public void TestReadBytesCorruption()
{
using var zw = new ZwinderBuffer(new RewindConfig
{
BufferSize = 1,
TargetFrameLength = 1
});
zw.Capture(0, s =>
{
s.Write(new byte[] { 1, 2, 3, 4 });
});
zw.Capture(1, s =>
{
s.Write(new byte[] { 5, 6, 7, 8 });
});
var state = zw.GetState(0);
Assert.AreEqual(0, state.Frame);
Assert.AreEqual(4, state.Size);
var bb = new byte[2];
state.GetReadStream().Read(bb, 0, 2);
Assert.AreEqual(1, bb[0]);
Assert.AreEqual(2, bb[1]);
}
public void BufferStressTest()
{
var r = new Random(8675309);
using var zw = new ZwinderBuffer(new RewindConfig
{
BufferSize = 1,
TargetFrameLength = 1
});
var buff = new byte[40000];
for (int round = 0; round < 10; round++)
{
for (int i = 0; i < 500; i++)
{
zw.Capture(i, s =>
{
var length = r.Next(40000);
var bw = new BinaryWriter(s);
var bytes = buff.AsSpan(0, length);
r.NextBytes(bytes);
bw.Write(length);
bw.Write(bytes);
bw.Write(CRC32.Calculate(bytes));
});
}
for (int i = 0; i < zw.Count; i++)
{
var info = zw.GetState(i);
var s = info.GetReadStream();
var br = new BinaryReader(s);
var length = info.Size;
if (length != br.ReadInt32() + 8)
{
throw new Exception("Length field corrupted");
}
var bytes = buff.AsSpan(0, length - 8);
br.Read(bytes);
if (br.ReadUInt32() != CRC32.Calculate(bytes))
{
throw new Exception("Data or CRC field corrupted");
}
}
}
}
public void CountEvictWorks()
{
using var zb = new ZwinderBuffer(new RewindConfig
{
BufferSize = 1,
TargetFrameLength = 1
});
var ss = new StateSource
{
PaddingData = new byte[10]
};
var stateCount = 0;
for (int i = 0; i < 1000000; i++)
{
zb.Capture(i, s => ss.SaveStateBinary(new BinaryWriter(s)), j => stateCount--, true);
stateCount++;
}
Assert.AreEqual(zb.Count, stateCount);
}
public void SaveCreateBufferRoundTrip()
{
RewindConfig config = new RewindConfig
{
BufferSize = 1,
TargetFrameLength = 10
};
var buff = new ZwinderBuffer(config);
var ss = new StateSource {
PaddingData = new byte[500]
};
for (var frame = 0; frame < 2090; frame++)
{
ss.Frame = frame;
buff.Capture(frame, (s) => ss.SaveStateBinary(new BinaryWriter(s)));
}
// states are 504 bytes large, buffer is 1048576 bytes large
Assert.AreEqual(buff.Count, 2080);
Assert.AreEqual(buff.GetState(0).Frame, 10);
Assert.AreEqual(buff.GetState(2079).Frame, 2089);
Assert.AreEqual(StateSource.GetFrameNumberInState(buff.GetState(0).GetReadStream()), 10);
Assert.AreEqual(StateSource.GetFrameNumberInState(buff.GetState(2079).GetReadStream()), 2089);
var ms = new MemoryStream();
buff.SaveStateBinary(new BinaryWriter(ms));
ms.Position = 0;
var buff2 = ZwinderBuffer.Create(new BinaryReader(ms), config);
Assert.AreEqual(buff.Size, buff2.Size);
Assert.AreEqual(buff.Used, buff2.Used);
Assert.AreEqual(buff2.Count, 2080);
Assert.AreEqual(buff2.GetState(0).Frame, 10);
Assert.AreEqual(buff2.GetState(2079).Frame, 2089);
Assert.AreEqual(StateSource.GetFrameNumberInState(buff2.GetState(0).GetReadStream()), 10);
Assert.AreEqual(StateSource.GetFrameNumberInState(buff2.GetState(2079).GetReadStream()), 2089);
}
public void WhatIfTheHeadStateWrapsAround()
{
var ss = new StateSource
{
PaddingData = new byte[400 * 1000]
};
using var zw = new ZwinderBuffer(new RewindConfig
{
BufferSize = 1,
TargetFrameLength = 1
});
// Need to get data in the zwinderbuffer so that the last state, and the last state in particular, wraps around
ss.Frame = 1;
zw.Capture(1, s => ss.SaveStateBinary(new BinaryWriter(s)), null, true);
ss.Frame = 2;
zw.Capture(2, s => ss.SaveStateBinary(new BinaryWriter(s)), null, true);
ss.Frame = 3;
zw.Capture(3, s => ss.SaveStateBinary(new BinaryWriter(s)), null, true);
zw.SaveStateBinary(new BinaryWriter(new MemoryStream()));
}
public void TestWriteByteCorruption()
{
using var zw = new ZwinderBuffer(new RewindConfig
{
BufferSize = 1,
TargetFrameLength = 1
});
zw.Capture(0, s =>
{
s.WriteByte(1);
s.WriteByte(2);
s.WriteByte(3);
s.WriteByte(4);
});
zw.Capture(1, s =>
{
s.WriteByte(5);
s.WriteByte(6);
s.WriteByte(7);
s.WriteByte(8);
});
zw.GetState(0).GetReadStream(); // Rewinds the backing store
zw.Capture(2, s =>
{
s.WriteByte(9);
s.WriteByte(10);
s.WriteByte(11);
s.WriteByte(12);
});
var state = zw.GetState(0);
Assert.AreEqual(0, state.Frame);
Assert.AreEqual(4, state.Size);
Assert.AreEqual(1, state.GetReadStream().ReadByte());
}
