refactor TasLagLog to allow for gaps in the history. Note that this is a breaking .tasproj format change currently

BizHawk.Client.Common/SavestateManager.cs

@@ -91,9 +91,9 @@ namespace BizHawk.Client.Common
 				if (Global.MovieSession.Movie.IsActive && Global.MovieSession.Movie is TasMovie)
 				{
 					bs.PutLump(BinaryStateLump.LagLog,
-						delegate(BinaryWriter bw)
+						delegate(TextWriter tw)
 						{
-							(Global.MovieSession.Movie as TasMovie).TasLagLog.Save(bw);
+							(Global.MovieSession.Movie as TasMovie).TasLagLog.Save(tw);
 						});
 				}
 			}
@@ -195,9 +195,9 @@ namespace BizHawk.Client.Common
 
 					if (Global.MovieSession.Movie.IsActive && Global.MovieSession.Movie is TasMovie)
 					{
-						bl.GetLump(BinaryStateLump.LagLog, false, delegate(BinaryReader br, long length)
+						bl.GetLump(BinaryStateLump.LagLog, false, delegate(TextReader tr)
 						{
-							((TasMovie)Global.MovieSession.Movie).TasLagLog.Load(br);
+							((TasMovie)Global.MovieSession.Movie).TasLagLog.Load(tr);
 						});
 					}
 				}

BizHawk.Client.Common/movie/tasproj/TasLagLog.cs

@@ -1,34 +1,30 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-
+using Newtonsoft.Json;
 using BizHawk.Emulation.Common.IEmulatorExtensions;
 
 namespace BizHawk.Client.Common
 {
 	public class TasLagLog
 	{
-		// TODO: Change this into a regular list.
+		private Dictionary<int, bool> _lagLog = new Dictionary<int, bool>();
-		private List<bool> _lagLog = new List<bool>();
+		private Dictionary<int, bool> _wasLag = new Dictionary<int, bool>();
-		private List<bool> _wasLag = new List<bool>();
 
 		public bool? this[int frame]
 		{
 			get
 			{
-				if (frame < _lagLog.Count)
+				bool lag;
+				var result = _lagLog.TryGetValue(frame, out lag);
+				if (result)
 				{
-					if (frame < 0)
+					return lag;
-					{
-						return null;
-					}
-
-					return _lagLog[frame];
 				}
 
-				if (frame == Global.Emulator.Frame && frame == _lagLog.Count)
+				// TODO: don't do this here, the calling code should decide if showing the current emulator state is the right decision
+				if (frame == Global.Emulator.Frame)
 				{
-					////LagLog[frame] = Global.Emulator.AsInputPollable().IsLagFrame; // Note: Side effects!
 					return Global.Emulator.AsInputPollable().IsLagFrame;
 				}
 
@@ -39,21 +35,10 @@ namespace BizHawk.Client.Common
 			{
 				if (!value.HasValue)
 				{
-					_lagLog.RemoveAt(frame);
+					_lagLog.Remove(frame);
 					return;
 				}
 
-				if (frame < 0)
-				{
-					return; // Nothing to do
-				}
-
-				if (frame > _lagLog.Count)
-				{
-					System.Diagnostics.Debug.Print($"Lag Log error. f{frame}, log: {_lagLog.Count}");
-					return; // Can this break anything?
-				}
-
 				bool wasValue;
 				if (frame < _lagLog.Count)
 				{
@@ -68,147 +53,83 @@ namespace BizHawk.Client.Common
 					wasValue = _wasLag[frame];
 				}
 
-				if (frame == _wasLag.Count)
+				_wasLag[frame] = wasValue;
-				{
-					_wasLag.Add(wasValue);
-				}
-				else
-				{
-					_wasLag[frame] = wasValue;
-				}
 
 				if (frame != 0)
 				{
 					_wasLag[frame - 1] = _lagLog[frame - 1];
 				}
 
-				if (frame >= _lagLog.Count)
+				_lagLog[frame] = value.Value;
-				{
-					_lagLog.Add(value.Value);
-				}
-				else
-				{
-					_lagLog[frame] = value.Value;
-				}
 			}
 		}
 
 		public void Clear()
 		{
+			// TODO: shouldn't _waslag get cleared too?
 			_lagLog.Clear();
 		}
 
 		public bool RemoveFrom(int frame)
 		{
-			if (_lagLog.Count > frame && frame >= 0)
+			var frames = _lagLog.Keys.Where(k => k > frame).ToList();
+			foreach (var f in frames)
 			{
-				_lagLog.RemoveRange(frame + 1, _lagLog.Count - frame - 1);
+				_lagLog.Remove(f);
-				return true;
 			}
 
-			return false;
+			return frames.Any();
 		}
 
 		public void RemoveHistoryAt(int frame)
 		{
-			_wasLag.RemoveAt(frame);
+			_wasLag.Remove(frame);
 		}
 
 		public void InsertHistoryAt(int frame, bool isLag)
 		{
-			// LagLog was invalidated when the frame was inserted
+			_lagLog[frame] = isLag;
-			if (frame <= _lagLog.Count)
+			_wasLag[frame] = isLag;
-			{
-				_lagLog.Insert(frame, isLag);
-			}
-
-			_wasLag.Insert(frame, isLag);
 		}
 
-		public void Save(BinaryWriter bw)
+		public void Save(TextWriter tw)
 		{
-			bw.Write((byte)1); // New saving format.
+			tw.WriteLine(JsonConvert.SerializeObject(_lagLog));
-			bw.Write(_lagLog.Count);
+			tw.WriteLine(JsonConvert.SerializeObject(_wasLag));
-			bw.Write(_wasLag.Count);
-			for (int i = 0; i < _lagLog.Count; i++)
-			{
-				bw.Write(_lagLog[i]);
-				bw.Write(_wasLag[i]);
-			}
-
-			for (int i = _lagLog.Count; i < _wasLag.Count; i++)
-			{
-				bw.Write(_wasLag[i]);
-			}
 		}
 
-		public void Load(BinaryReader br)
+		public void Load(TextReader tr)
 		{
-			_lagLog.Clear();
+			// TODO: support legacy lag logs that were List<bool>
-			_wasLag.Clear();
+			_lagLog = JsonConvert.DeserializeObject<Dictionary<int, bool>>(tr.ReadLine());
-			int formatVersion = br.ReadByte();
+			_wasLag = JsonConvert.DeserializeObject<Dictionary<int, bool>>(tr.ReadLine());
-			if (formatVersion == 0)
-			{
-				int length = (br.ReadByte() << 8) | formatVersion; // The first byte should be a part of length.
-				length = (br.ReadInt16() << 16) | length;
-				for (int i = 0; i < length; i++)
-				{
-					br.ReadInt32();
-					_lagLog.Add(br.ReadBoolean());
-					_wasLag.Add(_lagLog.Last());
-				}
-			}
-			else if (formatVersion == 1)
-			{
-				int length = br.ReadInt32();
-				int lenWas = br.ReadInt32();
-				for (int i = 0; i < length; i++)
-				{
-					_lagLog.Add(br.ReadBoolean());
-					_wasLag.Add(br.ReadBoolean());
-				}
-
-				for (int i = length; i < lenWas; i++)
-				{
-					_wasLag.Add(br.ReadBoolean());
-				}
-			}
 		}
 
 		public bool? History(int frame)
 		{
-			if (frame < _wasLag.Count)
+			bool wasLag;
+			var result = _wasLag.TryGetValue(frame, out wasLag);
+			if (result)
 			{
-				if (frame < 0)
+				return wasLag;
-				{
-					return null;
-				}
-
-				return _wasLag[frame];
 			}
 
 			return null;
 		}
 
-		public TasLagLog Clone()
-		{
-			return new TasLagLog
-			{
-				_lagLog = _lagLog.ToList(),
-				_wasLag = _wasLag.ToList()
-			};
-		}
-
 		public void FromLagLog(TasLagLog log)
 		{
-			_lagLog = log._lagLog.ToList();
+			_lagLog = log._lagLog.ToDictionary(kvp => kvp.Key, kvp => kvp.Value);
-			_wasLag = log._wasLag.ToList();
+			_wasLag = log._wasLag.ToDictionary(kvp => kvp.Key, kvp => kvp.Value);
 		}
 
 		public void StartFromFrame(int index)
 		{
-			_lagLog.RemoveRange(0, index);
+			for (int i = 0; i < index; i++)
-			_wasLag.RemoveRange(0, index);
+			{
+				_lagLog.Remove(i);
+				_wasLag.Remove(i);
+			}
 		}
 	}
 }

BizHawk.Client.Common/movie/tasproj/TasMovie.IO.cs

@@ -29,7 +29,7 @@ namespace BizHawk.Client.Common
 				// TasProj extras
 				bs.PutLump(BinaryStateLump.StateHistorySettings, tw => tw.WriteLine(_stateManager.Settings.ToString()));
 
-				bs.PutLump(BinaryStateLump.LagLog, (BinaryWriter bw) => _lagLog.Save(bw));
+				bs.PutLump(BinaryStateLump.LagLog, tw => _lagLog.Save(tw));
 				bs.PutLump(BinaryStateLump.Markers, tw => tw.WriteLine(Markers.ToString()));
 
 				if (StartsFromSavestate)
@@ -179,9 +179,9 @@ namespace BizHawk.Client.Common
 				}
 
 				// TasMovie enhanced information
-				bl.GetLump(BinaryStateLump.LagLog, false, delegate(BinaryReader br, long length)
+				bl.GetLump(BinaryStateLump.LagLog, false, delegate(TextReader tr)
 				{
-					_lagLog.Load(br);
+					_lagLog.Load(tr);
 				});
 
 				bl.GetLump(BinaryStateLump.StateHistorySettings, false, delegate(TextReader tr)