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      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_SERVERS_CAMERA_TAGMONITOR_H
     18 #define ANDROID_SERVERS_CAMERA_TAGMONITOR_H
     19 
     20 #include <vector>
     21 #include <atomic>
     22 #include <mutex>
     23 
     24 #include <utils/RefBase.h>
     25 #include <utils/String8.h>
     26 #include <utils/Timers.h>
     27 
     28 #include <media/RingBuffer.h>
     29 #include <system/camera_metadata.h>
     30 #include <system/camera_vendor_tags.h>
     31 #include <camera/CameraMetadata.h>
     32 
     33 namespace android {
     34 
     35 /**
     36  * A monitor for camera metadata values.
     37  * Tracks changes to specified metadata values over time, keeping a circular
     38  * buffer log that can be dumped at will. */
     39 class TagMonitor {
     40   public:
     41 
     42     // Monitor argument
     43     static const String16 kMonitorOption;
     44 
     45     enum eventSource {
     46         REQUEST,
     47         RESULT
     48     };
     49 
     50     TagMonitor();
     51 
     52     void initialize(metadata_vendor_id_t id) { mVendorTagId = id; }
     53 
     54     // Parse tag name list (comma-separated) and if valid, enable monitoring
     55     // If invalid, do nothing.
     56     // Recognizes "3a" as a shortcut for enabling tracking 3A state, mode, and
     57     // triggers
     58     void parseTagsToMonitor(String8 tagNames);
     59 
     60     // Disable monitoring; does not clear the event log
     61     void disableMonitoring();
     62 
     63     // Scan through the metadata and update the monitoring information
     64     void monitorMetadata(eventSource source, int64_t frameNumber,
     65             nsecs_t timestamp, const CameraMetadata& metadata);
     66 
     67     // Dump current event log to the provided fd
     68     void dumpMonitoredMetadata(int fd);
     69 
     70   private:
     71 
     72     static void printData(int fd, const uint8_t *data_ptr, uint32_t tag,
     73             int type, int count, int indentation);
     74 
     75     std::atomic<bool> mMonitoringEnabled;
     76     std::mutex mMonitorMutex;
     77 
     78     // Current tags to monitor and record changes to
     79     std::vector<uint32_t> mMonitoredTagList;
     80 
     81     // Latest-seen values of tracked tags
     82     CameraMetadata mLastMonitoredRequestValues;
     83     CameraMetadata mLastMonitoredResultValues;
     84 
     85     /**
     86      * A monitoring event
     87      * Stores a new metadata field value and the timestamp at which it changed.
     88      * Copies the source metadata value array and frees it on destruct.
     89      */
     90     struct MonitorEvent {
     91         template<typename T>
     92         MonitorEvent(eventSource src, uint32_t frameNumber, nsecs_t timestamp,
     93                 const T &newValue);
     94         ~MonitorEvent();
     95 
     96         eventSource source;
     97         uint32_t frameNumber;
     98         nsecs_t timestamp;
     99         uint32_t tag;
    100         uint8_t type;
    101         std::vector<uint8_t> newData;
    102     };
    103 
    104     // A ring buffer for tracking the last kMaxMonitorEvents metadata changes
    105     static const int kMaxMonitorEvents = 100;
    106     RingBuffer<MonitorEvent> mMonitoringEvents;
    107 
    108     // 3A fields to use with the "3a" option
    109     static const char *k3aTags;
    110     metadata_vendor_id_t mVendorTagId;
    111 };
    112 
    113 } // namespace android
    114 
    115 #endif
    116