1 files changed, 103 insertions, 0 deletions
diff --git a/src/SMAPI/Framework/PerformanceCounter/PerformanceCounter.cs b/src/SMAPI/Framework/PerformanceCounter/PerformanceCounter.cs
new file mode 100644
index 00000000..04e0f5f5
--- /dev/null
+++ b/src/SMAPI/Framework/PerformanceCounter/PerformanceCounter.cs
@@ -0,0 +1,103 @@
+using System;
+using System.Diagnostics;
+using System.Linq;
+using Cyotek.Collections.Generic;
+using StardewModdingAPI.Framework.Utilities;
+
+namespace StardewModdingAPI.Framework.PerformanceCounter
+{
+    public class PerformanceCounter
+    {
+        private const int MAX_ENTRIES = 16384;
+
+        public string Name { get; }
+        public static Stopwatch Stopwatch = new Stopwatch();
+        public static long TotalNumEventsLogged;
+
+
+        private readonly CircularBuffer<PerformanceCounterEntry> _counter;
+
+        private PerformanceCounterEntry? PeakPerformanceCounterEntry;
+
+        public PerformanceCounter(string name)
+        {
+            this.Name = name;
+            this._counter = new CircularBuffer<PerformanceCounterEntry>(PerformanceCounter.MAX_ENTRIES);
+        }
+
+        public int GetAverageCallsPerSecond()
+        {
+            var x = this._counter.GroupBy(
+                p =>
+                    (int) p.EventTime.Subtract(
+                        new DateTime(1970, 1, 1)
+                    ).TotalSeconds);
+
+            return x.Last().Count();
+        }
+
+        public void Add(PerformanceCounterEntry entry)
+        {
+            PerformanceCounter.Stopwatch.Start();
+            this._counter.Put(entry);
+
+            if (this.PeakPerformanceCounterEntry == null)
+            {
+                this.PeakPerformanceCounterEntry = entry;
+            }
+            else
+            {
+                if (entry.Elapsed.TotalMilliseconds > this.PeakPerformanceCounterEntry.Value.Elapsed.TotalMilliseconds)
+                {
+                    this.PeakPerformanceCounterEntry = entry;
+                }
+            }
+
+            PerformanceCounter.Stopwatch.Stop();
+            PerformanceCounter.TotalNumEventsLogged++;
+        }
+
+        public PerformanceCounterEntry? GetPeak()
+        {
+            return this.PeakPerformanceCounterEntry;
+        }
+
+        public void ResetPeak()
+        {
+            this.PeakPerformanceCounterEntry = null;
+        }
+
+        public PerformanceCounterEntry? GetLastEntry()
+        {
+            if (this._counter.IsEmpty)
+            {
+                return null;
+            }
+            return this._counter.PeekLast();
+        }
+
+        public double GetAverage()
+        {
+            if (this._counter.IsEmpty)
+            {
+                return 0;
+            }
+
+            return this._counter.Average(p => p.Elapsed.TotalMilliseconds);
+        }
+
+        public double GetAverage(TimeSpan range)
+        {
+            if (this._counter.IsEmpty)
+            {
+                return 0;
+            }
+
+            var lastTime = this._counter.Max(x => x.EventTime);
+            var start = lastTime.Subtract(range);
+
+            var entries = this._counter.Where(x => (x.EventTime >= start) && (x.EventTime <= lastTime));
+            return entries.Average(x => x.Elapsed.TotalMilliseconds);
+        }
+    }
+}