1/*
2 * Copyright (C) 2016 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#ifndef ANDROID_SENSOR_SERVICE_UTIL_RECENT_EVENT_LOGGER_H
18#define ANDROID_SENSOR_SERVICE_UTIL_RECENT_EVENT_LOGGER_H
19
20#include "RingBuffer.h"
21#include "SensorServiceUtils.h"
22
23#include <hardware/sensors.h>
24#include <utils/String8.h>
25
26#include <mutex>
27
28namespace android {
29namespace SensorServiceUtil {
30
31// A circular buffer that record the last N events of a sensor type for debugging. The size of this
32// buffer depends on sensor type and is controlled by logSizeBySensorType(). The last N events
33// generated from the sensor are stored in this buffer.  The buffer is NOT cleared when the sensor
34// unregisters and as a result very old data in the dumpsys output can be seen, which is an intended
35// behavior.
36class RecentEventLogger : public Dumpable {
37public:
38    explicit RecentEventLogger(int sensorType);
39    void addEvent(const sensors_event_t& event);
40    bool populateLastEvent(sensors_event_t *event) const;
41    bool isEmpty() const;
42    virtual ~RecentEventLogger() {}
43
44    // Dumpable interface
45    virtual std::string dump() const override;
46    virtual void setFormat(std::string format) override;
47
48protected:
49    struct SensorEventLog {
50        explicit SensorEventLog(const sensors_event_t& e);
51        timespec mWallTime;
52        sensors_event_t mEvent;
53    };
54
55    const int mSensorType;
56    const size_t mEventSize;
57
58    mutable std::mutex mLock;
59    RingBuffer<SensorEventLog> mRecentEvents;
60
61    bool mMaskData;
62
63private:
64    static size_t logSizeBySensorType(int sensorType);
65};
66
67} // namespace SensorServiceUtil
68} // namespace android;
69
70#endif // ANDROID_SENSOR_SERVICE_UTIL_RECENT_EVENT_LOGGER_H
71
72