1 /*
2  * Copyright (C) 2023 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.metrics;
18 
19 import android.annotation.NonNull;
20 import android.app.StatsManager;
21 import android.content.Context;
22 import android.os.Handler;
23 import android.util.Log;
24 import android.util.StatsEvent;
25 
26 import com.android.modules.utils.HandlerExecutor;
27 
28 import java.util.List;
29 import java.util.function.Supplier;
30 
31 /**
32  * A class to register, sample and send connectivity state metrics.
33  */
34 public class ConnectivitySampleMetricsHelper implements StatsManager.StatsPullAtomCallback {
35     private static final String TAG = ConnectivitySampleMetricsHelper.class.getSimpleName();
36 
37     final Supplier<StatsEvent> mDelegate;
38 
39     /**
40      * Start collecting metrics.
41      * @param context some context to get services
42      * @param connectivityServiceHandler the connectivity service handler
43      * @param atomTag the tag to collect metrics from
44      * @param delegate a method returning data when called on the handler thread
45      */
46     // Unfortunately it seems essentially impossible to unit test this method. The only thing
47     // to test is that there is a call to setPullAtomCallback, but StatsManager is final and
48     // can't be mocked without mockito-extended. Using mockito-extended in FrameworksNetTests
49     // would have a very large impact on performance, while splitting the unit test for this
50     // class in a separate target would make testing very hard to manage. Therefore, there
51     // can unfortunately be no unit tests for this method, but at least it is very simple.
start(@onNull final Context context, @NonNull final Handler connectivityServiceHandler, final int atomTag, @NonNull final Supplier<StatsEvent> delegate)52     public static void start(@NonNull final Context context,
53             @NonNull final Handler connectivityServiceHandler,
54             final int atomTag,
55             @NonNull final Supplier<StatsEvent> delegate) {
56         final ConnectivitySampleMetricsHelper metrics =
57                 new ConnectivitySampleMetricsHelper(delegate);
58         final StatsManager mgr = context.getSystemService(StatsManager.class);
59         if (null == mgr) return; // No metrics for you
60         mgr.setPullAtomCallback(atomTag, null /* metadata */,
61                 new HandlerExecutor(connectivityServiceHandler), metrics);
62     }
63 
ConnectivitySampleMetricsHelper(@onNull final Supplier<StatsEvent> delegate)64     public ConnectivitySampleMetricsHelper(@NonNull final Supplier<StatsEvent> delegate) {
65         mDelegate = delegate;
66     }
67 
68     @Override
onPullAtom(final int atomTag, final List<StatsEvent> data)69     public int onPullAtom(final int atomTag, final List<StatsEvent> data) {
70         Log.d(TAG, "Sampling data for atom : " + atomTag);
71         data.add(mDelegate.get());
72         return StatsManager.PULL_SUCCESS;
73     }
74 }
75