1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 package org.apache.hadoop.hbase.codec.prefixtree.encode.tokenize; 20 21 import java.util.Comparator; 22 23 import org.apache.hadoop.hbase.classification.InterfaceAudience; 24 25 /** 26 * Determines order of nodes in the output array. Maybe possible to optimize further. 27 */ 28 @InterfaceAudience.Private 29 public class TokenDepthComparator implements Comparator<TokenizerNode> { 30 31 @Override 32 public int compare(TokenizerNode a, TokenizerNode b) { 33 if(a==null){ 34 throw new IllegalArgumentException("a cannot be null"); 35 } 36 if(b==null){ 37 throw new IllegalArgumentException("b cannot be null"); 38 } 39 40 // put leaves at the end 41 if (!a.isLeaf() && b.isLeaf()) { 42 return -1; 43 } 44 if (a.isLeaf() && !b.isLeaf()) { 45 return 1; 46 } 47 48 if (a.isLeaf() && b.isLeaf()) {// keep leaves in sorted order (for debugability) 49 return a.getId() < b.getId() ? -1 : 1; 50 } 51 52 // compare depth 53 if (a.getTokenOffset() < b.getTokenOffset()) { 54 return -1; 55 } 56 if (a.getTokenOffset() > b.getTokenOffset()) { 57 return 1; 58 } 59 60 // if same depth, return lower id first. ids are unique 61 return a.getId() < b.getId() ? -1 : 1; 62 } 63 64 }