Support for multirange requests for media FS#1630

Ignore-this: 50de569608231b910a62327d2f3af1de

This patch moves all HTTP sending related functions to inc/httputils.php

Handling of range requests was rewritten completely to support mutirange
requests. This should fix problems with Adobe Reader but needs testing.

darcs-hash:20090313190247-7ad00-e6ec1f81acb9f7ac651357dd034c2689aea6868d.gz

1 files changed, 198 insertions, 0 deletions

diff --git a/inc/httputils.php b/inc/httputils.php
new file mode 100644
index 000000000..271b8272f
--- /dev/null
+++ b/inc/httputils.php
@@ -0,0 +1,198 @@
+<?php
+/**
+ * Utilities for handling HTTP related tasks
+ *
+ * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
+ * @author     Andreas Gohr <andi@splitbrain.org>
+ */
+
+define('HTTP_MULTIPART_BOUNDARY','D0KuW1K1B0uNDARY');
+define('HTTP_HEADER_LF',"\r\n");
+define('HTTP_CHUNK_SIZE',16*1024);
+
+/**
+ * Checks and sets HTTP headers for conditional HTTP requests
+ *
+ * @author   Simon Willison <swillison@gmail.com>
+ * @link     http://simon.incutio.com/archive/2003/04/23/conditionalGet
+ * @param    timestamp $timestamp lastmodified time of the cache file
+ * @returns  void or exits with previously header() commands executed
+ */
+function http_conditionalRequest($timestamp){
+  // A PHP implementation of conditional get, see
+  //   http://fishbowl.pastiche.org/archives/001132.html
+  $last_modified = substr(gmdate('r', $timestamp), 0, -5).'GMT';
+  $etag = '"'.md5($last_modified).'"';
+  // Send the headers
+  header("Last-Modified: $last_modified");
+  header("ETag: $etag");
+  // See if the client has provided the required headers
+  if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE'])){
+    $if_modified_since = stripslashes($_SERVER['HTTP_IF_MODIFIED_SINCE']);
+  }else{
+    $if_modified_since = false;
+  }
+
+  if (isset($_SERVER['HTTP_IF_NONE_MATCH'])){
+    $if_none_match = stripslashes($_SERVER['HTTP_IF_NONE_MATCH']);
+  }else{
+    $if_none_match = false;
+  }
+
+  if (!$if_modified_since && !$if_none_match){
+    return;
+  }
+
+  // At least one of the headers is there - check them
+  if ($if_none_match && $if_none_match != $etag) {
+    return; // etag is there but doesn't match
+  }
+
+  if ($if_modified_since && $if_modified_since != $last_modified) {
+    return; // if-modified-since is there but doesn't match
+  }
+
+  // Nothing has changed since their last request - serve a 304 and exit
+  header('HTTP/1.0 304 Not Modified');
+
+  // don't produce output, even if compression is on
+  ob_end_clean();
+  exit;
+}
+
+/**
+ * Let the webserver send the given file vi x-sendfile method
+ *
+ * @author Chris Smith <chris.eureka@jalakai.co.uk>
+ * @returns  void or exits with previously header() commands executed
+ */
+function http_sendfile($file) {
+  global $conf;
+
+  //use x-sendfile header to pass the delivery to compatible webservers
+  if($conf['xsendfile'] == 1){
+    header("X-LIGHTTPD-send-file: $file");
+    ob_end_clean();
+    exit;
+  }elseif($conf['xsendfile'] == 2){
+    header("X-Sendfile: $file");
+    ob_end_clean();
+    exit;
+  }elseif($conf['xsendfile'] == 3){
+    header("X-Accel-Redirect: $file");
+    ob_end_clean();
+    exit;
+  }
+
+  return false;
+}
+
+/**
+ * Send file contents supporting rangeRequests
+ *
+ * This function exits the running script
+ *
+ * @param ressource $fh - file handle for an already open file
+ * @param int $size     - size of the whole file
+ * @param int $mime     - MIME type of the file
+ *
+ * @author Andreas Gohr <andi@splitbrain.org>
+ */
+function http_rangeRequest($fh,$size,$mime){
+    $ranges  = array();
+    $isrange = false;
+
+    header('Accept-Ranges: bytes');
+
+    if(!isset($_SERVER['HTTP_RANGE'])){
+        // no range requested - send the whole file
+        $ranges[] = array(0,$size,$size);
+    }else{
+        $t = explode('=', $_SERVER['HTTP_RANGE']);
+        if (!$t[0]=='bytes') {
+            // we only understand byte ranges - send the whole file
+            $ranges[] = array(0,$size,$size);
+        }else{
+            $isrange = true;
+            // handle multiple ranges
+            $r = explode(',',$t[1]);
+            foreach($r as $x){
+                $p = explode('-', $x);
+                $start = (int)$p[0];
+                $end   = (int)$p[1];
+                if (!$end) $end = $size - 1;
+                if ($start > $end || $start > $size || $end > $size){
+                    header('HTTP/1.1 416 Requested Range Not Satisfiable');
+                    print 'Bad Range Request!';
+                    exit;
+                }
+                $len = $end - $start + 1;
+                $ranges[] = array($start,$end,$len);
+            }
+        }
+    }
+    $parts = count($ranges);
+
+    // now send the type and length headers
+    if(!$isrange){
+        header("Content-Type: $mime",true);
+    }else{
+        header('HTTP/1.1 206 Partial Content');
+        if($parts == 1){
+            header("Content-Type: $mime",true);
+        }else{
+            header('Content-Type: multipart/byteranges; boundary='.HTTP_MULTIPART_BOUNDARY,true);
+        }
+    }
+
+    // send all ranges
+    for($i=0; $i<$parts; $i++){
+        list($start,$end,$len) = $ranges[$i];
+
+        // multipart or normal headers
+        if($parts > 1){
+            echo HTTP_HEADER_LF.'--'.HTTP_MULTIPART_BOUNDARY.HTTP_HEADER_LF;
+            echo "Content-Type: $mime".HTTP_HEADER_LF;
+            echo "Content-Range: bytes $start-$end/$size".HTTP_HEADER_LF;
+        }else{
+            header("Content-Length: $len");
+            if($isrange){
+                header("Content-Range: bytes $start-$end/$size");
+            }
+        }
+
+        // send file content
+        fseek($fh,$start); //seek to start of range
+        $chunk = ($len > HTTP_CHUNK_SIZE) ? HTTP_CHUNK_SIZE : $len;
+        while (!feof($fh) && $chunk > 0) {
+          @set_time_limit(30); // large files can take a lot of time
+          print fread($fh, $chunk);
+          flush();
+          $len -= $chunk;
+          $chunk = ($len > HTTP_CHUNK_SIZE) ? HTTP_CHUNK_SIZE : $len;
+        }
+    }
+    if($parts > 1){
+        echo HTTP_HEADER_LF.'--'.HTTP_MULTIPART_BOUNDARY.'--'.HTTP_HEADER_LF;
+    }
+
+    // everything should be done here, exit
+    exit;
+}
+
+/**
+ * Check for a gzipped version and create if necessary
+ *
+ * return true if there exists a gzip version of the uncompressed file
+ * (samepath/samefilename.sameext.gz) created after the uncompressed file
+ *
+ * @author Chris Smith <chris.eureka@jalakai.co.uk>
+ */
+function http_gzip_valid($uncompressed_file) {
+    $gzip = $uncompressed_file.'.gz';
+    if (filemtime($gzip) < filemtime($uncompressed_file)) {    // filemtime returns false (0) if file doesn't exist
+        return copy($uncompressed_file, 'compress.zlib://'.$gzip);
+    }
+
+    return true;
+}