php文件缓存类用法实例分析

本文实例讲述了php文件缓存类用法。分享给大家供大家参考。具体如下：

<?php/** * 简单的文件缓存类 * */class XZCache{ // default cache time one hour var $cache_time = 3600; // default cache dir var $cache_dir = './cache'; public function __construct($cache_dir=null, $cache_time=null){  $this->cache_dir = isset($cache_dir) ? $cache_dir : $this->cache_dir;  $this->cache_time = isset($cache_time) ? $cache_time : $this->cache_time; } public function saveCache ($key, $value){  if (is_dir($this->cache_dir)){   $cache_file = $this->cache_dir . '/xzcache_' . md5($key);   $timedif = @(time() - filemtime($cache_file));   if ($timedif >= $this->cache_time) {    // cached file is too old, create new    $serialized = serialize($value);    if ($f = @fopen($cache_file, 'w')) {     fwrite ($f, $serialized, strlen($serialized));     fclose($f);    }   }   $result = 1;  }else{   echo "Error:dir is not exist.";   $result = 0;  }  return $result; } /**  * @return array   *   0 no cache  *    1 cached  *    2 overdue  */ public function getCache ($key) {  $cache_file = $this->cache_dir . '/xzcache_' . md5($key);  if (is_dir($this->cache_dir) && is_file($cache_file)) {   $timedif = @(time() - filemtime($cache_file));   if ($timedif >= $this->cache_time) {    $result['cached'] = 2;   }else{    // cached file is fresh enough, return cached array    $result['value'] = unserialize(file_get_contents($cache_file));    $result['cached'] = 1;   }  }else {   echo "Error:no cache";   $result['cached'] = 0;  }  return $result; }} //end of class

用法示例如下：

$cache = new XZCache();$key = 'global';$value = $GLOBALS;$cache->saveCache($key, $value);$result = $cache->getCache($key);var_dump($result);

希望本文所述对大家的php程序设计有所帮助。