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          * Add a WHERE clause corresponding to a range, similar to addWhereRange,
 225          * but converts $start and $end to database timestamps.
 226          * @see addWhereRange
 227          */
 228         protected function addTimestampWhereRange( $field, $dir, $start, $end, $sort = true ) {
 229                 $db = $this->getDb();
 230                 return $this->addWhereRange( $field, $dir,
 231                         $db->timestampOrNull( $start ), $db->timestampOrNull( $end ), $sort );
 232         }
 233
 234         /**
 235          * Add an option such as LIMIT or USE INDEX. If an option was set
 236          * before, the old value will be overwritten
 237          * @param $name string Option name
 238          * @param $value string Option value
 239          */
 240         protected function addOption( $name, $value = null ) {
 241                 if ( is_null( $value ) ) {
 242                         $this->options[] = $name;
 243                 } else {
 244                         $this->options[$name] = $value;
 245                 }
 246         }
 247
 248         /**
 249          * Execute a SELECT query based on the values in the internal arrays
 250          * @param $method string Function the query should be attributed to.
 251          *  You should usually use __METHOD__ here
 252          * @param $extraQuery array Query data to add but not store in the object
 253          *  Format is array( 'tables' => ..., 'fields' => ..., 'where' => ..., 'options' => ..., 'join_conds' => ... )
 254          * @return ResultWrapper
 255          */
 256         protected function select( $method, $extraQuery = array() ) {
 257
 258                 $tables = array_merge( $this->tables, isset( $extraQuery['tables'] ) ? (array)$extraQuery['tables'] : array() );
 259                 $fields = array_merge( $this->fields, isset( $extraQuery['fields'] ) ? (array)$extraQuery['fields'] : array() );
 260                 $where = array_merge( $this->where, isset( $extraQuery['where'] ) ? (array)$extraQuery['where'] : array() );
 261                 $options = array_merge( $this->options, isset( $extraQuery['options'] ) ? (array)$extraQuery['options'] : array() );
 262                 $join_conds = array_merge( $this->join_conds, isset( $extraQuery['join_conds'] ) ? (array)$extraQuery['join_conds'] : array() );
 263
 264                 // getDB has its own profileDBIn/Out calls
 265                 $db = $this->getDB();
 266
 267                 $this->profileDBIn();
 268                 $res = $db->select( $tables, $fields, $where, $method, $options, $join_conds );
 269                 $this->profileDBOut();
 270
 271                 return $res;
 272         }
 273
 274         /**
 275          * Estimate the row count for the SELECT query that would be run if we
 276          * called select() right now, and check if it's acceptable.
 277          * @return bool true if acceptable, false otherwise
 278          */
 279         protected function checkRowCount() {
 280                 $db = $this->getDB();
 281                 $this->profileDBIn();
 282                 $rowcount = $db->estimateRowCount( $this->tables, $this->fields, $this->where, __METHOD__, $this->options );
 283                 $this->profileDBOut();
 284
 285                 global $wgAPIMaxDBRows;
 286                 if ( $rowcount > $wgAPIMaxDBRows ) {
 287                         return false;
 288                 }
 289                 return true;
 290         }
 291
 292         /**
 293          * Add information (title and namespace) about a Title object to a
 294          * result array
 295          * @param $arr array Result array à la ApiResult
 296          * @param $title Title
 297          * @param $prefix string Module prefix
 298          */
 299         public static function addTitleInfo( &$arr, $title, $prefix = '' ) {
 300                 $arr[$prefix . 'ns'] = intval( $title->getNamespace() );
 301                 $arr[$prefix . 'title'] = $title->getPrefixedText();
 302         }
 303
 304         /**
 305          * Override this method to request extra fields from the pageSet
 306          * using $pageSet->requestField('fieldName')
 307          * @param $pageSet ApiPageSet
 308          */
 309         public function requestExtraData( $pageSet ) {
 310         }
 311
 312         /**
 313          * Get the main Query module
 314          * @return ApiQuery
 315          */
 316         public function getQuery() {
 317                 return $this->mQueryModule;
 318         }
 319
 320         /**
 321          * Add a sub-element under the page element with the given page ID
 322          * @param $pageId int Page ID
 323          * @param $data array Data array à la ApiResult
 324          * @return bool Whether the element fit in the result
 325          */
 326         protected function addPageSubItems( $pageId, $data ) {
 327                 $result = $this->getResult();
 328                 $result->setIndexedTagName( $data, $this->getModulePrefix() );
 329                 return $result->addValue( array( 'query', 'pages', intval( $pageId ) ),
 330                         $this->getModuleName(),
 331                         $data );
 332         }
 333
 334         /**
 335          * Same as addPageSubItems(), but one element of $data at a time
 336          * @param $pageId int Page ID
 337          * @param $item array Data array à la ApiResult
 338          * @param $elemname string XML element name. If null, getModuleName()
 339          *  is used
 340          * @return bool Whether the element fit in the result
 341          */
 342         protected function addPageSubItem( $pageId, $item, $elemname = null ) {
 343                 if ( is_null( $elemname ) ) {
 344                         $elemname = $this->getModulePrefix();
 345                 }
 346                 $result = $this->getResult();
 347                 $fit = $result->addValue( array( 'query', 'pages', $pageId,
 348                                          $this->getModuleName() ), null, $item );
 349                 if ( !$fit ) {
 350                         return false;
 351                 }
 352                 $result->setIndexedTagName_internal( array( 'query', 'pages', $pageId,
 353                                 $this->getModuleName() ), $elemname );
 354                 return true;
 355         }
 356
 357         /**
 358          * Set a query-continue value
 359          * @param $paramName string Parameter name
 360          * @param $paramValue string Parameter value
 361          */
 362         protected function setContinueEnumParameter( $paramName, $paramValue ) {
 363                 $paramName = $this->encodeParamName( $paramName );
 364                 $msg = array( $paramName => $paramValue );
 365                 $result = $this->getResult();
 366                 $result->disableSizeCheck();
 367                 $result->addValue( 'query-continue', $this->getModuleName(), $msg );
 368                 $result->enableSizeCheck();
 369         }
 370
 371         /**
 372          * Get the Query database connection (read-only)
 373          * @return DatabaseBase
 374          */
 375         protected function getDB() {
 376                 if ( is_null( $this->mDb ) ) {
 377                         $apiQuery = $this->getQuery();
 378                         $this->mDb = $apiQuery->getDB();
 379                 }
 380                 return $this->mDb;
 381         }
 382
 383         /**
 384          * Selects the query database connection with the given name.
 385          * See ApiQuery::getNamedDB() for more information
 386          * @param $name string Name to assign to the database connection
 387          * @param $db int One of the DB_* constants
 388          * @param $groups array Query groups
 389          * @return Database
 390          */
 391         public function selectNamedDB( $name, $db, $groups ) {
 392                 $this->mDb = $this->getQuery()->getNamedDB( $name, $db, $groups );
 393         }
 394
 395         /**
 396          * Get the PageSet object to work on
 397          * @return ApiPageSet
 398          */
 399         protected function getPageSet() {
 400                 return $this->getQuery()->getPageSet();
 401         }
 402
 403         /**
 404          * Convert a title to a DB key
 405          * @param $title string Page title with spaces
 406          * @return string Page title with underscores
 407          */
 408         public function titleToKey( $title ) {
 409                 // Don't throw an error if we got an empty string
 410                 if ( trim( $title ) == '' ) {
 411                         return '';
 412                 }
 413                 $t = Title::newFromText( $title );
 414                 if ( !$t ) {
 415                         $this->dieUsageMsg( array( 'invalidtitle', $title ) );
 416                 }
 417                 return $t->getPrefixedDbKey();
 418         }
 419
 420         /**
 421          * The inverse of titleToKey()
 422          * @param $key string Page title with underscores
 423          * @return string Page title with spaces
 424          */
 425         public function keyToTitle( $key ) {
 426                 // Don't throw an error if we got an empty string
 427                 if ( trim( $key ) == '' ) {
 428                         return '';
 429                 }
 430                 $t = Title::newFromDbKey( $key );
 431                 // This really shouldn't happen but we gotta check anyway
 432                 if ( !$t ) {
 433                         $this->dieUsageMsg( array( 'invalidtitle', $key ) );
 434                 }
 435                 return $t->getPrefixedText();
 436         }
 437
 438         /**
 439          * An alternative to titleToKey() that doesn't trim trailing spaces
 440          * @param $titlePart string Title part with spaces
 441          * @return string Title part with underscores
 442          */
 443         public function titlePartToKey( $titlePart ) {
 444                 return substr( $this->titleToKey( $titlePart . 'x' ), 0, - 1 );
 445         }
 446
 447         /**
 448          * An alternative to keyToTitle() that doesn't trim trailing spaces
 449          * @param $keyPart string Key part with spaces
 450          * @return string Key part with underscores
 451          */
 452         public function keyPartToTitle( $keyPart ) {
 453                 return substr( $this->keyToTitle( $keyPart . 'x' ), 0, - 1 );
 454         }
 455
 456         /**
 457          * Gets the personalised direction parameter description
 458          *
 459          * @param string $p ModulePrefix
 460          * @param string $extraDirText Any extra text to be appended on the description
 461          * @return array
 462          */
 463         public function getDirectionDescription( $p = '', $extraDirText = '' ) {
 464                 return array(
 465                                 "In which direction to enumerate{$extraDirText}",
 466                                 " newer          - List oldest first. Note: {$p}start has to be before {$p}end.",
 467                                 " older          - List newest first (default). Note: {$p}start has to be later than {$p}end.",
 468                         );
 469         }
 470
 471         /**
 472          * @param $query String
 473          * @param $protocol String
 474          * @return null|string
 475          */
 476         public function prepareUrlQuerySearchString( $query = null, $protocol = null) {
 477                 $db = $this->getDb();
 478                 if ( !is_null( $query ) || $query != '' ) {
 479                         if ( is_null( $protocol ) ) {
 480                                 $protocol = 'http://';
 481                         }
 482
 483                         $likeQuery = LinkFilter::makeLikeArray( $query, $protocol );
 484                         if ( !$likeQuery ) {
 485                                 $this->dieUsage( 'Invalid query', 'bad_query' );
 486                         }
 487
 488                         $likeQuery = LinkFilter::keepOneWildcard( $likeQuery );
 489                         return 'el_index ' . $db->buildLike( $likeQuery );
 490                 } elseif ( !is_null( $protocol ) ) {
 491                         return 'el_index ' . $db->buildLike( "$protocol", $db->anyString() );
 492                 }
 493
 494                 return null;
 495         }
 496
 497         /**
 498          * Filters hidden users (where the user doesn't have the right to view them)
 499          * Also adds relevant block information
 500          *
 501          * @param bool $showBlockInfo
 502          * @return void
 503          */
 504         public function showHiddenUsersAddBlockInfo( $showBlockInfo ) {
 505                 $userCanViewHiddenUsers = $this->getUser()->isAllowed( 'hideuser' );
 506
 507                 if ( $showBlockInfo || !$userCanViewHiddenUsers ) {
 508                         $this->addTables( 'ipblocks' );
 509                         $this->addJoinConds( array(
 510                                 'ipblocks' => array( 'LEFT JOIN', 'ipb_user=user_id' ),
 511                         ) );
 512
 513                         $this->addFields( 'ipb_deleted' );
 514
 515                         if ( $showBlockInfo ) {
 516                                 $this->addFields( array( 'ipb_reason', 'ipb_by_text', 'ipb_expiry' ) );
 517                         }
 518
 519                         // Don't show hidden names
 520                         if ( !$userCanViewHiddenUsers ) {
 521                                 $this->addWhere( 'ipb_deleted = 0 OR ipb_deleted IS NULL' );
 522                         }
 523                 }
 524         }
 525
 526         /**
 527          * @param $hash string
 528          * @return bool
 529          */
 530         public function validateSha1Hash( $hash ) {
 531                 return preg_match( '/[a-fA-F0-9]{40}/', $hash );
 532         }
 533
 534         /**
 535          * @param $hash string
 536          * @return bool
 537          */
 538         public function validateSha1Base36Hash( $hash ) {
 539                 return preg_match( '/[a-zA-Z0-9]{31}/', $hash );
 540         }
 541
 542         /**
 543          * @return array
 544          */
 545         public function getPossibleErrors() {
 546                 return array_merge( parent::getPossibleErrors(), array(
 547                         array( 'invalidtitle', 'title' ),
 548                         array( 'invalidtitle', 'key' ),
 549                 ) );
 550         }
 551
 552         /**
 553          * Get version string for use in the API help output
 554          * @return string
 555          */
 556         public static function getBaseVersion() {
 557                 return __CLASS__ . ': $Id$';
 558         }
 559 }
 560
 561 /**
 562  * @ingroup API
 563  */
 564 abstract class ApiQueryGeneratorBase extends ApiQueryBase {
 565
 566         private $mIsGenerator;
 567
 568         public function __construct( $query, $moduleName, $paramPrefix = '' ) {
 569                 parent::__construct( $query, $moduleName, $paramPrefix );
 570                 $this->mIsGenerator = false;
 571         }
 572
 573         /**
 574          * Switch this module to generator mode. By default, generator mode is
 575          * switched off and the module acts like a normal query module.
 576          */
 577         public function setGeneratorMode() {
 578                 $this->mIsGenerator = true;
 579         }
 580
 581         /**
 582          * Overrides base class to prepend 'g' to every generator parameter
 583          * @param $paramName string Parameter name
 584          * @return string Prefixed parameter name
 585          */
 586         public function encodeParamName( $paramName ) {
 587                 if ( $this->mIsGenerator ) {
 588                         return 'g' . parent::encodeParamName( $paramName );
 589                 } else {
 590                         return parent::encodeParamName( $paramName );
 591                 }
 592         }
 593
 594         /**
 595          * Execute this module as a generator
 596          * @param $resultPageSet ApiPageSet: All output should be appended to
 597          *  this object
 598          */
 599         public abstract function executeGenerator( $resultPageSet );
 600 }