PHP 5.5 has been released and it features a new code caching module called OPCache, but there doesn't appear to be any documentation for it.
So where is the documentation for it and how do I use OPcache?
Answer
Installation
OpCache is compiled by default on PHP5.5+. However it is disabled by default. In order to start using OpCache in PHP5.5+ you will first have to enable it. To do this you would have to do the following.
Add the following line to your php.ini:
zend_extension=/full/path/to/opcache.so (nix)
zend_extension=C:\path\to\php_opcache.dll (win)
Note that when the path contains spaces you should wrap it in quotes:
zend_extension="C:\Program Files\PHP5.5\ext\php_opcache.dll"
Also note that you will have to use the zend_extension directive instead of the "normal" extension directive because it affects the actual Zend engine (i.e. the thing that runs PHP).
Usage
Currently there are four functions which you can use:
opcache_get_configuration():
Returns an array containing the currently used configuration OpCache uses. This includes all ini settings as well as version information and blacklisted files.
var_dump(opcache_get_configuration());
opcache_get_status():
This will return an array with information about the current status of the cache. This information will include things like: the state the cache is in (enabled, restarting, full etc), the memory usage, hits, misses and some more useful information. It will also contain the cached scripts.
var_dump(opcache_get_status());
opcache_reset():
Resets the entire cache. Meaning all possible cached scripts will be parsed again on the next visit.
opcache_reset();
opcache_invalidate():
Invalidates a specific cached script. Meaning the script will be parsed again on the next visit.
opcache_invalidate('/path/to/script/to/invalidate.php', true);
Maintenance and reports
There are some GUI's created to help maintain OpCache and generate useful reports. These tools leverage the above functions.
OpCacheGUI
Disclaimer I am the author of this project
Features:
- OpCache status
- OpCache configuration
- OpCache statistics
- OpCache reset
- Cached scripts overview
- Cached scripts invalidation
- Multilingual
- Mobile device support
- Shiny graphs
Screenshots:
URL: https://github.com/PeeHaa/OpCacheGUI
opcache-status
Features:
- OpCache status
- OpCache configuration
- OpCache statistics
- Cached scripts overview
- Single file
Screenshot:
URL: https://github.com/rlerdorf/opcache-status
opcache-gui
Features:
- OpCache status
- OpCache configuration
- OpCache statistics
- OpCache reset
- Cached scripts overview
- Cached scripts invalidation
- Automatic refresh
Screenshot:
