simplified EventAggregator

This commit is contained in:
kay.one 2013-02-23 12:09:44 -08:00
parent b3c6db5997
commit 66972e5bc6
6 changed files with 187 additions and 194 deletions

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@ -0,0 +1,58 @@
using System.Collections.Generic;
using System.Linq;
using Moq;
using NUnit.Framework;
using NzbDrone.Common.Eventing;
using NzbDrone.Test.Common;
namespace NzbDrone.Common.Test.EventingTests
{
[TestFixture]
public class ServiceNameFixture : TestBase
{
private EventAggregator _aggregator;
[SetUp]
public void Setup()
{
_aggregator = new EventAggregator(TestLogger, null);
}
[Test]
public void should_publish_event_to_handlers()
{
var intHandler = new Mock<IHandle<int>>();
_aggregator = new EventAggregator(TestLogger, new List<IHandle> { intHandler.Object });
_aggregator.Publish(12);
intHandler.Verify(c => c.Handle(12), Times.Once());
}
[Test]
public void should_publish_to_more_than_one_handler()
{
var intHandler1 =new Mock<IHandle<int>>();
var intHandler2 = new Mock<IHandle<int>>();
_aggregator = new EventAggregator(TestLogger, new List<IHandle> { intHandler1.Object, intHandler2.Object });
_aggregator.Publish(12);
intHandler1.Verify(c => c.Handle(12), Times.Once());
intHandler2.Verify(c => c.Handle(12), Times.Once());
}
[Test]
public void should_not_publish_to_incompatible_handlers()
{
var intHandler = new Mock<IHandle<int>>();
var stringHandler = new Mock<IHandle<string>>();
_aggregator = new EventAggregator(TestLogger, new List<IHandle> { intHandler.Object, stringHandler.Object });
_aggregator.Publish(12);
intHandler.Verify(c => c.Handle(12), Times.Once());
stringHandler.Verify(c => c.Handle(It.IsAny<string>()), Times.Never());
}
}
}

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@ -86,6 +86,7 @@
</ItemGroup>
<ItemGroup>
<Compile Include="ConfigFileProviderTest.cs" />
<Compile Include="EventingTests\EventAggregatorTests.cs" />
<Compile Include="ReflectionExtensions.cs" />
<Compile Include="ReportingService_ReportParseError_Fixture.cs" />
<Compile Include="PathExtentionFixture.cs" />

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@ -1,173 +1,28 @@
using System;
using System.Collections.Generic;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
//From http://caliburnmicro.codeplex.com/
using NLog;
namespace NzbDrone.Common.Eventing
{
/// <summary>
/// Enables loosely-coupled publication of and subscription to events.
/// </summary>
public class EventAggregator : IEventAggregator
{
readonly List<Handler> handlers = new List<Handler>();
private readonly Logger _logger;
private readonly IEnumerable<IHandle> _handlers;
/// <summary>
/// The default thread marshaller used for publication;
/// </summary>
public static Action<Action> DefaultPublicationThreadMarshaller = action => action();
/// <summary>
/// Processing of handler results on publication thread.
/// </summary>
public static Action<object, object> HandlerResultProcessing = (target, result) => { };
/// <summary>
/// Initializes a new instance of the <see cref = "EventAggregator" /> class.
/// </summary>
public EventAggregator()
public EventAggregator(Logger logger, IEnumerable<IHandle> handlers)
{
PublicationThreadMarshaller = DefaultPublicationThreadMarshaller;
_logger = logger;
_handlers = handlers;
}
/// <summary>
/// Gets or sets the default publication thread marshaller.
/// </summary>
/// <value>
/// The default publication thread marshaller.
/// </value>
public Action<System.Action> PublicationThreadMarshaller { get; set; }
/// <summary>
/// Subscribes an instance to all events declared through implementations of <see cref = "IHandle{T}" />
/// </summary>
/// <param name = "instance">The instance to subscribe for event publication.</param>
public virtual void Subscribe(object instance)
public void Publish<TEvent>(TEvent message)
{
lock (handlers)
_logger.Trace("Publishing {0}", message.GetType().Name);
foreach (var handler in _handlers.OfType<IHandle<TEvent>>())
{
if (handlers.Any(x => x.Matches(instance)))
{
return;
}
handlers.Add(new Handler(instance));
}
}
/// <summary>
/// Unsubscribes the instance from all events.
/// </summary>
/// <param name = "instance">The instance to unsubscribe.</param>
public virtual void Unsubscribe(object instance)
{
lock (handlers)
{
var found = handlers.FirstOrDefault(x => x.Matches(instance));
if (found != null)
{
handlers.Remove(found);
}
}
}
/// <summary>
/// Publishes a message.
/// </summary>
/// <param name = "message">The message instance.</param>
/// <remarks>
/// Does not marshall the the publication to any special thread by default.
/// </remarks>
public virtual void Publish(object message)
{
Publish(message, PublicationThreadMarshaller);
}
/// <summary>
/// Publishes a message.
/// </summary>
/// <param name = "message">The message instance.</param>
/// <param name = "marshal">Allows the publisher to provide a custom thread marshaller for the message publication.</param>
public virtual void Publish(object message, Action<System.Action> marshal)
{
Handler[] toNotify;
lock (handlers)
{
toNotify = handlers.ToArray();
}
marshal(() =>
{
var messageType = message.GetType();
var dead = toNotify
.Where(handler => !handler.Handle(messageType, message))
.ToList();
if (dead.Any())
{
lock (handlers)
{
foreach (var item in dead)
{
handlers.Remove(item);
}
}
}
});
}
class Handler
{
readonly WeakReference reference;
readonly Dictionary<Type, MethodInfo> supportedHandlers = new Dictionary<Type, MethodInfo>();
public Handler(object handler)
{
reference = new WeakReference(handler);
var interfaces = handler.GetType().GetInterfaces()
.Where(x => typeof(IHandle).IsAssignableFrom(x) && x.IsGenericType);
foreach (var @interface in interfaces)
{
var type = @interface.GetGenericArguments()[0];
var method = @interface.GetMethod("Handle");
supportedHandlers[type] = method;
}
}
public bool Matches(object instance)
{
return reference.Target == instance;
}
public bool Handle(Type messageType, object message)
{
var target = reference.Target;
if (target == null)
{
return false;
}
foreach (var pair in supportedHandlers)
{
if (pair.Key.IsAssignableFrom(messageType))
{
var result = pair.Value.Invoke(target, new[] { message });
if (result != null)
{
HandlerResultProcessing(target, result);
}
return true;
}
}
return true;
_logger.Trace("{0} => {1}", message.GetType().Name, handler.GetType().Name);
handler.Handle(message);
}
}
}

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@ -4,44 +4,10 @@ using System.Linq;
namespace NzbDrone.Common.Eventing
{
/// <summary>
/// Enables loosely-coupled publication of and subscription to events.
/// Enables loosely-coupled publication of events.
/// </summary>
public interface IEventAggregator
{
/// <summary>
/// Gets or sets the default publication thread marshaller.
/// </summary>
/// <value>
/// The default publication thread marshaller.
/// </value>
Action<Action> PublicationThreadMarshaller { get; set; }
/// <summary>
/// Subscribes an instance to all events declared through implementations of <see cref = "IHandle{T}" />
/// </summary>
/// <param name = "instance">The instance to subscribe for event publication.</param>
void Subscribe(object instance);
/// <summary>
/// Unsubscribes the instance from all events.
/// </summary>
/// <param name = "instance">The instance to unsubscribe.</param>
void Unsubscribe(object instance);
/// <summary>
/// Publishes a message.
/// </summary>
/// <param name = "message">The message instance.</param>
/// <remarks>
/// Uses the default thread marshaller during publication.
/// </remarks>
void Publish(object message);
/// <summary>
/// Publishes a message.
/// </summary>
/// <param name = "message">The message instance.</param>
/// <param name = "marshal">Allows the publisher to provide a custom thread marshaller for the message publication.</param>
void Publish(object message, Action<System.Action> marshal);
void Publish<TEvent>(TEvent message);
}
}

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@ -0,0 +1,110 @@
using System;
using System.Diagnostics;
using System.Linq;
using FluentAssertions;
using NLog;
using NUnit.Framework;
using NzbDrone.Core.Tv;
using NzbDrone.Core.Instrumentation;
using NzbDrone.Core.Test.Framework;
using NzbDrone.Test.Common;
namespace NzbDrone.Core.Test.InstrumentationTests
{
[TestFixture]
public class DatabaseTargetFixture : ObjectDbTest<DatabaseTarget, Log>
{
string _loggerName;
private static string _uniqueMessage;
Logger _logger;
[SetUp]
public void Setup()
{
Mocker.Resolve<ILogRepository, LogRepository>();
Mocker.Resolve<DatabaseTarget>().Register();
_logger = LogManager.GetCurrentClassLogger();
_loggerName = _logger.Name.Replace("NzbDrone.","");
_uniqueMessage = "Unique message: " + Guid.NewGuid().ToString();
}
[Test]
public void write_log()
{
_logger.Info(_uniqueMessage);
StoredModel.Message.Should().Be(_uniqueMessage);
VerifyLog(StoredModel, LogLevel.Info);
}
[Test]
public void write_long_log()
{
var message = String.Empty;
for (int i = 0; i < 100; i++)
{
message += Guid.NewGuid();
}
_logger.Info(message);
StoredModel.Message.Should().HaveLength(message.Length);
StoredModel.Message.Should().Be(message);
VerifyLog(StoredModel, LogLevel.Info);
}
[Test]
public void write_log_exception()
{
var ex = new InvalidOperationException("Fake Exception");
_logger.ErrorException(_uniqueMessage, ex);
VerifyLog(StoredModel, LogLevel.Error);
StoredModel.Message.Should().Be(_uniqueMessage + ": " + ex.Message);
StoredModel.ExceptionType.Should().Be(ex.GetType().ToString());
StoredModel.Exception.Should().Be(ex.ToString());
ExceptionVerification.ExpectedErrors(1);
}
[Test]
public void exception_log_with_no_message_should_use_exceptions_message()
{
var ex = new InvalidOperationException("Fake Exception");
_uniqueMessage = String.Empty;
_logger.ErrorException(_uniqueMessage, ex);
StoredModel.Message.Should().Be(ex.Message);
VerifyLog(StoredModel, LogLevel.Error);
ExceptionVerification.ExpectedErrors(1);
}
[Test]
public void null_string_as_arg_should_not_fail()
{
var epFile = new EpisodeFile();
_logger.Trace("File {0} no longer exists on disk. removing from database.", epFile.Path);
epFile.Path.Should().BeNull();
}
private void VerifyLog(Log logItem, LogLevel level)
{
logItem.Time.Should().BeWithin(TimeSpan.FromSeconds(2));
logItem.Logger.Should().Be(_loggerName);
logItem.Level.Should().Be(level.Name);
logItem.Method.Should().Be(new StackTrace().GetFrame(1).GetMethod().Name);
_logger.Name.Should().EndWith(logItem.Logger);
}
}
}

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@ -7,6 +7,9 @@ namespace NzbDrone.Test.Common
{
public abstract class LoggingTest
{
protected Logger TestLogger = LogManager.GetLogger("TestLogger");
protected static void InitLogging()
{
if (LogManager.Configuration == null || LogManager.Configuration is XmlLoggingConfiguration)