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Revision Autor Zeilennr. Zeile
1 lars 1 
<?php
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/**
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 * Container for all file-based cache methods. Inherits additional methods from <CacheCore>. Adheres
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 * to the ICacheCore interface.
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 *
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 * @version 2012.01.28
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 * @copyright 2006-2012 Ryan Parman
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 * @copyright 2006-2010 Foleeo, Inc.
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 * @copyright 2012 Amazon.com, Inc. or its affiliates.
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 * @copyright 2008-2010 Contributors
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 * @license http://opensource.org/licenses/bsd-license.php Simplified BSD License
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 * @link http://github.com/skyzyx/cachecore CacheCore
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 * @link http://getcloudfusion.com CloudFusion
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 */
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class CacheFile extends CacheCore implements ICacheCore
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{
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	/*%******************************************************************************************%*/
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	// CONSTRUCTOR
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	/**
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	 * Constructs a new instance of this class.
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	 *
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	 * @param string $name (Required) A name to uniquely identify the cache object.
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	 * @param string $location (Required) The location to store the cache object in. This may vary by cache method.
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	 * @param integer $expires (Required) The number of seconds until a cache object is considered stale.
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	 * @param boolean $gzip (Optional) Whether data should be gzipped before being stored. Defaults to true.
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	 * @return object Reference to the cache object.
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	 */
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	public function __construct($name, $location, $expires, $gzip = true)
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	{
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		parent::__construct($name, $location, $expires, $gzip);
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		$this->id = $this->location . '/' . $this->name . '.cache';
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	}
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	/**
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	 * Creates a new cache.
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	 *
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	 * @param mixed $data (Required) The data to cache.
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	 * @return boolean Whether the operation was successful.
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	 */
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	public function create($data)
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	{
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		if (file_exists($this->id))
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		{
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			return false;
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		}
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		elseif (realpath($this->location) && file_exists($this->location) && is_writeable($this->location))
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		{
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			$data = serialize($data);
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			$data = $this->gzip ? gzcompress($data) : $data;
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			return (bool) file_put_contents($this->id, $data);
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		}
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		elseif (realpath($this->location) && file_exists($this->location))
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		{
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			throw new CacheFile_Exception('The file system location "' . $this->location . '" is not writable. Check the file system permissions for this directory.');
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		}
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		else
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		{
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			throw new CacheFile_Exception('The file system location "' . $this->location . '" does not exist. Create the directory, or double-check any relative paths that may have been set.');
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		}
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		return false;
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	}
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	/**
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	 * Reads a cache.
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	 *
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	 * @return mixed Either the content of the cache object, or boolean `false`.
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	 */
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	public function read()
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	{
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		if (file_exists($this->id) && is_readable($this->id))
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		{
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			$data = file_get_contents($this->id);
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			$data = $this->gzip ? gzuncompress($data) : $data;
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			$data = unserialize($data);
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			if ($data === false)
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			{
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				/*
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					This should only happen when someone changes the gzip settings and there is
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					existing data or someone has been mucking about in the cache folder manually.
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					Delete the bad entry since the file cache doesn't clean up after itself and
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					then return false so fresh data will be retrieved.
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				 */
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				$this->delete();
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				return false;
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			}
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			return $data;
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		}
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		return false;
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	}
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	/**
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	 * Updates an existing cache.
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	 *
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	 * @param mixed $data (Required) The data to cache.
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	 * @return boolean Whether the operation was successful.
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	 */
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	public function update($data)
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	{
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		if (file_exists($this->id) && is_writeable($this->id))
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		{
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			$data = serialize($data);
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			$data = $this->gzip ? gzcompress($data) : $data;
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			return (bool) file_put_contents($this->id, $data);
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		}
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		else
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		{
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			throw new CacheFile_Exception('The file system location is not writeable. Check your file system permissions and ensure that the cache directory exists.');
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		}
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		return false;
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	}
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	/**
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	 * Deletes a cache.
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	 *
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	 * @return boolean Whether the operation was successful.
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	 */
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	public function delete()
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	{
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		if (file_exists($this->id))
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		{
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			return unlink($this->id);
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		}
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		return false;
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	}
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	/**
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	 * Checks whether the cache object is expired or not.
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	 *
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	 * @return boolean Whether the cache is expired or not.
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	 */
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	public function is_expired()
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	{
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		if ($this->timestamp() + $this->expires < time())
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		{
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			return true;
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		}
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		return false;
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	}
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	/**
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	 * Retrieves the timestamp of the cache.
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	 *
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	 * @return mixed Either the Unix time stamp of the cache creation, or boolean `false`.
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	 */
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	public function timestamp()
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	{
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		clearstatcache();
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		if (file_exists($this->id))
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		{
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			$this->timestamp = filemtime($this->id);
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			return $this->timestamp;
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		}
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		return false;
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	}
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	/**
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	 * Resets the freshness of the cache.
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	 *
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	 * @return boolean Whether the operation was successful.
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	 */
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	public function reset()
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	{
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		if (file_exists($this->id))
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		{
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			return touch($this->id);
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		}
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		return false;
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	}
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}
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/*%******************************************************************************************%*/
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// EXCEPTIONS
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class CacheFile_Exception extends CacheCore_Exception {}