ILIAS  release_5-1 Revision 5.0.0-5477-g43f3e3fab5f
extension.cache.dbm.php
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1<?php
4// available at http://getid3.sourceforge.net //
5// or http://www.getid3.org //
7// //
8// extension.cache.dbm.php - part of getID3() //
9// Please see readme.txt for more information //
10// ///
12// //
13// This extension written by Allan Hansen <ahØartemis*dk> //
14// ///
16
17
73{
74
75 // public: constructor - see top of this file for cache type and cache_options
76 function getID3_cached_dbm($cache_type, $dbm_filename, $lock_filename) {
77
78 // Check for dba extension
79 if (!extension_loaded('dba')) {
80 die('PHP is not compiled with dba support, required to use DBM style cache.');
81 }
82
83 // Check for specific dba driver
84 if (function_exists('dba_handlers')) { // PHP 4.3.0+
85 if (!in_array('db3', dba_handlers())) {
86 die('PHP is not compiled --with '.$cache_type.' support, required to use DBM style cache.');
87 }
88 }
89 else { // PHP <= 4.2.3
90 ob_start(); // nasty, buy the only way to check...
91 phpinfo();
92 $contents = ob_get_contents();
93 ob_end_clean();
94 if (!strstr($contents, $cache_type)) {
95 die('PHP is not compiled --with '.$cache_type.' support, required to use DBM style cache.');
96 }
97 }
98
99 // Create lock file if needed
100 if (!file_exists($lock_filename)) {
101 if (!touch($lock_filename)) {
102 die('failed to create lock file: ' . $lock_filename);
103 }
104 }
105
106 // Open lock file for writing
107 if (!is_writeable($lock_filename)) {
108 die('lock file: ' . $lock_filename . ' is not writable');
109 }
110 $this->lock = fopen($lock_filename, 'w');
111
112 // Acquire exclusive write lock to lock file
113 flock($this->lock, LOCK_EX);
114
115 // Create dbm-file if needed
116 if (!file_exists($dbm_filename)) {
117 if (!touch($dbm_filename)) {
118 die('failed to create dbm file: ' . $dbm_filename);
119 }
120 }
121
122 // Try to open dbm file for writing
123 $this->dba = @dba_open($dbm_filename, 'w', $cache_type);
124 if (!$this->dba) {
125
126 // Failed - create new dbm file
127 $this->dba = dba_open($dbm_filename, 'n', $cache_type);
128
129 if (!$this->dba) {
130 die('failed to create dbm file: ' . $dbm_filename);
131 }
132
133 // Insert getID3 version number
134 dba_insert(GETID3_VERSION, GETID3_VERSION, $this->dba);
135 }
136
137 // Init misc values
138 $this->cache_type = $cache_type;
139 $this->dbm_filename = $dbm_filename;
140
141 // Register destructor
142 register_shutdown_function(array($this, '__destruct'));
143
144 // Check version number and clear cache if changed
145 if (dba_fetch(GETID3_VERSION, $this->dba) != GETID3_VERSION) {
146 $this->clear_cache();
147 }
148
149 parent::getID3();
150 }
151
152
153
154 // public: destuctor
155 function __destruct() {
156
157 // Close dbm file
158 @dba_close($this->dba);
159
160 // Release exclusive lock
161 @flock($this->lock, LOCK_UN);
162
163 // Close lock file
164 @fclose($this->lock);
165 }
166
167
168
169 // public: clear cache
170 function clear_cache() {
171
172 // Close dbm file
173 dba_close($this->dba);
174
175 // Create new dbm file
176 $this->dba = dba_open($this->dbm_filename, 'n', $this->cache_type);
177
178 if (!$this->dba) {
179 die('failed to clear cache/recreate dbm file: ' . $this->dbm_filename);
180 }
181
182 // Insert getID3 version number
183 dba_insert(GETID3_VERSION, GETID3_VERSION, $this->dba);
184
185 // Reregister shutdown function
186 register_shutdown_function(array($this, '__destruct'));
187 }
188
189
190
191 // public: analyze file
192 function analyze($filename) {
193
194 if (file_exists($filename)) {
195
196 // Calc key filename::mod_time::size - should be unique
197 $key = $filename . '::' . filemtime($filename) . '::' . filesize($filename);
198
199 // Loopup key
200 $result = dba_fetch($key, $this->dba);
201
202 // Hit
203 if ($result !== false) {
204 return unserialize($result);
205 }
206 }
207
208 // Miss
209 $result = parent::analyze($filename);
210
211 // Save result
212 if (file_exists($filename)) {
213 dba_insert($key, serialize($result), $this->dba);
214 }
215
216 return $result;
217 }
218
219}
220
221
222?>
$result
getID3() by James Heinrich info@getid3.org //
getID3_cached_dbm($cache_type, $dbm_filename, $lock_filename)
$filename
Definition: getid3.php:46
const GETID3_VERSION
getID3() by James Heinrich info@getid3.org //
Definition: getid3.php:13