Definition and function of php file cache class

This article mainly introduces the usage of PHP file cache class. It analyzes the definition, function and specific usage skills of PHP file cache class in detail in the form of examples. It is of great practical value. Friends in need can refer to it

The example in this article describes the usage of php file cache class. The details are as follows:

<?php
/**
 * 简单的文件缓存类
 *
 */
class XZCache{
 // default cache time one hour
 var $cache_time = 3600;
 // default cache dir
 var $cache_dir = &#39;./cache&#39;;
 public function __construct($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 = $this->cache_dir . &#39;/xzcache_&#39; . md5($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, &#39;w&#39;)) {
     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 = $this->cache_dir . &#39;/xzcache_&#39; . md5($key);
  if (is_dir($this->cache_dir) && is_file($cache_file)) {
   $timedif = @(time() - filemtime($cache_file));
   if ($timedif >= $this->cache_time) {
    $result[&#39;cached&#39;] = 2;
   }else{
    // cached file is fresh enough, return cached array
    $result[&#39;value&#39;] = unserialize(file_get_contents($cache_file));
    $result[&#39;cached&#39;] = 1;
   }
  }else {
   echo "Error:no cache";
   $result[&#39;cached&#39;] = 0;
  }
  return $result;
 }
} //end of class

Usage examples are as follows:

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

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