private void Compare <T>(ISpanComparer comparer, int size) where T : struct, IComparable <T>
{
Random rng = new Random();
for (int i = 0; i < 100; ++i)
{
byte[] leftData = new byte[32];
byte[] rightData = new byte[32];
rng.NextBytes(leftData);
rng.NextBytes(rightData);
T a = MemoryMarshal.Cast <byte, T>(leftData.AsSpan())[0];
T b = MemoryMarshal.Cast <byte, T>(rightData.AsSpan())[0];
var leftSpan = leftData.AsSpan().Slice(0, size);
var rightSpan = rightData.AsSpan().Slice(0, size);
Assert.AreEqual(
a.CompareTo(b),
comparer.Compare(leftSpan, rightSpan));
Assert.AreEqual(
b.CompareTo(a),
comparer.Compare(rightSpan, leftSpan));
Assert.AreEqual(0, comparer.Compare(leftSpan, leftSpan));
Assert.AreEqual(0, comparer.Compare(rightSpan, rightSpan));
}
}
public static void SortVector(
Span <byte> buffer,
int vectorUOffset,
int vtableIndex,
int?keyInlineSize,
ISpanComparer comparer)
{
checked
{
int vectorStartOffset = vectorUOffset + (int)ScalarSpanReader.ReadUInt(buffer.Slice(vectorUOffset));
int vectorLength = (int)ScalarSpanReader.ReadUInt(buffer.Slice(vectorStartOffset));
int index0Position = vectorStartOffset + sizeof(int);
// Traverse the vector and figure out the offsets of all the keys.
// Store that in some local data, hopefully on the stack. 512 is somewhat arbitrary, but we want to avoid stack overflows.
Span <(int offset, int length, int tableOffset)> keyOffsets =
vectorLength < 512
? stackalloc (int, int, int)[vectorLength]