/*
 * Copyright (C) 2016 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.Wifi
 */

package com.android.server.wifi;

import android.os.SystemClock;

import javax.annotation.concurrent.ThreadSafe;

/**
 * Wrapper class for time operations. Allows replacement of clock operations for testing.
 */
@ThreadSafe
public class Clock {

    /**
     * Get the current time of the clock in milliseconds.
     *
     * @return Current time in milliseconds.
     */
    public long getWallClockMillis() {
        return System.currentTimeMillis();
    }

    /**
     * Returns milliseconds since boot, including time spent in sleep.
     *
     * @return Current time since boot in milliseconds.
     */
    public long getElapsedSinceBootMillis() {
        return SystemClock.elapsedRealtime();
    }

   /**
     * Returns nanoseconds since boot, including time spent in sleep.
     *
     * @return Current time since boot in nanoseconds.
     */
    public long getElapsedSinceBootNanos() {
        return SystemClock.elapsedRealtimeNanos();
    }

    /**
     * Returns milliseconds since boot, not counting time spent in deep sleep.
     *
     * @return Milliseconds of non-sleep uptime since boot.
     */
    public long getUptimeSinceBootMillis() {
        return SystemClock.uptimeMillis();
    }

    /**
     * Waits a given number of milliseconds (of uptimeMillis) before returning.
     */
    public void sleep(long ms) {
        SystemClock.sleep(ms);
    }
}