initial draft

README.md

@@ -1,2 +1,14 @@
-State-Machines
-==============
+# Active State Machine Example
+Example Implementation of the Active State Machine pattern in .NET. 
+
+An Active State Machine is a state machine that performs transitions on a different thread as the code calling the state machine. 
+This allows for multiple threads calling it via a synchronization queue. 
+
+## Implementation Notes
+* This implementation takes use of the [Task Parallel Library](http://msdn.microsoft.com/en-us/library/dd460717.aspx) (TPL) to allow input from multiple threads. 
+* The state machine handles messages internally using [Reactive Extensions](https://rx.codeplex.com/) (Rx). 
+* [Fody](https://github.com/Fody/Fody) is used for Aspects
+* [NLog](http://nlog-project.org/) is used for logging
+
+## References
+1. [How to: Implement a Producer-Consumer Dataflow Pattern](http://msdn.microsoft.com/en-us/library/hh228601%28v=vs.110%29.aspx)

State-Machines/ActiveStateMachine/ActiveStateMachine.csproj

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+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{8C055B35-5FC5-4F9D-92C4-AFCBC2F43EF7}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>ActiveStateMachine</RootNamespace>
+    <AssemblyName>ActiveStateMachine</AssemblyName>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <NuGetPackageImportStamp>f16ffc44</NuGetPackageImportStamp>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <CodeAnalysisRuleSet>ManagedMinimumRules.ruleset</CodeAnalysisRuleSet>
+    <RunCodeAnalysis>true</RunCodeAnalysis>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="Anotar.NLog">
+      <HintPath>..\packages\Anotar.NLog.Fody.2.13.0\Lib\Anotar.NLog.dll</HintPath>
+      <Private>False</Private>
+    </Reference>
+    <Reference Include="NLog">
+      <HintPath>..\packages\NLog.3.1.0.0\lib\net45\NLog.dll</HintPath>
+    </Reference>
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+    <Reference Include="System.Reactive.Core">
+      <HintPath>..\packages\Rx-Core.2.2.5\lib\net45\System.Reactive.Core.dll</HintPath>
+    </Reference>
+    <Reference Include="System.Reactive.Interfaces">
+      <HintPath>..\packages\Rx-Interfaces.2.2.5\lib\net45\System.Reactive.Interfaces.dll</HintPath>
+    </Reference>
+    <Reference Include="System.Reactive.Linq">
+      <HintPath>..\packages\Rx-Linq.2.2.5\lib\net45\System.Reactive.Linq.dll</HintPath>
+    </Reference>
+    <Reference Include="System.Reactive.PlatformServices">
+      <HintPath>..\packages\Rx-PlatformServices.2.2.5\lib\net45\System.Reactive.PlatformServices.dll</HintPath>
+    </Reference>
+    <Reference Include="System.Threading.Tasks.Dataflow, Version=4.5.24.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <SpecificVersion>False</SpecificVersion>
+      <HintPath>..\packages\Microsoft.Tpl.Dataflow.4.5.24\lib\portable-net45+win8+wpa81\System.Threading.Tasks.Dataflow.dll</HintPath>
+    </Reference>
+    <Reference Include="System.Xml.Linq" />
+    <Reference Include="System.Data.DataSetExtensions" />
+    <Reference Include="Microsoft.CSharp" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Xml" />
+    <Reference Include="ToString">
+      <HintPath>..\packages\ToString.Fody.1.7.0.0\Lib\portable-net4+sl4+wp7+win8+MonoAndroid16+MonoTouch40\ToString.dll</HintPath>
+      <Private>False</Private>
+    </Reference>
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="Logging\MessageLogger.cs" />
+    <Compile Include="Messages\MessageReceiver.cs" />
+    <Compile Include="StateMachine.cs" />
+    <Compile Include="Messages\IMessage.cs" />
+    <Compile Include="StateMachineState.cs" />
+    <Compile Include="States\State.cs" />
+    <Compile Include="Transitions\TransitionAction.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="Messages\StateMachineCommandMessage.cs" />
+    <Compile Include="Messages\StateMachineExternalMessage.cs" />
+    <Compile Include="Messages\StateMachineInfo.cs" />
+    <Compile Include="Messages\StateMachineMessage.cs" />
+    <Compile Include="Messages\StateMachineNotificationMessage.cs" />
+    <Compile Include="Messages\StateMachineSystemMessage.cs" />
+    <Compile Include="Transitions\TransitionPrecondition.cs" />
+    <Compile Include="Transitions\Transition.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="packages.config" />
+  </ItemGroup>
+  <ItemGroup>
+    <Content Include="FodyWeavers.xml" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <Import Project="..\packages\Fody.1.26.2\build\Fody.targets" Condition="Exists('..\packages\Fody.1.26.2\build\Fody.targets')" />
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('..\packages\Fody.1.26.2\build\Fody.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Fody.1.26.2\build\Fody.targets'))" />
+  </Target>
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+       Other similar extension points exist, see Microsoft.Common.targets.
+  <Target Name="BeforeBuild">
+  </Target>
+  <Target Name="AfterBuild">
+  </Target>
+  -->
+</Project>

State-Machines/ActiveStateMachine/FodyWeavers.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<Weavers>
+  <Anotar.NLog />
+  <ToString />
+</Weavers>

State-Machines/ActiveStateMachine/Logging/MessageLogger.cs

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+using System;
+using ActiveStateMachine.Messages;
+using Anotar.NLog;
+
+namespace ActiveStateMachine.Logging
+{
+    public sealed class MessageLogger : IObserver<IMessage>
+    {
+        public MessageLogger(string name = "")
+        {
+            Name = name;
+        }
+
+        private string Name { get; }
+
+        public void OnNext(IMessage value)
+        {
+            var message = string.IsNullOrWhiteSpace(Name)
+                ? string.Format("Received message: {0}", value)
+                : string.Format("{0}: Received message: {1}", Name, value);
+
+            LogTo.Trace(message);
+        }
+
+        public void OnError(Exception error)
+        {
+            var message = string.IsNullOrWhiteSpace(Name)
+                ? "Encountered error."
+                : string.Format("{0}: Encountered error.", Name);
+
+            LogTo.ErrorException(message, error);
+        }
+
+        public void OnCompleted()
+        {
+            var message = string.IsNullOrWhiteSpace(Name)
+                ? "Source completed."
+                : string.Format("{0}: Source completed.", Name);
+
+            LogTo.Trace(message);
+        }
+    }
+}

State-Machines/ActiveStateMachine/Messages/IMessage.cs

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+using System;
+
+namespace ActiveStateMachine.Messages
+{
+    public interface IMessage
+    {
+        Guid Id { get; }
+        DateTime Timestamp { get; }
+        Version Version { get; }
+    }
+}

State-Machines/ActiveStateMachine/Messages/MessageReceiver.cs

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+using System;
+using System.Collections.Generic;
+using System.Reactive.Disposables;
+using System.Threading.Tasks;
+using System.Threading.Tasks.Dataflow;
+
+namespace ActiveStateMachine.Messages
+{
+    public sealed class MessageReceiver : IObservable<IMessage>
+    {
+        private List<IObserver<IMessage>> Observers { get; } = new List<IObserver<IMessage>>();
+
+        public async Task ReceiveAsync(ISourceBlock<IMessage> source)
+        {
+            while (await source.OutputAvailableAsync())
+            {
+                var message = source.Receive();
+                Observers.ForEach(observer => observer.OnNext(message));
+            }
+
+            Observers.ForEach(observer => observer.OnCompleted());
+        }
+
+        public IDisposable Subscribe(IObserver<IMessage> observer)
+        {
+            Observers.Add(observer);
+            return Disposable.Create(() => Observers.Remove(observer));
+        }
+    }
+}

State-Machines/ActiveStateMachine/Messages/StateMachineCommandMessage.cs

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+using System;
+
+namespace ActiveStateMachine.Messages
+{
+    [ToString]
+    public sealed class StateMachineCommandMessage : StateMachineMessage
+    {
+        public StateMachineCommandMessage(StateMachineInfo payload) 
+            : base(new Version(1,0))
+        {
+            Payload = payload;
+        }
+
+        public StateMachineInfo Payload { get; }
+    }
+}

State-Machines/ActiveStateMachine/Messages/StateMachineInfo.cs

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+namespace ActiveStateMachine.Messages
+{
+    [ToString]
+    public sealed class StateMachineInfo
+    {
+        public StateMachineInfo(string name, string eventInfo, string source, string target)
+        {
+            Name = name;
+            EventInfo = eventInfo;
+            Source = source;
+            Target = target;
+        }
+
+        public string Name { get; }
+        public string EventInfo { get; }
+        public string Source { get; }
+        public string Target { get; }
+    }
+}

State-Machines/ActiveStateMachine/Messages/StateMachineMessage.cs

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+using System;
+
+namespace ActiveStateMachine.Messages
+{
+    public abstract class StateMachineMessage : IMessage
+    {
+        protected StateMachineMessage(Version version)
+        {
+            Version = version;
+            Timestamp = DateTime.UtcNow;
+            Id = new Guid();
+        }
+
+        public Guid Id { get; }
+
+        public DateTime Timestamp { get; }
+
+        public Version Version { get; }
+    }
+}

State-Machines/ActiveStateMachine/Messages/StateMachineSystemMessage.cs

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+using System;
+
+namespace ActiveStateMachine.Messages
+{
+    [ToString]
+    public sealed class StateMachineSystemMessage : StateMachineMessage
+    {
+        public StateMachineSystemMessage(StateMachineInfo payload) 
+            : base(new Version(1,0))
+        {
+            Payload = payload;
+        }
+
+        public StateMachineInfo Payload { get; }
+    }
+}

State-Machines/ActiveStateMachine/Properties/AssemblyInfo.cs

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+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following 
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("ActiveStateMachine")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("ActiveStateMachine")]
+[assembly: AssemblyCopyright("Copyright ©  2014")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible 
+// to COM components.  If you need to access a type in this assembly from 
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("8c055b35-5fc5-4f9d-92c4-afcbc2f43ef7")]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version 
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers 
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]

State-Machines/ActiveStateMachine/StateMachine.cs

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+using System;
+using System.Collections.Generic;
+using System.Linq;
+using ActiveStateMachine.Messages;
+using ActiveStateMachine.States;
+using Anotar.NLog;
+
+namespace ActiveStateMachine
+{
+    public sealed class StateMachine : IObserver<IMessage>
+    {
+        public IEnumerable<State> PossibleStates { get; }
+        public State CurrentState => StateHistory.Last();
+        public IEnumerable<State> StateHistory { get; } = new List<State>();
+        public IEnumerable<IMessage> MessageHistory { get; } = new List<IMessage>();
+        public StateMachineState State { get; private set; }
+
+        public StateMachine(IEnumerable<State> possibleStates)
+        {
+            PossibleStates = possibleStates;
+            State = StateMachineState.Initialized;
+        }
+
+        [LogToErrorOnException]
+        public void Start()
+        {
+            if (State == StateMachineState.Initialized)
+                State = StateMachineState.Running;
+        }
+
+        [LogToErrorOnException]
+        public void OnNext(IMessage message)
+        {
+            if(State != StateMachineState.Running) return;
+
+            throw new NotImplementedException();
+        }
+
+        public void OnError(Exception error)
+        {
+            State = StateMachineState.Stopped;
+            LogTo.InfoException("Stopped because of an exception", error);
+        }
+
+        [LogToErrorOnException]
+        public void OnCompleted()
+        {
+            State = StateMachineState.Stopped;
+        }
+    }
+}