LIX. Memcache Functions

Introduction

Memcache module provides handy procedural and object oriented interface to memcached, highly effective caching daemon, which was especially designed to decrease database load in dynamic web applications.

More information about memcached can be found at http://www.danga.com/memcached/.

Requirements

This module uses functions of zlib to support on-the-fly data compression. Zlib is required to install this module.

PHP 4.3.3 or newer is required to use memcache extension.

Installation

Memcache is currently available through PECL http://pecl.php.net/package/memcache.

Also you can use the pear installer to install the memcache extension, using the following command: pear -v install memcache.

You can always download the tar.gz package and install memcache by hand:
Esimerkki 1. Memcache installation
gunzip memcache-xxx.tgz tar -xvf memcache-xxx.tar cd memcache-xxx phpize ./configure && make && make install

Windows users can download the extension dll php_memcache.dll here: http://snaps.php.net/win32/PECL_STABLE/.

Resource Types

There is only one resource type used in memcache module - it's the link identifier for a cache server connection.

Predefined Constants

MEMCACHE_COMPRESSED (integer): Used to turn on-the-fly data compression on with Memcache::set(), Memcache::add() and Memcache::replace().

Examples

Esimerkki 2. memcache extension overview example
<?php $memcache = new Memcache; $memcache->connect('localhost', 11211) or die ("Could not connect"); $version = $memcache->getVersion(); echo "Server's version: ".$version."<br/>\n"; $tmp_object = new stdClass; $tmp_object->str_attr = 'test'; $tmp_object->int_attr = 123; $memcache->set('key', $tmp_object, 10) or die ("Failed to save data at the server"); echo "Store data in the cache (data will expire in 10 seconds)<br/>\n"; $get_result = $memcache->get('key'); echo "Data from the cache:<br/>\n"; var_dump($get_result); ?>

In the above example, an object is being saved in the cache and then retrieved back. Object and other non-scalar types are serialized before saving, so it's impossible to store resources (i.e. connection identifiers and others) in the cache.

Sisällys
Memcache::add -- Add an item to the server
Memcache::close -- Close memcached server connection
Memcache::connect -- Open memcached server connection
Memcache::decrement -- Decrement item's value
Memcache::delete -- Delete item from the server
Memcache::flush -- Flush all existing items at the server
Memcache::get -- Retrieve item from the server
Memcache::getStats -- Get statistics of the server
Memcache::getVersion -- Return version of the server
Memcache::increment -- Increment item's value
Memcache::pconnect -- Open memcached server persistent connection
Memcache::replace -- Replace value of the existing item
Memcache::set -- Store data at the server
memcache_debug -- Turn debug output on/off