/*
* Copyright 2015-present Facebook, Inc.
*
* Licensed 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 com.facebook.buck.hashing;
import com.google.common.hash.Hasher;
public class StringHashing {
// Utility class, do not instantiate.
private StringHashing() {}
/**
* Encodes the length of the string in UTF-16 code units, then the UTF-16 code units of the
* string.
*
* <p>Useful to ensure hash codes are different when multiple strings are hashed in order ("foo"
* then "bar" should hash differently from "foobar").
*/
public static void hashStringAndLength(Hasher hasher, String string) {
// We used to hash the UTF-8 bytes of the string, but it takes
// a lot of unnecessary CPU and memory to do so.
hasher.putInt(string.length());
hasher.putUnencodedChars(string);
}
}