framework/caching/FileCache.php
<?php
/**
* @link https://www.yiiframework.com/
* @copyright Copyright (c) 2008 Yii Software LLC
* @license https://www.yiiframework.com/license/
*/
namespace yii\caching;
use Yii;
use yii\helpers\FileHelper;
/**
* FileCache implements a cache component using files.
*
* For each data value being cached, FileCache will store it in a separate file.
* The cache files are placed under [[cachePath]]. FileCache will perform garbage collection
* automatically to remove expired cache files.
*
* Please refer to [[Cache]] for common cache operations that are supported by FileCache.
*
* For more details and usage information on Cache, see the [guide article on caching](guide:caching-overview).
*
* @author Qiang Xue <qiang.xue@gmail.com>
* @since 2.0
*/
class FileCache extends Cache
{
/**
* @var string a string prefixed to every cache key. This is needed when you store
* cache data under the same [[cachePath]] for different applications to avoid
* conflict.
*
* To ensure interoperability, only alphanumeric characters should be used.
*/
public $keyPrefix = '';
/**
* @var string the directory to store cache files. You may use [path alias](guide:concept-aliases) here.
* If not set, it will use the "cache" subdirectory under the application runtime path.
*/
public $cachePath = '@runtime/cache';
/**
* @var string cache file suffix. Defaults to '.bin'.
*/
public $cacheFileSuffix = '.bin';
/**
* @var int the level of sub-directories to store cache files. Defaults to 1.
* If the system has huge number of cache files (e.g. one million), you may use a bigger value
* (usually no bigger than 3). Using sub-directories is mainly to ensure the file system
* is not over burdened with a single directory having too many files.
*/
public $directoryLevel = 1;
/**
* @var int the probability (parts per million) that garbage collection (GC) should be performed
* when storing a piece of data in the cache. Defaults to 10, meaning 0.001% chance.
* This number should be between 0 and 1000000. A value 0 means no GC will be performed at all.
*/
public $gcProbability = 10;
/**
* @var int|null the permission to be set for newly created cache files.
* This value will be used by PHP chmod() function. No umask will be applied.
* If not set, the permission will be determined by the current environment.
*/
public $fileMode;
/**
* @var int the permission to be set for newly created directories.
* This value will be used by PHP chmod() function. No umask will be applied.
* Defaults to 0775, meaning the directory is read-writable by owner and group,
* but read-only for other users.
*/
public $dirMode = 0775;
/**
* Initializes this component by ensuring the existence of the cache path.
*/
public function init()
{
parent::init();
$this->cachePath = Yii::getAlias($this->cachePath);
if (!is_dir($this->cachePath)) {
FileHelper::createDirectory($this->cachePath, $this->dirMode, true);
}
}
/**
* Checks whether a specified key exists in the cache.
* This can be faster than getting the value from the cache if the data is big.
* Note that this method does not check whether the dependency associated
* with the cached data, if there is any, has changed. So a call to [[get]]
* may return false while exists returns true.
* @param mixed $key a key identifying the cached value. This can be a simple string or
* a complex data structure consisting of factors representing the key.
* @return bool true if a value exists in cache, false if the value is not in the cache or expired.
*/
public function exists($key)
{
$cacheFile = $this->getCacheFile($this->buildKey($key));
return @filemtime($cacheFile) > time();
}
/**
* Retrieves a value from cache with a specified key.
* This is the implementation of the method declared in the parent class.
* @param string $key a unique key identifying the cached value
* @return string|false the value stored in cache, false if the value is not in the cache or expired.
*/
protected function getValue($key)
{
$cacheFile = $this->getCacheFile($key);
if (@filemtime($cacheFile) > time()) {
$fp = @fopen($cacheFile, 'r');
if ($fp !== false) {
@flock($fp, LOCK_SH);
$cacheValue = @stream_get_contents($fp);
@flock($fp, LOCK_UN);
@fclose($fp);
return $cacheValue;
}
}
return false;
}
/**
* Stores a value identified by a key in cache.
* This is the implementation of the method declared in the parent class.
*
* @param string $key the key identifying the value to be cached
* @param string $value the value to be cached. Other types (If you have disabled [[serializer]]) unable to get is
* correct in [[getValue()]].
* @param int $duration the number of seconds in which the cached value will expire. Fewer than or equal to 0 means 1 year expiration time.
* @return bool true if the value is successfully stored into cache, false otherwise
*/
protected function setValue($key, $value, $duration)
{
$this->gc();
$cacheFile = $this->getCacheFile($key);
if ($this->directoryLevel > 0) {
@FileHelper::createDirectory(dirname($cacheFile), $this->dirMode, true);
}
// If ownership differs the touch call will fail, so we try to
// rebuild the file from scratch by deleting it first
// https://github.com/yiisoft/yii2/pull/16120
if (is_file($cacheFile) && function_exists('posix_geteuid') && fileowner($cacheFile) !== posix_geteuid()) {
@unlink($cacheFile);
}
if (@file_put_contents($cacheFile, $value, LOCK_EX) !== false) {
if ($this->fileMode !== null) {
@chmod($cacheFile, $this->fileMode);
}
if ($duration <= 0) {
$duration = 31536000; // 1 year
}
return @touch($cacheFile, $duration + time());
}
$error = error_get_last();
Yii::warning("Unable to write cache file '{$cacheFile}': {$error['message']}", __METHOD__);
return false;
}
/**
* Stores a value identified by a key into cache if the cache does not contain this key.
* This is the implementation of the method declared in the parent class.
*
* @param string $key the key identifying the value to be cached
* @param string $value the value to be cached. Other types (if you have disabled [[serializer]]) unable to get is
* correct in [[getValue()]].
* @param int $duration the number of seconds in which the cached value will expire. 0 means never expire.
* @return bool true if the value is successfully stored into cache, false otherwise
*/
protected function addValue($key, $value, $duration)
{
$cacheFile = $this->getCacheFile($key);
if (@filemtime($cacheFile) > time()) {
return false;
}
return $this->setValue($key, $value, $duration);
}
/**
* Deletes a value with the specified key from cache
* This is the implementation of the method declared in the parent class.
* @param string $key the key of the value to be deleted
* @return bool if no error happens during deletion
*/
protected function deleteValue($key)
{
$cacheFile = $this->getCacheFile($key);
return @unlink($cacheFile);
}
/**
* Returns the cache file path given the normalized cache key.
* @param string $normalizedKey normalized cache key by [[buildKey]] method
* @return string the cache file path
*/
protected function getCacheFile($normalizedKey)
{
$cacheKey = $normalizedKey;
if ($this->keyPrefix !== '') {
// Remove key prefix to avoid generating constant directory levels
$lenKeyPrefix = strlen($this->keyPrefix);
$cacheKey = substr_replace($normalizedKey, '', 0, $lenKeyPrefix);
}
$cachePath = $this->cachePath;
if ($this->directoryLevel > 0) {
for ($i = 0; $i < $this->directoryLevel; ++$i) {
if (($subDirectory = substr($cacheKey, $i + $i, 2)) !== false) {
$cachePath .= DIRECTORY_SEPARATOR . $subDirectory;
}
}
}
return $cachePath . DIRECTORY_SEPARATOR . $normalizedKey . $this->cacheFileSuffix;
}
/**
* Deletes all values from cache.
* This is the implementation of the method declared in the parent class.
* @return bool whether the flush operation was successful.
*/
protected function flushValues()
{
$this->gc(true, false);
return true;
}
/**
* Removes expired cache files.
* @param bool $force whether to enforce the garbage collection regardless of [[gcProbability]].
* Defaults to false, meaning the actual deletion happens with the probability as specified by [[gcProbability]].
* @param bool $expiredOnly whether to removed expired cache files only.
* If false, all cache files under [[cachePath]] will be removed.
*/
public function gc($force = false, $expiredOnly = true)
{
if ($force || random_int(0, 1000000) < $this->gcProbability) {
$this->gcRecursive($this->cachePath, $expiredOnly);
}
}
/**
* Recursively removing expired cache files under a directory.
* This method is mainly used by [[gc()]].
* @param string $path the directory under which expired cache files are removed.
* @param bool $expiredOnly whether to only remove expired cache files. If false, all files
* under `$path` will be removed.
*/
protected function gcRecursive($path, $expiredOnly)
{
if (($handle = opendir($path)) !== false) {
while (($file = readdir($handle)) !== false) {
if (strncmp($file, '.', 1) === 0) {
continue;
}
$fullPath = $path . DIRECTORY_SEPARATOR . $file;
if (is_dir($fullPath)) {
$this->gcRecursive($fullPath, $expiredOnly);
if (!$expiredOnly) {
if (!@rmdir($fullPath)) {
$error = error_get_last();
Yii::warning("Unable to remove directory '{$fullPath}': {$error['message']}", __METHOD__);
}
}
} elseif (!$expiredOnly || $expiredOnly && @filemtime($fullPath) < time()) {
if (!@unlink($fullPath)) {
$error = error_get_last();
Yii::warning("Unable to remove file '{$fullPath}': {$error['message']}", __METHOD__);
}
}
}
closedir($handle);
}
}
}