diff options
Diffstat (limited to 'kohana/libraries/drivers/Cache/File.php')
| -rw-r--r-- | kohana/libraries/drivers/Cache/File.php | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/kohana/libraries/drivers/Cache/File.php b/kohana/libraries/drivers/Cache/File.php new file mode 100644 index 00000000..01d6c383 --- /dev/null +++ b/kohana/libraries/drivers/Cache/File.php @@ -0,0 +1,245 @@ +<?php defined('SYSPATH') or die('No direct script access.'); +/** + * File-based Cache driver. + * + * $Id$ + * + * @package Cache + * @author Kohana Team + * @copyright (c) 2007-2008 Kohana Team + * @license http://kohanaphp.com/license.html + */ +class Cache_File_Driver implements Cache_Driver { + + protected $directory = ''; + + /** + * Tests that the storage location is a directory and is writable. + */ + public function __construct($directory) + { + // Find the real path to the directory + $directory = str_replace('\\', '/', realpath($directory)).'/'; + + // Make sure the cache directory is writable + if ( ! is_dir($directory) OR ! is_writable($directory)) + throw new Kohana_Exception('cache.unwritable', $directory); + + // Directory is valid + $this->directory = $directory; + } + + /** + * Finds an array of files matching the given id or tag. + * + * @param string cache id or tag + * @param bool search for tags + * @return array of filenames matching the id or tag + * @return void if no matching files are found + */ + public function exists($id, $tag = FALSE) + { + if ($id === TRUE) + { + // Find all the files + $files = glob($this->directory.'*~*~*'); + } + elseif ($tag == TRUE) + { + // Find all the files that have the tag name + $files = glob($this->directory.'*~*'.$id.'*~*'); + + // Find all tags matching the given tag + foreach ($files as $i => $file) + { + // Split the files + $tags = explode('~', $file); + + // Find valid tags + if (count($tags) !== 3 OR empty($tags[1])) + continue; + + // Split the tags by plus signs, used to separate tags + $tags = explode('+', $tags[1]); + + if ( ! in_array($tag, $tags)) + { + // This entry does not match the tag + unset($files[$i]); + } + } + } + else + { + // Find all the files matching the given id + $files = glob($this->directory.$id.'~*'); + } + + return empty($files) ? NULL : $files; + } + + /** + * Sets a cache item to the given data, tags, and lifetime. + * + * @param string cache id to set + * @param string data in the cache + * @param array cache tags + * @param integer lifetime + * @return bool + */ + public function set($id, $data, $tags, $lifetime) + { + // Remove old cache files + $this->delete($id); + + // Cache File driver expects unix timestamp + if ($lifetime !== 0) + { + $lifetime += time(); + } + + // Construct the filename + $filename = $id.'~'.implode('+', $tags).'~'.$lifetime; + + // Write the file, appending the sha1 signature to the beginning of the data + return (bool) file_put_contents($this->directory.$filename, sha1($data).$data); + } + + /** + * Finds an array of ids for a given tag. + * + * @param string tag name + * @return array of ids that match the tag + */ + public function find($tag) + { + if ($files = $this->exists($tag, TRUE)) + { + // Length of directory name + $offset = strlen($this->directory); + + // Find all the files with the given tag + $array = array(); + foreach ($files as $file) + { + // Get the id from the filename + $array[] = substr(current(explode('~', $file)), $offset); + } + + return $array; + } + + return FALSE; + } + + /** + * Fetches a cache item. This will delete the item if it is expired or if + * the hash does not match the stored hash. + * + * @param string cache id + * @return mixed|NULL + */ + public function get($id) + { + if ($file = $this->exists($id)) + { + // Always process the first result + $file = current($file); + + // Validate that the cache has not expired + if ($this->expired($file)) + { + // Remove this cache, it has expired + $this->delete($id); + } + else + { + $data = file_get_contents($file); + + // Find the hash of the data + $hash = substr($data, 0, 40); + + // Remove the hash from the data + $data = substr($data, 40); + + if ($hash !== sha1($data)) + { + // Remove this cache, it doesn't validate + $this->delete($id); + + // Unset data to prevent it from being returned + unset($data); + } + } + } + + // Return NULL if there is no data + return isset($data) ? $data : NULL; + } + + /** + * Deletes a cache item by id or tag + * + * @param string cache id or tag, or TRUE for "all items" + * @param boolean use tags + * @return boolean + */ + public function delete($id, $tag = FALSE) + { + $files = $this->exists($id, $tag); + + if (empty($files)) + return FALSE; + + // Disable all error reporting while deleting + $ER = error_reporting(0); + + foreach ($files as $file) + { + // Remove the cache file + if ( ! unlink($file)) + Kohana::log('error', 'Cache: Unable to delete cache file: '.$file); + } + + // Turn on error reporting again + error_reporting($ER); + + return TRUE; + } + + /** + * Deletes all cache files that are older than the current time. + * + * @return void + */ + public function delete_expired() + { + if ($files = $this->exists(TRUE)) + { + foreach ($files as $file) + { + if ($this->expired($file)) + { + // The cache file has already expired, delete it + @unlink($file) or Kohana::log('error', 'Cache: Unable to delete cache file: '.$file); + } + } + } + } + + /** + * Check if a cache file has expired by filename. + * + * @param string filename + * @return bool + */ + protected function expired($file) + { + // Get the expiration time + $expires = (int) substr($file, strrpos($file, '~') + 1); + + // Expirations of 0 are "never expire" + return ($expires !== 0 AND $expires <= time()); + } + +} // End Cache File Driver
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