Java ByteBuffer Extract extractSingleHighCardDims(byte[] highCardArr, int index, int highCardinalityCount, ByteBuffer outBuffer)

Description

This method will extract the single dimension from the complete high card dims byte[].+ The format of the byte [] will be, Totallength,CompleteStartOffsets,Dat

License

Apache License

Parameter

Parameter	Description
highCardArr	a parameter
index	a parameter
highCardinalityCount	a parameter
outBuffer	a parameter

Declaration

public static void extractSingleHighCardDims(byte[] highCardArr,
        int index, int highCardinalityCount, ByteBuffer outBuffer) 

Method Source Code

//package com.java2s;
/*//from  w  ww.j  a  v  a  2 s. c  o  m
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

import java.nio.ByteBuffer;

public class Main {
    /**
     * This method will extract the single dimension from the complete high card dims byte[].+     *
     * The format of the byte [] will be,  Totallength,CompleteStartOffsets,Dat
     *
     * @param highCardArr
     * @param index
     * @param highCardinalityCount
     * @param outBuffer
     */
    public static void extractSingleHighCardDims(byte[] highCardArr,
            int index, int highCardinalityCount, ByteBuffer outBuffer) {
        ByteBuffer buff = null;
        short secIndex = 0;
        short firstIndex = 0;
        int length;
        // if the requested index is a last one then we need to calculate length
        // based on byte[] length.
        if (index == highCardinalityCount - 1) {
            // need to read 2 bytes(1 short) to determine starting offset and
            // length can be calculated by array length.
            buff = ByteBuffer.wrap(highCardArr, (index * 2) + 2, 2);
        } else {
            // need to read 4 bytes(2 short) to determine starting offset and
            // length.
            buff = ByteBuffer.wrap(highCardArr, (index * 2) + 2, 4);
        }

        firstIndex = buff.getShort();
        // if it is a last dimension in high card then this will be last
        // offset.so calculate length from total length
        if (index == highCardinalityCount - 1) {
            secIndex = (short) highCardArr.length;
        } else {
            secIndex = buff.getShort();
        }

        length = secIndex - firstIndex;

        outBuffer.position(firstIndex);
        outBuffer.limit(outBuffer.position() + length);

    }
}

Related

1. extract(ByteBuffer buf)
2. extractBytes(ByteBuffer buf)
3. extractBytes(ByteBuffer buffer, int size)
4. extractBytes(ByteBuffer byteBuffer, byte startByte, byte endByte)