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(), $wikiTags = array() ) {
 180                 $params = $this->mergeParams( $wiki, $suffix, $params, $wikiTags );
 181                 return $this->getSetting( $settingName, $wiki, $params );
 182         }
 183
 184         /**
 185          * Really retrieves a configuration setting for a given wiki.
 186          *
 187          * @param string $settingName ID of the setting name to retrieve.
 188          * @param string $wiki Wiki ID of the wiki in question.
 189          * @param array $params array of parameters.
 190          * @return Mixed the value of the setting requested.
 191          */
 192         protected function getSetting( $settingName, $wiki, /*array*/ $params ) {
 193                 $retval = null;
 194                 if ( array_key_exists( $settingName, $this->settings ) ) {
 195                         $thisSetting =& $this->settings[$settingName];
 196                         do {
 197                                 // Do individual wiki settings
 198                                 if ( array_key_exists( $wiki, $thisSetting ) ) {
 199                                         $retval = $thisSetting[$wiki];
 200                                         break;
 201                                 } elseif ( array_key_exists( "+$wiki", $thisSetting ) && is_array( $thisSetting["+$wiki"] ) ) {
 202                                         $retval = $thisSetting["+$wiki"];
 203                                 }
 204
 205                                 // Do tag settings
 206                                 foreach ( $params['tags'] as $tag ) {
 207                                         if ( array_key_exists( $tag, $thisSetting ) ) {
 208                                                 if ( isset( $retval ) && is_array( $retval ) && is_array( $thisSetting[$tag] ) ) {
 209                                                         $retval = self::arrayMerge( $retval, $thisSetting[$tag] );
 210                                                 } else {
 211                                                         $retval = $thisSetting[$tag];
 212                                                 }
 213                                                 break 2;
 214                                         } elseif ( array_key_exists( "+$tag", $thisSetting ) && is_array( $thisSetting["+$tag"] ) ) {
 215                                                 if ( !isset( $retval ) ) {
 216                                                         $retval = array();
 217                                                 }
 218                                                 $retval = self::arrayMerge( $retval, $thisSetting["+$tag"] );
 219                                         }
 220                                 }
 221                                 // Do suffix settings
 222                                 $suffix = $params['suffix'];
 223                                 if ( !is_null( $suffix ) ) {
 224                                         if ( array_key_exists( $suffix, $thisSetting ) ) {
 225                                                 if ( isset( $retval ) && is_array( $retval ) && is_array( $thisSetting[$suffix] ) ) {
 226                                                         $retval = self::arrayMerge( $retval, $thisSetting[$suffix] );
 227                                                 } else {
 228                                                         $retval = $thisSetting[$suffix];
 229                                                 }
 230                                                 break;
 231                                         } elseif ( array_key_exists( "+$suffix", $thisSetting ) && is_array( $thisSetting["+$suffix"] ) ) {
 232                                                 if ( !isset( $retval ) ) {
 233                                                         $retval = array();
 234                                                 }
 235                                                 $retval = self::arrayMerge( $retval, $thisSetting["+$suffix"] );
 236                                         }
 237                                 }
 238
 239                                 // Fall back to default.
 240                                 if ( array_key_exists( 'default', $thisSetting ) ) {
 241                                         if ( is_array( $retval ) && is_array( $thisSetting['default'] ) ) {
 242                                                 $retval = self::arrayMerge( $retval, $thisSetting['default'] );
 243                                         } else {
 244                                                 $retval = $thisSetting['default'];
 245                                         }
 246                                         break;
 247                                 }
 248                         } while ( false );
 249                 }
 250
 251                 if ( !is_null( $retval ) && count( $params['params'] ) ) {
 252                         foreach ( $params['params'] as $key => $value ) {
 253                                 $retval = $this->doReplace( '$' . $key, $value, $retval );
 254                         }
 255                 }
 256                 return $retval;
 257         }
 258
 259         /**
 260          * Type-safe string replace; won't do replacements on non-strings
 261          * private?
 262          *
 263          * @param $from
 264          * @param $to
 265          * @param $in
 266          * @return string
 267          */
 268         function doReplace( $from, $to, $in ) {
 269                 if ( is_string( $in ) ) {
 270                         return str_replace( $from, $to, $in );
 271                 } elseif ( is_array( $in ) ) {
 272                         foreach ( $in as $key => $val ) {
 273                                 $in[$key] = $this->doReplace( $from, $to, $val );
 274                         }
 275                         return $in;
 276                 } else {
 277                         return $in;
 278                 }
 279         }
 280
 281         /**
 282          * Gets all settings for a wiki
 283          * @param string $wiki Wiki ID of the wiki in question.
 284          * @param string $suffix The suffix of the wiki in question.
 285          * @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
 286          * @param array $wikiTags The tags assigned to the wiki.
 287          * @return Array Array of settings requested.
 288          */
 289         public function getAll( $wiki, $suffix = null, $params = array(), $wikiTags = array() ) {
 290                 $params = $this->mergeParams( $wiki, $suffix, $params, $wikiTags );
 291                 $localSettings = array();
 292                 foreach ( $this->settings as $varname => $stuff ) {
 293                         $append = false;
 294                         $var = $varname;
 295                         if ( substr( $varname, 0, 1 ) == '+' ) {
 296                                 $append = true;
 297                                 $var = substr( $varname, 1 );
 298                         }
 299
 300                         $value = $this->getSetting( $varname, $wiki, $params );
 301                         if ( $append && is_array( $value ) && is_array( $GLOBALS[$var] ) ) {
 302                                 $value = self::arrayMerge( $value, $GLOBALS[$var] );
 303                         }
 304                         if ( !is_null( $value ) ) {
 305                                 $localSettings[$var] = $value;
 306                         }
 307                 }
 308                 return $localSettings;
 309         }
 310
 311         /**
 312          * Retrieves a configuration setting for a given wiki, forced to a boolean.
 313          * @param string $setting ID of the setting name to retrieve
 314          * @param string $wiki Wiki ID of the wiki in question.
 315          * @param string $suffix The suffix of the wiki in question.
 316          * @param array $wikiTags The tags assigned to the wiki.
 317          * @return bool The value of the setting requested.
 318          */
 319         public function getBool( $setting, $wiki, $suffix = null, $wikiTags = array() ) {
 320                 return (bool)$this->get( $setting, $wiki, $suffix, array(), $wikiTags );
 321         }
 322
 323         /**
 324          * Retrieves an array of local databases
 325          *
 326          * @return array
 327          */
 328         function &getLocalDatabases() {
 329                 return $this->wikis;
 330         }
 331
 332         /**
 333          * Retrieves the value of a given setting, and places it in a variable passed by reference.
 334          * @param string $setting ID of the setting name to retrieve
 335          * @param string $wiki Wiki ID of the wiki in question.
 336          * @param string $suffix The suffix of the wiki in question.
 337          * @param array $var Reference The variable to insert the value into.
 338          * @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
 339          * @param array $wikiTags The tags assigned to the wiki.
 340          */
 341         public function extractVar( $setting, $wiki, $suffix, &$var, $params = array(), $wikiTags = array() ) {
 342                 $value = $this->get( $setting, $wiki, $suffix, $params, $wikiTags );
 343                 if ( !is_null( $value ) ) {
 344                         $var = $value;
 345                 }
 346         }
 347
 348         /**
 349          * Retrieves the value of a given setting, and places it in its corresponding global variable.
 350          * @param string $setting ID of the setting name to retrieve
 351          * @param string $wiki Wiki ID of the wiki in question.
 352          * @param string $suffix The suffix of the wiki in question.
 353          * @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
 354          * @param array $wikiTags The tags assigned to the wiki.
 355          */
 356         public function extractGlobal( $setting, $wiki, $suffix = null, $params = array(), $wikiTags = array() ) {
 357                 $params = $this->mergeParams( $wiki, $suffix, $params, $wikiTags );
 358                 $this->extractGlobalSetting( $setting, $wiki, $params );
 359         }
 360
 361         /**
 362          * @param $setting string
 363          * @param $wiki string
 364          * @param $params array
 365          */
 366         public function extractGlobalSetting( $setting, $wiki, $params ) {
 367                 $value = $this->getSetting( $setting, $wiki, $params );
 368                 if ( !is_null( $value ) ) {
 369                         if ( substr( $setting, 0, 1 ) == '+' && is_array( $value ) ) {
 370                                 $setting = substr( $setting, 1 );
 371                                 if ( is_array( $GLOBALS[$setting] ) ) {
 372                                         $GLOBALS[$setting] = self::arrayMerge( $GLOBALS[$setting], $value );
 373                                 } else {
 374                                         $GLOBALS[$setting] = $value;
 375                                 }
 376                         } else {
 377                                 $GLOBALS[$setting] = $value;
 378                         }
 379                 }
 380         }
 381
 382         /**
 383          * Retrieves the values of all settings, and places them in their corresponding global variables.
 384          * @param string $wiki Wiki ID of the wiki in question.
 385          * @param string $suffix The suffix of the wiki in question.
 386          * @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
 387          * @param array $wikiTags The tags assigned to the wiki.
 388          */
 389         public function extractAllGlobals( $wiki, $suffix = null, $params = array(), $wikiTags = array() ) {
 390                 $params = $this->mergeParams( $wiki, $suffix, $params, $wikiTags );
 391                 foreach ( $this->settings as $varName => $setting ) {
 392                         $this->extractGlobalSetting( $varName, $wiki, $params );
 393                 }
 394         }
 395
 396         /**
 397          * Return specific settings for $wiki
 398          * See the documentation of self::$siteParamsCallback for more in-depth
 399          * documentation about this function
 400          *
 401          * @param $wiki String
 402          * @return array
 403          */
 404         protected function getWikiParams( $wiki ) {
 405                 static $default = array(
 406                         'suffix' => null,
 407                         'lang' => null,
 408                         'tags' => array(),
 409                         'params' => array(),
 410                 );
 411
 412                 if ( !is_callable( $this->siteParamsCallback ) ) {
 413                         return $default;
 414                 }
 415
 416                 $ret = call_user_func_array( $this->siteParamsCallback, array( $this, $wiki ) );
 417                 # Validate the returned value
 418                 if ( !is_array( $ret ) ) {
 419                         return $default;
 420                 }
 421
 422                 foreach ( $default as $name => $def ) {
 423                         if ( !isset( $ret[$name] ) || ( is_array( $default[$name] ) && !is_array( $ret[$name] ) ) ) {
 424                                 $ret[$name] = $default[$name];
 425                         }
 426                 }
 427
 428                 return $ret;
 429         }
 430
 431         /**
 432          * Merge params between the ones passed to the function and the ones given
 433          * by self::$siteParamsCallback for backward compatibility
 434          * Values returned by self::getWikiParams() have the priority.
 435          *
 436          * @param string $wiki Wiki ID of the wiki in question.
 437          * @param string $suffix The suffix of the wiki in question.
 438          * @param array $params List of parameters. $.'key' is replaced by $value in
 439          *                all returned data.
 440          * @param array $wikiTags The tags assigned to the wiki.
 441          * @return array
 442          */
 443         protected function mergeParams( $wiki, $suffix, /*array*/ $params, /*array*/ $wikiTags ) {
 444                 $ret = $this->getWikiParams( $wiki );
 445
 446                 if ( is_null( $ret['suffix'] ) ) {
 447                         $ret['suffix'] = $suffix;
 448                 }
 449
 450                 $ret['tags'] = array_unique( array_merge( $ret['tags'], $wikiTags ) );
 451
 452                 $ret['params'] += $params;
 453
 454                 // Automatically fill that ones if needed
 455                 if ( !isset( $ret['params']['lang'] ) && !is_null( $ret['lang'] ) ) {
 456                         $ret['params']['lang'] = $ret['lang'];
 457                 }
 458                 if ( !isset( $ret['params']['site'] ) && !is_null( $ret['suffix'] ) ) {
 459                         $ret['params']['site'] = $ret['suffix'];
 460                 }
 461
 462                 return $ret;
 463         }
 464
 465         /**
 466          * Work out the site and language name from a database name
 467          * @param $db
 468          *
 469          * @return array
 470          */
 471         public function siteFromDB( $db ) {
 472                 // Allow override
 473                 $def = $this->getWikiParams( $db );
 474                 if ( !is_null( $def['suffix'] ) && !is_null( $def['lang'] ) ) {
 475                         return array( $def['suffix'], $def['lang'] );
 476                 }
 477
 478                 $site = null;
 479                 $lang = null;
 480                 foreach ( $this->suffixes as $suffix ) {
 481                         if ( $suffix === '' ) {
 482                                 $site = '';
 483                                 $lang = $db;
 484                                 break;
 485                         } elseif ( substr( $db, -strlen( $suffix ) ) == $suffix ) {
 486                                 $site = $suffix == 'wiki' ? 'wikipedia' : $suffix;
 487                                 $lang = substr( $db, 0, strlen( $db ) - strlen( $suffix ) );
 488                                 break;
 489                         }
 490                 }
 491                 $lang = str_replace( '_', '-', $lang );
 492                 return array( $site, $lang );
 493         }
 494
 495         /**
 496          * Get the resolved (post-setup) configuration of a potentially foreign wiki.
 497          * For foreign wikis, this is expensive, and only works if maintenance
 498          * scripts are setup to handle the --wiki parameter such as in wiki farms.
 499          *
 500          * @param string $wiki
 501          * @param array|string $settings A setting name or array of setting names
 502          * @return Array|mixed Array if $settings is an array, otherwise the value
 503          * @throws MWException
 504          * @since 1.21
 505          */
 506         public function getConfig( $wiki, $settings ) {
 507                 global $IP;
 508
 509                 $multi = is_array( $settings );
 510                 $settings = (array)$settings;
 511                 if ( $wiki === wfWikiID() ) { // $wiki is this wiki
 512                         $res = array();
 513                         foreach ( $settings as $name ) {
 514                                 if ( !preg_match( '/^wg[A-Z]/', $name ) ) {
 515                                         throw new MWException( "Variable '$name' does start with 'wg'." );
 516                                 } elseif ( !isset( $GLOBALS[$name] ) ) {
 517                                         throw new MWException( "Variable '$name' is not set." );
 518                                 }
 519                                 $res[$name] = $GLOBALS[$name];
 520                         }
 521                 } else { // $wiki is a foreign wiki
 522                         if ( isset( $this->cfgCache[$wiki] ) ) {
 523                                 $res = array_intersect_key( $this->cfgCache[$wiki], array_flip( $settings ) );
 524                                 if ( count( $res ) == count( $settings ) ) {
 525                                         return $res; // cache hit
 526                                 }
 527                         } elseif ( !in_array( $wiki, $this->wikis ) ) {
 528                                 throw new MWException( "No such wiki '$wiki'." );
 529                         } else {
 530                                 $this->cfgCache[$wiki] = array();
 531                         }
 532                         $retVal = 1;
 533                         $cmd = wfShellWikiCmd(
 534                                 "$IP/maintenance/getConfiguration.php",
 535                                 array(
 536                                         '--wiki', $wiki,
 537                                         '--settings', implode( ' ', $settings ),
 538                                         '--format', 'PHP'
 539                                 )
 540                         );
 541                         // ulimit5.sh breaks this call
 542                         $data = trim( wfShellExec( $cmd, $retVal, array(), array( 'memory' => 0 ) ) );
 543                         if ( $retVal != 0 || !strlen( $data ) ) {
 544                                 throw new MWException( "Failed to run getConfiguration.php." );
 545                         }
 546                         $res = unserialize( $data );
 547                         if ( !is_array( $res ) ) {
 548                                 throw new MWException( "Failed to unserialize configuration array." );
 549                         }
 550                         $this->cfgCache[$wiki] = $this->cfgCache[$wiki] + $res;
 551                 }
 552
 553                 return $multi ? $res : current( $res );
 554         }
 555
 556         /**
 557          * Returns true if the given vhost is handled locally.
 558          * @param $vhost String
 559          * @return bool
 560          */
 561         public function isLocalVHost( $vhost ) {
 562                 return in_array( $vhost, $this->localVHosts );
 563         }
 564
 565         /**
 566          * Merge multiple arrays together.
 567          * On encountering duplicate keys, merge the two, but ONLY if they're arrays.
 568          * PHP's array_merge_recursive() merges ANY duplicate values into arrays,
 569          * which is not fun
 570          *
 571          * @param $array1 array
 572          *
 573          * @return array
 574          */
 575         static function arrayMerge( $array1/* ... */ ) {
 576                 $out = $array1;
 577                 for ( $i = 1; $i < func_num_args(); $i++ ) {
 578                         foreach ( func_get_arg( $i ) as $key => $value ) {
 579                                 if ( isset( $out[$key] ) && is_array( $out[$key] ) && is_array( $value ) ) {
 580                                         $out[$key] = self::arrayMerge( $out[$key], $value );
 581                                 } elseif ( !isset( $out[$key] ) || !$out[$key] && !is_numeric( $key ) ) {
 582                                         // Values that evaluate to true given precedence, for the primary purpose of merging permissions arrays.
 583                                         $out[$key] = $value;
 584                                 } elseif ( is_numeric( $key ) ) {
 585                                         $out[] = $value;
 586                                 }
 587                         }
 588                 }
 589
 590                 return $out;
 591         }
 592
 593         public function loadFullData() {
 594                 if ( $this->fullLoadCallback && !$this->fullLoadDone ) {
 595                         call_user_func( $this->fullLoadCallback, $this );
 596                         $this->fullLoadDone = true;
 597                 }
 598         }
 599 }