Merge "Moving GNSS related code in class LocationManagerService into its own...

/*

 * Copyright (C) 2019 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;

import android.annotation.NonNull;

import android.app.ActivityManager;

import android.content.Context;

import android.os.IBinder;

import android.os.RemoteException;

import android.util.Log;

import com.android.server.location.CallerIdentity;

import java.util.NoSuchElementException;

import java.util.function.Consumer;

/**

 * Shared utilities for LocationManagerService and GnssManager.

 */

public class LocationManagerServiceUtils {

    private static final String TAG = "LocManagerServiceUtils";

    private static final boolean D = Log.isLoggable(TAG, Log.DEBUG);

    /**

     * Listener that can be linked to a binder.

     * @param <TListener> listener type

     */

    public static class LinkedListener<TListener> extends

            LinkedListenerBase {

        private final TListener mListener;

        private final Consumer<TListener> mBinderDeathCallback;

        public LinkedListener(

                @NonNull TListener listener,

                String listenerName,

                @NonNull CallerIdentity callerIdentity,

                @NonNull Consumer<TListener> binderDeathCallback) {

            super(callerIdentity, listenerName);

            mListener = listener;

            mBinderDeathCallback = binderDeathCallback;

        }

        @Override

        public void binderDied() {

            if (D) Log.d(TAG, "Remote " + mListenerName + " died.");

            mBinderDeathCallback.accept(mListener);

        }

    }

    /**

     * Skeleton class of listener that can be linked to a binder.

     */

    public abstract static class LinkedListenerBase implements IBinder.DeathRecipient {

        protected final CallerIdentity mCallerIdentity;

        protected final String mListenerName;

        LinkedListenerBase(

                @NonNull CallerIdentity callerIdentity, @NonNull String listenerName) {

            mCallerIdentity = callerIdentity;

            mListenerName = listenerName;

        }

        @Override

        public String toString() {

            return mListenerName + "[" + mCallerIdentity.mPackageName + "(" + mCallerIdentity.mPid

                    + ")]";

        }

        public CallerIdentity getCallerIdentity() {

            return mCallerIdentity;

        }

        public String getListenerName() {

            return mListenerName;

        }

        /**

         * Link listener (i.e. callback) to a binder, so that it will be called upon binder's death.

         *

         * @param binder that calls listener upon death

         * @return true if listener is successfully linked to binder, false otherwise

         */

        public boolean linkToListenerDeathNotificationLocked(

                IBinder binder) {

            try {

                binder.linkToDeath(this, 0 /* flags */);

                return true;

            } catch (RemoteException e) {

                // if the remote process registering the listener is already dead, just swallow the

                // exception and return

                Log.w(TAG, "Could not link " + mListenerName + " death callback.", e);

                return false;

            }

        }

        /**

         * Unlink death listener (i.e. callback) from binder.

         *

         * @param binder that calls listener upon death

         * @return true if binder is successfully unlinked from binder, false otherwise

         */

        public boolean unlinkFromListenerDeathNotificationLocked(

                IBinder binder) {

            try {

                binder.unlinkToDeath(this, 0 /* flags */);

                return true;

            } catch (NoSuchElementException e) {

                // if the death callback isn't connected (it should be...), log error,

                // swallow the exception and return

                Log.w(TAG, "Could not unlink " + mListenerName + " death callback.", e);

                return false;

            }

        }

    }

    /**

     * Convert boolean foreground into "foreground" or "background" string.

     *

     * @param foreground boolean indicating foreground

     * @return "foreground" string if true, false otherwise

     */

    public static String foregroundAsString(boolean foreground) {

        return foreground ? "foreground" : "background";

    }

    /**

     * Classifies importance level as foreground or not.

     *

     * @param importance level as int

     * @return boolean indicating if importance level is foreground or greater

     */

    public static boolean isImportanceForeground(int importance) {

        return importance <= ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND_SERVICE;

    }

    /**

     * Get package importance level.

     *

     * @param packageName package name

     * @return package importance level as int

     */

    public static int getPackageImportance(String packageName, Context context) {

        return ((ActivityManager) context.getSystemService(

                Context.ACTIVITY_SERVICE)).getPackageImportance(packageName);

    }

}