Simple PHP Cache

About

A light, simple but powerful PHP5 Cache Class which uses the filesystem for caching.
Your feedback is always welcome.

Requirements

PHP 5.2.x or higher

Introduction

Basically the caching class stores its data in files in the JSON format. These files will be created if you store data under a Cache name.

If you set a new Cache name with setCache(), a new cache file will be generated. The Cache will store all further data in the new file. The Setter method allows you to switch between the different Cache files.

Quick Start

Setup Cache class

It's not much trouble to setup the Cache.
First create a writable directory cache/ and include the Cache class:

<?php
    require_once 'cache.class.php';
    
    // setup 'default' cache
    $c = new Cache();
?>

Now we've setup the Cache instance and can start caching!

<?php
    // store a string
    $c->store('hello', 'Hello World!');
    
    // generate a new cache file with the name 'newcache'
    $c->setCache('newcache');
    
    // store an array
    $c->store('movies', array(
      'description' => 'Movies on TV',
      'action' => array(
        'Tropic Thunder',
        'Bad Boys',
        'Crank'
      )
    ));
    
    // get cached data by its key
    $result = $c->retrieve('movies');
    
    // display the cached array
    echo '<pre>';
    print_r($result);
    echo '<pre>';
    
    // grab array entry
    $description = $result['description'];
    
    // switch back to the first cache
    $c->setCache('mycache');
    
    // update entry by simply overwriting an existing key
    $c->store('hello', 'Hello everybody out there!');
    
    // erase entry by its key
    $c->erase('hello');
?>

You can also make use of the Method Chaining feature, introduced in PHP5.
So you can do something like that:

<?php
    $c->setCache('mycache')      // generate new file
      ->store('hello', 'world')  // store data string
      ->retrieve('hello');       // retrieve cached data
?>

Available methods

Setup the Cache

new Cache(<array>/<string>)

string gives you the basic setup.
It's the name of your Cache (standard Cache name is 'default'):

new Cache('YOUR-CACHE-NAME');

array allows you to define multiple optional parameters:

new Cache(array(
  'name'      => 'YOUR-CACHE-NAME',
  'path'      => 'cache/',
  'extension' => '.cache'
));

If you don't define a Cache name with the constructor or the setCache() method, it'll be 'default'.

Store data

store($key, $data, <$expiration>)

The key value defines a tag with which the cached data will be associated.
The data value can be any type of object (will be serialized).
The expiration value allows you to define an expiration time.

To change data you can overwrite it by using the same key identifier.
Beside the data, the Cache will also store a timestamp.

A sample Cache entry looks like this:

{
  "christmas": {
    "time": 1324664631,
    "expire": 28000,
    "data": "s:29:"A great time to bake cookies.";" // serialized
  }
}

Retrieve data

retrieve($key, <$timestamp>)

Get particular cached data by its key.
To retrieve the timestamp of a key, set the second parameter to true.

retrieveAll(<$meta>)

This allows you retrieve all the cached data at once. You get the meta data by setting the $meta argument to true.

Erase data

For erasing cached data are these four methods available:

erase($key) Erases a single entry by its key.
eraseAll() Erases all entries from the Cache file.
eraseExpired() Erases all expired entries.

<?php
    // returns the count of erased entries  
    echo $c->eraseExpired() . ' expired items erased!';
?>

autoEraseExpired(<$flag>) Erases items automatically when calling isCached(), retreive(), and retreiveAll()

Check cached data

isCached($key)

Check whether any data is associated with the given key.
Returns true or false.

Set Cache name

setCache($name)

If you want to switch to another Cache or create a new one, then use this method to set a new Cache name.

Set Cache path

setCachePath($path)

The path to the Cache folder must end with a backslash: my_path_to_the_cache_folder/

Get Cache file path

getCacheDir()

The method returns the path to your current Cache file (the Cache name is always sh1 encoded):

cache/7505d64a54e061b7acd54ccd58b49dc43500b635.cache

Benchmarks

If you've done one, please let me know.

History

Upcoming: Simple Cache 2.0
Implementation of an internal "soft cache", hash-sum handling and the switch to serialization. Thanks @dariushha for his contribution!

Simple Cache 1.6 - 04/01/2014

update Updated docs.
bug Fixed retrieveAll() method to unserialize data.

Simple Cache 1.5 - 01/01/2014

feature added serialize / unserialize to store any kind of data.

Simple Cache 1.4 - 08/09/2013

bug Fixed loading file twice in store() method.
bug Fixed retrieve() method - made it fail safe (thanks @dariushha).

Simple Cache 1.3 - 28/02/2013

update Updated docs for the added retrieveAll() method.
feature Added retrieveAll() method (thanks @rpnzl).

Simple Cache 1.2 - 09/05/2012

update Formatted code
bug Fixed isCached() method so that it works as expected (thanks @TigerWolf).

Simple Cache 1.1 - 01/01/2012

change The extension config has to start now with a dot.
feature Added expiration handling to the store() method
feature Added the methods eraseExpired() and eraseAll()
feature Added method to make sure that a writable directory exists

Simple Cache 1.0 - 29/12/2011

release First public version
feature Added timestamp option to the retrieve() method

Simple Cache 0.9 - 25/12/2011

update Added Quick Start guide to the documentation
feature Added Method Chaining possibility
bug Fixed constructor configuration string/array handling

Simple Cache 0.8 - 24/12/2011

release First internal beta version (tested)
feature Added Setter and Getter methods
update Detailed documentation

Simple Cache 0.5 - 22/12/2011

release First internal alpha version
update Small documentation

timgws/Simple-PHP-Cache