From eeebefee1bfcb37d16f7b4fcc4a8b5885faed3c7 Mon Sep 17 00:00:00 2001
From: Ryan Nowak <nowakra@gmail.com>
Date: Tue, 26 Sep 2017 10:17:48 -0700
Subject: [PATCH] Add data source

---
 .../DispatcherBase.cs                         |  8 +++--
 .../DispatcherDataSource.cs                   | 21 +++++++++++++
 .../SimpleDispatcherDataSource.cs             | 31 +++++++++++++++++++
 3 files changed, 57 insertions(+), 3 deletions(-)
 create mode 100644 src/Microsoft.AspNetCore.Dispatcher/DispatcherDataSource.cs
 create mode 100644 src/Microsoft.AspNetCore.Dispatcher/SimpleDispatcherDataSource.cs

diff --git a/src/Microsoft.AspNetCore.Dispatcher/DispatcherBase.cs b/src/Microsoft.AspNetCore.Dispatcher/DispatcherBase.cs
index e655828e01..e7cedc2abf 100644
--- a/src/Microsoft.AspNetCore.Dispatcher/DispatcherBase.cs
+++ b/src/Microsoft.AspNetCore.Dispatcher/DispatcherBase.cs
@@ -30,6 +30,8 @@ namespace Microsoft.AspNetCore.Dispatcher
             }
         }
 
+        public virtual DispatcherDataSource DataSource { get; set; }
+
         public virtual IList<Endpoint> Endpoints
         {
             get
@@ -56,11 +58,11 @@ namespace Microsoft.AspNetCore.Dispatcher
             }
         }
 
-        public IChangeToken ChangeToken => NullChangeToken.Singleton;
+        public IChangeToken ChangeToken => DataSource?.ChangeToken ?? NullChangeToken.Singleton;
 
-        IReadOnlyList<Address> IAddressCollectionProvider.Addresses => _addresses;
+        IReadOnlyList<Address> IAddressCollectionProvider.Addresses => ((IAddressCollectionProvider)DataSource)?.Addresses ?? _addresses ?? (IReadOnlyList<Address>)Array.Empty<Address>();
 
-        IReadOnlyList<Endpoint> IEndpointCollectionProvider.Endpoints => _endpoints;
+        IReadOnlyList<Endpoint> IEndpointCollectionProvider.Endpoints => ((IEndpointCollectionProvider)DataSource)?.Endpoints ?? _endpoints ?? (IReadOnlyList<Endpoint>)Array.Empty<Endpoint>();
 
         public virtual async Task InvokeAsync(HttpContext httpContext)
         {
diff --git a/src/Microsoft.AspNetCore.Dispatcher/DispatcherDataSource.cs b/src/Microsoft.AspNetCore.Dispatcher/DispatcherDataSource.cs
new file mode 100644
index 0000000000..2767e408dc
--- /dev/null
+++ b/src/Microsoft.AspNetCore.Dispatcher/DispatcherDataSource.cs
@@ -0,0 +1,21 @@
+// 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.Collections.Generic;
+using Microsoft.Extensions.Primitives;
+
+namespace Microsoft.AspNetCore.Dispatcher
+{
+    public abstract class DispatcherDataSource : IAddressCollectionProvider, IEndpointCollectionProvider
+    {
+        public abstract IChangeToken ChangeToken { get; }
+
+        protected abstract IReadOnlyList<Address> GetAddesses();
+
+        protected abstract IReadOnlyList<Endpoint> GetEndpoints();
+
+        IReadOnlyList<Address> IAddressCollectionProvider.Addresses => GetAddesses();
+
+        IReadOnlyList<Endpoint> IEndpointCollectionProvider.Endpoints => GetEndpoints();
+    }
+}
diff --git a/src/Microsoft.AspNetCore.Dispatcher/SimpleDispatcherDataSource.cs b/src/Microsoft.AspNetCore.Dispatcher/SimpleDispatcherDataSource.cs
new file mode 100644
index 0000000000..4fa5b6ff5a
--- /dev/null
+++ b/src/Microsoft.AspNetCore.Dispatcher/SimpleDispatcherDataSource.cs
@@ -0,0 +1,31 @@
+// 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.Collections.Generic;
+using Microsoft.Extensions.FileProviders;
+using Microsoft.Extensions.Primitives;
+
+namespace Microsoft.AspNetCore.Dispatcher
+{
+    public class SimpleDispatcherDataSource : DispatcherDataSource
+    {
+        private readonly List<Address> _addresses;
+        private readonly List<Endpoint> _endpoints; 
+
+        public SimpleDispatcherDataSource()
+        {
+            _addresses = new List<Address>();
+            _endpoints = new List<Endpoint>();
+        }
+
+        public override IChangeToken ChangeToken { get; } = NullChangeToken.Singleton;
+
+        public IList<Address> Addresses => _addresses;
+
+        public IList<Endpoint> Endpoint { get; } = new List<Endpoint>();
+
+        protected override IReadOnlyList<Address> GetAddesses() => _addresses;
+
+        protected override IReadOnlyList<Endpoint> GetEndpoints() => _endpoints;
+    }
+}