private static TimeSpan?TryReadDurationFast(ProtoReader source, ref ProtoReader.State state)
{
int offset = state.OffsetInCurrent;
var span = state.Span;
int prefixLength = ProtoReader.State.ParseVarintUInt32(span, offset, out var len);
offset += prefixLength;
if (len == 0)
{
return(TimeSpan.Zero);
}
if ((prefixLength + len) > state.RemainingInCurrent)
{
return(null); // don't have entire submessage
}
if (span[offset] != (1 << 3))
{
return(null); // expected field 1
}
var msgOffset = 1 + ProtoReader.State.TryParseUInt64Varint(span, 1 + offset, out var seconds);
ulong nanos = 0;
if (msgOffset < len)
{
if (span[msgOffset++ + offset] != (2 << 3))
{
return(null); // expected field 2
}
msgOffset += ProtoReader.State.TryParseUInt64Varint(span, msgOffset + offset, out nanos);
}
if (msgOffset != len)
{
return(null); // expected no more fields
}
state.Skip(prefixLength + (int)len);
source.Advance(prefixLength + len);
return(FromDurationSeconds((long)seconds, (int)(long)nanos));
}
internal void Advance(long count) => _reader.Advance(count);
