1/* -*- Mode: JavaScript; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2/* vim: set ts=8 sts=2 et sw=2 tw=80: */ 3/* This Source Code Form is subject to the terms of the Mozilla Public 4 * License, v. 2.0. If a copy of the MPL was not distributed with this 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7/* dash_detect_stream_switch.sjs 8 * 9 * Parses requests for DASH manifests and ensures stream switching takes place 10 * by verifying the subsegments downloaded and the streams they belong to. 11 * If unexpected subsegments (byte ranges) are requested, the script will 12 * will respond with a 404. 13 */ 14 15var DEBUG = false; 16 17function parseQuery(request, key) { 18 var params = request.queryString.split('&'); 19 if (DEBUG) { 20 dump("DASH-SJS: request params = \"" + params + "\"\n"); 21 } 22 for (var j = 0; j < params.length; ++j) { 23 var p = params[j]; 24 if (p == key) 25 return true; 26 if (p.indexOf(key + "=") === 0) 27 return p.substring(key.length + 1); 28 if (p.indexOf("=") < 0 && key === "") 29 return p; 30 } 31 return false; 32} 33 34function handleRequest(request, response) 35{ 36 try { 37 var name = parseQuery(request, "name"); 38 var range = request.hasHeader("Range") ? request.getHeader("Range") 39 : undefined; 40 41 // Should not get request for 1st subsegment from 2nd stream, nor 2nd 42 // subsegment from 1st stream. 43 if (name == "dash-webm-video-320x180.webm" && range == "bytes=25514-32767" || 44 name == "dash-webm-video-428x240.webm" && range == "bytes=228-35852") 45 { 46 throw "Should not request " + name + " with byte-range " + range; 47 } else { 48 var rangeSplit = range.split("="); 49 if (rangeSplit.length != 2) { 50 throw "DASH-SJS: ERROR: invalid number of tokens (" + rangeSplit.length + 51 ") delimited by \'=\' in \'Range\' header."; 52 } 53 var offsets = rangeSplit[1].split("-"); 54 if (offsets.length != 2) { 55 throw "DASH-SJS: ERROR: invalid number of tokens (" + offsets.length + 56 ") delimited by \'-\' in \'Range\' header."; 57 } 58 var startOffset = parseInt(offsets[0]); 59 var endOffset = parseInt(offsets[1]); 60 var file = Components.classes["@mozilla.org/file/directory_service;1"]. 61 getService(Components.interfaces.nsIProperties). 62 get("CurWorkD", Components.interfaces.nsIFile); 63 var fis = Components.classes['@mozilla.org/network/file-input-stream;1']. 64 createInstance(Components.interfaces.nsIFileInputStream); 65 var bis = Components.classes["@mozilla.org/binaryinputstream;1"]. 66 createInstance(Components.interfaces.nsIBinaryInputStream); 67 68 var paths = "tests/dom/media/test/" + name; 69 var split = paths.split("/"); 70 for (var i = 0; i < split.length; ++i) { 71 file.append(split[i]); 72 } 73 74 fis.init(file, -1, -1, false); 75 // Exception: start offset should be within file bounds. 76 if (startOffset > file.fileSize) { 77 throw "Starting offset [" + startOffset + "] is after end of file [" + 78 file.fileSize + "]."; 79 } 80 // End offset may be too large in the MPD. Real world HTTP servers just 81 // return what data they can; do the same here - reduce the end offset. 82 if (endOffset >= file.fileSize) { 83 if (DEBUG) { 84 dump("DASH-SJS: reducing endOffset [" + endOffset + "] to fileSize [" + 85 (file.fileSize-1) + "]\n"); 86 } 87 endOffset = file.fileSize-1; 88 } 89 fis.seek(Components.interfaces.nsISeekableStream.NS_SEEK_SET, startOffset); 90 bis.setInputStream(fis); 91 92 var byteLengthToRead = endOffset + 1 - startOffset; 93 var totalBytesExpected = byteLengthToRead + startOffset; 94 if (DEBUG) { 95 dump("DASH-SJS: byteLengthToRead = " + byteLengthToRead + 96 " byteLengthToRead+startOffset = " + totalBytesExpected + 97 " fileSize = " + file.fileSize + "\n"); 98 } 99 100 var bytes = bis.readBytes(byteLengthToRead); 101 response.setStatusLine(request.httpVersion, 206, "Partial Content"); 102 response.setHeader("Content-Length", ""+bytes.length, false); 103 response.setHeader("Content-Type", "application/dash+xml", false); 104 var contentRange = "bytes " + startOffset + "-" + endOffset + "/" + 105 file.fileSize; 106 response.setHeader("Content-Range", contentRange, false); 107 response.write(bytes, bytes.length); 108 bis.close(); 109 } 110 } catch (e) { 111 dump ("DASH-SJS-ERROR: " + e + "\n"); 112 response.setStatusLine(request.httpVersion, 404, "Not found"); 113 } 114} 115