void _changeState()

in lib/src/streams/stream_handler.dart [815:865]
42 lines of code
39 McCabe index (conditional complexity)

  void _changeState(Http2StreamImpl stream, StreamState to) {
    var from = stream.state;

    // In checked mode we'll test that the state transition is allowed.
    assert((from == StreamState.Idle && to == StreamState.ReservedLocal) ||
        (from == StreamState.Idle && to == StreamState.ReservedRemote) ||
        (from == StreamState.Idle && to == StreamState.Open) ||
        (from == StreamState.Open && to == StreamState.HalfClosedLocal) ||
        (from == StreamState.Open && to == StreamState.HalfClosedRemote) ||
        (from == StreamState.Open && to == StreamState.Closed) ||
        (from == StreamState.HalfClosedLocal && to == StreamState.Closed) ||
        (from == StreamState.HalfClosedRemote && to == StreamState.Closed) ||
        (from == StreamState.ReservedLocal &&
            to == StreamState.HalfClosedRemote) ||
        (from == StreamState.ReservedLocal && to == StreamState.Closed) ||
        (from == StreamState.ReservedRemote && to == StreamState.Closed) ||
        (from == StreamState.ReservedRemote &&
            to == StreamState.HalfClosedLocal) ||
        (from != StreamState.Terminated && to == StreamState.Terminated));

    // If we initiated the stream and it became "open" or "closed" we need to
    // update the [_numberOfActiveStreams] counter.
    if (_didInitiateStream(stream)) {
      // NOTE: We wait until the stream is completely done.
      // (If we waited only until `StreamState.Closed` then we might still have
      //  the endStream header/data message buffered, but not yet sent out).
      switch (stream.state) {
        case StreamState.ReservedLocal:
        case StreamState.ReservedRemote:
        case StreamState.Idle:
          if (to == StreamState.Open ||
              to == StreamState.HalfClosedLocal ||
              to == StreamState.HalfClosedRemote) {
            _numberOfActiveStreams++;
          }
          break;
        case StreamState.Open:
        case StreamState.HalfClosedLocal:
        case StreamState.HalfClosedRemote:
        case StreamState.Closed:
          if (to == StreamState.Terminated) {
            _numberOfActiveStreams--;
          }
          break;
        case StreamState.Terminated:
          // There is nothing to do here.
          break;
      }
    }
    stream.state = to;
  }