git.m6w6.name Git - m6w6/m6w6.github.io/blob - _posts/2005-12-06-peclhttp-nasty-bug-and-new-example.md

   1 ---
   2 title: PECL::HTTP - A nasty bug and a new example
   3 author: m6w6
   4 tags:
   5 - PHP
   6 ---
   7
   8 I just fixed a nasty bug which caused GZIP encoded files (speak tgz etc.) to
   9 be decoded. While it'll just eat **some** memory on a 200 response (besides
  10 that the body is not what one would expect), it'll eat all memory on 206
  11 (partial content) responses because the part is fed through zlib. I'll just
  12 need to revisit the HTTP RFC to check if checking for the "Vary" response
  13 header is the best bet before I drop the new release.
  14
  15 Ok, that's it about the bad news -- I also added a new example to the tutorial
  16 which shows how one could efficiently download big files. Using the example
  17 code would look like:
  18
  19 ```php
  20 $bigget = BigGet::url('http://example.com/big_file.bin');
  21 $bigGet->saveTo('big_file.bin');
  22
  23 class BigGetRequest extends HttpRequest
  24 {
  25     public $id;
  26 }
  27
  28 class BigGet extends HttpRequestPool
  29 {
  30     const SIZE = 1048576;
  31
  32     private $url;
  33     private $size;
  34     private $count = 0;
  35     private $files = array();
  36
  37     static function url($url)
  38     {
  39         $head = new HttpRequest($url, HttpRequest::METH_HEAD);
  40         $headers = $head->send()->getHeaders();
  41         $head = null;
  42
  43         if (!isset($headers['Accept-Ranges'])) {
  44             throw new HttpExcpetion("Did not receive an ".
  45                 "Accept-Ranges header from HEAD $url");
  46         }
  47         if (!isset($headers['Content-Length'])) {
  48             throw new HttpException("Did not receive a ".
  49                 "Content-Length header from HEAD $url");
  50         }
  51
  52         $bigget = new Bigget;
  53         $bigget->url = $url;
  54         $bigget->size = $headers['Content-Length'];
  55         return $bigget;
  56     }
  57
  58     function saveTo($file)
  59     {
  60         $this->send();
  61         if ($w = fopen($file, 'wb')) {
  62             echo "nCopying temp files to $file ...n";
  63             foreach (glob("bigget_????.tmp") as $tmp) {
  64                 echo "t$tmpn";
  65                 if ($r = fopen($tmp, 'rb')) {
  66                     stream_copy_to_stream($r, $w);
  67                     fclose($r);
  68                 }
  69                 unlink($tmp);
  70             }
  71             fclose($w);
  72             echo "nDone.n";
  73         }
  74     }
  75
  76     function send()
  77     {
  78         // use max 3 simultanous requests with a req size of 1MiB
  79         while ($this->count < 3 &&
  80                 -1 != $offset = $this->getRangeOffset()) {
  81             $this->attachNew($offset);
  82         }
  83
  84         while ($this->socketPerform()) {
  85             if (!$this->socketSelect()) {
  86                 throw new HttpSocketException;
  87             }
  88         }
  89     }
  90
  91     private function attachNew($offset)
  92     {
  93         $stop = min($this->count * self::SIZE + self::SIZE,
  94             $this->size) - 1;
  95
  96         echo "Attaching new request to get range: $offset-$stopn";
  97
  98         $req = new BigGetRequest(
  99             $this->url,
 100             HttpRequest::METH_GET,
 101             array(
 102                 'headers' => array(
 103                     'Range' => "bytes=$offset-$stop"
 104                 )
 105             )
 106         );
 107         $this->attach($req);
 108         $req->id = $this->count++;
 109     }
 110
 111     private function getRangeOffset()
 112     {
 113         return ($this->size >=
 114             $start = $this->count * self::SIZE) ? $start : -1;
 115     }
 116
 117     protected function socketPerform()
 118     {
 119         try {
 120             $rc = parent::socketPerform();
 121         } catch (HttpRequestPoolException $x) {
 122             foreach ($x->exceptionStack as $e) {
 123                 echo $e->getMessage(), "n";
 124             }
 125         }
 126
 127         foreach ($this->getFinishedRequests() as $r) {
 128             $this->detach($r);
 129
 130             if (206 != $rc = $r->getResponseCode()) {
 131                 throw new HttpException(
 132                     "Unexpected response code: $rc");
 133             }
 134
 135             file_put_contents(
 136                 sprintf("bigget_%04d.tmp", $r->id),
 137                 $r->getResponseBody());
 138
 139             if (-1 != $offset = $this->getRangeOffset()) {
 140                 $this->attachNew($offset);
 141             }
 142         }
 143
 144         return $rc;
 145     }
 146 }
 147 ```