From c19bc275a7b59983992d018e5f74e7e4822c8035 Mon Sep 17 00:00:00 2001
From: Michael Wallner <mike@php.net>
Date: Tue, 6 Dec 2005 13:54:02 +0000
Subject: [PATCH] - add an "Download big file" example

---
 docs/examples/tutorial.txt | 126 +++++++++++++++++++++++++++++++++++++
 1 file changed, 126 insertions(+)

diff --git a/docs/examples/tutorial.txt b/docs/examples/tutorial.txt
index fbe9f21..d2a8cf1 100644
--- a/docs/examples/tutorial.txt
+++ b/docs/examples/tutorial.txt
@@ -341,4 +341,130 @@ class FeedAggregator
 }
 ?>
 
+- Download a big file
+
+<?php
+
+/*
+	$bigget = Bigget::url('http://www.example.com/big_file.bin');
+	$bigget->saveTo('file.bin');
+*/
+
+class BiggetRequest extends HttpRequest
+{
+	public $id;
+}
+
+class Bigget extends HttpRequestPool
+{
+	const SIZE = 1048576;
+	
+	private $url;
+	private $size;
+	private $count = 0;
+	private $files = array();
+	
+	static function url($url)
+	{
+		$head = new HttpRequest($url, HttpRequest::METH_HEAD);
+		$headers = $head->send()->getHeaders();
+		$head = null;
+		
+		if (!isset($headers['Accept-Ranges'])) {
+			throw new HttpExcpetion("Did not receive an Accept-Ranges header from HEAD $url");
+		}
+		if (!isset($headers['Content-Length'])) {
+			throw new HttpException("Did not receive a Content-Length header from HEAD $url");
+		}
+		
+		$bigget = new Bigget;
+		$bigget->url = $url;
+		$bigget->size = $headers['Content-Length'];
+		return $bigget;
+	}
+	
+	function saveTo($file)
+	{
+		$this->send();
+		if ($w = fopen($file, 'wb')) {
+			echo "\nCopying temp files to $file ...\n";
+			foreach (glob("bigget_????.tmp") as $tmp) {
+				echo "\t$tmp\n";
+				if ($r = fopen($tmp, 'rb')) {
+					stream_copy_to_stream($r, $w);
+					fclose($r);
+				}
+				unlink($tmp);
+			}
+			fclose($w);
+			echo "\nDone.\n";
+		}
+	}
+	
+	function send()
+	{
+		// use max 3 simultanous requests with a req size of 1MiB
+		while ($this->count < 3 && -1 != $offset = $this->getRangeOffset()) {
+			$this->attachNew($offset);
+		}
+		
+		while ($this->socketPerform()) {
+			if (!$this->socketSelect()) {
+				throw new HttpSocketException;
+			}
+		}
+	}
+	
+	private function attachNew($offset)
+	{
+		$stop = min($this->count * self::SIZE + self::SIZE, $this->size) - 1;
+		
+		echo "Attaching new request to get range: $offset-$stop\n";
+		
+		$req = new BiggetRequest(
+			$this->url,
+			HttpRequest::METH_GET,
+			array(
+				'headers' => array(
+					'Range' => "bytes=$offset-$stop"
+				)
+			)
+		);
+		$this->attach($req);
+		$req->id = $this->count++;
+	}
+	
+	private function getRangeOffset()
+	{
+		return ($this->size >= $start = $this->count * self::SIZE) ? $start : -1;
+	}
+	
+	protected function socketPerform()
+	{
+		try {
+			$rc = parent::socketPerform();
+		} catch (HttpRequestPoolException $x) {
+			foreach ($x->exceptionStack as $e) {
+				echo $e->getMessage(), "\n";
+			}
+		}
+		
+		foreach ($this->getFinishedRequests() as $r) {
+			$this->detach($r);
+			
+			if (206 != $rc = $r->getResponseCode()) {
+				throw new HttpException("Unexpected response code: $rc");
+			}
+			
+			file_put_contents(sprintf("bigget_%04d.tmp", $r->id), $r->getResponseBody());
+			
+			if (-1 != $offset = $this->getRangeOffset()) {
+				$this->attachNew($offset);
+			}
+		}
+		
+		return $rc;
+	}
+}
+?>
 
-- 
2.30.2