/vendors/phpgacl/Cache_Lite/Lite.php
PHP | 615 lines | 280 code | 44 blank | 291 comment | 62 complexity | e1e82a361b88cc5b7f140f5ba14b7380 MD5 | raw file
Possible License(s): LGPL-2.1
- <?php
- /**
- * Fast, light and safe Cache Class
- *
- * Cache_Lite is a fast, light and safe cache system. It's optimized
- * for file containers. It is fast and safe (because it uses file
- * locking and/or anti-corruption tests).
- *
- * There are some examples in the 'docs/examples' file
- * Technical choices are described in the 'docs/technical' file
- *
- * A tutorial is available in english at this url :
- * http://www.pearfr.org/index.php/en/article/cache_lite
- * (big thanks to Pierre-Alain Joye for the translation)
- *
- * The same tutorial is also available in french at this url :
- * http://www.pearfr.org/index.php/fr/article/cache_lite
- *
- * Memory Caching is from an original idea of
- * Mike BENOIT <ipso@snappymail.ca>
- *
- * @package Cache_Lite
- * @category Caching
- * @version $Id: Lite.php 376 2004-11-08 00:47:05Z ipso $
- * @author Fabien MARTY <fab@php.net>
- */
- define('CACHE_LITE_ERROR_RETURN', 1);
- define('CACHE_LITE_ERROR_DIE', 8);
- class Cache_Lite
- {
- // --- Private properties ---
- /**
- * Directory where to put the cache files
- * (make sure to add a trailing slash)
- *
- * @var string $_cacheDir
- */
- var $_cacheDir = '/tmp/';
- /**
- * Enable / disable caching
- *
- * (can be very usefull for the debug of cached scripts)
- *
- * @var boolean $_caching
- */
- var $_caching = true;
- /**
- * Cache lifetime (in seconds)
- *
- * @var int $_lifeTime
- */
- var $_lifeTime = 3600;
- /**
- * Enable / disable fileLocking
- *
- * (can avoid cache corruption under bad circumstances)
- *
- * @var boolean $_fileLocking
- */
- var $_fileLocking = true;
- /**
- * Timestamp of the last valid cache
- *
- * @var int $_refreshTime
- */
- var $_refreshTime;
- /**
- * File name (with path)
- *
- * @var string $_file
- */
- var $_file;
- /**
- * Enable / disable write control (the cache is read just after writing to detect corrupt entries)
- *
- * Enable write control will lightly slow the cache writing but not the cache reading
- * Write control can detect some corrupt cache files but maybe it's not a perfect control
- *
- * @var boolean $_writeControl
- */
- var $_writeControl = true;
- /**
- * Enable / disable read control
- *
- * If enabled, a control key is embeded in cache file and this key is compared with the one
- * calculated after the reading.
- *
- * @var boolean $_writeControl
- */
- var $_readControl = true;
- /**
- * Type of read control (only if read control is enabled)
- *
- * Available values are :
- * 'md5' for a md5 hash control (best but slowest)
- * 'crc32' for a crc32 hash control (lightly less safe but faster, better choice)
- * 'strlen' for a length only test (fastest)
- *
- * @var boolean $_readControlType
- */
- var $_readControlType = 'crc32';
- /**
- * Pear error mode (when raiseError is called)
- *
- * (see PEAR doc)
- *
- * @see setToDebug()
- * @var int $_pearErrorMode
- */
- var $_pearErrorMode = CACHE_LITE_ERROR_RETURN;
-
- /**
- * Current cache id
- *
- * @var string $_id
- */
- var $_id;
- /**
- * Current cache group
- *
- * @var string $_group
- */
- var $_group;
- /**
- * Enable / Disable "Memory Caching"
- *
- * NB : There is no lifetime for memory caching !
- *
- * @var boolean $_memoryCaching
- */
- var $_memoryCaching = false;
- /**
- * Enable / Disable "Only Memory Caching"
- * (be carefull, memory caching is "beta quality")
- *
- * @var boolean $_onlyMemoryCaching
- */
- var $_onlyMemoryCaching = false;
- /**
- * Memory caching array
- *
- * @var array $_memoryCachingArray
- */
- var $_memoryCachingArray = array();
- /**
- * Memory caching counter
- *
- * @var int $memoryCachingCounter
- */
- var $_memoryCachingCounter = 0;
- /**
- * Memory caching limit
- *
- * @var int $memoryCachingLimit
- */
- var $_memoryCachingLimit = 1000;
-
- /**
- * File Name protection
- *
- * if set to true, you can use any cache id or group name
- * if set to false, it can be faster but cache ids and group names
- * will be used directly in cache file names so be carefull with
- * special characters...
- *
- * @var boolean $fileNameProtection
- */
- var $_fileNameProtection = true;
-
- /**
- * Enable / disable automatic serialization
- *
- * it can be used to save directly datas which aren't strings
- * (but it's slower)
- *
- * @var boolean $_serialize
- */
- var $_automaticSerialization = false;
-
- // --- Public methods ---
- /**
- * Constructor
- *
- * $options is an assoc. Available options are :
- * $options = array(
- * 'cacheDir' => directory where to put the cache files (string),
- * 'caching' => enable / disable caching (boolean),
- * 'lifeTime' => cache lifetime in seconds (int),
- * 'fileLocking' => enable / disable fileLocking (boolean),
- * 'writeControl' => enable / disable write control (boolean),
- * 'readControl' => enable / disable read control (boolean),
- * 'readControlType' => type of read control 'crc32', 'md5', 'strlen' (string),
- * 'pearErrorMode' => pear error mode (when raiseError is called) (cf PEAR doc) (int),
- * 'memoryCaching' => enable / disable memory caching (boolean),
- * 'onlyMemoryCaching' => enable / disable only memory caching (boolean),
- * 'memoryCachingLimit' => max nbr of records to store into memory caching (int),
- * 'fileNameProtection' => enable / disable automatic file name protection (boolean),
- * 'automaticSerialization' => enable / disable automatic serialization (boolean)
- * );
- *
- * @param array $options options
- * @access public
- */
- function Cache_Lite($options = array(NULL))
- {
- $availableOptions = array('automaticSerialization', 'fileNameProtection', 'memoryCaching', 'onlyMemoryCaching', 'memoryCachingLimit', 'cacheDir', 'caching', 'lifeTime', 'fileLocking', 'writeControl', 'readControl', 'readControlType', 'pearErrorMode');
- foreach($options as $key => $value) {
- if(in_array($key, $availableOptions)) {
- $property = '_'.$key;
- $this->$property = $value;
- }
- }
- $this->_refreshTime = time() - $this->_lifeTime;
- }
-
- /**
- * Test if a cache is available and (if yes) return it
- *
- * @param string $id cache id
- * @param string $group name of the cache group
- * @param boolean $doNotTestCacheValidity if set to true, the cache validity won't be tested
- * @return string data of the cache (or false if no cache available)
- * @access public
- */
- function get($id, $group = 'default', $doNotTestCacheValidity = false)
- {
- $this->_id = $id;
- $this->_group = $group;
- $data = false;
- if ($this->_caching) {
- $this->_setFileName($id, $group);
- if ($this->_memoryCaching) {
- if (isset($this->_memoryCachingArray[$this->_file])) {
- if ($this->_automaticSerialization) {
- return unserialize($this->_memoryCachingArray[$this->_file]);
- } else {
- return $this->_memoryCachingArray[$this->_file];
- }
- } else {
- if ($this->_onlyMemoryCaching) {
- return false;
- }
- }
- }
- if ($doNotTestCacheValidity) {
- if (file_exists($this->_file)) {
- $data = $this->_read();
- }
- } else {
- if ((file_exists($this->_file)) && (@filemtime($this->_file) > $this->_refreshTime)) {
- $data = $this->_read();
- }
- }
- if (($data) and ($this->_memoryCaching)) {
- $this->_memoryCacheAdd($this->_file, $data);
- }
- if (($this->_automaticSerialization) and (is_string($data))) {
- $data = unserialize($data);
- }
- return $data;
- }
- return false;
- }
-
- /**
- * Save some data in a cache file
- *
- * @param string $data data to put in cache (can be another type than strings if automaticSerialization is on)
- * @param string $id cache id
- * @param string $group name of the cache group
- * @return boolean true if no problem
- * @access public
- */
- function save($data, $id = NULL, $group = 'default')
- {
- if ($this->_caching) {
- if ($this->_automaticSerialization) {
- $data = serialize($data);
- }
- if (isset($id)) {
- $this->_setFileName($id, $group);
- }
- if ($this->_memoryCaching) {
- $this->_memoryCacheAdd($this->_file, $data);
- if ($this->_onlyMemoryCaching) {
- return true;
- }
- }
- if ($this->_writeControl) {
- if (!$this->_writeAndControl($data)) {
- @touch($this->_file, time() - 2*abs($this->_lifeTime));
- return false;
- } else {
- return true;
- }
- } else {
- return $this->_write($data);
- }
- }
- return false;
- }
- /**
- * Remove a cache file
- *
- * @param string $id cache id
- * @param string $group name of the cache group
- * @return boolean true if no problem
- * @access public
- */
- function remove($id, $group = 'default')
- {
- $this->_setFileName($id, $group);
- if ($this->_memoryCaching) {
- if (isset($this->_memoryCachingArray[$this->_file])) {
- unset($this->_memoryCachingArray[$this->_file]);
- $this->_memoryCachingCounter = $this->_memoryCachingCounter - 1;
- }
- if ($this->_onlyMemoryCaching) {
- return true;
- }
- }
- if (!@unlink($this->_file)) {
- $this->raiseError('Cache_Lite : Unable to remove cache !', -3);
- return false;
- }
- return true;
- }
- /**
- * Clean the cache
- *
- * if no group is specified all cache files will be destroyed
- * else only cache files of the specified group will be destroyed
- *
- * @param string $group name of the cache group
- * @return boolean true if no problem
- * @access public
- */
- function clean($group = false)
- {
- if ($this->_fileNameProtection) {
- $motif = ($group) ? 'cache_'.md5($group).'_' : 'cache_';
- } else {
- $motif = ($group) ? 'cache_'.$group.'_' : 'cache_';
- }
- if ($this->_memoryCaching) {
- while (list($key, $value) = each($this->_memoryCachingArray)) {
- if (strpos($key, $motif, 0)) {
- unset($this->_memoryCachingArray[$key]);
- $this->_memoryCachingCounter = $this->_memoryCachingCounter - 1;
- }
- }
- if ($this->_onlyMemoryCaching) {
- return true;
- }
- }
- if (!($dh = opendir($this->_cacheDir))) {
- $this->raiseError('Cache_Lite : Unable to open cache directory !', -4);
- return false;
- }
- while ($file = readdir($dh)) {
- if (($file != '.') && ($file != '..')) {
- $file = $this->_cacheDir . $file;
- if (is_file($file)) {
- if (strpos($file, $motif, 0)) {
- if (!@unlink($file)) {
- $this->raiseError('Cache_Lite : Unable to remove cache !', -3);
- return false;
- }
- }
- }
- }
- }
- return true;
- }
-
- /**
- * Set to debug mode
- *
- * When an error is found, the script will stop and the message will be displayed
- * (in debug mode only).
- *
- * @access public
- */
- function setToDebug()
- {
- $this->_pearErrorMode = CACHE_LITE_ERROR_DIE;
- }
- /**
- * Set a new life time
- *
- * @param int $newLifeTime new life time (in seconds)
- * @access public
- */
- function setLifeTime($newLifeTime)
- {
- $this->_lifeTime = $newLifeTime;
- $this->_refreshTime = time() - $newLifeTime;
- }
- /**
- *
- * @access public
- */
- function saveMemoryCachingState($id, $group = 'default')
- {
- if ($this->_caching) {
- $array = array(
- 'counter' => $this->_memoryCachingCounter,
- 'array' => $this->_memoryCachingState
- );
- $data = serialize($array);
- $this->save($data, $id, $group);
- }
- }
- /**
- *
- * @access public
- */
- function getMemoryCachingState($id, $group = 'default', $doNotTestCacheValidity = false)
- {
- if ($this->_caching) {
- if ($data = $this->get($id, $group, $doNotTestCacheValidity)) {
- $array = unserialize($data);
- $this->_memoryCachingCounter = $array['counter'];
- $this->_memoryCachingArray = $array['array'];
- }
- }
- }
-
- /**
- * Return the cache last modification time
- *
- * BE CAREFUL : THIS METHOD IS FOR HACKING ONLY !
- *
- * @return int last modification time
- */
- function lastModified() {
- return filemtime($this->_file);
- }
-
- /**
- * Trigger a PEAR error
- *
- * To improve performances, the PEAR.php file is included dynamically.
- * The file is so included only when an error is triggered. So, in most
- * cases, the file isn't included and perfs are much better.
- *
- * @param string $msg error message
- * @param int $code error code
- * @access public
- */
- function raiseError($msg, $code)
- {
- include_once('PEAR.php');
- PEAR::raiseError($msg, $code, $this->_pearErrorMode);
- }
- // --- Private methods ---
- /**
- *
- * @access private
- */
- function _memoryCacheAdd($id, $data)
- {
- $this->_memoryCachingArray[$this->_file] = $data;
- if ($this->_memoryCachingCounter >= $this->_memoryCachingLimit) {
- list($key, $value) = each($this->_memoryCachingArray);
- unset($this->_memoryCachingArray[$key]);
- } else {
- $this->_memoryCachingCounter = $this->_memoryCachingCounter + 1;
- }
- }
- /**
- * Make a file name (with path)
- *
- * @param string $id cache id
- * @param string $group name of the group
- * @access private
- */
- function _setFileName($id, $group)
- {
- if ($this->_fileNameProtection) {
- $this->_file = ($this->_cacheDir.'cache_'.md5($group).'_'.md5($id));
- } else {
- $this->_file = $this->_cacheDir.'cache_'.$group.'_'.$id;
- }
- }
-
- /**
- * Read the cache file and return the content
- *
- * @return string content of the cache file
- * @access private
- */
- function _read()
- {
- $fp = @fopen($this->_file, "rb");
- if ($this->_fileLocking) @flock($fp, LOCK_SH);
- if ($fp) {
- clearstatcache(); // because the filesize can be cached by PHP itself...
- $length = @filesize($this->_file);
- $mqr = get_magic_quotes_runtime();
- set_magic_quotes_runtime(0);
- if ($this->_readControl) {
- $hashControl = @fread($fp, 32);
- $length = $length - 32;
- }
- $data = @fread($fp, $length);
- set_magic_quotes_runtime($mqr);
- if ($this->_fileLocking) @flock($fp, LOCK_UN);
- @fclose($fp);
- if ($this->_readControl) {
- $hashData = $this->_hash($data, $this->_readControlType);
- if ($hashData != $hashControl) {
- @touch($this->_file, time() - 2*abs($this->_lifeTime));
- return false;
- }
- }
- return $data;
- }
- $this->raiseError('Cache_Lite : Unable to read cache !', -2);
- return false;
- }
-
- /**
- * Write the given data in the cache file
- *
- * @param string $data data to put in cache
- * @return boolean true if ok
- * @access private
- */
- function _write($data)
- {
- $fp = @fopen($this->_file, "wb");
- if ($fp) {
- if ($this->_fileLocking) @flock($fp, LOCK_EX);
- if ($this->_readControl) {
- @fwrite($fp, $this->_hash($data, $this->_readControlType), 32);
- }
- $len = strlen($data);
- @fwrite($fp, $data, $len);
- if ($this->_fileLocking) @flock($fp, LOCK_UN);
- @fclose($fp);
- return true;
- }
- $this->raiseError('Cache_Lite : Unable to write cache !', -1);
- return false;
- }
-
- /**
- * Write the given data in the cache file and control it just after to avoir corrupted cache entries
- *
- * @param string $data data to put in cache
- * @return boolean true if the test is ok
- * @access private
- */
- function _writeAndControl($data)
- {
- $this->_write($data);
- $dataRead = $this->_read($data);
- return ($dataRead==$data);
- }
-
- /**
- * Make a control key with the string containing datas
- *
- * @param string $data data
- * @param string $controlType type of control 'md5', 'crc32' or 'strlen'
- * @return string control key
- * @access private
- */
- function _hash($data, $controlType)
- {
- switch ($controlType) {
- case 'md5':
- return md5($data);
- case 'crc32':
- return sprintf('% 32d', crc32($data));
- case 'strlen':
- return sprintf('% 32d', strlen($data));
- default:
- $this->raiseError('Unknown controlType ! (available values are only \'md5\', \'crc32\', \'strlen\')', -5);
- }
- }
-
- }
- ?>