services/flags/java/com/android/server/flags/FeatureFlagsService.java

/*
 * Copyright (C) 2023 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.flags;

import android.content.Context;
import android.util.Slog;

import com.android.server.SystemService;

/**
 * A service that manages syncing {@link android.flags.FeatureFlags} across processes.
 *
 * This service holds flags stable for at least the lifetime of a process, meaning that if
 * a process comes online with a flag set to true, any other process that connects here and
 * tries to read the same flag will also receive the flag as true. The flag will remain stable
 * until either all of the interested processes have died, or the device restarts.
 *
 * TODO(279054964): Add to dumpsys
 * @hide
 */
public class FeatureFlagsService extends SystemService {

    static final String TAG = "FeatureFlagsService";
    private final FlagOverrideStore mFlagStore;
    private final FlagsShellCommand mShellCommand;

    /**
     * Initializes the system service.
     *
     * @param context The system server context.
     */
    public FeatureFlagsService(Context context) {
        super(context);
        mFlagStore = new FlagOverrideStore(
                new GlobalSettingsProxy(context.getContentResolver()));
        mShellCommand = new FlagsShellCommand(mFlagStore);
    }

    @Override
    public void onStart() {
        Slog.d(TAG, "Started Feature Flag Service");
        publishBinderService(
                Context.FEATURE_FLAGS_SERVICE, new FeatureFlagsBinder(mFlagStore, mShellCommand));
    }

}