PM-3349 PM-3350 MAUI Migration Initial

src/Core/Controls/AvatarImageSourcePool.cs

@@ -0,0 +1,33 @@
+using System;
+using System.Collections.Concurrent;
+
+namespace Bit.App.Controls
+{
+    public interface IAvatarImageSourcePool
+    {
+        AvatarImageSource GetOrCreateAvatar(string userId, string name, string email, string color);
+    }
+
+    public class AvatarImageSourcePool : IAvatarImageSourcePool
+    {
+        private readonly ConcurrentDictionary<string, AvatarImageSource> _cache = new ConcurrentDictionary<string, AvatarImageSource>();
+
+        public AvatarImageSource GetOrCreateAvatar(string userId, string name, string email, string color)
+        {
+            var key = $"{userId}{name}{email}{color}";
+            if (!_cache.TryGetValue(key, out var avatar))
+            {
+                avatar = new AvatarImageSource(userId, name, email, color);
+                if (!_cache.TryAdd(key, avatar)
+                    &&
+                    !_cache.TryGetValue(key, out avatar)) // If add fails another thread created the avatar in between the first try get and the try add.
+                {
+                    // if add and get after fails, then something wrong is going on with this method.
+                    throw new InvalidOperationException("Something is wrong creating the avatar image");
+                }
+            }
+            return avatar;
+        }
+    }
+}
+