Using hashtables from pool instead of creating hashtable every time during sending any types of events.

Runtime/Scripts/Utilities/GA_HashtablePool.cs

@@ -0,0 +1,56 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+
+namespace GameAnalyticsSDK.Utilities
+{
+    public static class GA_HashtablePool
+    {
+        private static readonly Queue<Hashtable> _cache = new Queue<Hashtable>();
+
+        public static IDisposable Get(out Hashtable result)
+        {
+            Pop(out result);
+            return new Cached(result);
+        }
+
+        private static void Pop(out Hashtable result)
+        {
+            if (_cache.Count > 0)
+            {
+                result = _cache.Dequeue();
+            }
+            else
+            {
+                result = new Hashtable();
+            }
+        }
+
+        private static void Push(Hashtable hashtable)
+        {
+            if (hashtable == null)
+                return;
+
+            if (_cache.Contains(hashtable))
+                return;
+
+            hashtable.Clear();
+            _cache.Enqueue(hashtable);
+        }
+
+        private struct Cached : IDisposable
+        {
+            public Hashtable hashtable;
+
+            public Cached(Hashtable hashtable)
+            {
+                this.hashtable = hashtable;
+            }
+
+            public void Dispose()
+            {
+                Push(hashtable);
+            }
+        }
+    }
+}

Runtime/Scripts/Wrapper/GA_Wrapper.cs

@@ -693,15 +693,17 @@ public static string GetExternalUserId()
 
         private static string DictionaryToJsonString(IDictionary<string, object> dict)
         {
-            Hashtable table = new Hashtable();
-            if (dict != null)
+            using (GA_HashtablePool.Get(out var table))
             {
-                foreach (KeyValuePair<string, object> pair in dict)
+                if (dict != null)
                 {
-                    table.Add(pair.Key, pair.Value);
+                    foreach (KeyValuePair<string, object> pair in dict)
+                    {
+                        table.Add(pair.Key, pair.Value);
+                    }
                 }
+                return GA_MiniJSON.Serialize(table);
             }
-            return GA_MiniJSON.Serialize(table);
         }
 
         // TIMER FUNCTIONS