/// <summary>Reads client messages.</summary>
/// <param name="webSocket"> The web socket.</param>
/// <param name="clientGuid"> Unique identifier for the client.</param>
/// <param name="cancelToken">A token that allows processing to be cancelled.</param>
/// <returns>An asynchronous result.</returns>
private async Task ReadClientMessages(
WebSocket webSocket,
Guid clientGuid,
CancellationToken cancelToken)
{
// get the client object
if (!WebsocketManager.TryGetClient(clientGuid, out WebsocketClientInformation client))
{
// nothing to do here (will cancel on exit)
return;
}
// create our receive buffer
byte[] buffer = new byte[_messageBufferSize];
int count;
int messageLength = 0;
WebSocketReceiveResult result;
// loop until cancelled
while (!cancelToken.IsCancellationRequested)
{
// reset buffer offset
messageLength = 0;
// do not bubble errors here
try
{
// read a message
do
{
count = _messageBufferSize - messageLength;
result = await webSocket.ReceiveAsync(
new ArraySegment <byte>(
buffer,
messageLength,
count),
cancelToken).ConfigureAwait(false);
messageLength += result.Count;
}while (!result.EndOfMessage);
// process this message
if (result.MessageType == WebSocketMessageType.Close)
{
break;
}
// check for a bind request
string message = Encoding.UTF8.GetString(buffer).Substring(0, messageLength);
if (message.StartsWith("bind ", StringComparison.Ordinal))
{
// grab the rest of the content
message = message.Replace("bind ", string.Empty, StringComparison.Ordinal);
string[] ids = message.Split(',');
// traverse the requested ids
foreach (string id in ids)
{
string subscriptionId = id.StartsWith("Subscription/", StringComparison.Ordinal)
? id.Replace("Subscription/", string.Empty, StringComparison.Ordinal)
: id;
// make sure this subscription exists
if ((!SubscriptionManagerR4.Exists(subscriptionId)) &&
(!SubscriptionManagerR5.Exists(subscriptionId)))
{
continue;
}
// register this subscription to this client
WebsocketManager.AddSubscriptionToClient(subscriptionId, clientGuid);
}
}
if (message.StartsWith("bind-with-token ", StringComparison.Ordinal))
{
// grab the rest of the content
message = message.Replace("bind-with-token ", string.Empty, StringComparison.Ordinal);
if (!Guid.TryParse(message, out Guid tokenGuid))
{
continue;
}
// register this token to this client
WebsocketManager.BindClientWithToken(tokenGuid, clientGuid);
}
if (message.StartsWith("unbind ", StringComparison.Ordinal))
{
// grab the rest of the content
message = message.Replace("unbind ", string.Empty, StringComparison.Ordinal);
string[] ids = message.Split(',');
// traverse the requested ids
foreach (string id in ids)
{
string subscriptionId = id.StartsWith("Subscription/", StringComparison.Ordinal)
? id.Replace("Subscription/", string.Empty, StringComparison.Ordinal)
: id;
// remove this subscription from this client
WebsocketManager.RemoveSubscriptionFromClient(subscriptionId, clientGuid);
}
}
}
// keep looping
catch (Exception ex)
{
Console.WriteLine($"SubscriptionWebsocketHandler.ReadClientMessages" +
$" <<< client: {clientGuid} caught exception: {ex.Message}");
// this socket is borked, exit
break;
}
}
}
