aspnetcore/src/Microsoft.AspNetCore.Signal.../Protocol/JsonHubProtocol.cs

737 lines
31 KiB
C#

// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
using System;
using System.Buffers;
using System.Collections.Generic;
using System.IO;
using System.Runtime.ExceptionServices;
using Microsoft.AspNetCore.Connections;
using Microsoft.AspNetCore.Internal;
using Microsoft.AspNetCore.SignalR.Internal;
using Microsoft.Extensions.Options;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Newtonsoft.Json.Serialization;
namespace Microsoft.AspNetCore.SignalR.Protocol
{
/// <summary>
/// Implements the SignalR Hub Protocol using JSON.
/// </summary>
public class JsonHubProtocol : IHubProtocol
{
private const string ResultPropertyName = "result";
private const string ItemPropertyName = "item";
private const string InvocationIdPropertyName = "invocationId";
private const string TypePropertyName = "type";
private const string ErrorPropertyName = "error";
private const string TargetPropertyName = "target";
private const string ArgumentsPropertyName = "arguments";
private const string HeadersPropertyName = "headers";
private static readonly string ProtocolName = "json";
private static readonly int ProtocolVersion = 1;
/// <summary>
/// Gets the serializer used to serialize invocation arguments and return values.
/// </summary>
public JsonSerializer PayloadSerializer { get; }
/// <summary>
/// Initializes a new instance of the <see cref="JsonHubProtocol"/> class.
/// </summary>
public JsonHubProtocol() : this(Options.Create(new JsonHubProtocolOptions()))
{
}
/// <summary>
/// Initializes a new instance of the <see cref="JsonHubProtocol"/> class.
/// </summary>
/// <param name="options">The options used to initialize the protocol.</param>
public JsonHubProtocol(IOptions<JsonHubProtocolOptions> options)
{
PayloadSerializer = JsonSerializer.Create(options.Value.PayloadSerializerSettings);
}
/// <inheritdoc />
public string Name => ProtocolName;
/// <inheritdoc />
public int Version => ProtocolVersion;
/// <inheritdoc />
public TransferFormat TransferFormat => TransferFormat.Text;
/// <inheritdoc />
public bool IsVersionSupported(int version)
{
return version == Version;
}
/// <inheritdoc />
public bool TryParseMessage(ref ReadOnlySequence<byte> input, IInvocationBinder binder, out HubMessage message)
{
if (!TextMessageParser.TryParseMessage(ref input, out var payload))
{
message = null;
return false;
}
var textReader = Utf8BufferTextReader.Get(payload);
try
{
message = ParseMessage(textReader, binder);
}
finally
{
Utf8BufferTextReader.Return(textReader);
}
return message != null;
}
/// <inheritdoc />
public void WriteMessage(HubMessage message, IBufferWriter<byte> output)
{
WriteMessageCore(message, output);
TextMessageFormatter.WriteRecordSeparator(output);
}
/// <inheritdoc />
public ReadOnlyMemory<byte> GetMessageBytes(HubMessage message)
{
return HubProtocolExtensions.GetMessageBytes(this, message);
}
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;
JArray argumentsToken = null;
ExceptionDispatchInfo argumentBindingException = null;
Dictionary<string, string> headers = null;
var completed = 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($"Missing required property '{TypePropertyName}'.");
}
type = messageType.Value;
break;
case InvocationIdPropertyName:
invocationId = JsonUtils.ReadAsString(reader, InvocationIdPropertyName);
break;
case TargetPropertyName:
target = JsonUtils.ReadAsString(reader, TargetPropertyName);
break;
case ErrorPropertyName:
error = JsonUtils.ReadAsString(reader, ErrorPropertyName);
break;
case ResultPropertyName:
hasResult = true;
if (string.IsNullOrEmpty(invocationId))
{
JsonUtils.CheckRead(reader);
// If we don't have an invocation id then we need to store it as a JToken so we can parse it later
resultToken = JToken.Load(reader);
}
else
{
// If we have an invocation id already we can parse the end result
var returnType = binder.GetReturnType(invocationId);
if (!JsonUtils.ReadForType(reader, returnType))
{
throw new JsonReaderException("Unexpected end when reading JSON");
}
result = PayloadSerializer.Deserialize(reader, returnType);
}
break;
case ItemPropertyName:
JsonUtils.CheckRead(reader);
hasItem = true;
if (string.IsNullOrEmpty(invocationId))
{
// If we don't have an invocation id then we need to store it as a JToken so we can parse it later
itemToken = JToken.Load(reader);
}
else
{
var returnType = binder.GetReturnType(invocationId);
item = PayloadSerializer.Deserialize(reader, returnType);
}
break;
case ArgumentsPropertyName:
JsonUtils.CheckRead(reader);
int initialDepth = reader.Depth;
if (reader.TokenType != JsonToken.StartArray)
{
throw new InvalidDataException($"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, 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, 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($"Missing required property '{TypePropertyName}'.");
default:
// Future protocol changes can add message types, old clients can ignore them
return null;
}
return ApplyHeaders(message, headers);
}
catch (JsonReaderException jrex)
{
throw new InvalidDataException("Error reading JSON.", jrex);
}
}
private Dictionary<string, string> ReadHeaders(JsonTextReader reader)
{
var headers = new Dictionary<string, string>(StringComparer.Ordinal);
if (reader.TokenType != JsonToken.StartObject)
{
throw new InvalidDataException($"Expected '{HeadersPropertyName}' to be of type {JTokenType.Object}.");
}
while (reader.Read())
{
switch (reader.TokenType)
{
case JsonToken.PropertyName:
var propertyName = reader.Value.ToString();
JsonUtils.CheckRead(reader);
if (reader.TokenType != JsonToken.String)
{
throw new InvalidDataException($"Expected header '{propertyName}' to be of type {JTokenType.String}.");
}
headers[propertyName] = reader.Value?.ToString();
break;
case JsonToken.Comment:
break;
case JsonToken.EndObject:
return headers;
}
}
throw new JsonReaderException("Unexpected end when reading message headers");
}
private void WriteMessageCore(HubMessage message, IBufferWriter<byte> stream)
{
var textWriter = Utf8BufferTextWriter.Get(stream);
try
{
using (var writer = JsonUtils.CreateJsonTextWriter(textWriter))
{
writer.WriteStartObject();
switch (message)
{
case InvocationMessage m:
WriteMessageType(writer, HubProtocolConstants.InvocationMessageType);
WriteHeaders(writer, m);
WriteInvocationMessage(m, writer);
break;
case StreamInvocationMessage m:
WriteMessageType(writer, HubProtocolConstants.StreamInvocationMessageType);
WriteHeaders(writer, m);
WriteStreamInvocationMessage(m, writer);
break;
case StreamItemMessage m:
WriteMessageType(writer, HubProtocolConstants.StreamItemMessageType);
WriteHeaders(writer, m);
WriteStreamItemMessage(m, writer);
break;
case CompletionMessage m:
WriteMessageType(writer, HubProtocolConstants.CompletionMessageType);
WriteHeaders(writer, m);
WriteCompletionMessage(m, writer);
break;
case CancelInvocationMessage m:
WriteMessageType(writer, HubProtocolConstants.CancelInvocationMessageType);
WriteHeaders(writer, m);
WriteCancelInvocationMessage(m, writer);
break;
case PingMessage _:
WriteMessageType(writer, HubProtocolConstants.PingMessageType);
break;
case CloseMessage m:
WriteMessageType(writer, HubProtocolConstants.CloseMessageType);
WriteCloseMessage(m, writer);
break;
default:
throw new InvalidOperationException($"Unsupported message type: {message.GetType().FullName}");
}
writer.WriteEndObject();
writer.Flush();
}
}
finally
{
Utf8BufferTextWriter.Return(textWriter);
}
}
private void WriteHeaders(JsonTextWriter writer, HubInvocationMessage message)
{
if (message.Headers != null && message.Headers.Count > 0)
{
writer.WritePropertyName(HeadersPropertyName);
writer.WriteStartObject();
foreach (var value in message.Headers)
{
writer.WritePropertyName(value.Key);
writer.WriteValue(value.Value);
}
writer.WriteEndObject();
}
}
private void WriteCompletionMessage(CompletionMessage message, JsonTextWriter writer)
{
WriteInvocationId(message, writer);
if (!string.IsNullOrEmpty(message.Error))
{
writer.WritePropertyName(ErrorPropertyName);
writer.WriteValue(message.Error);
}
else if (message.HasResult)
{
writer.WritePropertyName(ResultPropertyName);
PayloadSerializer.Serialize(writer, message.Result);
}
}
private void WriteCancelInvocationMessage(CancelInvocationMessage message, JsonTextWriter writer)
{
WriteInvocationId(message, writer);
}
private void WriteStreamItemMessage(StreamItemMessage message, JsonTextWriter writer)
{
WriteInvocationId(message, writer);
writer.WritePropertyName(ItemPropertyName);
PayloadSerializer.Serialize(writer, message.Item);
}
private void WriteInvocationMessage(InvocationMessage message, JsonTextWriter writer)
{
WriteInvocationId(message, writer);
writer.WritePropertyName(TargetPropertyName);
writer.WriteValue(message.Target);
WriteArguments(message.Arguments, writer);
}
private void WriteStreamInvocationMessage(StreamInvocationMessage message, JsonTextWriter writer)
{
WriteInvocationId(message, writer);
writer.WritePropertyName(TargetPropertyName);
writer.WriteValue(message.Target);
WriteArguments(message.Arguments, writer);
}
private void WriteCloseMessage(CloseMessage message, JsonTextWriter writer)
{
if (message.Error != null)
{
writer.WritePropertyName(ErrorPropertyName);
writer.WriteValue(message.Error);
}
}
private void WriteArguments(object[] arguments, JsonTextWriter writer)
{
writer.WritePropertyName(ArgumentsPropertyName);
writer.WriteStartArray();
foreach (var argument in arguments)
{
PayloadSerializer.Serialize(writer, argument);
}
writer.WriteEndArray();
}
private static void WriteInvocationId(HubInvocationMessage message, JsonTextWriter writer)
{
if (!string.IsNullOrEmpty(message.InvocationId))
{
writer.WritePropertyName(InvocationIdPropertyName);
writer.WriteValue(message.InvocationId);
}
}
private static void WriteMessageType(JsonTextWriter writer, int type)
{
writer.WritePropertyName(TypePropertyName);
writer.WriteValue(type);
}
private HubMessage BindCancelInvocationMessage(string invocationId)
{
if (string.IsNullOrEmpty(invocationId))
{
throw new InvalidDataException($"Missing required property '{InvocationIdPropertyName}'.");
}
return new CancelInvocationMessage(invocationId);
}
private HubMessage BindCompletionMessage(string invocationId, string error, object result, bool hasResult, IInvocationBinder binder)
{
if (string.IsNullOrEmpty(invocationId))
{
throw new InvalidDataException($"Missing required property '{InvocationIdPropertyName}'.");
}
if (error != null && hasResult)
{
throw new InvalidDataException("The 'error' and 'result' properties are mutually exclusive.");
}
if (hasResult)
{
return new CompletionMessage(invocationId, error, result, hasResult: true);
}
return new CompletionMessage(invocationId, error, result: null, hasResult: false);
}
private HubMessage BindStreamItemMessage(string invocationId, object item, bool hasItem, IInvocationBinder binder)
{
if (string.IsNullOrEmpty(invocationId))
{
throw new InvalidDataException($"Missing required property '{InvocationIdPropertyName}'.");
}
if (!hasItem)
{
throw new InvalidDataException($"Missing required property '{ItemPropertyName}'.");
}
return new StreamItemMessage(invocationId, item);
}
private HubMessage BindStreamInvocationMessage(string invocationId, string target, object[] arguments, bool hasArguments, IInvocationBinder binder)
{
if (string.IsNullOrEmpty(invocationId))
{
throw new InvalidDataException($"Missing required property '{InvocationIdPropertyName}'.");
}
if (!hasArguments)
{
throw new InvalidDataException($"Missing required property '{ArgumentsPropertyName}'.");
}
if (string.IsNullOrEmpty(target))
{
throw new InvalidDataException($"Missing required property '{TargetPropertyName}'.");
}
return new StreamInvocationMessage(invocationId, target, arguments);
}
private HubMessage BindInvocationMessage(string invocationId, string target, object[] arguments, bool hasArguments, IInvocationBinder binder)
{
if (string.IsNullOrEmpty(target))
{
throw new InvalidDataException($"Missing required property '{TargetPropertyName}'.");
}
if (!hasArguments)
{
throw new InvalidDataException($"Missing required property '{ArgumentsPropertyName}'.");
}
return new InvocationMessage(invocationId, target, arguments);
}
private bool ReadArgumentAsType(JsonTextReader reader, IReadOnlyList<Type> paramTypes, int paramIndex)
{
if (paramIndex < paramTypes.Count)
{
var paramType = paramTypes[paramIndex];
return JsonUtils.ReadForType(reader, paramType);
}
return reader.Read();
}
private object[] BindArguments(JsonTextReader reader, IReadOnlyList<Type> paramTypes)
{
object[] arguments = null;
var paramIndex = 0;
var argumentsCount = 0;
var paramCount = paramTypes.Count;
while (ReadArgumentAsType(reader, paramTypes, paramIndex))
{
if (reader.TokenType == JsonToken.EndArray)
{
if (argumentsCount != paramCount)
{
throw new InvalidDataException($"Invocation provides {argumentsCount} argument(s) but target expects {paramCount}.");
}
return arguments ?? Array.Empty<object>();
}
if (arguments == null)
{
arguments = new object[paramCount];
}
try
{
if (paramIndex < paramCount)
{
// Set all known arguments
arguments[paramIndex] = PayloadSerializer.Deserialize(reader, paramTypes[paramIndex]);
}
else
{
reader.Skip();
}
argumentsCount++;
paramIndex++;
}
catch (Exception ex)
{
throw new InvalidDataException("Error binding arguments. Make sure that the types of the provided values match the types of the hub method being invoked.", ex);
}
}
throw new JsonReaderException("Unexpected end when reading JSON");
}
private CloseMessage BindCloseMessage(string error)
{
// An empty string is still an error
if (error == null)
{
return CloseMessage.Empty;
}
var message = new CloseMessage(error);
return message;
}
private object[] BindArguments(JArray args, IReadOnlyList<Type> paramTypes)
{
var paramCount = paramTypes.Count;
var argCount = args.Count;
if (paramCount != argCount)
{
throw new InvalidDataException($"Invocation provides {argCount} argument(s) but target expects {paramCount}.");
}
if (paramCount == 0)
{
return Array.Empty<object>();
}
var arguments = new object[argCount];
try
{
for (var i = 0; i < paramCount; i++)
{
var paramType = paramTypes[i];
arguments[i] = args[i].ToObject(paramType, PayloadSerializer);
}
return arguments;
}
catch (Exception ex)
{
throw new InvalidDataException("Error binding arguments. Make sure that the types of the provided values match the types of the hub method being invoked.", ex);
}
}
private HubMessage ApplyHeaders(HubMessage message, Dictionary<string, string> headers)
{
if (headers != null && message is HubInvocationMessage invocationMessage)
{
invocationMessage.Headers = headers;
}
return message;
}
internal static JsonSerializerSettings CreateDefaultSerializerSettings()
{
return new JsonSerializerSettings { ContractResolver = new CamelCasePropertyNamesContractResolver() };
}
}
}