Cache revisited #1 #2

git-svn-id: svn+ssh://code.netmonsters.ru/svn/majestic/trunk@93 4cb57b5f-5bbd-dd11-951b-001d605cbbc5

classes/Cache.class.php

@@ -14,22 +14,61 @@
 final class Cache
 {
     private $cache_file;
+    private $cache_folder;
     private $cache_time;
 
+    private $mode = 0777;
+    private $infofile = '_infofile';
+
+    const HASH_ENABLE = true;
+
     function __construct($cache_name, $cache_time)
     {
+        if (!preg_match('/[a-zA-Z0-9_]/', $cache_name)) {
+            throw new MJException('Wrong cache identifier "'.$cache_name.'". Must use only [a-zA-Z0-9_]');
+        }
+
+        if ($cache_name == $this->infofile) {
+            throw new MJException('Name "'.$this->infofile.'" is reserved. Try another one.');
+        }
+
+        if ($cache_time == 0) {
+            throw new MJException('cache_time must be non-zero');
+        }
+
+        if ($cache_time > 86400) {
+            throw new MJException('cache_time cannot be greater than 86400 sec (24 hours)');
+        }
+
+        if (substr($cache_name, 0, 1) == '_') {
+            $this->cache_folder = CACHE_PATH;
+        } else {
+            $parts = explode('_', $cache_name, 2);
+            $this->cache_folder = CACHE_PATH.'/'.(isset($parts[1]) ? $parts[0] : '_all');
+            if (self::HASH_ENABLE) {
+                $hash = md5($cache_name);
+                $this->cache_folder .= '/'.substr($hash, 0, 1).'/'.substr($hash, 0, 2);
+            }
+        }
+
+        $this->cache_file = $this->cache_folder.'/'.$cache_name;
+        if (!is_writable($this->cache_folder)) {
+            mkdir($this->cache_folder, $this->mode, true);
+        }
+
         $this->cache_time = (int) $cache_time;
-        $this->cache_file = CACHE_PATH.'/'.$cache_name;
     }
 
     /**
      * Сохраняет кэш в файл
      *
+     * @param string/array $data - строка (либо одномерный массив) сохраняемых данных
      * @return boolean - сохранил или нет
      */
     function save($data)
     {
-        if ($this->cache_time != 0) {
+        if ($this->cache_time != 0 && is_writable($this->cache_folder)) {
+            $this->clearOld(); //очистка старых файлов.
             return (bool) file_put_contents($this->cache_file, $data);
         }
         return false;
@@ -42,9 +81,16 @@ final class Cache
      */
     function load()
     {
-        return file_get_contents($this->cache_file);
+        if ($this->cache_time != 0) {
+            return file_get_contents($this->cache_file);
+        }
+        return false;
     }
 
+    /**
+    * Принудительно очистить кеш
+    *
+    */
     function reset()
     {
         @unlink($this->cache_file);
@@ -57,13 +103,26 @@ final class Cache
     */
     function isCached()
     {
-        if (! file_exists($this->cache_file)) {
-            return false;
+        if (is_readable($this->cache_file)) {
+            if ($this->cache_time < 0 || $this->cache_time + filemtime($this->cache_file) > time()) {
+                return true;
+            }
+            $this->reset(); //удалим просроченый файл
         }
-        if ($this->cache_time > 0 && $this->cache_time + filemtime($this->cache_file) < TIME_NOW) {
-            return false;
+        return false;
+    }
+
+    /**
+    * Удаление файлов старше суток
+    *
+    */
+    function clearOld()
+    {
+        $file = CACHE_PATH.'/'.$this->infofile;
+        if (!file_exists($file) || date('Ymd', filemtime($file)) != date('Ymd')) {
+            exec('find '.CACHE_PATH.'/ -mtime +1 -delete'); //не удаляет папки сохраняя структуру
+            touch($file);
         }
-        return true;
     }
 }