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Diffstat (limited to 'modules/getid3/extension.cache.dbm.php')
| -rw-r--r-- | modules/getid3/extension.cache.dbm.php | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/modules/getid3/extension.cache.dbm.php b/modules/getid3/extension.cache.dbm.php new file mode 100644 index 00000000..4c70b3eb --- /dev/null +++ b/modules/getid3/extension.cache.dbm.php @@ -0,0 +1,217 @@ +<?php +// +----------------------------------------------------------------------+
+// | PHP version 5 |
+// +----------------------------------------------------------------------+
+// | Copyright (c) 2002-2006 James Heinrich, Allan Hansen |
+// +----------------------------------------------------------------------+
+// | This source file is subject to version 2 of the GPL license, |
+// | that is bundled with this package in the file license.txt and is |
+// | available through the world-wide-web at the following url: |
+// | http://www.gnu.org/copyleft/gpl.html | +// +----------------------------------------------------------------------+ +// | getID3() - http://getid3.sourceforge.net or http://www.getid3.org | +// +----------------------------------------------------------------------+
+// | Authors: James Heinrich <infoØgetid3*org> |
+// | Allan Hansen <ahØartemis*dk> |
+// +----------------------------------------------------------------------+ +// | extension.cache.mysql.php | +// | MySQL Cache Extension. | +// | dependencies: getid3. | +// +----------------------------------------------------------------------+
+//
+// $Id: extension.cache.dbm.php,v 1.2 2006/11/02 10:47:59 ah Exp $ + + +/** +* This is a caching extension for getID3(). It works the exact same +* way as the getID3 class, but return cached information very fast +* +* Example: (see also demo.cache.dbm.php in /demo/) +* +* Normal getID3 usage (example): +* +* require_once 'getid3/getid3.php'; +* $getid3 = new getid3; +* $getid3->encoding = 'UTF-8'; +* try { +* $info1 = $getid3->Analyse('file1.flac'); +* $info2 = $getid3->Analyse('file2.wv'); +* .... +* +* getID3_cached usage: +* +* require_once 'getid3/getid3.php'; +* require_once 'getid3/getid3/extension.cache.mysql.php'; +* $getid3 = new getid3_cached_mysql('localhost', 'database', 'username', 'password'); +* $getid3->encoding = 'UTF-8'; +* try { +* $info1 = $getid3->analyse('file1.flac'); +* $info2 = $getid3->analyse('file2.wv'); +* ... +* +* +* Supported Cache Types +* +* SQL Databases: (use extension.cache.mysql) +* +* cache_type cache_options +* ------------------------------------------------------------------- +* mysql host, database, username, password +* +* +* DBM-Style Databases: (this extension) +* +* cache_type cache_options +* ------------------------------------------------------------------- +* gdbm dbm_filename, lock_filename +* ndbm dbm_filename, lock_filename +* db2 dbm_filename, lock_filename +* db3 dbm_filename, lock_filename +* db4 dbm_filename, lock_filename (PHP5 required) +* +* PHP must have write access to both dbm_filename and lock_filename. +* +* +* Recommended Cache Types +* +* Infrequent updates, many reads any DBM +* Frequent updates mysql +*/ + + +class getid3_cached_dbm extends getid3 +{ + + public function __construct($cache_type, $dbm_filename, $lock_filename) { + + // Check for dba extension + if (!extension_loaded('dba')) { + throw new getid3_exception('PHP is not compiled with dba support, required to use DBM style cache.'); + } + + if (!in_array($cache_type, dba_handlers())) { + throw new getid3_exception('PHP is not compiled --with '.$cache_type.' support, required to use DBM style cache.'); + } + + // Create lock file if needed + if (!file_exists($lock_filename)) { + if (!touch($lock_filename)) { + die('failed to create lock file: ' . $lock_filename); + } + } + + // Open lock file for writing + if (!is_writeable($lock_filename)) { + die('lock file: ' . $lock_filename . ' is not writable'); + } + $this->lock = fopen($lock_filename, 'w'); + + // Acquire exclusive write lock to lock file + flock($this->lock, LOCK_EX); + + // Create dbm-file if needed + if (!file_exists($dbm_filename)) { + if (!touch($dbm_filename)) { + die('failed to create dbm file: ' . $dbm_filename); + } + } + + // Try to open dbm file for writing + $this->dba = @dba_open($dbm_filename, 'w', $cache_type); + if (!$this->dba) { + + // Failed - create new dbm file + $this->dba = dba_open($dbm_filename, 'n', $cache_type); + + if (!$this->dba) { + die('failed to create dbm file: ' . $dbm_filename); + } + + // Insert getID3 version number + dba_insert(getid3::VERSION, getid3::VERSION, $this->dba); + } + + // Init misc values + $this->cache_type = $cache_type; + $this->dbm_filename = $dbm_filename; + + // Register destructor + register_shutdown_function(array($this, '__destruct')); + + // Check version number and clear cache if changed + if (dba_fetch(getid3::VERSION, $this->dba) != getid3::VERSION) { + $this->clear_cache(); + } + + parent::__construct(); + } + + + + public function __destruct() { + + // Close dbm file + @dba_close($this->dba); + + // Release exclusive lock + @flock($this->lock, LOCK_UN); + + // Close lock file + @fclose($this->lock); + } + + + + public function clear_cache() { + + // Close dbm file + dba_close($this->dba); + + // Create new dbm file + $this->dba = dba_open($this->dbm_filename, 'n', $this->cache_type); + + if (!$this->dba) { + die('failed to clear cache/recreate dbm file: ' . $this->dbm_filename); + } + + // Insert getID3 version number + dba_insert(getid3::VERSION, getid3::VERSION, $this->dba); + + // Reregister shutdown function + register_shutdown_function(array($this, '__destruct')); + } + + + + // public: analyze file + public function Analyze($filename) { + + if (file_exists($filename)) { + + // Calc key filename::mod_time::size - should be unique + $key = $filename . '::' . filemtime($filename) . '::' . filesize($filename); + + // Loopup key + $result = dba_fetch($key, $this->dba); + + // Hit + if ($result !== false) { + return unserialize($result); + } + } + + // Miss + $result = parent::Analyze($filename); + + // Save result + if (file_exists($filename)) { + dba_insert($key, serialize($result), $this->dba); + } + + return $result; + } + +} + + +?>
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