From 098036d49ad15ebd5fed452966e071de4f2de9e2 Mon Sep 17 00:00:00 2001
From: Keivan Beigi <kay.one@gmail.com>
Date: Tue, 30 Apr 2013 18:11:00 -0700
Subject: [PATCH] added new in memory cache.

---
 .../CacheTests/CachedFixture.cs               | 74 +++++++++++++++++++
 .../CacheTests/CachedManagerFixture.cs        | 33 +++++++++
 .../NzbDrone.Common.Test.csproj               |  2 +
 NzbDrone.Common/Cache/CacheManger.cs          | 22 ++++++
 NzbDrone.Common/Cache/Cached.cs               | 55 ++++++++++++++
 NzbDrone.Common/Cache/ICached.cs              | 13 ++++
 NzbDrone.Common/NzbDrone.Common.csproj        |  3 +
 7 files changed, 202 insertions(+)
 create mode 100644 NzbDrone.Common.Test/CacheTests/CachedFixture.cs
 create mode 100644 NzbDrone.Common.Test/CacheTests/CachedManagerFixture.cs
 create mode 100644 NzbDrone.Common/Cache/CacheManger.cs
 create mode 100644 NzbDrone.Common/Cache/Cached.cs
 create mode 100644 NzbDrone.Common/Cache/ICached.cs

diff --git a/NzbDrone.Common.Test/CacheTests/CachedFixture.cs b/NzbDrone.Common.Test/CacheTests/CachedFixture.cs
new file mode 100644
index 000000000..6396bcc50
--- /dev/null
+++ b/NzbDrone.Common.Test/CacheTests/CachedFixture.cs
@@ -0,0 +1,74 @@
+using FluentAssertions;
+using NUnit.Framework;
+using NzbDrone.Common.Cache;
+
+namespace NzbDrone.Common.Test.CacheTests
+{
+    [TestFixture]
+    public class CachedFixture
+    {
+        private Cached<string> _cachedString = new Cached<string>();
+        private Worker _worker;
+
+        [SetUp]
+        public void SetUp()
+        {
+            _cachedString = new Cached<string>();
+            _worker = new Worker();
+        }
+
+        [Test]
+        public void should_call_function_once()
+        {
+            _cachedString.Get("Test", _worker.GetString);
+            _cachedString.Get("Test", _worker.GetString);
+
+            _worker.HitCount.Should().Be(1);
+
+        }
+
+
+
+        [Test]
+        public void multiple_calls_should_return_same_result()
+        {
+            var first = _cachedString.Get("Test", _worker.GetString);
+            var second = _cachedString.Get("Test", _worker.GetString);
+
+            first.Should().Be(second);
+
+        }
+
+
+        [Test]
+        public void should_remove_value_from_set()
+        {
+            _cachedString.Get("Test", _worker.GetString);
+
+            _cachedString.Remove("Test");
+
+            _cachedString.Get("Test", _worker.GetString);
+
+
+            _worker.HitCount.Should().Be(2);
+
+        }
+
+        [Test]
+        public void remove_none_existing_should_break_things()
+        {
+            _cachedString.Remove("Test");
+        }
+    }
+
+    public class Worker
+    {
+        public int HitCount { get; private set; }
+
+        public string GetString()
+        {
+            HitCount++;
+            return "Hit count is " + HitCount;
+        }
+    }
+}
\ No newline at end of file
diff --git a/NzbDrone.Common.Test/CacheTests/CachedManagerFixture.cs b/NzbDrone.Common.Test/CacheTests/CachedManagerFixture.cs
new file mode 100644
index 000000000..60352d752
--- /dev/null
+++ b/NzbDrone.Common.Test/CacheTests/CachedManagerFixture.cs
@@ -0,0 +1,33 @@
+using System;
+using FluentAssertions;
+using NUnit.Framework;
+using NzbDrone.Common.Cache;
+
+namespace NzbDrone.Common.Test.CacheTests
+{
+    [TestFixture]
+    public class CachedManagerFixture
+    {
+        [Test]
+        public void should_return_proper_type_of_cache()
+        {
+            var result = CacheManger.GetCache<DateTime>(typeof(string));
+
+            result.Should().BeOfType<Cached<DateTime>>();
+        }
+
+
+        [Test]
+        public void multiple_calls_should_get_the_same_cache()
+        {
+            var result1 = CacheManger.GetCache<DateTime>(typeof(string));
+            var result2 = CacheManger.GetCache<DateTime>(typeof(string));
+
+            result1.Should().BeSameAs(result2);
+        }
+
+
+
+
+    }
+}
\ No newline at end of file
diff --git a/NzbDrone.Common.Test/NzbDrone.Common.Test.csproj b/NzbDrone.Common.Test/NzbDrone.Common.Test.csproj
index 04d816414..b52010006 100644
--- a/NzbDrone.Common.Test/NzbDrone.Common.Test.csproj
+++ b/NzbDrone.Common.Test/NzbDrone.Common.Test.csproj
@@ -78,6 +78,8 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="CacheTests\CachedManagerFixture.cs" />
+    <Compile Include="CacheTests\CachedFixture.cs" />
     <Compile Include="ConfigFileProviderTest.cs" />
     <Compile Include="EventingTests\MessageAggregatorCommandTests.cs" />
     <Compile Include="EventingTests\MessageAggregatorEventTests.cs" />
diff --git a/NzbDrone.Common/Cache/CacheManger.cs b/NzbDrone.Common/Cache/CacheManger.cs
new file mode 100644
index 000000000..97ace151d
--- /dev/null
+++ b/NzbDrone.Common/Cache/CacheManger.cs
@@ -0,0 +1,22 @@
+using System;
+using NzbDrone.Common.EnsureThat;
+
+namespace NzbDrone.Common.Cache
+{
+    public static class CacheManger
+    {
+        private static readonly ICached<object> Cache;
+
+        static CacheManger()
+        {
+            Cache = new Cached<object>();
+        }
+
+        public static ICached<T> GetCache<T>(Type type)
+        {
+            Ensure.That(() => type).IsNotNull();
+
+            return (ICached<T>)Cache.Get(type.FullName, () => new Cached<T>());
+        }
+    }
+}
\ No newline at end of file
diff --git a/NzbDrone.Common/Cache/Cached.cs b/NzbDrone.Common/Cache/Cached.cs
new file mode 100644
index 000000000..9ec11872f
--- /dev/null
+++ b/NzbDrone.Common/Cache/Cached.cs
@@ -0,0 +1,55 @@
+using System;
+using System.Collections.Concurrent;
+using NzbDrone.Common.EnsureThat;
+
+namespace NzbDrone.Common.Cache
+{
+    public class Cached<T> : ICached<T>
+    {
+        private readonly ConcurrentDictionary<string, T> _store;
+
+        public Cached()
+        {
+            _store = new ConcurrentDictionary<string, T>();
+        }
+
+        public void Set(string key, T value)
+        {
+            Ensure.That(() => key).IsNotNullOrWhiteSpace();
+            _store.TryAdd(key, value);
+        }
+
+        public T Get(string key, Func<T> function)
+        {
+            Ensure.That(() => key).IsNotNullOrWhiteSpace();
+
+            T value;
+
+            if (!_store.TryGetValue(key, out value))
+            {
+                value = function();
+                Set(key, value);
+            }
+
+            return value;
+        }
+
+        public bool ContainsKey(string key)
+        {
+            Ensure.That(() => key).IsNotNullOrWhiteSpace();
+            return _store.ContainsKey(key);
+        }
+
+        public void Clear()
+        {
+            _store.Clear();
+        }
+
+        public void Remove(string key)
+        {
+            Ensure.That(() => key).IsNotNullOrWhiteSpace();
+            T value;
+            _store.TryRemove(key, out value);
+        }
+    }
+}
\ No newline at end of file
diff --git a/NzbDrone.Common/Cache/ICached.cs b/NzbDrone.Common/Cache/ICached.cs
new file mode 100644
index 000000000..ab3142ac4
--- /dev/null
+++ b/NzbDrone.Common/Cache/ICached.cs
@@ -0,0 +1,13 @@
+using System;
+
+namespace NzbDrone.Common.Cache
+{
+    public interface ICached<T>
+    {
+        void Set(string key, T value);
+        T Get(string key, Func<T> function);
+        bool ContainsKey(string key);
+        void Clear();
+        void Remove(string key);
+    }
+}
\ No newline at end of file
diff --git a/NzbDrone.Common/NzbDrone.Common.csproj b/NzbDrone.Common/NzbDrone.Common.csproj
index 542afc695..3d74e8885 100644
--- a/NzbDrone.Common/NzbDrone.Common.csproj
+++ b/NzbDrone.Common/NzbDrone.Common.csproj
@@ -84,6 +84,9 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="ArchiveProvider.cs" />
+    <Compile Include="Cache\Cached.cs" />
+    <Compile Include="Cache\CacheManger.cs" />
+    <Compile Include="Cache\ICached.cs" />
     <Compile Include="ContainerBuilderBase.cs" />
     <Compile Include="EnsureThat\Ensure.cs" />
     <Compile Include="EnsureThat\EnsureBoolExtensions.cs" />