net.spy.memcached.transcoders.TranscoderUtils Maven / Gradle / Ivy
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// Copyright (c) 2006 Dustin Sallings
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';
}
}