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 ( $alias !== null ) {
 161                                 ApiBase::dieDebug( __METHOD__, 'Multiple table aliases not supported' );
 162                         }
 163                         $this->tables = array_merge( $this->tables, $tables );
 164                 } elseif ( $alias !== null ) {
 165                         $this->tables[$alias] = $tables;
 166                 } else {
 167                         $this->tables[] = $tables;
 168                 }
 169         }
 170
 171         /**
 172          * Add a set of JOIN conditions to the internal array
 173          *
 174          * JOIN conditions are formatted as [ tablename => [ jointype, conditions ] ]
 175          * e.g. [ 'page' => [ 'LEFT JOIN', 'page_id=rev_page' ] ].
 176          * Conditions may be a string or an addWhere()-style array.
 177          * @param array $join_conds JOIN conditions
 178          */
 179         protected function addJoinConds( $join_conds ) {
 180                 if ( !is_array( $join_conds ) ) {
 181                         ApiBase::dieDebug( __METHOD__, 'Join conditions have to be arrays' );
 182                 }
 183                 $this->join_conds = array_merge( $this->join_conds, $join_conds );
 184         }
 185
 186         /**
 187          * Add a set of fields to select to the internal array
 188          * @param array|string $value Field name or array of field names
 189          */
 190         protected function addFields( $value ) {
 191                 if ( is_array( $value ) ) {
 192                         $this->fields = array_merge( $this->fields, $value );
 193                 } else {
 194                         $this->fields[] = $value;
 195                 }
 196         }
 197
 198         /**
 199          * Same as addFields(), but add the fields only if a condition is met
 200          * @param array|string $value See addFields()
 201          * @param bool $condition If false, do nothing
 202          * @return bool $condition
 203          */
 204         protected function addFieldsIf( $value, $condition ) {
 205                 if ( $condition ) {
 206                         $this->addFields( $value );
 207
 208                         return true;
 209                 }
 210
 211                 return false;
 212         }
 213
 214         /**
 215          * Add a set of WHERE clauses to the internal array.
 216          * Clauses can be formatted as 'foo=bar' or [ 'foo' => 'bar' ],
 217          * the latter only works if the value is a constant (i.e. not another field)
 218          *
 219          * If $value is an empty array, this function does nothing.
 220          *
 221          * For example, [ 'foo=bar', 'baz' => 3, 'bla' => 'foo' ] translates
 222          * to "foo=bar AND baz='3' AND bla='foo'"
 223          * @param string|array $value
 224          */
 225         protected function addWhere( $value ) {
 226                 if ( is_array( $value ) ) {
 227                         // Sanity check: don't insert empty arrays,
 228                         // Database::makeList() chokes on them
 229                         if ( count( $value ) ) {
 230                                 $this->where = array_merge( $this->where, $value );
 231                         }
 232                 } else {
 233                         $this->where[] = $value;
 234                 }
 235         }
 236
 237         /**
 238          * Same as addWhere(), but add the WHERE clauses only if a condition is met
 239          * @param string|array $value
 240          * @param bool $condition If false, do nothing
 241          * @return bool $condition
 242          */
 243         protected function addWhereIf( $value, $condition ) {
 244                 if ( $condition ) {
 245                         $this->addWhere( $value );
 246
 247                         return true;
 248                 }
 249
 250                 return false;
 251         }
 252
 253         /**
 254          * Equivalent to addWhere(array($field => $value))
 255          * @param string $field Field name
 256          * @param string|string[] $value Value; ignored if null or empty array
 257          */
 258         protected function addWhereFld( $field, $value ) {
 259                 if ( $value !== null && !( is_array( $value ) && !$value ) ) {
 260                         $this->where[$field] = $value;
 261                 }
 262         }
 263
 264         /**
 265          * Like addWhereFld for an integer list of IDs
 266          * @since 1.33
 267          * @param string $table Table name
 268          * @param string $field Field name
 269          * @param int[] $ids IDs
 270          * @return int Count of IDs actually included
 271          */
 272         protected function addWhereIDsFld( $table, $field, $ids ) {
 273                 // Use count() to its full documented capabilities to simultaneously
 274                 // test for null, empty array or empty countable object
 275                 if ( count( $ids ) ) {
 276                         $ids = $this->filterIDs( [ [ $table, $field ] ], $ids );
 277
 278                         if ( $ids === [] ) {
 279                                 // Return nothing, no IDs are valid
 280                                 $this->where[] = '0 = 1';
 281                         } else {
 282                                 $this->where[$field] = $ids;
 283                         }
 284                 }
 285                 return count( $ids );
 286         }
 287
 288         /**
 289          * Add a WHERE clause corresponding to a range, and an ORDER BY
 290          * clause to sort in the right direction
 291          * @param string $field Field name
 292          * @param string $dir If 'newer', sort in ascending order, otherwise
 293          *  sort in descending order
 294          * @param string $start Value to start the list at. If $dir == 'newer'
 295          *  this is the lower boundary, otherwise it's the upper boundary
 296          * @param string $end Value to end the list at. If $dir == 'newer' this
 297          *  is the upper boundary, otherwise it's the lower boundary
 298          * @param bool $sort If false, don't add an ORDER BY clause
 299          */
 300         protected function addWhereRange( $field, $dir, $start, $end, $sort = true ) {
 301                 $isDirNewer = ( $dir === 'newer' );
 302                 $after = ( $isDirNewer ? '>=' : '<=' );
 303                 $before = ( $isDirNewer ? '<=' : '>=' );
 304                 $db = $this->getDB();
 305
 306                 if ( !is_null( $start ) ) {
 307                         $this->addWhere( $field . $after . $db->addQuotes( $start ) );
 308                 }
 309
 310                 if ( !is_null( $end ) ) {
 311                         $this->addWhere( $field . $before . $db->addQuotes( $end ) );
 312                 }
 313
 314                 if ( $sort ) {
 315                         $order = $field . ( $isDirNewer ? '' : ' DESC' );
 316                         // Append ORDER BY
 317                         $optionOrderBy = isset( $this->options['ORDER BY'] )
 318                                 ? (array)$this->options['ORDER BY']
 319                                 : [];
 320                         $optionOrderBy[] = $order;
 321                         $this->addOption( 'ORDER BY', $optionOrderBy );
 322                 }
 323         }
 324
 325         /**
 326          * Add a WHERE clause corresponding to a range, similar to addWhereRange,
 327          * but converts $start and $end to database timestamps.
 328          * @see addWhereRange
 329          * @param string $field
 330          * @param string $dir
 331          * @param string $start
 332          * @param string $end
 333          * @param bool $sort
 334          */
 335         protected function addTimestampWhereRange( $field, $dir, $start, $end, $sort = true ) {
 336                 $db = $this->getDB();
 337                 $this->addWhereRange( $field, $dir,
 338                         $db->timestampOrNull( $start ), $db->timestampOrNull( $end ), $sort );
 339         }
 340
 341         /**
 342          * Add an option such as LIMIT or USE INDEX. If an option was set
 343          * before, the old value will be overwritten
 344          * @param string $name Option name
 345          * @param string|string[]|null $value Option value
 346          */
 347         protected function addOption( $name, $value = null ) {
 348                 if ( is_null( $value ) ) {
 349                         $this->options[] = $name;
 350                 } else {
 351                         $this->options[$name] = $value;
 352                 }
 353         }
 354
 355         /**
 356          * Execute a SELECT query based on the values in the internal arrays
 357          * @param string $method Function the query should be attributed to.
 358          *  You should usually use __METHOD__ here
 359          * @param array $extraQuery Query data to add but not store in the object
 360          *  Format is [
 361          *    'tables' => ...,
 362          *    'fields' => ...,
 363          *    'where' => ...,
 364          *    'options' => ...,
 365          *    'join_conds' => ...
 366          *  ]
 367          * @param array|null &$hookData If set, the ApiQueryBaseBeforeQuery and
 368          *  ApiQueryBaseAfterQuery hooks will be called, and the
 369          *  ApiQueryBaseProcessRow hook will be expected.
 370          * @return ResultWrapper
 371          */
 372         protected function select( $method, $extraQuery = [], array &$hookData = null ) {
 373                 $tables = array_merge(
 374                         $this->tables,
 375                         isset( $extraQuery['tables'] ) ? (array)$extraQuery['tables'] : []
 376                 );
 377                 $fields = array_merge(
 378                         $this->fields,
 379                         isset( $extraQuery['fields'] ) ? (array)$extraQuery['fields'] : []
 380                 );
 381                 $where = array_merge(
 382                         $this->where,
 383                         isset( $extraQuery['where'] ) ? (array)$extraQuery['where'] : []
 384                 );
 385                 $options = array_merge(
 386                         $this->options,
 387                         isset( $extraQuery['options'] ) ? (array)$extraQuery['options'] : []
 388                 );
 389                 $join_conds = array_merge(
 390                         $this->join_conds,
 391                         isset( $extraQuery['join_conds'] ) ? (array)$extraQuery['join_conds'] : []
 392                 );
 393
 394                 if ( $hookData !== null ) {
 395                         Hooks::run( 'ApiQueryBaseBeforeQuery',
 396                                 [ $this, &$tables, &$fields, &$where, &$options, &$join_conds, &$hookData ]
 397                         );
 398                 }
 399
 400                 $res = $this->getDB()->select( $tables, $fields, $where, $method, $options, $join_conds );
 401
 402                 if ( $hookData !== null ) {
 403                         Hooks::run( 'ApiQueryBaseAfterQuery', [ $this, $res, &$hookData ] );
 404                 }
 405
 406                 return $res;
 407         }
 408
 409         /**
 410          * Call the ApiQueryBaseProcessRow hook
 411          *
 412          * Generally, a module that passed $hookData to self::select() will call
 413          * this just before calling ApiResult::addValue(), and treat a false return
 414          * here in the same way it treats a false return from addValue().
 415          *
 416          * @since 1.28
 417          * @param object $row Database row
 418          * @param array &$data Data to be added to the result
 419          * @param array &$hookData Hook data from ApiQueryBase::select()
 420          * @return bool Return false if row processing should end with continuation
 421          */
 422         protected function processRow( $row, array &$data, array &$hookData ) {
 423                 return Hooks::run( 'ApiQueryBaseProcessRow', [ $this, $row, &$data, &$hookData ] );
 424         }
 425
 426         /**
 427          * Filters hidden users (where the user doesn't have the right to view them)
 428          * Also adds relevant block information
 429          *
 430          * @param bool $showBlockInfo
 431          * @return void
 432          */
 433         public function showHiddenUsersAddBlockInfo( $showBlockInfo ) {
 434                 $db = $this->getDB();
 435
 436                 $tables = [ 'ipblocks' ];
 437                 $fields = [ 'ipb_deleted' ];
 438                 $joinConds = [
 439                         'blk' => [ 'LEFT JOIN', [
 440                                 'ipb_user=user_id',
 441                                 'ipb_expiry > ' . $db->addQuotes( $db->timestamp() ),
 442                         ] ],
 443                 ];
 444
 445                 if ( $showBlockInfo ) {
 446                         $actorQuery = ActorMigration::newMigration()->getJoin( 'ipb_by' );
 447                         $commentQuery = CommentStore::getStore()->getJoin( 'ipb_reason' );
 448                         $tables += $actorQuery['tables'] + $commentQuery['tables'];
 449                         $joinConds += $actorQuery['joins'] + $commentQuery['joins'];
 450                         $fields = array_merge( $fields, [
 451                                 'ipb_id',
 452                                 'ipb_expiry',
 453                                 'ipb_timestamp'
 454                         ], $actorQuery['fields'], $commentQuery['fields'] );
 455                 }
 456
 457                 $this->addTables( [ 'blk' => $tables ] );
 458                 $this->addFields( $fields );
 459                 $this->addJoinConds( $joinConds );
 460
 461                 // Don't show hidden names
 462                 if ( !$this->getUser()->isAllowed( 'hideuser' ) ) {
 463                         $this->addWhere( 'ipb_deleted = 0 OR ipb_deleted IS NULL' );
 464                 }
 465         }
 466
 467         /**@}*/
 468
 469         /************************************************************************//**
 470          * @name   Utility methods
 471          * @{
 472          */
 473
 474         /**
 475          * Add information (title and namespace) about a Title object to a
 476          * result array
 477          * @param array &$arr Result array à la ApiResult
 478          * @param Title $title
 479          * @param string $prefix Module prefix
 480          */
 481         public static function addTitleInfo( &$arr, $title, $prefix = '' ) {
 482                 $arr[$prefix . 'ns'] = (int)$title->getNamespace();
 483                 $arr[$prefix . 'title'] = $title->getPrefixedText();
 484         }
 485
 486         /**
 487          * Add a sub-element under the page element with the given page ID
 488          * @param int $pageId Page ID
 489          * @param array $data Data array à la ApiResult
 490          * @return bool Whether the element fit in the result
 491          */
 492         protected function addPageSubItems( $pageId, $data ) {
 493                 $result = $this->getResult();
 494                 ApiResult::setIndexedTagName( $data, $this->getModulePrefix() );
 495
 496                 return $result->addValue( [ 'query', 'pages', (int)$pageId ],
 497                         $this->getModuleName(),
 498                         $data );
 499         }
 500
 501         /**
 502          * Same as addPageSubItems(), but one element of $data at a time
 503          * @param int $pageId Page ID
 504          * @param array $item Data array à la ApiResult
 505          * @param string|null $elemname XML element name. If null, getModuleName()
 506          *  is used
 507          * @return bool Whether the element fit in the result
 508          */
 509         protected function addPageSubItem( $pageId, $item, $elemname = null ) {
 510                 if ( is_null( $elemname ) ) {
 511                         $elemname = $this->getModulePrefix();
 512                 }
 513                 $result = $this->getResult();
 514                 $fit = $result->addValue( [ 'query', 'pages', $pageId,
 515                         $this->getModuleName() ], null, $item );
 516                 if ( !$fit ) {
 517                         return false;
 518                 }
 519                 $result->addIndexedTagName( [ 'query', 'pages', $pageId,
 520                         $this->getModuleName() ], $elemname );
 521
 522                 return true;
 523         }
 524
 525         /**
 526          * Set a query-continue value
 527          * @param string $paramName Parameter name
 528          * @param string|array $paramValue Parameter value
 529          */
 530         protected function setContinueEnumParameter( $paramName, $paramValue ) {
 531                 $this->getContinuationManager()->addContinueParam( $this, $paramName, $paramValue );
 532         }
 533
 534         /**
 535          * Convert an input title or title prefix into a dbkey.
 536          *
 537          * $namespace should always be specified in order to handle per-namespace
 538          * capitalization settings.
 539          *
 540          * @param string $titlePart Title part
 541          * @param int $namespace Namespace of the title
 542          * @return string DBkey (no namespace prefix)
 543          */
 544         public function titlePartToKey( $titlePart, $namespace = NS_MAIN ) {
 545                 $t = Title::makeTitleSafe( $namespace, $titlePart . 'x' );
 546                 if ( !$t || $t->hasFragment() ) {
 547                         // Invalid title (e.g. bad chars) or contained a '#'.
 548                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 549                 }
 550                 if ( $namespace != $t->getNamespace() || $t->isExternal() ) {
 551                         // This can happen in two cases. First, if you call titlePartToKey with a title part
 552                         // that looks like a namespace, but with $defaultNamespace = NS_MAIN. It would be very
 553                         // difficult to handle such a case. Such cases cannot exist and are therefore treated
 554                         // as invalid user input. The second case is when somebody specifies a title interwiki
 555                         // prefix.
 556                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 557                 }
 558
 559                 return substr( $t->getDBkey(), 0, -1 );
 560         }
 561
 562         /**
 563          * Convert an input title or title prefix into a namespace constant and dbkey.
 564          *
 565          * @since 1.26
 566          * @param string $titlePart Title part
 567          * @param int $defaultNamespace Default namespace if none is given
 568          * @return array (int, string) Namespace number and DBkey
 569          */
 570         public function prefixedTitlePartToKey( $titlePart, $defaultNamespace = NS_MAIN ) {
 571                 $t = Title::newFromText( $titlePart . 'x', $defaultNamespace );
 572                 if ( !$t || $t->hasFragment() || $t->isExternal() ) {
 573                         // Invalid title (e.g. bad chars) or contained a '#'.
 574                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 575                 }
 576
 577                 return [ $t->getNamespace(), substr( $t->getDBkey(), 0, -1 ) ];
 578         }
 579
 580         /**
 581          * @param string $hash
 582          * @return bool
 583          */
 584         public function validateSha1Hash( $hash ) {
 585                 return (bool)preg_match( '/^[a-f0-9]{40}$/', $hash );
 586         }
 587
 588         /**
 589          * @param string $hash
 590          * @return bool
 591          */
 592         public function validateSha1Base36Hash( $hash ) {
 593                 return (bool)preg_match( '/^[a-z0-9]{31}$/', $hash );
 594         }
 595
 596         /**
 597          * Check whether the current user has permission to view revision-deleted
 598          * fields.
 599          * @return bool
 600          */
 601         public function userCanSeeRevDel() {
 602                 return $this->getUser()->isAllowedAny(
 603                         'deletedhistory',
 604                         'deletedtext',
 605                         'suppressrevision',
 606                         'viewsuppressed'
 607                 );
 608         }
 609
 610         /**@}*/
 611 }