PHP file cache class implementation code, _PHP tutorial

PHP file cache class implementation code,

caching classification in php database cache, file cache and memory cache, let me follow I will give you a detailed introduction to the PHP file cache class implementation code. Friends who need to know more can refer to it.
Page cache class
The code is as follows:

<&#63;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;  
 }  
}  
&#63;> 

The above usage is regarded as page caching. Every time you access a page, it will first detect whether the corresponding cached page file exists. If it does not exist, connect to the database, get the data, display the page and generate the cached page file at the same time. Like this The page file comes into play during the first visit. (Template engines and some common caching 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

<&#63;php
$memcache = new Memcache;
$memcache->connect('localhost', 11211) or die ("Could not connect");
$version = $memcache->getVersion();
echo "Server's version: ".$version."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");
echo "Store data in the cache (data will expire in 10 seconds)n";
$get_result = $memcache->get('key');
echo "Data from the cache:n";
var_dump($get_result);
&#63;>

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

The above is the entire content of this article. I hope it will be helpful to everyone in learning php caching.

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