aspnetcore/src/Microsoft.AspNetCore.Signal.../HubConnection.cs

405 lines
16 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.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.AspNetCore.SignalR.Internal;
using Microsoft.AspNetCore.SignalR.Internal.Protocol;
using Microsoft.AspNetCore.Sockets;
using Microsoft.AspNetCore.Sockets.Client;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions;
using Newtonsoft.Json;
namespace Microsoft.AspNetCore.SignalR.Client
{
public class HubConnection
{
private readonly ILoggerFactory _loggerFactory;
private readonly ILogger _logger;
private readonly IConnection _connection;
private readonly IHubProtocol _protocol;
private readonly HubBinder _binder;
private HttpClient _httpClient;
private readonly object _pendingCallsLock = new object();
private readonly CancellationTokenSource _connectionActive = new CancellationTokenSource();
private readonly Dictionary<string, InvocationRequest> _pendingCalls = new Dictionary<string, InvocationRequest>();
private readonly ConcurrentDictionary<string, InvocationHandler> _handlers = new ConcurrentDictionary<string, InvocationHandler>();
private int _nextId = 0;
public event Action Connected
{
add { _connection.Connected += value; }
remove { _connection.Connected -= value; }
}
public event Action<Exception> Closed
{
add { _connection.Closed += value; }
remove { _connection.Closed -= value; }
}
public HubConnection(Uri url)
: this(new Connection(url), new JsonHubProtocol(new JsonSerializer()), null)
{ }
public HubConnection(Uri url, ILoggerFactory loggerFactory)
: this(new Connection(url), new JsonHubProtocol(new JsonSerializer()), loggerFactory)
{ }
// These are only really needed for tests now...
public HubConnection(IConnection connection, ILoggerFactory loggerFactory)
: this(connection, new JsonHubProtocol(new JsonSerializer()), loggerFactory)
{ }
public HubConnection(IConnection connection, IHubProtocol protocol, ILoggerFactory loggerFactory)
{
if (connection == null)
{
throw new ArgumentNullException(nameof(connection));
}
if (protocol == null)
{
throw new ArgumentNullException(nameof(protocol));
}
_connection = connection;
_binder = new HubBinder(this);
_protocol = protocol;
_loggerFactory = loggerFactory ?? NullLoggerFactory.Instance;
_logger = _loggerFactory.CreateLogger<HubConnection>();
_connection.Received += OnDataReceived;
_connection.Closed += Shutdown;
}
public Task StartAsync() => StartAsync(TransportType.All, httpClient: null);
public Task StartAsync(HttpClient httpClient) => StartAsync(TransportType.All, httpClient: httpClient);
public Task StartAsync(TransportType transportType) => StartAsync(transportType, httpClient: null);
public async Task StartAsync(TransportType transportType, HttpClient httpClient)
{
if (httpClient == null)
{
// We are creating the client so store it to be able to dispose
_httpClient = httpClient = new HttpClient();
}
await _connection.StartAsync(new DefaultTransportFactory(transportType, _loggerFactory, httpClient), httpClient);
}
public async Task StartAsync(ITransportFactory transportFactory, HttpClient httpClient)
{
await _connection.StartAsync(transportFactory, httpClient);
}
public async Task DisposeAsync()
{
await _connection.DisposeAsync();
_httpClient?.Dispose();
}
// TODO: Client return values/tasks?
public void On(string methodName, Type[] parameterTypes, Action<object[]> handler)
{
var invocationHandler = new InvocationHandler(parameterTypes, handler);
_handlers.AddOrUpdate(methodName, invocationHandler, (_, __) => invocationHandler);
}
public async Task<object> Invoke(string methodName, Type returnType, CancellationToken cancellationToken, params object[] args)
{
ThrowIfConnectionTerminated();
_logger.LogTrace("Preparing invocation of '{target}', with return type '{returnType}' and {argumentCount} args", methodName, returnType.AssemblyQualifiedName, args.Length);
// Create an invocation descriptor. Client invocations are always blocking
var invocationMessage = new InvocationMessage(GetNextId(), nonBlocking: false, target: methodName, arguments: args);
// I just want an excuse to use 'irq' as a variable name...
_logger.LogDebug("Registering Invocation ID '{invocationId}' for tracking", invocationMessage.InvocationId);
var irq = new InvocationRequest(cancellationToken, returnType, invocationMessage.InvocationId, _loggerFactory);
AddInvocation(irq);
// Trace the full invocation, but only if that logging level is enabled (because building the args list is a bit slow)
if (_logger.IsEnabled(LogLevel.Trace))
{
var argsList = string.Join(", ", args.Select(a => a.GetType().FullName));
_logger.LogTrace("Issuing Invocation '{invocationId}': {returnType} {methodName}({args})", invocationMessage.InvocationId, returnType.FullName, methodName, argsList);
}
try
{
var payload = await _protocol.WriteToArrayAsync(invocationMessage);
_logger.LogInformation("Sending Invocation '{invocationId}'", invocationMessage.InvocationId);
await _connection.SendAsync(payload, _protocol.MessageType, cancellationToken);
_logger.LogInformation("Sending Invocation '{invocationId}' complete", invocationMessage.InvocationId);
}
catch (Exception ex)
{
_logger.LogError(0, ex, "Sending Invocation '{invocationId}' failed", invocationMessage.InvocationId);
irq.Fail(ex);
TryRemoveInvocation(invocationMessage.InvocationId, out _);
}
// Return the completion task. It will be completed by ReceiveMessages when the response is received.
return await irq.Completion;
}
private void OnDataReceived(byte[] data, MessageType messageType)
{
var message = _protocol.ParseMessage(data, _binder);
InvocationRequest irq;
switch (message)
{
case InvocationMessage invocation:
if (_logger.IsEnabled(LogLevel.Trace))
{
var argsList = string.Join(", ", invocation.Arguments.Select(a => a.GetType().FullName));
_logger.LogTrace("Received Invocation '{invocationId}': {methodName}({args})", invocation.InvocationId, invocation.Target, argsList);
}
DispatchInvocation(invocation, _connectionActive.Token);
break;
case CompletionMessage completion:
if (!TryRemoveInvocation(completion.InvocationId, out irq))
{
_logger.LogWarning("Dropped unsolicited Completion message for invocation '{invocationId}'", completion.InvocationId);
return;
}
DispatchInvocationCompletion(completion, irq);
irq.Dispose();
break;
case StreamItemMessage streamItem:
// Complete the invocation with an error, we don't support streaming (yet)
if (!TryRemoveInvocation(streamItem.InvocationId, out irq))
{
_logger.LogWarning("Dropped unsolicited Stream Item message for invocation '{invocationId}'", streamItem.InvocationId);
return;
}
irq.Fail(new NotSupportedException("Streaming method results are not supported"));
break;
default:
throw new InvalidOperationException($"Unknown message type: {message.GetType().FullName}");
}
}
private void Shutdown(Exception ex = null)
{
_logger.LogTrace("Shutting down connection");
if (ex != null)
{
_logger.LogError(ex, "Connection is shutting down due to an error");
}
lock (_pendingCallsLock)
{
// We cancel inside the lock to make sure everyone who was part-way through registering an invocation
// completes. This also ensures that nobody will add things to _pendingCalls after we leave this block
// because everything that adds to _pendingCalls checks _connectionActive first (inside the _pendingCallsLock)
_connectionActive.Cancel();
foreach (var outstandingCall in _pendingCalls.Values)
{
_logger.LogTrace("Removing pending call {invocationId}", outstandingCall.InvocationId);
if (ex != null)
{
outstandingCall.Fail(ex);
}
outstandingCall.Dispose();
}
_pendingCalls.Clear();
}
}
private void DispatchInvocation(InvocationMessage invocation, CancellationToken cancellationToken)
{
// Find the handler
if (!_handlers.TryGetValue(invocation.Target, out InvocationHandler handler))
{
_logger.LogWarning("Failed to find handler for '{target}' method", invocation.Target);
return;
}
// TODO: Return values
// TODO: Dispatch to a sync context to ensure we aren't blocking this loop.
handler.Handler(invocation.Arguments);
}
private void DispatchInvocationCompletion(CompletionMessage completion, InvocationRequest irq)
{
_logger.LogTrace("Received Completion for Invocation #{invocationId}", completion.InvocationId);
if (irq.CancellationToken.IsCancellationRequested)
{
_logger.LogTrace("Cancelling dispatch of Completion message for Invocation {invocationId}. The invocation was cancelled.", irq.InvocationId);
}
else
{
if (!string.IsNullOrEmpty(completion.Error))
{
irq.Fail(new HubException(completion.Error));
}
else
{
irq.Complete(completion.Result);
}
}
}
private void ThrowIfConnectionTerminated()
{
if (_connectionActive.Token.IsCancellationRequested)
{
_logger.LogError("Invoke was called after the connection was terminated");
throw new InvalidOperationException("Connection has been terminated.");
}
}
private string GetNextId() => Interlocked.Increment(ref _nextId).ToString();
private void AddInvocation(InvocationRequest irq)
{
lock (_pendingCallsLock)
{
ThrowIfConnectionTerminated();
if (_pendingCalls.ContainsKey(irq.InvocationId))
{
_logger.LogCritical("Invocation ID '{invocationId}' is already in use.", irq.InvocationId);
throw new InvalidOperationException($"Invocation ID '{irq.InvocationId}' is already in use.");
}
else
{
_pendingCalls.Add(irq.InvocationId, irq);
}
}
}
private bool TryGetInvocation(string invocationId, out InvocationRequest irq)
{
lock (_pendingCallsLock)
{
ThrowIfConnectionTerminated();
return _pendingCalls.TryGetValue(invocationId, out irq);
}
}
private bool TryRemoveInvocation(string invocationId, out InvocationRequest irq)
{
lock (_pendingCallsLock)
{
ThrowIfConnectionTerminated();
if (_pendingCalls.TryGetValue(invocationId, out irq))
{
_pendingCalls.Remove(invocationId);
return true;
}
else
{
return false;
}
}
}
private class HubBinder : IInvocationBinder
{
private HubConnection _connection;
public HubBinder(HubConnection connection)
{
_connection = connection;
}
public Type GetReturnType(string invocationId)
{
if (!_connection._pendingCalls.TryGetValue(invocationId, out InvocationRequest irq))
{
_connection._logger.LogError("Unsolicited response received for invocation '{invocationId}'", invocationId);
return null;
}
return irq.ResultType;
}
public Type[] GetParameterTypes(string methodName)
{
if (!_connection._handlers.TryGetValue(methodName, out InvocationHandler handler))
{
_connection._logger.LogWarning("Failed to find handler for '{target}' method", methodName);
return Type.EmptyTypes;
}
return handler.ParameterTypes;
}
}
private struct InvocationHandler
{
public Action<object[]> Handler { get; }
public Type[] ParameterTypes { get; }
public InvocationHandler(Type[] parameterTypes, Action<object[]> handler)
{
Handler = handler;
ParameterTypes = parameterTypes;
}
}
private class InvocationRequest : IDisposable
{
private readonly TaskCompletionSource<object> _completionSource = new TaskCompletionSource<object>(TaskCreationOptions.RunContinuationsAsynchronously);
private readonly CancellationTokenRegistration _cancellationTokenRegistration;
private readonly ILogger _logger;
public Type ResultType { get; }
public CancellationToken CancellationToken { get; }
public string InvocationId { get; }
public Task<object> Completion => _completionSource.Task;
public InvocationRequest(CancellationToken cancellationToken, Type resultType, string invocationId, ILoggerFactory loggerFactory)
{
_logger = loggerFactory.CreateLogger<InvocationRequest>();
_cancellationTokenRegistration = cancellationToken.Register(() => _completionSource.TrySetCanceled());
InvocationId = invocationId;
CancellationToken = cancellationToken;
ResultType = resultType;
_logger.LogTrace("Invocation {invocationId} created", InvocationId);
}
public void Fail(Exception exception)
{
_logger.LogTrace("Invocation {invocationId} marked as failed", InvocationId);
_completionSource.TrySetException(exception);
}
public void Complete(object result)
{
_logger.LogTrace("Invocation {invocationId} marked as completed", InvocationId);
_completionSource.TrySetResult(result);
}
public void Dispose()
{
_logger.LogTrace("Invocation {invocationId} disposed", InvocationId);
// Just in case it hasn't already been completed
_completionSource.TrySetCanceled();
_cancellationTokenRegistration.Dispose();
}
}
}
}