lite.php

来自「视频监控网络部分的协议ddns,的模块的实现代码,请大家大胆指正.」· PHP 代码 · 共 756 行 · 第 1/2 页

    {
        $this->_setFileName($id, $group);
        if ($this->_memoryCaching) {
            if (isset($this->_memoryCachingArray[$this->_file])) {
                unset($this->_memoryCachingArray[$this->_file]);
                $this->_memoryCachingCounter = $this->_memoryCachingCounter - 1;
            }
            if ($this->_onlyMemoryCaching) {
                return true;
            }
        }
        return $this->_unlink($this->_file);
    }

    /**
    * Clean the cache
    *
    * if no group is specified all cache files will be destroyed
    * else only cache files of the specified group will be destroyed
    *
    * @param string $group name of the cache group
    * @param string $mode flush cache mode : 'old', 'ingroup', 'notingroup', 
    *                                        'callback_myFunction'
    * @return boolean true if no problem
    * @access public
    */
    function clean($group = false, $mode = 'ingroup')
    {
        return $this->_cleanDir($this->_cacheDir, $group, $mode);
    }
       
    /**
    * Set to debug mode
    *
    * When an error is found, the script will stop and the message will be displayed
    * (in debug mode only).
    *
    * @access public
    */
    function setToDebug()
    {
        $this->_pearErrorMode = CACHE_LITE_ERROR_DIE;
    }

    /**
    * Set a new life time
    *
    * @param int $newLifeTime new life time (in seconds)
    * @access public
    */
    function setLifeTime($newLifeTime)
    {
        $this->_lifeTime = $newLifeTime;
        $this->_refreshTime = time() - $newLifeTime;
    }

    /**
    * Save the state of the caching memory array into a cache file cache
    *
    * @param string $id cache id
    * @param string $group name of the cache group
    * @access public
    */
    function saveMemoryCachingState($id, $group = 'default')
    {
        if ($this->_caching) {
            $array = array(
                'counter' => $this->_memoryCachingCounter,
                'array' => $this->_memoryCachingState
            );
            $data = serialize($array);
            $this->save($data, $id, $group);
        }
    }

    /**
    * Load the state of the caching memory array from a given cache file cache
    *
    * @param string $id cache id
    * @param string $group name of the cache group
    * @param boolean $doNotTestCacheValidity if set to true, the cache validity won't be tested
    * @access public
    */
    function getMemoryCachingState($id, $group = 'default', $doNotTestCacheValidity = false)
    {
        if ($this->_caching) {
            if ($data = $this->get($id, $group, $doNotTestCacheValidity)) {
                $array = unserialize($data);
                $this->_memoryCachingCounter = $array['counter'];
                $this->_memoryCachingArray = $array['array'];
            }
        }
    }
    
    /**
    * Return the cache last modification time
    *
    * BE CAREFUL : THIS METHOD IS FOR HACKING ONLY !
    *
    * @return int last modification time
    */
    function lastModified() {
        return @filemtime($this->_file);
    }
    
    /**
    * Trigger a PEAR error
    *
    * To improve performances, the PEAR.php file is included dynamically.
    * The file is so included only when an error is triggered. So, in most
    * cases, the file isn't included and perfs are much better.
    *
    * @param string $msg error message
    * @param int $code error code
    * @access public
    */
    function raiseError($msg, $code)
    {
        include_once('PEAR.php');
        PEAR::raiseError($msg, $code, $this->_pearErrorMode);
    }
    
    // --- Private methods ---

    /**
    * Remove a file
    * 
    * @param string $file complete file path and name
    * @return boolean true if no problem
    * @access private
    */
    function _unlink($file)
    {
        if (!@unlink($file)) {
            $this->raiseError('Cache_Lite : Unable to remove cache !', -3);
            return false;
        } else {
            return true;
        }
    }

    /**
    * Recursive function for cleaning cache file in the given directory
    *
    * @param string $dir directory complete path (with a trailing slash)
    * @param string $group name of the cache group
    * @param string $mode flush cache mode : 'old', 'ingroup', 'notingroup',
                                             'callback_myFunction'
    * @return boolean true if no problem
    * @access private
    */
    function _cleanDir($dir, $group = false, $mode = 'ingroup')     
    {
        if ($this->_fileNameProtection) {
            $motif = ($group) ? 'cache_'.md5($group).'_' : 'cache_';
        } else {
            $motif = ($group) ? 'cache_'.$group.'_' : 'cache_';
        }
        if ($this->_memoryCaching) {
            while (list($key, $value) = each($this->_memoryCachingArray)) {
                if (strpos($key, $motif, 0)) {
                    unset($this->_memoryCachingArray[$key]);
                    $this->_memoryCachingCounter = $this->_memoryCachingCounter - 1;
                }
            }
            if ($this->_onlyMemoryCaching) {
                return true;
            }
        }
        if (!($dh = opendir($dir))) {
            $this->raiseError('Cache_Lite : Unable to open cache directory !', -4);
            return false;
        }
        $result = true;
        while ($file = readdir($dh)) {
            if (($file != '.') && ($file != '..')) {
                if (substr($file, 0, 6)=='cache_') {
                    $file2 = $dir . $file;
                    if (is_file($file2)) {
                        switch (substr($mode, 0, 9)) {
                            case 'old':
                                // files older than lifeTime get deleted from cache
                                if ((mktime() - filemtime($file2)) > $this->_lifeTime) {
                                    $result = ($result and ($this->_unlink($file2)));
                                }
                                break;
                            case 'notingrou':
                                if (!strpos($file2, $motif, 0)) {
                                    $result = ($result and ($this->_unlink($file2)));
                                }
                                break;
                            case 'callback_':
                                $func = substr($mode, 9, strlen($mode) - 9);
                                if ($func($file2, $group)) {
                                    $result = ($result and ($this->_unlink($file2)));
                                }
                                break;
                            case 'ingroup':
                            default:
                                if (strpos($file2, $motif, 0)) {
                                    $result = ($result and ($this->_unlink($file2)));
                                }
                                break;
                        }
                    }
                    if ((is_dir($file2)) and ($this->_hashedDirectoryLevel>0)) {
                        $result = ($result and ($this->_cleanDir($file2 . '/', $group, $mode)));
                    }
                }
            }
        }
        return $result;
    }
      
    /**
    * Add some date in the memory caching array
    *
    * @param string $id cache id
    * @param string $data data to cache
    * @access private
    */
    function _memoryCacheAdd($id, $data)
    {
        $this->_memoryCachingArray[$this->_file] = $data;
        if ($this->_memoryCachingCounter >= $this->_memoryCachingLimit) {
            list($key, $value) = each($this->_memoryCachingArray);
            unset($this->_memoryCachingArray[$key]);
        } else {
            $this->_memoryCachingCounter = $this->_memoryCachingCounter + 1;
        }
    }

    /**
    * Make a file name (with path)
    *
    * @param string $id cache id
    * @param string $group name of the group
    * @access private
    */
    function _setFileName($id, $group)
    {
        
        if ($this->_fileNameProtection) {
            $suffix = 'cache_'.md5($group).'_'.md5($id);
        } else {
            $suffix = 'cache_'.$group.'_'.$id;
        }
        $root = $this->_cacheDir;
        if ($this->_hashedDirectoryLevel>0) {
            $hash = md5($suffix);
            for ($i=0 ; $i<$this->_hashedDirectoryLevel ; $i++) {
                $root = $root . 'cache_' . substr($hash, 0, $i + 1) . '/';
            }   
        }
        $this->_fileName = $suffix;
        $this->_file = $root.$suffix;
    }
    
    /**
    * Read the cache file and return the content
    *
    * @return string content of the cache file
    * @access private
    */
    function _read()
    {
        $fp = @fopen($this->_file, "rb");
        if ($this->_fileLocking) @flock($fp, LOCK_SH);
        if ($fp) {
            clearstatcache(); // because the filesize can be cached by PHP itself...
            $length = @filesize($this->_file);
            $mqr = get_magic_quotes_runtime();
            set_magic_quotes_runtime(0);
            if ($this->_readControl) {
                $hashControl = @fread($fp, 32);
                $length = $length - 32;
            } 
            if ($length) {
                $data = @fread($fp, $length);
            } else {
                $data = '';
            }
            set_magic_quotes_runtime($mqr);
            if ($this->_fileLocking) @flock($fp, LOCK_UN);
            @fclose($fp);
            if ($this->_readControl) {
                $hashData = $this->_hash($data, $this->_readControlType);
                if ($hashData != $hashControl) {
                    @touch($this->_file, time() - 2*abs($this->_lifeTime)); 
                    return false;
                }
            }
            return $data;
        }
        $this->raiseError('Cache_Lite : Unable to read cache !', -2);   
        return false;
    }
    
    /**
    * Write the given data in the cache file
    *
    * @param string $data data to put in cache
    * @return boolean true if ok
    * @access private
    */
    function _write($data)
    {
        $try = 1;
        while ($try<=2) {
            $fp = @fopen($this->_file, "wb");
            if ($fp) {
                if ($this->_fileLocking) @flock($fp, LOCK_EX);
                if ($this->_readControl) {
                    @fwrite($fp, $this->_hash($data, $this->_readControlType), 32);
                }
                $len = strlen($data);
                @fwrite($fp, $data, $len);
                if ($this->_fileLocking) @flock($fp, LOCK_UN);
                @fclose($fp);
                return true;
            } else {
                if (($try==1) and ($this->_hashedDirectoryLevel>0)) {
                    $hash = md5($this->_fileName);
                    $root = $this->_cacheDir;
                    for ($i=0 ; $i<$this->_hashedDirectoryLevel ; $i++) {
                        $root = $root . 'cache_' . substr($hash, 0, $i + 1) . '/';
                        @mkdir($root, $this->_hashedDirectoryUmask);
                    }
                    $try = 2;
                } else {
                    $try = 999;
                }
            }
        }
        $this->raiseError('Cache_Lite : Unable to write cache file : '.$this->_file, -1);
        return false;
    }
    
    /**
    * Write the given data in the cache file and control it just after to avoir corrupted cache entries
    *
    * @param string $data data to put in cache
    * @return boolean true if the test is ok
    * @access private
    */
    function _writeAndControl($data)
    {
        $this->_write($data);
        $dataRead = $this->_read($data);
        return ($dataRead==$data);
    }
    
    /**
    * Make a control key with the string containing datas
    *
    * @param string $data data
    * @param string $controlType type of control 'md5', 'crc32' or 'strlen'
    * @return string control key
    * @access private
    */
    function _hash($data, $controlType)
    {
        switch ($controlType) {
        case 'md5':
            return md5($data);
        case 'crc32':
            return sprintf('% 32d', crc32($data));
        case 'strlen':
            return sprintf('% 32d', strlen($data));
        default:
            $this->raiseError('Unknown controlType ! (available values are only \'md5\', \'crc32\', \'strlen\')', -5);
        }
    }
    
} 

?>