1 /*
2  * Copyright (C) 2017 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 android.app.usage;
18 
19 import android.annotation.SystemApi;
20 import android.app.Service;
21 import android.app.usage.ICacheQuotaService;
22 import android.content.Intent;
23 import android.os.Bundle;
24 import android.os.Handler;
25 import android.os.IBinder;
26 import android.os.Looper;
27 import android.os.Message;
28 import android.os.RemoteCallback;
29 import android.util.Log;
30 import android.util.Pair;
31 
32 import java.util.List;
33 
34 /**
35  * CacheQuoteService defines a service which accepts cache quota requests and processes them,
36  * thereby filling out how much quota each request deserves.
37  * {@hide}
38  */
39 @SystemApi
40 public abstract class CacheQuotaService extends Service {
41     private static final String TAG = "CacheQuotaService";
42 
43     /**
44      * The {@link Intent} action that must be declared as handled by a service
45      * in its manifest for the system to recognize it as a quota providing service.
46      */
47     public static final String SERVICE_INTERFACE = "android.app.usage.CacheQuotaService";
48 
49     /** {@hide} **/
50     public static final String REQUEST_LIST_KEY = "requests";
51 
52     private CacheQuotaServiceWrapper mWrapper;
53     private Handler mHandler;
54 
55     @Override
onCreate()56     public void onCreate() {
57         super.onCreate();
58         mWrapper = new CacheQuotaServiceWrapper();
59         mHandler = new ServiceHandler(getMainLooper());
60     }
61 
62     @Override
onBind(Intent intent)63     public IBinder onBind(Intent intent) {
64         return mWrapper;
65     }
66 
67     /**
68      * Processes the cache quota list upon receiving a list of requests.
69      * @param requests A list of cache quotas to fulfill.
70      * @return A completed list of cache quota requests.
71      */
onComputeCacheQuotaHints( List<CacheQuotaHint> requests)72     public abstract List<CacheQuotaHint> onComputeCacheQuotaHints(
73             List<CacheQuotaHint> requests);
74 
75     private final class CacheQuotaServiceWrapper extends ICacheQuotaService.Stub {
76         @Override
computeCacheQuotaHints( RemoteCallback callback, List<CacheQuotaHint> requests)77         public void computeCacheQuotaHints(
78                 RemoteCallback callback, List<CacheQuotaHint> requests) {
79             final Pair<RemoteCallback, List<CacheQuotaHint>> pair =
80                     Pair.create(callback, requests);
81             Message msg = mHandler.obtainMessage(ServiceHandler.MSG_SEND_LIST, pair);
82             mHandler.sendMessage(msg);
83         }
84     }
85 
86     private final class ServiceHandler extends Handler {
87         public static final int MSG_SEND_LIST = 1;
88 
ServiceHandler(Looper looper)89         public ServiceHandler(Looper looper) {
90             super(looper, null, true);
91         }
92 
93         @Override
handleMessage(Message msg)94         public void handleMessage(Message msg) {
95             final int action = msg.what;
96             switch (action) {
97                 case MSG_SEND_LIST:
98                     final Pair<RemoteCallback, List<CacheQuotaHint>> pair =
99                             (Pair<RemoteCallback, List<CacheQuotaHint>>) msg.obj;
100                     List<CacheQuotaHint> processed = onComputeCacheQuotaHints(pair.second);
101                     final Bundle data = new Bundle();
102                     data.putParcelableList(REQUEST_LIST_KEY, processed);
103 
104                     final RemoteCallback callback = pair.first;
105                     callback.sendResult(data);
106                     break;
107                 default:
108                     Log.w(TAG, "Handling unknown message: " + action);
109             }
110         }
111     }
112 }
113