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Diffstat (limited to 'getid3/extension.cache.dbm.php')
| -rw-r--r-- | getid3/extension.cache.dbm.php | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/getid3/extension.cache.dbm.php b/getid3/extension.cache.dbm.php new file mode 100644 index 0000000..051bb1f --- /dev/null +++ b/getid3/extension.cache.dbm.php @@ -0,0 +1,222 @@ +<?php +///////////////////////////////////////////////////////////////// +/// getID3() by James Heinrich <info@getid3.org> // +// available at http://getid3.sourceforge.net // +// or http://www.getid3.org // +///////////////////////////////////////////////////////////////// +// // +// 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 = $getID3->analyze('file2.wv'); +* +* +* Supported Cache Types +* +* SQL Databases: (use extension.cache.mysql) +* +* cache_type cache_options +* ------------------------------------------------------------------- +* mysql host, database, username, password +* +* +* DBM-Style Databases: (this extension) +* +* cache_type cache_options +* ------------------------------------------------------------------- +* gdbm dbm_filename, lock_filename +* ndbm dbm_filename, lock_filename +* db2 dbm_filename, lock_filename +* db3 dbm_filename, lock_filename +* db4 dbm_filename, lock_filename (PHP5 required) +* +* PHP must have write access to both dbm_filename and lock_filename. +* +* +* Recommended Cache Types +* +* Infrequent updates, many reads any DBM +* Frequent updates mysql +*/ + + +class getID3_cached_dbm extends getID3 +{ + + // public: constructor - see top of this file for cache type and cache_options + function getID3_cached_dbm($cache_type, $dbm_filename, $lock_filename) { + + // Check for dba extension + if (!extension_loaded('dba')) { + die('PHP is not compiled with dba support, required to use DBM style cache.'); + } + + // Check for specific dba driver + if (function_exists('dba_handlers')) { // PHP 4.3.0+ + if (!in_array('db3', dba_handlers())) { + die('PHP is not compiled --with '.$cache_type.' support, required to use DBM style cache.'); + } + } + else { // PHP <= 4.2.3 + ob_start(); // nasty, buy the only way to check... + phpinfo(); + $contents = ob_get_contents(); + ob_end_clean(); + if (!strstr($contents, $cache_type)) { + die('PHP is not compiled --with '.$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) { + $this->clear_cache(); + } + + parent::getID3(); + } + + + + // public: destuctor + function __destruct() { + + // Close dbm file + @dba_close($this->dba); + + // Release exclusive lock + @flock($this->lock, LOCK_UN); + + // Close lock file + @fclose($this->lock); + } + + + + // public: clear cache + 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 + 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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