php的頁面緩存練習

  1 <?php
  2 /*
  3  * 自定義頁面緩存類
  4  */
  5 namespace page_cache;
  6 class Page
  7 {
  8     public $CacheRoot = "pageCache/";//緩存文件存放目錄,
  9     public $CacheLimitTime = 0;//緩存文件更新時間，0不更新
 10     public $CacheFileName = '';//緩存文件名，
 11     public $CacheFileExt = '.php';//緩存文件擴展名稱
 12 
 13     //構造函數,設置緩存更新時間
 14     public function __construct($CacheLimitTime)
 15     {
 16         if(intval($CacheLimitTime))
 17         {
 18             $this->CacheLimitTime = $CacheLimitTime;
 19             $this->CacheFileName = $this->GetFileName();
 20             ob_start();
 21             return true;
 22         }
 23         else
 24         {
 25             return false;
 26         }
 27     }
 28 
 29 
 30     //檢查緩存文件是否在更新時間內，在更新時間內返回文件內容，不在更新時間內返回false
 31     public function CheckTime()
 32     {
 33         if(file_exists($this->CacheFileName))
 34         {
 35             if($this->CacheLimitTime +$this->GetFileCreateTime($this->CacheFileName)> time())
 36             {
 37                 echo file_get_contents($this->CacheFileName);
 38                 ob_end_flush();//輸出內容到緩衝區
 39                 exit();
 40             }
 41         }
 42         return false;
 43     }
 44 
 45     /*
 46      * 建立緩存文件
 47      * param $cacheFileName; type string; value 自定義緩存文件的名稱
 48      */
 49     public function CreateCacheFile($cacheFileName='')
 50     {
 51         $getCacheContent = ob_get_contents();
 52         ob_end_flush ();
 53         if(!empty($cacheFileName))
 54         {
 55            return  $this->SaveFile($cacheFileName,$getCacheContent);
 56         }
 57         else
 58         {
 59             return $this->SaveFile($this->CacheFileName,$getCacheContent);
 60         }
 61     }
 62 
 63     /*
 64      * 清除緩存
 65      * param $fileName;type string;value all;note:value is all,clear all cache;
 66      */
 67     public function ClearCache($fileName = "all")
 68     {
 69         if($fileName!='all')
 70         {
 71             $fileName = $this->CacheRoot.strtoupper(md5($fileName)).$this->CacheFileExt;
 72             if(file_exists($fileName))
 73             {
 74                 return @unlink($fileName);
 75             }
 76             else
 77             {
 78                 return false;
 79             }
 80         }
 81         if($fileName = 'all')
 82         {
 83             if(is_dir(($this->CacheRoot)))
 84             {
 85                if($dir = opendir($this->CacheRoot))
 86                {
 87                    while($file = readdir($dir))
 88                    {
 89                        if(!is_dir($file))
 90                        {
 91                            unlink($this->CacheRoot.$file);
 92                        }
 93 
 94                    }
 95                    closedir($dir);
 96                    return true;
 97                }
 98             }
 99             else
100             {
101                 return false;
102             }
103         }
104     }
105     //獲取緩存的文件名稱
106     public function GetFileName()
107     {
108         return $this->CacheRoot.strtoupper(md5($_SERVER['REQUEST_URI'])).$this->CacheFileExt;
109     }
110 
111     //返回緩存文件上次修改的時間
112     public function GetFileCreateTime($filename)
113     {
114         if(!trim($filename)) return 0;
115         if(file_exists($filename))
116         {
117             return intval(filemtime($filename));
118         }
119         else
120         {
121             return 0;
122         }
123     }
124 
125     //保存文件並寫入內容
126     public function SaveFile($filename,$text)
127     {
128         if(empty($filename)||empty($text))
129         {
130             return false;
131         }
132         if($this->CacheDir(dirname($filename)))
133         {
134             if($fp = fopen($filename,"w"))
135             {
136                 if(fwrite($fp,$text))
137                 {
138                     fclose($fp);
139                     return true;
140                 }
141                 else
142                 {
143                     fclose($fp);
144                     return false;
145                 }
146             }
147         }
148 
149     }
150 
151 
152     //建立緩存目錄
153     public function CacheDir($dir,$mode="0777")
154     {
155         if(empty($dir))
156         {
157             return false;
158         }
159         $dir = str_replace("\\","/",$dir);
160 
161         $dir = explode("/",$dir);
162 
163         $mkdir = '';
164         foreach($dir as $val)
165         {
166             $mkdir .= $val.'/';
167             if($val=='./'||$val=='../'||$val=="")
168             {
169                 continue;
170             }
171             if(!file_exists($mkdir))
172             {
173                 if(!@mkdir($mkdir,$mode))
174                 {
175                     return false;
176                 }
177             }
178         }
179 
180         return true;
181 
182     }
183 
184 }
185 
186 
187 $cache = new Page(30);
188 $cache->CheckTime();
189 echo "Now is : " . date ( "Y-m-d H:i:s" ,time());
190 $cache ->CreateCacheFile();