Java tutorial
/* * 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. */ package org.apache.kylin.storage.hbase.common.coprocessor; import java.util.Arrays; import java.util.LinkedList; import org.apache.kylin.common.util.BytesUtil; import org.apache.kylin.dimension.FixedLenDimEnc; import com.google.common.collect.Lists; /** */ public class AggrKey implements Comparable<AggrKey> { final byte[] groupByMask; final transient int[] groupByMaskSet; transient int hashcode; byte[] data; int offset; AggrKey(byte[] groupByMask) { this.groupByMask = groupByMask; LinkedList<Integer> list = Lists.newLinkedList(); for (int i = 0; i < groupByMask.length; i++) { if (groupByMask[i] != 0) { list.add(i); } } groupByMaskSet = new int[list.size()]; for (int i = 0; i < list.size(); i++) { groupByMaskSet[i] = list.get(i); } } private AggrKey(byte[] groupByMask, int[] groupByMaskSet, byte[] data, int offset, int hashcode) { this.groupByMask = groupByMask; this.groupByMaskSet = groupByMaskSet; this.data = data; this.offset = offset; this.hashcode = hashcode; } private int calculateHash() { int hash = 1; for (int i = 0; i < groupByMaskSet.length; i++) { byte t = data[offset + groupByMaskSet[i]]; if (t != FixedLenDimEnc.ROWKEY_PLACE_HOLDER_BYTE) { hash = (31 * hash) + t; } } return hash; } public byte[] get() { return data; } public int offset() { return offset; } public int length() { return groupByMask.length; } void set(byte[] data, int offset) { this.data = data; this.offset = offset; this.hashcode = calculateHash(); } public byte[] getGroupByMask() { return this.groupByMask; } public byte[] copyBytes() { return Arrays.copyOfRange(data, offset, offset + length()); } AggrKey copy() { AggrKey copy = new AggrKey(this.groupByMask, this.groupByMaskSet, copyBytes(), 0, this.hashcode); return copy; } @Override public int hashCode() { return hashcode; } @Override public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass() != obj.getClass()) return false; AggrKey other = (AggrKey) obj; return compareTo(other) == 0; } @Override public int compareTo(AggrKey o) { int comp = this.length() - o.length(); if (comp != 0) return comp; for (int i = 0; i < groupByMaskSet.length; i++) { comp = BytesUtil.compareByteUnsigned(this.data[this.offset + groupByMaskSet[i]], o.data[o.offset + groupByMaskSet[i]]); if (comp != 0) return comp; } return 0; } }