internal static bool TryGetBuffer(Position begin, Position end, out ReadOnlyMemory <T> data, out Position next)
{
var segment = begin.Segment;
switch (segment)
{
case null:
data = default;
next = default;
return(false);
case IMemoryList <T> bufferSegment:
var startIndex = begin.Index;
var endIndex = bufferSegment.Memory.Length;
if (segment == end.Segment)
{
endIndex = end.Index;
next = default;
}
else
{
var nextSegment = bufferSegment.Next;
if (nextSegment == null)
{
if (end.Segment != null)
{
ThrowHelper.ThrowInvalidOperationException(ExceptionResource.EndCursorNotReached);
}
next = default;
}
else
{
next = new Position(nextSegment, 0);
}
}
data = bufferSegment.Memory.Slice(startIndex, endIndex - startIndex);
return(true);
case OwnedMemory <T> ownedMemory:
data = ownedMemory.Memory.Slice(begin.Index, end.Index - begin.Index);
if (segment != end.Segment)
{
ThrowHelper.ThrowInvalidOperationException(ExceptionResource.EndCursorNotReached);
}
next = default;
return(true);
case T[] array:
data = new Memory <T>(array, begin.Index, end.Index - begin.Index);
if (segment != end.Segment)
{
ThrowHelper.ThrowInvalidOperationException(ExceptionResource.EndCursorNotReached);
}
next = default;
return(true);
}
ThrowHelper.ThrowNotSupportedException();
next = default;
return(false);
}
internal bool TryGetBuffer(SequencePosition start, SequencePosition end, out ReadOnlyMemory <T> data, out SequencePosition next)
{
if (start.Segment == null)
{
data = default;
next = default;
return(false);
}
var startIndex = start.Index;
var endIndex = end.Index;
var type = GetBufferType();
startIndex = GetIndex(startIndex);
endIndex = GetIndex(endIndex);
switch (type)
{
case BufferType.MemoryList:
var bufferSegment = (IMemoryList <T>)start.Segment;
var currentEndIndex = bufferSegment.Memory.Length;
if (bufferSegment == end.Segment)
{
currentEndIndex = endIndex;
next = default;
}
else
{
var nextSegment = bufferSegment.Next;
if (nextSegment == null)
{
if (end.Segment != null)
{
ThrowHelper.ThrowInvalidOperationException(ExceptionResource.EndCursorNotReached);
}
next = default;
}
else
{
next = new SequencePosition(nextSegment, 0);
}
}
data = bufferSegment.Memory.Slice(startIndex, currentEndIndex - startIndex);
return(true);
case BufferType.OwnedMemory:
var ownedMemory = (OwnedMemory <T>)start.Segment;
data = ownedMemory.Memory.Slice(startIndex, endIndex - startIndex);
if (ownedMemory != end.Segment)
{
ThrowHelper.ThrowInvalidOperationException(ExceptionResource.EndCursorNotReached);
}
next = default;
return(true);
case BufferType.Array:
var array = (T[])start.Segment;
data = new Memory <T>(array, startIndex, endIndex - startIndex);
if (array != end.Segment)
{
ThrowHelper.ThrowInvalidOperationException(ExceptionResource.EndCursorNotReached);
}
next = default;
return(true);
}
ThrowHelper.ThrowNotSupportedException();
next = default;
return(false);
}
