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 ApiQuery $queryModule
  40          * @param string $moduleName
  41          * @param string $paramPrefix
  42          */
  43         public function __construct( ApiQuery $queryModule, $moduleName, $paramPrefix = '' ) {
  44                 parent::__construct( $queryModule->getMain(), $moduleName, $paramPrefix );
  45                 $this->mQueryModule = $queryModule;
  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 array $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 string|string[] $tables Table name or array of table names
  79          * @param string|null $alias 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 array $join_conds 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 array|string $value 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 array|string $value See addFields()
 128          * @param bool $condition If false, do nothing
 129          * @return bool $condition
 130          */
 131         protected function addFieldsIf( $value, $condition ) {
 132                 if ( $condition ) {
 133                         $this->addFields( $value );
 134
 135                         return true;
 136                 }
 137
 138                 return false;
 139         }
 140
 141         /**
 142          * Add a set of WHERE clauses to the internal array.
 143          * Clauses can be formatted as 'foo=bar' or array('foo' => 'bar'),
 144          * the latter only works if the value is a constant (i.e. not another field)
 145          *
 146          * If $value is an empty array, this function does nothing.
 147          *
 148          * For example, array('foo=bar', 'baz' => 3, 'bla' => 'foo') translates
 149          * to "foo=bar AND baz='3' AND bla='foo'"
 150          * @param string|array $value
 151          */
 152         protected function addWhere( $value ) {
 153                 if ( is_array( $value ) ) {
 154                         // Sanity check: don't insert empty arrays,
 155                         // Database::makeList() chokes on them
 156                         if ( count( $value ) ) {
 157                                 $this->where = array_merge( $this->where, $value );
 158                         }
 159                 } else {
 160                         $this->where[] = $value;
 161                 }
 162         }
 163
 164         /**
 165          * Same as addWhere(), but add the WHERE clauses only if a condition is met
 166          * @param string|array $value
 167          * @param bool $condition If false, do nothing
 168          * @return bool $condition
 169          */
 170         protected function addWhereIf( $value, $condition ) {
 171                 if ( $condition ) {
 172                         $this->addWhere( $value );
 173
 174                         return true;
 175                 }
 176
 177                 return false;
 178         }
 179
 180         /**
 181          * Equivalent to addWhere(array($field => $value))
 182          * @param string $field Field name
 183          * @param string $value Value; ignored if null or empty array;
 184          */
 185         protected function addWhereFld( $field, $value ) {
 186                 // Use count() to its full documented capabilities to simultaneously
 187                 // test for null, empty array or empty countable object
 188                 if ( count( $value ) ) {
 189                         $this->where[$field] = $value;
 190                 }
 191         }
 192
 193         /**
 194          * Add a WHERE clause corresponding to a range, and an ORDER BY
 195          * clause to sort in the right direction
 196          * @param string $field Field name
 197          * @param string $dir If 'newer', sort in ascending order, otherwise
 198          *  sort in descending order
 199          * @param string $start Value to start the list at. If $dir == 'newer'
 200          *  this is the lower boundary, otherwise it's the upper boundary
 201          * @param string $end Value to end the list at. If $dir == 'newer' this
 202          *  is the upper boundary, otherwise it's the lower boundary
 203          * @param bool $sort If false, don't add an ORDER BY clause
 204          */
 205         protected function addWhereRange( $field, $dir, $start, $end, $sort = true ) {
 206                 $isDirNewer = ( $dir === 'newer' );
 207                 $after = ( $isDirNewer ? '>=' : '<=' );
 208                 $before = ( $isDirNewer ? '<=' : '>=' );
 209                 $db = $this->getDB();
 210
 211                 if ( !is_null( $start ) ) {
 212                         $this->addWhere( $field . $after . $db->addQuotes( $start ) );
 213                 }
 214
 215                 if ( !is_null( $end ) ) {
 216                         $this->addWhere( $field . $before . $db->addQuotes( $end ) );
 217                 }
 218
 219                 if ( $sort ) {
 220                         $order = $field . ( $isDirNewer ? '' : ' DESC' );
 221                         // Append ORDER BY
 222                         $optionOrderBy = isset( $this->options['ORDER BY'] )
 223                                 ? (array)$this->options['ORDER BY']
 224                                 : array();
 225                         $optionOrderBy[] = $order;
 226                         $this->addOption( 'ORDER BY', $optionOrderBy );
 227                 }
 228         }
 229
 230         /**
 231          * Add a WHERE clause corresponding to a range, similar to addWhereRange,
 232          * but converts $start and $end to database timestamps.
 233          * @see addWhereRange
 234          * @param string $field
 235          * @param string $dir
 236          * @param string $start
 237          * @param string $end
 238          * @param bool $sort
 239          */
 240         protected function addTimestampWhereRange( $field, $dir, $start, $end, $sort = true ) {
 241                 $db = $this->getDb();
 242                 $this->addWhereRange( $field, $dir,
 243                         $db->timestampOrNull( $start ), $db->timestampOrNull( $end ), $sort );
 244         }
 245
 246         /**
 247          * Add an option such as LIMIT or USE INDEX. If an option was set
 248          * before, the old value will be overwritten
 249          * @param string $name Option name
 250          * @param string $value Option value
 251          */
 252         protected function addOption( $name, $value = null ) {
 253                 if ( is_null( $value ) ) {
 254                         $this->options[] = $name;
 255                 } else {
 256                         $this->options[$name] = $value;
 257                 }
 258         }
 259
 260         /**
 261          * Execute a SELECT query based on the values in the internal arrays
 262          * @param string $method Function the query should be attributed to.
 263          *  You should usually use __METHOD__ here
 264          * @param array $extraQuery Query data to add but not store in the object
 265          *  Format is array(
 266          *    'tables' => ...,
 267          *    'fields' => ...,
 268          *    'where' => ...,
 269          *    'options' => ...,
 270          *    'join_conds' => ...
 271          *  )
 272          * @return ResultWrapper
 273          */
 274         protected function select( $method, $extraQuery = array() ) {
 275
 276                 $tables = array_merge(
 277                         $this->tables,
 278                         isset( $extraQuery['tables'] ) ? (array)$extraQuery['tables'] : array()
 279                 );
 280                 $fields = array_merge(
 281                         $this->fields,
 282                         isset( $extraQuery['fields'] ) ? (array)$extraQuery['fields'] : array()
 283                 );
 284                 $where = array_merge(
 285                         $this->where,
 286                         isset( $extraQuery['where'] ) ? (array)$extraQuery['where'] : array()
 287                 );
 288                 $options = array_merge(
 289                         $this->options,
 290                         isset( $extraQuery['options'] ) ? (array)$extraQuery['options'] : array()
 291                 );
 292                 $join_conds = array_merge(
 293                         $this->join_conds,
 294                         isset( $extraQuery['join_conds'] ) ? (array)$extraQuery['join_conds'] : array()
 295                 );
 296
 297                 // getDB has its own profileDBIn/Out calls
 298                 $db = $this->getDB();
 299
 300                 $this->profileDBIn();
 301                 $res = $db->select( $tables, $fields, $where, $method, $options, $join_conds );
 302                 $this->profileDBOut();
 303
 304                 return $res;
 305         }
 306
 307         /**
 308          * Estimate the row count for the SELECT query that would be run if we
 309          * called select() right now, and check if it's acceptable.
 310          * @return bool True if acceptable, false otherwise
 311          */
 312         protected function checkRowCount() {
 313                 $db = $this->getDB();
 314                 $this->profileDBIn();
 315                 $rowcount = $db->estimateRowCount(
 316                         $this->tables,
 317                         $this->fields,
 318                         $this->where,
 319                         __METHOD__,
 320                         $this->options
 321                 );
 322                 $this->profileDBOut();
 323
 324                 if ( $rowcount > $this->getConfig()->get( 'APIMaxDBRows' ) ) {
 325                         return false;
 326                 }
 327
 328                 return true;
 329         }
 330
 331         /**
 332          * Add information (title and namespace) about a Title object to a
 333          * result array
 334          * @param array $arr Result array à la ApiResult
 335          * @param Title $title
 336          * @param string $prefix Module prefix
 337          */
 338         public static function addTitleInfo( &$arr, $title, $prefix = '' ) {
 339                 $arr[$prefix . 'ns'] = intval( $title->getNamespace() );
 340                 $arr[$prefix . 'title'] = $title->getPrefixedText();
 341         }
 342
 343         /**
 344          * Override this method to request extra fields from the pageSet
 345          * using $pageSet->requestField('fieldName')
 346          * @param ApiPageSet $pageSet
 347          */
 348         public function requestExtraData( $pageSet ) {
 349         }
 350
 351         /**
 352          * Get the main Query module
 353          * @return ApiQuery
 354          */
 355         public function getQuery() {
 356                 return $this->mQueryModule;
 357         }
 358
 359         /**
 360          * Add a sub-element under the page element with the given page ID
 361          * @param int $pageId Page ID
 362          * @param array $data Data array à la ApiResult
 363          * @return bool Whether the element fit in the result
 364          */
 365         protected function addPageSubItems( $pageId, $data ) {
 366                 $result = $this->getResult();
 367                 $result->setIndexedTagName( $data, $this->getModulePrefix() );
 368
 369                 return $result->addValue( array( 'query', 'pages', intval( $pageId ) ),
 370                         $this->getModuleName(),
 371                         $data );
 372         }
 373
 374         /**
 375          * Same as addPageSubItems(), but one element of $data at a time
 376          * @param int $pageId Page ID
 377          * @param array $item Data array à la ApiResult
 378          * @param string $elemname XML element name. If null, getModuleName()
 379          *  is used
 380          * @return bool Whether the element fit in the result
 381          */
 382         protected function addPageSubItem( $pageId, $item, $elemname = null ) {
 383                 if ( is_null( $elemname ) ) {
 384                         $elemname = $this->getModulePrefix();
 385                 }
 386                 $result = $this->getResult();
 387                 $fit = $result->addValue( array( 'query', 'pages', $pageId,
 388                         $this->getModuleName() ), null, $item );
 389                 if ( !$fit ) {
 390                         return false;
 391                 }
 392                 $result->setIndexedTagName_internal( array( 'query', 'pages', $pageId,
 393                         $this->getModuleName() ), $elemname );
 394
 395                 return true;
 396         }
 397
 398         /**
 399          * Set a query-continue value
 400          * @param string $paramName Parameter name
 401          * @param string|array $paramValue Parameter value
 402          */
 403         protected function setContinueEnumParameter( $paramName, $paramValue ) {
 404                 $this->getResult()->setContinueParam( $this, $paramName, $paramValue );
 405         }
 406
 407         /**
 408          * Get the Query database connection (read-only)
 409          * @return DatabaseBase
 410          */
 411         protected function getDB() {
 412                 if ( is_null( $this->mDb ) ) {
 413                         $this->mDb = $this->getQuery()->getDB();
 414                 }
 415
 416                 return $this->mDb;
 417         }
 418
 419         /**
 420          * Selects the query database connection with the given name.
 421          * See ApiQuery::getNamedDB() for more information
 422          * @param string $name Name to assign to the database connection
 423          * @param int $db One of the DB_* constants
 424          * @param array $groups Query groups
 425          * @return DatabaseBase
 426          */
 427         public function selectNamedDB( $name, $db, $groups ) {
 428                 $this->mDb = $this->getQuery()->getNamedDB( $name, $db, $groups );
 429         }
 430
 431         /**
 432          * Get the PageSet object to work on
 433          * @return ApiPageSet
 434          */
 435         protected function getPageSet() {
 436                 return $this->getQuery()->getPageSet();
 437         }
 438
 439         /**
 440          * Convert a title to a DB key
 441          * @param string $title Page title with spaces
 442          * @return string Page title with underscores
 443          */
 444         public function titleToKey( $title ) {
 445                 // Don't throw an error if we got an empty string
 446                 if ( trim( $title ) == '' ) {
 447                         return '';
 448                 }
 449                 $t = Title::newFromText( $title );
 450                 if ( !$t ) {
 451                         $this->dieUsageMsg( array( 'invalidtitle', $title ) );
 452                 }
 453
 454                 return $t->getPrefixedDBkey();
 455         }
 456
 457         /**
 458          * The inverse of titleToKey()
 459          * @param string $key Page title with underscores
 460          * @return string Page title with spaces
 461          */
 462         public function keyToTitle( $key ) {
 463                 // Don't throw an error if we got an empty string
 464                 if ( trim( $key ) == '' ) {
 465                         return '';
 466                 }
 467                 $t = Title::newFromDBkey( $key );
 468                 // This really shouldn't happen but we gotta check anyway
 469                 if ( !$t ) {
 470                         $this->dieUsageMsg( array( 'invalidtitle', $key ) );
 471                 }
 472
 473                 return $t->getPrefixedText();
 474         }
 475
 476         /**
 477          * An alternative to titleToKey() that doesn't trim trailing spaces, and
 478          * does not mangle the input if starts with something that looks like a
 479          * namespace. It is advisable to pass the namespace parameter in order to
 480          * handle per-namespace capitalization settings.
 481          * @param string $titlePart Title part with spaces
 482          * @param int $defaultNamespace Namespace to assume
 483          * @return string Title part with underscores
 484          */
 485         public function titlePartToKey( $titlePart, $defaultNamespace = NS_MAIN ) {
 486                 $t = Title::makeTitleSafe( $defaultNamespace, $titlePart . 'x' );
 487                 if ( !$t ) {
 488                         $this->dieUsageMsg( array( 'invalidtitle', $titlePart ) );
 489                 }
 490                 if ( $defaultNamespace != $t->getNamespace() || $t->isExternal() ) {
 491                         // This can happen in two cases. First, if you call titlePartToKey with a title part
 492                         // that looks like a namespace, but with $defaultNamespace = NS_MAIN. It would be very
 493                         // difficult to handle such a case. Such cases cannot exist and are therefore treated
 494                         // as invalid user input. The second case is when somebody specifies a title interwiki
 495                         // prefix.
 496                         $this->dieUsageMsg( array( 'invalidtitle', $titlePart ) );
 497                 }
 498
 499                 return substr( $t->getDbKey(), 0, -1 );
 500         }
 501
 502         /**
 503          * An alternative to keyToTitle() that doesn't trim trailing spaces
 504          * @param string $keyPart Key part with spaces
 505          * @return string Key part with underscores
 506          */
 507         public function keyPartToTitle( $keyPart ) {
 508                 return substr( $this->keyToTitle( $keyPart . 'x' ), 0, -1 );
 509         }
 510
 511         /**
 512          * Gets the personalised direction parameter description
 513          *
 514          * @param string $p ModulePrefix
 515          * @param string $extraDirText Any extra text to be appended on the description
 516          * @return array
 517          */
 518         public function getDirectionDescription( $p = '', $extraDirText = '' ) {
 519                 return array(
 520                         "In which direction to enumerate{$extraDirText}",
 521                         " newer          - List oldest first. Note: {$p}start has to be before {$p}end.",
 522                         " older          - List newest first (default). Note: {$p}start has to be later than {$p}end.",
 523                 );
 524         }
 525
 526         /**
 527          * @param string $query
 528          * @param string $protocol
 529          * @return null|string
 530          */
 531         public function prepareUrlQuerySearchString( $query = null, $protocol = null ) {
 532                 $db = $this->getDb();
 533                 if ( !is_null( $query ) || $query != '' ) {
 534                         if ( is_null( $protocol ) ) {
 535                                 $protocol = 'http://';
 536                         }
 537
 538                         $likeQuery = LinkFilter::makeLikeArray( $query, $protocol );
 539                         if ( !$likeQuery ) {
 540                                 $this->dieUsage( 'Invalid query', 'bad_query' );
 541                         }
 542
 543                         $likeQuery = LinkFilter::keepOneWildcard( $likeQuery );
 544
 545                         return 'el_index ' . $db->buildLike( $likeQuery );
 546                 } elseif ( !is_null( $protocol ) ) {
 547                         return 'el_index ' . $db->buildLike( "$protocol", $db->anyString() );
 548                 }
 549
 550                 return null;
 551         }
 552
 553         /**
 554          * Filters hidden users (where the user doesn't have the right to view them)
 555          * Also adds relevant block information
 556          *
 557          * @param bool $showBlockInfo
 558          * @return void
 559          */
 560         public function showHiddenUsersAddBlockInfo( $showBlockInfo ) {
 561                 $this->addTables( 'ipblocks' );
 562                 $this->addJoinConds( array(
 563                         'ipblocks' => array( 'LEFT JOIN', 'ipb_user=user_id' ),
 564                 ) );
 565
 566                 $this->addFields( 'ipb_deleted' );
 567
 568                 if ( $showBlockInfo ) {
 569                         $this->addFields( array( 'ipb_id', 'ipb_by', 'ipb_by_text', 'ipb_reason', 'ipb_expiry' ) );
 570                 }
 571
 572                 // Don't show hidden names
 573                 if ( !$this->getUser()->isAllowed( 'hideuser' ) ) {
 574                         $this->addWhere( 'ipb_deleted = 0 OR ipb_deleted IS NULL' );
 575                 }
 576         }
 577
 578         /**
 579          * @param string $hash
 580          * @return bool
 581          */
 582         public function validateSha1Hash( $hash ) {
 583                 return preg_match( '/^[a-f0-9]{40}$/', $hash );
 584         }
 585
 586         /**
 587          * @param string $hash
 588          * @return bool
 589          */
 590         public function validateSha1Base36Hash( $hash ) {
 591                 return preg_match( '/^[a-z0-9]{31}$/', $hash );
 592         }
 593
 594         /**
 595          * @return array
 596          */
 597         public function getPossibleErrors() {
 598                 $errors = parent::getPossibleErrors();
 599                 $errors = array_merge( $errors, array(
 600                         array( 'invalidtitle', 'title' ),
 601                         array( 'invalidtitle', 'key' ),
 602                 ) );
 603
 604                 return $errors;
 605         }
 606
 607         /**
 608          * Check whether the current user has permission to view revision-deleted
 609          * fields.
 610          * @return bool
 611          */
 612         public function userCanSeeRevDel() {
 613                 return $this->getUser()->isAllowedAny(
 614                         'deletedhistory',
 615                         'deletedtext',
 616                         'suppressrevision',
 617                         'viewsuppressed'
 618                 );
 619         }
 620 }
 621
 622 /**
 623  * @ingroup API
 624  */
 625 abstract class ApiQueryGeneratorBase extends ApiQueryBase {
 626
 627         private $mGeneratorPageSet = null;
 628
 629         /**
 630          * Switch this module to generator mode. By default, generator mode is
 631          * switched off and the module acts like a normal query module.
 632          * @since 1.21 requires pageset parameter
 633          * @param ApiPageSet $generatorPageSet ApiPageSet object that the module will get
 634          *        by calling getPageSet() when in generator mode.
 635          */
 636         public function setGeneratorMode( ApiPageSet $generatorPageSet ) {
 637                 if ( $generatorPageSet === null ) {
 638                         ApiBase::dieDebug( __METHOD__, 'Required parameter missing - $generatorPageSet' );
 639                 }
 640                 $this->mGeneratorPageSet = $generatorPageSet;
 641         }
 642
 643         /**
 644          * Get the PageSet object to work on.
 645          * If this module is generator, the pageSet object is different from other module's
 646          * @return ApiPageSet
 647          */
 648         protected function getPageSet() {
 649                 if ( $this->mGeneratorPageSet !== null ) {
 650                         return $this->mGeneratorPageSet;
 651                 }
 652
 653                 return parent::getPageSet();
 654         }
 655
 656         /**
 657          * Overrides base class to prepend 'g' to every generator parameter
 658          * @param string $paramName Parameter name
 659          * @return string Prefixed parameter name
 660          */
 661         public function encodeParamName( $paramName ) {
 662                 if ( $this->mGeneratorPageSet !== null ) {
 663                         return 'g' . parent::encodeParamName( $paramName );
 664                 } else {
 665                         return parent::encodeParamName( $paramName );
 666                 }
 667         }
 668
 669         /**
 670          * Overridden to set the generator param if in generator mode
 671          * @param string $paramName Parameter name
 672          * @param string|array $paramValue Parameter value
 673          */
 674         protected function setContinueEnumParameter( $paramName, $paramValue ) {
 675                 if ( $this->mGeneratorPageSet !== null ) {
 676                         $this->getResult()->setGeneratorContinueParam( $this, $paramName, $paramValue );
 677                 } else {
 678                         parent::setContinueEnumParameter( $paramName, $paramValue );
 679                 }
 680         }
 681
 682         /**
 683          * Execute this module as a generator
 684          * @param ApiPageSet $resultPageSet All output should be appended to this object
 685          */
 686         abstract public function executeGenerator( $resultPageSet );
 687 }