1 /*
2  * Copyright (C) 2021 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 #pragma once
18 
19 #include <PowerStats.h>
20 
21 #include <android-base/chrono_utils.h>
22 
23 #include <chrono>
24 #include <random>
25 
26 namespace aidl {
27 namespace android {
28 namespace hardware {
29 namespace power {
30 namespace stats {
31 
32 class FakeEnergyMeter : public PowerStats::IEnergyMeter {
33   public:
FakeEnergyMeter(std::vector<std::pair<std::string,std::string>> channelNames)34     FakeEnergyMeter(std::vector<std::pair<std::string, std::string>> channelNames) {
35         int32_t channelId = 0;
36         for (const auto& [name, subsystem] : channelNames) {
37             Channel c;
38             c.id = channelId++;
39             c.name = name;
40             c.subsystem = subsystem;
41 
42             EnergyMeasurement m;
43             m.id = c.id;
44             m.timestampMs = 0;
45             m.durationMs = 0;
46             m.energyUWs = 0;
47 
48             mChannels.push_back(c);
49             mEnergyMeasurements.push_back(m);
50         }
51     }
52     ~FakeEnergyMeter() = default;
readEnergyMeter(const std::vector<int32_t> & in_channelIds,std::vector<EnergyMeasurement> * _aidl_return)53     ndk::ScopedAStatus readEnergyMeter(const std::vector<int32_t>& in_channelIds,
54                                        std::vector<EnergyMeasurement>* _aidl_return) override {
55         for (auto& measurement : mEnergyMeasurements) {
56             mFakeEnergyMeasurement.update(&measurement);
57         }
58 
59         if (in_channelIds.empty()) {
60             *_aidl_return = mEnergyMeasurements;
61         } else {
62             for (int32_t id : in_channelIds) {
63                 // check for invalid ids
64                 if (id < 0 || id >= mEnergyMeasurements.size()) {
65                     return ndk::ScopedAStatus(AStatus_fromExceptionCode(EX_ILLEGAL_ARGUMENT));
66                 }
67 
68                 _aidl_return->push_back(mEnergyMeasurements[id]);
69             }
70         }
71 
72         return ndk::ScopedAStatus::ok();
73     }
74 
getEnergyMeterInfo(std::vector<Channel> * _aidl_return)75     ndk::ScopedAStatus getEnergyMeterInfo(std::vector<Channel>* _aidl_return) override {
76         *_aidl_return = mChannels;
77         return ndk::ScopedAStatus::ok();
78     }
79 
80   private:
81     class FakeEnergyMeasurement {
82       public:
FakeEnergyMeasurement()83         FakeEnergyMeasurement() : mDistribution(1, 100) {}
update(EnergyMeasurement * measurement)84         void update(EnergyMeasurement* measurement) {
85             // generates number in the range 1..100
86             auto randNum = std::bind(mDistribution, mGenerator);
87 
88             // Get current time since boot in milliseconds
89             uint64_t now = std::chrono::time_point_cast<std::chrono::milliseconds>(
90                                    ::android::base::boot_clock::now())
91                                    .time_since_epoch()
92                                    .count();
93             measurement->timestampMs = now;
94             measurement->durationMs = now;
95             measurement->energyUWs += randNum() * 100;
96         }
97 
98       private:
99         std::default_random_engine mGenerator;
100         std::uniform_int_distribution<int> mDistribution;
101     };
102 
103     std::vector<Channel> mChannels;
104     FakeEnergyMeasurement mFakeEnergyMeasurement;
105     std::vector<EnergyMeasurement> mEnergyMeasurements;
106 };
107 
108 }  // namespace stats
109 }  // namespace power
110 }  // namespace hardware
111 }  // namespace android
112 }  // namespace aidl