2 /////////////////////////////////////////////////////////////////
3 /// getID3() by James Heinrich <info@getid3.org> //
4 // available at http://getid3.sourceforge.net //
5 // or http://www.getid3.org //
6 // also https://github.com/JamesHeinrich/getID3 //
7 /////////////////////////////////////////////////////////////////
9 // extension.cache.dbm.php - part of getID3() //
10 // Please see readme.txt for more information //
12 /////////////////////////////////////////////////////////////////
14 // This extension written by Allan Hansen <ahØartemis*dk> //
16 /////////////////////////////////////////////////////////////////
20 * This is a caching extension for getID3(). It works the exact same
21 * way as the getID3 class, but return cached information very fast
25 * Normal getID3 usage (example):
27 * require_once 'getid3/getid3.php';
28 * $getID3 = new getID3;
29 * $getID3->encoding = 'UTF-8';
30 * $info1 = $getID3->analyze('file1.flac');
31 * $info2 = $getID3->analyze('file2.wv');
33 * getID3_cached usage:
35 * require_once 'getid3/getid3.php';
36 * require_once 'getid3/getid3/extension.cache.dbm.php';
37 * $getID3 = new getID3_cached('db3', '/tmp/getid3_cache.dbm',
38 * '/tmp/getid3_cache.lock');
39 * $getID3->encoding = 'UTF-8';
40 * $info1 = $getID3->analyze('file1.flac');
41 * $info2 = $getID3->analyze('file2.wv');
44 * Supported Cache Types
46 * SQL Databases: (use extension.cache.mysql)
48 * cache_type cache_options
49 * -------------------------------------------------------------------
50 * mysql host, database, username, password
53 * DBM-Style Databases: (this extension)
55 * cache_type cache_options
56 * -------------------------------------------------------------------
57 * gdbm dbm_filename, lock_filename
58 * ndbm dbm_filename, lock_filename
59 * db2 dbm_filename, lock_filename
60 * db3 dbm_filename, lock_filename
61 * db4 dbm_filename, lock_filename (PHP5 required)
63 * PHP must have write access to both dbm_filename and lock_filename.
66 * Recommended Cache Types
68 * Infrequent updates, many reads any DBM
69 * Frequent updates mysql
73 class getID3_cached_dbm
extends getID3
76 // public: constructor - see top of this file for cache type and cache_options
77 public function __construct($cache_type, $dbm_filename, $lock_filename) {
79 // Check for dba extension
80 if (!extension_loaded('dba')) {
81 throw new Exception('PHP is not compiled with dba support, required to use DBM style cache.');
84 // Check for specific dba driver
85 if (!function_exists('dba_handlers') ||
!in_array($cache_type, dba_handlers())) {
86 throw new Exception('PHP is not compiled --with '.$cache_type.' support, required to use DBM style cache.');
89 // Create lock file if needed
90 if (!file_exists($lock_filename)) {
91 if (!touch($lock_filename)) {
92 throw new Exception('failed to create lock file: '.$lock_filename);
96 // Open lock file for writing
97 if (!is_writeable($lock_filename)) {
98 throw new Exception('lock file: '.$lock_filename.' is not writable');
100 $this->lock
= fopen($lock_filename, 'w');
102 // Acquire exclusive write lock to lock file
103 flock($this->lock
, LOCK_EX
);
105 // Create dbm-file if needed
106 if (!file_exists($dbm_filename)) {
107 if (!touch($dbm_filename)) {
108 throw new Exception('failed to create dbm file: '.$dbm_filename);
112 // Try to open dbm file for writing
113 $this->dba
= dba_open($dbm_filename, 'w', $cache_type);
116 // Failed - create new dbm file
117 $this->dba
= dba_open($dbm_filename, 'n', $cache_type);
120 throw new Exception('failed to create dbm file: '.$dbm_filename);
123 // Insert getID3 version number
124 dba_insert(getID3
::VERSION
, getID3
::VERSION
, $this->dba
);
128 $this->cache_type
= $cache_type;
129 $this->dbm_filename
= $dbm_filename;
131 // Register destructor
132 register_shutdown_function(array($this, '__destruct'));
134 // Check version number and clear cache if changed
135 if (dba_fetch(getID3
::VERSION
, $this->dba
) != getID3
::VERSION
) {
136 $this->clear_cache();
139 parent
::__construct();
144 // public: destructor
145 public function __destruct() {
148 dba_close($this->dba
);
150 // Release exclusive lock
151 flock($this->lock
, LOCK_UN
);
159 // public: clear cache
160 public function clear_cache() {
163 dba_close($this->dba
);
165 // Create new dbm file
166 $this->dba
= dba_open($this->dbm_filename
, 'n', $this->cache_type
);
169 throw new Exception('failed to clear cache/recreate dbm file: '.$this->dbm_filename
);
172 // Insert getID3 version number
173 dba_insert(getID3
::VERSION
, getID3
::VERSION
, $this->dba
);
175 // Re-register shutdown function
176 register_shutdown_function(array($this, '__destruct'));
181 // public: analyze file
182 public function analyze($filename) {
184 if (file_exists($filename)) {
186 // Calc key filename::mod_time::size - should be unique
187 $key = $filename.'::'.filemtime($filename).'::'.filesize($filename);
190 $result = dba_fetch($key, $this->dba
);
193 if ($result !== false) {
194 return unserialize($result);
199 $result = parent
::analyze($filename);
202 if (file_exists($filename)) {
203 dba_insert($key, serialize($result), $this->dba
);