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| /*global RTCPeerConnection*/
/*global RTCRtpSender*/
import cache from '../util/cache';
import * as Log from '../util/Log';
import Media from '../util/Media';
import * as DataSync from '../util/DataSync';
import {OPENED, CLOSING, CLOSED} from '../util/constants';
import 'core-js/fn/array/find';
const DtlsSrtpKeyAgreement = {DtlsSrtpKeyAgreement: true};
const sdpConstraints = receive => ({OfferToReceiveAudio: receive, OfferToReceiveVideo: receive});
/**
* ICE connection status : disconnected
* @constant
* @type {string}
*/
const ICE_CONNECTION_STATE_DISCONNECTED = 'disconnected';
/**
* ICE connection status : connected
* @constant
* @type {string}
*/
const ICE_CONNECTION_STATE_CONNECTED= 'connected';
/**
* ICE connection status : completed
* @constant
* @type {string}
*/
const ICE_CONNECTION_STATE_COMPLETED = 'completed';
/**
* ICE connection status : checking
* @constant
* @type {string}
*/
const ICE_CONNECTION_STATE_CHECKING = 'checking';
/**
* ICE connection status : closed
* @constant
* @type {string}
*/
const ICE_CONNECTION_STATE_CLOSED = 'closed';
/**
* ICE connection status : failed
* @constant
* @type {string}
*/
const ICE_CONNECTION_STATE_FAILED = 'failed';
/**
* ICE connection status : another status
* @constant
* @type {string}
*/
const ICE_CONNECTION_STATE_OTHER= 'other';
/**
* @ignore
*/
const _toJSON = o => o.toJSON && typeof o.toJSON === 'function' ? o.toJSON() : o;
/**
* The PeerConnection. A PeerConnection will only concern one MediaStream.
* @class PeerConnection
*/
export default class PeerConnection {
/**
* @access protected
* @param {string} stackId The WebRTC stack ID
* @param {string} streamId The Stream UID
* @param {string} remoteDevice The remote device's UID
* @param {boolean} publish Publish or Subscribe ?
*/
constructor(stackId, streamId, remoteDevice, publish) {
/**
* The stack identifier. Used to identify exchanges between 2 devices
* @type {string}
*/
this.stackId = stackId;
/**
* The stream id. (One stream per RTCPeerConnection)
* @type {string}
*/
this.streamId = streamId;
/**
* The remote device Id
* @type {string}
*/
this.remoteDevice = remoteDevice;
/**
* Path for local signalization
* @access private
* @type {string}
*/
this._localPath = `_/webrtc/${this.stackId}/${this.streamId}/${cache.device}`;
/**
* Path for local signalization
* @access private
* @type {string}
*/
this._remotePath = `_/webrtc/${this.stackId}/${this.streamId}/${this.remoteDevice}`;
/**
* Indicates if the PeerConnection has been established. (Useful for renegotiation).
* @type {boolean}
*/
this.negotiated = false;
/**
* The DOM element where the remote MediaStream will be displayed
* @type {Element}
* @protected
*/
this.node = null;
/**
* The DOM element containg the media element
* @type {Element}
* @protected
*/
this.container = null;
/**
* The actual RTCPeerConnection
* @type {RTCPeerConnection}
*/
this.pc = new RTCPeerConnection(
{
iceServers: cache.config.iceServers
},
{
optional: [DtlsSrtpKeyAgreement],
mandatory: sdpConstraints(!publish)
}
);
// Handle ICE candidates
this.pc.onicecandidate = e => {
if (!this.negotiated && e.candidate) {
Log.d('PeerConnection~onicecandidate', e.candidate);
DataSync.push(`${this._localPath}/ice`, _toJSON(e.candidate));
}
};
this.pc.oniceconnectionstatechange = () => {
Log.d('PeerConnection~oniceconnectionstatechange', this.pc);
const iceConnectionState = this.pc.iceConnectionState;
switch (iceConnectionState) {
case ICE_CONNECTION_STATE_CHECKING:
// Nothing to do yet
break;
case ICE_CONNECTION_STATE_CONNECTED:
this._attachStream();
this._remoteICECandidates(false);
break;
case ICE_CONNECTION_STATE_COMPLETED:
this._remoteICECandidates(false);
break;
case ICE_CONNECTION_STATE_DISCONNECTED:
case ICE_CONNECTION_STATE_FAILED:
Log.e('PeerConnection~stateDisconnected', 'Disconnect PeerConnection');
break;
case ICE_CONNECTION_STATE_CLOSED:
Log.d('PeerConnection~stateclosed', 'Close PeerConnection');
this.close();
break;
}
this.negotiated = this.negotiated || this.isConnected;
};
this.pc.onicegatheringstatechange = () => {
Log.d('PeerConnection~onicegatheringstatechange', this.pc.iceGatheringState);
};
/**
* PeerConnection status
* @type {string}
* @private
*/
this._status = OPENED;
}
/**
* Toggle ICE Candidates discovery
* @access private
* @param {boolean} listen Indicates if we should listen to new ICE candidates
*/
_remoteICECandidates(listen) {
const
path = `${this._remotePath}/ice`,
event = 'child_added';
if(listen) {
// don't listen to ice candidates if pc is already up (renegotiation)
DataSync.on(path, event, snap => {
const candidate = snap.val();
Log.d('PeerConnection~addIceCandidate', candidate);
this.pc.addIceCandidate(new RTCIceCandidate(candidate));
});
} else {
DataSync.off(path, event);
}
}
/**
* Attach the remote MediaStream to a node
* @access private
*/
_attachStream () {
if(this.remoteStream && this.isConnected) {
this.node = Media.attachStream(this.remoteStream, this.container, this.node);
this.node.muted = false;
}
}
/**
* The remote MediaStream
* @access protected
* @type {MediaStream}
*/
set remoteStream (stream) {
/**
* @ignore
*/
this._remoteStream = stream;
this._attachStream();
}
/**
* The remote MediaStream
* @type {MediaStream}
*/
get remoteStream () {
return this._remoteStream;
}
/**
* Indicates if the PeerConnection is established based on ICE connection state
* @returns {boolean}
*/
get isConnected () {
return this.pc &&
!!~[
ICE_CONNECTION_STATE_CONNECTED,
ICE_CONNECTION_STATE_COMPLETED,
ICE_CONNECTION_STATE_OTHER
].indexOf(this.pc.iceConnectionState);
}
/**
* Init RTCPeerConnection for subscribers
* @access protected
* @param htmlElement
* @returns {Promise.<PeerConnection>}
*/
answer(htmlElement) {
Log.i('PeerConnection~answer', {htmlElement, peerConnection: this});
this.container = htmlElement;
if(Object.getOwnPropertyDescriptor(RTCPeerConnection.prototype, 'ontrack')) {
this.pc.ontrack = e => {
Log.d('PeerConnection~ontrack', e.streams[0]);
this.remoteStream = e.streams[0];
};
} else {
this.pc.onaddstream = e => {
Log.d('PeerConnection~onaddstream', e.stream);
this.remoteStream = e.stream;
};
}
// Listen to SDP offer
DataSync.on(`${this._remotePath}/sdp`, 'value', snap => {
const sdpOffer = snap.val();
Log.d('Offer', sdpOffer);
if(sdpOffer != null) {
Log.d('PeerConnection~offered', sdpOffer);
this.pc.setRemoteDescription(sdpOffer)
.then(() => Log.d('PeerConnection~remoteDescription', this.pc.remoteDescription))
.then(() => {
if (/^offer$/.test(this.pc.remoteDescription.type)) {
return this.pc.createAnswer();
}
return Promise.reject(new Error('SDP is not an offer'));
})
.then(description => this._setPreferredCodecs(description))
.then(description => this.pc.setLocalDescription(description))
.then(() => {
Log.d('PeerConnection~localDescription', this.pc.localDescription);
this._remoteICECandidates(true);
})
.then(() => DataSync.update(`${this._localPath}/sdp`, _toJSON(this.pc.localDescription)))
.catch(Log.r('PeerConnection~localDescription'));
}
});
return Promise.resolve(this);
}
/**
* Init RTCPeerConnection for publishers
* @access protected
* @param stream
* @returns {Promise.<PeerConnection>}
*/
offer(stream) {
Log.i('PeerConnection~offer', {stream, peerConnection: this});
let sendTimeout;
return new Promise((resolve, reject) => {
this.pc.onnegotiationneeded = () => {
Log.d('PeerConnection~onnegotiationneeded');
// Debounce send (renegotiation triggers multiple negotiationneeded events)
if(sendTimeout) {
clearTimeout(sendTimeout);
sendTimeout = null;
}
sendTimeout = setTimeout(() => {
sendTimeout = null;
this._sendOffer()
.then(() => {
resolve(this);
})
.catch(e => {
Log.d('PeerConnection~offer', e);
reject(e);
});
}, 20);
};
DataSync.on(`${this._remotePath}/sdp`, 'value', snap => {
const sdpAnswer = snap.val();
if(sdpAnswer != null) {
Log.d('PeerConnection~offer#answered', sdpAnswer);
this.pc.setRemoteDescription(sdpAnswer)
.then(() => {
Log.d('PeerConnection~offer#remoteDescription', this.pc.remoteDescription);
this._remoteICECandidates(true);
})
.catch(Log.e.bind(Log, 'PeerConnection~remoteDescription'));
}
});
this._alterStream(stream, 'add');
});
}
/**
* Create SDP offer and push it
* @returns {Promise}
* @private
*/
_sendOffer() {
Log.d('PeerConnection~_sendOffer');
return this.pc.createOffer()
.then(description => this._setPreferredCodecs(description))
.then(description => this.pc.setLocalDescription(description))
.then(() => Log.d('PeerConnection~renegotiate#localDescription', this.pc.localDescription))
.then(() => DataSync.update(`${this._localPath}/sdp`, _toJSON(this.pc.localDescription)));
}
/**
* Add/Remove tracks to the PeerConnection stream
* @param {MediaStream} stream
* @param {string} method
* @private
*/
_alterStream(stream, method) {
if(Object.getOwnPropertyDescriptor(RTCPeerConnection.prototype, `${method}Track`)) {
stream.getTracks().forEach(track => this.pc[`${method}Track`](track, stream), this);
} else {
this.pc[`${method}Stream`](stream);
}
}
/**
* Restart SDP negotiation following a MediaStream change
* @access protected
* @param {MediaStream} oldStream
* @param {MediaStream} newStream
*/
renegotiate(oldStream, newStream) {
Log.d('PeerConnection~renegotiate');
if((Object.getOwnPropertyDescriptor(RTCPeerConnection.prototype, 'getSenders'))
&& ('RTCRtpSender' in window)
&& Object.getOwnPropertyDescriptor(RTCRtpSender.prototype, 'replaceTrack')){
// mozRTCPeerConnection implementation
this.pc.getSenders().forEach(sender => {
let newTracks;
switch (sender.track.kind) {
case 'audio':
newTracks = newStream.getAudioTracks();
break;
case 'video':
newTracks = newStream.getVideoTracks();
break;
default:
newTracks = [];
}
if(newTracks.length) {
sender.replaceTrack(newTracks[0]);
}
});
this._sendOffer()
.catch(e => {Log.d('PeerConnection~renegotiate', e);});
} else {
this._alterStream(oldStream, 'remove');
this._alterStream(newStream, 'add');
}
}
/**
* Close the PeerConnection and stop listening to SDP messages
* @access protected
*/
close() {
if(this._status === OPENED) {
this._status = CLOSING;
// Stop display
if (this.node) {
this.node.stop && this.node.stop();
this.node.srcObject = null;
this.container.removeChild(this.node);
this.node = null;
}
// Stop listening to remote ICE candidates
this._remoteICECandidates(false);
// Stop listening to SDP messages
DataSync.off(`${this._remotePath}/sdp`, 'value');
// Remove data
DataSync.remove(this._localPath);
// Close PeerConnection
if (this.pc && this.pc.signalingState !== 'closed') {
this.pc.onsignalingstatechange = () => {
if(this.pc.signalingState !== 'closed') {
this._status = CLOSED;
}
};
this.pc.close();
} else {
this._status = CLOSED;
}
}
}
/**
* Edits the SDP to set the preferred audio/video codec
* @access private
* @param {RTCSessionDescription} description The description retrieved by createOffer/createAnswer
* @returns {RTCSessionDescription|{sdp: string, type: string}}
*/
_setPreferredCodecs(description) {
if(cache.config.preferredVideoCodec || cache.config.preferredAudioCodec) {
Log.d('PeerConnection~_setPreferredCodecs', {description, config: cache.config});
const sdpLines = description.sdp.split(/\r?\n/);
const medias = {audio: [], video: []};
let current = null;
// Parse SDP
sdpLines.forEach((sdpLine, i) => {
if(/^m=/.test(sdpLine)) {
const d = /^m=(\w+)\s[0-9\/]+\s[A-Za-z0-9\/]+\s([0-9\s]+)/.exec(sdpLine);
current = {
fmt: d[2].split(/\s/),
index: i,
codecs: []
};
medias[d[1]].push(current);
} else if(current && /^a=rtpmap:/.test(sdpLine)) {
const c = /^a=rtpmap:(\d+)\s([a-zA-Z0-9\-\/]+)/.exec(sdpLine);
if(c) {
current.codecs.push({
id: c[1],
name: c[2],
index: i
});
}
}
});
Log.d('PeerConnection~_setPreferredCodecs', medias);
let update = false;
const prefer = (mediaList, preferedCodec) => {
mediaList.forEach(media => {
const selected = media.codecs.find(codec => preferedCodec.test(codec.name));
if(selected) {
const fmt = [selected.id].concat(media.fmt.filter(ids => ids !== selected.id));
sdpLines[media.index] = sdpLines[media.index].replace(media.fmt.join(' '), fmt.join(' '));
update = true;
}
});
};
if(cache.config.preferredVideoCodec) {
prefer(medias.video, cache.config.preferredVideoCodec);
}
if(cache.config.preferredAudioCodec) {
prefer(medias.audio, cache.config.preferredAudioCodec);
}
if(update) {
Log.d('PeerConnection~_setPreferredCodecs', sdpLines.join('\r\n'));
return {
sdp: sdpLines.join('\r\n'),
type: description.type
};
}
}
return description;
}
}
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