Initial commit of the performance counters

9 files changed, 477 insertions, 4 deletions

diff --git a/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/PerformanceCounterCommand.cs b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/PerformanceCounterCommand.cs
new file mode 100644
index 00000000..b7e56359
--- /dev/null
+++ b/src/SMAPI.Mods.ConsoleCommands/Framework/Commands/Other/PerformanceCounterCommand.cs
@@ -0,0 +1,14 @@
+namespace StardewModdingAPI.Mods.ConsoleCommands.Framework.Commands.Other
+{
+    internal class PerformanceCounterCommand: TrainerCommand
+    {
+        public PerformanceCounterCommand(string name, string description) : base("performance_counters", "Displays performance counters")
+        {
+        }
+
+        public override void Handle(IMonitor monitor, string command, ArgumentParser args)
+        {
+
+        }
+    }
+}
diff --git a/src/SMAPI/Constants.cs b/src/SMAPI/Constants.cs
index da2ee375..0923494c 100644
--- a/src/SMAPI/Constants.cs
+++ b/src/SMAPI/Constants.cs
@@ -55,6 +55,9 @@ namespace StardewModdingAPI
         /// <summary>The URL of the SMAPI home page.</summary>
         internal const string HomePageUrl = "https://smapi.io";
 
+        /// <summary>The URL of the SMAPI home page.</summary>
+        internal const string GamePerformanceCounterName = "-internal-";
+
         /// <summary>The absolute path to the folder containing SMAPI's internal files.</summary>
         internal static readonly string InternalFilesPath = Program.DllSearchPath;
 
@@ -100,7 +103,6 @@ namespace StardewModdingAPI
         /// <summary>The language code for non-translated mod assets.</summary>
         internal static LocalizedContentManager.LanguageCode DefaultLanguage { get; } = LocalizedContentManager.LanguageCode.en;
 
-
         /*********
         ** Internal methods
         *********/
diff --git a/src/SMAPI/Framework/Events/ManagedEvent.cs b/src/SMAPI/Framework/Events/ManagedEvent.cs
index 2afe7a03..9a5cb174 100644
--- a/src/SMAPI/Framework/Events/ManagedEvent.cs
+++ b/src/SMAPI/Framework/Events/ManagedEvent.cs
@@ -1,12 +1,15 @@
 using System;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Linq;
+using StardewModdingAPI.Framework.Utilities;
+using PerformanceCounter = StardewModdingAPI.Framework.Utilities.PerformanceCounter;
 
 namespace StardewModdingAPI.Framework.Events
 {
     /// <summary>An event wrapper which intercepts and logs errors in handler code.</summary>
     /// <typeparam name="TEventArgs">The event arguments type.</typeparam>
-    internal class ManagedEvent<TEventArgs>
+    internal class ManagedEvent<TEventArgs>: IPerformanceCounterEvent
     {
         /*********
         ** Fields
@@ -29,6 +32,38 @@ namespace StardewModdingAPI.Framework.Events
         /// <summary>The cached invocation list.</summary>
         private EventHandler<TEventArgs>[] CachedInvocationList;
 
+        public IDictionary<string, PerformanceCounter> PerformanceCounters { get; } = new Dictionary<string, PerformanceCounter>();
+
+        private readonly Stopwatch Stopwatch = new Stopwatch();
+
+        private long EventCallCount = 0;
+
+        private readonly DateTime StartDateTime = DateTime.Now;
+
+        public string GetEventName()
+        {
+            return this.EventName;
+        }
+
+        public double GetGameAverageExecutionTime()
+        {
+            if (this.PerformanceCounters.TryGetValue(Constants.GamePerformanceCounterName, out PerformanceCounter gameExecTime))
+            {
+                return gameExecTime.GetAverage();
+            }
+
+            return 0;
+        }
+
+        public double GetModsAverageExecutionTime()
+        {
+            return this.PerformanceCounters.Where(p => p.Key != Constants.GamePerformanceCounterName).Sum(p => p.Value.GetAverage());
+        }
+
+        public double GetAverageExecutionTime()
+        {
+            return this.PerformanceCounters.Sum(p => p.Value.GetAverage());
+        }
 
         /*********
         ** Public methods
@@ -64,6 +99,8 @@ namespace StardewModdingAPI.Framework.Events
         {
             this.Event += handler;
             this.AddTracking(mod, handler, this.Event?.GetInvocationList().Cast<EventHandler<TEventArgs>>());
+
+
         }
 
         /// <summary>Remove an event handler.</summary>
@@ -74,6 +111,18 @@ namespace StardewModdingAPI.Framework.Events
             this.RemoveTracking(handler, this.Event?.GetInvocationList().Cast<EventHandler<TEventArgs>>());
         }
 
+        public long GetAverageCallsPerSecond()
+        {
+            long runtimeInSeconds = (long)DateTime.Now.Subtract(this.StartDateTime).TotalSeconds;
+
+            if (runtimeInSeconds == 0)
+            {
+                return 0;
+            }
+
+            return this.EventCallCount / runtimeInSeconds;
+        }
+
         /// <summary>Raise the event and notify all handlers.</summary>
         /// <param name="args">The event arguments to pass.</param>
         public void Raise(TEventArgs args)
@@ -81,11 +130,31 @@ namespace StardewModdingAPI.Framework.Events
             if (this.Event == null)
                 return;
 
+            this.EventCallCount++;
+
             foreach (EventHandler<TEventArgs> handler in this.CachedInvocationList)
             {
                 try
                 {
+                    var performanceCounterEntry = new PerformanceCounterEntry()
+                    {
+                        EventTime = DateTime.Now
+                    };
+
+                    this.Stopwatch.Reset();
+                    this.Stopwatch.Start();
                     handler.Invoke(null, args);
+                    this.Stopwatch.Stop();
+                    performanceCounterEntry.Elapsed = this.Stopwatch.Elapsed;
+
+                    string modName = this.GetSourceMod(handler)?.DisplayName ?? Constants.GamePerformanceCounterName;
+
+                    if (!this.PerformanceCounters.ContainsKey(modName))
+                    {
+                        this.PerformanceCounters.Add(modName, new PerformanceCounter($"{modName}.{this.EventName}"));
+                    }
+                    this.PerformanceCounters[modName].Add(performanceCounterEntry);
+
                 }
                 catch (Exception ex)
                 {
diff --git a/src/SMAPI/Framework/SCore.cs b/src/SMAPI/Framework/SCore.cs
index c4841ece..6946a817 100644
--- a/src/SMAPI/Framework/SCore.cs
+++ b/src/SMAPI/Framework/SCore.cs
@@ -25,6 +25,7 @@ using StardewModdingAPI.Framework.ModLoading;
 using StardewModdingAPI.Framework.Patching;
 using StardewModdingAPI.Framework.Reflection;
 using StardewModdingAPI.Framework.Serialization;
+using StardewModdingAPI.Framework.Utilities;
 using StardewModdingAPI.Patches;
 using StardewModdingAPI.Toolkit;
 using StardewModdingAPI.Toolkit.Framework.Clients.WebApi;
@@ -33,6 +34,7 @@ using StardewModdingAPI.Toolkit.Serialization;
 using StardewModdingAPI.Toolkit.Utilities;
 using StardewValley;
 using Object = StardewValley.Object;
+using PerformanceCounter = StardewModdingAPI.Framework.Utilities.PerformanceCounter;
 using ThreadState = System.Threading.ThreadState;
 
 namespace StardewModdingAPI.Framework
@@ -77,6 +79,8 @@ namespace StardewModdingAPI.Framework
         /// <remarks>This is initialized after the game starts.</remarks>
         private readonly ModRegistry ModRegistry = new ModRegistry();
 
+        private HashSet<EventPerformanceCounterCategory> PerformanceCounterEvents = new HashSet<EventPerformanceCounterCategory>();
+
         /// <summary>Manages SMAPI events for mods.</summary>
         private readonly EventManager EventManager;
 
@@ -109,7 +113,7 @@ namespace StardewModdingAPI.Framework
                     "Oops! Steam achievements won't work because Steam isn't loaded. You can launch the game through Steam to fix that.",
 #endif
                 logLevel: LogLevel.Error
-            ), 
+            ),
 
             // save file not found error
             new ReplaceLogPattern(
@@ -162,6 +166,8 @@ namespace StardewModdingAPI.Framework
             };
             this.MonitorForGame = this.GetSecondaryMonitor("game");
             this.EventManager = new EventManager(this.Monitor, this.ModRegistry);
+            this.InitializePerformanceCounterEvents();
+
             SCore.DeprecationManager = new DeprecationManager(this.Monitor, this.ModRegistry);
 
             // redirect direct console output
@@ -200,6 +206,69 @@ namespace StardewModdingAPI.Framework
 #endif
         }
 
+        private void InitializePerformanceCounterEvents()
+        {
+            this.PerformanceCounterEvents = new HashSet<EventPerformanceCounterCategory>()
+            {
+                new EventPerformanceCounterCategory(this.EventManager.MenuChanged, false),
+
+                // Rendering Events
+                new EventPerformanceCounterCategory(this.EventManager.Rendering, true),
+                new EventPerformanceCounterCategory(this.EventManager.Rendered, true),
+                new EventPerformanceCounterCategory(this.EventManager.RenderingWorld, true),
+                new EventPerformanceCounterCategory(this.EventManager.RenderedWorld, true),
+                new EventPerformanceCounterCategory(this.EventManager.RenderingActiveMenu, true),
+                new EventPerformanceCounterCategory(this.EventManager.RenderedActiveMenu, true),
+                new EventPerformanceCounterCategory(this.EventManager.RenderingHud, true),
+                new EventPerformanceCounterCategory(this.EventManager.RenderedHud, true),
+
+                new EventPerformanceCounterCategory(this.EventManager.WindowResized, false),
+                new EventPerformanceCounterCategory(this.EventManager.GameLaunched, false),
+                new EventPerformanceCounterCategory(this.EventManager.UpdateTicking, true),
+                new EventPerformanceCounterCategory(this.EventManager.UpdateTicked, true),
+                new EventPerformanceCounterCategory(this.EventManager.OneSecondUpdateTicking, true),
+                new EventPerformanceCounterCategory(this.EventManager.OneSecondUpdateTicked, true),
+
+                new EventPerformanceCounterCategory(this.EventManager.SaveCreating, false),
+                new EventPerformanceCounterCategory(this.EventManager.SaveCreated, false),
+                new EventPerformanceCounterCategory(this.EventManager.Saving, false),
+                new EventPerformanceCounterCategory(this.EventManager.Saved, false),
+
+                new EventPerformanceCounterCategory(this.EventManager.DayStarted, false),
+                new EventPerformanceCounterCategory(this.EventManager.DayEnding, false),
+
+                new EventPerformanceCounterCategory(this.EventManager.TimeChanged, true),
+
+                new EventPerformanceCounterCategory(this.EventManager.ReturnedToTitle, false),
+
+                new EventPerformanceCounterCategory(this.EventManager.ButtonPressed, true),
+                new EventPerformanceCounterCategory(this.EventManager.ButtonReleased, true),
+                new EventPerformanceCounterCategory(this.EventManager.CursorMoved, true),
+                new EventPerformanceCounterCategory(this.EventManager.MouseWheelScrolled, true),
+
+                new EventPerformanceCounterCategory(this.EventManager.PeerContextReceived, true),
+                new EventPerformanceCounterCategory(this.EventManager.ModMessageReceived, true),
+                new EventPerformanceCounterCategory(this.EventManager.PeerDisconnected, true),
+                new EventPerformanceCounterCategory(this.EventManager.InventoryChanged, true),
+                new EventPerformanceCounterCategory(this.EventManager.LevelChanged, true),
+                new EventPerformanceCounterCategory(this.EventManager.Warped, true),
+
+                new EventPerformanceCounterCategory(this.EventManager.LocationListChanged, true),
+                new EventPerformanceCounterCategory(this.EventManager.BuildingListChanged, true),
+                new EventPerformanceCounterCategory(this.EventManager.LocationListChanged, true),
+                new EventPerformanceCounterCategory(this.EventManager.DebrisListChanged, true),
+                new EventPerformanceCounterCategory(this.EventManager.LargeTerrainFeatureListChanged, true),
+                new EventPerformanceCounterCategory(this.EventManager.NpcListChanged, true),
+                new EventPerformanceCounterCategory(this.EventManager.ObjectListChanged, true),
+                new EventPerformanceCounterCategory(this.EventManager.ChestInventoryChanged, true),
+                new EventPerformanceCounterCategory(this.EventManager.TerrainFeatureListChanged, true),
+                new EventPerformanceCounterCategory(this.EventManager.LoadStageChanged, false),
+                new EventPerformanceCounterCategory(this.EventManager.UnvalidatedUpdateTicking, true),
+                new EventPerformanceCounterCategory(this.EventManager.UnvalidatedUpdateTicked, true),
+
+            };
+        }
+
         /// <summary>Launch SMAPI.</summary>
         [HandleProcessCorruptedStateExceptions, SecurityCritical] // let try..catch handle corrupted state exceptions
         public void RunInteractively()
@@ -482,6 +551,19 @@ namespace StardewModdingAPI.Framework
             this.Monitor.Log("Type 'help' for help, or 'help <cmd>' for a command's usage", LogLevel.Info);
             this.GameInstance.CommandManager.Add(null, "help", "Lists command documentation.\n\nUsage: help\nLists all available commands.\n\nUsage: help <cmd>\n- cmd: The name of a command whose documentation to display.", this.HandleCommand);
             this.GameInstance.CommandManager.Add(null, "reload_i18n", "Reloads translation files for all mods.\n\nUsage: reload_i18n", this.HandleCommand);
+            this.GameInstance.CommandManager.Add(null, "performance_counters",
+                "Displays performance counters.\n\n"+
+                "Usage: performance_counters\n" +
+                "Shows the most important event invocation times\n\n"+
+                "Usage: performance_counters summary|sum [all|important|name]\n"+
+                "- summary or sum: Forces summary mode\n"+
+                "- all, important or name: Displays all event performance counters, only important ones, or a specific event by name (defaults to important)\n\n"+
+                "Usage: performance_counters [name] [threshold]\n"+
+                "Shows detailed performance counters for a specific event\n"+
+                "- name: The (partial) name of the event\n"+
+                "- threshold: The minimum avg execution time (ms) of the event\n"+
+                "", this.HandleCommand);
+            this.GameInstance.CommandManager.Add(null, "pc", "Alias for performance_counters", this.HandleCommand);
 
             // start handling command line input
             Thread inputThread = new Thread(() =>
@@ -1297,12 +1379,173 @@ namespace StardewModdingAPI.Framework
                     this.ReloadTranslations(this.ModRegistry.GetAll(contentPacks: false));
                     this.Monitor.Log("Reloaded translation files for all mods. This only affects new translations the mods fetch; if they cached some text, it may not be updated.", LogLevel.Info);
                     break;
-
+                case "performance_counters":
+                case "pc":
+                    this.DisplayPerformanceCounters(arguments.ToList());
+                    break;
                 default:
                     throw new NotSupportedException($"Unrecognized core SMAPI command '{name}'.");
             }
         }
 
+        /// <summary>Get an ASCII table to show tabular data in the console.</summary>
+        /// <typeparam name="T">The data type.</typeparam>
+        /// <param name="data">The data to display.</param>
+        /// <param name="header">The table header.</param>
+        /// <param name="getRow">Returns a set of fields for a data value.</param>
+        protected string GetTableString<T>(IEnumerable<T> data, string[] header, Func<T, string[]> getRow)
+        {
+            // get table data
+            int[] widths = header.Select(p => p.Length).ToArray();
+            string[][] rows = data
+                .Select(item =>
+                {
+                    string[] fields = getRow(item);
+                    if (fields.Length != widths.Length)
+                        throw new InvalidOperationException($"Expected {widths.Length} columns, but found {fields.Length}: {string.Join(", ", fields)}");
+
+                    for (int i = 0; i < fields.Length; i++)
+                        widths[i] = Math.Max(widths[i], fields[i].Length);
+
+                    return fields;
+                })
+                .ToArray();
+
+            // render fields
+            List<string[]> lines = new List<string[]>(rows.Length + 2)
+            {
+                header,
+                header.Select((value, i) => "".PadRight(widths[i], '-')).ToArray()
+            };
+            lines.AddRange(rows);
+
+            return string.Join(
+                Environment.NewLine,
+                lines.Select(line => string.Join(" | ", line.Select((field, i) => field.PadLeft(widths[i], ' ')).ToArray())
+                )
+            );
+        }
+
+        private void DisplayPerformanceCounters(IList<string> arguments)
+        {
+            bool showSummary = true;
+            bool showSummaryOnlyImportant = true;
+            string filterByName = null;
+
+            if (arguments.Any())
+            {
+                switch (arguments[0])
+                {
+                    case "summary":
+                        case "sum":
+                        showSummary = true;
+
+                        if (arguments.Count > 1)
+                        {
+                            switch (arguments[1].ToLower())
+                            {
+                                case "all":
+                                    showSummaryOnlyImportant = false;
+                                    break;
+                                case "important":
+                                    showSummaryOnlyImportant = true;
+                                    break;
+                                default:
+                                    filterByName = arguments[1];
+                                    break;
+                            }
+                        }
+                        break;
+                    default:
+                        showSummary = false;
+                        filterByName = arguments[0];
+                        break;
+
+                }
+            }
+            var lastMinute = TimeSpan.FromSeconds(60);
+
+            if (showSummary)
+            {
+                this.DisplayPerformanceCounterSummary(showSummaryOnlyImportant, filterByName);
+            }
+            else
+            {
+                var data = this.PerformanceCounterEvents.Where(p => p.Event.GetEventName().ToLowerInvariant().Contains(filterByName.ToLowerInvariant()));
+
+                foreach (var i in data)
+                {
+                    this.DisplayPerformanceCounter(i, lastMinute);
+                }
+            }
+
+            double avgTime = PerformanceCounter.Stopwatch.ElapsedMilliseconds / (double)PerformanceCounter.EventsLogged;
+            this.Monitor.Log($"Logged {PerformanceCounter.EventsLogged} events in {PerformanceCounter.Stopwatch.ElapsedMilliseconds}ms (avg {avgTime:F4}ms / event)");
+
+        }
+
+        private void DisplayPerformanceCounterSummary(bool showOnlyImportant, string eventNameFilter = null)
+        {
+            StringBuilder sb = new StringBuilder($"Performance Counter Summary:\n\n");
+
+            IEnumerable<EventPerformanceCounterCategory> data;
+
+            if (eventNameFilter != null)
+            {
+                data = this.PerformanceCounterEvents.Where(p => p.Event.GetEventName().ToLowerInvariant().Contains(eventNameFilter.ToLowerInvariant()));
+            }
+            else
+            {
+                if (showOnlyImportant)
+                {
+                    data = this.PerformanceCounterEvents.Where(p => p.IsImportant);
+                }
+                else
+                {
+                    data = this.PerformanceCounterEvents;
+                }
+            }
+
+
+            sb.AppendLine(this.GetTableString(
+                data: data,
+                header: new[] {"Event", "Avg Calls/s", "Avg Execution Time (Game)", "Avg Execution Time (Mods)", "Avg Execution Time (Game+Mods)"},
+                getRow: item => new[]
+                {
+                    item.Event.GetEventName(),
+                    item.Event.GetAverageCallsPerSecond().ToString(),
+                    item.Event.GetGameAverageExecutionTime().ToString("F2") + " ms",
+                    item.Event.GetModsAverageExecutionTime().ToString("F2") + " ms",
+                    item.Event.GetAverageExecutionTime().ToString("F2") + " ms"
+                }
+            ));
+
+            this.Monitor.Log(sb.ToString(), LogLevel.Info);
+        }
+
+        private void DisplayPerformanceCounter (EventPerformanceCounterCategory obj, TimeSpan averageInterval)
+        {
+            StringBuilder sb = new StringBuilder($"Performance Counter for {obj.Event.GetEventName()}:\n\n");
+
+            sb.AppendLine(this.GetTableString(
+                data: obj.Event.PerformanceCounters,
+                header: new[] {"Mod", $"Avg Execution Time over {(int)averageInterval.TotalSeconds}s", "Last Execution Time", "Peak Execution Time"},
+                getRow: item => new[]
+                {
+                    item.Key,
+                    item.Value.GetAverage(averageInterval).ToString("F2") + " ms" ?? "-",
+                    item.Value.GetLastEntry()?.Elapsed.TotalMilliseconds.ToString("F2") + " ms" ?? "-",
+                    item.Value.GetPeak()?.Elapsed.TotalMilliseconds.ToString("F2") + " ms" ?? "-",
+                }
+            ));
+
+            sb.AppendLine($"Average execution time (Game+Mods): {obj.Event.GetAverageExecutionTime():F2} ms");
+            sb.AppendLine($"Average execution time (Game only) : {obj.Event.GetGameAverageExecutionTime():F2} ms");
+            sb.AppendLine($"Average execution time (Mods only) : {obj.Event.GetModsAverageExecutionTime():F2} ms");
+
+            this.Monitor.Log(sb.ToString(), LogLevel.Info);
+        }
+
         /// <summary>Redirect messages logged directly to the console to the given monitor.</summary>
         /// <param name="gameMonitor">The monitor with which to log messages as the game.</param>
         /// <param name="message">The message to log.</param>
diff --git a/src/SMAPI/Framework/Utilities/EventPerformanceCounterCategory.cs b/src/SMAPI/Framework/Utilities/EventPerformanceCounterCategory.cs
new file mode 100644
index 00000000..14f74317
--- /dev/null
+++ b/src/SMAPI/Framework/Utilities/EventPerformanceCounterCategory.cs
@@ -0,0 +1,16 @@
+namespace StardewModdingAPI.Framework.Utilities
+{
+    public class EventPerformanceCounterCategory
+    {
+        public IPerformanceCounterEvent Event { get; }
+        public double MonitorThreshold { get; }
+        public bool IsImportant { get; }
+        public bool Monitor { get; }
+
+        public EventPerformanceCounterCategory(IPerformanceCounterEvent @event, bool isImportant)
+        {
+            this.Event = @event;
+            this.IsImportant = isImportant;
+        }
+    }
+}
diff --git a/src/SMAPI/Framework/Utilities/IPerformanceCounterEvent.cs b/src/SMAPI/Framework/Utilities/IPerformanceCounterEvent.cs
new file mode 100644
index 00000000..55302f90
--- /dev/null
+++ b/src/SMAPI/Framework/Utilities/IPerformanceCounterEvent.cs
@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+
+namespace StardewModdingAPI.Framework.Utilities
+{
+    public interface IPerformanceCounterEvent
+    {
+        string GetEventName();
+        long GetAverageCallsPerSecond();
+        IDictionary<string, PerformanceCounter> PerformanceCounters { get; }
+
+        double GetGameAverageExecutionTime();
+        double GetModsAverageExecutionTime();
+        double GetAverageExecutionTime();
+    }
+}
diff --git a/src/SMAPI/Framework/Utilities/PerformanceCounter.cs b/src/SMAPI/Framework/Utilities/PerformanceCounter.cs
new file mode 100644
index 00000000..c9ffcf5b
--- /dev/null
+++ b/src/SMAPI/Framework/Utilities/PerformanceCounter.cs
@@ -0,0 +1,102 @@
+using System;
+using System.Diagnostics;
+using System.Linq;
+using Cyotek.Collections.Generic;
+
+namespace StardewModdingAPI.Framework.Utilities
+{
+    public class PerformanceCounter
+    {
+        private const int MaxCount = 16384;
+
+        public string Name { get; }
+        public static Stopwatch Stopwatch = new Stopwatch();
+        public static long EventsLogged;
+
+
+        private readonly CircularBuffer<PerformanceCounterEntry> _counter;
+
+        private PerformanceCounterEntry? PeakPerformanceCounterEntry;
+
+        public PerformanceCounter(string name)
+        {
+            this.Name = name;
+            this._counter = new CircularBuffer<PerformanceCounterEntry>(PerformanceCounter.MaxCount);
+        }
+
+        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();
+            EventsLogged++;
+        }
+
+        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);
+        }
+    }
+}
diff --git a/src/SMAPI/Framework/Utilities/PerformanceCounterEntry.cs b/src/SMAPI/Framework/Utilities/PerformanceCounterEntry.cs
new file mode 100644
index 00000000..8e156a32
--- /dev/null
+++ b/src/SMAPI/Framework/Utilities/PerformanceCounterEntry.cs
@@ -0,0 +1,10 @@
+using System;
+
+namespace StardewModdingAPI.Framework.Utilities
+{
+    public struct PerformanceCounterEntry
+    {
+        public DateTime EventTime;
+        public TimeSpan Elapsed;
+    }
+}
diff --git a/src/SMAPI/SMAPI.csproj b/src/SMAPI/SMAPI.csproj
index 3bb73295..5e407c2c 100644
--- a/src/SMAPI/SMAPI.csproj
+++ b/src/SMAPI/SMAPI.csproj
@@ -16,6 +16,7 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="Cyotek.CircularBuffer" Version="1.0.2" />
     <PackageReference Include="LargeAddressAware" Version="1.0.3" />
     <PackageReference Include="Lib.Harmony" Version="1.2.0.1" />
     <PackageReference Include="Mono.Cecil" Version="0.11.1" />