peer-emitter/write-stream.js

acknowledgeable events

var streams = require('stream');
var Writable = streams.Writable;
var PassThrough = streams.PassThrough;


module.exports = WriteStream;

function WriteStream(emitter, name) {
  var stream = new Writable({
    objectMode: true
  });

  var ackStream;
  var timeoutStream;

  stream._write = write;
  function write(data, _, cb) {

    function onAck(timeout) {
      if (!timeout && ackStream)
        ackStream.write(data);

      if (timeout && timeoutStream)
        timeoutStream.write(data);
    }

    if (timeoutStream)
      onAck.timeout = timeoutStream.timeout;

    if (ackStream || timeoutStream)
      emitter.emit(name, data, onAck);
    else
      emitter.emit(name, data);

    cb();
  }

  stream.AckStream = createAckStream;
  function createAckStream() {
    if (ackStream)
      throw Error('already created');

    return ackStream = new PassThrough({ objectMode: true });
  }

  stream.TimeoutStream = createTimeoutStream;
  function createTimeoutStream(options) {
    if (timeoutStream)
      throw Error('already created');
    
    timeoutStream = new PassThrough({ objectMode: true });
    timeoutStream.timeout = options && options.timeout;
    return timeoutStream;
  }

  return stream;
}