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 /**
  28  * This is a base class for all Query modules.
  29  * It provides some common functionality such as constructing various SQL
  30  * queries.
  31  *
  32  * @ingroup API
  33  */
  34 abstract class ApiQueryBase extends ApiBase {
  35
  36         private $mQueryModule, $mDb, $tables, $where, $fields, $options, $join_conds;
  37
  38         public function __construct( ApiBase $query, $moduleName, $paramPrefix = '' ) {
  39                 parent::__construct( $query->getMain(), $moduleName, $paramPrefix );
  40                 $this->mQueryModule = $query;
  41                 $this->mDb = null;
  42                 $this->resetQueryParams();
  43         }
  44
  45         /**
  46          * Get the cache mode for the data generated by this module. Override
  47          * this in the module subclass. For possible return values and other
  48          * details about cache modes, see ApiMain::setCacheMode()
  49          *
  50          * Public caching will only be allowed if *all* the modules that supply
  51          * data for a given request return a cache mode of public.
  52          *
  53          * @param $params
  54          * @return string
  55          */
  56         public function getCacheMode( $params ) {
  57                 return 'private';
  58         }
  59
  60         /**
  61          * Blank the internal arrays with query parameters
  62          */
  63         protected function resetQueryParams() {
  64                 $this->tables = array();
  65                 $this->where = array();
  66                 $this->fields = array();
  67                 $this->options = array();
  68                 $this->join_conds = array();
  69         }
  70
  71         /**
  72          * Add a set of tables to the internal array
  73          * @param $tables mixed Table name or array of table names
  74          * @param $alias mixed Table alias, or null for no alias. Cannot be
  75          *  used with multiple tables
  76          */
  77         protected function addTables( $tables, $alias = null ) {
  78                 if ( is_array( $tables ) ) {
  79                         if ( !is_null( $alias ) ) {
  80                                 ApiBase::dieDebug( __METHOD__, 'Multiple table aliases not supported' );
  81                         }
  82                         $this->tables = array_merge( $this->tables, $tables );
  83                 } else {
  84                         if ( !is_null( $alias ) ) {
  85                                 $this->tables[$alias] = $tables;
  86                         } else {
  87                                 $this->tables[] = $tables;
  88                         }
  89                 }
  90         }
  91
  92         /**
  93          * Add a set of JOIN conditions to the internal array
  94          *
  95          * JOIN conditions are formatted as array( tablename => array(jointype,
  96          * conditions) e.g. array('page' => array('LEFT JOIN',
  97          * 'page_id=rev_page')) . conditions may be a string or an
  98          * addWhere()-style array
  99          * @param $join_conds array JOIN conditions
 100          */
 101         protected function addJoinConds( $join_conds ) {
 102                 if ( !is_array( $join_conds ) ) {
 103                         ApiBase::dieDebug( __METHOD__, 'Join conditions have to be arrays' );
 104                 }
 105                 $this->join_conds = array_merge( $this->join_conds, $join_conds );
 106         }
 107
 108         /**
 109          * Add a set of fields to select to the internal array
 110          * @param $value array|string Field name or array of field names
 111          */
 112         protected function addFields( $value ) {
 113                 if ( is_array( $value ) ) {
 114                         $this->fields = array_merge( $this->fields, $value );
 115                 } else {
 116                         $this->fields[] = $value;
 117                 }
 118         }
 119
 120         /**
 121          * Same as addFields(), but add the fields only if a condition is met
 122          * @param $value array|string See addFields()
 123          * @param $condition bool If false, do nothing
 124          * @return bool $condition
 125          */
 126         protected function addFieldsIf( $value, $condition ) {
 127                 if ( $condition ) {
 128                         $this->addFields( $value );
 129                         return true;
 130                 }
 131                 return false;
 132         }
 133
 134         /**
 135          * Add a set of WHERE clauses to the internal array.
 136          * Clauses can be formatted as 'foo=bar' or array('foo' => 'bar'),
 137          * the latter only works if the value is a constant (i.e. not another field)
 138          *
 139          * If $value is an empty array, this function does nothing.
 140          *
 141          * For example, array('foo=bar', 'baz' => 3, 'bla' => 'foo') translates
 142          * to "foo=bar AND baz='3' AND bla='foo'"
 143          * @param $value mixed String or array
 144          */
 145         protected function addWhere( $value ) {
 146                 if ( is_array( $value ) ) {
 147                         // Sanity check: don't insert empty arrays,
 148                         // Database::makeList() chokes on them
 149                         if ( count( $value ) ) {
 150                                 $this->where = array_merge( $this->where, $value );
 151                         }
 152                 } else {
 153                         $this->where[] = $value;
 154                 }
 155         }
 156
 157         /**
 158          * Same as addWhere(), but add the WHERE clauses only if a condition is met
 159          * @param $value mixed See addWhere()
 160          * @param $condition bool If false, do nothing
 161          * @return bool $condition
 162          */
 163         protected function addWhereIf( $value, $condition ) {
 164                 if ( $condition ) {
 165                         $this->addWhere( $value );
 166                         return true;
 167                 }
 168                 return false;
 169         }
 170
 171         /**
 172          * Equivalent to addWhere(array($field => $value))
 173          * @param $field string Field name
 174          * @param $value string Value; ignored if null or empty array;
 175          */
 176         protected function addWhereFld( $field, $value ) {
 177                 // Use count() to its full documented capabilities to simultaneously
 178                 // test for null, empty array or empty countable object
 179                 if ( count( $value ) ) {
 180                         $this->where[$field] = $value;
 181                 }
 182         }
 183
 184         /**
 185          * Add a WHERE clause corresponding to a range, and an ORDER BY
 186          * clause to sort in the right direction
 187          * @param $field string Field name
 188          * @param $dir string If 'newer', sort in ascending order, otherwise
 189          *  sort in descending order
 190          * @param $start string Value to start the list at. If $dir == 'newer'
 191          *  this is the lower boundary, otherwise it's the upper boundary
 192          * @param $end string Value to end the list at. If $dir == 'newer' this
 193          *  is the upper boundary, otherwise it's the lower boundary
 194          * @param $sort bool If false, don't add an ORDER BY clause
 195          */
 196         protected function addWhereRange( $field, $dir, $start, $end, $sort = true ) {
 197                 $isDirNewer = ( $dir === 'newer' );
 198                 $after = ( $isDirNewer ? '>=' : '<=' );
 199                 $before = ( $isDirNewer ? '<=' : '>=' );
 200                 $db = $this->getDB();
 201
 202                 if ( !is_null( $start ) ) {
 203                         $this->addWhere( $field . $after . $db->addQuotes( $start ) );
 204                 }
 205
 206                 if ( !is_null( $end ) ) {
 207                         $this->addWhere( $field . $before . $db->addQuotes( $end ) );
 208                 }
 209
 210                 if ( $sort ) {
 211                         $order = $field . ( $isDirNewer ? '' : ' DESC' );
 212                         // Append ORDER BY
 213                         $optionOrderBy = isset( $this->options['ORDER BY'] ) ? (array)$this->options['ORDER BY'] : array();
 214                         $optionOrderBy[] = $order;
 215                         $this->addOption( 'ORDER BY', $optionOrderBy );
 216                 }
 217         }
 218
 219         /**
 220          * Add a WHERE clause corresponding to a range, similar to addWhereRange,
 221          * but converts $start and $end to database timestamps.
 222          * @see addWhereRange
 223          * @param $field
 224          * @param $dir
 225          * @param $start
 226          * @param $end
 227          * @param $sort bool
 228          */
 229         protected function addTimestampWhereRange( $field, $dir, $start, $end, $sort = true ) {
 230                 $db = $this->getDb();
 231                 return $this->addWhereRange( $field, $dir,
 232                         $db->timestampOrNull( $start ), $db->timestampOrNull( $end ), $sort );
 233         }
 234
 235         /**
 236          * Add an option such as LIMIT or USE INDEX. If an option was set
 237          * before, the old value will be overwritten
 238          * @param $name string Option name
 239          * @param $value string Option value
 240          */
 241         protected function addOption( $name, $value = null ) {
 242                 if ( is_null( $value ) ) {
 243                         $this->options[] = $name;
 244                 } else {
 245                         $this->options[$name] = $value;
 246                 }
 247         }
 248
 249         /**
 250          * Execute a SELECT query based on the values in the internal arrays
 251          * @param $method string Function the query should be attributed to.
 252          *  You should usually use __METHOD__ here
 253          * @param $extraQuery array Query data to add but not store in the object
 254          *  Format is array( 'tables' => ..., 'fields' => ..., 'where' => ..., 'options' => ..., 'join_conds' => ... )
 255          * @return ResultWrapper
 256          */
 257         protected function select( $method, $extraQuery = array() ) {
 258
 259                 $tables = array_merge( $this->tables, isset( $extraQuery['tables'] ) ? (array)$extraQuery['tables'] : array() );
 260                 $fields = array_merge( $this->fields, isset( $extraQuery['fields'] ) ? (array)$extraQuery['fields'] : array() );
 261                 $where = array_merge( $this->where, isset( $extraQuery['where'] ) ? (array)$extraQuery['where'] : array() );
 262                 $options = array_merge( $this->options, isset( $extraQuery['options'] ) ? (array)$extraQuery['options'] : array() );
 263                 $join_conds = array_merge( $this->join_conds, isset( $extraQuery['join_conds'] ) ? (array)$extraQuery['join_conds'] : array() );
 264
 265                 // getDB has its own profileDBIn/Out calls
 266                 $db = $this->getDB();
 267
 268                 $this->profileDBIn();
 269                 $res = $db->select( $tables, $fields, $where, $method, $options, $join_conds );
 270                 $this->profileDBOut();
 271
 272                 return $res;
 273         }
 274
 275         /**
 276          * Estimate the row count for the SELECT query that would be run if we
 277          * called select() right now, and check if it's acceptable.
 278          * @return bool true if acceptable, false otherwise
 279          */
 280         protected function checkRowCount() {
 281                 $db = $this->getDB();
 282                 $this->profileDBIn();
 283                 $rowcount = $db->estimateRowCount( $this->tables, $this->fields, $this->where, __METHOD__, $this->options );
 284                 $this->profileDBOut();
 285
 286                 global $wgAPIMaxDBRows;
 287                 if ( $rowcount > $wgAPIMaxDBRows ) {
 288                         return false;
 289                 }
 290                 return true;
 291         }
 292
 293         /**
 294          * Add information (title and namespace) about a Title object to a
 295          * result array
 296          * @param $arr array Result array à la ApiResult
 297          * @param $title Title
 298          * @param $prefix string Module prefix
 299          */
 300         public static function addTitleInfo( &$arr, $title, $prefix = '' ) {
 301                 $arr[$prefix . 'ns'] = intval( $title->getNamespace() );
 302                 $arr[$prefix . 'title'] = $title->getPrefixedText();
 303         }
 304
 305         /**
 306          * Override this method to request extra fields from the pageSet
 307          * using $pageSet->requestField('fieldName')
 308          * @param $pageSet ApiPageSet
 309          */
 310         public function requestExtraData( $pageSet ) {
 311         }
 312
 313         /**
 314          * Get the main Query module
 315          * @return ApiQuery
 316          */
 317         public function getQuery() {
 318                 return $this->mQueryModule;
 319         }
 320
 321         /**
 322          * Add a sub-element under the page element with the given page ID
 323          * @param $pageId int Page ID
 324          * @param $data array Data array à la ApiResult
 325          * @return bool Whether the element fit in the result
 326          */
 327         protected function addPageSubItems( $pageId, $data ) {
 328                 $result = $this->getResult();
 329                 $result->setIndexedTagName( $data, $this->getModulePrefix() );
 330                 return $result->addValue( array( 'query', 'pages', intval( $pageId ) ),
 331                         $this->getModuleName(),
 332                         $data );
 333         }
 334
 335         /**
 336          * Same as addPageSubItems(), but one element of $data at a time
 337          * @param $pageId int Page ID
 338          * @param $item array Data array à la ApiResult
 339          * @param $elemname string XML element name. If null, getModuleName()
 340          *  is used
 341          * @return bool Whether the element fit in the result
 342          */
 343         protected function addPageSubItem( $pageId, $item, $elemname = null ) {
 344                 if ( is_null( $elemname ) ) {
 345                         $elemname = $this->getModulePrefix();
 346                 }
 347                 $result = $this->getResult();
 348                 $fit = $result->addValue( array( 'query', 'pages', $pageId,
 349                                          $this->getModuleName() ), null, $item );
 350                 if ( !$fit ) {
 351                         return false;
 352                 }
 353                 $result->setIndexedTagName_internal( array( 'query', 'pages', $pageId,
 354                                 $this->getModuleName() ), $elemname );
 355                 return true;
 356         }
 357
 358         /**
 359          * Set a query-continue value
 360          * @param $paramName string Parameter name
 361          * @param $paramValue string Parameter value
 362          */
 363         protected function setContinueEnumParameter( $paramName, $paramValue ) {
 364                 $paramName = $this->encodeParamName( $paramName );
 365                 $msg = array( $paramName => $paramValue );
 366                 $result = $this->getResult();
 367                 $result->disableSizeCheck();
 368                 $result->addValue( 'query-continue', $this->getModuleName(), $msg );
 369                 $result->enableSizeCheck();
 370         }
 371
 372         /**
 373          * Get the Query database connection (read-only)
 374          * @return DatabaseBase
 375          */
 376         protected function getDB() {
 377                 if ( is_null( $this->mDb ) ) {
 378                         $apiQuery = $this->getQuery();
 379                         $this->mDb = $apiQuery->getDB();
 380                 }
 381                 return $this->mDb;
 382         }
 383
 384         /**
 385          * Selects the query database connection with the given name.
 386          * See ApiQuery::getNamedDB() for more information
 387          * @param $name string Name to assign to the database connection
 388          * @param $db int One of the DB_* constants
 389          * @param $groups array Query groups
 390          * @return Database
 391          */
 392         public function selectNamedDB( $name, $db, $groups ) {
 393                 $this->mDb = $this->getQuery()->getNamedDB( $name, $db, $groups );
 394         }
 395
 396         /**
 397          * Get the PageSet object to work on
 398          * @return ApiPageSet
 399          */
 400         protected function getPageSet() {
 401                 return $this->getQuery()->getPageSet();
 402         }
 403
 404         /**
 405          * Convert a title to a DB key
 406          * @param $title string Page title with spaces
 407          * @return string Page title with underscores
 408          */
 409         public function titleToKey( $title ) {
 410                 // Don't throw an error if we got an empty string
 411                 if ( trim( $title ) == '' ) {
 412                         return '';
 413                 }
 414                 $t = Title::newFromText( $title );
 415                 if ( !$t ) {
 416                         $this->dieUsageMsg( array( 'invalidtitle', $title ) );
 417                 }
 418                 return $t->getPrefixedDbKey();
 419         }
 420
 421         /**
 422          * The inverse of titleToKey()
 423          * @param $key string Page title with underscores
 424          * @return string Page title with spaces
 425          */
 426         public function keyToTitle( $key ) {
 427                 // Don't throw an error if we got an empty string
 428                 if ( trim( $key ) == '' ) {
 429                         return '';
 430                 }
 431                 $t = Title::newFromDbKey( $key );
 432                 // This really shouldn't happen but we gotta check anyway
 433                 if ( !$t ) {
 434                         $this->dieUsageMsg( array( 'invalidtitle', $key ) );
 435                 }
 436                 return $t->getPrefixedText();
 437         }
 438
 439         /**
 440          * An alternative to titleToKey() that doesn't trim trailing spaces
 441          * @param $titlePart string Title part with spaces
 442          * @return string Title part with underscores
 443          */
 444         public function titlePartToKey( $titlePart ) {
 445                 return substr( $this->titleToKey( $titlePart . 'x' ), 0, - 1 );
 446         }
 447
 448         /**
 449          * An alternative to keyToTitle() that doesn't trim trailing spaces
 450          * @param $keyPart string Key part with spaces
 451          * @return string Key part with underscores
 452          */
 453         public function keyPartToTitle( $keyPart ) {
 454                 return substr( $this->keyToTitle( $keyPart . 'x' ), 0, - 1 );
 455         }
 456
 457         /**
 458          * Gets the personalised direction parameter description
 459          *
 460          * @param string $p ModulePrefix
 461          * @param string $extraDirText Any extra text to be appended on the description
 462          * @return array
 463          */
 464         public function getDirectionDescription( $p = '', $extraDirText = '' ) {
 465                 return array(
 466                                 "In which direction to enumerate{$extraDirText}",
 467                                 " newer          - List oldest first. Note: {$p}start has to be before {$p}end.",
 468                                 " older          - List newest first (default). Note: {$p}start has to be later than {$p}end.",
 469                         );
 470         }
 471
 472         /**
 473          * @param $query String
 474          * @param $protocol String
 475          * @return null|string
 476          */
 477         public function prepareUrlQuerySearchString( $query = null, $protocol = null) {
 478                 $db = $this->getDb();
 479                 if ( !is_null( $query ) || $query != '' ) {
 480                         if ( is_null( $protocol ) ) {
 481                                 $protocol = 'http://';
 482                         }
 483
 484                         $likeQuery = LinkFilter::makeLikeArray( $query, $protocol );
 485                         if ( !$likeQuery ) {
 486                                 $this->dieUsage( 'Invalid query', 'bad_query' );
 487                         }
 488
 489                         $likeQuery = LinkFilter::keepOneWildcard( $likeQuery );
 490                         return 'el_index ' . $db->buildLike( $likeQuery );
 491                 } elseif ( !is_null( $protocol ) ) {
 492                         return 'el_index ' . $db->buildLike( "$protocol", $db->anyString() );
 493                 }
 494
 495                 return null;
 496         }
 497
 498         /**
 499          * Filters hidden users (where the user doesn't have the right to view them)
 500          * Also adds relevant block information
 501          *
 502          * @param bool $showBlockInfo
 503          * @return void
 504          */
 505         public function showHiddenUsersAddBlockInfo( $showBlockInfo ) {
 506                 $userCanViewHiddenUsers = $this->getUser()->isAllowed( 'hideuser' );
 507
 508                 if ( $showBlockInfo || !$userCanViewHiddenUsers ) {
 509                         $this->addTables( 'ipblocks' );
 510                         $this->addJoinConds( array(
 511                                 'ipblocks' => array( 'LEFT JOIN', 'ipb_user=user_id' ),
 512                         ) );
 513
 514                         $this->addFields( 'ipb_deleted' );
 515
 516                         if ( $showBlockInfo ) {
 517                                 $this->addFields( array( 'ipb_reason', 'ipb_by_text', 'ipb_expiry' ) );
 518                         }
 519
 520                         // Don't show hidden names
 521                         if ( !$userCanViewHiddenUsers ) {
 522                                 $this->addWhere( 'ipb_deleted = 0 OR ipb_deleted IS NULL' );
 523                         }
 524                 }
 525         }
 526
 527         /**
 528          * @param $hash string
 529          * @return bool
 530          */
 531         public function validateSha1Hash( $hash ) {
 532                 return preg_match( '/[a-fA-F0-9]{40}/', $hash );
 533         }
 534
 535         /**
 536          * @param $hash string
 537          * @return bool
 538          */
 539         public function validateSha1Base36Hash( $hash ) {
 540                 return preg_match( '/[a-zA-Z0-9]{31}/', $hash );
 541         }
 542
 543         /**
 544          * @return array
 545          */
 546         public function getPossibleErrors() {
 547                 return array_merge( parent::getPossibleErrors(), array(
 548                         array( 'invalidtitle', 'title' ),
 549                         array( 'invalidtitle', 'key' ),
 550                 ) );
 551         }
 552
 553         /**
 554          * Get version string for use in the API help output
 555          * @return string
 556          */
 557         public static function getBaseVersion() {
 558                 return __CLASS__ . ': $Id$';
 559         }
 560 }
 561
 562 /**
 563  * @ingroup API
 564  */
 565 abstract class ApiQueryGeneratorBase extends ApiQueryBase {
 566
 567         private $mIsGenerator;
 568
 569         public function __construct( $query, $moduleName, $paramPrefix = '' ) {
 570                 parent::__construct( $query, $moduleName, $paramPrefix );
 571                 $this->mIsGenerator = false;
 572         }
 573
 574         /**
 575          * Switch this module to generator mode. By default, generator mode is
 576          * switched off and the module acts like a normal query module.
 577          */
 578         public function setGeneratorMode() {
 579                 $this->mIsGenerator = true;
 580         }
 581
 582         /**
 583          * Overrides base class to prepend 'g' to every generator parameter
 584          * @param $paramName string Parameter name
 585          * @return string Prefixed parameter name
 586          */
 587         public function encodeParamName( $paramName ) {
 588                 if ( $this->mIsGenerator ) {
 589                         return 'g' . parent::encodeParamName( $paramName );
 590                 } else {
 591                         return parent::encodeParamName( $paramName );
 592                 }
 593         }
 594
 595         /**
 596          * Execute this module as a generator
 597          * @param $resultPageSet ApiPageSet: All output should be appended to
 598          *  this object
 599          */
 600         public abstract function executeGenerator( $resultPageSet );
 601 }