/*
* 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.hadoop.hbase.codec.prefixtree.encode.tokenize;
import java.util.Comparator;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
/**
* Determines order of nodes in the output array. Maybe possible to optimize further.
*/
@InterfaceAudience.Private
public class TokenDepthComparator implements Comparator<TokenizerNode> {
@Override
public int compare(TokenizerNode a, TokenizerNode b) {
if(a==null){
throw new IllegalArgumentException("a cannot be null");
}
if(b==null){
throw new IllegalArgumentException("b cannot be null");
}
// put leaves at the end
if (!a.isLeaf() && b.isLeaf()) {
return -1;
}
if (a.isLeaf() && !b.isLeaf()) {
return 1;
}
if (a.isLeaf() && b.isLeaf()) {// keep leaves in sorted order (for debugability)
return a.getId() < b.getId() ? -1 : 1;
}
// compare depth
if (a.getTokenOffset() < b.getTokenOffset()) {
return -1;
}
if (a.getTokenOffset() > b.getTokenOffset()) {
return 1;
}
// if same depth, return lower id first. ids are unique
return a.getId() < b.getId() ? -1 : 1;
}
}