Class Compress

ZezeJava/ZezeJava/src/main/java/Zeze/Net/Compress.java:7–138

// RFC2118
public class Compress implements Codec {
	private final @NotNull Codec sink;
	private int pos;
	private int rem;
	private final byte[] dict = new byte[8192];
	private final short[] hash = new short[65536];
	private int idx;
	private int match_idx;
	private int match_off = -1;
	private int match_len;
	private boolean flushed = true;

	public Compress(@NotNull Codec sink) {
		this.sink = sink;
		Arrays.fill(hash, (short)-1);
	}

	protected int getPos() {
		return pos;
	}

	protected void putBits(int val, int nbits) throws CodecException {
		pos += nbits;
		rem |= val << (32 - pos);
		while (pos > 7) {
			sink.update((byte)(rem >> 24));
			pos -= 8;
			rem <<= 8;
		}
	}

	private void putLiteral(byte c) throws CodecException {
		if (c >= 0)
			putBits(c, 8); // 0xxx xxxx
		else
			putBits(c & 0x7f | 0x100, 9); // 1 0xxx xxxx
	}

	private void putTuple(int off, int len) throws CodecException {
		if (off < 64)
			putBits(0x3c0 | off, 10); // 11 11xx xxxx
		else if (off < 320)
			putBits(0xe00 | (off - 64), 12); // 1110 xxxx xxxx
		else
			putBits(0xc000 | (off - 320), 16); // 110x xxxx xxxx xxxx
		if (len < 4) // len == 3
			putBits(0, 1); // 0
		else if (len < 8)
			putBits(0x08 | (len & 0x03), 4); // 10xx
		else if (len < 16)
			putBits(0x30 | (len & 0x07), 6); // 11 0xxx
		else if (len < 32)
			putBits(0xe0 | (len & 0x0f), 8); // 1110 xxxx
		else if (len < 64)
			putBits(0x3c0 | (len & 0x1f), 10); // 11 110x xxxx
		else if (len < 128)
			putBits(0xf80 | (len & 0x3f), 12); // 1111 10xx xxxx
		else if (len < 256)