com.liveramp.cascading_ext.Bytes.java Source code

Introduction

Here is the source code for com.liveramp.cascading_ext.Bytes.java

Source

/**
 *  Copyright 2012 LiveRamp
 *
 *  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.liveramp.cascading_ext;

import cascading.tuple.Tuple;
import cascading.tuple.TupleEntry;
import com.google.common.primitives.UnsignedBytes;
import org.apache.commons.codec.binary.Hex;
import org.apache.hadoop.io.BytesWritable;

import java.nio.ByteBuffer;
import java.util.Comparator;

/**
 * Collection of methods for safely converting between byte[], BytesWritable and ByteBuffer. Some
 * byte[] methods delegate to Guava's UnsignedBytes
 */
public class Bytes {
    private static final Comparator<byte[]> BYTES_COMPARATOR = UnsignedBytes.lexicographicalComparator();

    /**
     * If the given ByteBuffer wraps completely its underlying byte array, return the underlying
     * byte array (no copy). Otherwise, return a deep copy of the range represented by the given
     * ByteBuffer.
     *
     * @param byteBuffer
     */
    public static byte[] byteBufferToByteArray(ByteBuffer byteBuffer) {
        if (wrapsFullArray(byteBuffer)) {
            return byteBuffer.array();
        }
        byte[] target = new byte[byteBuffer.remaining()];
        byteBufferToByteArray(byteBuffer, target, 0);
        return target;
    }

    public static int byteBufferToByteArray(ByteBuffer byteBuffer, byte[] target, int offset) {
        int remaining = byteBuffer.remaining();
        System.arraycopy(byteBuffer.array(), byteBuffer.arrayOffset() + byteBuffer.position(), target, offset,
                remaining);
        return remaining;
    }

    public static BytesWritable byteBufferToBytesWritable(ByteBuffer buffer) {
        return new BytesWritable(byteBufferToByteArray(buffer));
    }

    public static ByteBuffer bytesWriteableToByteBuffer(BytesWritable writable) {
        return ByteBuffer.wrap(getBytes(writable));
    }

    public static boolean wrapsFullArray(ByteBuffer byteBuffer) {
        return byteBuffer.hasArray() && byteBuffer.position() == 0 && byteBuffer.arrayOffset() == 0
                && byteBuffer.remaining() == byteBuffer.capacity();
    }

    /**
     * Always return a byte array that is a deep copy of the range represented
     * by the given ByteBuffer.
     *
     * @param byteBuffer
     * @return
     */
    public static byte[] byteBufferDeepCopy(ByteBuffer byteBuffer) {
        byte[] target = new byte[byteBuffer.remaining()];
        byteBufferToByteArray(byteBuffer, target, 0);
        return target;
    }

    public static int compareBytes(byte[] b1, byte[] b2) {
        return BYTES_COMPARATOR.compare(b1, b2);
    }

    public static byte[] getBytes(BytesWritable bw) {
        if (bw.getCapacity() == bw.getLength()) {
            return bw.getBytes();
        } else {
            return copyBytes(bw);
        }
    }

    public static byte[] copyBytes(BytesWritable bw) {
        byte[] ret = new byte[bw.getLength()];
        System.arraycopy(bw.getBytes(), 0, ret, 0, bw.getLength());
        return ret;
    }

    /**
     * Safely gets a BytesWritable field from a TupleEntry. It automatically deals
     * with padded BytesWritable.
     *
     * @param tupleEntry
     * @param fieldIndex the index of the field to be retrieved from the tuple entry
     * @return the field bytes
     */
    public static byte[] getBytes(TupleEntry tupleEntry, int fieldIndex) {
        return getBytes(tupleEntry.getTuple(), fieldIndex);
    }

    /**
     * Safely gets a BytesWritable field from a TupleEntry. It automatically deals
     * with padded BytesWritable.
     *
     * @param tupleEntry
     * @param fieldName  the tuple index of the field to be retrieved
     * @return the field bytes
     */
    public static byte[] getBytes(TupleEntry tupleEntry, String fieldName) {
        return getBytes((BytesWritable) tupleEntry.getObject(fieldName));
    }

    /**
     * Safely gets a BytesWritable field from a TupleEntry. It automatically deals
     * with padded BytesWritable.
     *
     * @param tuple
     * @param fieldIndex the index of the field to be retrieved from the tuple
     * @return the field bytes
     */
    public static byte[] getBytes(Tuple tuple, int fieldIndex) {
        return getBytes((BytesWritable) tuple.getObject(fieldIndex));
    }

    public static String encodeHex(byte[] bytes) {
        return String.valueOf(Hex.encodeHex(bytes));
    }
}