private void SeekBackward(int offset)
{
IntPtr memSegPtr = _memSegPtr;
int writeIndex = _writeIndex;
int nextWrited = _nextWrited;
int readIndex = _readIndex - offset;
while (readIndex < -1)
{
nextWrited += MemorySegment.GetUsed(memSegPtr);
memSegPtr = MemorySegment.GetPrev(memSegPtr);
if (memSegPtr == IntPtr.Zero)
{
throw new UnexpectedEndOfBufferException();
}
writeIndex = MemorySegment.GetUsed(memSegPtr) - 1;
readIndex += writeIndex;
}
_memSegPtr = memSegPtr;
_memSegSize = MemorySegment.GetSize(_memSegPtr);
unsafe
{
_dataPtr = (byte *)(void *)MemorySegment.GetDataPtr(_memSegPtr);
}
_writeIndex = writeIndex;
_nextWrited = nextWrited;
_readIndex = readIndex;
}
private void SeekForward(int offset)
{
IntPtr memSegPtr = _memSegPtr;
int writeIndex = _writeIndex;
int nextWrited = _nextWrited;
int readIndex = _readIndex + offset;
while (readIndex > writeIndex)
{
memSegPtr = MemorySegment.GetNext(memSegPtr);
if (memSegPtr == IntPtr.Zero)
{
throw new UnexpectedEndOfBufferException();
}
int used = MemorySegment.GetUsed(memSegPtr);
readIndex -= writeIndex + 1;
writeIndex = used - 1;
nextWrited -= used;
}
_memSegPtr = memSegPtr;
_memSegSize = MemorySegment.GetSize(_memSegPtr);
unsafe
{
_dataPtr = (byte *)(void *)MemorySegment.GetDataPtr(_memSegPtr);
}
_writeIndex = writeIndex;
_nextWrited = nextWrited;
_readIndex = readIndex;
}
public void Attach(IntPtr memSegPtr)
{
_memSegPtr = memSegPtr;
_memSegSize = MemorySegment.GetSize(_memSegPtr);
unsafe
{
_dataPtr = (byte *)(void *)MemorySegment.GetDataPtr(_memSegPtr);
}
_lastMemSegPtr = memSegPtr;
_writeIndex = MemorySegment.GetUsed(memSegPtr) - 1;
_nextWrited = 0;
_readIndex = -1;
_released = false;
}
public void TestHeader()
{
IntPtr ptrFirst = IntPtr.Zero;
IntPtr ptrSecond = IntPtr.Zero;
try
{
Assert.True(IntPtr.Size == 8);
ptrFirst = Alloc(10);
ptrSecond = Alloc(10);
MemorySegment.SetNext(ptrFirst, IntPtr.Zero);
MemorySegment.SetPrev(ptrSecond, IntPtr.Zero);
MemorySegment.SetSize(ptrFirst, 0);
MemorySegment.SetSize(ptrSecond, 0);
MemorySegment.SetUsed(ptrFirst, 0);
MemorySegment.SetUsed(ptrSecond, 0);
Assert.True(MemorySegment.GetNext(ptrFirst) == IntPtr.Zero);
Assert.True(MemorySegment.GetPrev(ptrSecond) == IntPtr.Zero);
Assert.True(MemorySegment.GetSize(ptrFirst) == 0);
Assert.True(MemorySegment.GetSize(ptrSecond) == 0);
Assert.True(MemorySegment.GetUsed(ptrFirst) == 0);
Assert.True(MemorySegment.GetUsed(ptrSecond) == 0);
MemorySegment.SetNext(ptrFirst, ptrSecond);
MemorySegment.SetPrev(ptrSecond, ptrFirst);
MemorySegment.SetSize(ptrFirst, 10);
MemorySegment.SetSize(ptrSecond, 9);
MemorySegment.SetUsed(ptrFirst, 8);
MemorySegment.SetUsed(ptrSecond, 4);
Assert.True(MemorySegment.GetNext(ptrFirst) == ptrSecond);
Assert.True(MemorySegment.GetPrev(ptrSecond) == ptrFirst);
Assert.True(MemorySegment.GetSize(ptrFirst) == 10);
Assert.True(MemorySegment.GetSize(ptrSecond) == 9);
Assert.True(MemorySegment.GetUsed(ptrFirst) == 8);
Assert.True(MemorySegment.GetUsed(ptrSecond) == 4);
Assert.True(
MemorySegment.GetUsed(ptrFirst) ==
MemorySegment.GetUsed(
MemorySegment.GetMemSegPtrByDataPtr(
MemorySegment.GetDataPtr(ptrFirst)
)
)
);
}
finally
{
Release(ptrFirst);
Release(ptrSecond);
}
}