Move ImageLoader to Wox.Infrastructure, part 1

Wox.Infrastructure/Image/ImageCache.cs

@@ -0,0 +1,35 @@
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.Linq;
+using Wox.Infrastructure.Storage;
+
+namespace Wox.ImageLoader
+{
+    [Serializable]
+    public class ImageCache
+    {
+        private const int MaxCached = 200;
+        public ConcurrentDictionary<string, int> TopUsedImages = new ConcurrentDictionary<string, int>();
+
+        public void Add(string path)
+        {
+            if (TopUsedImages.ContainsKey(path))
+            {
+                TopUsedImages[path] = TopUsedImages[path] + 1;
+            }
+            else
+            {
+                TopUsedImages[path] = 1;
+            }
+
+            if (TopUsedImages.Count > MaxCached)
+            {
+                var images = TopUsedImages.OrderByDescending(o => o.Value)
+                                          .Take(MaxCached)
+                                          .ToDictionary(i => i.Key, i => i.Value);
+                TopUsedImages = new ConcurrentDictionary<string, int>(images);
+            }
+        }
+    }
+}