From 3ad74da83f8cd252b5452e85dc5138f849fd4f46 Mon Sep 17 00:00:00 2001
From: Sebastian Stehle <sebastian@squidex.io>
Date: Thu, 6 Dec 2018 20:29:11 +0100
Subject: [PATCH] Made LRUCAche generic.

---
 .../Caching/LRUCache.cs                       | 44 +++++++------------
 .../Caching/LRUCacheItem.cs                   |  7 +--
 .../Caching/LRUCacheTests.cs                  |  2 +-
 3 files changed, 21 insertions(+), 32 deletions(-)

diff --git a/src/Squidex.Infrastructure/Caching/LRUCache.cs b/src/Squidex.Infrastructure/Caching/LRUCache.cs
index 4632d2ab0..7132eb1d3 100644
--- a/src/Squidex.Infrastructure/Caching/LRUCache.cs
+++ b/src/Squidex.Infrastructure/Caching/LRUCache.cs
@@ -9,23 +9,19 @@ using System.Collections.Generic;
 
 namespace Squidex.Infrastructure.Caching
 {
-    public sealed class LRUCache
+    public sealed class LRUCache<TKey, TValue>
     {
-        private readonly Dictionary<object, LinkedListNode<LRUCacheItem>> cacheMap = new Dictionary<object, LinkedListNode<LRUCacheItem>>();
-        private readonly LinkedList<LRUCacheItem> cacheHistory = new LinkedList<LRUCacheItem>();
+        private readonly Dictionary<TKey, LinkedListNode<LRUCacheItem<TKey, TValue>>> cacheMap = new Dictionary<TKey, LinkedListNode<LRUCacheItem<TKey, TValue>>>();
+        private readonly LinkedList<LRUCacheItem<TKey, TValue>> cacheHistory = new LinkedList<LRUCacheItem<TKey, TValue>>();
         private readonly int capacity;
 
         public LRUCache(int capacity)
         {
-            Guard.GreaterThan(capacity, 0, nameof(capacity));
-
             this.capacity = capacity;
         }
 
-        public bool Set(object key, object value)
+        public bool Set(TKey key, TValue value)
         {
-            Guard.NotNull(key, nameof(key));
-
             if (cacheMap.TryGetValue(key, out var node))
             {
                 node.Value.Value = value;
@@ -37,28 +33,24 @@ namespace Squidex.Infrastructure.Caching
 
                 return true;
             }
-            else
+
+            if (cacheMap.Count >= capacity)
             {
-                if (cacheMap.Count >= capacity)
-                {
-                    RemoveFirst();
-                }
+                RemoveFirst();
+            }
 
-                var cacheItem = new LRUCacheItem { Key = key, Value = value };
+            var cacheItem = new LRUCacheItem<TKey, TValue> { Key = key, Value = value };
 
-                node = new LinkedListNode<LRUCacheItem>(cacheItem);
+            node = new LinkedListNode<LRUCacheItem<TKey, TValue>>(cacheItem);
 
-                cacheMap.Add(key, node);
-                cacheHistory.AddLast(node);
+            cacheMap.Add(key, node);
+            cacheHistory.AddLast(node);
 
-                return false;
-            }
+            return false;
         }
 
-        public bool Remove(object key)
+        public bool Remove(TKey key)
         {
-            Guard.NotNull(key, nameof(key));
-
             if (cacheMap.TryGetValue(key, out var node))
             {
                 cacheMap.Remove(key);
@@ -70,10 +62,8 @@ namespace Squidex.Infrastructure.Caching
             return false;
         }
 
-        public bool TryGetValue(object key, out object value)
+        public bool TryGetValue(TKey key, out object value)
         {
-            Guard.NotNull(key, nameof(key));
-
             value = null;
 
             if (cacheMap.TryGetValue(key, out var node))
@@ -89,10 +79,8 @@ namespace Squidex.Infrastructure.Caching
             return false;
         }
 
-        public bool Contains(object key)
+        public bool Contains(TKey key)
         {
-            Guard.NotNull(key, nameof(key));
-
             return cacheMap.ContainsKey(key);
         }
 
diff --git a/src/Squidex.Infrastructure/Caching/LRUCacheItem.cs b/src/Squidex.Infrastructure/Caching/LRUCacheItem.cs
index ddf885afd..ff9cb3eef 100644
--- a/src/Squidex.Infrastructure/Caching/LRUCacheItem.cs
+++ b/src/Squidex.Infrastructure/Caching/LRUCacheItem.cs
@@ -9,9 +9,10 @@
 
 namespace Squidex.Infrastructure.Caching
 {
-    internal class LRUCacheItem
+    internal class LRUCacheItem<TKey, TValue>
     {
-        public object Key;
-        public object Value;
+        public TKey Key;
+
+        public TValue Value;
     }
 }
\ No newline at end of file
diff --git a/tests/Squidex.Infrastructure.Tests/Caching/LRUCacheTests.cs b/tests/Squidex.Infrastructure.Tests/Caching/LRUCacheTests.cs
index 4551fbe57..52e029193 100644
--- a/tests/Squidex.Infrastructure.Tests/Caching/LRUCacheTests.cs
+++ b/tests/Squidex.Infrastructure.Tests/Caching/LRUCacheTests.cs
@@ -11,7 +11,7 @@ namespace Squidex.Infrastructure.Caching
 {
     public class LRUCacheTests
     {
-        private readonly LRUCache sut = new LRUCache(10);
+        private readonly LRUCache<string, int> sut = new LRUCache<string, int>(10);
         private readonly string key = "Key";
 
         [Fact]