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 = [ '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 = [
  47  *      'wgSomeSetting' => [
  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 = [
  66  *      'wgSomeSetting' => [
  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 = [
  84  *      'wgMergeSetting' = [
  85  *              # Value that will be shared among all wikis:
  86  *              'default' => [ NS_USER => true ],
  87  *
  88  *              # Leading '+' means merging the array of value with the defaults
  89  *              '+beta' => [ NS_HELP => true ],
  90  *      ],
  91  * ];
  92  *
  93  * # Get configuration for the German site:
  94  * $conf->get( 'wgMergeSetting', 'de' );
  95  * // --> [ NS_USER => true ];
  96  *
  97  * # Get configuration for the testing site:
  98  * $conf->get( 'wgMergeSetting', 'beta' );
  99  * // --> [ 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  * @note For WikiMap to function, the configuration must define string values for
 112  *  $wgServer (or $wgCanonicalServer) and $wgArticlePath, even if these are the
 113  *  same for all wikis or can be correctly determined by the logic in
 114  *  Setup.php.
 115  *
 116  * @todo Give examples for,
 117  * suffixes:
 118  * $conf->suffixes = [ 'wiki' ];
 119  * localVHosts
 120  * callbacks!
 121  */
 122 class SiteConfiguration {
 123
 124         /**
 125          * Array of suffixes, for self::siteFromDB()
 126          */
 127         public $suffixes = [];
 128
 129         /**
 130          * Array of wikis, should be the same as $wgLocalDatabases
 131          */
 132         public $wikis = [];
 133
 134         /**
 135          * The whole array of settings
 136          */
 137         public $settings = [];
 138
 139         /**
 140          * Array of domains that are local and can be handled by the same server
 141          *
 142          * @deprecated since 1.25; use $wgLocalVirtualHosts instead.
 143          */
 144         public $localVHosts = [];
 145
 146         /**
 147          * Optional callback to load full configuration data.
 148          * @var string|array
 149          */
 150         public $fullLoadCallback = null;
 151
 152         /** Whether or not all data has been loaded */
 153         public $fullLoadDone = false;
 154
 155         /**
 156          * A callback function that returns an array with the following keys (all
 157          * optional):
 158          * - suffix: site's suffix
 159          * - lang: site's lang
 160          * - tags: array of wiki tags
 161          * - params: array of parameters to be replaced
 162          * The function will receive the SiteConfiguration instance in the first
 163          * argument and the wiki in the second one.
 164          * if suffix and lang are passed they will be used for the return value of
 165          * self::siteFromDB() and self::$suffixes will be ignored
 166          *
 167          * @var string|array
 168          */
 169         public $siteParamsCallback = null;
 170
 171         /**
 172          * Configuration cache for getConfig()
 173          * @var array
 174          */
 175         protected $cfgCache = [];
 176
 177         /**
 178          * Retrieves a configuration setting for a given wiki.
 179          * @param string $settingName ID of the setting name to retrieve
 180          * @param string $wiki Wiki ID of the wiki in question.
 181          * @param string $suffix The suffix of the wiki in question.
 182          * @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
 183          * @param array $wikiTags The tags assigned to the wiki.
 184          * @return mixed The value of the setting requested.
 185          */
 186         public function get( $settingName, $wiki, $suffix = null, $params = [],
 187                 $wikiTags = []
 188         ) {
 189                 $params = $this->mergeParams( $wiki, $suffix, $params, $wikiTags );
 190                 return $this->getSetting( $settingName, $wiki, $params );
 191         }
 192
 193         /**
 194          * Really retrieves a configuration setting for a given wiki.
 195          *
 196          * @param string $settingName ID of the setting name to retrieve.
 197          * @param string $wiki Wiki ID of the wiki in question.
 198          * @param array $params Array of parameters.
 199          * @return mixed The value of the setting requested.
 200          */
 201         protected function getSetting( $settingName, $wiki, array $params ) {
 202                 $retval = null;
 203                 if ( array_key_exists( $settingName, $this->settings ) ) {
 204                         $thisSetting =& $this->settings[$settingName];
 205                         do {
 206                                 // Do individual wiki settings
 207                                 if ( array_key_exists( $wiki, $thisSetting ) ) {
 208                                         $retval = $thisSetting[$wiki];
 209                                         break;
 210                                 } elseif ( array_key_exists( "+$wiki", $thisSetting ) && is_array( $thisSetting["+$wiki"] ) ) {
 211                                         $retval = $thisSetting["+$wiki"];
 212                                 }
 213
 214                                 // Do tag settings
 215                                 foreach ( $params['tags'] as $tag ) {
 216                                         if ( array_key_exists( $tag, $thisSetting ) ) {
 217                                                 if ( is_array( $retval ) && is_array( $thisSetting[$tag] ) ) {
 218                                                         $retval = self::arrayMerge( $retval, $thisSetting[$tag] );
 219                                                 } else {
 220                                                         $retval = $thisSetting[$tag];
 221                                                 }
 222                                                 break 2;
 223                                         } elseif ( array_key_exists( "+$tag", $thisSetting ) && is_array( $thisSetting["+$tag"] ) ) {
 224                                                 if ( $retval === null ) {
 225                                                         $retval = [];
 226                                                 }
 227                                                 $retval = self::arrayMerge( $retval, $thisSetting["+$tag"] );
 228                                         }
 229                                 }
 230                                 // Do suffix settings
 231                                 $suffix = $params['suffix'];
 232                                 if ( !is_null( $suffix ) ) {
 233                                         if ( array_key_exists( $suffix, $thisSetting ) ) {
 234                                                 if ( is_array( $retval ) && is_array( $thisSetting[$suffix] ) ) {
 235                                                         $retval = self::arrayMerge( $retval, $thisSetting[$suffix] );
 236                                                 } else {
 237                                                         $retval = $thisSetting[$suffix];
 238                                                 }
 239                                                 break;
 240                                         } elseif ( array_key_exists( "+$suffix", $thisSetting )
 241                                                 && is_array( $thisSetting["+$suffix"] )
 242                                         ) {
 243                                                 if ( $retval === null ) {
 244                                                         $retval = [];
 245                                                 }
 246                                                 $retval = self::arrayMerge( $retval, $thisSetting["+$suffix"] );
 247                                         }
 248                                 }
 249
 250                                 // Fall back to default.
 251                                 if ( array_key_exists( 'default', $thisSetting ) ) {
 252                                         if ( is_array( $retval ) && is_array( $thisSetting['default'] ) ) {
 253                                                 $retval = self::arrayMerge( $retval, $thisSetting['default'] );
 254                                         } else {
 255                                                 $retval = $thisSetting['default'];
 256                                         }
 257                                         break;
 258                                 }
 259                         } while ( false );
 260                 }
 261
 262                 if ( !is_null( $retval ) && count( $params['params'] ) ) {
 263                         foreach ( $params['params'] as $key => $value ) {
 264                                 $retval = $this->doReplace( '$' . $key, $value, $retval );
 265                         }
 266                 }
 267                 return $retval;
 268         }
 269
 270         /**
 271          * Type-safe string replace; won't do replacements on non-strings
 272          * private?
 273          *
 274          * @param string $from
 275          * @param string $to
 276          * @param string|array $in
 277          * @return string|array
 278          */
 279         function doReplace( $from, $to, $in ) {
 280                 if ( is_string( $in ) ) {
 281                         return str_replace( $from, $to, $in );
 282                 } elseif ( is_array( $in ) ) {
 283                         foreach ( $in as $key => $val ) {
 284                                 $in[$key] = $this->doReplace( $from, $to, $val );
 285                         }
 286                         return $in;
 287                 } else {
 288                         return $in;
 289                 }
 290         }
 291
 292         /**
 293          * Gets all settings for a wiki
 294          * @param string $wiki Wiki ID of the wiki in question.
 295          * @param string $suffix The suffix of the wiki in question.
 296          * @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
 297          * @param array $wikiTags The tags assigned to the wiki.
 298          * @return array Array of settings requested.
 299          */
 300         public function getAll( $wiki, $suffix = null, $params = [], $wikiTags = [] ) {
 301                 $params = $this->mergeParams( $wiki, $suffix, $params, $wikiTags );
 302                 $localSettings = [];
 303                 foreach ( $this->settings as $varname => $stuff ) {
 304                         $append = false;
 305                         $var = $varname;
 306                         if ( substr( $varname, 0, 1 ) == '+' ) {
 307                                 $append = true;
 308                                 $var = substr( $varname, 1 );
 309                         }
 310
 311                         $value = $this->getSetting( $varname, $wiki, $params );
 312                         if ( $append && is_array( $value ) && is_array( $GLOBALS[$var] ) ) {
 313                                 $value = self::arrayMerge( $value, $GLOBALS[$var] );
 314                         }
 315                         if ( !is_null( $value ) ) {
 316                                 $localSettings[$var] = $value;
 317                         }
 318                 }
 319                 return $localSettings;
 320         }
 321
 322         /**
 323          * Retrieves a configuration setting for a given wiki, forced to a boolean.
 324          * @param string $setting ID of the setting name to retrieve
 325          * @param string $wiki Wiki ID of the wiki in question.
 326          * @param string $suffix The suffix of the wiki in question.
 327          * @param array $wikiTags The tags assigned to the wiki.
 328          * @return bool The value of the setting requested.
 329          */
 330         public function getBool( $setting, $wiki, $suffix = null, $wikiTags = [] ) {
 331                 return (bool)$this->get( $setting, $wiki, $suffix, [], $wikiTags );
 332         }
 333
 334         /**
 335          * Retrieves an array of local databases
 336          *
 337          * @return array
 338          */
 339         function &getLocalDatabases() {
 340                 return $this->wikis;
 341         }
 342
 343         /**
 344          * Retrieves the value of a given setting, and places it in a variable passed by reference.
 345          * @param string $setting ID of the setting name to retrieve
 346          * @param string $wiki Wiki ID of the wiki in question.
 347          * @param string $suffix The suffix of the wiki in question.
 348          * @param array $var Reference The variable to insert the value into.
 349          * @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
 350          * @param array $wikiTags The tags assigned to the wiki.
 351          */
 352         public function extractVar( $setting, $wiki, $suffix, &$var,
 353                 $params = [], $wikiTags = []
 354         ) {
 355                 $value = $this->get( $setting, $wiki, $suffix, $params, $wikiTags );
 356                 if ( !is_null( $value ) ) {
 357                         $var = $value;
 358                 }
 359         }
 360
 361         /**
 362          * Retrieves the value of a given setting, and places it in its corresponding global variable.
 363          * @param string $setting ID of the setting name to retrieve
 364          * @param string $wiki Wiki ID of the wiki in question.
 365          * @param string $suffix The suffix of the wiki in question.
 366          * @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
 367          * @param array $wikiTags The tags assigned to the wiki.
 368          */
 369         public function extractGlobal( $setting, $wiki, $suffix = null,
 370                 $params = [], $wikiTags = []
 371         ) {
 372                 $params = $this->mergeParams( $wiki, $suffix, $params, $wikiTags );
 373                 $this->extractGlobalSetting( $setting, $wiki, $params );
 374         }
 375
 376         /**
 377          * @param string $setting
 378          * @param string $wiki
 379          * @param array $params
 380          */
 381         public function extractGlobalSetting( $setting, $wiki, $params ) {
 382                 $value = $this->getSetting( $setting, $wiki, $params );
 383                 if ( !is_null( $value ) ) {
 384                         if ( substr( $setting, 0, 1 ) == '+' && is_array( $value ) ) {
 385                                 $setting = substr( $setting, 1 );
 386                                 if ( is_array( $GLOBALS[$setting] ) ) {
 387                                         $GLOBALS[$setting] = self::arrayMerge( $GLOBALS[$setting], $value );
 388                                 } else {
 389                                         $GLOBALS[$setting] = $value;
 390                                 }
 391                         } else {
 392                                 $GLOBALS[$setting] = $value;
 393                         }
 394                 }
 395         }
 396
 397         /**
 398          * Retrieves the values of all settings, and places them in their corresponding global variables.
 399          * @param string $wiki Wiki ID of the wiki in question.
 400          * @param string $suffix The suffix of the wiki in question.
 401          * @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
 402          * @param array $wikiTags The tags assigned to the wiki.
 403          */
 404         public function extractAllGlobals( $wiki, $suffix = null, $params = [],
 405                 $wikiTags = []
 406         ) {
 407                 $params = $this->mergeParams( $wiki, $suffix, $params, $wikiTags );
 408                 foreach ( $this->settings as $varName => $setting ) {
 409                         $this->extractGlobalSetting( $varName, $wiki, $params );
 410                 }
 411         }
 412
 413         /**
 414          * Return specific settings for $wiki
 415          * See the documentation of self::$siteParamsCallback for more in-depth
 416          * documentation about this function
 417          *
 418          * @param string $wiki
 419          * @return array
 420          */
 421         protected function getWikiParams( $wiki ) {
 422                 static $default = [
 423                         'suffix' => null,
 424                         'lang' => null,
 425                         'tags' => [],
 426                         'params' => [],
 427                 ];
 428
 429                 if ( !is_callable( $this->siteParamsCallback ) ) {
 430                         return $default;
 431                 }
 432
 433                 $ret = call_user_func_array( $this->siteParamsCallback, [ $this, $wiki ] );
 434                 # Validate the returned value
 435                 if ( !is_array( $ret ) ) {
 436                         return $default;
 437                 }
 438
 439                 foreach ( $default as $name => $def ) {
 440                         if ( !isset( $ret[$name] ) || ( is_array( $default[$name] ) && !is_array( $ret[$name] ) ) ) {
 441                                 $ret[$name] = $default[$name];
 442                         }
 443                 }
 444
 445                 return $ret;
 446         }
 447
 448         /**
 449          * Merge params between the ones passed to the function and the ones given
 450          * by self::$siteParamsCallback for backward compatibility
 451          * Values returned by self::getWikiParams() have the priority.
 452          *
 453          * @param string $wiki Wiki ID of the wiki in question.
 454          * @param string $suffix The suffix of the wiki in question.
 455          * @param array $params List of parameters. $.'key' is replaced by $value in
 456          *   all returned data.
 457          * @param array $wikiTags The tags assigned to the wiki.
 458          * @return array
 459          */
 460         protected function mergeParams( $wiki, $suffix, array $params, array $wikiTags ) {
 461                 $ret = $this->getWikiParams( $wiki );
 462
 463                 if ( is_null( $ret['suffix'] ) ) {
 464                         $ret['suffix'] = $suffix;
 465                 }
 466
 467                 $ret['tags'] = array_unique( array_merge( $ret['tags'], $wikiTags ) );
 468
 469                 $ret['params'] += $params;
 470
 471                 // Automatically fill that ones if needed
 472                 if ( !isset( $ret['params']['lang'] ) && !is_null( $ret['lang'] ) ) {
 473                         $ret['params']['lang'] = $ret['lang'];
 474                 }
 475                 if ( !isset( $ret['params']['site'] ) && !is_null( $ret['suffix'] ) ) {
 476                         $ret['params']['site'] = $ret['suffix'];
 477                 }
 478
 479                 return $ret;
 480         }
 481
 482         /**
 483          * Work out the site and language name from a database name
 484          * @param string $db
 485          *
 486          * @return array
 487          */
 488         public function siteFromDB( $db ) {
 489                 // Allow override
 490                 $def = $this->getWikiParams( $db );
 491                 if ( !is_null( $def['suffix'] ) && !is_null( $def['lang'] ) ) {
 492                         return [ $def['suffix'], $def['lang'] ];
 493                 }
 494
 495                 $site = null;
 496                 $lang = null;
 497                 foreach ( $this->suffixes as $altSite => $suffix ) {
 498                         if ( $suffix === '' ) {
 499                                 $site = '';
 500                                 $lang = $db;
 501                                 break;
 502                         } elseif ( substr( $db, -strlen( $suffix ) ) == $suffix ) {
 503                                 $site = is_numeric( $altSite ) ? $suffix : $altSite;
 504                                 $lang = substr( $db, 0, strlen( $db ) - strlen( $suffix ) );
 505                                 break;
 506                         }
 507                 }
 508                 $lang = str_replace( '_', '-', $lang );
 509                 return [ $site, $lang ];
 510         }
 511
 512         /**
 513          * Get the resolved (post-setup) configuration of a potentially foreign wiki.
 514          * For foreign wikis, this is expensive, and only works if maintenance
 515          * scripts are setup to handle the --wiki parameter such as in wiki farms.
 516          *
 517          * @param string $wiki
 518          * @param array|string $settings A setting name or array of setting names
 519          * @return mixed|mixed[] Array if $settings is an array, otherwise the value
 520          * @throws MWException
 521          * @since 1.21
 522          */
 523         public function getConfig( $wiki, $settings ) {
 524                 global $IP;
 525
 526                 $multi = is_array( $settings );
 527                 $settings = (array)$settings;
 528                 if ( $wiki === wfWikiID() ) { // $wiki is this wiki
 529                         $res = [];
 530                         foreach ( $settings as $name ) {
 531                                 if ( !preg_match( '/^wg[A-Z]/', $name ) ) {
 532                                         throw new MWException( "Variable '$name' does start with 'wg'." );
 533                                 } elseif ( !isset( $GLOBALS[$name] ) ) {
 534                                         throw new MWException( "Variable '$name' is not set." );
 535                                 }
 536                                 $res[$name] = $GLOBALS[$name];
 537                         }
 538                 } else { // $wiki is a foreign wiki
 539                         if ( isset( $this->cfgCache[$wiki] ) ) {
 540                                 $res = array_intersect_key( $this->cfgCache[$wiki], array_flip( $settings ) );
 541                                 if ( count( $res ) == count( $settings ) ) {
 542                                         return $multi ? $res : current( $res ); // cache hit
 543                                 }
 544                         } elseif ( !in_array( $wiki, $this->wikis ) ) {
 545                                 throw new MWException( "No such wiki '$wiki'." );
 546                         } else {
 547                                 $this->cfgCache[$wiki] = [];
 548                         }
 549                         $retVal = 1;
 550                         $cmd = wfShellWikiCmd(
 551                                 "$IP/maintenance/getConfiguration.php",
 552                                 [
 553                                         '--wiki', $wiki,
 554                                         '--settings', implode( ' ', $settings ),
 555                                         '--format', 'PHP'
 556                                 ]
 557                         );
 558                         // ulimit5.sh breaks this call
 559                         $data = trim( wfShellExec( $cmd, $retVal, [], [ 'memory' => 0 ] ) );
 560                         if ( $retVal != 0 || !strlen( $data ) ) {
 561                                 throw new MWException( "Failed to run getConfiguration.php." );
 562                         }
 563                         $res = unserialize( $data );
 564                         if ( !is_array( $res ) ) {
 565                                 throw new MWException( "Failed to unserialize configuration array." );
 566                         }
 567                         $this->cfgCache[$wiki] = $this->cfgCache[$wiki] + $res;
 568                 }
 569
 570                 return $multi ? $res : current( $res );
 571         }
 572
 573         /**
 574          * Merge multiple arrays together.
 575          * On encountering duplicate keys, merge the two, but ONLY if they're arrays.
 576          * PHP's array_merge_recursive() merges ANY duplicate values into arrays,
 577          * which is not fun
 578          *
 579          * @param array $array1
 580          *
 581          * @return array
 582          */
 583         static function arrayMerge( $array1/* ... */ ) {
 584                 $out = $array1;
 585                 $argsCount = func_num_args();
 586                 for ( $i = 1; $i < $argsCount; $i++ ) {
 587                         foreach ( func_get_arg( $i ) as $key => $value ) {
 588                                 if ( isset( $out[$key] ) && is_array( $out[$key] ) && is_array( $value ) ) {
 589                                         $out[$key] = self::arrayMerge( $out[$key], $value );
 590                                 } elseif ( !isset( $out[$key] ) || !$out[$key] && !is_numeric( $key ) ) {
 591                                         // Values that evaluate to true given precedence, for the
 592                                         // primary purpose of merging permissions arrays.
 593                                         $out[$key] = $value;
 594                                 } elseif ( is_numeric( $key ) ) {
 595                                         $out[] = $value;
 596                                 }
 597                         }
 598                 }
 599
 600                 return $out;
 601         }
 602
 603         public function loadFullData() {
 604                 if ( $this->fullLoadCallback && !$this->fullLoadDone ) {
 605                         call_user_func( $this->fullLoadCallback, $this );
 606                         $this->fullLoadDone = true;
 607                 }
 608         }
 609 }