zhphp framewrok (二十二) file cache 文件缓存类

<?php
/**
* Created by JetBrains PhpStorm.
* User: 张华
* Date: 14-3-8
* Time: 下午12:21
* QQ: 746502560@qq.com
* To change this template use File | Settings | File Templates.
*/
class fileCache
{
private static $_instance = null;

protected $_options = array(
'cache_dir'        => "./",
'file_name_prefix' => 'cache',
'mode'            => '1', //mode 1 为serialize model 2为保存为可执行文件
);

/**
* 得到本类实例
*
* @return Ambiguous
*/
public static function getInstance()
{
if(self::$_instance === null)
{
self::$_instance = new self();
}
return self::$_instance;
}

/**
* 得到缓存信息
*
* @param string $id
* @return boolean|array
*/
public static function get($id)
{
$instance = self::getInstance();

//缓存文件不存在
if(!$instance->has($id))
{
return false;
}

$file = $instance->_file($id);

$data = $instance->_fileGetContents($file);

if($data['expire'] == 0 || time() < $data['expire'])
{
return $data['contents'];
}
return false;
}

/**
* 设置一个缓存
*
* @param string $id   缓存id
* @param array  $data 缓存内容
* @param int    $cacheLife 缓存生命 默认为0无限生命
*/
public static function set($id, $data, $cacheLife = 0)
{
$instance = self::getInstance();

$time = time();
$cache         = array();
$cache['contents'] = $data;
$cache['expire']   = $cacheLife === 0 ? 0 : $time + $cacheLife;
$cache['mtime']    = $time;

$file = $instance->_file($id);

return $instance->_filePutContents($file, $cache);
}

/**
* 清除一条缓存
*
* @param string cache id
* @return void
*/
public static function delete($id)
{
$instance = self::getInstance();

if(!$instance->has($id))
{
return false;
}
$file = $instance->_file($id);
//删除该缓存
return unlink($file);
}

/**
* 判断缓存是否存在
*
* @param string $id cache_id
* @return boolean true 缓存存在 false 缓存不存在
*/
public static function has($id)
{
$instance = self::getInstance();
$file     = $instance->_file($id);

if(!is_file($file))
{
return false;
}
return true;
}

/**
* 通过缓存id得到缓存信息路径
* @param string $id
* @return string 缓存文件路径
*/
protected function _file($id)
{
$instance  = self::getInstance();
$fileNmae  = $instance->_idToFileName($id);
return $instance->_options['cache_dir'] . $fileNmae;
}

/**
* 通过id得到缓存信息存储文件名
*
* @param  $id
* @return string 缓存文件名
*/
protected function _idToFileName($id)
{
$instance  = self::getInstance();
$prefix    = $instance->_options['file_name_prefix'];
return $prefix . '---' . $id;
}

/**
* 通过filename得到缓存id
*
* @param  $id
* @return string 缓存id
*/
protected function _fileNameToId($fileName)
{
$instance  = self::getInstance();
$prefix    = $instance->_options['file_name_prefix'];
return preg_replace('/^' . $prefix . '---(.*)$/', '$1', $fileName);
}

/**
* 把数据写入文件
*
* @param string $file 文件名称
* @param array  $contents 数据内容
* @return bool
*/
protected function _filePutContents($file, $contents)
{
if($this->_options['mode'] == 1)
{
$contents = serialize($contents);
}
else
{
$time = time();
$contents = "<?php\n".
" // mktime: ". $time. "\n".
" return ".
var_export($contents, true).
"\n?>";
}

$result = false;
$f = @fopen($file, 'w');
if ($f) {
@flock($f, LOCK_EX);
fseek($f, 0);
ftruncate($f, 0);
$tmp = @fwrite($f, $contents);
if (!($tmp === false)) {
$result = true;
}
@fclose($f);
}
@chmod($file,0777);
return $result;
}

/**
* 从文件得到数据
*
* @param  sring $file
* @return boolean|array
*/
protected function _fileGetContents($file)
{
if(!is_file($file))
{
return false;
}

if($this->_options['mode'] == 1)
{
$f = @fopen($file, 'r');
@$data = fread($f,filesize($file));
@fclose($f);
return unserialize($data);
}
else
{
return include $file;
}
}

/**
* 构造函数
*/
protected function __construct()
{

}

/**
* 设置缓存路径
*
* @param string $path
* @return self
*/
public static function setCacheDir($path)
{
$instance  = self::getInstance();
if (!is_dir($path)) {
exit('file_cache: ' . $path.' 不是一个有效路径 ');
}
if (!is_writable($path)) {
exit('file_cache: 路径 "'.$path.'" 不可写');
}

$path = rtrim($path,'/') . '/';
$instance->_options['cache_dir'] = $path;

return $instance;
}

/**
* 设置缓存文件前缀
*
* @param srting $prefix
* @return self
*/
public static function setCachePrefix($prefix)
{
$instance  = self::getInstance();
$instance->_options['file_name_prefix'] = $prefix;
return $instance;
}

/**
* 设置缓存存储类型
*
* @param int $mode
* @return self
*/
public static function setCacheMode($mode = 1)
{
$instance  = self::getInstance();
if($mode == 1)
{
$instance->_options['mode'] = 1;
}
else
{
$instance->_options['mode'] = 2;
}

return $instance;
}

/**
* 删除所有缓存
* @return boolean
*/
public static function flush()
{
$instance  = self::getInstance();
$glob = @glob($instance->_options['cache_dir'] . $instance->_options['file_name_prefix'] . '--*');

if(empty($glob))
{
return false;
}

foreach ($glob as $v)
{
$fileName = basename($v);
$id =  $instance->_fileNameToId($fileName);
$instance->delete($id);
}
return true;
}
}