includes/api/ApiQueryBase.php

   1 <?php
   2 /**
   3  * Copyright © 2006 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  */
  22
  23 use Wikimedia\Rdbms\IDatabase;
  24 use Wikimedia\Rdbms\ResultWrapper;
  25
  26 /**
  27  * This is a base class for all Query modules.
  28  * It provides some common functionality such as constructing various SQL
  29  * queries.
  30  *
  31  * @ingroup API
  32  */
  33 abstract class ApiQueryBase extends ApiBase {
  34
  35         private $mQueryModule, $mDb, $tables, $where, $fields, $options, $join_conds;
  36
  37         /**
  38          * @param ApiQuery $queryModule
  39          * @param string $moduleName
  40          * @param string $paramPrefix
  41          */
  42         public function __construct( ApiQuery $queryModule, $moduleName, $paramPrefix = '' ) {
  43                 parent::__construct( $queryModule->getMain(), $moduleName, $paramPrefix );
  44                 $this->mQueryModule = $queryModule;
  45                 $this->mDb = null;
  46                 $this->resetQueryParams();
  47         }
  48
  49         /************************************************************************//**
  50          * @name   Methods to implement
  51          * @{
  52          */
  53
  54         /**
  55          * Get the cache mode for the data generated by this module. Override
  56          * this in the module subclass. For possible return values and other
  57          * details about cache modes, see ApiMain::setCacheMode()
  58          *
  59          * Public caching will only be allowed if *all* the modules that supply
  60          * data for a given request return a cache mode of public.
  61          *
  62          * @param array $params
  63          * @return string
  64          */
  65         public function getCacheMode( $params ) {
  66                 return 'private';
  67         }
  68
  69         /**
  70          * Override this method to request extra fields from the pageSet
  71          * using $pageSet->requestField('fieldName')
  72          *
  73          * Note this only makes sense for 'prop' modules, as 'list' and 'meta'
  74          * modules should not be using the pageset.
  75          *
  76          * @param ApiPageSet $pageSet
  77          */
  78         public function requestExtraData( $pageSet ) {
  79         }
  80
  81         /**@}*/
  82
  83         /************************************************************************//**
  84          * @name   Data access
  85          * @{
  86          */
  87
  88         /**
  89          * Get the main Query module
  90          * @return ApiQuery
  91          */
  92         public function getQuery() {
  93                 return $this->mQueryModule;
  94         }
  95
  96         /** @inheritDoc */
  97         public function getParent() {
  98                 return $this->getQuery();
  99         }
 100
 101         /**
 102          * Get the Query database connection (read-only)
 103          * @return IDatabase
 104          */
 105         protected function getDB() {
 106                 if ( is_null( $this->mDb ) ) {
 107                         $this->mDb = $this->getQuery()->getDB();
 108                 }
 109
 110                 return $this->mDb;
 111         }
 112
 113         /**
 114          * Selects the query database connection with the given name.
 115          * See ApiQuery::getNamedDB() for more information
 116          * @param string $name Name to assign to the database connection
 117          * @param int $db One of the DB_* constants
 118          * @param string|string[] $groups Query groups
 119          * @return IDatabase
 120          */
 121         public function selectNamedDB( $name, $db, $groups ) {
 122                 $this->mDb = $this->getQuery()->getNamedDB( $name, $db, $groups );
 123                 return $this->mDb;
 124         }
 125
 126         /**
 127          * Get the PageSet object to work on
 128          * @return ApiPageSet
 129          */
 130         protected function getPageSet() {
 131                 return $this->getQuery()->getPageSet();
 132         }
 133
 134         /**@}*/
 135
 136         /************************************************************************//**
 137          * @name   Querying
 138          * @{
 139          */
 140
 141         /**
 142          * Blank the internal arrays with query parameters
 143          */
 144         protected function resetQueryParams() {
 145                 $this->tables = [];
 146                 $this->where = [];
 147                 $this->fields = [];
 148                 $this->options = [];
 149                 $this->join_conds = [];
 150         }
 151
 152         /**
 153          * Add a set of tables to the internal array
 154          * @param string|string[] $tables Table name or array of table names
 155          * @param string|null $alias Table alias, or null for no alias. Cannot be
 156          *  used with multiple tables
 157          */
 158         protected function addTables( $tables, $alias = null ) {
 159                 if ( is_array( $tables ) ) {
 160                         if ( !is_null( $alias ) ) {
 161                                 ApiBase::dieDebug( __METHOD__, 'Multiple table aliases not supported' );
 162                         }
 163                         $this->tables = array_merge( $this->tables, $tables );
 164                 } else {
 165                         if ( !is_null( $alias ) ) {
 166                                 $this->tables[$alias] = $tables;
 167                         } else {
 168                                 $this->tables[] = $tables;
 169                         }
 170                 }
 171         }
 172
 173         /**
 174          * Add a set of JOIN conditions to the internal array
 175          *
 176          * JOIN conditions are formatted as [ tablename => [ jointype, conditions ] ]
 177          * e.g. [ 'page' => [ 'LEFT JOIN', 'page_id=rev_page' ] ].
 178          * Conditions may be a string or an addWhere()-style array.
 179          * @param array $join_conds JOIN conditions
 180          */
 181         protected function addJoinConds( $join_conds ) {
 182                 if ( !is_array( $join_conds ) ) {
 183                         ApiBase::dieDebug( __METHOD__, 'Join conditions have to be arrays' );
 184                 }
 185                 $this->join_conds = array_merge( $this->join_conds, $join_conds );
 186         }
 187
 188         /**
 189          * Add a set of fields to select to the internal array
 190          * @param array|string $value Field name or array of field names
 191          */
 192         protected function addFields( $value ) {
 193                 if ( is_array( $value ) ) {
 194                         $this->fields = array_merge( $this->fields, $value );
 195                 } else {
 196                         $this->fields[] = $value;
 197                 }
 198         }
 199
 200         /**
 201          * Same as addFields(), but add the fields only if a condition is met
 202          * @param array|string $value See addFields()
 203          * @param bool $condition If false, do nothing
 204          * @return bool $condition
 205          */
 206         protected function addFieldsIf( $value, $condition ) {
 207                 if ( $condition ) {
 208                         $this->addFields( $value );
 209
 210                         return true;
 211                 }
 212
 213                 return false;
 214         }
 215
 216         /**
 217          * Add a set of WHERE clauses to the internal array.
 218          * Clauses can be formatted as 'foo=bar' or [ 'foo' => 'bar' ],
 219          * the latter only works if the value is a constant (i.e. not another field)
 220          *
 221          * If $value is an empty array, this function does nothing.
 222          *
 223          * For example, [ 'foo=bar', 'baz' => 3, 'bla' => 'foo' ] translates
 224          * to "foo=bar AND baz='3' AND bla='foo'"
 225          * @param string|array $value
 226          */
 227         protected function addWhere( $value ) {
 228                 if ( is_array( $value ) ) {
 229                         // Sanity check: don't insert empty arrays,
 230                         // Database::makeList() chokes on them
 231                         if ( count( $value ) ) {
 232                                 $this->where = array_merge( $this->where, $value );
 233                         }
 234                 } else {
 235                         $this->where[] = $value;
 236                 }
 237         }
 238
 239         /**
 240          * Same as addWhere(), but add the WHERE clauses only if a condition is met
 241          * @param string|array $value
 242          * @param bool $condition If false, do nothing
 243          * @return bool $condition
 244          */
 245         protected function addWhereIf( $value, $condition ) {
 246                 if ( $condition ) {
 247                         $this->addWhere( $value );
 248
 249                         return true;
 250                 }
 251
 252                 return false;
 253         }
 254
 255         /**
 256          * Equivalent to addWhere(array($field => $value))
 257          * @param string $field Field name
 258          * @param string|string[] $value Value; ignored if null or empty array
 259          */
 260         protected function addWhereFld( $field, $value ) {
 261                 if ( $value !== null && !( is_array( $value ) && !$value ) ) {
 262                         $this->where[$field] = $value;
 263                 }
 264         }
 265
 266         /**
 267          * Like addWhereFld for an integer list of IDs
 268          * @since 1.33
 269          * @param string $table Table name
 270          * @param string $field Field name
 271          * @param int[] $ids IDs
 272          * @return int Count of IDs actually included
 273          */
 274         protected function addWhereIDsFld( $table, $field, $ids ) {
 275                 // Use count() to its full documented capabilities to simultaneously
 276                 // test for null, empty array or empty countable object
 277                 if ( count( $ids ) ) {
 278                         $ids = $this->filterIDs( [ [ $table, $field ] ], $ids );
 279
 280                         if ( !count( $ids ) ) {
 281                                 // Return nothing, no IDs are valid
 282                                 $this->where[] = '0 = 1';
 283                         } else {
 284                                 $this->where[$field] = $ids;
 285                         }
 286                 }
 287                 return count( $ids );
 288         }
 289
 290         /**
 291          * Add a WHERE clause corresponding to a range, and an ORDER BY
 292          * clause to sort in the right direction
 293          * @param string $field Field name
 294          * @param string $dir If 'newer', sort in ascending order, otherwise
 295          *  sort in descending order
 296          * @param string $start Value to start the list at. If $dir == 'newer'
 297          *  this is the lower boundary, otherwise it's the upper boundary
 298          * @param string $end Value to end the list at. If $dir == 'newer' this
 299          *  is the upper boundary, otherwise it's the lower boundary
 300          * @param bool $sort If false, don't add an ORDER BY clause
 301          */
 302         protected function addWhereRange( $field, $dir, $start, $end, $sort = true ) {
 303                 $isDirNewer = ( $dir === 'newer' );
 304                 $after = ( $isDirNewer ? '>=' : '<=' );
 305                 $before = ( $isDirNewer ? '<=' : '>=' );
 306                 $db = $this->getDB();
 307
 308                 if ( !is_null( $start ) ) {
 309                         $this->addWhere( $field . $after . $db->addQuotes( $start ) );
 310                 }
 311
 312                 if ( !is_null( $end ) ) {
 313                         $this->addWhere( $field . $before . $db->addQuotes( $end ) );
 314                 }
 315
 316                 if ( $sort ) {
 317                         $order = $field . ( $isDirNewer ? '' : ' DESC' );
 318                         // Append ORDER BY
 319                         $optionOrderBy = isset( $this->options['ORDER BY'] )
 320                                 ? (array)$this->options['ORDER BY']
 321                                 : [];
 322                         $optionOrderBy[] = $order;
 323                         $this->addOption( 'ORDER BY', $optionOrderBy );
 324                 }
 325         }
 326
 327         /**
 328          * Add a WHERE clause corresponding to a range, similar to addWhereRange,
 329          * but converts $start and $end to database timestamps.
 330          * @see addWhereRange
 331          * @param string $field
 332          * @param string $dir
 333          * @param string $start
 334          * @param string $end
 335          * @param bool $sort
 336          */
 337         protected function addTimestampWhereRange( $field, $dir, $start, $end, $sort = true ) {
 338                 $db = $this->getDB();
 339                 $this->addWhereRange( $field, $dir,
 340                         $db->timestampOrNull( $start ), $db->timestampOrNull( $end ), $sort );
 341         }
 342
 343         /**
 344          * Add an option such as LIMIT or USE INDEX. If an option was set
 345          * before, the old value will be overwritten
 346          * @param string $name Option name
 347          * @param string|string[]|null $value Option value
 348          */
 349         protected function addOption( $name, $value = null ) {
 350                 if ( is_null( $value ) ) {
 351                         $this->options[] = $name;
 352                 } else {
 353                         $this->options[$name] = $value;
 354                 }
 355         }
 356
 357         /**
 358          * Execute a SELECT query based on the values in the internal arrays
 359          * @param string $method Function the query should be attributed to.
 360          *  You should usually use __METHOD__ here
 361          * @param array $extraQuery Query data to add but not store in the object
 362          *  Format is [
 363          *    'tables' => ...,
 364          *    'fields' => ...,
 365          *    'where' => ...,
 366          *    'options' => ...,
 367          *    'join_conds' => ...
 368          *  ]
 369          * @param array|null &$hookData If set, the ApiQueryBaseBeforeQuery and
 370          *  ApiQueryBaseAfterQuery hooks will be called, and the
 371          *  ApiQueryBaseProcessRow hook will be expected.
 372          * @return ResultWrapper
 373          */
 374         protected function select( $method, $extraQuery = [], array &$hookData = null ) {
 375                 $tables = array_merge(
 376                         $this->tables,
 377                         isset( $extraQuery['tables'] ) ? (array)$extraQuery['tables'] : []
 378                 );
 379                 $fields = array_merge(
 380                         $this->fields,
 381                         isset( $extraQuery['fields'] ) ? (array)$extraQuery['fields'] : []
 382                 );
 383                 $where = array_merge(
 384                         $this->where,
 385                         isset( $extraQuery['where'] ) ? (array)$extraQuery['where'] : []
 386                 );
 387                 $options = array_merge(
 388                         $this->options,
 389                         isset( $extraQuery['options'] ) ? (array)$extraQuery['options'] : []
 390                 );
 391                 $join_conds = array_merge(
 392                         $this->join_conds,
 393                         isset( $extraQuery['join_conds'] ) ? (array)$extraQuery['join_conds'] : []
 394                 );
 395
 396                 if ( $hookData !== null ) {
 397                         Hooks::run( 'ApiQueryBaseBeforeQuery',
 398                                 [ $this, &$tables, &$fields, &$where, &$options, &$join_conds, &$hookData ]
 399                         );
 400                 }
 401
 402                 $res = $this->getDB()->select( $tables, $fields, $where, $method, $options, $join_conds );
 403
 404                 if ( $hookData !== null ) {
 405                         Hooks::run( 'ApiQueryBaseAfterQuery', [ $this, $res, &$hookData ] );
 406                 }
 407
 408                 return $res;
 409         }
 410
 411         /**
 412          * Call the ApiQueryBaseProcessRow hook
 413          *
 414          * Generally, a module that passed $hookData to self::select() will call
 415          * this just before calling ApiResult::addValue(), and treat a false return
 416          * here in the same way it treats a false return from addValue().
 417          *
 418          * @since 1.28
 419          * @param object $row Database row
 420          * @param array &$data Data to be added to the result
 421          * @param array &$hookData Hook data from ApiQueryBase::select()
 422          * @return bool Return false if row processing should end with continuation
 423          */
 424         protected function processRow( $row, array &$data, array &$hookData ) {
 425                 return Hooks::run( 'ApiQueryBaseProcessRow', [ $this, $row, &$data, &$hookData ] );
 426         }
 427
 428         /**
 429          * @deprecated since 1.33, use LinkFilter::getQueryConditions() instead
 430          * @param string|null $query
 431          * @param string|null $protocol
 432          * @return null|string
 433          */
 434         public function prepareUrlQuerySearchString( $query = null, $protocol = null ) {
 435                 wfDeprecated( __METHOD__, '1.33' );
 436                 $db = $this->getDB();
 437                 if ( $query !== null && $query !== '' ) {
 438                         if ( is_null( $protocol ) ) {
 439                                 $protocol = 'http://';
 440                         }
 441
 442                         $likeQuery = LinkFilter::makeLikeArray( $query, $protocol );
 443                         if ( !$likeQuery ) {
 444                                 $this->dieWithError( 'apierror-badquery' );
 445                         }
 446
 447                         $likeQuery = LinkFilter::keepOneWildcard( $likeQuery );
 448
 449                         return 'el_index ' . $db->buildLike( $likeQuery );
 450                 } elseif ( !is_null( $protocol ) ) {
 451                         return 'el_index ' . $db->buildLike( "$protocol", $db->anyString() );
 452                 }
 453
 454                 return null;
 455         }
 456
 457         /**
 458          * Filters hidden users (where the user doesn't have the right to view them)
 459          * Also adds relevant block information
 460          *
 461          * @param bool $showBlockInfo
 462          * @return void
 463          */
 464         public function showHiddenUsersAddBlockInfo( $showBlockInfo ) {
 465                 $db = $this->getDB();
 466
 467                 $tables = [ 'ipblocks' ];
 468                 $fields = [ 'ipb_deleted' ];
 469                 $joinConds = [
 470                         'blk' => [ 'LEFT JOIN', [
 471                                 'ipb_user=user_id',
 472                                 'ipb_expiry > ' . $db->addQuotes( $db->timestamp() ),
 473                         ] ],
 474                 ];
 475
 476                 if ( $showBlockInfo ) {
 477                         $actorQuery = ActorMigration::newMigration()->getJoin( 'ipb_by' );
 478                         $commentQuery = CommentStore::getStore()->getJoin( 'ipb_reason' );
 479                         $tables += $actorQuery['tables'] + $commentQuery['tables'];
 480                         $joinConds += $actorQuery['joins'] + $commentQuery['joins'];
 481                         $fields = array_merge( $fields, [
 482                                 'ipb_id',
 483                                 'ipb_expiry',
 484                                 'ipb_timestamp'
 485                         ], $actorQuery['fields'], $commentQuery['fields'] );
 486                 }
 487
 488                 $this->addTables( [ 'blk' => $tables ] );
 489                 $this->addFields( $fields );
 490                 $this->addJoinConds( $joinConds );
 491
 492                 // Don't show hidden names
 493                 if ( !$this->getUser()->isAllowed( 'hideuser' ) ) {
 494                         $this->addWhere( 'ipb_deleted = 0 OR ipb_deleted IS NULL' );
 495                 }
 496         }
 497
 498         /**@}*/
 499
 500         /************************************************************************//**
 501          * @name   Utility methods
 502          * @{
 503          */
 504
 505         /**
 506          * Add information (title and namespace) about a Title object to a
 507          * result array
 508          * @param array &$arr Result array à la ApiResult
 509          * @param Title $title
 510          * @param string $prefix Module prefix
 511          */
 512         public static function addTitleInfo( &$arr, $title, $prefix = '' ) {
 513                 $arr[$prefix . 'ns'] = intval( $title->getNamespace() );
 514                 $arr[$prefix . 'title'] = $title->getPrefixedText();
 515         }
 516
 517         /**
 518          * Add a sub-element under the page element with the given page ID
 519          * @param int $pageId Page ID
 520          * @param array $data Data array à la ApiResult
 521          * @return bool Whether the element fit in the result
 522          */
 523         protected function addPageSubItems( $pageId, $data ) {
 524                 $result = $this->getResult();
 525                 ApiResult::setIndexedTagName( $data, $this->getModulePrefix() );
 526
 527                 return $result->addValue( [ 'query', 'pages', intval( $pageId ) ],
 528                         $this->getModuleName(),
 529                         $data );
 530         }
 531
 532         /**
 533          * Same as addPageSubItems(), but one element of $data at a time
 534          * @param int $pageId Page ID
 535          * @param array $item Data array à la ApiResult
 536          * @param string|null $elemname XML element name. If null, getModuleName()
 537          *  is used
 538          * @return bool Whether the element fit in the result
 539          */
 540         protected function addPageSubItem( $pageId, $item, $elemname = null ) {
 541                 if ( is_null( $elemname ) ) {
 542                         $elemname = $this->getModulePrefix();
 543                 }
 544                 $result = $this->getResult();
 545                 $fit = $result->addValue( [ 'query', 'pages', $pageId,
 546                         $this->getModuleName() ], null, $item );
 547                 if ( !$fit ) {
 548                         return false;
 549                 }
 550                 $result->addIndexedTagName( [ 'query', 'pages', $pageId,
 551                         $this->getModuleName() ], $elemname );
 552
 553                 return true;
 554         }
 555
 556         /**
 557          * Set a query-continue value
 558          * @param string $paramName Parameter name
 559          * @param string|array $paramValue Parameter value
 560          */
 561         protected function setContinueEnumParameter( $paramName, $paramValue ) {
 562                 $this->getContinuationManager()->addContinueParam( $this, $paramName, $paramValue );
 563         }
 564
 565         /**
 566          * Convert an input title or title prefix into a dbkey.
 567          *
 568          * $namespace should always be specified in order to handle per-namespace
 569          * capitalization settings.
 570          *
 571          * @param string $titlePart Title part
 572          * @param int $namespace Namespace of the title
 573          * @return string DBkey (no namespace prefix)
 574          */
 575         public function titlePartToKey( $titlePart, $namespace = NS_MAIN ) {
 576                 $t = Title::makeTitleSafe( $namespace, $titlePart . 'x' );
 577                 if ( !$t || $t->hasFragment() ) {
 578                         // Invalid title (e.g. bad chars) or contained a '#'.
 579                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 580                 }
 581                 if ( $namespace != $t->getNamespace() || $t->isExternal() ) {
 582                         // This can happen in two cases. First, if you call titlePartToKey with a title part
 583                         // that looks like a namespace, but with $defaultNamespace = NS_MAIN. It would be very
 584                         // difficult to handle such a case. Such cases cannot exist and are therefore treated
 585                         // as invalid user input. The second case is when somebody specifies a title interwiki
 586                         // prefix.
 587                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 588                 }
 589
 590                 return substr( $t->getDBkey(), 0, -1 );
 591         }
 592
 593         /**
 594          * Convert an input title or title prefix into a namespace constant and dbkey.
 595          *
 596          * @since 1.26
 597          * @param string $titlePart Title part
 598          * @param int $defaultNamespace Default namespace if none is given
 599          * @return array (int, string) Namespace number and DBkey
 600          */
 601         public function prefixedTitlePartToKey( $titlePart, $defaultNamespace = NS_MAIN ) {
 602                 $t = Title::newFromText( $titlePart . 'x', $defaultNamespace );
 603                 if ( !$t || $t->hasFragment() || $t->isExternal() ) {
 604                         // Invalid title (e.g. bad chars) or contained a '#'.
 605                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 606                 }
 607
 608                 return [ $t->getNamespace(), substr( $t->getDBkey(), 0, -1 ) ];
 609         }
 610
 611         /**
 612          * @param string $hash
 613          * @return bool
 614          */
 615         public function validateSha1Hash( $hash ) {
 616                 return (bool)preg_match( '/^[a-f0-9]{40}$/', $hash );
 617         }
 618
 619         /**
 620          * @param string $hash
 621          * @return bool
 622          */
 623         public function validateSha1Base36Hash( $hash ) {
 624                 return (bool)preg_match( '/^[a-z0-9]{31}$/', $hash );
 625         }
 626
 627         /**
 628          * Check whether the current user has permission to view revision-deleted
 629          * fields.
 630          * @return bool
 631          */
 632         public function userCanSeeRevDel() {
 633                 return $this->getUser()->isAllowedAny(
 634                         'deletedhistory',
 635                         'deletedtext',
 636                         'suppressrevision',
 637                         'viewsuppressed'
 638                 );
 639         }
 640
 641         /**@}*/
 642 }