private static bool TryGetBufferedLengthPrefixedString(
Utf8Memory stringToken,
out Utf8Memory value)
{
ReadOnlySpan <byte> stringTokenSpan = stringToken.Memory.Span;
byte typeMarker = stringTokenSpan[0];
stringTokenSpan = stringTokenSpan.Slice(start: 1);
int start;
long length;
if (JsonBinaryEncoding.TypeMarker.IsEncodedLengthString(typeMarker))
{
start = JsonBinaryEncoding.TypeMarkerLength;
length = JsonBinaryEncoding.GetStringLengths(typeMarker);
}
else
{
switch (typeMarker)
{
case JsonBinaryEncoding.TypeMarker.String1ByteLength:
if (stringTokenSpan.Length < JsonBinaryEncoding.OneByteLength)
{
value = default;
return(false);
}
start = JsonBinaryEncoding.TypeMarkerLength + JsonBinaryEncoding.OneByteLength;
length = stringTokenSpan[0];
break;
case JsonBinaryEncoding.TypeMarker.String2ByteLength:
if (stringTokenSpan.Length < JsonBinaryEncoding.TwoByteLength)
{
value = default;
return(false);
}
start = JsonBinaryEncoding.TypeMarkerLength + JsonBinaryEncoding.TwoByteLength;
length = MemoryMarshal.Read <ushort>(stringTokenSpan);
break;
case JsonBinaryEncoding.TypeMarker.String4ByteLength:
if (stringTokenSpan.Length < JsonBinaryEncoding.FourByteLength)
{
value = default;
return(false);
}
start = JsonBinaryEncoding.TypeMarkerLength + JsonBinaryEncoding.FourByteLength;
length = MemoryMarshal.Read <uint>(stringTokenSpan);
break;
default:
value = default;
return(false);
}
if ((start + length) > stringToken.Length)
{
value = default;
return(false);
}
}
value = stringToken.Slice(start: start, length: (int)length);
return(true);
}