Manual:ParserCache.php
| MediaWiki file: ParserCache.php | |
|---|---|
| Location: | includes/parser/ |
| Source code: | master • 1.42.3 • 1.41.4 • 1.39.10 |
| Classes: | ParserCache |
Class for caching rendered output, i.e. HTML as well as associated data, for the latest revision of a page.
Main features
[edit]For detailed information, see Manual:Parser cache. This is a summary:
- supports 'varying keys', i.e. the use of different cache keys for a page or revision, based on certain 'options'.
- because of this, supports the use of multiple ParserCache instances so that multiple cache entries can exist side by side (MW 1.36+).
- consists of two tiers, each stored with its own key, to avoid cache fragmentation that may happen as a result of having multiple cache entries:
- one containing a CacheTime object for holding metadata about cache expiration and parsing 'options'. Metadata can be retrieved using getMetadata().
- another containing the ParserOutput object, with values from the options specified in the metadata of the first tier. It can be retrieved with getDirty() or get().
- allows for cache to be created ('populated')
- allows for cache to be removed/replaced:
- after the revision timestamp is updated and the cache entry is invalidated (marked as 'dirty')
- after it expires. The removal of expired entries is called 'pruning'. See also ParserOutput::updateCacheExpiry().
- when there are reasons for enforcing it (e.g. cache optimisation), in which case the process of removal is called 'eviction'.
Instantiation
[edit]MediaWikiServices::getInstance()->getParserCache()
Public methods
[edit]Public methods not for internal use only include:
- getDirty() - retrieve the ParserOutput from ParserCache, even if it is outdated.
- get() - retrieve the ParserOutput from ParserCache; false if not found or outdated.
- getMetadata() - return the ParserCache metadata about the given page considering the given options.
- save() - store ParserCache object.
- deleteOptionsKey()