I'm not native to networking so maybe I'm misunderstanding how endPoint information is gathered.
Device_A is browsing and discovers Device_B or the other way around, it doesn't matter because they will both discover each other and send data to open a connection. Because the Network framework does not resolve ipAddresses, - https://developer.apple.com/forums/thread/129644 when a connection is first made I use either the remoteEndPoint (connection.currentPath?.remoteEndpoint // fe80::9821:7fff:fcea:74c4%awdl0.10059) or the endPoint description (connection.endpoint.debugDescription // myApp (2)._myApp._tcplocal.) as a uniqueID for the connection.
I send the data and some other info across the wire, if successful I then place either endPoint inside an ivar dictionary as the key with another value so that I know which device to map a response to once a device responds back.
Right now I only have 2 devices connected, the issue is when I receive a response from Device_B, I'm actually getting the incorrect endPoint information. For some reason I keep getting the endPoint info from Device_A back. It seems like the same endPoint information is getting sent twice. Once to Device_A and then again to Device_B. This exact same thing occurs on Device_B but in reverse. I'm confused as to why this is happening.
For example Device_A first discovers itself, the remoteEndPoint is *fe80::9821:7fff:fcea:74c4%awdl0.10059*, it sends the data. When Device_A receives its own message, I filter it out using the userId and I see the same endPoint info. But when Device_A discovers Device_B, the remoteEndPoint is *fe80::9821:7fff:fcea:74c4%awdl0.27788*. When I receive a response from Device_B, the endPoint information is showing the first one from Device_A *fe80::9821:7fff:fcea:74c4%awdl0.10059*. The same remoteEndPoint info is duplicated. The same exact thing is happening if I use endpoint.debugDescription. This issue occurs on both devices.
NWBrowser:
browser.browseResultsChangedHandler = { (results, changes) in
for change in changes {
switch change {
case .added(let browseResult):
switch browseResult.endpoint {
case .service(let name, let type,_,_):
let connection = PeerConnection(to: browseResult.endpoint)
// ...
}
PeerConnection:
var connection: NWConnection?
init(to endPoint: NWEndpoint) {
// tcpOptions ...
// params ...
// initialize connection and delegate that sends out data
connection.stateUpdateHandler = { (nwConnectionState) in
case .ready:
self.delegate.sendOutgoing(connection)
}
Send Data:
var dict = [String:String]()
var endPointArr = [String]()
func sendOutgoing(_ connection: NWConnection) {
let endPoint = connection.currentPath?.localEndpoint?.debugDescription
or
let endPoint = connection.currentPath?.remoteEndpoint?.debugDescription
// encode the endPoint and currentUserId with some other info, then send it across the wire, if successful make the endPoint a key inside a dictionary and add it to an array to keep track of what endPoints were received
connection.send(content: encodedData, contentContext: context, isComplete: true, completion: .contentProcessed({ [weak self](error) in {
if let error = error { return }
self?.dict[endPoint] = someUniqueValue
self?.endPointArr.append(endPoint)
}))
}
Receiving a response
connection.receive(minimumIncompleteLength: 1, maximumLength: 65535) { [weak self](data, context, isComplete, error) {
if let err = error { return }
if let data = data, !data.isEmpty {
self?.received(data)
}
}
func received(_ data) {
guard let retrievedData = try! NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(data) as? MyModel else { return }
guard let endPoint = retrievedData.endPoint as? String, let userID = retrievedData.userId as? String else { return }
print(endPoint) // fe80::9821:7fff:fcea:74c4%awdl0.10059
if userID == Auth.auth().currentUser?.uid {
dict[endPoint] = nil
return
}
endPointArr.forEach { (endPoint) in
print(endPoint) // prints both fe80::9821:7fff:fcea:74c4%awdl0.10059 and fe80::9821:7fff:fcea:74c4%awdl0.27788
}
// this never runs because the key just got set to nil above because Device_B has the same endPoint info
for (key, value) in dict where key == endpoint {
print("key=\(key) : value=\(value)") // someUniqueValue
// show response that this is a response from whichever device has this endPoint
break
}
}
[1]: https://developer.apple.com/forums/thread/129644