From 9331d4825601f93d2fcabfb32cdd87cd5a22d9b1 Mon Sep 17 00:00:00 2001
From: Ian Qvist <qvistian@gmail.com>
Date: Thu, 13 Apr 2017 16:32:04 +0200
Subject: [PATCH] Some work on #5

---
 .../Primitives/Optimization/IPoolable.cs      |  9 +++
 SourceFiles/Utils/Benchmark.cs                | 51 ++++++++++++
 SourceFiles/Utils/BenchmarkRun.cs             | 39 +++++++++
 SourceFiles/Utils/Pool.cs                     | 80 +++++++++++++++++++
 4 files changed, 179 insertions(+)
 create mode 100644 SourceFiles/Primitives/Optimization/IPoolable.cs
 create mode 100644 SourceFiles/Utils/Benchmark.cs
 create mode 100644 SourceFiles/Utils/BenchmarkRun.cs
 create mode 100644 SourceFiles/Utils/Pool.cs

diff --git a/SourceFiles/Primitives/Optimization/IPoolable.cs b/SourceFiles/Primitives/Optimization/IPoolable.cs
new file mode 100644
index 000000000..922f6e417
--- /dev/null
+++ b/SourceFiles/Primitives/Optimization/IPoolable.cs
@@ -0,0 +1,9 @@
+using System;
+
+namespace VelcroPhysics.Primitives.Optimization
+{
+    public interface IPoolable : IDisposable
+    {
+        void Reset();
+    }
+}
diff --git a/SourceFiles/Utils/Benchmark.cs b/SourceFiles/Utils/Benchmark.cs
new file mode 100644
index 000000000..889b30abf
--- /dev/null
+++ b/SourceFiles/Utils/Benchmark.cs
@@ -0,0 +1,51 @@
+using System.Collections.Generic;
+
+namespace VelcroPhysics.Utils
+{
+    public static class Benchmark
+    {
+        private static readonly Dictionary<string, long> _results = new Dictionary<string, long>();
+        private static readonly Pool<BenchmarkRun> _runPool = new Pool<BenchmarkRun>(1);
+
+        public static BenchmarkRun StartRun(string area)
+        {
+            BenchmarkRun run = _runPool.GetFromPool();
+            run.SetData(area);
+            return run;
+        }
+
+        public static void RecordResults(string area, long results)
+        {
+            if (!Settings.EnableDiagnostics)
+                return;
+
+            if (!_results.ContainsKey(area))
+                _results.Add(area, results);
+            else
+                _results[area] += results;
+        }
+
+        public static long ResetResults(string area)
+        {
+            if (!Settings.EnableDiagnostics)
+                return 0;
+
+            long oldVal = _results[area];
+            _results[area] = 0;
+            return oldVal;
+        }
+
+        public static long GetResults(string area)
+        {
+            if (!Settings.EnableDiagnostics)
+                return 0;
+
+            return _results.TryGetValue(area, out long value) ? value : 0;
+        }
+
+        internal static void ReturnToPool(BenchmarkRun run)
+        {
+            _runPool.ReturnToPool(run);
+        }
+    }
+}
diff --git a/SourceFiles/Utils/BenchmarkRun.cs b/SourceFiles/Utils/BenchmarkRun.cs
new file mode 100644
index 000000000..b50699818
--- /dev/null
+++ b/SourceFiles/Utils/BenchmarkRun.cs
@@ -0,0 +1,39 @@
+using System.Diagnostics;
+using VelcroPhysics.Primitives.Optimization;
+
+namespace VelcroPhysics.Utils
+{
+    public class BenchmarkRun : IPoolable
+    {
+        private string _area;
+        private readonly Stopwatch _stopwatch = new Stopwatch();
+        private bool _resultsRecorded;
+
+        public void SetData(string area)
+        {
+            _area = area;
+            _stopwatch.Start();
+        }
+
+        public void Dispose()
+        {
+            RecordResults();
+            Benchmark.ReturnToPool(this);
+        }
+
+        public void RecordResults()
+        {
+            if (_resultsRecorded)
+                return;
+
+            _stopwatch.Stop();
+            Benchmark.RecordResults(_area, _stopwatch.ElapsedTicks);
+            _resultsRecorded = true;
+        }
+
+        public void Reset()
+        {
+            _stopwatch.Reset();
+        }
+    }
+}
\ No newline at end of file
diff --git a/SourceFiles/Utils/Pool.cs b/SourceFiles/Utils/Pool.cs
new file mode 100644
index 000000000..4e2ff68dc
--- /dev/null
+++ b/SourceFiles/Utils/Pool.cs
@@ -0,0 +1,80 @@
+using System;
+using System.Collections.Generic;
+using VelcroPhysics.Primitives.Optimization;
+
+namespace VelcroPhysics.Utils
+{
+    public class Pool<T> where T : class, IPoolable, new()
+    {
+        private readonly Queue<T> _queue;
+
+        public Pool(int capacity, bool createInstances = true)
+        {
+            _queue = new Queue<T>(capacity);
+
+            if (createInstances)
+            {
+                for (int i = 0; i < capacity; i++)
+                {
+                    _queue.Enqueue(new T());
+                }
+            }
+        }
+
+        public T GetFromPool()
+        {
+            if (_queue.Count <= 0)
+                return new T();
+
+            T obj = _queue.Dequeue();
+            obj.Reset();
+            return obj;
+        }
+
+        public IEnumerable<T> GetManyFromPool(int count)
+        {
+            int diff = count - _queue.Count;
+
+            if (diff >= 0)
+            {
+                //We have all in queue
+                for (int i = 0; i < diff; i++)
+                {
+                    T obj = _queue.Dequeue();
+                    obj.Reset();
+                    yield return obj;
+                }
+            }
+            else
+            {
+                //We need to return what is in queue and then make more
+                for (int i = 0; i < _queue.Count; i++)
+                {
+                    T obj = _queue.Dequeue();
+                    obj.Reset();
+                    yield return obj;
+                }
+
+                int remaining = Math.Abs(diff);
+
+                for (int i = 0; i < remaining; i++)
+                {
+                    yield return new T();
+                }
+            }
+        }
+
+        public void ReturnToPool(T obj)
+        {
+            _queue.Enqueue(obj);
+        }
+
+        public void ReturnToPool(IEnumerable<T> objs)
+        {
+            foreach (T obj in objs)
+            {
+                _queue.Enqueue(obj);
+            }
+        }
+    }
+}