php文件缓存类

1. <?php
   
2. /**
   
3.  * 文件缓存类
   
4.  * @author flynetcn
   
5.  */
   
6. class FileCache
   
7. {
   
8.     const CACHE_DIR = '/tmp/cache';
   
9.     private $dir;
   
10.     private $expire = 300;
    
11. 
    
12.     /**
    
13.      * @param $strDir 缓存子目录(方便清cache)
    
14.      */
    
15.     function __construct($strDir='')
    
16.     {
    
17.         if ($strDir) {
    
18.             $this->dir = self::CACHE_DIR.'/'.$strDir;
    
19.         }
    
20.     }
    
21. 
    
22.     private function getFileName($strKey)
    
23.     {
    
24.         return $this->dir.'/'.$strKey;
    
25.     }
    
26. 
    
27.     public function setExpire($intSecondNum)
    
28.     {
    
29.         if ($intSecondNum<10 || !is_int($intSecondNum)) {
    
30.             return false;
    
31.         }
    
32.         $this->expire = $intSecondNum;
    
33.         return true;
    
34.     }
    
35. 
    
36.     public function getExpire()
    
37.     {
    
38.         return $this->expire;
    
39.     }
    
40. 
    
41.     public function get($strKey)
    
42.     {
    
43.         $strFileName = $this->getFileName($strKey);
    
44.         if (!@file_exists($strFileName)) {
    
45.             return false;
    
46.         }
    
47.         if (filemtime($strFileName) < (time()-$this->expire)) {
    
48.             return false;
    
49.         }
    
50.         $intFileSize = filesize($strFileName);
    
51.         if ($intFileSize == 0) {
    
52.             return false;
    
53.         }
    
54.         if (!$fp = @fopen($strFileName, 'rb')) {
    
55.             return false;
    
56.         }
    
57.         flock($fp, LOCK_SH);
    
58.         $cacheData = unserialize(fread($fp, $intFileSize));
    
59.         flock($fp, LOCK_UN);
    
60.         fclose($fp);
    
61.         return $cacheData;
    
62.     }
    
63. 
    
64.     public function set($strKey, $cacheData)
    
65.     {
    
66.         if (!is_dir($this->dir)) {
    
67.             if (!@mkdir($this->dir, 0755, true)) {
    
68.                 trigger_error("mkdir({$this->dir}, 0755, true) failed", E_USER_ERROR);
    
69.                 return false;
    
70.             }
    
71.         }
    
72.         $strFileName = $this->getFileName($strKey);
    
73.         if (@file_exists($strFileName)) {
    
74.             $intMtime = filemtime($strFileName);
    
75.         } else {
    
76.             $intMtime = 0;
    
77.         }
    
78.         if (!$fp = fopen($strFileName,'wb')) {
    
79.             return false;
    
80.         }
    
81.         if (!flock($fp, LOCK_EX+LOCK_NB)) {
    
82.             fclose($fp);
    
83.             return false;
    
84.         }
    
85.         if (time() - $intMtime < 1) {
    
86.             flock($fp, LOCK_UN);
    
87.             fclose($fp);
    
88.             return false;
    
89.         }
    
90.         fseek($fp, 0);
    
91.         ftruncate($fp, 0);
    
92.         fwrite($fp, serialize($cacheData));
    
93.         flock($fp, LOCK_UN);
    
94.         fclose($fp);
    
95.         @chmod($strFileName, 0755);
    
96.         return true;
    
97.     }
    
98. }