/**
* Constructs a cache key to use for caching the list of sites.
*
* This includes the concrete class name of the site list as well as a version identifier
* for the list's serialization, to avoid problems when unserializing site lists serialized
* by an older version, e.g. when reading from a cache.
*
* The cache key also includes information about where the sites were loaded from, e.g.
* the name of a database table.
*
* @see SiteList::getSerialVersionId
*
* @return String The cache key.
*/
protected function getCacheKey()
{
wfProfileIn(__METHOD__);
if ($this->cacheKey === null) {
$type = 'SiteList#' . SiteList::getSerialVersionId();
$source = $this->sitesTable->getName();
if ($this->sitesTable->getTargetWiki() !== false) {
$source = $this->sitesTable->getTargetWiki() . '.' . $source;
}
$this->cacheKey = wfMemcKey("{$source}/{$type}");
}
wfProfileOut(__METHOD__);
return $this->cacheKey;
}
