includes/SiteConfiguration.php

   1 <?php
   2 /**
   3  * Configuration holder, particularly for multi-wiki sites.
   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  * This is a class for holding configuration settings, particularly for
  25  * multi-wiki sites.
  26  *
  27  * A basic synopsis:
  28  *
  29  * Consider a wikifarm having three sites: two production sites, one in English
  30  * and one in German, and one testing site. You can assign them easy-to-remember
  31  * identifiers - ISO 639 codes 'en' and 'de' for language wikis, and 'beta' for
  32  * the testing wiki.
  33  *
  34  * You would thus initialize the site configuration by specifying the wiki
  35  * identifiers:
  36  *
  37  * @code
  38  * $conf = new SiteConfiguration;
  39  * $conf->wikis = array( 'de', 'en', 'beta' );
  40  * @endcode
  41  *
  42  * When configuring the MediaWiki global settings (the $wg variables),
  43  * the identifiers will be available to specify settings on a per wiki basis.
  44  *
  45  * @code
  46  * $conf->settings = array(
  47  *      'wgSomeSetting' => array(
  48  *
  49  *              # production:
  50  *              'de'     => false,
  51  *              'en'     => false,
  52  *
  53  *              # test:
  54  *              'beta    => true,
  55  *      ),
  56  * );
  57  * @endcode
  58  *
  59  * With three wikis, that is easy to manage. But what about a farm with
  60  * hundreds of wikis? Site configuration provides a special keyword named
  61  * 'default' which is the value used when a wiki is not found. Hence
  62  * the above code could be written:
  63  *
  64  * @code
  65  * $conf->settings = array(
  66  *      'wgSomeSetting' => array(
  67  *
  68  *              'default' => false,
  69  *
  70  *              # Enable feature on test
  71  *              'beta'    => true,
  72  *      ),
  73  * );
  74  * @endcode
  75  *
  76  *
  77  * Since settings can contain arrays, site configuration provides a way
  78  * to merge an array with the default. This is very useful to avoid
  79  * repeating settings again and again while still maintaining specific changes
  80  * on a per wiki basis.
  81  *
  82  * @code
  83  * $conf->settings = array(
  84  *      'wgMergeSetting' = array(
  85  *              # Value that will be shared among all wikis:
  86  *              'default' => array( NS_USER => true ),
  87  *
  88  *              # Leading '+' means merging the array of value with the defaults
  89  *              '+beta' => array( NS_HELP => true ),
  90  *      ),
  91  * );
  92  *
  93  * # Get configuration for the German site:
  94  * $conf->get( 'wgMergeSetting', 'de' );
  95  * // --> array( NS_USER => true );
  96  *
  97  * # Get configuration for the testing site:
  98  * $conf->get( 'wgMergeSetting', 'beta' );
  99  * // --> array( NS_USER => true, NS_HELP => true );
 100  * @endcode
 101  *
 102  * Finally, to load all configuration settings, extract them in global context:
 103  *
 104  * @code
 105  * # Name / identifier of the wiki as set in $conf->wikis
 106  * $wikiID = 'beta';
 107  * $globals = $conf->getAll( $wikiID );
 108  * extract( $globals );
 109  * @endcode
 110  *
 111  * @todo Give examples for,
 112  * suffixes:
 113  * $conf->suffixes = array( 'wiki' );
 114  * localVHosts
 115  * callbacks!
 116  */
 117 class SiteConfiguration {
 118
 119         /**
 120          * Array of suffixes, for self::siteFromDB()
 121          */
 122         public $suffixes = array();
 123
 124         /**
 125          * Array of wikis, should be the same as $wgLocalDatabases
 126          */
 127         public $wikis = array();
 128
 129         /**
 130          * The whole array of settings
 131          */
 132         public $settings = array();
 133
 134         /**
 135          * Array of domains that are local and can be handled by the same server
 136          */
 137         public $localVHosts = array();
 138
 139         /**
 140          * Optional callback to load full configuration data.
 141          * @var string|array
 142          */
 143         public $fullLoadCallback = null;
 144
 145         /** Whether or not all data has been loaded */
 146         public $fullLoadDone = false;
 147
 148         /**
 149          * A callback function that returns an array with the following keys (all
 150          * optional):
 151          * - suffix: site's suffix
 152          * - lang: site's lang
 153          * - tags: array of wiki tags
 154          * - params: array of parameters to be replaced
 155          * The function will receive the SiteConfiguration instance in the first
 156          * argument and the wiki in the second one.
 157          * if suffix and lang are passed they will be used for the return value of
 158          * self::siteFromDB() and self::$suffixes will be ignored
 159          *
 160          * @var string|array
 161          */
 162         public $siteParamsCallback = null;
 163
 164         /**
 165          * Configuration cache for getConfig()
 166          * @var array
 167          */
 168         protected $cfgCache = array();
 169
 170         /**
 171          * Retrieves a configuration setting for a given wiki.
 172          * @param string $settingName ID of the setting name to retrieve
 173          * @param string $wiki Wiki ID of the wiki in question.
 174          * @param string $suffix The suffix of the wiki in question.
 175          * @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
 176          * @param array $wikiTags The tags assigned to the wiki.
 177          * @return mixed The value of the setting requested.
 178          */
 179         public function get( $settingName, $wiki, $suffix = null, $params = array(),
 180                 $wikiTags = array()
 181         ) {
 182                 $params = $this->mergeParams( $wiki, $suffix, $params, $wikiTags );
 183                 return $this->getSetting( $settingName, $wiki, $params );
 184         }
 185
 186         /**
 187          * Really retrieves a configuration setting for a given wiki.
 188          *
 189          * @param string $settingName ID of the setting name to retrieve.
 190          * @param string $wiki Wiki ID of the wiki in question.
 191          * @param array $params Array of parameters.
 192          * @return mixed The value of the setting requested.
 193          */
 194         protected function getSetting( $settingName, $wiki, array $params ) {
 195                 $retval = null;
 196                 if ( array_key_exists( $settingName, $this->settings ) ) {
 197                         $thisSetting =& $this->settings[$settingName];
 198                         do {
 199                                 // Do individual wiki settings
 200                                 if ( array_key_exists( $wiki, $thisSetting ) ) {
 201                                         $retval = $thisSetting[$wiki];
 202                                         break;
 203                                 } elseif ( array_key_exists( "+$wiki", $thisSetting ) && is_array( $thisSetting["+$wiki"] ) ) {
 204                                         $retval = $thisSetting["+$wiki"];
 205                                 }
 206
 207                                 // Do tag settings
 208                                 foreach ( $params['tags'] as $tag ) {
 209                                         if ( array_key_exists( $tag, $thisSetting ) ) {
 210                                                 if ( is_array( $retval ) && is_array( $thisSetting[$tag] ) ) {
 211                                                         $retval = self::arrayMerge( $retval, $thisSetting[$tag] );
 212                                                 } else {
 213                                                         $retval = $thisSetting[$tag];
 214                                                 }
 215                                                 break 2;
 216                                         } elseif ( array_key_exists( "+$tag", $thisSetting ) && is_array( $thisSetting["+$tag"] ) ) {
 217                                                 if ( $retval === null ) {
 218                                                         $retval = array();
 219                                                 }
 220                                                 $retval = self::arrayMerge( $retval, $thisSetting["+$tag"] );
 221                                         }
 222                                 }
 223                                 // Do suffix settings
 224                                 $suffix = $params['suffix'];
 225                                 if ( !is_null( $suffix ) ) {
 226                                         if ( array_key_exists( $suffix, $thisSetting ) ) {
 227                                                 if ( is_array( $retval ) && is_array( $thisSetting[$suffix] ) ) {
 228                                                         $retval = self::arrayMerge( $retval, $thisSetting[$suffix] );
 229                                                 } else {
 230                                                         $retval = $thisSetting[$suffix];
 231                                                 }
 232                                                 break;
 233                                         } elseif ( array_key_exists( "+$suffix", $thisSetting )
 234                                                 && is_array( $thisSetting["+$suffix"] )
 235                                         ) {
 236                                                 if ( $retval === null ) {
 237                                                         $retval = array();
 238                                                 }
 239                                                 $retval = self::arrayMerge( $retval, $thisSetting["+$suffix"] );
 240                                         }
 241                                 }
 242
 243                                 // Fall back to default.
 244                                 if ( array_key_exists( 'default', $thisSetting ) ) {
 245                                         if ( is_array( $retval ) && is_array( $thisSetting['default'] ) ) {
 246                                                 $retval = self::arrayMerge( $retval, $thisSetting['default'] );
 247                                         } else {
 248                                                 $retval = $thisSetting['default'];
 249                                         }
 250                                         break;
 251                                 }
 252                         } while ( false );
 253                 }
 254
 255                 if ( !is_null( $retval ) && count( $params['params'] ) ) {
 256                         foreach ( $params['params'] as $key => $value ) {
 257                                 $retval = $this->doReplace( '$' . $key, $value, $retval );
 258                         }
 259                 }
 260                 return $retval;
 261         }
 262
 263         /**
 264          * Type-safe string replace; won't do replacements on non-strings
 265          * private?
 266          *
 267          * @param string $from
 268          * @param string $to
 269          * @param string|array $in
 270          * @return string
 271          */
 272         function doReplace( $from, $to, $in ) {
 273                 if ( is_string( $in ) ) {
 274                         return str_replace( $from, $to, $in );
 275                 } elseif ( is_array( $in ) ) {
 276                         foreach ( $in as $key => $val ) {
 277                                 $in[$key] = $this->doReplace( $from, $to, $val );
 278                         }
 279                         return $in;
 280                 } else {
 281                         return $in;
 282                 }
 283         }
 284
 285         /**
 286          * Gets all settings for a wiki
 287          * @param string $wiki Wiki ID of the wiki in question.
 288          * @param string $suffix The suffix of the wiki in question.
 289          * @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
 290          * @param array $wikiTags The tags assigned to the wiki.
 291          * @return array Array of settings requested.
 292          */
 293         public function getAll( $wiki, $suffix = null, $params = array(), $wikiTags = array() ) {
 294                 $params = $this->mergeParams( $wiki, $suffix, $params, $wikiTags );
 295                 $localSettings = array();
 296                 foreach ( $this->settings as $varname => $stuff ) {
 297                         $append = false;
 298                         $var = $varname;
 299                         if ( substr( $varname, 0, 1 ) == '+' ) {
 300                                 $append = true;
 301                                 $var = substr( $varname, 1 );
 302                         }
 303
 304                         $value = $this->getSetting( $varname, $wiki, $params );
 305                         if ( $append && is_array( $value ) && is_array( $GLOBALS[$var] ) ) {
 306                                 $value = self::arrayMerge( $value, $GLOBALS[$var] );
 307                         }
 308                         if ( !is_null( $value ) ) {
 309                                 $localSettings[$var] = $value;
 310                         }
 311                 }
 312                 return $localSettings;
 313         }
 314
 315         /**
 316          * Retrieves a configuration setting for a given wiki, forced to a boolean.
 317          * @param string $setting ID of the setting name to retrieve
 318          * @param string $wiki Wiki ID of the wiki in question.
 319          * @param string $suffix The suffix of the wiki in question.
 320          * @param array $wikiTags The tags assigned to the wiki.
 321          * @return bool The value of the setting requested.
 322          */
 323         public function getBool( $setting, $wiki, $suffix = null, $wikiTags = array() ) {
 324                 return (bool)$this->get( $setting, $wiki, $suffix, array(), $wikiTags );
 325         }
 326
 327         /**
 328          * Retrieves an array of local databases
 329          *
 330          * @return array
 331          */
 332         function &getLocalDatabases() {
 333                 return $this->wikis;
 334         }
 335
 336         /**
 337          * Retrieves the value of a given setting, and places it in a variable passed by reference.
 338          * @param string $setting ID of the setting name to retrieve
 339          * @param string $wiki Wiki ID of the wiki in question.
 340          * @param string $suffix The suffix of the wiki in question.
 341          * @param array $var Reference The variable to insert the value into.
 342          * @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
 343          * @param array $wikiTags The tags assigned to the wiki.
 344          */
 345         public function extractVar( $setting, $wiki, $suffix, &$var,
 346                 $params = array(), $wikiTags = array()
 347         ) {
 348                 $value = $this->get( $setting, $wiki, $suffix, $params, $wikiTags );
 349                 if ( !is_null( $value ) ) {
 350                         $var = $value;
 351                 }
 352         }
 353
 354         /**
 355          * Retrieves the value of a given setting, and places it in its corresponding global variable.
 356          * @param string $setting ID of the setting name to retrieve
 357          * @param string $wiki Wiki ID of the wiki in question.
 358          * @param string $suffix The suffix of the wiki in question.
 359          * @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
 360          * @param array $wikiTags The tags assigned to the wiki.
 361          */
 362         public function extractGlobal( $setting, $wiki, $suffix = null,
 363                 $params = array(), $wikiTags = array()
 364         ) {
 365                 $params = $this->mergeParams( $wiki, $suffix, $params, $wikiTags );
 366                 $this->extractGlobalSetting( $setting, $wiki, $params );
 367         }
 368
 369         /**
 370          * @param string $setting
 371          * @param string $wiki
 372          * @param array $params
 373          */
 374         public function extractGlobalSetting( $setting, $wiki, $params ) {
 375                 $value = $this->getSetting( $setting, $wiki, $params );
 376                 if ( !is_null( $value ) ) {
 377                         if ( substr( $setting, 0, 1 ) == '+' && is_array( $value ) ) {
 378                                 $setting = substr( $setting, 1 );
 379                                 if ( is_array( $GLOBALS[$setting] ) ) {
 380                                         $GLOBALS[$setting] = self::arrayMerge( $GLOBALS[$setting], $value );
 381                                 } else {
 382                                         $GLOBALS[$setting] = $value;
 383                                 }
 384                         } else {
 385                                 $GLOBALS[$setting] = $value;
 386                         }
 387                 }
 388         }
 389
 390         /**
 391          * Retrieves the values of all settings, and places them in their corresponding global variables.
 392          * @param string $wiki Wiki ID of the wiki in question.
 393          * @param string $suffix The suffix of the wiki in question.
 394          * @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
 395          * @param array $wikiTags The tags assigned to the wiki.
 396          */
 397         public function extractAllGlobals( $wiki, $suffix = null, $params = array(),
 398                 $wikiTags = array()
 399         ) {
 400                 $params = $this->mergeParams( $wiki, $suffix, $params, $wikiTags );
 401                 foreach ( $this->settings as $varName => $setting ) {
 402                         $this->extractGlobalSetting( $varName, $wiki, $params );
 403                 }
 404         }
 405
 406         /**
 407          * Return specific settings for $wiki
 408          * See the documentation of self::$siteParamsCallback for more in-depth
 409          * documentation about this function
 410          *
 411          * @param string $wiki
 412          * @return array
 413          */
 414         protected function getWikiParams( $wiki ) {
 415                 static $default = array(
 416                         'suffix' => null,
 417                         'lang' => null,
 418                         'tags' => array(),
 419                         'params' => array(),
 420                 );
 421
 422                 if ( !is_callable( $this->siteParamsCallback ) ) {
 423                         return $default;
 424                 }
 425
 426                 $ret = call_user_func_array( $this->siteParamsCallback, array( $this, $wiki ) );
 427                 # Validate the returned value
 428                 if ( !is_array( $ret ) ) {
 429                         return $default;
 430                 }
 431
 432                 foreach ( $default as $name => $def ) {
 433                         if ( !isset( $ret[$name] ) || ( is_array( $default[$name] ) && !is_array( $ret[$name] ) ) ) {
 434                                 $ret[$name] = $default[$name];
 435                         }
 436                 }
 437
 438                 return $ret;
 439         }
 440
 441         /**
 442          * Merge params between the ones passed to the function and the ones given
 443          * by self::$siteParamsCallback for backward compatibility
 444          * Values returned by self::getWikiParams() have the priority.
 445          *
 446          * @param string $wiki Wiki ID of the wiki in question.
 447          * @param string $suffix The suffix of the wiki in question.
 448          * @param array $params List of parameters. $.'key' is replaced by $value in
 449          *   all returned data.
 450          * @param array $wikiTags The tags assigned to the wiki.
 451          * @return array
 452          */
 453         protected function mergeParams( $wiki, $suffix, array $params, array $wikiTags ) {
 454                 $ret = $this->getWikiParams( $wiki );
 455
 456                 if ( is_null( $ret['suffix'] ) ) {
 457                         $ret['suffix'] = $suffix;
 458                 }
 459
 460                 $ret['tags'] = array_unique( array_merge( $ret['tags'], $wikiTags ) );
 461
 462                 $ret['params'] += $params;
 463
 464                 // Automatically fill that ones if needed
 465                 if ( !isset( $ret['params']['lang'] ) && !is_null( $ret['lang'] ) ) {
 466                         $ret['params']['lang'] = $ret['lang'];
 467                 }
 468                 if ( !isset( $ret['params']['site'] ) && !is_null( $ret['suffix'] ) ) {
 469                         $ret['params']['site'] = $ret['suffix'];
 470                 }
 471
 472                 return $ret;
 473         }
 474
 475         /**
 476          * Work out the site and language name from a database name
 477          * @param string $db
 478          *
 479          * @return array
 480          */
 481         public function siteFromDB( $db ) {
 482                 // Allow override
 483                 $def = $this->getWikiParams( $db );
 484                 if ( !is_null( $def['suffix'] ) && !is_null( $def['lang'] ) ) {
 485                         return array( $def['suffix'], $def['lang'] );
 486                 }
 487
 488                 $site = null;
 489                 $lang = null;
 490                 foreach ( $this->suffixes as $altSite => $suffix ) {
 491                         if ( $suffix === '' ) {
 492                                 $site = '';
 493                                 $lang = $db;
 494                                 break;
 495                         } elseif ( substr( $db, -strlen( $suffix ) ) == $suffix ) {
 496                                 $site = is_numeric( $altSite ) ? $suffix : $altSite;
 497                                 $lang = substr( $db, 0, strlen( $db ) - strlen( $suffix ) );
 498                                 break;
 499                         }
 500                 }
 501                 $lang = str_replace( '_', '-', $lang );
 502                 return array( $site, $lang );
 503         }
 504
 505         /**
 506          * Get the resolved (post-setup) configuration of a potentially foreign wiki.
 507          * For foreign wikis, this is expensive, and only works if maintenance
 508          * scripts are setup to handle the --wiki parameter such as in wiki farms.
 509          *
 510          * @param string $wiki
 511          * @param array|string $settings A setting name or array of setting names
 512          * @return mixed|mixed[] Array if $settings is an array, otherwise the value
 513          * @throws MWException
 514          * @since 1.21
 515          */
 516         public function getConfig( $wiki, $settings ) {
 517                 global $IP;
 518
 519                 $multi = is_array( $settings );
 520                 $settings = (array)$settings;
 521                 if ( $wiki === wfWikiID() ) { // $wiki is this wiki
 522                         $res = array();
 523                         foreach ( $settings as $name ) {
 524                                 if ( !preg_match( '/^wg[A-Z]/', $name ) ) {
 525                                         throw new MWException( "Variable '$name' does start with 'wg'." );
 526                                 } elseif ( !isset( $GLOBALS[$name] ) ) {
 527                                         throw new MWException( "Variable '$name' is not set." );
 528                                 }
 529                                 $res[$name] = $GLOBALS[$name];
 530                         }
 531                 } else { // $wiki is a foreign wiki
 532                         if ( isset( $this->cfgCache[$wiki] ) ) {
 533                                 $res = array_intersect_key( $this->cfgCache[$wiki], array_flip( $settings ) );
 534                                 if ( count( $res ) == count( $settings ) ) {
 535                                         return $multi ? $res : current( $res ); // cache hit
 536                                 }
 537                         } elseif ( !in_array( $wiki, $this->wikis ) ) {
 538                                 throw new MWException( "No such wiki '$wiki'." );
 539                         } else {
 540                                 $this->cfgCache[$wiki] = array();
 541                         }
 542                         $retVal = 1;
 543                         $cmd = wfShellWikiCmd(
 544                                 "$IP/maintenance/getConfiguration.php",
 545                                 array(
 546                                         '--wiki', $wiki,
 547                                         '--settings', implode( ' ', $settings ),
 548                                         '--format', 'PHP'
 549                                 )
 550                         );
 551                         // ulimit5.sh breaks this call
 552                         $data = trim( wfShellExec( $cmd, $retVal, array(), array( 'memory' => 0 ) ) );
 553                         if ( $retVal != 0 || !strlen( $data ) ) {
 554                                 throw new MWException( "Failed to run getConfiguration.php." );
 555                         }
 556                         $res = unserialize( $data );
 557                         if ( !is_array( $res ) ) {
 558                                 throw new MWException( "Failed to unserialize configuration array." );
 559                         }
 560                         $this->cfgCache[$wiki] = $this->cfgCache[$wiki] + $res;
 561                 }
 562
 563                 return $multi ? $res : current( $res );
 564         }
 565
 566         /**
 567          * Returns true if the given vhost is handled locally.
 568          * @param string $vhost
 569          * @return bool
 570          */
 571         public function isLocalVHost( $vhost ) {
 572                 return in_array( $vhost, $this->localVHosts );
 573         }
 574
 575         /**
 576          * Merge multiple arrays together.
 577          * On encountering duplicate keys, merge the two, but ONLY if they're arrays.
 578          * PHP's array_merge_recursive() merges ANY duplicate values into arrays,
 579          * which is not fun
 580          *
 581          * @param array $array1
 582          *
 583          * @return array
 584          */
 585         static function arrayMerge( $array1/* ... */ ) {
 586                 $out = $array1;
 587                 $argsCount = func_num_args();
 588                 for ( $i = 1; $i < $argsCount; $i++ ) {
 589                         foreach ( func_get_arg( $i ) as $key => $value ) {
 590                                 if ( isset( $out[$key] ) && is_array( $out[$key] ) && is_array( $value ) ) {
 591                                         $out[$key] = self::arrayMerge( $out[$key], $value );
 592                                 } elseif ( !isset( $out[$key] ) || !$out[$key] && !is_numeric( $key ) ) {
 593                                         // Values that evaluate to true given precedence, for the
 594                                         // primary purpose of merging permissions arrays.
 595                                         $out[$key] = $value;
 596                                 } elseif ( is_numeric( $key ) ) {
 597                                         $out[] = $value;
 598                                 }
 599                         }
 600                 }
 601
 602                 return $out;
 603         }
 604
 605         public function loadFullData() {
 606                 if ( $this->fullLoadCallback && !$this->fullLoadDone ) {
 607                         call_user_func( $this->fullLoadCallback, $this );
 608                         $this->fullLoadDone = true;
 609                 }
 610         }
 611 }