etsis_Cache_Cookie ()
eduTrac SIS Cookie Cache Class.
Source file: app/src/Core/Cache/etsis_Cache_Cookie.php
Methods
- __construct
- _exists — Serves as a utility method to determine whether a key exists in the cache.
- cacheHits — Counts the number of cache hits and writes it to a file.
- cacheMisses — Counts the number of cache misses and writes it to a file.
- create — Creates the cache file.
- dec — Decrements numeric cache item's value.
- delete — Deletes a cache file based on unique key.
- flush — Flushes the file system cache completely.
- flushNamespace — Removes all cache items from a particular namespace.
- getStats — Echoes the stats of the cache.
- inc — Increments numeric cache item's value.
- keyToPath — Retrieve the cache file.
- read — Fetches cached data.
- remove_dir — Deletes cache/namespace directory.
- removeStaleCache — Removes any and all stale items from the cache.
- set — Sets the data contents into the cache.
- uniqueKey — Generates a unique cache key.
- update — Updates a cache file based on unique ID.
Source
class etsis_Cache_Cookie extends \app\src\Core\Cache\etsis_Abstract_Cache
{
/**
* Holds the application object.
*
* @since 6.2.0
* @var object
*/
public $app;
/**
* Cache directory object.
*
* @since 6.2.0
* @var string
*/
protected $_dir;
/**
* Holds the cached objects.
*
* @since 6.2.0
* @var array
*/
protected $_cache = [];
/**
* Holds the memory limit object.
*
* @since 6.2.0
* @var int
*/
protected $_memory_limit;
/**
* Holds the memory limit object
*
* @since 6.2.0
* @var int
*/
protected $_memory_low;
/**
* Should the cache persist or not.
*
* @since 6.2.0
* @var bool
*/
public $persist;
/**
* Sets if cache is enabled or not.
*
* @since 6.2.0
* @var bool
*/
public $enable;
public function __construct(\Liten\Liten $liten = null)
{
$this->app = !empty($liten) ? $liten : \Liten\Liten::getInstance();
if (ETSIS_FILE_CACHE_LOW_RAM && function_exists('memory_get_usage')) {
$limit = _trim(ini_get('memory_limit'));
$mod = strtolower($limit[strlen($limit) - 1]);
switch ($mod) {
case 'g':
$limit *= 1073741824;
break;
case 'm':
$limit *= 1048576;
break;
case 'k':
$limit *= 1024;
break;
}
if ($limit <= 0) {
$limit = 0;
}
$this->_memory_limit = $limit;
$limit = _trim(ETSIS_FILE_CACHE_LOW_RAM);
$mod = strtolower($limit[strlen($limit) - 1]);
switch ($mod) {
case 'g':
$limit *= 1073741824;
break;
case 'm':
$limit *= 1048576;
break;
case 'k':
$limit *= 1024;
break;
}
$this->_memory_low = $limit;
} else {
$this->_memory_limit = 0;
$this->_memory_low = 0;
}
/**
* Filter sets whether caching is enabled or not.
*
* @since 6.2.0
* @var bool
*/
$this->enable = $this->app->hook->apply_filter('enable_caching', true);
$this->persist = $this->enable && true;
/**
* File system cache directory.
*/
$dir = $this->app->config('file.savepath') . 'cache';
/**
* Fiter the file cache directory in order to override it
* in case some systems are having issues.
*
* @since 6.2.0
* @param string $dir
* The directory where file system cache files are saved.
*/
$cacheDir = $this->app->hook->apply_filter('filesystem_cache_dir', $dir);
/**
* If the cache directory does not exist, the create it first
* before trying to call it for use.
*/
if (!is_dir($cacheDir) || !etsis_file_exists($cacheDir, false)) {
try {
_mkdir($cacheDir);
} catch (IOException $e) {
Cascade::getLogger('error')->error(sprintf('IOSTATE[%s]: Forbidden: %s', $e->getCode(), $e->getMessage()));
} catch (Exception $e) {
Cascade::getLogger('error')->error(sprintf('IOSTATE[%s]: Forbidden: %s', $e->getCode(), $e->getMessage()));
}
}
/**
* If the directory isn't writable, throw an exception.
*/
if (!etsis_is_writable($cacheDir)) {
throw new IOException(_t('Could not create the file cache directory.'));
}
/**
* Cache directory is set.
*/
$this->_dir = $cacheDir . DS;
}
/**
* Creates the cache file.
*
* {@inheritDoc}
*
* @see \app\src\Cache\etsis_Abstract_Cache::create()
*
* @since 6.2.0
* @param int|string $key
* Unique key of the cache file.
* @param mixed $data
* Data that should be cached.
* @param string $namespace
* Optional. Where to namespace the cache contents. Default: 'default'.
* @param int $ttl
* Time to live sets the life of the cache file. Default: 0 = expires immediately after request.
*/
public function create($key, $data, $namespace = 'default', $ttl = 0)
{
if (!$this->enable) {
return false;
}
if (empty($namespace)) {
$namespace = 'default';
}
return $this->set($key, $data, $namespace, (int) $ttl);
}
/**
* Fetches cached data.
*
* {@inheritDoc}
*
* @see \app\src\Cache\etsis_Abstract_Cache::read()
*
* @since 6.2.0
* @param int|string $key
* Unique key of the cache file.
* @param string $namespace
* Optional. Where the cache contents are namespaced. Default: 'default'.
*/
public function read($key, $namespace = 'default')
{
if (!$this->enable) {
return false;
}
if (empty($namespace)) {
$namespace = 'default';
}
$x = isset($this->app->req->cookie[md5($key)]) ? $this->app->req->cookie[md5($key)] : false;
if ($x == false) {
$this->cacheMisses();
return null;
} else {
if (!$this->_exists($key, $namespace)) {
$this->cacheMisses();
return false;
}
if (isset($this->_cache[$namespace], $this->_cache[$namespace][$key])) {
$this->cacheHits();
return $this->_cache[$namespace][$key];
}
$this->cacheHits();
$filename = $this->keyToPath($key, $namespace);
}
$get_data = _file_get_contents($filename, LOCK_EX);
$data = maybe_unserialize($get_data);
if ($this->persist) {
if ($this->_memory_limit) {
$usage = memory_get_usage();
if ($this->_memory_limit - $usage < $this->_memory_low) {
$this->cacheMisses();
return false;
}
}
$files = glob($filename);
if (empty($files) || !isset($files[0])) {
$this->cacheMisses();
return false;
}
if (is_readable($files[0])) {
$result = $files[0];
$time = $data[0] - file_mod_time($result);
$now = time();
if ((file_mod_time($result) + $time < $now)) {
$this->cacheMisses();
unlink($result);
return false;
}
if ((file_mod_time($result) + $time > $now)) {
$this->cacheHits();
settype($result, 'string');
$this->_cache[$namespace][$key] = $data[1];
$result = $this->_cache[$namespace][$key];
return is_object($result) ? clone ($result) : $result;
}
}
$this->app->cookies->remove(md5($key));
unlink($files[0]);
}
}
/**
* Updates a cache file based on unique ID.
* This method only exists for
* CRUD completeness purposes and just basically calls the create method.
*
* {@inheritDoc}
*
* @see \app\src\Cache\etsis_Abstract_Cache::update()
*
* @since 6.2.0
* @param int|string $key
* Unique key of the cache file.
* @param mixed $data
* Data that should be cached.
* @param string $namespace
* Optional. Where to namespace the cache contents. Default: 'default'.
* @param int $ttl
* Time to live sets the life of the cache file. Default: no expiration.
*/
public function update($key, $data, $namespace = 'default', $ttl = 0)
{
if (!$this->enable) {
return false;
}
if (empty($namespace)) {
$namespace = 'default';
}
return $this->create($key, $data, $namespace, (int) $ttl);
}
/**
* Deletes a cache file based on unique key.
*
* {@inheritDoc}
*
* @see \app\src\Cache\etsis_Abstract_Cache::delete()
*
* @since 6.2.0
* @param int|string $key
* Unique key of cache file.
* @param string $namespace
* Optional. Where to namespace the cache contents. Default: 'default'.
* @return bool Returns true if the cache was deleted or false otherwise.
*/
public function delete($key, $namespace = 'default')
{
if (empty($namespace)) {
$namespace = 'default';
}
unset($this->_cache[$namespace][$key]);
if (!$this->_exists($key, $namespace)) {
return false;
}
$this->app->cookies->remove(md5($key));
$filename = $this->keyToPath($key, $namespace);
return rename($filename, $filename . $this->inc($key, 1, $namespace));
}
/**
* Flushes the file system cache completely.
*
* {@inheritDoc}
*
* @see \app\src\Cache\etsis_Abstract_Cache::flush()
*
* @since 6.2.0
* @return bool Returns true if the cache was purged or false otherwise.
*/
public function flush()
{
$this->remove_dir($this->_dir);
$this->_cache = [];
return true;
}
/**
* Removes all cache items from a particular namespace.
*
* {@inheritDoc}
*
* @see \app\src\Cache\etsis_Abstract_Cache::flushNamespace()
*
* @since 6.2.0
* @param int|string $namespace
* Optional. Where the cache contents are namespaced. Default: 'default'.
* @return bool Returns true if the namespace was purged or false otherwise.
*/
public function flushNamespace($namespace = 'default')
{
if (empty($namespace)) {
$namespace = 'default';
}
$dir = $this->_dir . $namespace;
$this->remove_dir($dir);
return true;
}
/**
* Sets the data contents into the cache.
*
* {@inheritDoc}
*
* @see \app\src\Cache\etsis_Abstract_Cache::set()
*
* @since 6.2.0
* @param int|string $key
* Unique key of the cache file.
* @param mixed $data
* Data that should be cached.
* @param string $namespace
* Optional. Where the cache contents are namespaced. Default: 'default'.
* @param int $ttl
* Time to live sets the life of the cache file. Default: 0 = expires immediately after request.
* @return bool Returns true if the cache was set and false otherwise.
*/
public function set($key, $data, $namespace = 'default', $ttl = 0)
{
if (!$this->enable) {
return false;
}
if (empty($namespace)) {
$namespace = 'default';
}
/**
* Removes any and all stale items from the cache before
* adding more items to the specified namespace.
*/
$this->removeStaleCache($key, $namespace, (int) $ttl);
if ($this->_memory_limit) {
$usage = memory_get_usage();
if ($this->_memory_limit - $usage < $this->_memory_low) {
$this->app->cookies->remove(md5($key));
unlink($this->keyToPath($key, $namespace));
return false;
}
}
if (is_object($data)) {
$data = clone ($data);
}
$this->_cache[$namespace][$key] = $data;
$filename = $this->keyToPath($key, $namespace);
if ($this->_exists($key, $namespace)) {
return false;
}
// Opening the file in read/write mode
$h = fopen($filename, 'a+');
// If there is an issue with the handler, throw an exception.
if (!$h) {
throw new Exception(_t('Could not write to cache'), 'cookie_cache');
}
$this->app->cookies->set(md5($key), $key, $ttl);
// exclusive lock, will get released when the file is closed
flock($h, LOCK_EX);
// go to the start of the file
fseek($h, 0);
// truncate the file
ftruncate($h, 0);
// Serializing along with the TTL
$data = maybe_serialize(array(
time() + (int) $ttl,
$data
));
if (fwrite($h, $data) === false) {
throw new IOException(_t('Could not write to cache'));
}
fclose($h);
return true;
}
/**
* Echoes the stats of the cache.
*
* Gives the cache hits, cache misses and cache uptime.
*
* @since 6.2.0
*/
public function getStats()
{
if (!$this->enable) {
return false;
}
echo "<p>";
echo "<strong>" . _t('Cache Hits:') . "</strong> " . _file_get_contents($this->_dir . 'cache_hits.txt') . "<br />";
echo "<strong>" . _t('Cache Misses:') . "</strong> " . _file_get_contents($this->_dir . 'cache_misses.txt') . "<br />";
echo "<strong>" . _t('Uptime:') . "</strong> " . timeAgo(file_mod_time($this->_dir)) . "<br />";
echo "</p>";
}
/**
* Increments numeric cache item's value.
*
* {@inheritDoc}
*
* @see \app\src\Cache\etsis_Abstract_Cache::inc()
*
* @since 6.2.0
* @param int|string $key
* The cache key to increment
* @param int $offset
* Optional. The amount by which to increment the item's value. Default: 1.
* @param string $namespace
* Optional. The namespace the key is in. Default: 'default'.
* @return false|int False on failure, the item's new value on success.
*/
public function inc($key, $offset = 1, $namespace = 'default')
{
if (empty($namespace)) {
$namespace = 'default';
}
if (!$this->_exists($key, $namespace)) {
return false;
}
if (!is_numeric($this->_cache[$namespace][$key])) {
$this->_cache[$namespace][$key] = 0;
}
$offset = (int) $offset;
$this->_cache[$namespace][$key] += $offset;
if ($this->_cache[$namespace][$key] < 0) {
$this->_cache[$namespace][$key] = 0;
}
return $this->_cache[$namespace][$key];
}
/**
* Decrements numeric cache item's value.
*
* {@inheritDoc}
*
* @see \app\src\Cache\etsis_Abstract_Cache::dec()
*
* @since 6.2.0
* @param int|string $key
* The cache key to decrement.
* @param int $offset
* Optional. The amount by which to decrement the item's value. Default: 1.
* @param string $namespace
* Optional. The namespace the key is in. Default: 'default'.
* @return false|int False on failure, the item's new value on success.
*/
public function dec($key, $offset = 1, $namespace = 'default')
{
if (empty($namespace)) {
$namespace = 'default';
}
if (!$this->_exists($key, $namespace)) {
return false;
}
if (!is_numeric($this->_cache[$namespace][$key])) {
$this->_cache[$namespace][$key] = 0;
}
$offset = (int) $offset;
$this->_cache[$namespace][$key] -= $offset;
if ($this->_cache[$namespace][$key] < 0) {
$this->_cache[$namespace][$key] = 0;
}
return $this->_cache[$namespace][$key];
}
/**
* Generates a unique cache key.
*
* {@inheritDoc}
*
* @see \app\src\Cache\etsis_Abstract_Cache::uniqueKey()
*
* @since 6.2.0
* @access protected
* @param int|string $key
* Unique key for cache file.
* @param string $namespace
* Optional. Where the cache contents are namespaced. Default: 'default'.
*/
protected function uniqueKey($key, $namespace = 'default')
{
if (empty($namespace)) {
$namespace = 'default';
}
return $this->_cache[$namespace][$key] = $namespace . ':' . $key;
}
/**
* Serves as a utility method to determine whether a key exists in the cache.
*
* {@inheritDoc}
*
* @see \app\src\Cache\etsis_Abstract_Cache::_exists()
*
* @since 6.2.0
* @access protected
* @param int|string $key
* Cache key to check for existence.
* @param string $namespace
* Cache namespace for the key existence check.
* @return bool Whether the cache item exists in the cache for the given key and namespace.
*/
protected function _exists($key, $namespace)
{
if (empty($namespace)) {
$namespace = 'default';
}
if (is_readable($this->keyToPath($key, $namespace))) {
return true;
}
}
/**
* Deletes cache/namespace directory.
*
* @since 6.2.0
* @param string $dir
* Directory that should be removed.
*/
protected function remove_dir($dir)
{
if (!is_dir($dir)) {
return;
}
$dh = opendir($dir);
if (!is_resource($dh)) {
return;
}
_rmdir($dir);
closedir($dh);
}
/**
* Counts the number of cache hits
* and writes it to a file.
*
* @since 6.2.0
*/
protected function cacheHits()
{
$filename = $this->_dir . 'cache_hits.txt';
if (!is_readable($filename)) {
$fp = fopen($filename, 'w');
fwrite($fp, 0);
fclose($fp);
return false;
}
$fp = fopen($filename, 'c+');
flock($fp, LOCK_EX);
$count = (int) fread($fp, filesize($filename));
ftruncate($fp, 0);
fseek($fp, 0);
fwrite($fp, $count + 1);
flock($fp, LOCK_UN);
fclose($fp);
}
/**
* Counts the number of cache misses
* and writes it to a file.
*
* @since 6.2.0
*/
protected function cacheMisses()
{
$filename = $this->_dir . 'cache_misses.txt';
if (!is_readable($filename)) {
$fp = fopen($filename, 'w');
fwrite($fp, 0);
fclose($fp);
return false;
}
$fp = fopen($filename, 'c+');
flock($fp, LOCK_EX);
$count = (int) fread($fp, filesize($filename));
ftruncate($fp, 0);
fseek($fp, 0);
fwrite($fp, $count + 1);
flock($fp, LOCK_UN);
fclose($fp);
}
/**
* Removes any and all stale items from the cache.
*
* @since 6.2.0
* @param int|string $key
* Unqiue key of cache.
* @param int|string $namespace
* Optional. Where the cache contents are namespaced. Default: 'default'.
* @param int $ttl
* Time to live sets the life of the cache file. Default: 0.
*/
protected function removeStaleCache($key, $namespace = 'default', $ttl = 0)
{
if (empty($namespace)) {
$namespace = 'default';
}
if (!$this->_exists($key, $namespace)) {
$this->app->cookies->remove(md5($key));
}
$stale = glob($this->_dir . $namespace . DS . '*');
if (is_array($stale)) {
foreach ($stale as $filename) {
if (etsis_file_exists($filename, false)) {
if (time() - file_mod_time($filename) > (int) $ttl) {
unlink($filename);
}
}
}
}
}
/**
* Retrieve the cache file.
*
* @since 6.2.0
* @access protected
* @param int|string $key
* Unqiue key of cache.
* @param int|string $namespace
* Optional. Where the cache contents are namespaced. Default: 'default'.
*/
private function keyToPath($key, $namespace)
{
$dir = $this->_dir . urlencode($namespace);
if (!etsis_file_exists($dir, false)) {
try {
_mkdir($dir);
} catch (IOException $e) {
Cascade::getLogger('error')->error(sprintf('IOSTATE[%s]: Forbidden: %s', $e->getCode(), $e->getMessage()));
return;
} catch (Exception $e) {
Cascade::getLogger('error')->error(sprintf('IOSTATE[%s]: Forbidden: %s', $e->getCode(), $e->getMessage()));
return;
}
}
return $this->_dir . urlencode($namespace) . DS . urlencode(md5($key));
}
}
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Changelog
- Since: eduTrac SIS 6.2.0