// Copyright (c) 2006  Dustin Sallings <dustin@spy.net>package net.spy.memcached.transcoders;/** * Utility class for transcoding Java types. */public final class TranscoderUtils {	private final boolean packZeros;	/**	 * Get an instance of TranscoderUtils.	 *	 * @param pack if true, remove all zero bytes from the MSB of the packed num	 */	public TranscoderUtils(boolean pack) {		super();		packZeros=pack;	}	public byte[] encodeNum(long l, int maxBytes) {		byte[] rv=new byte[maxBytes];		for(int i=0; i<rv.length; i++) {			int pos=rv.length-i-1;			rv[pos]=(byte) ((l >> (8 * i)) & 0xff);		}		if(packZeros) {			int firstNon0=0;			for(;firstNon0<rv.length && rv[firstNon0]==0; firstNon0++) {				// Just looking for what we can reduce			}			if(firstNon0 > 0) {				byte[] tmp=new byte[rv.length - firstNon0];				System.arraycopy(rv, firstNon0, tmp, 0, rv.length-firstNon0);				rv=tmp;			}		}		return rv;	}	public byte[] encodeLong(long l) {		return encodeNum(l, 8);	}	public long decodeLong(byte[] b) {		long rv=0;		for(byte i : b) {			rv = (rv << 8) | (i<0?256+i:i);		}		return rv;	}	public byte[] encodeInt(int in) {		return encodeNum(in, 4);	}	public int decodeInt(byte[] in) {		assert in.length <= 4			: "Too long to be an int (" + in.length + ") bytes";		return (int)decodeLong(in);	}	public byte[] encodeByte(byte in) {		return new byte[]{in};	}	public byte decodeByte(byte[] in) {		assert in.length <= 1 : "Too long for a byte";		byte rv=0;		if(in.length == 1) {			rv=in[0];		}		return rv;	}	public byte[] encodeBoolean(boolean b) {		byte[] rv=new byte[1];		rv[0]=(byte)(b?'1':'0');		return rv;	}	public boolean decodeBoolean(byte[] in) {		assert in.length == 1 : "Wrong length for a boolean";		return in[0] == '1';	}}