includes/api/ApiQueryBase.php

   1 <?php
   2 /**
   3  *
   4  *
   5  * Created on Sep 7, 2006
   6  *
   7  * Copyright © 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22  * http://www.gnu.org/copyleft/gpl.html
  23  *
  24  * @file
  25  */
  26
  27 if ( !defined( 'MEDIAWIKI' ) ) {
  28         // Eclipse helper - will be ignored in production
  29         require_once( 'ApiBase.php' );
  30 }
  31
  32 /**
  33  * This is a base class for all Query modules.
  34  * It provides some common functionality such as constructing various SQL
  35  * queries.
  36  *
  37  * @ingroup API
  38  */
  39 abstract class ApiQueryBase extends ApiBase {
  40
  41         private $mQueryModule, $mDb, $tables, $where, $fields, $options, $join_conds;
  42
  43         public function __construct( ApiBase $query, $moduleName, $paramPrefix = '' ) {
  44                 parent::__construct( $query->getMain(), $moduleName, $paramPrefix );
  45                 $this->mQueryModule = $query;
  46                 $this->mDb = null;
  47                 $this->resetQueryParams();
  48         }
  49
  50         /**
  51          * Get the cache mode for the data generated by this module. Override
  52          * this in the module subclass. For possible return values and other
  53          * details about cache modes, see ApiMain::setCacheMode()
  54          *
  55          * Public caching will only be allowed if *all* the modules that supply
  56          * data for a given request return a cache mode of public.
  57          *
  58          * @return string
  59          */
  60         public function getCacheMode( $params ) {
  61                 return 'private';
  62         }
  63
  64         /**
  65          * Blank the internal arrays with query parameters
  66          */
  67         protected function resetQueryParams() {
  68                 $this->tables = array();
  69                 $this->where = array();
  70                 $this->fields = array();
  71                 $this->options = array();
  72                 $this->join_conds = array();
  73         }
  74
  75         /**
  76          * Add a set of tables to the internal array
  77          * @param $tables mixed Table name or array of table names
  78          * @param $alias mixed Table alias, or null for no alias. Cannot be
  79          *  used with multiple tables
  80          */
  81         protected function addTables( $tables, $alias = null ) {
  82                 if ( is_array( $tables ) ) {
  83                         if ( !is_null( $alias ) ) {
  84                                 ApiBase::dieDebug( __METHOD__, 'Multiple table aliases not supported' );
  85                         }
  86                         $this->tables = array_merge( $this->tables, $tables );
  87                 } else {
  88                         if ( !is_null( $alias ) ) {
  89                                 $this->tables[$alias] = $tables;
  90                         } else {
  91                                 $this->tables[] = $tables;
  92                         }
  93                 }
  94         }
  95
  96         /**
  97          * Add a set of JOIN conditions to the internal array
  98          *
  99          * JOIN conditions are formatted as array( tablename => array(jointype,
 100          * conditions) e.g. array('page' => array('LEFT JOIN',
 101          * 'page_id=rev_page')) . conditions may be a string or an
 102          * addWhere()-style array
 103          * @param $join_conds array JOIN conditions
 104          */
 105         protected function addJoinConds( $join_conds ) {
 106                 if ( !is_array( $join_conds ) ) {
 107                         ApiBase::dieDebug( __METHOD__, 'Join conditions have to be arrays' );
 108                 }
 109                 $this->join_conds = array_merge( $this->join_conds, $join_conds );
 110         }
 111
 112         /**
 113          * Add a set of fields to select to the internal array
 114          * @param $value array|string Field name or array of field names
 115          */
 116         protected function addFields( $value ) {
 117                 if ( is_array( $value ) ) {
 118                         $this->fields = array_merge( $this->fields, $value );
 119                 } else {
 120                         $this->fields[] = $value;
 121                 }
 122         }
 123
 124         /**
 125          * Same as addFields(), but add the fields only if a condition is met
 126          * @param $value array|string See addFields()
 127          * @param $condition bool If false, do nothing
 128          * @return bool $condition
 129          */
 130         protected function addFieldsIf( $value, $condition ) {
 131                 if ( $condition ) {
 132                         $this->addFields( $value );
 133                         return true;
 134                 }
 135                 return false;
 136         }
 137
 138         /**
 139          * Add a set of WHERE clauses to the internal array.
 140          * Clauses can be formatted as 'foo=bar' or array('foo' => 'bar'),
 141          * the latter only works if the value is a constant (i.e. not another field)
 142          *
 143          * If $value is an empty array, this function does nothing.
 144          *
 145          * For example, array('foo=bar', 'baz' => 3, 'bla' => 'foo') translates
 146          * to "foo=bar AND baz='3' AND bla='foo'"
 147          * @param $value mixed String or array
 148          */
 149         protected function addWhere( $value ) {
 150                 if ( is_array( $value ) ) {
 151                         // Sanity check: don't insert empty arrays,
 152                         // Database::makeList() chokes on them
 153                         if ( count( $value ) ) {
 154                                 $this->where = array_merge( $this->where, $value );
 155                         }
 156                 } else {
 157                         $this->where[] = $value;
 158                 }
 159         }
 160
 161         /**
 162          * Same as addWhere(), but add the WHERE clauses only if a condition is met
 163          * @param $value mixed See addWhere()
 164          * @param $condition bool If false, do nothing
 165          * @return bool $condition
 166          */
 167         protected function addWhereIf( $value, $condition ) {
 168                 if ( $condition ) {
 169                         $this->addWhere( $value );
 170                         return true;
 171                 }
 172                 return false;
 173         }
 174
 175         /**
 176          * Equivalent to addWhere(array($field => $value))
 177          * @param $field string Field name
 178          * @param $value string Value; ignored if null or empty array;
 179          */
 180         protected function addWhereFld( $field, $value ) {
 181                 // Use count() to its full documented capabilities to simultaneously
 182                 // test for null, empty array or empty countable object
 183                 if ( count( $value ) ) {
 184                         $this->where[$field] = $value;
 185                 }
 186         }
 187
 188         /**
 189          * Add a WHERE clause corresponding to a range, and an ORDER BY
 190          * clause to sort in the right direction
 191          * @param $field string Field name
 192          * @param $dir string If 'newer', sort in ascending order, otherwise
 193          *  sort in descending order
 194          * @param $start string Value to start the list at. If $dir == 'newer'
 195          *  this is the lower boundary, otherwise it's the upper boundary
 196          * @param $end string Value to end the list at. If $dir == 'newer' this
 197          *  is the upper boundary, otherwise it's the lower boundary
 198          * @param $sort bool If false, don't add an ORDER BY clause
 199          */
 200         protected function addWhereRange( $field, $dir, $start, $end, $sort = true ) {
 201                 $isDirNewer = ( $dir === 'newer' );
 202                 $after = ( $isDirNewer ? '>=' : '<=' );
 203                 $before = ( $isDirNewer ? '<=' : '>=' );
 204                 $db = $this->getDB();
 205
 206                 if ( !is_null( $start ) ) {
 207                         $this->addWhere( $field . $after . $db->addQuotes( $start ) );
 208                 }
 209
 210                 if ( !is_null( $end ) ) {
 211                         $this->addWhere( $field . $before . $db->addQuotes( $end ) );
 212                 }
 213
 214                 if ( $sort ) {
 215                         $order = $field . ( $isDirNewer ? '' : ' DESC' );
 216                         if ( !isset( $this->options['ORDER BY'] ) ) {
 217                                 $this->addOption( 'ORDER BY', $order );
 218                         } else {
 219                                 $this->addOption( 'ORDER BY', $this->options['ORDER BY'] . ', ' . $order );
 220                         }
 221                 }
 222         }
 223
 224         /**
 225          * Add an option such as LIMIT or USE INDEX. If an option was set
 226          * before, the old value will be overwritten
 227          * @param $name string Option name
 228          * @param $value string Option value
 229          */
 230         protected function addOption( $name, $value = null ) {
 231                 if ( is_null( $value ) ) {
 232                         $this->options[] = $name;
 233                 } else {
 234                         $this->options[$name] = $value;
 235                 }
 236         }
 237
 238         /**
 239          * Execute a SELECT query based on the values in the internal arrays
 240          * @param $method string Function the query should be attributed to.
 241          *  You should usually use __METHOD__ here
 242          * @param $extraQuery array Query data to add but not store in the object
 243          *  Format is array( 'tables' => ..., 'fields' => ..., 'where' => ..., 'options' => ..., 'join_conds' => ... )
 244          * @return ResultWrapper
 245          */
 246         protected function select( $method, $extraQuery = array() ) {
 247
 248                 $tables = array_merge( $this->tables, isset( $extraQuery['tables'] ) ? (array)$extraQuery['tables'] : array() );
 249                 $fields = array_merge( $this->fields, isset( $extraQuery['fields'] ) ? (array)$extraQuery['fields'] : array() );
 250                 $where = array_merge( $this->where, isset( $extraQuery['where'] ) ? (array)$extraQuery['where'] : array() );
 251                 $options = array_merge( $this->options, isset( $extraQuery['options'] ) ? (array)$extraQuery['options'] : array() );
 252                 $join_conds = array_merge( $this->join_conds, isset( $extraQuery['join_conds'] ) ? (array)$extraQuery['join_conds'] : array() );
 253
 254                 // getDB has its own profileDBIn/Out calls
 255                 $db = $this->getDB();
 256
 257                 $this->profileDBIn();
 258                 $res = $db->select( $tables, $fields, $where, $method, $options, $join_conds );
 259                 $this->profileDBOut();
 260
 261                 return $res;
 262         }
 263
 264         /**
 265          * Estimate the row count for the SELECT query that would be run if we
 266          * called select() right now, and check if it's acceptable.
 267          * @return bool true if acceptable, false otherwise
 268          */
 269         protected function checkRowCount() {
 270                 $db = $this->getDB();
 271                 $this->profileDBIn();
 272                 $rowcount = $db->estimateRowCount( $this->tables, $this->fields, $this->where, __METHOD__, $this->options );
 273                 $this->profileDBOut();
 274
 275                 global $wgAPIMaxDBRows;
 276                 if ( $rowcount > $wgAPIMaxDBRows ) {
 277                         return false;
 278                 }
 279                 return true;
 280         }
 281
 282         /**
 283          * Add information (title and namespace) about a Title object to a
 284          * result array
 285          * @param $arr array Result array à la ApiResult
 286          * @param $title Title
 287          * @param $prefix string Module prefix
 288          */
 289         public static function addTitleInfo( &$arr, $title, $prefix = '' ) {
 290                 $arr[$prefix . 'ns'] = intval( $title->getNamespace() );
 291                 $arr[$prefix . 'title'] = $title->getPrefixedText();
 292         }
 293
 294         /**
 295          * Override this method to request extra fields from the pageSet
 296          * using $pageSet->requestField('fieldName')
 297          * @param $pageSet ApiPageSet
 298          */
 299         public function requestExtraData( $pageSet ) {
 300         }
 301
 302         /**
 303          * Get the main Query module
 304          * @return ApiQuery
 305          */
 306         public function getQuery() {
 307                 return $this->mQueryModule;
 308         }
 309
 310         /**
 311          * Add a sub-element under the page element with the given page ID
 312          * @param $pageId int Page ID
 313          * @param $data array Data array à la ApiResult
 314          * @return bool Whether the element fit in the result
 315          */
 316         protected function addPageSubItems( $pageId, $data ) {
 317                 $result = $this->getResult();
 318                 $result->setIndexedTagName( $data, $this->getModulePrefix() );
 319                 return $result->addValue( array( 'query', 'pages', intval( $pageId ) ),
 320                         $this->getModuleName(),
 321                         $data );
 322         }
 323
 324         /**
 325          * Same as addPageSubItems(), but one element of $data at a time
 326          * @param $pageId int Page ID
 327          * @param $item array Data array à la ApiResult
 328          * @param $elemname string XML element name. If null, getModuleName()
 329          *  is used
 330          * @return bool Whether the element fit in the result
 331          */
 332         protected function addPageSubItem( $pageId, $item, $elemname = null ) {
 333                 if ( is_null( $elemname ) ) {
 334                         $elemname = $this->getModulePrefix();
 335                 }
 336                 $result = $this->getResult();
 337                 $fit = $result->addValue( array( 'query', 'pages', $pageId,
 338                                          $this->getModuleName() ), null, $item );
 339                 if ( !$fit ) {
 340                         return false;
 341                 }
 342                 $result->setIndexedTagName_internal( array( 'query', 'pages', $pageId,
 343                                 $this->getModuleName() ), $elemname );
 344                 return true;
 345         }
 346
 347         /**
 348          * Set a query-continue value
 349          * @param $paramName string Parameter name
 350          * @param $paramValue string Parameter value
 351          */
 352         protected function setContinueEnumParameter( $paramName, $paramValue ) {
 353                 $paramName = $this->encodeParamName( $paramName );
 354                 $msg = array( $paramName => $paramValue );
 355                 $result = $this->getResult();
 356                 $result->disableSizeCheck();
 357                 $result->addValue( 'query-continue', $this->getModuleName(), $msg );
 358                 $result->enableSizeCheck();
 359         }
 360
 361         /**
 362          * Get the Query database connection (read-only)
 363          * @return DatabaseBase
 364          */
 365         protected function getDB() {
 366                 if ( is_null( $this->mDb ) ) {
 367                         $apiQuery = $this->getQuery();
 368                         $this->mDb = $apiQuery->getDB();
 369                 }
 370                 return $this->mDb;
 371         }
 372
 373         /**
 374          * Selects the query database connection with the given name.
 375          * See ApiQuery::getNamedDB() for more information
 376          * @param $name string Name to assign to the database connection
 377          * @param $db int One of the DB_* constants
 378          * @param $groups array Query groups
 379          * @return Database
 380          */
 381         public function selectNamedDB( $name, $db, $groups ) {
 382                 $this->mDb = $this->getQuery()->getNamedDB( $name, $db, $groups );
 383         }
 384
 385         /**
 386          * Get the PageSet object to work on
 387          * @return ApiPageSet
 388          */
 389         protected function getPageSet() {
 390                 return $this->getQuery()->getPageSet();
 391         }
 392
 393         /**
 394          * Convert a title to a DB key
 395          * @param $title string Page title with spaces
 396          * @return string Page title with underscores
 397          */
 398         public function titleToKey( $title ) {
 399                 // Don't throw an error if we got an empty string
 400                 if ( trim( $title ) == '' ) {
 401                         return '';
 402                 }
 403                 $t = Title::newFromText( $title );
 404                 if ( !$t ) {
 405                         $this->dieUsageMsg( array( 'invalidtitle', $title ) );
 406                 }
 407                 return $t->getPrefixedDbKey();
 408         }
 409
 410         /**
 411          * The inverse of titleToKey()
 412          * @param $key string Page title with underscores
 413          * @return string Page title with spaces
 414          */
 415         public function keyToTitle( $key ) {
 416                 // Don't throw an error if we got an empty string
 417                 if ( trim( $key ) == '' ) {
 418                         return '';
 419                 }
 420                 $t = Title::newFromDbKey( $key );
 421                 // This really shouldn't happen but we gotta check anyway
 422                 if ( !$t ) {
 423                         $this->dieUsageMsg( array( 'invalidtitle', $key ) );
 424                 }
 425                 return $t->getPrefixedText();
 426         }
 427
 428         /**
 429          * An alternative to titleToKey() that doesn't trim trailing spaces
 430          * @param $titlePart string Title part with spaces
 431          * @return string Title part with underscores
 432          */
 433         public function titlePartToKey( $titlePart ) {
 434                 return substr( $this->titleToKey( $titlePart . 'x' ), 0, - 1 );
 435         }
 436
 437         /**
 438          * An alternative to keyToTitle() that doesn't trim trailing spaces
 439          * @param $keyPart string Key part with spaces
 440          * @return string Key part with underscores
 441          */
 442         public function keyPartToTitle( $keyPart ) {
 443                 return substr( $this->keyToTitle( $keyPart . 'x' ), 0, - 1 );
 444         }
 445
 446         /**
 447          * Gets the personalised direction parameter description
 448          *
 449          * @param string $p ModulePrefix
 450          * @param string $extraDirText Any extra text to be appended on the description
 451          * @return array
 452          */
 453         public function getDirectionDescription( $p = '', $extraDirText = '' ) {
 454                 return array(
 455                                 "In which direction to enumerate{$extraDirText}",
 456                                 " newer          - List oldest first. Note: {$p}start has to be before {$p}end.",
 457                                 " older          - List newest first (default). Note: {$p}start has to be later than {$p}end.",
 458                         );
 459         }
 460
 461         /**
 462          * @param $query String
 463          * @param $protocol String
 464          * @return null|string
 465          */
 466         public function prepareUrlQuerySearchString( $query = null, $protocol = null) {
 467                 $db = $this->getDb();
 468                 if ( !is_null( $query ) || $query != '' ) {
 469                         if ( is_null( $protocol ) ) {
 470                                 $protocol = 'http://';
 471                         }
 472
 473                         $likeQuery = LinkFilter::makeLikeArray( $query, $protocol );
 474                         if ( !$likeQuery ) {
 475                                 $this->dieUsage( 'Invalid query', 'bad_query' );
 476                         }
 477
 478                         $likeQuery = LinkFilter::keepOneWildcard( $likeQuery );
 479                         return 'el_index ' . $db->buildLike( $likeQuery );
 480                 } elseif ( !is_null( $protocol ) ) {
 481                         return 'el_index ' . $db->buildLike( "$protocol", $db->anyString() );
 482                 }
 483
 484                 return null;
 485         }
 486
 487         /**
 488          * Filters hidden users (where the user doesn't have the right to view them)
 489          * Also adds relevant block information
 490          *
 491          * @param bool $showBlockInfo
 492          * @return void
 493          */
 494         public function showHiddenUsersAddBlockInfo( $showBlockInfo ) {
 495                 global $wgUser;
 496                 $userCanViewHiddenUsers = $wgUser->isAllowed( 'hideuser' );
 497
 498                 if ( $showBlockInfo || !$userCanViewHiddenUsers ) {
 499                         $this->addTables( 'ipblocks' );
 500                         $this->addJoinConds( array(
 501                                 'ipblocks' => array( 'LEFT JOIN', 'ipb_user=user_id' ),
 502                         ) );
 503
 504                         $this->addFields( 'ipb_deleted' );
 505
 506                         if ( $showBlockInfo ) {
 507                                 $this->addFields( array( 'ipb_reason', 'ipb_by_text', 'ipb_expiry' ) );
 508                         }
 509
 510                         // Don't show hidden names
 511                         if ( !$userCanViewHiddenUsers ) {
 512                                 $this->addWhere( 'ipb_deleted = 0 OR ipb_deleted IS NULL' );
 513                         }
 514                 }
 515         }
 516
 517         /**
 518          * @param $hash string
 519          * @return bool
 520          */
 521         public function validateSha1Hash( $hash ) {
 522                 return preg_match( '/[a-fA-F0-9]{40}/', $hash );
 523         }
 524
 525         /**
 526          * @param $hash string
 527          * @return bool
 528          */
 529         public function validateSha1Base36Hash( $hash ) {
 530                 return preg_match( '/[a-zA-Z0-9]{31}/', $hash );
 531         }
 532
 533         /**
 534          * @return array
 535          */
 536         public function getPossibleErrors() {
 537                 return array_merge( parent::getPossibleErrors(), array(
 538                         array( 'invalidtitle', 'title' ),
 539                         array( 'invalidtitle', 'key' ),
 540                 ) );
 541         }
 542
 543         /**
 544          * Get version string for use in the API help output
 545          * @return string
 546          */
 547         public static function getBaseVersion() {
 548                 return __CLASS__ . ': $Id$';
 549         }
 550 }
 551
 552 /**
 553  * @ingroup API
 554  */
 555 abstract class ApiQueryGeneratorBase extends ApiQueryBase {
 556
 557         private $mIsGenerator;
 558
 559         public function __construct( $query, $moduleName, $paramPrefix = '' ) {
 560                 parent::__construct( $query, $moduleName, $paramPrefix );
 561                 $this->mIsGenerator = false;
 562         }
 563
 564         /**
 565          * Switch this module to generator mode. By default, generator mode is
 566          * switched off and the module acts like a normal query module.
 567          */
 568         public function setGeneratorMode() {
 569                 $this->mIsGenerator = true;
 570         }
 571
 572         /**
 573          * Overrides base class to prepend 'g' to every generator parameter
 574          * @param $paramName string Parameter name
 575          * @return string Prefixed parameter name
 576          */
 577         public function encodeParamName( $paramName ) {
 578                 if ( $this->mIsGenerator ) {
 579                         return 'g' . parent::encodeParamName( $paramName );
 580                 } else {
 581                         return parent::encodeParamName( $paramName );
 582                 }
 583         }
 584
 585         /**
 586          * Execute this module as a generator
 587          * @param $resultPageSet ApiPageSet: All output should be appended to
 588          *  this object
 589          */
 590         public abstract function executeGenerator( $resultPageSet );
 591 }