gecko-dev/dom/presentation/PresentationDataChannelSessionTransport.jsm

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

"use strict";

const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");

// Bug 1228209 - plan to remove this eventually
function log(aMsg) {
  // dump("-*- PresentationDataChannelSessionTransport.js : " + aMsg + "\n");
}

const PRESENTATIONTRANSPORT_CID = Components.ID(
  "{dd2bbf2f-3399-4389-8f5f-d382afb8b2d6}"
);
const PRESENTATIONTRANSPORT_CONTRACTID =
  "mozilla.org/presentation/datachanneltransport;1";

const PRESENTATIONTRANSPORTBUILDER_CID = Components.ID(
  "{215b2f62-46e2-4004-a3d1-6858e56c20f3}"
);
const PRESENTATIONTRANSPORTBUILDER_CONTRACTID =
  "mozilla.org/presentation/datachanneltransportbuilder;1";

function PresentationDataChannelDescription(aDataChannelSDP) {
  this._dataChannelSDP = JSON.stringify(aDataChannelSDP);
}

PresentationDataChannelDescription.prototype = {
  QueryInterface: ChromeUtils.generateQI([
    Ci.nsIPresentationChannelDescription,
  ]),
  get type() {
    return Ci.nsIPresentationChannelDescription.TYPE_DATACHANNEL;
  },
  get tcpAddress() {
    return null;
  },
  get tcpPort() {
    return null;
  },
  get dataChannelSDP() {
    return this._dataChannelSDP;
  },
};

function PresentationTransportBuilder() {
  log("PresentationTransportBuilder construct");
  this._isControlChannelNeeded = true;
}

PresentationTransportBuilder.prototype = {
  classID: PRESENTATIONTRANSPORTBUILDER_CID,
  contractID: PRESENTATIONTRANSPORTBUILDER_CONTRACTID,
  QueryInterface: ChromeUtils.generateQI([
    Ci.nsIPresentationSessionTransportBuilder,
    Ci.nsIPresentationDataChannelSessionTransportBuilder,
    Ci.nsITimerCallback,
  ]),

  buildDataChannelTransport(aRole, aWindow, aListener) {
    if (!aRole || !aWindow || !aListener) {
      log("buildDataChannelTransport with illegal parameters");
      throw Cr.NS_ERROR_ILLEGAL_VALUE;
    }

    if (this._window) {
      log("buildDataChannelTransport has started.");
      throw Cr.NS_ERROR_UNEXPECTED;
    }

    log("buildDataChannelTransport with role " + aRole);
    this._role = aRole;
    this._window = aWindow;
    this._listener = aListener.QueryInterface(
      Ci.nsIPresentationSessionTransportBuilderListener
    );

    // TODO bug 1227053 set iceServers from |nsIPresentationDevice|
    this._peerConnection = new this._window.RTCPeerConnection();

    // |this._listener == null| will throw since the control channel is
    // abnormally closed.
    this._peerConnection.onicecandidate = aEvent =>
      aEvent.candidate &&
      this._listener.sendIceCandidate(JSON.stringify(aEvent.candidate));

    this._peerConnection.onnegotiationneeded = () => {
      log("onnegotiationneeded with role " + this._role);
      if (!this._peerConnection) {
        log("ignoring negotiationneeded without PeerConnection");
        return;
      }
      this._peerConnection
        .createOffer()
        .then(aOffer => this._peerConnection.setLocalDescription(aOffer))
        .then(() =>
          this._listener.sendOffer(
            new PresentationDataChannelDescription(
              this._peerConnection.localDescription
            )
          )
        )
        .catch(e => this._reportError(e));
    };

    switch (this._role) {
      case Ci.nsIPresentationService.ROLE_CONTROLLER:
        this._dataChannel = this._peerConnection.createDataChannel(
          "presentationAPI"
        );
        this._setDataChannel();
        break;

      case Ci.nsIPresentationService.ROLE_RECEIVER:
        this._peerConnection.ondatachannel = aEvent => {
          this._dataChannel = aEvent.channel;
          // Ensure the binaryType of dataChannel is blob.
          this._dataChannel.binaryType = "blob";
          this._setDataChannel();
        };
        break;
      default:
        throw Cr.NS_ERROR_ILLEGAL_VALUE;
    }

    // TODO bug 1228235 we should have a way to let device providers customize
    // the time-out duration.
    let timeout = Services.prefs.getIntPref(
      "presentation.receiver.loading.timeout",
      10000
    );

    // The timer is to check if the negotiation finishes on time.
    this._timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
    this._timer.initWithCallback(this, timeout, this._timer.TYPE_ONE_SHOT);
  },

  notify() {
    if (!this._sessionTransport) {
      this._cleanup(Cr.NS_ERROR_NET_TIMEOUT);
    }
  },

  _reportError(aError) {
    log("report Error " + aError.name + ":" + aError.message);
    this._cleanup(Cr.NS_ERROR_FAILURE);
  },

  _setDataChannel() {
    this._dataChannel.onopen = () => {
      log("data channel is open, notify the listener, role " + this._role);

      // Handoff the ownership of _peerConnection and _dataChannel to
      // _sessionTransport
      this._sessionTransport = new PresentationTransport();
      this._sessionTransport.init(
        this._peerConnection,
        this._dataChannel,
        this._window
      );
      this._peerConnection.onicecandidate = null;
      this._peerConnection.onnegotiationneeded = null;
      this._peerConnection = this._dataChannel = null;

      this._listener.onSessionTransport(this._sessionTransport);
      this._sessionTransport.callback.notifyTransportReady();

      this._cleanup(Cr.NS_OK);
    };

    this._dataChannel.onerror = aError => {
      log("data channel onerror " + aError.name + ":" + aError.message);
      this._cleanup(Cr.NS_ERROR_FAILURE);
    };
  },

  _cleanup(aReason) {
    if (aReason != Cr.NS_OK) {
      this._listener.onError(aReason);
    }

    if (this._dataChannel) {
      this._dataChannel.close();
      this._dataChannel = null;
    }

    if (this._peerConnection) {
      this._peerConnection.close();
      this._peerConnection = null;
    }

    this._role = null;
    this._window = null;

    this._listener = null;
    this._sessionTransport = null;

    if (this._timer) {
      this._timer.cancel();
      this._timer = null;
    }
  },

  // nsIPresentationControlChannelListener
  onOffer(aOffer) {
    if (
      this._role !== Ci.nsIPresentationService.ROLE_RECEIVER ||
      this._sessionTransport
    ) {
      log("onOffer status error");
      this._cleanup(Cr.NS_ERROR_FAILURE);
    }

    log("onOffer: " + aOffer.dataChannelSDP + " with role " + this._role);

    let offer = new this._window.RTCSessionDescription(
      JSON.parse(aOffer.dataChannelSDP)
    );

    this._peerConnection
      .setRemoteDescription(offer)
      .then(
        () =>
          this._peerConnection.signalingState == "stable" ||
          this._peerConnection.createAnswer()
      )
      .then(aAnswer => this._peerConnection.setLocalDescription(aAnswer))
      .then(() => {
        this._isControlChannelNeeded = false;
        this._listener.sendAnswer(
          new PresentationDataChannelDescription(
            this._peerConnection.localDescription
          )
        );
      })
      .catch(e => this._reportError(e));
  },

  onAnswer(aAnswer) {
    if (
      this._role !== Ci.nsIPresentationService.ROLE_CONTROLLER ||
      this._sessionTransport
    ) {
      log("onAnswer status error");
      this._cleanup(Cr.NS_ERROR_FAILURE);
    }

    log("onAnswer: " + aAnswer.dataChannelSDP + " with role " + this._role);

    let answer = new this._window.RTCSessionDescription(
      JSON.parse(aAnswer.dataChannelSDP)
    );

    this._peerConnection
      .setRemoteDescription(answer)
      .catch(e => this._reportError(e));
    this._isControlChannelNeeded = false;
  },

  onIceCandidate(aCandidate) {
    log("onIceCandidate: " + aCandidate + " with role " + this._role);
    if (!this._window || !this._peerConnection) {
      log("ignoring ICE candidate after connection");
      return;
    }
    let candidate = new this._window.RTCIceCandidate(JSON.parse(aCandidate));
    this._peerConnection
      .addIceCandidate(candidate)
      .catch(e => this._reportError(e));
  },

  notifyDisconnected(aReason) {
    log("notifyDisconnected reason: " + aReason);

    if (aReason != Cr.NS_OK) {
      this._cleanup(aReason);
    } else if (this._isControlChannelNeeded) {
      this._cleanup(Cr.NS_ERROR_FAILURE);
    }
  },
};

function PresentationTransport() {
  this._messageQueue = [];
  this._closeReason = Cr.NS_OK;
}

PresentationTransport.prototype = {
  classID: PRESENTATIONTRANSPORT_CID,
  contractID: PRESENTATIONTRANSPORT_CONTRACTID,
  QueryInterface: ChromeUtils.generateQI([Ci.nsIPresentationSessionTransport]),

  init(aPeerConnection, aDataChannel, aWindow) {
    log("initWithDataChannel");
    this._enableDataNotification = false;
    this._dataChannel = aDataChannel;
    this._peerConnection = aPeerConnection;
    this._window = aWindow;

    this._dataChannel.onopen = () => {
      log("data channel reopen. Should never touch here");
    };

    this._dataChannel.onclose = () => {
      log("data channel onclose");
      if (this._callback) {
        this._callback.notifyTransportClosed(this._closeReason);
      }
      this._cleanup();
    };

    this._dataChannel.onmessage = aEvent => {
      log("data channel onmessage " + aEvent.data);

      if (!this._enableDataNotification || !this._callback) {
        log("queue message");
        this._messageQueue.push(aEvent.data);
        return;
      }
      this._doNotifyData(aEvent.data);
    };

    this._dataChannel.onerror = aError => {
      log("data channel onerror " + aError.name + ":" + aError.message);
      if (this._callback) {
        this._callback.notifyTransportClosed(Cr.NS_ERROR_FAILURE);
      }
      this._cleanup();
    };
  },

  // nsIPresentationTransport
  get selfAddress() {
    throw Cr.NS_ERROR_NOT_AVAILABLE;
  },

  get callback() {
    return this._callback;
  },

  set callback(aCallback) {
    this._callback = aCallback;
  },

  send(aData) {
    log("send " + aData);
    this._dataChannel.send(aData);
  },

  sendBinaryMsg(aData) {
    log("sendBinaryMsg");

    let array = new Uint8Array(aData.length);
    for (let i = 0; i < aData.length; i++) {
      array[i] = aData.charCodeAt(i);
    }

    this._dataChannel.send(array);
  },

  sendBlob(aBlob) {
    log("sendBlob");

    this._dataChannel.send(aBlob);
  },

  enableDataNotification() {
    log("enableDataNotification");
    if (this._enableDataNotification) {
      return;
    }

    if (!this._callback) {
      throw Cr.NS_ERROR_NOT_AVAILABLE;
    }

    this._enableDataNotification = true;

    this._messageQueue.forEach(aData => this._doNotifyData(aData));
    this._messageQueue = [];
  },

  close(aReason) {
    this._closeReason = aReason;

    this._dataChannel.close();
  },

  _cleanup() {
    this._dataChannel = null;

    if (this._peerConnection) {
      this._peerConnection.close();
      this._peerConnection = null;
    }
    this._callback = null;
    this._messageQueue = [];
    this._window = null;
  },

  _doNotifyData(aData) {
    if (!this._callback) {
      throw Cr.NS_ERROR_NOT_AVAILABLE;
    }

    if (aData instanceof this._window.Blob) {
      let reader = new this._window.FileReader();
      reader.addEventListener("load", aEvent => {
        this._callback.notifyData(aEvent.target.result, true);
      });
      reader.readAsBinaryString(aData);
    } else {
      this._callback.notifyData(aData, false);
    }
  },
};

var EXPORTED_SYMBOLS = [
  "PresentationTransportBuilder",
  "PresentationTransport",
];