services/devicepolicy/java/com/android/server/devicepolicy/SetUnion.java

/*
 * Copyright (C) 2022 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.server.devicepolicy;

import android.annotation.NonNull;

import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.Objects;
import java.util.Set;

final class SetUnion<V> extends ResolutionMechanism<Set<V>> {

    @Override
    Set<V> resolve(@NonNull LinkedHashMap<EnforcingAdmin, Set<V>> adminPolicies) {
        Objects.requireNonNull(adminPolicies);
        if (adminPolicies.isEmpty()) {
            return null;
        }
        Set<V> unionOfPolicies = new HashSet<>();
        for (Set<V> policy : adminPolicies.values()) {
            unionOfPolicies.addAll(policy);
        }
        return unionOfPolicies;
    }

    @Override
    public String toString() {
        return "SetUnion {}";
    }
}