Cache classification database cache in php-PHP Tutorial-php.cn

This article mainly introduces the cache classification database cache in php. Interested friends can refer to it. I hope it will be helpful to everyone.

Page cache class

The code is as follows:

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<?php  
/*include( "cache.php" );  
   
$cache = new cache(30);  
$cache->cacheCheck();  
   
echo date("Y-m-d H:i:s");  
   
$cache->caching(); */
class cache {  
 //缓存目录  
 var $cacheRoot    = "./cache/";  
 //缓存更新时间秒数，0为不缓存  
 var $cacheLimitTime  = 3; 
 //缓存文件名  
 var $cacheFileName  = "";  
 //缓存扩展名  
 var $cacheFileExt   = "php";  
    
 /*  
  * 构造函数  
  * int $cacheLimitTime 缓存更新时间  
  */ 
 function cache( $cacheLimitTime ) {  
  if( intval( $cacheLimitTime ) )   
   $this->cacheLimitTime = $cacheLimitTime;  
  $this->cacheFileName = $this->getCacheFileName();  
  ob_start();  
 }  
    
 /*  
  * 检查缓存文件是否在设置更新时间之内  
  * 返回：如果在更新时间之内则返回文件内容，反之则返回失败  
  */ 
 function cacheCheck(){  
  if( file_exists( $this->cacheFileName ) ) {  
   $cTime = $this->getFileCreateTime( $this->cacheFileName );  
   if( $cTime + $this->cacheLimitTime > time() ) {  
    echo file_get_contents( $this->cacheFileName );  
    ob_end_flush();  
    exit;  
   }  
  }  
  return false;  
 }  
    
 /*  
  * 缓存文件或者输出静态  
  * string $staticFileName 静态文件名（含相对路径）  
  */ 
 function caching( $staticFileName = "" ){  
  if( $this->cacheFileName ) {  
   $cacheContent = ob_get_contents();  
   //echo $cacheContent;  
   ob_end_flush();  
    
   if( $staticFileName ) {  
     $this->saveFile( $staticFileName, $cacheContent );  
   }  
    
   if( $this->cacheLimitTime )  
    $this->saveFile( $this->cacheFileName, $cacheContent );  
  }  
 }  
    
 /*  
  * 清除缓存文件  
  * string $fileName 指定文件名(含函数)或者all（全部）  
  * 返回：清除成功返回true，反之返回false  
  */ 
 function clearCache( $fileName = "all" ) {  
  if( $fileName != "all" ) {  
   $fileName = $this->cacheRoot . strtoupper(md5($fileName)).".".$this->cacheFileExt;  
   if( file_exists( $fileName ) ) {  
    return @unlink( $fileName );  
   }else return false;  
  }  
  if ( is_dir( $this->cacheRoot ) ) {  
   if ( $dir = @opendir( $this->cacheRoot ) ) {  
    while ( $file = @readdir( $dir ) ) {  
     $check = is_dir( $file );  
     if ( !$check )  
     @unlink( $this->cacheRoot . $file );  
    }  
    @closedir( $dir );  
    return true;  
   }else{  
    return false;  
   }  
  }else{  
   return false;  
  }  
 }  
    
 /*  
  * 根据当前动态文件生成缓存文件名  
  */ 
 function getCacheFileName() {  
  return $this->cacheRoot . strtoupper(md5($_SERVER["REQUEST_URI"])).".".$this->cacheFileExt;  
 }  
    
 /*  
  * 缓存文件建立时间  
  * string $fileName  缓存文件名（含相对路径）  
  * 返回：文件生成时间秒数，文件不存在返回0  
  */ 
 function getFileCreateTime( $fileName ) {  
  if( ! trim($fileName) ) return 0;  
    
  if( file_exists( $fileName ) ) {   
   return intval(filemtime( $fileName ));  
  }else return 0;  
 }  
    
 /*  
  * 保存文件  
  * string $fileName 文件名（含相对路径）  
  * string $text   文件内容  
  * 返回：成功返回ture，失败返回false  
  */ 
 function saveFile($fileName, $text) {  
  if( ! $fileName || ! $text ) return false;  
    
  if( $this->makeDir( dirname( $fileName ) ) ) {  
   if( $fp = fopen( $fileName, "w" ) ) {  
    if( @fwrite( $fp, $text ) ) {  
     fclose($fp);  
     return true;  
    }else {  
     fclose($fp);  
     return false;  
    }  
   }  
  }  
  return false;  
 }  
    
 /*  
  * 连续建目录  
  * string $dir 目录字符串  
  * int $mode  权限数字  
  * 返回：顺利创建或者全部已建返回true，其它方式返回false  
  */ 
 function makeDir( $dir, $mode = "0777" ) {  
  if( ! $dir ) return 0;  
  $dir = str_replace( "", "/", $dir );  
     
  $mdir = "";  
  foreach( explode( "/", $dir ) as $val ) {  
   $mdir .= $val."/";  
   if( $val == ".." || $val == "." || trim( $val ) == "" ) continue;  
      
   if( ! file_exists( $mdir ) ) {  
    if(!@mkdir( $mdir, $mode )){  
     return false;  
    }  
   }  
  }  
  return true;  
 }  
}  
?>

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The above usage is regarded as page caching. Every time the page is accessed, the corresponding page will be detected first. Whether the cached page file exists, if not, connect to the database, get the data, display the page and generate the cached page file at the same time, so that the page file will play a role the next time you visit. (Template engines and some common cache classes on the Internet usually have this function)
Let me introduce to you a Memcache cache, which is regarded as a memory cache.
The code is as follows

<?php
$memcache = new Memcache;
$memcache->connect(&#39;localhost&#39;, 11211) or die ("Could not connect");
$version = $memcache->getVersion();
echo "Server&#39;s version: ".$version."n";
$tmp_object = new stdClass;
$tmp_object->str_attr = &#39;test&#39;;
$tmp_object->int_attr = 123;
$memcache->set(&#39;key&#39;, $tmp_object, false, 10) or die ("Failed to save data at the server");
echo "Store data in the cache (data will expire in 10 seconds)n";
$get_result = $memcache->get(&#39;key&#39;);
echo "Data from the cache:n";
var_dump($get_result);
?>

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Memcached is a high-performance, distributed memory object caching system used to reduce database load and improve access speed in dynamic applications.

Summary: The above is the entire content of this article, I hope it will be helpful to everyone's study.

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