PHP OpCache implementation of PSR-16 Simple Cache Interface
A PSR-16 Simple Cache Implementation.
PHP is an interpreted language. The default PHP runtime compiles PHP sourcecode to an intermediate representation called PHP bytecode which is then executed. A bytecode cache stores this compiled representation of PHP sourcecode in shared memory. This eliminates the need to load and compile sourcecode on each request which leads to a significant increase in performance (up to 70% more requests per second).
The basic idea, when executing a PHP script is in two steps:
- First: the PHP code, written in plain-text, is compiled to opcodes
- Then: those opcodes are executed.
When you have one PHP script, as long as it is not modified, the opcodes will always be the same ; so, doing the compilation phase each time that script is to be executed is kind of a waste of CPU-time.
To prevent that redundant-compilation, there are some opcode caching mechanism that you can use.
Once the PHP script has been compiled to opcodes, those will be kept in RAM -- and directly used from memory the next time the script is to be executed ; preventing the compilation from being done again and again.
composer require odan/cache
$cachePath = sys_get_temp_dir() . '/cache'; $cache = new \Odan\Cache\Simple\OpCache($cachePath); // set a opcache value $cache->set('foo', 'bar'); // get a opcache value echo $cache->get('foo'); // bar
Fatal error: Call to undefined method stdClass::__set_state()
If there are objects in the value, they will be written as
This is fine for objects where __set_state() can be added, but it can't be added to stdClass.
To fix this issue just serialize the value you are trying to cache:
Then unserialize the string back to the original value:
$object = unserialize($cache->get('key'));
If you're in a high-concurrency environment you should avoid using a filesystem cache. Multiple operations on the file system are very hard to make atomic in PHP.