<?php
// +----------------------------------------------------------------------
// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]
// +----------------------------------------------------------------------
// | Copyright (c) 2006-2014 http://thinkphp.cn All rights reserved.
// +----------------------------------------------------------------------
// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )
// +----------------------------------------------------------------------
// | Author: liu21st <liu21st@gmail.com>
// +----------------------------------------------------------------------
namespace Think\Cache\Driver;
use Think\Cache;
defined('THINK_PATH') or exit();
/**
 * 文件类型缓存类
 */
class File extends Cache {

 /**
 * 架构函数
 * @access public
 */
 public function __construct($options=array()) {
 if(!empty($options)) {
 $this->options = $options;
 }
 $this->options['temp'] = !empty($options['temp'])? $options['temp'] : C('DATA_CACHE_PATH');
 $this->options['prefix'] = isset($options['prefix'])? $options['prefix'] : C('DATA_CACHE_PREFIX');
 $this->options['expire'] = isset($options['expire'])? $options['expire'] : C('DATA_CACHE_TIME');
 $this->options['length'] = isset($options['length'])? $options['length'] : 0;
 if(substr($this->options['temp'], -1) != '/') $this->options['temp'] .= '/';
 $this->init();
 }

 /**
 * 初始化检查
 * @access private
 * @return boolean
 */
 private function init() {
 // 创建应用缓存目录
 if (!is_dir($this->options['temp'])) {
 mkdir($this->options['temp']);
 }
 }

 /**
 * 取得变量的存储文件名
 * @access private
 * @param string $name 缓存变量名
 * @return string
 */
 private function filename($name) {
 $name	=	md5(C('DATA_CACHE_KEY').$name);
 if(C('DATA_CACHE_SUBDIR')) {
 // 使用子目录
 $dir ='';
 for($i=0;$i<C('DATA_PATH_LEVEL');$i++) {
 $dir	.=	$name{$i}.'/';
 }
 if(!is_dir($this->options['temp'].$dir)) {
 mkdir($this->options['temp'].$dir,0755,true);
 }
 $filename	=	$dir.$this->options['prefix'].$name.'.php';
 }else{
 $filename	=	$this->options['prefix'].$name.'.php';
 }
 return $this->options['temp'].$filename;
 }

 /**
 * 读取缓存
 * @access public
 * @param string $name 缓存变量名
 * @return mixed
 */
 public function get($name) {
 $filename = $this->filename($name);
 if (!is_file($filename)) {
 return false;
 }
 N('cache_read',1);
 $content = file_get_contents($filename);
 if( false !== $content) {
 $expire = (int)substr($content,8, 12);
 if($expire != 0 && time() > filemtime($filename) + $expire) {
 //缓存过期删除缓存文件
 unlink($filename);
 return false;
 }
 if(C('DATA_CACHE_CHECK')) {//开启数据校验
 $check = substr($content,20, 32);
 $content = substr($content,52, -3);
 if($check != md5($content)) {//校验错误
 return false;
 }
 }else {
 	$content = substr($content,20, -3);
 }
 if(C('DATA_CACHE_COMPRESS') && function_exists('gzcompress')) {
 //启用数据压缩
 $content = gzuncompress($content);
 }
 $content = unserialize($content);
 return $content;
 }
 else {
 return false;
 }
 }

 /**
 * 写入缓存
 * @access public
 * @param string $name 缓存变量名
 * @param mixed $value 存储数据
 * @param int $expire 有效时间 0为永久
 * @return boolean
 */
 public function set($name,$value,$expire=null) {
 N('cache_write',1);
 if(is_null($expire)) {
 $expire = $this->options['expire'];
 }
 $filename = $this->filename($name);
 $data = serialize($value);
 if( C('DATA_CACHE_COMPRESS') && function_exists('gzcompress')) {
 //数据压缩
 $data = gzcompress($data,3);
 }
 if(C('DATA_CACHE_CHECK')) {//开启数据校验
 $check = md5($data);
 }else {
 $check = '';
 }
 $data = "<?php\n//".sprintf('%012d',$expire).$check.$data."\n?>";
 $result = file_put_contents($filename,$data);
 if($result) {
 if($this->options['length']>0) {
 // 记录缓存队列
 $this->queue($name);
 }
 clearstatcache();
 return true;
 }else {
 return false;
 }
 }

 /**
 * 删除缓存
 * @access public
 * @param string $name 缓存变量名
 * @return boolean
 */
 public function rm($name) {
 return unlink($this->filename($name));
 }

 /**
 * 清除缓存
 * @access public
 * @param string $name 缓存变量名
 * @return boolean
 */
 public function clear() {
 $path = $this->options['temp'];
 $files = scandir($path);
 if($files){
 foreach($files as $file){
 if ($file != '.' && $file != '..' && is_dir($path.$file) ){
 array_map( 'unlink', glob( $path.$file.'/*.*' ) );
 }elseif(is_file($path.$file)){
 unlink( $path . $file );
 }
 }
 return true;
 }
 return false;
 }
}