public void CursorIsCorrectWithEmptyLastBlock()
{
var last = new BufferSegment();
last.SetMemory(new OwnedArray <byte>(new byte[4]), 0, 4);
var first = new BufferSegment();
first.SetMemory(new OwnedArray <byte>(new byte[2] {
1, 2
}), 0, 2);
first.SetNext(last);
var start = new ReadCursor(first);
var end = new ReadCursor(last);
var reader = new ReadableBufferReader(start, end);
reader.Take();
reader.Take();
reader.Take();
Assert.Same(last, reader.Cursor.Segment);
Assert.Equal(0, reader.Cursor.Index);
Assert.True(reader.End);
}
private void AdvanceTo(BufferSegment consumedSegment, int consumedIndex, BufferSegment examinedSegment, int examinedIndex)
{
if (consumedSegment == null)
{
return;
}
var returnStart = _readHead;
var returnEnd = consumedSegment;
var consumedBytes = new ReadOnlySequence <byte>(returnStart, _readIndex, consumedSegment, consumedIndex).Length;
_bufferedBytes -= consumedBytes;
Debug.Assert(_bufferedBytes >= 0);
_examinedEverything = false;
if (examinedSegment == _readTail)
{
// If we examined everything, we force ReadAsync to actually read from the underlying stream
// instead of returning a ReadResult from TryRead.
_examinedEverything = examinedIndex == _readTail.End - _readTail.Start;
}
// Three cases here:
// 1. All data is consumed. If so, we reset _readHead and _readTail to _readTail's original memory owner
// SetMemory on a IMemoryOwner will reset the internal Memory<byte> to be an empty segment
// 2. A segment is entirely consumed but there is still more data in nextSegments
// We are allowed to remove an extra segment. by setting returnEnd to be the next block.
// 3. We are in the middle of a segment.
// Move _readHead and _readIndex to consumedSegment and index
if (_bufferedBytes == 0)
{
_readTail.SetMemory(_readTail.MemoryOwner);
_readHead = _readTail;
returnEnd = _readTail;
_readIndex = 0;
}
else if (consumedIndex == returnEnd.Length)
{
var nextBlock = returnEnd.NextSegment;
_readHead = nextBlock;
_readIndex = 0;
returnEnd = nextBlock;
}
else
{
_readHead = consumedSegment;
_readIndex = consumedIndex;
}
// Remove all blocks that are freed (except the last one)
while (returnStart != returnEnd)
{
returnStart.ResetMemory();
returnStart = returnStart.NextSegment;
}
}
private void AllocateReadTail()
{
if (_readHead == null)
{
Debug.Assert(_readTail == null);
_readHead = CreateBufferSegment();
_readHead.SetMemory(_pool.Rent(GetSegmentSize()));
_readTail = _readHead;
}
else if (_readTail.WritableBytes < _minimumReadThreshold)
{
CreateNewTailSegment();
}
}
public void MovePrefersNextSegment()
{
var bufferSegment1 = new BufferSegment();
bufferSegment1.SetMemory(new OwnedArray <byte>(new byte[100]), 49, 99);
var bufferSegment2 = new BufferSegment();
bufferSegment2.SetMemory(new OwnedArray <byte>(new byte[100]), 0, 0);
bufferSegment1.SetNext(bufferSegment2);
var readableBuffer = new ReadOnlyBuffer <byte>(bufferSegment1, 0, bufferSegment2, 0);
var c1 = readableBuffer.GetPosition(readableBuffer.Start, 50);
Assert.Equal(0, c1.Index);
Assert.Equal(bufferSegment2, c1.Segment);
}
public void GetPositionPrefersNextSegment()
{
var bufferSegment1 = new BufferSegment();
bufferSegment1.SetMemory(new OwnedArray <byte>(new byte[100]), 49, 99);
var bufferSegment2 = new BufferSegment();
bufferSegment2.SetMemory(new OwnedArray <byte>(new byte[100]), 0, 0);
bufferSegment1.SetNext(bufferSegment2);
var readableBuffer = new ReadOnlySequence <byte>(bufferSegment1, 0, bufferSegment2, 0);
var c1 = readableBuffer.GetPosition(50);
Assert.Equal(0, c1.GetInteger());
Assert.Equal(bufferSegment2, c1.GetObject());
}
public void CursorIsCorrectWithEmptyLastBlock()
{
var last = new BufferSegment();
last.SetMemory(new OwnedArray <byte>(new byte[4]), 0, 4);
var first = new BufferSegment();
first.SetMemory(new OwnedArray <byte>(new byte[] { 1, 2 }), 0, 2);
first.SetNext(last);
var reader = BufferReader.Create(new ReadOnlyBuffer <byte>(first, first.Start, last, last.Start));
reader.Take();
reader.Take();
reader.Take();
Assert.Same(last, reader.Position.Segment);
Assert.Equal(0, reader.Position.Index);
Assert.True(reader.End);
}
public void CursorIsCorrectWithEmptyLastBlock()
{
var last = new BufferSegment();
last.SetMemory(new OwnedArray <byte>(new byte[4]), 0, 4);
var first = new BufferSegment();
first.SetMemory(new OwnedArray <byte>(new byte[] { 1, 2 }), 0, 2);
first.SetNext(last);
var reader = new BufferReader(new ReadOnlySequence <byte>(first, first.Start, last, last.Start));
reader.Read();
reader.Read();
reader.Read();
Assert.Same(last, reader.Position.GetObject());
Assert.Equal(0, reader.Position.GetInteger());
Assert.True(reader.End);
}
public void SegmentStartIsConsideredInBoundsCheck()
{
// 0 50 100 0 50 100
// [ ##############] -> [############## ]
// ^c1 ^c2
var bufferSegment1 = new BufferSegment();
bufferSegment1.SetMemory(new OwnedArray <byte>(new byte[100]), 50, 99);
var bufferSegment2 = new BufferSegment();
bufferSegment2.SetMemory(new OwnedArray <byte>(new byte[100]), 0, 50);
bufferSegment1.SetNext(bufferSegment2);
var readableBuffer = new ReadOnlyBuffer <byte>(bufferSegment1, 0, bufferSegment2, 50);
var c1 = readableBuffer.GetPosition(readableBuffer.Start, 25); // segment 1 index 75
var c2 = readableBuffer.GetPosition(readableBuffer.Start, 55); // segment 2 index 5
var sliced = readableBuffer.Slice(c1, c2);
Assert.Equal(30, sliced.Length);
}
public void GetPositionDoesNotCrossOutsideBuffer()
{
var bufferSegment1 = new BufferSegment();
bufferSegment1.SetMemory(new OwnedArray <byte>(new byte[100]), 0, 100);
var bufferSegment2 = new BufferSegment();
bufferSegment2.SetMemory(new OwnedArray <byte>(new byte[100]), 0, 100);
var bufferSegment3 = new BufferSegment();
bufferSegment3.SetMemory(new OwnedArray <byte>(new byte[100]), 0, 0);
bufferSegment1.SetNext(bufferSegment2);
bufferSegment2.SetNext(bufferSegment3);
var readableBuffer = new ReadOnlySequence <byte>(bufferSegment1, 0, bufferSegment2, 100);
var c1 = readableBuffer.GetPosition(200);
Assert.Equal(100, c1.GetInteger());
Assert.Equal(bufferSegment2, c1.GetObject());
}
public void GetPositionDoesNotCrossOutsideBuffer()
{
var bufferSegment1 = new BufferSegment();
bufferSegment1.SetMemory(new OwnedArray <byte>(new byte[100]), 0, 100);
var bufferSegment2 = new BufferSegment();
bufferSegment2.SetMemory(new OwnedArray <byte>(new byte[100]), 0, 100);
var bufferSegment3 = new BufferSegment();
bufferSegment3.SetMemory(new OwnedArray <byte>(new byte[100]), 0, 0);
bufferSegment1.SetNext(bufferSegment2);
bufferSegment2.SetNext(bufferSegment3);
var readableBuffer = new ReadOnlyBuffer <byte>(bufferSegment1, 0, bufferSegment2, 100);
var c1 = readableBuffer.GetPosition(readableBuffer.Start, 200);
Assert.Equal(100, c1.Index);
Assert.Equal(bufferSegment2, c1.Segment);
}
