private HubMessage?ParseMessage(ReadOnlySequence <byte> input, IInvocationBinder binder)
{
try
{
// We parse using the Utf8JsonReader 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 JsonDocument 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;
var hasResult = false;
object? result = null;
var hasArguments = false;
object?[]? arguments = null;
string[]? streamIds = null;
bool hasArgumentsToken = false;
Utf8JsonReader argumentsToken = default;
bool hasItemsToken = false;
Utf8JsonReader itemsToken = default;
bool hasResultToken = false;
Utf8JsonReader resultToken = default;
ExceptionDispatchInfo? argumentBindingException = null;
Dictionary <string, string>?headers = null;
var completed = false;
var allowReconnect = false;
var reader = new Utf8JsonReader(input, isFinalBlock: true, state: default);
reader.CheckRead();
// We're always parsing a JSON object
reader.EnsureObjectStart();
do
{
switch (reader.TokenType)
{
case JsonTokenType.PropertyName:
if (reader.ValueTextEquals(TypePropertyNameBytes.EncodedUtf8Bytes))
{
type = reader.ReadAsInt32(TypePropertyName);
if (type == null)
{
throw new InvalidDataException($"Expected '{TypePropertyName}' to be of type {JsonTokenType.Number}.");
}
}
else if (reader.ValueTextEquals(InvocationIdPropertyNameBytes.EncodedUtf8Bytes))
{
invocationId = reader.ReadAsString(InvocationIdPropertyName);
}
else if (reader.ValueTextEquals(StreamIdsPropertyNameBytes.EncodedUtf8Bytes))
{
reader.CheckRead();
if (reader.TokenType != JsonTokenType.StartArray)
{
throw new InvalidDataException(
$"Expected '{StreamIdsPropertyName}' to be of type {SystemTextJsonExtensions.GetTokenString(JsonTokenType.StartArray)}.");
}
var newStreamIds = new List <string>();
reader.Read();
while (reader.TokenType != JsonTokenType.EndArray)
{
newStreamIds.Add(reader.GetString() ?? throw new InvalidDataException($"Null value for '{StreamIdsPropertyName}' is not valid."));
reader.Read();
}
streamIds = newStreamIds.ToArray();
}
else if (reader.ValueTextEquals(TargetPropertyNameBytes.EncodedUtf8Bytes))
{
target = reader.ReadAsString(TargetPropertyName);
}
else if (reader.ValueTextEquals(ErrorPropertyNameBytes.EncodedUtf8Bytes))
{
error = reader.ReadAsString(ErrorPropertyName);
}
else if (reader.ValueTextEquals(AllowReconnectPropertyNameBytes.EncodedUtf8Bytes))
{
allowReconnect = reader.ReadAsBoolean(AllowReconnectPropertyName);
}
else if (reader.ValueTextEquals(ResultPropertyNameBytes.EncodedUtf8Bytes))
{
hasResult = true;
reader.CheckRead();
if (string.IsNullOrEmpty(invocationId))
{
// If we don't have an invocation id then we need to value copy the reader so we can parse it later
hasResultToken = true;
resultToken = reader;
reader.Skip();
}
else
{
// If we have an invocation id already we can parse the end result
var returnType = binder.GetReturnType(invocationId);
result = BindType(ref reader, returnType);
}
}
else if (reader.ValueTextEquals(ItemPropertyNameBytes.EncodedUtf8Bytes))
{
reader.CheckRead();
hasItem = true;
string?id = null;
if (!string.IsNullOrEmpty(invocationId))
{
id = invocationId;
}
else
{
// If we don't have an id yet then we need to value copy the reader so we can parse it later
hasItemsToken = true;
itemsToken = reader;
reader.Skip();
continue;
}
try
{
var itemType = binder.GetStreamItemType(id);
item = BindType(ref reader, itemType);
}
catch (Exception ex)
{
return(new StreamBindingFailureMessage(id, ExceptionDispatchInfo.Capture(ex)));
}
}
else if (reader.ValueTextEquals(ArgumentsPropertyNameBytes.EncodedUtf8Bytes))
{
reader.CheckRead();
int initialDepth = reader.CurrentDepth;
if (reader.TokenType != JsonTokenType.StartArray)
{
throw new InvalidDataException($"Expected '{ArgumentsPropertyName}' to be of type {SystemTextJsonExtensions.GetTokenString(JsonTokenType.StartArray)}.");
}
hasArguments = true;
if (string.IsNullOrEmpty(target))
{
// We don't know the method name yet so just value copy the reader so we can parse it later
hasArgumentsToken = true;
argumentsToken = reader;
reader.Skip();
}
else
{
try
{
var paramTypes = binder.GetParameterTypes(target);
arguments = BindTypes(ref reader, paramTypes);
}
catch (Exception ex)
{
argumentBindingException = ExceptionDispatchInfo.Capture(ex);
// Could be at any point in argument array JSON when an error is thrown
// Read until the end of the argument JSON array
while (reader.CurrentDepth == initialDepth && reader.TokenType == JsonTokenType.StartArray ||
reader.CurrentDepth > initialDepth)
{
reader.CheckRead();
}
}
}
}
else if (reader.ValueTextEquals(HeadersPropertyNameBytes.EncodedUtf8Bytes))
{
reader.CheckRead();
headers = ReadHeaders(ref reader);
}
else
{
reader.CheckRead();
reader.Skip();
}
break;
case JsonTokenType.EndObject:
completed = true;
break;
}
}while (!completed && reader.CheckRead());
HubMessage message;
switch (type)
{
case HubProtocolConstants.InvocationMessageType:
{
if (target is null)
{
throw new InvalidDataException($"Missing required property '{TargetPropertyName}'.");
}
if (hasArgumentsToken)
{
// We weren't able to bind the arguments because they came before the 'target', so try to bind now that we've read everything.
try
{
var paramTypes = binder.GetParameterTypes(target);
arguments = BindTypes(ref argumentsToken, paramTypes);
}
catch (Exception ex)
{
argumentBindingException = ExceptionDispatchInfo.Capture(ex);
}
}
message = argumentBindingException != null
? new InvocationBindingFailureMessage(invocationId, target, argumentBindingException)
: BindInvocationMessage(invocationId, target, arguments, hasArguments, streamIds);
}
break;
case HubProtocolConstants.StreamInvocationMessageType:
{
if (target is null)
{
throw new InvalidDataException($"Missing required property '{TargetPropertyName}'.");
}
if (hasArgumentsToken)
{
// We weren't able to bind the arguments because they came before the 'target', so try to bind now that we've read everything.
try
{
var paramTypes = binder.GetParameterTypes(target);
arguments = BindTypes(ref argumentsToken, paramTypes);
}
catch (Exception ex)
{
argumentBindingException = ExceptionDispatchInfo.Capture(ex);
}
}
message = argumentBindingException != null
? new InvocationBindingFailureMessage(invocationId, target, argumentBindingException)
: BindStreamInvocationMessage(invocationId, target, arguments, hasArguments, streamIds);
}
break;
case HubProtocolConstants.StreamItemMessageType:
if (invocationId is null)
{
throw new InvalidDataException($"Missing required property '{InvocationIdPropertyName}'.");
}
if (hasItemsToken)
{
try
{
var returnType = binder.GetStreamItemType(invocationId);
item = BindType(ref itemsToken, returnType);
}
catch (JsonException ex)
{
message = new StreamBindingFailureMessage(invocationId, ExceptionDispatchInfo.Capture(ex));
break;
}
}
message = BindStreamItemMessage(invocationId, item, hasItem, binder);
break;
case HubProtocolConstants.CompletionMessageType:
if (invocationId is null)
{
throw new InvalidDataException($"Missing required property '{InvocationIdPropertyName}'.");
}
if (hasResultToken)
{
var returnType = binder.GetReturnType(invocationId);
result = BindType(ref resultToken, returnType);
}
message = BindCompletionMessage(invocationId, error, result, hasResult, binder);
break;
case HubProtocolConstants.CancelInvocationMessageType:
message = BindCancelInvocationMessage(invocationId);
break;
case HubProtocolConstants.PingMessageType:
return(PingMessage.Instance);
case HubProtocolConstants.CloseMessageType:
return(BindCloseMessage(error, allowReconnect));
case null:
throw new InvalidDataException($"Missing required property '{TypePropertyName}'.");
default:
// Future protocol changes can add message types, old clients can ignore them
return(null);
}
return(ApplyHeaders(message, headers));
}
catch (JsonException jrex)
{
throw new InvalidDataException("Error reading JSON.", jrex);
}
}
private HubMessage ParseMessage(Utf8BufferTextReader 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;
var hasArguments = false;
object[] arguments = null;
string[] streamIds = null;
JArray argumentsToken = null;
ExceptionDispatchInfo argumentBindingException = null;
Dictionary <string, string> headers = null;
var completed = false;
var allowReconnect = false;
using (var reader = JsonUtils.CreateJsonTextReader(textReader))
{
reader.DateParseHandling = DateParseHandling.None;
JsonUtils.CheckRead(reader);
// We're always parsing a JSON object
JsonUtils.EnsureObjectStart(reader);
do
{
switch (reader.TokenType)
{
case JsonToken.PropertyName:
var memberName = reader.Value.ToString();
switch (memberName)
{
case TypePropertyName:
var messageType = JsonUtils.ReadAsInt32(reader, TypePropertyName);
if (messageType == null)
{
throw new InvalidDataException($"Missing required property '{TypePropertyName}'.");
}
type = messageType.Value;
break;
case InvocationIdPropertyName:
invocationId = JsonUtils.ReadAsString(reader, InvocationIdPropertyName);
break;
case StreamIdsPropertyName:
JsonUtils.CheckRead(reader);
if (reader.TokenType != JsonToken.StartArray)
{
throw new InvalidDataException($"Expected '{StreamIdsPropertyName}' to be of type {JTokenType.Array}.");
}
var newStreamIds = new List <string>();
reader.Read();
while (reader.TokenType != JsonToken.EndArray)
{
newStreamIds.Add(reader.Value?.ToString());
reader.Read();
}
streamIds = newStreamIds.ToArray();
break;
case TargetPropertyName:
target = JsonUtils.ReadAsString(reader, TargetPropertyName);
break;
case ErrorPropertyName:
error = JsonUtils.ReadAsString(reader, ErrorPropertyName);
break;
case AllowReconnectPropertyName:
allowReconnect = JsonUtils.ReadAsBoolean(reader, AllowReconnectPropertyName);
break;
case ResultPropertyName:
hasResult = true;
if (string.IsNullOrEmpty(invocationId))
{
JsonUtils.CheckRead(reader);
// 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);
if (!JsonUtils.ReadForType(reader, returnType))
{
throw new JsonReaderException("Unexpected end when reading JSON");
}
result = PayloadSerializer.Deserialize(reader, returnType);
}
break;
case ItemPropertyName:
JsonUtils.CheckRead(reader);
hasItem = true;
string id = null;
if (!string.IsNullOrEmpty(invocationId))
{
id = invocationId;
}
else
{
// If we don't have an id yet then we need to store it as a JToken to parse later
itemToken = JToken.Load(reader);
break;
}
try
{
var itemType = binder.GetStreamItemType(id);
item = PayloadSerializer.Deserialize(reader, itemType);
}
catch (Exception ex)
{
return(new StreamBindingFailureMessage(id, ExceptionDispatchInfo.Capture(ex)));
}
break;
case ArgumentsPropertyName:
JsonUtils.CheckRead(reader);
int initialDepth = reader.Depth;
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);
// Could be at any point in argument array JSON when an error is thrown
// Read until the end of the argument JSON array
while (reader.Depth == initialDepth && reader.TokenType == JsonToken.StartArray ||
reader.Depth > initialDepth)
{
JsonUtils.CheckRead(reader);
}
}
}
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)
{
// We weren't able to bind the arguments because they came before the 'target', so try to bind now that we've read everything.
try
{
var paramTypes = binder.GetParameterTypes(target);
arguments = BindArguments(argumentsToken, paramTypes);
}
catch (Exception ex)
{
argumentBindingException = ExceptionDispatchInfo.Capture(ex);
}
}
message = argumentBindingException != null
? new InvocationBindingFailureMessage(invocationId, target, argumentBindingException)
: BindInvocationMessage(invocationId, target, arguments, hasArguments, streamIds, binder);
}
break;
case HubProtocolConstants.StreamInvocationMessageType:
{
if (argumentsToken != null)
{
// We weren't able to bind the arguments because they came before the 'target', so try to bind now that we've read everything.
try
{
var paramTypes = binder.GetParameterTypes(target);
arguments = BindArguments(argumentsToken, paramTypes);
}
catch (Exception ex)
{
argumentBindingException = ExceptionDispatchInfo.Capture(ex);
}
}
message = argumentBindingException != null
? new InvocationBindingFailureMessage(invocationId, target, argumentBindingException)
: BindStreamInvocationMessage(invocationId, target, arguments, hasArguments, streamIds, binder);
}
break;
case HubProtocolConstants.StreamItemMessageType:
if (itemToken != null)
{
try
{
var itemType = binder.GetStreamItemType(invocationId);
item = itemToken.ToObject(itemType, PayloadSerializer);
}
catch (Exception ex)
{
message = new StreamBindingFailureMessage(invocationId, ExceptionDispatchInfo.Capture(ex));
break;
};
}
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, allowReconnect));
case null:
throw new InvalidDataException($"Missing required property '{TypePropertyName}'.");
default:
// Future protocol changes can add message types, old clients can ignore them
return(null);
}
return(ApplyHeaders(message, headers));
}
catch (JsonReaderException jrex)
{
throw new InvalidDataException("Error reading JSON.", jrex);
}
}
