#pragma warning restore 0414
public Asn1Reader(
ReadOnlySpan <byte> buffer,
int maxDepth = 8)
{
if (maxDepth < 0 || maxDepth > 8)
{
throw new IndexOutOfRangeException();
}
_buffer = buffer;
_maxDepth = 1 + maxDepth;
_depth = 0;
_failed = false;
_stack0 = new StartAndLength(0, buffer.Length);
_stack1 = default(StartAndLength);
_stack2 = default(StartAndLength);
_stack3 = default(StartAndLength);
_stack4 = default(StartAndLength);
_stack5 = default(StartAndLength);
_stack6 = default(StartAndLength);
_stack7 = default(StartAndLength);
_stack8 = default(StartAndLength);
}
public void Null()
{
StartAndLength bytes = Read(0x05);
if (_failed || !bytes.IsEmpty)
{
Fail();
}
}
public void Null()
{
StartAndLength bytes = Read(0x05);
if (_failed || bytes.Length != 0)
{
Fail();
}
}
public void BeginSequence()
{
StartAndLength bytes = Read(0x30);
if (!_failed)
{
_depth++;
Top = bytes;
}
}
public Asn1Reader(
ref ReadOnlySpan <byte> buffer,
int maxDepth = 8)
{
#if UNSAFE
_buffer = Unsafe.AsPointer(ref buffer);
#else
_buffer = buffer;
#endif
_depth = 0;
_failed = false;
_stack = new StartAndLength[maxDepth];
Top = new StartAndLength(0, buffer.Length);
}
private StartAndLength Read(
int tag)
{
StartAndLength top = Top;
StartAndLength result = default(StartAndLength);
ReadOnlySpan <byte> span = top.ApplyTo(_buffer);
int length = 0;
if (_failed || span.Length < 2 || span[0] != tag)
{
goto fail;
}
int pos = 2;
if ((span[1] & 0x80) == 0)
{
length = span[1];
}
else
{
int c = span[1] & 0x7F;
if (c == 0 || c > sizeof(int) || c > span.Length - 2 || span[2] == 0)
{
goto fail;
}
while (c-- > 0)
{
length = (length << 8) | span[pos++];
}
if (length < 0x80)
{
goto fail;
}
}
if (length > span.Length - pos)
{
goto fail;
}
result = top.Slice(pos, length);
Top = top.Slice(pos + length);
goto done;
fail:
Fail();
done:
return(result);
}
public static StartAndLength[] CalculateStartAndLengthForAllRanks(int totalLayers, Mpi mpi)
{
int size = mpi.Size;
var result = new StartAndLength[size];
for (int rank = 0; rank < result.Length; rank++)
{
int start = DetermineStart(totalLayers, size, rank);
int length = DetermineLength(totalLayers, size, rank);
result[rank] = new StartAndLength(start, length);
}
return(result);
}
private StartAndLength Read(
int tag)
{
StartAndLength top = Unsafe.Add(ref _stack0, _depth);
ReadOnlySpan <byte> span = top.ApplyTo(_buffer);
if (_failed || span.Length < 2 || span[0] != tag)
{
goto fail;
}
int start = 2;
int length = 0;
if ((span[1] & ~0x7F) == 0)
{
length = span[1];
}
else
{
int count = span[1] & 0x7F;
if (count < 1 || count > sizeof(int) || count > span.Length - 2 || span[2] == 0)
{
goto fail;
}
while (count-- > 0)
{
length = (length << 8) | span[start++];
}
if (length < 0x80)
{
goto fail;
}
}
if (length > span.Length - start)
{
goto fail;
}
Unsafe.Add(ref _stack0, _depth) = top.Slice(start + length);
return(top.Slice(start, length));
fail:
Fail();
return(default(StartAndLength));
}
public void BeginSequence()
{
StartAndLength bytes = Read(0x30);
if (_failed)
{
Fail();
}
else
{
_depth++;
if (_depth == _maxDepth)
{
throw new IndexOutOfRangeException();
}
Unsafe.Add(ref _stack0, _depth) = bytes;
}
}
private void Fail()
{
_failed = true;
_depth = 0;
_stack0 = default(StartAndLength);
}
