dxFeed C API and dxFeed .NET API version 7.1.0 with fixes and improvements are already available.

C API Changelog

• Implemented the heartbeat semantics with payload
  • Added the new function dxf_set_on_server_heartbeat_notifier(dxf_connection_t connection, dxf_conn_on_server_heartbeat_notifier_t notifier, void* user_data)
    that sets a server heartbeat notifier’s callback to the connection.
    This notifier will be invoked when the new heartbeat arrives from a server and contains non empty payload
    Function parameters:
    • connection – The handle of a previously created connection
    • notifier – The notifier callback function pointer
    • user_data – The data to be passed to the callback function
  • Added the new callback type of a connection incoming heartbeat notification dxf_conn_on_server_heartbeat_notifier_t
    Passed parameters:
    • connection – The connection handle
    • server_millis – The server time in milliseconds (from the incoming heartbeat payload)
    • server_lag_mark – The server’s messages composing lag time in microseconds (from the incoming heartbeat payload)
    • connection_rtt – The calculated connection RTT in microseconds
    • user_data – The user data passed to dxf_set_on_server_heartbeat_notifier
      An example of implementation:

  void on_server_heartbeat_notifier(dxf_connection_t connection, dxf_long_t server_millis, dxf_int_t server_lag_mark,        
      dxf_int_t connection_rtt, void* user_data)
  {
      fwprintf(stderr, L"\n##### Server time (UTC) = %" PRId64 " ms, Server lag = %d us, RTT = %d us #####\n",
          server_millis, server_lag_mark, connection_rtt);
  }

  See usage example in the CommandLineSample.c

 

.NET API Changelog

• Implemented the heartbeat semantics with payload

  • Added the new method NativeConnection.SetOnServerHeartbeatHandler(OnServerHeartbeatHandler handler)
    that sets a handler that will be called when a server heartbeat arrives and contains non empty payload

  • Added the new delegate type delegate void OnServerHeartbeatHandler(IDxConnection connection, DateTime serverDateTime, int serverLagMark, int connectionRtt)
    which is describes the handler type of a connection’s incoming heartbeat notification
    Passed parameters:

    • connection – The current connection object
    • serverDateTime – The server UTC time (from the incoming heartbeat payload)
    • serverLagMark – The server’s messages composing lag time in microseconds (from the incoming heartbeat payload)
    • connectionRtt – The calculated connection RTT in microseconds

    An example of usage:

    connection.SetOnServerHeartbeatHandler((connection, time, lagMark, rtt) => {
        Console.Error.WriteLine($"##### Server time (UTC) = {time}, Server lag = {lagMark} us, RTT = {rtt} us #####");
    });