internal virtual async ValueTask ReceiveInitializeFrameAsync(CancellationToken cancel)
{
byte frameType = _socket.Endpoint.Protocol == Protocol.Ice1 ?
(byte)Ice1FrameType.ValidateConnection : (byte)Ice2FrameType.Initialize;
ArraySegment <byte> data = await ReceiveFrameAsync(frameType, cancel).ConfigureAwait(false);
if (ReceivedEndOfStream)
{
throw new InvalidDataException($"received unexpected end of stream after initialize frame");
}
if (_socket.Endpoint.Communicator.TraceLevels.Protocol >= 1)
{
TraceFrame(data, frameType);
}
if (_socket.Endpoint.Protocol == Protocol.Ice1)
{
if (data.Count > 0)
{
throw new InvalidDataException(
@$ "received an ice1 frame with validate connection type and a size of `{data.Count}' bytes");
}
}
else
{
// Read the protocol parameters which are encoded with the binary context encoding.
var istr = new InputStream(data, Ice2Definitions.Encoding);
int dictionarySize = istr.ReadSize();
for (int i = 0; i < dictionarySize; ++i)
{
(int key, ReadOnlyMemory <byte> value) = istr.ReadBinaryContextEntry();
if (key == (int)Ice2ParameterKey.IncomingFrameMaxSize)
{
checked
{
_socket.PeerIncomingFrameMaxSize = (int)value.Span.ReadVarULong().Value;
}
if (_socket.PeerIncomingFrameMaxSize < 1024)
{
throw new InvalidDataException($@"the peer's IncomingFrameMaxSize ({
_socket.PeerIncomingFrameMaxSize} bytes) value is inferior to 1KB");
}
}
else
{
// Ignore unsupported parameters.
}
}
if (_socket.PeerIncomingFrameMaxSize == null)
{
throw new InvalidDataException("missing IncomingFrameMaxSize Ice2 connection parameter");
}
}
}
/// <summary>Reads a binary context from the stream.</summary>
/// <param name="istr">The input stream.</param>
/// <returns>The binary context as an immutable dictionary.</returns>
/// <remarks>The values of the dictionary reference memory in the stream's underlying buffer.</remarks>
public static ImmutableDictionary <int, ReadOnlyMemory <byte> > ReadBinaryContext(this InputStream istr)
{
Debug.Assert(istr.Encoding == Encoding.V20);
int size = istr.ReadSize();
if (size == 0)
{
return(ImmutableDictionary <int, ReadOnlyMemory <byte> > .Empty);
}
else
{
var builder = ImmutableDictionary.CreateBuilder <int, ReadOnlyMemory <byte> >();
for (int i = 0; i < size; ++i)
{
(int key, ReadOnlyMemory <byte> value) = istr.ReadBinaryContextEntry();
builder.Add(key, value);
}
return(builder.ToImmutable());
}
}
