--- /dev/null
+<?php
+/////////////////////////////////////////////////////////////////
+/// getID3() by James Heinrich <info@getid3.org> //
+// available at http://getid3.sourceforge.net //
+// or http://www.getid3.org //
+// also https://github.com/JamesHeinrich/getID3 //
+/////////////////////////////////////////////////////////////////
+// //
+// extension.cache.dbm.php - part of getID3() //
+// Please see readme.txt for more information //
+// ///
+/////////////////////////////////////////////////////////////////
+// //
+// This extension written by Allan Hansen <ahØartemis*dk> //
+// ///
+/////////////////////////////////////////////////////////////////
+
+
+/**
+* This is a caching extension for getID3(). It works the exact same
+* way as the getID3 class, but return cached information very fast
+*
+* Example:
+*
+* Normal getID3 usage (example):
+*
+* require_once 'getid3/getid3.php';
+* $getID3 = new getID3;
+* $getID3->encoding = 'UTF-8';
+* $info1 = $getID3->analyze('file1.flac');
+* $info2 = $getID3->analyze('file2.wv');
+*
+* getID3_cached usage:
+*
+* require_once 'getid3/getid3.php';
+* require_once 'getid3/getid3/extension.cache.dbm.php';
+* $getID3 = new getID3_cached('db3', '/tmp/getid3_cache.dbm',
+* '/tmp/getid3_cache.lock');
+* $getID3->encoding = 'UTF-8';
+* $info1 = $getID3->analyze('file1.flac');
+* $info2 = $getID3->analyze('file2.wv');
+*
+*
+* Supported Cache Types
+*
+* SQL Databases: (use extension.cache.mysql)
+*
+* cache_type cache_options
+* -------------------------------------------------------------------
+* mysql host, database, username, password
+*
+*
+* DBM-Style Databases: (this extension)
+*
+* cache_type cache_options
+* -------------------------------------------------------------------
+* gdbm dbm_filename, lock_filename
+* ndbm dbm_filename, lock_filename
+* db2 dbm_filename, lock_filename
+* db3 dbm_filename, lock_filename
+* db4 dbm_filename, lock_filename (PHP5 required)
+*
+* PHP must have write access to both dbm_filename and lock_filename.
+*
+*
+* Recommended Cache Types
+*
+* Infrequent updates, many reads any DBM
+* Frequent updates mysql
+*/
+
+
+class getID3_cached_dbm extends getID3
+{
+
+ // public: constructor - see top of this file for cache type and cache_options
+ public function __construct($cache_type, $dbm_filename, $lock_filename) {
+
+ // Check for dba extension
+ if (!extension_loaded('dba')) {
+ throw new Exception('PHP is not compiled with dba support, required to use DBM style cache.');
+ }
+
+ // Check for specific dba driver
+ if (!function_exists('dba_handlers') || !in_array($cache_type, dba_handlers())) {
+ throw new 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($lock_filename)) {
+ throw new Exception('failed to create lock file: '.$lock_filename);
+ }
+ }
+
+ // Open lock file for writing
+ if (!is_writeable($lock_filename)) {
+ throw new Exception('lock file: '.$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($dbm_filename)) {
+ throw new Exception('failed to create dbm file: '.$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) {
+ throw new Exception('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) {
+ $this->clear_cache();
+ }
+
+ parent::__construct();
+ }
+
+
+
+ // public: destructor
+ public function __destruct() {
+
+ // Close dbm file
+ dba_close($this->dba);
+
+ // Release exclusive lock
+ flock($this->lock, LOCK_UN);
+
+ // Close lock file
+ fclose($this->lock);
+ }
+
+
+
+ // public: clear cache
+ 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) {
+ throw new Exception('failed to clear cache/recreate dbm file: '.$this->dbm_filename);
+ }
+
+ // Insert getID3 version number
+ dba_insert(getID3::VERSION, getID3::VERSION, $this->dba);
+
+ // Re-register shutdown function
+ register_shutdown_function(array($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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