/*
* 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.brooklyn.util.net;
import java.util.Collection;
/**
* Given several strings, determines which have the longest, and shorted, initial matching prefix.
* Particularly useful as a poor-man's way to determine which IP's are likely to be the same subnet.
*/
public class NetworkMultiAddressUtils {
// TODO should convert to byte arrays then binary, and look at binary digit match length !
// public static Collection<String> sortByInitialSimilarity(final String pattern, Collection<String> targets) {
// List<String> result = new ArrayList<String>(targets);
// Collections.sort(result, new Comparator<String>() {
// @Override
// public int compare(String o1, String o2) {
// int i1 = 0; int i2 = 0;
// for (int i=0; i<pattern.length(); i++) {
// if (o1.length()<i || o2.length()<i) break;
// if (o1.substring(0, i).equals(anObject))
// }
// }
// });
// return result;
// }
public static String getClosest(final String pattern, Collection<String> targets) {
int score = -1;
String best = null;
for (String target: targets) {
int thisScore = matchLength(pattern, target);
if (thisScore > score) {
score = thisScore;
best = target;
}
}
return best;
}
public static String getFurthest(final String pattern, Collection<String> targets) {
int score = 65535;
String best = null;
for (String target: targets) {
int thisScore = matchLength(pattern, target);
if (thisScore < score) {
score = thisScore;
best = target;
}
}
return best;
}
private static int matchLength(String pattern, String target) {
int i=0;
while (i<pattern.length() && i<target.length() && pattern.charAt(i)==target.charAt(i))
i++;
return i;
}
}