includes/config/SiteConfiguration.php
<?php
/**
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
*/
namespace MediaWiki\Config;
/**
* Configuration holder, particularly for multi-wiki sites.
*
* A basic synopsis:
*
* Consider a wikifarm having three sites: two production sites, one in English
* and one in German, and one testing site. You can assign them easy-to-remember
* identifiers - ISO 639 codes 'en' and 'de' for language wikis, and 'beta' for
* the testing wiki.
*
* You would thus initialize the site configuration by specifying the wiki
* identifiers:
*
* @code
* $conf = new SiteConfiguration;
* $conf->wikis = [ 'de', 'en', 'beta' ];
* @endcode
*
* When configuring the MediaWiki global settings (the $wg variables),
* the identifiers will be available to specify settings on a per wiki basis.
*
* @code
* $conf->settings = [
* 'wgSomeSetting' => [
*
* # production:
* 'de' => false,
* 'en' => false,
*
* # test:
* 'beta => true,
* ],
* ];
* @endcode
*
* With three wikis, that is easy to manage. But what about a farm with
* hundreds of wikis? Site configuration provides a special keyword named
* 'default' which is the value used when a wiki is not found. Hence
* the above code could be written:
*
* @code
* $conf->settings = [
* 'wgSomeSetting' => [
*
* 'default' => false,
*
* # Enable feature on test
* 'beta' => true,
* ],
* ];
* @endcode
*
*
* Since settings can contain arrays, site configuration provides a way
* to merge an array with the default. This is very useful to avoid
* repeating settings again and again while still maintaining specific changes
* on a per wiki basis.
*
* @code
* $conf->settings = [
* 'wgMergeSetting' = [
* # Value that will be shared among all wikis:
* 'default' => [ NS_USER => true ],
*
* # Leading '+' means merging the array of value with the defaults
* '+beta' => [ NS_HELP => true ],
* ],
* ];
*
* # Get configuration for the German site:
* $conf->get( 'wgMergeSetting', 'de' );
* // --> [ NS_USER => true ];
*
* # Get configuration for the testing site:
* $conf->get( 'wgMergeSetting', 'beta' );
* // --> [ NS_USER => true, NS_HELP => true ];
* @endcode
*
* Finally, to load all configuration settings, extract them in global context:
*
* @code
* # Name / identifier of the wiki as set in $conf->wikis
* $wikiID = 'beta';
* $globals = $conf->getAll( $wikiID );
* extract( $globals );
* @endcode
*
* Simple suffix system where "pt_brwiki" becomes lang="pt-br", site="wiki":
*
* @code
* $conf->suffixes[] = 'wiki';
* @endcode
*
* Suffix is resolved as an alias, so "dewiki" becomes lang="de", site="wikipedia":
* @code
* $conf->suffixes['wikipedia'] = 'wiki';
* @endcode
*
* @note For WikiMap to function, the configuration must define string values for
* $wgServer (or $wgCanonicalServer) and $wgArticlePath, even if these are the
* same for all wikis or can be correctly determined by the logic in
* Setup.php.
*/
class SiteConfiguration {
/**
* Array of suffixes, for self::siteFromDB()
*/
public $suffixes = [];
/**
* Array of wikis, should be the same as $wgLocalDatabases
*/
public $wikis = [];
/**
* The whole array of settings.
*
* If the key "@replaceableSettings" exists, it contains a list of setting
* names that are subject to string replacement of $params.
*/
public $settings = [];
/**
* Optional callback to load full configuration data.
* @var string|array
*/
public $fullLoadCallback = null;
/** Whether or not all data has been loaded */
public $fullLoadDone = false;
/**
* A callback function that returns an array with the following keys (all
* optional):
* - suffix: site's suffix
* - lang: site's lang
* - tags: array of wiki tags
* - params: array of parameters to be replaced
* The function will receive the SiteConfiguration instance in the first
* argument and the wiki in the second one.
* if suffix and lang are passed they will be used for the return value of
* self::siteFromDB() and self::$suffixes will be ignored
*
* @var callable|null
*/
public $siteParamsCallback = null;
/**
* Configuration cache for getConfig()
* @var array
*/
protected $cfgCache = [];
/**
* Retrieves a configuration setting for a given wiki.
* @param string $settingName ID of the setting name to retrieve
* @param string $wiki Wiki ID of the wiki in question.
* @param string|null $site The site from ::siteFromDB(), or db suffix.
* @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
* @param array $wikiTags The tags assigned to the wiki.
* @return mixed The value of the setting requested.
*/
public function get(
$settingName,
$wiki,
$site = null,
$params = [],
$wikiTags = []
) {
$params = $this->mergeParams( $wiki, $site, $params, $wikiTags );
$overrides = $this->settings[$settingName] ?? null;
$value = $overrides ? $this->processSetting( $overrides, $wiki, $params['tags'] ) : null;
if ( !array_key_exists( '@replaceableSettings', $this->settings )
|| in_array( $settingName, $this->settings['@replaceableSettings'] )
) {
$this->doReplacements( $value, $params['replacements'] );
}
return $value;
}
/**
* Retrieve the configuration setting for a given wiki, based on an overrides array.
*
* General order of precedence:
*
* 1. Wiki ID, an override specific to the given wiki.
* 2. Tag, an override specific to a group of wikis (e.g. wiki family, or db
* shard). It is unsupported for the same setting to be set for multiple
* tags of which the wiki groups overlap. In that case, whichever is
* iterated and matched first wins, where the tag iteration order
* is NOT guaranteed.
* 3. Default, the default value for all wikis in this wiki farm.
*
* If the "+" operator is used, with any of these, then the merges will follow the
* following order (earlier entries have precedence on clashing sub keys):
*
* 1. "+wiki"
* 2. "tag"
* Only one may match here. And upon match, the merge cascade stops.
* 3. "+tag"
* These are only considered if there was no "tag" match.
* Multiple matches are allowed here, although the array values from
* multiple tags that contain the same wiki must not overlap, as it is
* undocumented how key conflicts among them would be handled.
* 4. "default"
*
* @param array $thisSetting An array of overrides for a given setting.
* @param string $wiki Wiki ID of the wiki in question.
* @param string[] $tags Array of tags.
* @return mixed The value of the setting requested.
*/
private function processSetting( $thisSetting, $wiki, $tags ) {
// Optimization: Avoid native type hint on private method called by hot getAll()
// <https://gerrit.wikimedia.org/r/c/mediawiki/core/+/820244>
$retval = null;
if ( array_key_exists( $wiki, $thisSetting ) ) {
// Found override by Wiki ID.
$retval = $thisSetting[$wiki];
} else {
if ( array_key_exists( "+$wiki", $thisSetting ) ) {
// Found mergable override by Wiki ID.
// We continue to look for more merge candidates.
$retval = $thisSetting["+$wiki"];
}
foreach ( $tags as $tag ) {
if ( array_key_exists( $tag, $thisSetting ) ) {
if ( is_array( $retval ) && is_array( $thisSetting[$tag] ) ) {
// Found a mergable override by Tag, without "+" operator.
// Merge it with any "+wiki" match from before, and stop the cascade.
$retval = self::arrayMerge( $retval, $thisSetting[$tag] );
} else {
// Found a non-mergable override by Tag.
// This could in theory replace a "+wiki" match, but it should never happen
// that a setting uses both mergable array values and non-array values.
$retval = $thisSetting[$tag];
}
return $retval;
} elseif ( array_key_exists( "+$tag", $thisSetting ) ) {
// Found a mergable override by Tag with "+" operator.
// Merge it with any "+wiki" or "+tag" matches from before,
// and keep looking for more merge candidates.
$retval = self::arrayMerge( $retval ?? [], $thisSetting["+$tag"] );
}
}
if ( array_key_exists( 'default', $thisSetting ) ) {
if ( is_array( $retval ) && is_array( $thisSetting['default'] ) ) {
// Found a mergable default
// Merge it with any "+wiki" or "+tag" matches from before.
$retval = self::arrayMerge( $retval, $thisSetting['default'] );
} else {
// Found a default
// If any array-based values were built up via "+wiki" or "+tag" matches,
// these are thrown away here. We don't support merging array values into
// non-array values, and the fallback here is to use the default.
$retval = $thisSetting['default'];
}
}
}
return $retval;
}
/**
* Do string replacements
*
* @param string &$value
* @param array $replacements
*/
private function doReplacements( &$value, $replacements ) {
// Optimization: Avoid native type hint on private method called by hot getAll()
// <https://gerrit.wikimedia.org/r/c/mediawiki/core/+/820244>
if ( is_string( $value ) ) {
$value = strtr( $value, $replacements );
} elseif ( is_array( $value ) ) {
foreach ( $value as &$val ) {
if ( is_string( $val ) ) {
$val = strtr( $val, $replacements );
}
}
}
}
/**
* Gets all settings for a wiki
* @param string $wiki Wiki ID of the wiki in question.
* @param string|null $site The site from ::siteFromDB(), or db suffix.
* @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
* @param array $wikiTags The tags assigned to the wiki.
* @return array Array of settings requested.
*/
public function getAll( $wiki, $site = null, $params = [], $wikiTags = [] ) {
$params = $this->mergeParams( $wiki, $site, $params, $wikiTags );
$tags = $params['tags'];
$localSettings = [];
foreach ( $this->settings as $varname => $overrides ) {
$value = $this->processSetting( $overrides, $wiki, $tags );
if ( $varname[0] === '+' ) {
$varname = substr( $varname, 1 );
if ( is_array( $value ) && is_array( $GLOBALS[$varname] ) ) {
$value = self::arrayMerge( $value, $GLOBALS[$varname] );
}
}
if ( $value !== null ) {
$localSettings[$varname] = $value;
}
}
$replacements = $params['replacements'];
if ( array_key_exists( '@replaceableSettings', $this->settings ) ) {
foreach ( $this->settings['@replaceableSettings'] as $varname ) {
if ( array_key_exists( $varname, $localSettings ) ) {
$this->doReplacements( $localSettings[$varname], $replacements );
}
}
} else {
foreach ( $localSettings as &$value ) {
$this->doReplacements( $value, $replacements );
}
}
return $localSettings;
}
/**
* Retrieves a configuration setting for a given wiki, forced to a boolean.
*
* @param string $setting ID of the setting name to retrieve
* @param string $wiki Wiki ID of the wiki in question.
* @param string|null $site The site from ::siteFromDB(), or db suffix.
* @param array $wikiTags The tags assigned to the wiki.
* @return bool The value of the setting requested.
*/
public function getBool( $setting, $wiki, $site = null, $wikiTags = [] ) {
return (bool)$this->get( $setting, $wiki, $site, [], $wikiTags );
}
/**
* Retrieves an array of local databases
*
* @return array
*/
public function getLocalDatabases() {
return $this->wikis;
}
/**
* Retrieves the value of a given setting, and places it in a variable passed by reference.
*
* @deprecated since 1.41 Use SiteConfiguration::get() instead.
* @param string $setting ID of the setting name to retrieve
* @param string $wiki Wiki ID of the wiki in question.
* @param string|null $site The site from ::siteFromDB(), or db suffix.
* @param array &$var Reference The variable to insert the value into.
* @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
* @param array $wikiTags The tags assigned to the wiki.
*/
public function extractVar(
$setting,
$wiki,
$site,
&$var,
$params = [],
$wikiTags = []
) {
wfDeprecated( __METHOD__, '1.41' );
$value = $this->get( $setting, $wiki, $site, $params, $wikiTags );
if ( $value !== null ) {
$var = $value;
}
}
/**
* Retrieves the value of a given setting, and places it in its corresponding global variable.
*
* @deprecated since 1.41 Use SiteConfiguration::get() instead.
* @param string $setting ID of the setting name to retrieve
* @param string $wiki Wiki ID of the wiki in question.
* @param string|null $site The site from ::siteFromDB(), or db suffix.
* @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
* @param array $wikiTags The tags assigned to the wiki.
*/
public function extractGlobal(
$setting,
$wiki,
$site = null,
$params = [],
$wikiTags = []
) {
wfDeprecated( __METHOD__, '1.41' );
$params = $this->mergeParams( $wiki, $site, $params, $wikiTags );
$this->extractGlobalSetting( $setting, $wiki, $params );
}
/**
* @param string $setting
* @param string $wiki
* @param array $params
*/
public function extractGlobalSetting( $setting, $wiki, $params ) {
$overrides = $this->settings[$setting] ?? null;
$value = $overrides ? $this->processSetting( $overrides, $wiki, $params['tags'] ) : null;
if ( !array_key_exists( '@replaceableSettings', $this->settings )
|| in_array( $setting, $this->settings['@replaceableSettings'] )
) {
$this->doReplacements( $value, $params['replacements'] );
}
if ( $value !== null ) {
if ( substr( $setting, 0, 1 ) == '+' && is_array( $value ) ) {
$setting = substr( $setting, 1 );
if ( is_array( $GLOBALS[$setting] ) ) {
$GLOBALS[$setting] = self::arrayMerge( $GLOBALS[$setting], $value );
} else {
$GLOBALS[$setting] = $value;
}
} else {
$GLOBALS[$setting] = $value;
}
}
}
/**
* Retrieves the values of all settings, and places them in their corresponding global variables.
* @param string $wiki Wiki ID of the wiki in question.
* @param string|null $site The site from ::siteFromDB(), or db suffix.
* @param array $params List of parameters. $.'key' is replaced by $value in all returned data.
* @param array $wikiTags The tags assigned to the wiki.
*/
public function extractAllGlobals(
$wiki,
$site = null,
$params = [],
$wikiTags = []
) {
$params = $this->mergeParams( $wiki, $site, $params, $wikiTags );
foreach ( $this->settings as $varName => $setting ) {
$this->extractGlobalSetting( $varName, $wiki, $params );
}
}
/**
* Return specific settings for $wiki
* See the documentation of self::$siteParamsCallback for more in-depth
* documentation about this function
*
* @param string $wiki
* @return array
*/
protected function getWikiParams( $wiki ) {
static $default = [
'suffix' => null,
'lang' => null,
'tags' => [],
'params' => [],
];
if ( !is_callable( $this->siteParamsCallback ) ) {
return $default;
}
$ret = ( $this->siteParamsCallback )( $this, $wiki );
# Validate the returned value
if ( !is_array( $ret ) ) {
return $default;
}
foreach ( $default as $name => $def ) {
if ( !isset( $ret[$name] ) || ( is_array( $def ) && !is_array( $ret[$name] ) ) ) {
$ret[$name] = $def;
}
}
return $ret;
}
/**
* Merge params between the ones passed to the function and the ones given
* by self::$siteParamsCallback for backward compatibility
* Values returned by self::getWikiParams() have the priority.
*
* @param string $wiki Wiki ID of the wiki in question.
* @param string|null $site The site from ::siteFromDB(), or db suffix.
* @param array $params List of parameters. $.'key' is replaced by $value in
* all returned data.
* @param array $wikiTags The tags assigned to the wiki.
* @return array
*/
protected function mergeParams( $wiki, $site, array $params, array $wikiTags ) {
$ret = $this->getWikiParams( $wiki );
$ret['suffix'] ??= $site;
// Make tags based on the db suffix (e.g. wiki family) automatically
// available for use in wgConf. The user does not have to maintain
// wiki tag lookups (e.g. dblists at WMF) for the wiki family.
$wikiTags[] = $ret['suffix'];
$ret['tags'] = array_unique( array_merge( $ret['tags'], $wikiTags ) );
$ret['params'] += $params;
// Make the $lang and $site parameters automatically available if they
// were provided by `siteParamsCallback` via getWikiParams()
if ( !isset( $ret['params']['lang'] ) && $ret['lang'] !== null ) {
$ret['params']['lang'] = $ret['lang'];
}
if ( !isset( $ret['params']['site'] ) && $ret['suffix'] !== null ) {
$ret['params']['site'] = $ret['suffix'];
}
// Optimization: For hot getAll() code path, precompute replacements to re-use
// over hundreds of processSetting() calls.
$ret['replacements'] = [];
// @phan-suppress-next-line PhanTypePossiblyInvalidDimOffset False positive
foreach ( $ret['params'] as $key => $value ) {
$ret['replacements']['$' . $key] = $value;
}
return $ret;
}
/**
* Work out the site and language name from a database name
*
* @param string $wiki Wiki ID
* @return array [ string|null $site, string|null $languageCode ]
*/
public function siteFromDB( $wiki ) {
// Allow override
$def = $this->getWikiParams( $wiki );
if ( $def['suffix'] !== null && $def['lang'] !== null ) {
return [ $def['suffix'], $def['lang'] ];
}
$languageCode = str_replace( '_', '-', $wiki );
foreach ( $this->suffixes as $altSite => $suffix ) {
if ( $suffix === '' ) {
return [ '', $languageCode ];
} elseif ( str_ends_with( $wiki, $suffix ) ) {
$site = is_string( $altSite ) ? $altSite : $suffix;
$languageCode = substr( $languageCode, 0, -strlen( $suffix ) );
return [ $site, $languageCode ];
}
}
return [ null, null ];
}
/**
* Merge multiple arrays together.
* On encountering duplicate keys, merge the two, but ONLY if they're arrays.
* PHP's array_merge_recursive() merges ANY duplicate values into arrays,
* which is not fun
*
* @param array $array1
* @param array $array2
* @return array
*/
private static function arrayMerge( array $array1, array $array2 ) {
$out = $array1;
foreach ( $array2 as $key => $value ) {
if ( isset( $out[$key] ) ) {
if ( is_array( $out[$key] ) && is_array( $value ) ) {
// Merge the new array into the existing one
$out[$key] = self::arrayMerge( $out[$key], $value );
} elseif ( is_numeric( $key ) ) {
// A numerical key is taken, append the value at the end instead.
// It is important that we generally preserve numerical keys and only
// fallback to appending values if there are conflicts. This is needed
// by configuration variables that hold associative arrays with
// meaningful numerical keys, such as $wgNamespacesWithSubpages,
// $wgNamespaceProtection, $wgNamespacesToBeSearchedDefault, etc.
$out[] = $value;
} elseif ( $out[$key] === false ) {
// A non-numerical key is taken and holds a false value,
// allow it to be overridden always. This exists mainly for the purpose
// merging permissions arrays, such as $wgGroupPermissions.
$out[$key] = $value;
}
// Else: The key is already taken and we keep the current value
} else {
// Add a new key.
$out[$key] = $value;
}
}
return $out;
}
public function loadFullData() {
if ( $this->fullLoadCallback && !$this->fullLoadDone ) {
( $this->fullLoadCallback )( $this );
$this->fullLoadDone = true;
}
}
}
/** @deprecated class alias since 1.41 */
class_alias( SiteConfiguration::class, 'SiteConfiguration' );