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support non-delta rewind states

This commit is contained in:
zeromus 2013-07-27 23:13:27 +00:00
parent c0e2a2bbb7
commit ba210103c1
1 changed files with 64 additions and 45 deletions
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109
BizHawk.MultiClient/Rewind.cs
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@ -8,9 +8,11 @@ namespace BizHawk.MultiClient
{
//adelikat: change the way this is constructed to control whether its on disk or in memory
private readonly StreamBlobDatabase RewindBuf = new StreamBlobDatabase(true,128*1024*1024);
private byte[] LastState;
private bool RewindImpossible;
private int RewindFrequency = 1;
private bool RewindDeltaEnable = false;
/// <summary>
/// Manages a ring buffer of storage which can continually chow its own tail to keep growing forward.
@ -250,13 +252,18 @@ namespace BizHawk.MultiClient
DoRewindSettings();
}
// Otherwise, it's not the first frame, so build a delta.
//log a frame
if (LastState != null && Global.Emulator.Frame % RewindFrequency == 0)
{
if (LastState.Length <= 0x10000)
CaptureRewindState64K();
else
CaptureRewindStateLarge();
if (RewindDeltaEnable)
{
if (LastState.Length <= 0x10000)
CaptureRewindStateDelta(true);
else
CaptureRewindStateDelta(false);
}
else CaptureRewindStateNonDelta();
}
}
@ -285,17 +292,37 @@ namespace BizHawk.MultiClient
SetRewindParams(Global.Config.RewindEnabledMedium,Global.Config.RewindFrequencyMedium);
else
SetRewindParams(Global.Config.RewindEnabledSmall, Global.Config.RewindFrequencySmall);
//adelikat: placeholder for plucking from config
RewindDeltaEnable = true;
}
// Builds a delta for states that are > 64K in size.
void CaptureRewindStateLarge() { CaptureRewindStateDelta(false); }
// Builds a delta for states that are <= 64K in size.
void CaptureRewindState64K() { CaptureRewindStateDelta(true); }
void CaptureRewindStateNonDelta()
{
Console.WriteLine(RewindBuf.Size);
byte[] CurrentState = Global.Emulator.SaveStateBinary();
long offset = RewindBuf.Enqueue(0, CurrentState.Length + 1);
Stream stream = RewindBuf.Stream;
stream.Position = offset;
//write the header for a non-delta frame
stream.WriteByte(1); //i.e. true
stream.Write(CurrentState, 0, CurrentState.Length);
}
byte[] TempBuf = new byte[0];
void CaptureRewindStateDelta(bool isSmall)
{
byte[] CurrentState = Global.Emulator.SaveStateBinary();
//in case the state sizes mismatch, capture a full state rather than trying to do anything clever
if (CurrentState.Length != LastState.Length)
{
CaptureRewindStateNonDelta();
return;
}
int beginChangeSequence = -1;
bool inChangeSequence = false;
MemoryStream ms;
@ -309,46 +336,38 @@ namespace BizHawk.MultiClient
try
{
var writer = new BinaryWriter(ms);
if (CurrentState.Length != LastState.Length)
writer.Write(false); // delta state
for (int i = 0; i < CurrentState.Length; i++)
{
writer.Write(true); // full state
writer.Write(LastState);
}
else
{
writer.Write(false); // delta state
for (int i = 0; i < CurrentState.Length; i++)
if (inChangeSequence == false)
{
if (inChangeSequence == false)
{
if (i >= LastState.Length)
continue;
if (CurrentState[i] == LastState[i])
continue;
inChangeSequence = true;
beginChangeSequence = i;
if (i >= LastState.Length)
continue;
}
if (i - beginChangeSequence == 254 || i == CurrentState.Length - 1)
{
writer.Write((byte)(i - beginChangeSequence + 1));
if (isSmall) writer.Write((ushort)beginChangeSequence);
else writer.Write(beginChangeSequence);
writer.Write(LastState, beginChangeSequence, i - beginChangeSequence + 1);
inChangeSequence = false;
continue;
}
if (CurrentState[i] == LastState[i])
{
writer.Write((byte)(i - beginChangeSequence));
if (isSmall) writer.Write((ushort)beginChangeSequence);
else writer.Write(beginChangeSequence);
writer.Write(LastState, beginChangeSequence, i - beginChangeSequence);
inChangeSequence = false;
}
continue;
inChangeSequence = true;
beginChangeSequence = i;
continue;
}
if (i - beginChangeSequence == 254 || i == CurrentState.Length - 1)
{
writer.Write((byte)(i - beginChangeSequence + 1));
if (isSmall) writer.Write((ushort)beginChangeSequence);
else writer.Write(beginChangeSequence);
writer.Write(LastState, beginChangeSequence, i - beginChangeSequence + 1);
inChangeSequence = false;
continue;
}
if (CurrentState[i] == LastState[i])
{
writer.Write((byte)(i - beginChangeSequence));
if (isSmall) writer.Write((ushort)beginChangeSequence);
else writer.Write(beginChangeSequence);
writer.Write(LastState, beginChangeSequence, i - beginChangeSequence);
inChangeSequence = false;
}
}
}