package org.apache.lucene.util;
/*
* 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.
*/
/**
* Math static utility methods.
*/
public final class MathUtil {
// No instance:
private MathUtil() {
}
/**
* Returns {@code x <= 0 ? 0 : Math.floor(Math.log(x) / Math.log(base))}
* @param base must be {@code > 1}
*/
public static int log(long x, int base) {
if (base <= 1) {
throw new IllegalArgumentException("base must be > 1");
}
int ret = 0;
while (x >= base) {
x /= base;
ret++;
}
return ret;
}
}