PHP file download class that supports breakpoint resumption (source code attached)

/**PHP download class, supports breakpoint resume
* Date: 2013-06-30
* Author: fdipzone
* Ver: 1.0
* edit: ww.jbxue.com
* Func:
* download: Download file
* setSpeed : Set the download speed
* getRange: Get the Range in the header
*/

class FileDownload{ // class start

    private $_speed = 512;   // 下载速度

    /**Download
 * @param String $file The path of the file to be downloaded
 * @param String $name The file name, if it is empty, it will be the same as the downloaded file name
 * @param boolean $reload Whether to enable breakpoint resumption
*/
    public function download($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 '';
        }
    }

    /**Set download speed
 * @param int $speed
*/
    public function setSpeed($speed){
        if(is_numeric($speed) && $speed>16 && $speed<4096){
            $this->_speed = $speed;
        }
    }

    /**Get header range information
 * @param int $file_size file size
 * @return Array
*/
    private function getRange($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

?>

2，演示示例 demo.php

require('FileDownload.class.php');
$file = 'book.zip';
$name = time().'.zip';
$obj = new FileDownload();
$flag = $obj->download($file, $name);
//$flag = $obj->download($file, $name, true); // 断点续传

if(!$flag){
    echo 'file not exists';
}

?>

断点续传测试方法: 使用linux wget命令去测试下载, wget -c -O file http://xxx

1，先关闭断点续传

$flag = $obj->download($file, $name);

Use wget command to test breakpoint resumption:

root@jbxue:~/Downloads$ wget -O test.rar http://demo.fdipzone.com/demo.php
--2013-06-30 16:52:44-- http: //demo.fdipzone.com/demo.php
Resolving host demo.fdipzone.com... 127.0.0.1
Connecting demo.fdipzone.com|127.0.0.1|:80... Connected.
HTTP request sent, waiting for response... 200 OK
Length: 10445120 (10.0M) [application/octet-stream]
Saving to: “test.rar”
30% [======== =====================> ] 3,146,580 513K/s Estimated time 14s
^C
root@jbxue:~/Downloads$ wget -c -O test. rar http://demo.fdipzone.com/demo.php
--2013-06-30 16:52:57-- http://demo.fdipzone.com/demo.php
Resolving host demo.fdipzone. com... 127.0.0.1
Connecting demo.fdipzone.com|127.0.0.1|:80... Connected.
HTTP request sent, waiting for response... 200 OK
Length: 10445120 (10.0M) [application/octet-stream]
Saving to: “test.rar”
30% [======== =====================> ] 3,146,580 515K/s Estimated time 14s
^C

You can see it with wget -c The download cannot be resumed from a interrupted point.

2. Enable breakpoint resumption

$flag = $obj->download($file, $name, true);

Use the wget command to test the resume function.

root@jbxue:~/Downloads$ wget -O test.rar http://demo.fdipzone.com/demo.php
--2013-06-30 16:53:19-- http: //demo.fdipzone.com/demo.php
Resolving host demo.fdipzone.com... 127.0.0.1
Connecting demo.fdipzone.com|127.0.0.1|:80... Connected.
HTTP request sent, waiting for response... 200 OK
Length: 10445120 (10.0M) [application/octet-stream]
Saving to: “test.rar”

20% [====== ============> ] 2,097,720 516K/s Estimated time 16s
^C
root@jbxue:~/Downloads$ wget -c -O test.rar http://demo.fdipzone. com/demo.php
--2013-06-30 16:53:31-- http://demo.fdipzone.com/demo.php
Resolving host demo.fdipzone.com... 127.0.0.1
Resolving Connect demo.fdipzone.com|127.0.0.1|:80... Connected.
HTTP request sent, waiting for response... 206 Partial Content
Length: 10445121 (10.0M), 7822971 (7.5M) Bytes remaining [application/octet-stream]
Saving to: “test.rar”

100%[++++++++++++++++++++++++====================== =========>] 10,445,121 543K/s took 14s

2013-06-30 16:53:45 (543 KB/s) - Saved "test.rar" [10445121/10445121] )

You can see that the download will start from the breakpoint position (%20).

Attached, the source code download address of the PHP file download class (supports breakpoint resume download)