PHP is used as the memcached client.

Through the introduction in previous articles, we can know the specific working principle of memcached. So, today we will show you how to implementYou can use PHP as the memcached client to call the memcached service for object access.

 
 

  
  
<?Php 
  
  
// Contains the memcached class file
  
  
Require_once ('memcached-client. php ');
  
  
// Option settings
  
  
$Options=Array(
  
  
'Servers' =>Array ('192. 168.1.1: 100'), // address and port of the memcached service. Multiple array elements can be used to represent multiple memcached services.
  
  
'Debug' =>True, // whether to enable debug
  
  
'Compress _ threshold '=>10240, // how many bytes of data are compressed
  
  
'Persistant' =>False // whether to use persistent connection
  
  
);
  
  
// Create a memcached object instance
  
  
$Mc=NewMemcached ($ options );
  
  
// Set the unique identifier used by this script
  
  
$Key='Mykey';
  
  
// Write an object to memcached
  
  
$ Mc->Add ($ key, 'some random string ');
  
  
$Val= $ Mc->Get ($ key );
  
  
Echo "n". str_pad ('$ mc->Add () ', 60,' _ '). "n ";
  
  
Var_dump ($ val );
  
  
// Replace the written object data value
  
  
$ Mc->Replace ($ key, array ('some' =>'Hahaha', 'array' =>'Xxx '));
  
  
$Val= $ Mc->Get ($ key );
  
  
Echo "n". str_pad ('$ mc->Replace () ', 60,' _ '). "n ";
  
  
Var_dump ($ val );
  
  
// Delete an object in memcached
  
  
$ Mc->Delete ($ key );
  
  
$Val= $ Mc->Get ($ key );
  
  
Echo "n". str_pad ('$ mc->Delete () ', 60,' _ '). "n ";
  
  
Var_dump ($ val );
  
  
?> 
 
 

The first PHP method is used as the memcached client. PHP has an extension called memcache. during compilation in Linux, the "-enable-memcache [= DIR]" option is required, and the "Window" method is in php. remove the annotator in front of php_memcache.dll in ini to make it available.

In addition, there is also a way to avoid the trouble of extension and re-compilation, that is, directly using php-memcached-client.

The second method is used in this article. Although the efficiency is slightly lower than that of the extended library, it is not a problem.

First download the memcached-client.php, after downloading the memcached-client.php, you can operate the memcached service through the class "memcached" in this file. In fact, code calls are very simple. The main methods used include add (), get (), replace (), and delete (). The methods are described as follows:

Add ($ key, $ val, $ exp = 0)

Write an object to memcached. $ key is the unique identifier of the object. $ val is the data of the written object. $ exp is the expiration time, in seconds. The default value is unlimited;

Get ($ key)

Get object data from memcached and get it through the unique identifier $ key of the object;

Replace ($ key, $ value, $ exp = 0)

Replace $ value with the content of the $ key object in memcached. The parameter works only when the $ key object exists like the add () method;

Delete ($ key, $ time = 0)

Delete an object with the identifier $ key in memcached. $ time is an optional parameter, indicating how long it will take before deletion.

The following is a simple test code that allows you to access the object data with the identifier 'mykey:

PHP is easy to implement as a memcached client. In actual applications, the database query result set is usually saved to memcached, which is obtained directly from memcached during the next visit, instead of performing database query operations, this can greatly reduce the burden on the database. Generally, the value after the md5 () of the SQL statement is used as the unique identifier key. Below is an example of using memcached to cache the database query result set (this code snippet is followed by the above sample code ):

 
 

  
  
<?Php 
  
  
$SQL='Select * FROM users';
  
  
$Key=Md5($ SQL); // memcached object identifier
  
  
If (! ($Datas= $ Mc->Get ($ key ))){
  
  
// If no cached data is obtained in memcached, use database query to obtain the record set.
  
  
Echo "n". str_pad ('read datas from MySQL. ', 60,' _ '). "n ";
  
  
$Conn=Mysql_connect('Localhost', 'test', 'test ');
  
  
Mysql_select_db ('test ');
  
  
$Result=Mysql_query($ SQL );
  
  
While ($Row=Mysql_fetch_object($ Result ))
  
  
$ Datas [] = $ row;
  
  
// Save the result set data obtained from the database to memcached for the next access.
  
  
$ Mc->Add ($ key, $ datas );
  
  
} Else {
  
  
Echo "n". str_pad ('read datas from memcached. ', 60,' _ '). "n ";
  
  
}
  
  
Var_dump ($ datas );
  
  
?> 
 
 

As you can see, after using PHP as the memcached client, you can reduce database connection and query operations, load the database, and speed up the running of scripts.