yjs/lib/Connectors/PeerJsConnector.coffee

152 lines
4.9 KiB
CoffeeScript

#
# @overload createPeerJsConnector peerjs_options, callback
# @param {Object} peerjs_options Is the options object that is passed to PeerJs.
# @param {Function} callback The callback is called when the connector is initialized.
# @overload createPeerJsConnector peerjs_user_id, peerjs_options, callback
# @param {String} peerjs_user_id The user_id that is passed to PeerJs as the user_id and should be unique between all (also the unconnected) Peers.
# @param {Object} peerjs_options Is the options object that is passed to PeerJs.
# @param {Function} callback The callback is called when the connector is initialized.
#
createPeerJsConnector = ()->
peer = null
if arguments.length is 2
peer = new Peer arguments[0]
callback = arguments[1]
else
peer = new Peer arguments[0], arguments[1]
peer.on 'error', (err)->
throw new Error "Peerjs connector: #{err}"
peer.on 'disconnected', ()->
throw new Error "Peerjs connector disconnected from signalling server. Cannot accept new connections. Not fatal, but not so good either.."
callback = arguments[2]
#
# PeerJs is a Framework that enables you to connect to other peers. You just need the
# user-id of the peer (browser/client). And then you can connect to it.
# @see http://peerjs.com
#
class PeerJsConnector
#
# @param {Engine} engine The transformation engine
# @param {HistoryBuffer} HB
# @param {Array<Function>} execution_listener You must ensure that whenever an operation is executed, every function in this Array is called.
# @param {Yatta} yatta The Yatta framework.
#
constructor: (@engine, @HB, @execution_listener, @yatta)->
@peer = peer
@connections = {}
@new_connection_listeners = []
@peer.on 'connection', (conn)=>
@addConnection conn
sync_every_collaborator = ()=>
for conn_id, conn of @connections
conn.send
sync_state_vector: @HB.getOperationCounter()
setInterval sync_every_collaborator, 4000
send_ = (o)=>
if o.uid.creator is @HB.getUserId() and (typeof o.uid.op_number isnt "string")
for conn_id,conn of @connections
conn.send
op: o
@execution_listener.push send_
#
# Connect the Framework to another peer. Therefore you have to receive his
# user_id. If the other peer is connected to other peers, the PeerJsConnector
# will automatically connect to them too.
#
# Transmitting the user_id is your job.
# See [TextEditing](../../examples/TextEditing/) for a nice example
# on how to do that with urls.
#
# @param id {String} Connection id
#
connectToPeer: (id)->
if not @connections[id]? and id isnt @yatta.getUserId()
@addConnection peer.connect id
#
# Receive the id of every connected peer.
# @return {Array<String>} A list of Peer-Ids
#
getAllConnectionIds: ()->
for conn_id of @connections
conn_id
onNewConnection: (f)->
@new_connection_listeners.push f
#
# Adds an existing connection to this connector.
# @param conn {PeerJsConnection}
#
addConnection: (conn)->
#
# What this method does:
# * Send state vector
# * Receive HB -> apply them
# * Send connections
# * Receive Connections -> Connect to unknow connections
@connections[conn.peer] = conn
initialized_me = false
initialized_him = false
conn.on 'data', (data)=>
if data is "empty_message"
# nop
else if data.HB?
initialized_me = true
@engine.applyOpsCheckDouble data.HB
if not data.initialized
conn.send
conns: @getAllConnectionIds()
@new_connection_listeners.map (f)->
f(conn)
else if data.op?
@engine.applyOp data.op
else if data.conns?
for conn_id in data.conns
@connectToPeer conn_id
else if data.sync_state_vector?
conn.send
HB: @yatta.getHistoryBuffer()._encode(data.sync_state_vector)
initialized: true
else if data.state_vector?
if not initialized_him
# make sure, that it is sent only once
conn.send
HB: @yatta.getHistoryBuffer()._encode(data.state_vector)
initialized: false
initialized_him = true
else
throw new Error "Can't parse this operation: #{data}"
sendStateVector = ()=>
conn.send
state_vector: @HB.getOperationCounter()
if not initialized_me
# Because of a bug in PeerJs,
# we never know if state vector was actually sent
setTimeout sendStateVector, 100
sendStateVector()
peer.on 'open', (id)->
callback PeerJsConnector, id
module.exports = createPeerJsConnector
if window?
if not window.Y?
window.Y = {}
window.Y.createPeerJsConnector = createPeerJsConnector