PHP Classes

File: class.httpdownload.php

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File: class.httpdownload.php
Role: Class source
Content type: text/plain
Description: Class
Class: HTTP Download
Server files for downloading with resume support
Author: By
Last change: Fix small problem with seek_start
Date: 18 years ago
Size: 7,905 bytes
 

Contents

Class file image Download
<?

/**
 @author Nguyen Quoc Bao <quocbao.coder@gmail.com>
 @version 1.3
 @desc A simple object for processing download operation , support section downloading
 Please send me an email if you find some bug or it doesn't work with download manager.
 I've tested it with
     - Reget
     - FDM
     - FlashGet
     - GetRight
     - DAP
    
 @copyright It's free as long as you keep this header .
 @example
 
 1: File Download
     $object = new downloader;
     $object->set_byfile($filename); //Download from a file
     $object->use_resume = true; //Enable Resume Mode
     $object->download(); //Download File
    
 2: Data Download
  $object = new downloader;
     $object->set_bydata($data); //Download from php data
     $object->use_resume = true; //Enable Resume Mode
     $object->set_filename($filename); //Set download name
     $object->set_mime($mime); //File MIME (Default: application/otect-stream)
     $object->download(); //Download File
    
     3: Manual Download
     $object = new downloader;
     $object->set_filename($filename);
    $object->download_ex($size);
    //output your data here , remember to use $this->seek_start and $this->seek_end value :)
   
**/

class httpdownload {

    var
$data = null;
    var
$data_len = 0;
    var
$data_mod = 0;
    var
$data_type = 0;
    var
$data_section = 0; //section download
    /**
     * @var ObjectHandler
     **/
   
var $handler = array('auth' => null);
    var
$use_resume = true;
    var
$use_autoexit = false;
    var
$use_auth = false;
    var
$filename = null;
    var
$mime = null;
    var
$bufsize = 2048;
    var
$seek_start = 0;
    var
$seek_end = -1;
   
   
/**
     * Total bandwidth has been used for this download
     * @var int
     */
   
var $bandwidth = 0;
   
/**
     * Speed limit
     * @var float
     */
   
var $speed = 0;
   
   
/*-------------------
    | Download Function |
    -------------------*/
    /**
     * Check authentication and get seek position
     * @return bool
     **/
   
function initialize() {
        global
$HTTP_SERVER_VARS;
       
        if (
$this->use_auth) //use authentication
       
{
            if (!
$this->_auth()) //no authentication
           
{
               
header('WWW-Authenticate: Basic realm="Please enter your username and password"');
           
header('HTTP/1.0 401 Unauthorized');
           
header('status: 401 Unauthorized');
            if (
$this->use_autoexit) exit();
                return
false;
            }
        }
        if (
$this->mime == null) $this->mime = "application/octet-stream"; //default mime
       
       
if (isset($_SERVER['HTTP_RANGE']) || isset($HTTP_SERVER_VARS['HTTP_RANGE']))
        {
           
            if (isset(
$HTTP_SERVER_VARS['HTTP_RANGE'])) $seek_range = substr($HTTP_SERVER_VARS['HTTP_RANGE'] , strlen('bytes='));
            else
$seek_range = substr($_SERVER['HTTP_RANGE'] , strlen('bytes='));
           
           
$range = explode('-',$seek_range);
           
            if (
$range[0] > 0)
            {
               
$this->seek_start = intval($range[0]);
            }
           
            if (
$range[1] > 0) $this->seek_end = intval($range[1]);
            else
$this->seek_end = -1;
           
            if (!
$this->use_resume)
            {
               
$this->seek_start = 0;
               
               
//header("HTTP/1.0 404 Bad Request");
                //header("Status: 400 Bad Request");
               
                //exit;
               
                //return false;
           
}
            else
            {
               
$this->data_section = 1;
            }
           
        }
        else
        {
           
$this->seek_start = 0;
           
$this->seek_end = -1;
        }
       
        return
true;
    }
   
/**
     * Send download information header
     **/
   
function header($size,$seek_start=null,$seek_end=null) {
       
header('Content-type: ' . $this->mime);
       
header('Content-Disposition: attachment; filename="' . $this->filename . '"');
       
header('Last-Modified: ' . date('D, d M Y H:i:s \G\M\T' , $this->data_mod));
       
        if (
$this->data_section && $this->use_resume)
        {
           
header("HTTP/1.0 206 Partial Content");
           
header("Status: 206 Partial Content");
           
header('Accept-Ranges: bytes');
           
header("Content-Range: bytes $seek_start-$seek_end/$size");
           
header("Content-Length: " . ($seek_end - $seek_start + 1));
        }
        else
        {
           
header("Content-Length: $size");
        }
    }
   
    function
download_ex($size)
    {
        if (!
$this->initialize()) return false;
       
ignore_user_abort(true);
       
//Use seek end here
       
if ($this->seek_start > ($size - 1)) $this->seek_start = 0;
        if (
$this->seek_end <= 0) $this->seek_end = $size - 1;
       
$this->header($size,$seek,$this->seek_end);
       
$this->data_mod = time();
        return
true;
    }
   
   
/**
     * Start download
     * @return bool
     **/
   
function download() {
        if (!
$this->initialize()) return false;
       
       
$seek = $this->seek_start;
       
$speed = $this->speed;
       
$bufsize = $this->bufsize;
       
$packet = 1;
       
       
//do some clean up
       
@ob_end_clean();
       
$old_status = ignore_user_abort(true);
        @
set_time_limit(0);
       
$this->bandwidth = 0;
       
       
$size = $this->data_len;
       
        if (
$this->data_type == 0) //download from a file
       
{
           
           
$size = filesize($this->data);
            if (
$seek > ($size - 1)) $seek = 0;
            if (
$this->filename == null) $this->filename = basename($this->data);
           
           
$res = fopen($this->data,'rb');
            if (
$seek) fseek($res , $seek);
            if (
$this->seek_end < $seek) $this->seek_end = $size - 1;
           
           
$this->header($size,$seek,$this->seek_end); //always use the last seek
           
$size = $this->seek_end - $seek + 1;
           
            while (!(
connection_aborted() || connection_status() == 1) && $size > 0)
            {
                if (
$size < $bufsize)
                {
                    echo
fread($res , $size);
                   
$this->bandwidth += $size;
                }
                else
                {
                    echo
fread($res , $bufsize);
                   
$this->bandwidth += $bufsize;
                }
               
               
$size -= $bufsize;
               
flush();
               
                if (
$speed > 0 && ($this->bandwidth > $speed*$packet*1024))
                {
                   
sleep(1);
                   
$packet++;
                }
            }
           
fclose($res);
           
        }
       
        elseif (
$this->data_type == 1) //download from a string
       
{
            if (
$seek > ($size - 1)) $seek = 0;
            if (
$this->seek_end < $seek) $this->seek_end = $this->data_len - 1;
           
$this->data = substr($this->data , $seek , $this->seek_end - $seek + 1);
            if (
$this->filename == null) $this->filename = time();
           
$size = strlen($this->data);
           
$this->header($this->data_len,$seek,$this->seek_end);
            while (!
connection_aborted() && $size > 0) {
                if (
$size < $bufsize)
                {
                   
$this->bandwidth += $size;
                }
                else
                {
                   
$this->bandwidth += $bufsize;
                }
               
                echo
substr($this->data , 0 , $bufsize);
               
$this->data = substr($this->data , $bufsize);
               
               
$size -= $bufsize;
               
flush();
               
                if (
$speed > 0 && ($this->bandwidth > $speed*$packet*1024))
                {
                   
sleep(1);
                   
$packet++;
                }
            }
        } else if (
$this->data_type == 2) {
           
//just send a redirect header
           
header('location: ' . $this->data);
        }
       
        if (
$this->use_autoexit) exit();
       
       
//restore old status
       
ignore_user_abort($old_status);
       
set_time_limit(ini_get("max_execution_time"));
       
        return
true;
    }
   
    function
set_byfile($dir) {
        if (
is_readable($dir) && is_file($dir)) {
           
$this->data_len = 0;
           
$this->data = $dir;
           
$this->data_type = 0;
           
$this->data_mod = filemtime($dir);
            return
true;
        } else return
false;
    }
   
    function
set_bydata($data) {
        if (
$data == '') return false;
       
$this->data = $data;
       
$this->data_len = strlen($data);
       
$this->data_type = 1;
       
$this->data_mod = time();
        return
true;
    }
   
    function
set_byurl($data) {
       
$this->data = $data;
       
$this->data_len = 0;
       
$this->data_type = 2;
        return
true;
    }
   
    function
set_lastmodtime($time) {
       
$time = intval($time);
        if (
$time <= 0) $time = time();
       
$this->data_mod = $time;
    }
   
   
/**
     * Check authentication
     * @return bool
     **/
   
function _auth() {
        if (!isset(
$_SERVER['PHP_AUTH_USER'])) return false;
        if (isset(
$this->handler['auth']) && function_exists($this->handler['auth']))
        {
            return
$this->handler['auth']('auth' , $_SERVER['PHP_AUTH_USER'],$_SERVER['PHP_AUTH_PW']);
        }
        else return
true; //you must use a handler
   
}
   
}

?>