// same as DataOutput.writeVLong but accepts negative values
internal static void WriteVLong(DataOutput @out, long i)
{
int k = 0;
while ((i & ~0x7FL) != 0L && k++ < 8)
{
@out.WriteByte(unchecked((byte)(sbyte)((i & 0x7FL) | 0x80L)));
i = (long)((ulong)i >> 7);
}
@out.WriteByte((byte)(sbyte)i);
}
private static void EncodeLiterals(byte[] bytes, int token, int anchor, int literalLen, DataOutput @out)
{
@out.WriteByte((byte)(sbyte)token);
// encode literal length
if (literalLen >= 0x0F)
{
EncodeLen(literalLen - 0x0F, @out);
}
// encode literals
@out.WriteBytes(bytes, anchor, literalLen);
}
private static void EncodeSequence(byte[] bytes, int anchor, int matchRef, int matchOff, int matchLen, DataOutput @out)
{
int literalLen = matchOff - anchor;
Debug.Assert(matchLen >= 4);
// encode token
int token = (Math.Min(literalLen, 0x0F) << 4) | Math.Min(matchLen - 4, 0x0F);
EncodeLiterals(bytes, token, anchor, literalLen, @out);
// encode match dec
int matchDec = matchOff - matchRef;
Debug.Assert(matchDec > 0 && matchDec < 1 << 16);
@out.WriteByte((byte)(sbyte)matchDec);
@out.WriteByte((byte)(sbyte)((int)((uint)matchDec >> 8)));
// encode match len
if (matchLen >= MIN_MATCH + 0x0F)
{
EncodeLen(matchLen - 0x0F - MIN_MATCH, @out);
}
}
private static void EncodeLen(int l, DataOutput @out)
{
while (l >= 0xFF)
{
@out.WriteByte(unchecked((byte)(sbyte)0xFF));
l -= 0xFF;
}
@out.WriteByte((byte)(sbyte)l);
}