piuk.blockchain.android.Hash.java Source code

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Here is the source code for piuk.blockchain.android.Hash.java

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/*
 * Copyright 2011-2012 the original author or authors.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package piuk.blockchain.android;

import java.io.Serializable;
import java.util.Arrays;

import org.apache.commons.lang.ArrayUtils;

import org.spongycastle.util.encoders.Hex;

public class Hash implements Serializable {
    private static final long serialVersionUID = 1L;
    private final byte[] hash;

    public Hash() {
        this.hash = null;
    }

    public Hash(String hex) {
        this.hash = Hex.decode(hex);
    }

    public Hash(byte[] bytes) {
        this.hash = bytes;
    }

    public void reverse() {
        ArrayUtils.reverse(hash);
    }

    public byte[] getBytes() {
        return hash;
    }

    public int nLeadingZeros() {
        int n = 0;

        for (byte b : hash) {
            if (b == 0)
                n += 8;
            else {
                n += Math.max(0, Integer.numberOfLeadingZeros(b) - (3 * 8));
                break;
            }
        }

        return n;
    }

    public boolean isNull() {
        if (hash == null || hash.length == 0)
            return true;

        for (byte b : hash) {
            if (b != 0)
                return false;
        }

        return true;
    }

    @Override
    public String toString() {

        if (hash == null)
            return null;

        return new String(Hex.encode(hash));
    }

    @Override
    public int hashCode() {
        return Arrays.hashCode(hash);
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        Hash other = (Hash) obj;
        if (!Arrays.equals(hash, other.hash))
            return false;
        return true;
    }
}