com.linkedin.pinot.common.utils.primitive.ByteArray.java Source code

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Here is the source code for com.linkedin.pinot.common.utils.primitive.ByteArray.java

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/**
 * Copyright (C) 2014-2016 LinkedIn Corp. (pinot-core@linkedin.com)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.linkedin.pinot.common.utils.primitive;

import java.util.Arrays;
import javax.annotation.Nonnull;
import org.apache.commons.codec.binary.Hex;

/**
 * Wrapper around byte[] that provides additional features such as:
 * <ul>
 *   <li> Implements comparable interface, so comparison and sorting can be performed. </li>
 *   <li> Implements equals() and hashCode(), so it can be used as key for HashMap/Set. </li>
 * </ul>
 */
public class ByteArray implements Comparable<ByteArray> {
    private final byte[] _bytes;

    public ByteArray(byte[] bytes) {
        _bytes = bytes;
    }

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

    public int length() {
        return _bytes.length;
    }

    /**
     * Static utility function to convert a byte[] to Hex string.
     *
     * @param bytes byte[] to convert
     * @return Equivalent Hex String.
     */
    public static String toHexString(byte[] bytes) {
        return Hex.encodeHexString(bytes);
    }

    @Override
    public String toString() {
        return toHexString(_bytes);
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        ByteArray bytes = (ByteArray) o;

        return Arrays.equals(_bytes, bytes._bytes);
    }

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

    @Override
    public int compareTo(@Nonnull ByteArray that) {
        if (this == that) {
            return 0;
        }

        return compare(_bytes, that._bytes);
    }

    /**
     * Compares two byte[] values. The comparison performed is on unsigned value for each byte.
     * Returns:
     * <ul>
     *   <li> 0 if both values are identical. </li>
     *   <li> -ve integer if first value is smaller than the second. </li>
     *   <li> +ve integer if first value is larger than the second. </li>
     * </ul>
     *
     * @param bytes1 First byte[] to compare.
     * @param bytes2 Second byte[] to compare.
     * @return Result of comparison as stated above.
     */
    public static int compare(byte[] bytes1, byte[] bytes2) {
        int len1 = bytes1.length;
        int len2 = bytes2.length;
        int lim = Math.min(len1, len2);

        for (int k = 0; k < lim; k++) {
            // Java byte is always signed, but we need to perform unsigned comparison.
            int ai = Byte.toUnsignedInt(bytes1[k]);
            int bi = Byte.toUnsignedInt(bytes2[k]);
            if (ai != bi) {
                return ai - bi;
            }
        }
        return len1 - len2;
    }
}