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www.mikescher.com/framework/caching/dependencies/CDirectoryCacheDependency.php

136 lines
4.8 KiB
PHP

<?php
/**
* CDirectoryCacheDependency class file.
*
* @author Qiang Xue <qiang.xue@gmail.com>
* @link http://www.yiiframework.com/
* @copyright 2008-2013 Yii Software LLC
* @license http://www.yiiframework.com/license/
*/
/**
* CDirectoryCacheDependency represents a dependency based on change of a directory.
*
* CDirectoryCacheDependency performs dependency checking based on the
* modification time of the files contained in the specified directory.
* The directory being checked is specified via {@link directory}.
*
* By default, all files under the specified directory and subdirectories
* will be checked. If the last modification time of any of them is changed
* or if different number of files are contained in a directory, the dependency
* is reported as changed. By specifying {@link recursiveLevel},
* one can limit the checking to a certain depth of the directory.
*
* Note, dependency checking for a directory is expensive because it involves
* accessing modification time of multiple files under the directory.
*
* @author Qiang Xue <qiang.xue@gmail.com>
* @package system.caching.dependencies
* @since 1.0
*/
class CDirectoryCacheDependency extends CCacheDependency
{
/**
* @var string the directory whose change is used to determine if the dependency has been changed.
* If any of the files under the directory is changed, the dependency is considered as changed.
*/
public $directory;
/**
* @var integer the depth of the subdirectories to be recursively checked.
* If the value is less than 0, it means unlimited depth.
* If the value is 0, it means checking the files directly under the specified directory.
*/
public $recursiveLevel=-1;
/**
* @var string the regular expression matching valid file/directory names.
* Only the matching files or directories will be checked for changes.
* Defaults to null, meaning all files/directories will qualify.
*/
public $namePattern;
/**
* Constructor.
* @param string $directory the directory to be checked
*/
public function __construct($directory=null)
{
$this->directory=$directory;
}
/**
* Generates the data needed to determine if dependency has been changed.
* This method returns the modification timestamps for files under the directory.
* @throws CException if {@link directory} is empty
* @return mixed the data needed to determine if dependency has been changed.
*/
protected function generateDependentData()
{
if($this->directory!==null)
return $this->generateTimestamps($this->directory);
else
throw new CException(Yii::t('yii','CDirectoryCacheDependency.directory cannot be empty.'));
}
/**
* Determines the last modification time for files under the directory.
* This method may go recursively into subdirectories if {@link recursiveLevel} is not 0.
* @param string $directory the directory name
* @param integer $level level of the recursion
* @throws CException if given directory is not valid
* @return array list of file modification time indexed by the file path
*/
protected function generateTimestamps($directory,$level=0)
{
if(($dir=@opendir($directory))===false)
throw new CException(Yii::t('yii','"{path}" is not a valid directory.',
array('{path}'=>$directory)));
$timestamps=array();
while(($file=readdir($dir))!==false)
{
$path=$directory.DIRECTORY_SEPARATOR.$file;
if($file==='.' || $file==='..')
continue;
if($this->namePattern!==null && !preg_match($this->namePattern,$file))
continue;
if(is_file($path))
{
if($this->validateFile($path))
$timestamps[$path]=filemtime($path);
}
else
{
if(($this->recursiveLevel<0 || $level<$this->recursiveLevel) && $this->validateDirectory($path))
$timestamps=array_merge($timestamps, $this->generateTimestamps($path,$level+1));
}
}
closedir($dir);
return $timestamps;
}
/**
* Checks to see if the file should be checked for dependency.
* This method is invoked when dependency of the whole directory is being checked.
* By default, it always returns true, meaning the file should be checked.
* You may override this method to check only certain files.
* @param string $fileName the name of the file that may be checked for dependency.
* @return boolean whether this file should be checked.
*/
protected function validateFile($fileName)
{
return true;
}
/**
* Checks to see if the specified subdirectory should be checked for dependency.
* This method is invoked when dependency of the whole directory is being checked.
* By default, it always returns true, meaning the subdirectory should be checked.
* You may override this method to check only certain subdirectories.
* @param string $directory the name of the subdirectory that may be checked for dependency.
* @return boolean whether this subdirectory should be checked.
*/
protected function validateDirectory($directory)
{
return true;
}
}