power/stats: Add default implementation
Bug: 181592995
Test: atest VtsHalPowerStatsTargetTest
Change-Id: I87ea4974f857ebd126b80a45c7d7403307bceb03
diff --git a/power/stats/aidl/default/FakeEnergyMeter.h b/power/stats/aidl/default/FakeEnergyMeter.h
new file mode 100644
index 0000000..f0d4ee7
--- /dev/null
+++ b/power/stats/aidl/default/FakeEnergyMeter.h
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2021 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.
+ */
+
+#pragma once
+
+#include <PowerStats.h>
+
+#include <android-base/chrono_utils.h>
+
+#include <chrono>
+#include <random>
+
+namespace aidl {
+namespace android {
+namespace hardware {
+namespace power {
+namespace stats {
+
+class FakeEnergyMeter : public PowerStats::IEnergyMeter {
+ public:
+ FakeEnergyMeter(std::vector<std::pair<std::string, std::string>> channelNames) {
+ int32_t channelId = 0;
+ for (const auto& [name, subsystem] : channelNames) {
+ Channel c;
+ c.id = channelId++;
+ c.name = name;
+ c.subsystem = subsystem;
+
+ EnergyMeasurement m;
+ m.id = c.id;
+ m.timestampMs = 0;
+ m.durationMs = 0;
+ m.energyUWs = 0;
+
+ mChannels.push_back(c);
+ mEnergyMeasurements.push_back(m);
+ }
+ }
+ ~FakeEnergyMeter() = default;
+ ndk::ScopedAStatus readEnergyMeter(const std::vector<int32_t>& in_channelIds,
+ std::vector<EnergyMeasurement>* _aidl_return) override {
+ for (auto& measurement : mEnergyMeasurements) {
+ mFakeEnergyMeasurement.update(&measurement);
+ }
+
+ if (in_channelIds.empty()) {
+ *_aidl_return = mEnergyMeasurements;
+ } else {
+ for (int32_t id : in_channelIds) {
+ if (id >= 0 && id < mEnergyMeasurements.size()) {
+ _aidl_return->push_back(mEnergyMeasurements[id]);
+ }
+ }
+ }
+
+ return ndk::ScopedAStatus::ok();
+ }
+
+ ndk::ScopedAStatus getEnergyMeterInfo(std::vector<Channel>* _aidl_return) override {
+ *_aidl_return = mChannels;
+ return ndk::ScopedAStatus::ok();
+ }
+
+ private:
+ class FakeEnergyMeasurement {
+ public:
+ FakeEnergyMeasurement() : mDistribution(1, 100) {}
+ void update(EnergyMeasurement* measurement) {
+ // generates number in the range 1..100
+ auto randNum = std::bind(mDistribution, mGenerator);
+
+ // Get current time since boot in milliseconds
+ uint64_t now = std::chrono::time_point_cast<std::chrono::milliseconds>(
+ ::android::base::boot_clock::now())
+ .time_since_epoch()
+ .count();
+ measurement->timestampMs = now;
+ measurement->durationMs = now;
+ measurement->energyUWs += randNum() * 100;
+ }
+
+ private:
+ std::default_random_engine mGenerator;
+ std::uniform_int_distribution<int> mDistribution;
+ };
+
+ std::vector<Channel> mChannels;
+ FakeEnergyMeasurement mFakeEnergyMeasurement;
+ std::vector<EnergyMeasurement> mEnergyMeasurements;
+};
+
+} // namespace stats
+} // namespace power
+} // namespace hardware
+} // namespace android
+} // namespace aidl
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