PHP memory cache implementation program code_PHP tutorial

Caching in php is divided into many types, such as memory caching, file caching, and page caching. This article will talk about some methods of memory caching in php. Below we introduce the Memcached cache and the APC caching method that comes with PHP.

1.Memcached cache.
Memcached is a high-performance distributed memory cache server that caches database query results and reduces the number of database accesses to increase the speed of dynamic web applications. memcached uses the "Key=>Value" method to organize data. It allows multiple users on different hosts to access this cache system at the same time, and is generally used for large websites. Memcached uses memory to cache data, so it is volatile. When the server is restarted or the memcached process is terminated, the data will be lost, so memcached cannot be used to persist data.

Anyone who has experienced php_memcache will think that PHP memory cache is a very complicated thing, but it is not.
Memcached is an efficient and fast distributed memory object caching system, mainly used to accelerate WEB dynamic applications.
Here we introduce the configuration and use of memcached under WIN32.

1. PHP memory cache configuration (WIN32 environment)

1. Download php_memcache.rar, please download from the attachment.

Decompress the compressed package: php_memcache.rar

The main files included in the php_memcache.rar compressed package are:

/memcached-1.2.1-win32/memcached.exe
/php_memcache/php_memcache.dll

2. Open the command prompt, point to the path where memcached.exe is located, and run memcached.exe -d start.

3. Copy the php_memcache.dll file to the folder of PHP’s dynamic file library.

4. Add a line extension=php_memcache.dll to the php.ini file.

5. Restart Apache, and then check phpinfo. If there is memcache, it means the installation is successful!

Example:

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代码如下

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//包含 memcached 类文件 require_once('memcached-client.php');   //选项设置 $options = array(  'servers' => array('www.hxsd.com:11211'),//memcached 服务的地址、端口  'debug' => true,//是否打开debug  'compress_threshold' => 10240,//超过多少字节的数据时进行压缩  'persistant' => false//是否使用持久连接  );   //实例化memcached对象 $memcached = new memcached($options);   $sql = 'SELECT * FROM table1'; $key = md5($sql);   //如果在memcached中没有缓存数据,把缓存数据写入memcached if(!($datas = $memcached->get($key))) {  $conn = mysql_connect('localhost', 'hxsd', '123456');  mysql_select_db('hxsd');  $result = mysql_query($sql);  while($row = mysql_fetch_object($result))  {   $datas[] = $row;  }  //将数据库中获取到的结果集数据保存到 memcached 中，以供下次访问时使用。  $memcached->add($key, $datas); } else {  //直接使用memcached中的缓存数据$datas } ?>

//Contains memcached class filerequire_once('memcached-client.php');

//Option settings

$options = array(

'servers' => array('www.hxsd.com:11211'),//The address and port of the memcached service

' debug' => true,//Whether to turn on debug

'compress_threshold' => 10240,//Compress when the data exceeds the number of bytes

'persistant' => false//Whether to use persistent connections

);

//Instantiate memcached object

$memcached = new memcached($options);

$sql = 'SELECT * FROM table1';

$ key = md5($sql);

//If there is no cached data in memcached, write the cached data to memcached

if(!($datas = $memcached->get($key) ))

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# pecl install APC

{ $conn = mysql_connect('localhost', 'hxsd', '123456'); mysql_select_db('hxsd'); $result = mysql_query($sql); while($row = mysql_fetch_object($result)) { $datas[] = $row; } //Save the result set data obtained from the database into memcached , for your next visit. $memcached->add($key, $datas);}else{ //Use cached data directly in memcached $datas} ?> APC, the full name is Alternative PHP Cache, and the official translation is called "Optional PHP Cache". The homepage is http://pecl.php.net/package/apcphp help manual page: http://cn.php.net/apcAPC is an optimizer. From the day of installation, it has been silently serving your PHP application in the background. All your PHP codes will be cached. (For php opcode) In addition, APC It can provide a certain memory cache function. However, this function is not perfect. There are reports that if the write function of APC cache is used frequently, it will cause unpredictable errors. If you want to use this function, you can take a look at apc_fetch, apc_store, etc. APC cache related functions.Installation:

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# pecl install APC

配置：（/etc/php.inc）

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extension=apc.so

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apc.enabled = 1 apc.shm_segments = 1 apc.shm_size = 30 apc.optimization = 0 apc.ttl = 7200 apc.user_ttl = 7200 apc.num_files_hint = 1000 apc.mmap_file_mask = /tmp/apc.XXXXXX

extension=apc.so

[apc]

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apc.enabled = 1apc.shm_segments = 1apc.shm_size = 30apc.optimization = 0apc.ttl = 7200apc.user_ttl = 7200apc.num_files_hint = 1000 apc.mmap_file_mask = /tmp/apc.XXXXXX http://www.bkjia.com/PHPjc/444642.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/444642.htmlTechArticle在php中缓存分为很多种类型如，内存缓存，文件缓存，页面缓存本文章要来讲述关于php中内存缓存的一些方法，下面我们介绍Memcached缓存和...