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/*
* Copyright (C) 2021 The Android Open Source Project
*
* 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.android.systemui.media.controls.util;
import java.util.Objects;
/**
* A simple hash function for use in privacy-sensitive logging.
*/
public final class SmallHash {
// Hashes will be in the range [0, MAX_HASH).
public static final int MAX_HASH = (1 << 13);
/** Return Small hash of the string, if non-null, or 0 otherwise. */
public static int hash(String in) {
return hash(Objects.hashCode(in));
}
/**
* Maps in to the range [0, MAX_HASH), keeping similar values distinct.
*
* @param in An arbitrary integer.
* @return in mod MAX_HASH, signs chosen to stay in the range [0, MAX_HASH).
*/
public static int hash(int in) {
return Math.abs(Math.floorMod(in, MAX_HASH));
}
private SmallHash() {}
}
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