gistfile1.txt

var webrtc = require('..');

var RTCPeerConnection     = webrtc.RTCPeerConnection;
var RTCSessionDescription = webrtc.RTCSessionDescription;
var RTCIceCandidate       = webrtc.RTCIceCandidate;

var pc1 = new RTCPeerConnection();
var pc2 = new RTCPeerConnection();

pc1.onicecandidate = function(candidate) {
  if(!candidate.candidate) return;
  pc2.addIceCandidate(candidate.candidate);
}

pc2.onicecandidate = function(candidate) {
  if(!candidate.candidate) return;
  pc1.addIceCandidate(candidate.candidate);
}

function handle_error(error)
{
  throw error;
}

function toUint8Array(buffer, size) {
    var ab = new ArrayBuffer(size);
    var view = new Uint8Array(ab);
    for (var i = 0; i < size; ++i) {
        view[i] = buffer[i];
    }
    return ab;
}

function toBuffer(ab) {
    var buffer = new Buffer(ab.byteLength);
    var view = new Uint8Array(ab);
    for (var i = 0; i < buffer.length; ++i) {
        buffer[i] = view[i];
    }
    return buffer;
}

var timestampStart;
var fs = require("fs");
var stream = require("stream");
var chunksize = 1024;
//target file
var writeStream = fs.createWriteStream('/Users/browserstack/Downloads/test.zip');
//source file
var fileName = "/Users/browserstack/Downloads/nwjs-v0.12.1-osx-x64.zip";
var filesize = 0, bitrate_job, max_rate = 0;
function create_data_channels() {
  var dc1 = pc1.createDataChannel('test');
  dc1.binaryType = 'arraybuffer';
  dc1.onopen = function() {
    fs.stat(fileName, function(error, stats) {
      fs.open(fileName, "r", function(error, fd) {
        var startIndex = 0;
        filesize = stats.size;
        var readSize = chunksize < stats.size ? chunksize : filesize;
        console.log('file:', fileName,'size:', filesize / 1000, 'KB', 'chunksize:', chunksize);
        var buffer = new Buffer(chunksize);
        var read = function(){
          if (startIndex >= filesize){
            return;
          }
          fs.read(fd, buffer, 0, readSize, startIndex, function(error, bytesRead, buf) {
            dc1.send(toUint8Array(buf, bytesRead));
            startIndex += bytesRead;
            if(readSize + startIndex > stats.size){
              readSize = stats.size - startIndex;
            }
            read();
          });
        }
        read();
      });
    });
    
    dc1.onmessage = function(event) {

    }
  }

  var dc2;
  pc2.ondatachannel = function(event) {
    dc2 = event.channel;
    dc2.onopen = function() {
      console.log("pc2: data channel open");
      var receivedSize = 0;

      var bufferStream = new stream.PassThrough();
      bufferStream.pipe(writeStream);
      dc2.onmessage = function(event) {
        receivedSize += event.data.byteLength;;
        bufferStream.push(toBuffer(event.data));
        if(filesize == receivedSize){
          done(displayStats);
        }
      }
      var oldsize = 0;
      timestampStart = (new Date()).getTime();
      var ts_old = timestampStart;
      var displayStats = function(){
        var rate = ((receivedSize - oldsize) / (new Date().getTime() - ts_old)).toFixed(2);

        var elapsedTime = new Date().getTime() - timestampStart;
        var avg_rate = (receivedSize / elapsedTime).toFixed(2);
        if(rate > max_rate){
          max_rate = rate;
        }
        process.stdout.write("\033[0Grx: current = "
          + rate + ' KB/s, ' + 
          'avg = ' + avg_rate + ' KB/s, ' + 
          'max = ' + max_rate + ' KB/s, ' +
          'time elapsed = ' + (elapsedTime /  1000) + ' seconds, ' +
          'recveived = ' + (receivedSize / 1000).toFixed(2) + ' KB'
        );
        ts_old = new Date().getTime();
        oldsize = receivedSize;
      }
      bitrate_job = setInterval(displayStats, 100);
    };
  }

  create_offer();
}

function create_offer() {
  console.log('pc1: create offer');
  pc1.createOffer(set_pc1_local_description, handle_error);
}

function set_pc1_local_description(desc) {
  console.log('pc1: set local description');
  pc1.setLocalDescription(
    new RTCSessionDescription(desc),
    set_pc2_remote_description.bind(undefined, desc),
    handle_error
  );
}

function set_pc2_remote_description(desc) {
  console.log('pc2: set remote description');
  pc2.setRemoteDescription(
    new RTCSessionDescription(desc),
    create_answer,
    handle_error
  );
}

function create_answer() {
  console.log('pc2: create answer');
  pc2.createAnswer(
    set_pc2_local_description,
    handle_error
  );
}

function set_pc2_local_description(desc) {
  console.log('pc2: set local description');
  pc2.setLocalDescription(
    new RTCSessionDescription(desc),
    set_pc1_remote_description.bind(undefined, desc),
    handle_error
  );
}

function set_pc1_remote_description(desc) {
  console.log('pc1: set remote description');
  pc1.setRemoteDescription(
    new RTCSessionDescription(desc),
    wait,
    handle_error
  );
}

function wait() {
  console.log('waiting');
}

function run() {
  create_data_channels();
}

function done(cb) {
  clearInterval(bitrate_job);
  cb();
  console.log('');
  writeStream.close();
  pc1.close();
  pc2.close();
}

run();