823                         )
 824                 );
 825                 return $exists === $rule;
 826         }
 827
 828         function constraintExists( $table, $constraint ) {
 829                 global $wgDBmwschema;
 830                 $SQL = sprintf( "SELECT 1 FROM information_schema.table_constraints ".
 831                            "WHERE constraint_schema = %s AND table_name = %s AND constraint_name = %s",
 832                         $this->addQuotes( $wgDBmwschema ),
 833                         $this->addQuotes( $table ),
 834                         $this->addQuotes( $constraint )
 835                 );
 836                 $res = $this->query( $SQL );
 837                 if ( !$res ) {
 838                         return null;
 839                 }
 840                 $rows = $res->numRows();
 841                 return $rows;
 842         }
 843
 844         /**
 845          * Query whether a given schema exists. Returns true if it does, false if it doesn't.
 846          * @return bool
 847          */
 848         function schemaExists( $schema ) {
 849                 $exists = $this->selectField( '"pg_catalog"."pg_namespace"', 1,
 850                         array( 'nspname' => $schema ), __METHOD__ );
 851                 return (bool)$exists;
 852         }
 853
 854         /**
 855          * Returns true if a given role (i.e. user) exists, false otherwise.
 856          * @return bool
 857          */
 858         function roleExists( $roleName ) {
 859                 $exists = $this->selectField( '"pg_catalog"."pg_roles"', 1,
 860                         array( 'rolname' => $roleName ), __METHOD__ );
 861                 return (bool)$exists;
 862         }
 863
 864         function fieldInfo( $table, $field ) {
 865                 return PostgresField::fromText( $this, $table, $field );
 866         }
 867
 868         /**
 869          * pg_field_type() wrapper
 870          * @return string
 871          */
 872         function fieldType( $res, $index ) {
 873                 if ( $res instanceof ResultWrapper ) {
 874                         $res = $res->result;
 875                 }
 876                 return pg_field_type( $res, $index );
 877         }
 878
 879         /* Not even sure why this is used in the main codebase... */
 880         function limitResultForUpdate( $sql, $num ) {
 881                 return $sql;
 882         }
 883
 884         /**
 885          * @param $b
 886          * @return Blob
 887          */
 888         function encodeBlob( $b ) {
 889                 return new Blob( pg_escape_bytea( $this->mConn, $b ) );
 890         }
 891
 892         function decodeBlob( $b ) {
 893                 if ( $b instanceof Blob ) {
 894                         $b = $b->fetch();
 895                 }
 896                 return pg_unescape_bytea( $b );
 897         }
 898
 899         function strencode( $s ) { # Should not be called by us
 900                 return pg_escape_string( $this->mConn, $s );
 901         }
 902
 903         /**
 904          * @param $s null|bool|Blob
 905          * @return int|string
 906          */
 907         function addQuotes( $s ) {
 908                 if ( is_null( $s ) ) {
 909                         return 'NULL';
 910                 } elseif ( is_bool( $s ) ) {
 911                         return intval( $s );
 912                 } elseif ( $s instanceof Blob ) {
 913                         return "'" . $s->fetch( $s ) . "'";
 914                 }
 915                 return "'" . pg_escape_string( $this->mConn, $s ) . "'";
 916         }
 917
 918         /**
 919          * Postgres specific version of replaceVars.
 920          * Calls the parent version in Database.php
 921          *
 922          * @private
 923          *
 924          * @param $ins String: SQL string, read from a stream (usually tables.sql)
 925          *
 926          * @return string SQL string
 927          */
 928         protected function replaceVars( $ins ) {
 929                 $ins = parent::replaceVars( $ins );
 930
 931                 if ( $this->numeric_version >= 8.3 ) {
 932                         // Thanks for not providing backwards-compatibility, 8.3
 933                         $ins = preg_replace( "/to_tsvector\s*\(\s*'default'\s*,/", 'to_tsvector(', $ins );
 934                 }
 935
 936                 if ( $this->numeric_version <= 8.1 ) { // Our minimum version
 937                         $ins = str_replace( 'USING gin', 'USING gist', $ins );
 938                 }
 939
 940                 return $ins;
 941         }
 942
 943         /**
 944          * Various select options
 945          *
 946          * @private
 947          *
 948          * @param $options Array: an associative array of options to be turned into
 949          *              an SQL query, valid keys are listed in the function.
 950          * @return array
 951          */
 952         function makeSelectOptions( $options ) {
 953                 $preLimitTail = $postLimitTail = '';
 954                 $startOpts = $useIndex = '';
 955
 956                 $noKeyOptions = array();
 957                 foreach ( $options as $key => $option ) {
 958                         if ( is_numeric( $key ) ) {
 959                                 $noKeyOptions[$option] = true;
 960                         }
 961                 }
 962
 963                 if ( isset( $options['GROUP BY'] ) ) {
 964                         $gb = is_array( $options['GROUP BY'] )
 965                                 ? implode( ',', $options['GROUP BY'] )
 966                                 : $options['GROUP BY'];
 967                         $preLimitTail .= " GROUP BY {$gb}";
 968                 }
 969
 970                 if ( isset( $options['HAVING'] ) ) {
 971                         $preLimitTail .= " HAVING {$options['HAVING']}";
 972                 }
 973
 974                 if ( isset( $options['ORDER BY'] ) ) {
 975                         $ob = is_array( $options['ORDER BY'] )
 976                                 ? implode( ',', $options['ORDER BY'] )
 977                                 : $options['ORDER BY'];
 978                         $preLimitTail .= " ORDER BY {$ob}";
 979                 }
 980
 981                 //if ( isset( $options['LIMIT'] ) ) {
 982                 //      $tailOpts .= $this->limitResult( '', $options['LIMIT'],
 983                 //              isset( $options['OFFSET'] ) ? $options['OFFSET']
 984                 //              : false );
 985                 //}
 986
 987                 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
 988                         $postLimitTail .= ' FOR UPDATE';
 989                 }
 990                 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
 991                         $postLimitTail .= ' LOCK IN SHARE MODE';
 992                 }
 993                 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
 994                         $startOpts .= 'DISTINCT';
 995                 }
 996
 997                 return array( $startOpts, $useIndex, $preLimitTail, $postLimitTail );
 998         }
 999
1000         function setFakeMaster( $enabled = true ) {}
1001
1002         function getDBname() {
1003                 return $this->mDBname;
1004         }
1005
1006         function getServer() {
1007                 return $this->mServer;
1008         }
1009
1010         function buildConcat( $stringList ) {
1011                 return implode( ' || ', $stringList );
1012         }
1013
1014         public function getSearchEngine() {
1015                 return 'SearchPostgres';
1016         }
1017
1018         public function streamStatementEnd( &$sql, &$newLine ) {
1019                 # Allow dollar quoting for function declarations
1020                 if ( substr( $newLine, 0, 4 ) == '$mw$' ) {
1021                         if ( $this->delimiter ) {
1022                                 $this->delimiter = false;
1023                         }
1024                         else {
1025                                 $this->delimiter = ';';
1026                         }
1027                 }
1028                 return parent::streamStatementEnd( $sql, $newLine );
1029         }
1030 } // end DatabasePostgres class