1 /*
2  * Copyright (C) 2022 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.settings.wifi.helper;
18 
19 import android.os.Handler;
20 import android.os.HandlerThread;
21 import android.os.Process;
22 import android.os.SimpleClock;
23 import android.os.SystemClock;
24 
25 import androidx.annotation.NonNull;
26 import androidx.annotation.VisibleForTesting;
27 import androidx.lifecycle.DefaultLifecycleObserver;
28 import androidx.lifecycle.Lifecycle;
29 import androidx.lifecycle.LifecycleOwner;
30 
31 import java.time.Clock;
32 import java.time.ZoneOffset;
33 
34 /**
35  * Base class for the WifiTrackerLib related classes.
36  */
37 public class WifiTrackerBase implements DefaultLifecycleObserver {
38     private static final String TAG = "WifiTrackerBase";
39 
40     // Max age of tracked WifiEntries
41     protected static final long MAX_SCAN_AGE_MILLIS = 15_000;
42     // Interval between initiating Wi-Fi Tracker scans
43     protected static final long SCAN_INTERVAL_MILLIS = 10_000;
44     // Clock used for evaluating the age of scans
45     protected static final Clock ELAPSED_REALTIME_CLOCK = new SimpleClock(ZoneOffset.UTC) {
46         @Override
47         public long millis() {
48             return SystemClock.elapsedRealtime();
49         }
50     };
51 
52     @VisibleForTesting
53     protected HandlerThread mWorkerThread;
54 
WifiTrackerBase(@onNull Lifecycle lifecycle)55     public WifiTrackerBase(@NonNull Lifecycle lifecycle) {
56         this(lifecycle, null /* handlerThread */);
57     }
58 
59     @VisibleForTesting
WifiTrackerBase(@onNull Lifecycle lifecycle, HandlerThread handlerThread)60     protected WifiTrackerBase(@NonNull Lifecycle lifecycle, HandlerThread handlerThread) {
61         lifecycle.addObserver(this);
62         mWorkerThread = (handlerThread != null) ? handlerThread :
63                 new HandlerThread(getTag()
64                         + "{" + Integer.toHexString(System.identityHashCode(this)) + "}",
65                         Process.THREAD_PRIORITY_BACKGROUND);
66         mWorkerThread.start();
67     }
68 
getTag()69     protected String getTag() {
70         return TAG;
71     }
72 
73     @Override
onDestroy(@onNull LifecycleOwner owner)74     public void onDestroy(@NonNull LifecycleOwner owner) {
75         mWorkerThread.quit();
76     }
77 
78     /** Returns the worker thread handler. */
getWorkerThreadHandler()79     public Handler getWorkerThreadHandler() {
80         return mWorkerThread.getThreadHandler();
81     }
82 }
83