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         /**
  39          * @param $query ApiBase
  40          * @param $moduleName string
  41          * @param $paramPrefix string
  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          * @param $params
  59          * @return string
  60          */
  61         public function getCacheMode( $params ) {
  62                 return 'private';
  63         }
  64
  65         /**
  66          * Blank the internal arrays with query parameters
  67          */
  68         protected function resetQueryParams() {
  69                 $this->tables = array();
  70                 $this->where = array();
  71                 $this->fields = array();
  72                 $this->options = array();
  73                 $this->join_conds = array();
  74         }
  75
  76         /**
  77          * Add a set of tables to the internal array
  78          * @param $tables mixed Table name or array of table names
  79          * @param $alias mixed Table alias, or null for no alias. Cannot be
  80          *  used with multiple tables
  81          */
  82         protected function addTables( $tables, $alias = null ) {
  83                 if ( is_array( $tables ) ) {
  84                         if ( !is_null( $alias ) ) {
  85                                 ApiBase::dieDebug( __METHOD__, 'Multiple table aliases not supported' );
  86                         }
  87                         $this->tables = array_merge( $this->tables, $tables );
  88                 } else {
  89                         if ( !is_null( $alias ) ) {
  90                                 $this->tables[$alias] = $tables;
  91                         } else {
  92                                 $this->tables[] = $tables;
  93                         }
  94                 }
  95         }
  96
  97         /**
  98          * Add a set of JOIN conditions to the internal array
  99          *
 100          * JOIN conditions are formatted as array( tablename => array(jointype,
 101          * conditions) e.g. array('page' => array('LEFT JOIN',
 102          * 'page_id=rev_page')) . conditions may be a string or an
 103          * addWhere()-style array
 104          * @param $join_conds array JOIN conditions
 105          */
 106         protected function addJoinConds( $join_conds ) {
 107                 if ( !is_array( $join_conds ) ) {
 108                         ApiBase::dieDebug( __METHOD__, 'Join conditions have to be arrays' );
 109                 }
 110                 $this->join_conds = array_merge( $this->join_conds, $join_conds );
 111         }
 112
 113         /**
 114          * Add a set of fields to select to the internal array
 115          * @param $value array|string Field name or array of field names
 116          */
 117         protected function addFields( $value ) {
 118                 if ( is_array( $value ) ) {
 119                         $this->fields = array_merge( $this->fields, $value );
 120                 } else {
 121                         $this->fields[] = $value;
 122                 }
 123         }
 124
 125         /**
 126          * Same as addFields(), but add the fields only if a condition is met
 127          * @param $value array|string See addFields()
 128          * @param $condition bool If false, do nothing
 129          * @return bool $condition
 130          */
 131         protected function addFieldsIf( $value, $condition ) {
 132                 if ( $condition ) {
 133                         $this->addFields( $value );
 134                         return true;
 135                 }
 136                 return false;
 137         }
 138
 139         /**
 140          * Add a set of WHERE clauses to the internal array.
 141          * Clauses can be formatted as 'foo=bar' or array('foo' => 'bar'),
 142          * the latter only works if the value is a constant (i.e. not another field)
 143          *
 144          * If $value is an empty array, this function does nothing.
 145          *
 146          * For example, array('foo=bar', 'baz' => 3, 'bla' => 'foo') translates
 147          * to "foo=bar AND baz='3' AND bla='foo'"
 148          * @param $value mixed String or array
 149          */
 150         protected function addWhere( $value ) {
 151                 if ( is_array( $value ) ) {
 152                         // Sanity check: don't insert empty arrays,
 153                         // Database::makeList() chokes on them
 154                         if ( count( $value ) ) {
 155                                 $this->where = array_merge( $this->where, $value );
 156                         }
 157                 } else {
 158                         $this->where[] = $value;
 159                 }
 160         }
 161
 162         /**
 163          * Same as addWhere(), but add the WHERE clauses only if a condition is met
 164          * @param $value mixed See addWhere()
 165          * @param $condition bool If false, do nothing
 166          * @return bool $condition
 167          */
 168         protected function addWhereIf( $value, $condition ) {
 169                 if ( $condition ) {
 170                         $this->addWhere( $value );
 171                         return true;
 172                 }
 173                 return false;
 174         }
 175
 176         /**
 177          * Equivalent to addWhere(array($field => $value))
 178          * @param $field string Field name
 179          * @param $value string Value; ignored if null or empty array;
 180          */
 181         protected function addWhereFld( $field, $value ) {
 182                 // Use count() to its full documented capabilities to simultaneously
 183                 // test for null, empty array or empty countable object
 184                 if ( count( $value ) ) {
 185                         $this->where[$field] = $value;
 186                 }
 187         }
 188
 189         /**
 190          * Add a WHERE clause corresponding to a range, and an ORDER BY
 191          * clause to sort in the right direction
 192          * @param $field string Field name
 193          * @param $dir string If 'newer', sort in ascending order, otherwise
 194          *  sort in descending order
 195          * @param $start string Value to start the list at. If $dir == 'newer'
 196          *  this is the lower boundary, otherwise it's the upper boundary
 197          * @param $end string Value to end the list at. If $dir == 'newer' this
 198          *  is the upper boundary, otherwise it's the lower boundary
 199          * @param $sort bool If false, don't add an ORDER BY clause
 200          */
 201         protected function addWhereRange( $field, $dir, $start, $end, $sort = true ) {
 202                 $isDirNewer = ( $dir === 'newer' );
 203                 $after = ( $isDirNewer ? '>=' : '<=' );
 204                 $before = ( $isDirNewer ? '<=' : '>=' );
 205                 $db = $this->getDB();
 206
 207                 if ( !is_null( $start ) ) {
 208                         $this->addWhere( $field . $after . $db->addQuotes( $start ) );
 209                 }
 210
 211                 if ( !is_null( $end ) ) {
 212                         $this->addWhere( $field . $before . $db->addQuotes( $end ) );
 213                 }
 214
 215                 if ( $sort ) {
 216                         $order = $field . ( $isDirNewer ? '' : ' DESC' );
 217                         // Append ORDER BY
 218                         $optionOrderBy = isset( $this->options['ORDER BY'] ) ? (array)$this->options['ORDER BY'] : array();
 219                         $optionOrderBy[] = $order;
 220                         $this->addOption( 'ORDER BY', $optionOrderBy );
 221                 }
 222         }
 223
 224         /**
 225          * Add a WHERE clause corresponding to a range, similar to addWhereRange,
 226          * but converts $start and $end to database timestamps.
 227          * @see addWhereRange
 228          * @param $field
 229          * @param $dir
 230          * @param $start
 231          * @param $end
 232          * @param $sort bool
 233          */
 234         protected function addTimestampWhereRange( $field, $dir, $start, $end, $sort = true ) {
 235                 $db = $this->getDb();
 236                 $this->addWhereRange( $field, $dir,
 237                         $db->timestampOrNull( $start ), $db->timestampOrNull( $end ), $sort );
 238         }
 239
 240         /**
 241          * Add an option such as LIMIT or USE INDEX. If an option was set
 242          * before, the old value will be overwritten
 243          * @param $name string Option name
 244          * @param $value string Option value
 245          */
 246         protected function addOption( $name, $value = null ) {
 247                 if ( is_null( $value ) ) {
 248                         $this->options[] = $name;
 249                 } else {
 250                         $this->options[$name] = $value;
 251                 }
 252         }
 253
 254         /**
 255          * Execute a SELECT query based on the values in the internal arrays
 256          * @param $method string Function the query should be attributed to.
 257          *  You should usually use __METHOD__ here
 258          * @param $extraQuery array Query data to add but not store in the object
 259          *  Format is array( 'tables' => ..., 'fields' => ..., 'where' => ..., 'options' => ..., 'join_conds' => ... )
 260          * @return ResultWrapper
 261          */
 262         protected function select( $method, $extraQuery = array() ) {
 263
 264                 $tables = array_merge( $this->tables, isset( $extraQuery['tables'] ) ? (array)$extraQuery['tables'] : array() );
 265                 $fields = array_merge( $this->fields, isset( $extraQuery['fields'] ) ? (array)$extraQuery['fields'] : array() );
 266                 $where = array_merge( $this->where, isset( $extraQuery['where'] ) ? (array)$extraQuery['where'] : array() );
 267                 $options = array_merge( $this->options, isset( $extraQuery['options'] ) ? (array)$extraQuery['options'] : array() );
 268                 $join_conds = array_merge( $this->join_conds, isset( $extraQuery['join_conds'] ) ? (array)$extraQuery['join_conds'] : array() );
 269
 270                 // getDB has its own profileDBIn/Out calls
 271                 $db = $this->getDB();
 272
 273                 $this->profileDBIn();
 274                 $res = $db->select( $tables, $fields, $where, $method, $options, $join_conds );
 275                 $this->profileDBOut();
 276
 277                 return $res;
 278         }
 279
 280         /**
 281          * Estimate the row count for the SELECT query that would be run if we
 282          * called select() right now, and check if it's acceptable.
 283          * @return bool true if acceptable, false otherwise
 284          */
 285         protected function checkRowCount() {
 286                 $db = $this->getDB();
 287                 $this->profileDBIn();
 288                 $rowcount = $db->estimateRowCount( $this->tables, $this->fields, $this->where, __METHOD__, $this->options );
 289                 $this->profileDBOut();
 290
 291                 global $wgAPIMaxDBRows;
 292                 if ( $rowcount > $wgAPIMaxDBRows ) {
 293                         return false;
 294                 }
 295                 return true;
 296         }
 297
 298         /**
 299          * Add information (title and namespace) about a Title object to a
 300          * result array
 301          * @param $arr array Result array à la ApiResult
 302          * @param $title Title
 303          * @param $prefix string Module prefix
 304          */
 305         public static function addTitleInfo( &$arr, $title, $prefix = '' ) {
 306                 $arr[$prefix . 'ns'] = intval( $title->getNamespace() );
 307                 $arr[$prefix . 'title'] = $title->getPrefixedText();
 308         }
 309
 310         /**
 311          * Override this method to request extra fields from the pageSet
 312          * using $pageSet->requestField('fieldName')
 313          * @param $pageSet ApiPageSet
 314          */
 315         public function requestExtraData( $pageSet ) {
 316         }
 317
 318         /**
 319          * Get the main Query module
 320          * @return ApiQuery
 321          */
 322         public function getQuery() {
 323                 return $this->mQueryModule;
 324         }
 325
 326         /**
 327          * Add a sub-element under the page element with the given page ID
 328          * @param $pageId int Page ID
 329          * @param $data array Data array à la ApiResult
 330          * @return bool Whether the element fit in the result
 331          */
 332         protected function addPageSubItems( $pageId, $data ) {
 333                 $result = $this->getResult();
 334                 $result->setIndexedTagName( $data, $this->getModulePrefix() );
 335                 return $result->addValue( array( 'query', 'pages', intval( $pageId ) ),
 336                         $this->getModuleName(),
 337                         $data );
 338         }
 339
 340         /**
 341          * Same as addPageSubItems(), but one element of $data at a time
 342          * @param $pageId int Page ID
 343          * @param $item array Data array à la ApiResult
 344          * @param $elemname string XML element name. If null, getModuleName()
 345          *  is used
 346          * @return bool Whether the element fit in the result
 347          */
 348         protected function addPageSubItem( $pageId, $item, $elemname = null ) {
 349                 if ( is_null( $elemname ) ) {
 350                         $elemname = $this->getModulePrefix();
 351                 }
 352                 $result = $this->getResult();
 353                 $fit = $result->addValue( array( 'query', 'pages', $pageId,
 354                         $this->getModuleName() ), null, $item );
 355                 if ( !$fit ) {
 356                         return false;
 357                 }
 358                 $result->setIndexedTagName_internal( array( 'query', 'pages', $pageId,
 359                                 $this->getModuleName() ), $elemname );
 360                 return true;
 361         }
 362
 363         /**
 364          * Set a query-continue value
 365          * @param $paramName string Parameter name
 366          * @param $paramValue string Parameter value
 367          */
 368         protected function setContinueEnumParameter( $paramName, $paramValue ) {
 369                 $paramName = $this->encodeParamName( $paramName );
 370                 $msg = array( $paramName => $paramValue );
 371                 $result = $this->getResult();
 372                 $result->disableSizeCheck();
 373                 $result->addValue( 'query-continue', $this->getModuleName(), $msg, ApiResult::ADD_ON_TOP );
 374                 $result->enableSizeCheck();
 375         }
 376
 377         /**
 378          * Get the Query database connection (read-only)
 379          * @return DatabaseBase
 380          */
 381         protected function getDB() {
 382                 if ( is_null( $this->mDb ) ) {
 383                         $this->mDb = $this->getQuery()->getDB();
 384                 }
 385                 return $this->mDb;
 386         }
 387
 388         /**
 389          * Selects the query database connection with the given name.
 390          * See ApiQuery::getNamedDB() for more information
 391          * @param $name string Name to assign to the database connection
 392          * @param $db int One of the DB_* constants
 393          * @param $groups array Query groups
 394          * @return DatabaseBase
 395          */
 396         public function selectNamedDB( $name, $db, $groups ) {
 397                 $this->mDb = $this->getQuery()->getNamedDB( $name, $db, $groups );
 398         }
 399
 400         /**
 401          * Get the PageSet object to work on
 402          * @return ApiPageSet
 403          */
 404         protected function getPageSet() {
 405                 return $this->getQuery()->getPageSet();
 406         }
 407
 408         /**
 409          * Convert a title to a DB key
 410          * @param $title string Page title with spaces
 411          * @return string Page title with underscores
 412          */
 413         public function titleToKey( $title ) {
 414                 // Don't throw an error if we got an empty string
 415                 if ( trim( $title ) == '' ) {
 416                         return '';
 417                 }
 418                 $t = Title::newFromText( $title );
 419                 if ( !$t ) {
 420                         $this->dieUsageMsg( array( 'invalidtitle', $title ) );
 421                 }
 422                 return $t->getPrefixedDbKey();
 423         }
 424
 425         /**
 426          * The inverse of titleToKey()
 427          * @param $key string Page title with underscores
 428          * @return string Page title with spaces
 429          */
 430         public function keyToTitle( $key ) {
 431                 // Don't throw an error if we got an empty string
 432                 if ( trim( $key ) == '' ) {
 433                         return '';
 434                 }
 435                 $t = Title::newFromDbKey( $key );
 436                 // This really shouldn't happen but we gotta check anyway
 437                 if ( !$t ) {
 438                         $this->dieUsageMsg( array( 'invalidtitle', $key ) );
 439                 }
 440                 return $t->getPrefixedText();
 441         }
 442
 443         /**
 444          * An alternative to titleToKey() that doesn't trim trailing spaces
 445          * @param $titlePart string Title part with spaces
 446          * @return string Title part with underscores
 447          */
 448         public function titlePartToKey( $titlePart ) {
 449                 return substr( $this->titleToKey( $titlePart . 'x' ), 0, - 1 );
 450         }
 451
 452         /**
 453          * An alternative to keyToTitle() that doesn't trim trailing spaces
 454          * @param $keyPart string Key part with spaces
 455          * @return string Key part with underscores
 456          */
 457         public function keyPartToTitle( $keyPart ) {
 458                 return substr( $this->keyToTitle( $keyPart . 'x' ), 0, - 1 );
 459         }
 460
 461         /**
 462          * Gets the personalised direction parameter description
 463          *
 464          * @param string $p ModulePrefix
 465          * @param string $extraDirText Any extra text to be appended on the description
 466          * @return array
 467          */
 468         public function getDirectionDescription( $p = '', $extraDirText = '' ) {
 469                 return array(
 470                                 "In which direction to enumerate{$extraDirText}",
 471                                 " newer          - List oldest first. Note: {$p}start has to be before {$p}end.",
 472                                 " older          - List newest first (default). Note: {$p}start has to be later than {$p}end.",
 473                         );
 474         }
 475
 476         /**
 477          * @param $query String
 478          * @param $protocol String
 479          * @return null|string
 480          */
 481         public function prepareUrlQuerySearchString( $query = null, $protocol = null) {
 482                 $db = $this->getDb();
 483                 if ( !is_null( $query ) || $query != '' ) {
 484                         if ( is_null( $protocol ) ) {
 485                                 $protocol = 'http://';
 486                         }
 487
 488                         $likeQuery = LinkFilter::makeLikeArray( $query, $protocol );
 489                         if ( !$likeQuery ) {
 490                                 $this->dieUsage( 'Invalid query', 'bad_query' );
 491                         }
 492
 493                         $likeQuery = LinkFilter::keepOneWildcard( $likeQuery );
 494                         return 'el_index ' . $db->buildLike( $likeQuery );
 495                 } elseif ( !is_null( $protocol ) ) {
 496                         return 'el_index ' . $db->buildLike( "$protocol", $db->anyString() );
 497                 }
 498
 499                 return null;
 500         }
 501
 502         /**
 503          * Filters hidden users (where the user doesn't have the right to view them)
 504          * Also adds relevant block information
 505          *
 506          * @param bool $showBlockInfo
 507          * @return void
 508          */
 509         public function showHiddenUsersAddBlockInfo( $showBlockInfo ) {
 510                 $userCanViewHiddenUsers = $this->getUser()->isAllowed( 'hideuser' );
 511
 512                 if ( $showBlockInfo || !$userCanViewHiddenUsers ) {
 513                         $this->addTables( 'ipblocks' );
 514                         $this->addJoinConds( array(
 515                                 'ipblocks' => array( 'LEFT JOIN', 'ipb_user=user_id' ),
 516                         ) );
 517
 518                         $this->addFields( 'ipb_deleted' );
 519
 520                         if ( $showBlockInfo ) {
 521                                 $this->addFields( array( 'ipb_id', 'ipb_by', 'ipb_by_text', 'ipb_reason', 'ipb_expiry' ) );
 522                         }
 523
 524                         // Don't show hidden names
 525                         if ( !$userCanViewHiddenUsers ) {
 526                                 $this->addWhere( 'ipb_deleted = 0 OR ipb_deleted IS NULL' );
 527                         }
 528                 }
 529         }
 530
 531         /**
 532          * @param $hash string
 533          * @return bool
 534          */
 535         public function validateSha1Hash( $hash ) {
 536                 return preg_match( '/^[a-f0-9]{40}$/', $hash );
 537         }
 538
 539         /**
 540          * @param $hash string
 541          * @return bool
 542          */
 543         public function validateSha1Base36Hash( $hash ) {
 544                 return preg_match( '/^[a-z0-9]{31}$/', $hash );
 545         }
 546
 547         /**
 548          * @return array
 549          */
 550         public function getPossibleErrors() {
 551                 $errors = parent::getPossibleErrors();
 552                 $errors = array_merge( $errors, array(
 553                         array( 'invalidtitle', 'title' ),
 554                         array( 'invalidtitle', 'key' ),
 555                 ) );
 556                 return $errors;
 557         }
 558 }
 559
 560 /**
 561  * @ingroup API
 562  */
 563 abstract class ApiQueryGeneratorBase extends ApiQueryBase {
 564
 565         private $mGeneratorPageSet = null;
 566
 567         /**
 568          * Switch this module to generator mode. By default, generator mode is
 569          * switched off and the module acts like a normal query module.
 570          * @since 1.21 requires pageset parameter
 571          * @param $generatorPageSet ApiPageSet object that the module will get
 572          *        by calling getPageSet() when in generator mode.
 573          */
 574         public function setGeneratorMode( ApiPageSet $generatorPageSet ) {
 575                 if ( $generatorPageSet === null ) {
 576                         ApiBase::dieDebug( __METHOD__, 'Required parameter missing - $generatorPageSet' );
 577                 }
 578                 $this->mGeneratorPageSet = $generatorPageSet;
 579         }
 580
 581         /**
 582          * Get the PageSet object to work on.
 583          * If this module is generator, the pageSet object is different from other module's
 584          * @return ApiPageSet
 585          */
 586         protected function getPageSet() {
 587                 if ( $this->mGeneratorPageSet !== null ) {
 588                         return $this->mGeneratorPageSet;
 589                 }
 590                 return parent::getPageSet();
 591         }
 592
 593         /**
 594          * Overrides base class to prepend 'g' to every generator parameter
 595          * @param $paramName string Parameter name
 596          * @return string Prefixed parameter name
 597          */
 598         public function encodeParamName( $paramName ) {
 599                 if ( $this->mGeneratorPageSet !== null ) {
 600                         return 'g' . parent::encodeParamName( $paramName );
 601                 } else {
 602                         return parent::encodeParamName( $paramName );
 603                 }
 604         }
 605
 606         /**
 607          * Overrides base in case of generator & smart continue to
 608          * notify ApiQueryMain instead of adding them to the result right away.
 609          * @param $paramName string Parameter name
 610          * @param $paramValue string Parameter value
 611          */
 612         protected function setContinueEnumParameter( $paramName, $paramValue ) {
 613                 // If this is a generator and query->setGeneratorContinue() returns false, treat as before
 614                 if ( $this->mGeneratorPageSet === null
 615                         || !$this->getQuery()->setGeneratorContinue( $this, $paramName, $paramValue )
 616                 ) {
 617                         parent::setContinueEnumParameter( $paramName, $paramValue );
 618                 }
 619         }
 620
 621         /**
 622          * Execute this module as a generator
 623          * @param $resultPageSet ApiPageSet: All output should be appended to
 624          *  this object
 625          */
 626         abstract public function executeGenerator( $resultPageSet );
 627 }