includes/user/CentralIdLookup.php

   1 <?php
   2 /**
   3  * A central user id lookup service
   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 /**
  24  * The CentralIdLookup service allows for connecting local users with
  25  * cluster-wide IDs.
  26  */
  27 abstract class CentralIdLookup implements IDBAccessObject {
  28         // Audience options for accessors
  29         const AUDIENCE_PUBLIC = 1;
  30         const AUDIENCE_RAW = 2;
  31
  32         /** @var CentralIdLookup[][] */
  33         private static $instances = array();
  34
  35         /** @var string */
  36         private $providerId;
  37
  38         /**
  39          * Fetch a CentralIdLookup
  40          * @param string|null $providerId Provider ID from $wgCentralIdLookupProviders
  41          * @return CentralIdLookup|null
  42          */
  43         public static function factory( $providerId = null ) {
  44                 global $wgCentralIdLookupProviders, $wgCentralIdLookupProvider;
  45
  46                 if ( $providerId === null ) {
  47                         $providerId = $wgCentralIdLookupProvider;
  48                 }
  49
  50                 if ( !array_key_exists( $providerId, self::$instances ) ) {
  51                         self::$instances[$providerId] = null;
  52
  53                         if ( isset( $wgCentralIdLookupProviders[$providerId] ) ) {
  54                                 $provider = ObjectFactory::getObjectFromSpec( $wgCentralIdLookupProviders[$providerId] );
  55                                 if ( $provider instanceof CentralIdLookup ) {
  56                                         $provider->providerId = $providerId;
  57                                         self::$instances[$providerId] = $provider;
  58                                 }
  59                         }
  60                 }
  61
  62                 return self::$instances[$providerId];
  63         }
  64
  65         /**
  66          * Reset internal cache for unit testing
  67          */
  68         public static function resetCache() {
  69                 if ( !defined( 'MW_PHPUNIT_TEST' ) ) {
  70                         throw new MWException( __METHOD__ . ' may only be called from unit tests!' );
  71                 }
  72                 self::$instances = array();
  73         }
  74
  75         final public function getProviderId() {
  76                 return $this->providerId;
  77         }
  78
  79         /**
  80          * Check that the "audience" parameter is valid
  81          * @param int|User $audience One of the audience constants, or a specific user
  82          * @return User|null User to check against, or null if no checks are needed
  83          * @throws InvalidArgumentException
  84          */
  85         protected function checkAudience( $audience ) {
  86                 if ( $audience instanceof User ) {
  87                         return $audience;
  88                 }
  89                 if ( $audience === self::AUDIENCE_PUBLIC ) {
  90                         return new User;
  91                 }
  92                 if ( $audience === self::AUDIENCE_RAW ) {
  93                         return null;
  94                 }
  95                 throw new InvalidArgumentException( 'Invalid audience' );
  96         }
  97
  98         /**
  99          * Check that a User is attached on the specified wiki.
 100          *
 101          * If unattached local accounts don't exist in your extension, this comes
 102          * down to a check whether the central account exists at all and that
 103          * $wikiId is using the same central database.
 104          *
 105          * @param User $user
 106          * @param string|null $wikiId Wiki to check attachment status. If null, check the current wiki.
 107          * @return bool
 108          */
 109         abstract public function isAttached( User $user, $wikiId = null );
 110
 111         /**
 112          * Given central user IDs, return the (local) user names
 113          * @note There's no requirement that the user names actually exist locally,
 114          *  or if they do that they're actually attached to the central account.
 115          * @param array $idToName Array with keys being central user IDs
 116          * @param int|User $audience One of the audience constants, or a specific user
 117          * @param int $flags IDBAccessObject read flags
 118          * @return array Copy of $idToName with values set to user names (or
 119          *  empty-string if the user exists but $audience lacks the rights needed
 120          *  to see it). IDs not corresponding to a user are unchanged.
 121          */
 122         abstract public function lookupCentralIds(
 123                 array $idToName, $audience = self::AUDIENCE_PUBLIC, $flags = self::READ_NORMAL
 124         );
 125
 126         /**
 127          * Given (local) user names, return the central IDs
 128          * @note There's no requirement that the user names actually exist locally,
 129          *  or if they do that they're actually attached to the central account.
 130          * @param array $nameToId Array with keys being canonicalized user names
 131          * @param int|User $audience One of the audience constants, or a specific user
 132          * @param int $flags IDBAccessObject read flags
 133          * @return array Copy of $nameToId with values set to central IDs.
 134          *  Names not corresponding to a user (or $audience lacks the rights needed
 135          *  to see it) are unchanged.
 136          */
 137         abstract public function lookupUserNames(
 138                 array $nameToId, $audience = self::AUDIENCE_PUBLIC, $flags = self::READ_NORMAL
 139         );
 140
 141         /**
 142          * Given a central user ID, return the (local) user name
 143          * @note There's no requirement that the user name actually exists locally,
 144          *  or if it does that it's actually attached to the central account.
 145          * @param int $id Central user ID
 146          * @param int|User $audience One of the audience constants, or a specific user
 147          * @param int $flags IDBAccessObject read flags
 148          * @return string|null User name, or empty string if $audience lacks the
 149          *  rights needed to see it, or null if $id doesn't correspond to a user
 150          */
 151         public function nameFromCentralId(
 152                 $id, $audience = self::AUDIENCE_PUBLIC, $flags = self::READ_NORMAL
 153         ) {
 154                 $idToName = $this->lookupCentralIds( array( $id => null ), $audience, $flags );
 155                 return $idToName[$id];
 156         }
 157
 158         /**
 159          * Given a (local) user name, return the central ID
 160          * @note There's no requirement that the user name actually exists locally,
 161          *  or if it does that it's actually attached to the central account.
 162          * @param string $name Canonicalized user name
 163          * @param int|User $audience One of the audience constants, or a specific user
 164          * @param int $flags IDBAccessObject read flags
 165          * @return int User ID; 0 if the name does not correspond to a user or
 166          *  $audience lacks the rights needed to see it.
 167          */
 168         public function centralIdFromName(
 169                 $name, $audience = self::AUDIENCE_PUBLIC, $flags = self::READ_NORMAL
 170         ) {
 171                 $nameToId = $this->lookupUserNames( array( $name => 0 ), $audience, $flags );
 172                 return $nameToId[$name];
 173         }
 174
 175         /**
 176          * Given a central user ID, return a local User object
 177          * @note Unlike nameFromCentralId(), this does guarantee that the local
 178          *  user exists and is attached to the central account.
 179          * @param int $id Central user ID
 180          * @param int|User $audience One of the audience constants, or a specific user
 181          * @param int $flags IDBAccessObject read flags
 182          * @return User|null Local user, or null if: $id doesn't correspond to a
 183          *  user, $audience lacks the rights needed to see the user, the user
 184          *  doesn't exist locally, or the user isn't locally attached.
 185          */
 186         public function localUserFromCentralId(
 187                 $id, $audience = self::AUDIENCE_PUBLIC, $flags = self::READ_NORMAL
 188         ) {
 189                 $name = $this->nameFromCentralId( $id, $audience, $flags );
 190                 if ( $name !== null && $name !== '' ) {
 191                         $user = User::newFromName( $name );
 192                         if ( $user && $user->getId() && $this->isAttached( $user ) ) {
 193                                 return $user;
 194                         }
 195                 }
 196                 return null;
 197         }
 198
 199         /**
 200          * Given a local User object, return the central ID
 201          * @note Unlike centralIdFromName(), this does guarantee that the local
 202          *  user is attached to the central account.
 203          * @param User $user Local user
 204          * @param int|User $audience One of the audience constants, or a specific user
 205          * @param int $flags IDBAccessObject read flags
 206          * @return int User ID; 0 if the local user does not correspond to a
 207          *  central user, $audience lacks the rights needed to see it, or the
 208          *  central user isn't locally attached.
 209          */
 210         public function centralIdFromLocalUser(
 211                 User $user, $audience = self::AUDIENCE_PUBLIC, $flags = self::READ_NORMAL
 212         ) {
 213                 return $this->isAttached( $user )
 214                         ? $this->centralIdFromName( $user->getName(), $audience, $flags )
 215                         : 0;
 216         }
 217
 218 }