private static int EncodeString(string value, Span <byte> headerBlock, bool huffmanEncode)
{
byte[] data = Encoding.ASCII.GetBytes(value);
byte prefix;
if (!huffmanEncode)
{
prefix = 0;
}
else
{
int len = HuffmanEncoder.GetEncodedLength(data);
byte[] huffmanData = new byte[len];
HuffmanEncoder.Encode(data, huffmanData);
data = huffmanData;
prefix = 0x80;
}
int bytesGenerated = 0;
bytesGenerated += EncodeInteger(data.Length, prefix, 0x80, headerBlock);
data.AsSpan().CopyTo(headerBlock.Slice(bytesGenerated));
bytesGenerated += data.Length;
return(bytesGenerated);
}
public static int EncodeHeader(Span <byte> buffer, string name, string value, QPackFlags flags = QPackFlags.None)
{
byte[] data = Encoding.ASCII.GetBytes(name);
byte prefix;
if (!flags.HasFlag(QPackFlags.HuffmanEncodeName))
{
prefix = 0b0010_0000;
}
else
{
int len = HuffmanEncoder.GetEncodedLength(data);
byte[] huffmanData = new byte[len];
HuffmanEncoder.Encode(data, huffmanData);
data = huffmanData;
prefix = 0b0010_1000;
}
if (flags.HasFlag(QPackFlags.NeverIndexed))
{
prefix |= 0b0001_0000;
}
int bytesGenerated = 0;
// write name string header.
bytesGenerated += EncodeInteger(buffer, data.Length, prefix, 0b1111_1000);
// write name string.
data.AsSpan().CopyTo(buffer.Slice(bytesGenerated));
bytesGenerated += data.Length;
// write value string.
bytesGenerated += EncodeString(buffer.Slice(bytesGenerated), value, flags.HasFlag(QPackFlags.HuffmanEncodeValue));
return(bytesGenerated);
}