php断点续传之文件上传与文件下载

下载：

原理：

Http头的 Range、Content-Range()
未启用单点登录
Gerenal
Request URL: http://www.demotest.com/php/fileDownload/demo.php
Request Method: GET
Status Code: 200 OK
Remote Address: 127.0.0.1:80
Referrer Policy: no-referrer-when-downgrade
response响应头
HTTP/1.1 200 OK
Date: Thu, 02 May 2019 11:03:40 GMT
Server: Apache/2.4.23 (Win32) OpenSSL/1.0.2j PHP/7.2.14
X-Powered-By: PHP/7.2.14
cache-control: public
content-disposition: attachment; filename=1556795020.zip
Content-Length: 452368104
Keep-Alive: timeout=5, max=100
Connection: Keep-Alive
Content-Type: application/octet-stream
Request请求头
GET /php/fileDownload/demo.php HTTP/1.1
Host: www.demotest.com
Connection: keep-alive
Pragma: no-cache
Cache-Control: no-cache
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.9,en;q=0.8
启用单点登录

<?php
/** php下载类,支持断点续传
*   Date:   2013-06-30
*   Author: fdipzone
*   Ver:    1.0
*
*   Func:
*   public  download: 下载文件
*   public  setSpeed: 设置下载速度
*   private getRange: 获取header中Range
*/

class FileDownload{ // class start

    private $_speed = 512;   // 下载速度


    /** 下载
    * @param String  $file   要下载的文件路径
    * @param String  $name   文件名称,为空则与下载的文件名称一样
    * @param boolean $reload 是否开启断点续传
    */
    public function download($file, $name='', $reload=false){
        if(file_exists($file)){
            if($name==''){
                $name = basename($file);
            }

            $fp = fopen($file, 'rb');
            $file_size = filesize($file);
            $ranges = $this->getRange($file_size);

            header('cache-control:public');
            header('content-type:application/octet-stream');
            header('content-disposition:attachment; filename='.$name);

            if($reload && $ranges!=null){ // 使用续传
                header('HTTP/1.1 206 Partial Content');
                header('Accept-Ranges:bytes');
                
                // 剩余长度
                header(sprintf('content-length:%u',$ranges['end']-$ranges['start']));
                
                // range信息
                header(sprintf('content-range:bytes %s-%s/%s', $ranges['start'], $ranges['end'], $file_size));
                
                // fp指针跳到断点位置
                fseek($fp, sprintf('%u', $ranges['start']));
            }else{
                header('HTTP/1.1 200 OK');
                header('content-length:'.$file_size);
            }

            while(!feof($fp)){
                echo fread($fp, round($this->_speed*1024,0));
                ob_flush();
                //sleep(1); // 用于测试,减慢下载速度
            }

            ($fp!=null) && fclose($fp);

        }else{
            return '';
        }
    }


    /** 设置下载速度
    * @param int $speed
    */
    public function setSpeed($speed){
        if(is_numeric($speed) && $speed>16 && $speed<4096){
            $this->_speed = $speed;
        }
    }


    /** 获取header range信息
    * @param  int   $file_size 文件大小
    * @return Array
    */
    private function getRange($file_size){
        if(isset($_SERVER['HTTP_RANGE']) && !empty($_SERVER['HTTP_RANGE'])){
            $range = $_SERVER['HTTP_RANGE'];
            $range = preg_replace('/[s|,].*/', '', $range);
            $range = explode('-', substr($range, 6));
            if(count($range)<2){
                $range[1] = $file_size;
            }
            $range = array_combine(array('start','end'), $range);
            if(empty($range['start'])){
                $range['start'] = 0;
            }
            if(empty($range['end'])){
                $range['end'] = $file_size;
            }
            return $range;
        }
        return null;
    }

} // class end

?>

1. Request URL:
   http://www.demotest.com/php/fileDownload/demo.php
2. Request Method:
   GET
3. Status Code:
   200 OK
4. Remote Address:
   127.0.0.1:80
5. Referrer Policy:
   no-referrer-when-downgrade