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\IResultWrapper;
  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|array $tables Table name or array of table names
 155          *  or nested arrays for joins using parentheses for grouping
 156          * @param string|null $alias Table alias, or null for no alias. Cannot be
 157          *  used with multiple tables
 158          */
 159         protected function addTables( $tables, $alias = null ) {
 160                 if ( is_array( $tables ) ) {
 161                         if ( $alias !== null ) {
 162                                 ApiBase::dieDebug( __METHOD__, 'Multiple table aliases not supported' );
 163                         }
 164                         $this->tables = array_merge( $this->tables, $tables );
 165                 } elseif ( $alias !== null ) {
 166                         $this->tables[$alias] = $tables;
 167                 } else {
 168                         $this->tables[] = $tables;
 169                 }
 170         }
 171
 172         /**
 173          * Add a set of JOIN conditions to the internal array
 174          *
 175          * JOIN conditions are formatted as [ tablename => [ jointype, conditions ] ]
 176          * e.g. [ 'page' => [ 'LEFT JOIN', 'page_id=rev_page' ] ].
 177          * Conditions may be a string or an addWhere()-style array.
 178          * @param array $join_conds JOIN conditions
 179          */
 180         protected function addJoinConds( $join_conds ) {
 181                 if ( !is_array( $join_conds ) ) {
 182                         ApiBase::dieDebug( __METHOD__, 'Join conditions have to be arrays' );
 183                 }
 184                 $this->join_conds = array_merge( $this->join_conds, $join_conds );
 185         }
 186
 187         /**
 188          * Add a set of fields to select to the internal array
 189          * @param array|string $value Field name or array of field names
 190          */
 191         protected function addFields( $value ) {
 192                 if ( is_array( $value ) ) {
 193                         $this->fields = array_merge( $this->fields, $value );
 194                 } else {
 195                         $this->fields[] = $value;
 196                 }
 197         }
 198
 199         /**
 200          * Same as addFields(), but add the fields only if a condition is met
 201          * @param array|string $value See addFields()
 202          * @param bool $condition If false, do nothing
 203          * @return bool $condition
 204          */
 205         protected function addFieldsIf( $value, $condition ) {
 206                 if ( $condition ) {
 207                         $this->addFields( $value );
 208
 209                         return true;
 210                 }
 211
 212                 return false;
 213         }
 214
 215         /**
 216          * Add a set of WHERE clauses to the internal array.
 217          * Clauses can be formatted as 'foo=bar' or [ 'foo' => 'bar' ],
 218          * the latter only works if the value is a constant (i.e. not another field)
 219          *
 220          * If $value is an empty array, this function does nothing.
 221          *
 222          * For example, [ 'foo=bar', 'baz' => 3, 'bla' => 'foo' ] translates
 223          * to "foo=bar AND baz='3' AND bla='foo'"
 224          * @param string|array $value
 225          */
 226         protected function addWhere( $value ) {
 227                 if ( is_array( $value ) ) {
 228                         // Sanity check: don't insert empty arrays,
 229                         // Database::makeList() chokes on them
 230                         if ( count( $value ) ) {
 231                                 $this->where = array_merge( $this->where, $value );
 232                         }
 233                 } else {
 234                         $this->where[] = $value;
 235                 }
 236         }
 237
 238         /**
 239          * Same as addWhere(), but add the WHERE clauses only if a condition is met
 240          * @param string|array $value
 241          * @param bool $condition If false, do nothing
 242          * @return bool $condition
 243          */
 244         protected function addWhereIf( $value, $condition ) {
 245                 if ( $condition ) {
 246                         $this->addWhere( $value );
 247
 248                         return true;
 249                 }
 250
 251                 return false;
 252         }
 253
 254         /**
 255          * Equivalent to addWhere( [ $field => $value ] )
 256          * @param string $field Field name
 257          * @param string|string[] $value Value; ignored if null or empty array
 258          */
 259         protected function addWhereFld( $field, $value ) {
 260                 if ( $value !== null && !( is_array( $value ) && !$value ) ) {
 261                         $this->where[$field] = $value;
 262                 }
 263         }
 264
 265         /**
 266          * Like addWhereFld for an integer list of IDs
 267          * @since 1.33
 268          * @param string $table Table name
 269          * @param string $field Field name
 270          * @param int[] $ids IDs
 271          * @return int Count of IDs actually included
 272          */
 273         protected function addWhereIDsFld( $table, $field, $ids ) {
 274                 // Use count() to its full documented capabilities to simultaneously
 275                 // test for null, empty array or empty countable object
 276                 if ( count( $ids ) ) {
 277                         $ids = $this->filterIDs( [ [ $table, $field ] ], $ids );
 278
 279                         if ( $ids === [] ) {
 280                                 // Return nothing, no IDs are valid
 281                                 $this->where[] = '0 = 1';
 282                         } else {
 283                                 $this->where[$field] = $ids;
 284                         }
 285                 }
 286                 return count( $ids );
 287         }
 288
 289         /**
 290          * Add a WHERE clause corresponding to a range, and an ORDER BY
 291          * clause to sort in the right direction
 292          * @param string $field Field name
 293          * @param string $dir If 'newer', sort in ascending order, otherwise
 294          *  sort in descending order
 295          * @param string $start Value to start the list at. If $dir == 'newer'
 296          *  this is the lower boundary, otherwise it's the upper boundary
 297          * @param string $end Value to end the list at. If $dir == 'newer' this
 298          *  is the upper boundary, otherwise it's the lower boundary
 299          * @param bool $sort If false, don't add an ORDER BY clause
 300          */
 301         protected function addWhereRange( $field, $dir, $start, $end, $sort = true ) {
 302                 $isDirNewer = ( $dir === 'newer' );
 303                 $after = ( $isDirNewer ? '>=' : '<=' );
 304                 $before = ( $isDirNewer ? '<=' : '>=' );
 305                 $db = $this->getDB();
 306
 307                 if ( !is_null( $start ) ) {
 308                         $this->addWhere( $field . $after . $db->addQuotes( $start ) );
 309                 }
 310
 311                 if ( !is_null( $end ) ) {
 312                         $this->addWhere( $field . $before . $db->addQuotes( $end ) );
 313                 }
 314
 315                 if ( $sort ) {
 316                         $order = $field . ( $isDirNewer ? '' : ' DESC' );
 317                         // Append ORDER BY
 318                         $optionOrderBy = isset( $this->options['ORDER BY'] )
 319                                 ? (array)$this->options['ORDER BY']
 320                                 : [];
 321                         $optionOrderBy[] = $order;
 322                         $this->addOption( 'ORDER BY', $optionOrderBy );
 323                 }
 324         }
 325
 326         /**
 327          * Add a WHERE clause corresponding to a range, similar to addWhereRange,
 328          * but converts $start and $end to database timestamps.
 329          * @see addWhereRange
 330          * @param string $field
 331          * @param string $dir
 332          * @param string $start
 333          * @param string $end
 334          * @param bool $sort
 335          */
 336         protected function addTimestampWhereRange( $field, $dir, $start, $end, $sort = true ) {
 337                 $db = $this->getDB();
 338                 $this->addWhereRange( $field, $dir,
 339                         $db->timestampOrNull( $start ), $db->timestampOrNull( $end ), $sort );
 340         }
 341
 342         /**
 343          * Add an option such as LIMIT or USE INDEX. If an option was set
 344          * before, the old value will be overwritten
 345          * @param string $name Option name
 346          * @param string|string[]|null $value Option value
 347          */
 348         protected function addOption( $name, $value = null ) {
 349                 if ( is_null( $value ) ) {
 350                         $this->options[] = $name;
 351                 } else {
 352                         $this->options[$name] = $value;
 353                 }
 354         }
 355
 356         /**
 357          * Execute a SELECT query based on the values in the internal arrays
 358          * @param string $method Function the query should be attributed to.
 359          *  You should usually use __METHOD__ here
 360          * @param array $extraQuery Query data to add but not store in the object
 361          *  Format is [
 362          *    'tables' => ...,
 363          *    'fields' => ...,
 364          *    'where' => ...,
 365          *    'options' => ...,
 366          *    'join_conds' => ...
 367          *  ]
 368          * @param array|null &$hookData If set, the ApiQueryBaseBeforeQuery and
 369          *  ApiQueryBaseAfterQuery hooks will be called, and the
 370          *  ApiQueryBaseProcessRow hook will be expected.
 371          * @return IResultWrapper
 372          */
 373         protected function select( $method, $extraQuery = [], array &$hookData = null ) {
 374                 $tables = array_merge(
 375                         $this->tables,
 376                         isset( $extraQuery['tables'] ) ? (array)$extraQuery['tables'] : []
 377                 );
 378                 $fields = array_merge(
 379                         $this->fields,
 380                         isset( $extraQuery['fields'] ) ? (array)$extraQuery['fields'] : []
 381                 );
 382                 $where = array_merge(
 383                         $this->where,
 384                         isset( $extraQuery['where'] ) ? (array)$extraQuery['where'] : []
 385                 );
 386                 $options = array_merge(
 387                         $this->options,
 388                         isset( $extraQuery['options'] ) ? (array)$extraQuery['options'] : []
 389                 );
 390                 $join_conds = array_merge(
 391                         $this->join_conds,
 392                         isset( $extraQuery['join_conds'] ) ? (array)$extraQuery['join_conds'] : []
 393                 );
 394
 395                 if ( $hookData !== null ) {
 396                         Hooks::run( 'ApiQueryBaseBeforeQuery',
 397                                 [ $this, &$tables, &$fields, &$where, &$options, &$join_conds, &$hookData ]
 398                         );
 399                 }
 400
 401                 $res = $this->getDB()->select( $tables, $fields, $where, $method, $options, $join_conds );
 402
 403                 if ( $hookData !== null ) {
 404                         Hooks::run( 'ApiQueryBaseAfterQuery', [ $this, $res, &$hookData ] );
 405                 }
 406
 407                 return $res;
 408         }
 409
 410         /**
 411          * Call the ApiQueryBaseProcessRow hook
 412          *
 413          * Generally, a module that passed $hookData to self::select() will call
 414          * this just before calling ApiResult::addValue(), and treat a false return
 415          * here in the same way it treats a false return from addValue().
 416          *
 417          * @since 1.28
 418          * @param object $row Database row
 419          * @param array &$data Data to be added to the result
 420          * @param array &$hookData Hook data from ApiQueryBase::select()
 421          * @return bool Return false if row processing should end with continuation
 422          */
 423         protected function processRow( $row, array &$data, array &$hookData ) {
 424                 return Hooks::run( 'ApiQueryBaseProcessRow', [ $this, $row, &$data, &$hookData ] );
 425         }
 426
 427         /**
 428          * Filters hidden users (where the user doesn't have the right to view them)
 429          * Also adds relevant block information
 430          *
 431          * @param bool $showBlockInfo
 432          * @return void
 433          */
 434         public function showHiddenUsersAddBlockInfo( $showBlockInfo ) {
 435                 $db = $this->getDB();
 436
 437                 $tables = [ 'ipblocks' ];
 438                 $fields = [ 'ipb_deleted' ];
 439                 $joinConds = [
 440                         'blk' => [ 'LEFT JOIN', [
 441                                 'ipb_user=user_id',
 442                                 'ipb_expiry > ' . $db->addQuotes( $db->timestamp() ),
 443                         ] ],
 444                 ];
 445
 446                 if ( $showBlockInfo ) {
 447                         $actorQuery = ActorMigration::newMigration()->getJoin( 'ipb_by' );
 448                         $commentQuery = CommentStore::getStore()->getJoin( 'ipb_reason' );
 449                         $tables += $actorQuery['tables'] + $commentQuery['tables'];
 450                         $joinConds += $actorQuery['joins'] + $commentQuery['joins'];
 451                         $fields = array_merge( $fields, [
 452                                 'ipb_id',
 453                                 'ipb_expiry',
 454                                 'ipb_timestamp'
 455                         ], $actorQuery['fields'], $commentQuery['fields'] );
 456                 }
 457
 458                 $this->addTables( [ 'blk' => $tables ] );
 459                 $this->addFields( $fields );
 460                 $this->addJoinConds( $joinConds );
 461
 462                 // Don't show hidden names
 463                 if ( !$this->getUser()->isAllowed( 'hideuser' ) ) {
 464                         $this->addWhere( 'ipb_deleted = 0 OR ipb_deleted IS NULL' );
 465                 }
 466         }
 467
 468         /**@}*/
 469
 470         /************************************************************************//**
 471          * @name   Utility methods
 472          * @{
 473          */
 474
 475         /**
 476          * Add information (title and namespace) about a Title object to a
 477          * result array
 478          * @param array &$arr Result array à la ApiResult
 479          * @param Title $title
 480          * @param string $prefix Module prefix
 481          */
 482         public static function addTitleInfo( &$arr, $title, $prefix = '' ) {
 483                 $arr[$prefix . 'ns'] = (int)$title->getNamespace();
 484                 $arr[$prefix . 'title'] = $title->getPrefixedText();
 485         }
 486
 487         /**
 488          * Add a sub-element under the page element with the given page ID
 489          * @param int $pageId Page ID
 490          * @param array $data Data array à la ApiResult
 491          * @return bool Whether the element fit in the result
 492          */
 493         protected function addPageSubItems( $pageId, $data ) {
 494                 $result = $this->getResult();
 495                 ApiResult::setIndexedTagName( $data, $this->getModulePrefix() );
 496
 497                 return $result->addValue( [ 'query', 'pages', (int)$pageId ],
 498                         $this->getModuleName(),
 499                         $data );
 500         }
 501
 502         /**
 503          * Same as addPageSubItems(), but one element of $data at a time
 504          * @param int $pageId Page ID
 505          * @param mixed $item Data à la ApiResult
 506          * @param string|null $elemname XML element name. If null, getModuleName()
 507          *  is used
 508          * @return bool Whether the element fit in the result
 509          */
 510         protected function addPageSubItem( $pageId, $item, $elemname = null ) {
 511                 if ( is_null( $elemname ) ) {
 512                         $elemname = $this->getModulePrefix();
 513                 }
 514                 $result = $this->getResult();
 515                 $fit = $result->addValue( [ 'query', 'pages', $pageId,
 516                         $this->getModuleName() ], null, $item );
 517                 if ( !$fit ) {
 518                         return false;
 519                 }
 520                 $result->addIndexedTagName( [ 'query', 'pages', $pageId,
 521                         $this->getModuleName() ], $elemname );
 522
 523                 return true;
 524         }
 525
 526         /**
 527          * Set a query-continue value
 528          * @param string $paramName Parameter name
 529          * @param string|array $paramValue Parameter value
 530          */
 531         protected function setContinueEnumParameter( $paramName, $paramValue ) {
 532                 $this->getContinuationManager()->addContinueParam( $this, $paramName, $paramValue );
 533         }
 534
 535         /**
 536          * Convert an input title or title prefix into a dbkey.
 537          *
 538          * $namespace should always be specified in order to handle per-namespace
 539          * capitalization settings.
 540          *
 541          * @param string $titlePart Title part
 542          * @param int $namespace Namespace of the title
 543          * @return string DBkey (no namespace prefix)
 544          */
 545         public function titlePartToKey( $titlePart, $namespace = NS_MAIN ) {
 546                 $t = Title::makeTitleSafe( $namespace, $titlePart . 'x' );
 547                 if ( !$t || $t->hasFragment() ) {
 548                         // Invalid title (e.g. bad chars) or contained a '#'.
 549                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 550                 }
 551                 if ( $namespace != $t->getNamespace() || $t->isExternal() ) {
 552                         // This can happen in two cases. First, if you call titlePartToKey with a title part
 553                         // that looks like a namespace, but with $defaultNamespace = NS_MAIN. It would be very
 554                         // difficult to handle such a case. Such cases cannot exist and are therefore treated
 555                         // as invalid user input. The second case is when somebody specifies a title interwiki
 556                         // prefix.
 557                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 558                 }
 559
 560                 return substr( $t->getDBkey(), 0, -1 );
 561         }
 562
 563         /**
 564          * Convert an input title or title prefix into a namespace constant and dbkey.
 565          *
 566          * @since 1.26
 567          * @param string $titlePart Title part
 568          * @param int $defaultNamespace Default namespace if none is given
 569          * @return array (int, string) Namespace number and DBkey
 570          */
 571         public function prefixedTitlePartToKey( $titlePart, $defaultNamespace = NS_MAIN ) {
 572                 $t = Title::newFromText( $titlePart . 'x', $defaultNamespace );
 573                 if ( !$t || $t->hasFragment() || $t->isExternal() ) {
 574                         // Invalid title (e.g. bad chars) or contained a '#'.
 575                         $this->dieWithError( [ 'apierror-invalidtitle', wfEscapeWikiText( $titlePart ) ] );
 576                 }
 577
 578                 return [ $t->getNamespace(), substr( $t->getDBkey(), 0, -1 ) ];
 579         }
 580
 581         /**
 582          * @param string $hash
 583          * @return bool
 584          */
 585         public function validateSha1Hash( $hash ) {
 586                 return (bool)preg_match( '/^[a-f0-9]{40}$/', $hash );
 587         }
 588
 589         /**
 590          * @param string $hash
 591          * @return bool
 592          */
 593         public function validateSha1Base36Hash( $hash ) {
 594                 return (bool)preg_match( '/^[a-z0-9]{31}$/', $hash );
 595         }
 596
 597         /**
 598          * Check whether the current user has permission to view revision-deleted
 599          * fields.
 600          * @return bool
 601          */
 602         public function userCanSeeRevDel() {
 603                 return $this->getUser()->isAllowedAny(
 604                         'deletedhistory',
 605                         'deletedtext',
 606                         'suppressrevision',
 607                         'viewsuppressed'
 608                 );
 609         }
 610
 611         /**@}*/
 612 }