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LXX. Memcache Functions


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.

This module doesn't have native support of multiple servers, but you still can implement it yourself in your application. Establish several memcached connections, set priority level for each server etc.

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


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 the memcache extension.


PECL 扩展未绑定于 PHP 中。 进一步信息例如新版本,下载,源程序,维护者信息以及更新日志可以在此找到: http://pecl.php.net/package/memcache.

In order to use these functions you must compile PHP with MemCache support by using the --with-memcache[=DIR] option.

Windows users will enable php_memcache.dll inside of php.ini in order to use these functions. 可以从 PHP 下载页面或者 http://snaps.php.net/ 下载此 PECL 扩展的 DLL 文件。


表格 1. MemCache Constants

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


本扩展模块在 php.ini 中未定义任何设置指令。


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

例子 1. memcache extension overview example


= new Memcache;
$memcache->connect('localhost', 11211) or die ("Could not connect");

$version = $memcache->getVersion();
"Server's version: ".$version."<br/>\n";

$tmp_object = new stdClass;
$tmp_object->str_attr = 'test';
$tmp_object->int_attr = 123;

$memcache->set('key', $tmp_object, false, 10) or die ("Failed to save data at the server");
"Store data in the cache (data will expire in 10 seconds)<br/>\n";

$get_result = $memcache->get('key');
"Data from the cache:<br/>\n";



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.

Memcache::add -- Add an item to the server
Memcache::close -- Close memcached server connection
Memcache::connect -- Open memcached server connection
memcache_debug -- Turn debug output on/off
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