private HubMessage ParseMessage(TextReader textReader, IInvocationBinder binder)
{
try
{
// We parse using the JsonTextReader directly but this has a problem. Some of our properties are dependent on other properties
// and since reading the json might be unordered, we need to store the parsed content as JToken to re-parse when true types are known.
// if we're lucky and the state we need to directly parse is available, then we'll use it.
int? type = null;
string invocationId = null;
string target = null;
string error = null;
var hasItem = false;
object item = null;
JToken itemToken = null;
var hasResult = false;
object result = null;
JToken resultToken = null;
bool hasArguments = false;
object[] arguments = null;
JArray argumentsToken = null;
ExceptionDispatchInfo argumentBindingException = null;
Dictionary <string, string> headers = null;
var completed = false;
using (var reader = new JsonTextReader(textReader))
{
reader.ArrayPool = JsonArrayPool <char> .Shared;
JsonUtils.CheckRead(reader);
// We're always parsing a JSON object
if (reader.TokenType != JsonToken.StartObject)
{
throw new InvalidDataException($"Unexpected JSON Token Type '{JsonUtils.GetTokenString(reader.TokenType)}'. Expected a JSON Object.");
}
do
{
switch (reader.TokenType)
{
case JsonToken.PropertyName:
string memberName = reader.Value.ToString();
switch (memberName)
{
case TypePropertyName:
var messageType = JsonUtils.ReadAsInt32(reader, TypePropertyName);
if (messageType == null)
{
throw new InvalidDataException($"Missing required property '{TypePropertyName}'.");
}
type = messageType.Value;
break;
case InvocationIdPropertyName:
invocationId = JsonUtils.ReadAsString(reader, InvocationIdPropertyName);
break;
case TargetPropertyName:
target = JsonUtils.ReadAsString(reader, TargetPropertyName);
break;
case ErrorPropertyName:
error = JsonUtils.ReadAsString(reader, ErrorPropertyName);
break;
case ResultPropertyName:
JsonUtils.CheckRead(reader);
hasResult = true;
if (string.IsNullOrEmpty(invocationId))
{
// If we don't have an invocation id then we need to store it as a JToken so we can parse it later
resultToken = JToken.Load(reader);
}
else
{
// If we have an invocation id already we can parse the end result
var returnType = binder.GetReturnType(invocationId);
result = PayloadSerializer.Deserialize(reader, returnType);
}
break;
case ItemPropertyName:
JsonUtils.CheckRead(reader);
hasItem = true;
if (string.IsNullOrEmpty(invocationId))
{
// If we don't have an invocation id then we need to store it as a JToken so we can parse it later
itemToken = JToken.Load(reader);
}
else
{
var returnType = binder.GetReturnType(invocationId);
item = PayloadSerializer.Deserialize(reader, returnType);
}
break;
case ArgumentsPropertyName:
JsonUtils.CheckRead(reader);
if (reader.TokenType != JsonToken.StartArray)
{
throw new InvalidDataException($"Expected '{ArgumentsPropertyName}' to be of type {JTokenType.Array}.");
}
hasArguments = true;
if (string.IsNullOrEmpty(target))
{
// We don't know the method name yet so just parse an array of generic JArray
argumentsToken = JArray.Load(reader);
}
else
{
try
{
var paramTypes = binder.GetParameterTypes(target);
arguments = BindArguments(reader, paramTypes);
}
catch (Exception ex)
{
argumentBindingException = ExceptionDispatchInfo.Capture(ex);
}
}
break;
case HeadersPropertyName:
JsonUtils.CheckRead(reader);
headers = ReadHeaders(reader);
break;
default:
// Skip read the property name
JsonUtils.CheckRead(reader);
// Skip the value for this property
reader.Skip();
break;
}
break;
case JsonToken.EndObject:
completed = true;
break;
}
}while (!completed && JsonUtils.CheckRead(reader));
}
HubMessage message;
switch (type)
{
case HubProtocolConstants.InvocationMessageType:
{
if (argumentsToken != null)
{
try
{
var paramTypes = binder.GetParameterTypes(target);
arguments = BindArguments(argumentsToken, paramTypes);
}
catch (Exception ex)
{
argumentBindingException = ExceptionDispatchInfo.Capture(ex);
}
}
message = BindInvocationMessage(invocationId, target, argumentBindingException, arguments, hasArguments, binder);
}
break;
case HubProtocolConstants.StreamInvocationMessageType:
{
if (argumentsToken != null)
{
try
{
var paramTypes = binder.GetParameterTypes(target);
arguments = BindArguments(argumentsToken, paramTypes);
}
catch (Exception ex)
{
argumentBindingException = ExceptionDispatchInfo.Capture(ex);
}
}
message = BindStreamInvocationMessage(invocationId, target, argumentBindingException, arguments, hasArguments, binder);
}
break;
case HubProtocolConstants.StreamItemMessageType:
if (itemToken != null)
{
var returnType = binder.GetReturnType(invocationId);
item = itemToken.ToObject(returnType, PayloadSerializer);
}
message = BindStreamItemMessage(invocationId, item, hasItem, binder);
break;
case HubProtocolConstants.CompletionMessageType:
if (resultToken != null)
{
var returnType = binder.GetReturnType(invocationId);
result = resultToken.ToObject(returnType, PayloadSerializer);
}
message = BindCompletionMessage(invocationId, error, result, hasResult, binder);
break;
case HubProtocolConstants.CancelInvocationMessageType:
message = BindCancelInvocationMessage(invocationId);
break;
case HubProtocolConstants.PingMessageType:
return(PingMessage.Instance);
case HubProtocolConstants.CloseMessageType:
return(BindCloseMessage(error));
case null:
throw new InvalidDataException($"Missing required property '{TypePropertyName}'.");
default:
throw new InvalidDataException($"Unknown message type: {type}");
}
return(ApplyHeaders(message, headers));
}
catch (JsonReaderException jrex)
{
throw new InvalidDataException("Error reading JSON.", jrex);
}
}
private void WriteMessageCore(HubMessage message, IBufferWriter <byte> stream)
{
var textWriter = Utf8BufferTextWriter.Get(stream);
try
{
using (var writer = JsonUtils.CreateJsonTextWriter(textWriter))
{
writer.WriteStartObject();
switch (message)
{
case InvocationMessage m:
WriteMessageType(writer, HubProtocolConstants.InvocationMessageType);
WriteHeaders(writer, m);
WriteInvocationMessage(m, writer);
break;
case StreamInvocationMessage m:
WriteMessageType(writer, HubProtocolConstants.StreamInvocationMessageType);
WriteHeaders(writer, m);
WriteStreamInvocationMessage(m, writer);
break;
case StreamItemMessage m:
WriteMessageType(writer, HubProtocolConstants.StreamItemMessageType);
WriteHeaders(writer, m);
WriteStreamItemMessage(m, writer);
break;
case CompletionMessage m:
WriteMessageType(writer, HubProtocolConstants.CompletionMessageType);
WriteHeaders(writer, m);
WriteCompletionMessage(m, writer);
break;
case CancelInvocationMessage m:
WriteMessageType(writer, HubProtocolConstants.CancelInvocationMessageType);
WriteHeaders(writer, m);
WriteCancelInvocationMessage(m, writer);
break;
case PingMessage _:
WriteMessageType(writer, HubProtocolConstants.PingMessageType);
break;
case CloseMessage m:
WriteMessageType(writer, HubProtocolConstants.CloseMessageType);
WriteCloseMessage(m, writer);
break;
default:
throw new InvalidOperationException($"Unsupported message type: {message.GetType().FullName}");
}
writer.WriteEndObject();
writer.Flush();
}
}
finally
{
Utf8BufferTextWriter.Return(textWriter);
}
}
public static bool TryParseResponseMessage(ref ReadOnlySequence <byte> buffer, out HandshakeResponseMessage responseMessage)
{
if (!TextMessageParser.TryParseMessage(ref buffer, out var payload))
{
responseMessage = null;
return(false);
}
var textReader = Utf8BufferTextReader.Get(payload);
try
{
using (var reader = JsonUtils.CreateJsonTextReader(textReader))
{
JsonUtils.CheckRead(reader);
JsonUtils.EnsureObjectStart(reader);
string error = null;
var completed = false;
while (!completed && JsonUtils.CheckRead(reader))
{
switch (reader.TokenType)
{
case JsonToken.PropertyName:
string memberName = reader.Value.ToString();
switch (memberName)
{
case TypePropertyName:
// a handshake response does not have a type
// check the incoming message was not any other type of message
throw new InvalidDataException("Handshake response should not have a 'type' value.");
case ErrorPropertyName:
error = JsonUtils.ReadAsString(reader, ErrorPropertyName);
break;
default:
reader.Skip();
break;
}
break;
case JsonToken.EndObject:
completed = true;
break;
default:
throw new InvalidDataException($"Unexpected token '{reader.TokenType}' when reading handshake response JSON.");
}
}
;
responseMessage = (error != null) ? new HandshakeResponseMessage(error) : HandshakeResponseMessage.Empty;
return(true);
}
}
finally
{
Utf8BufferTextReader.Return(textReader);
}
}
private CancelInvocationMessage BindCancelInvocationMessage(JObject json)
{
var invocationId = JsonUtils.GetRequiredProperty <string>(json, InvocationIdPropertyName, JTokenType.String);
return(new CancelInvocationMessage(invocationId));
}
public static bool TryParseRequestMessage(ref ReadOnlySequence <byte> buffer, out HandshakeRequestMessage requestMessage)
{
if (!TextMessageParser.TryParseMessage(ref buffer, out var payload))
{
requestMessage = null;
return(false);
}
var textReader = Utf8BufferTextReader.Get(payload);
try
{
using (var reader = JsonUtils.CreateJsonTextReader(textReader))
{
JsonUtils.CheckRead(reader);
JsonUtils.EnsureObjectStart(reader);
string protocol = null;
int? protocolVersion = null;
var completed = false;
while (!completed && JsonUtils.CheckRead(reader))
{
switch (reader.TokenType)
{
case JsonToken.PropertyName:
string memberName = reader.Value.ToString();
switch (memberName)
{
case ProtocolPropertyName:
protocol = JsonUtils.ReadAsString(reader, ProtocolPropertyName);
break;
case ProtocolVersionPropertyName:
protocolVersion = JsonUtils.ReadAsInt32(reader, ProtocolVersionPropertyName);
break;
default:
reader.Skip();
break;
}
break;
case JsonToken.EndObject:
completed = true;
break;
default:
throw new InvalidDataException($"Unexpected token '{reader.TokenType}' when reading handshake request JSON.");
}
}
if (protocol == null)
{
throw new InvalidDataException($"Missing required property '{ProtocolPropertyName}'.");
}
if (protocolVersion == null)
{
throw new InvalidDataException($"Missing required property '{ProtocolVersionPropertyName}'.");
}
requestMessage = new HandshakeRequestMessage(protocol, protocolVersion.Value);
}
}
finally
{
Utf8BufferTextReader.Return(textReader);
}
return(true);
}
