- add an "Download big file" example

diff --git a/docs/examples/tutorial.txt b/docs/examples/tutorial.txt
index fbe9f210758fc659d7bdec23bbd57f5fcf083dd6..d2a8cf10c03e95ac005a06967bdc509a86f37e1e 100644 (file)
--- 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;
+       }
+}
+?>