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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     enum eventSource {
42         REQUEST,
43         RESULT
44     };
45 
46     TagMonitor();
47 
initialize(metadata_vendor_id_t id)48     void initialize(metadata_vendor_id_t id) { mVendorTagId = id; }
49 
50     // Parse tag name list (comma-separated) and if valid, enable monitoring
51     // If invalid, do nothing.
52     // Recognizes "3a" as a shortcut for enabling tracking 3A state, mode, and
53     // triggers
54     void parseTagsToMonitor(String8 tagNames);
55 
56     // Disable monitoring; does not clear the event log
57     void disableMonitoring();
58 
59     // Scan through the metadata and update the monitoring information
60     void monitorMetadata(eventSource source, int64_t frameNumber,
61             nsecs_t timestamp, const CameraMetadata& metadata);
62 
63     // Dump current event log to the provided fd
64     void dumpMonitoredMetadata(int fd);
65 
66   private:
67 
68     static void printData(int fd, const uint8_t *data_ptr, uint32_t tag,
69             int type, int count, int indentation);
70 
71     std::atomic<bool> mMonitoringEnabled;
72     std::mutex mMonitorMutex;
73 
74     // Current tags to monitor and record changes to
75     std::vector<uint32_t> mMonitoredTagList;
76 
77     // Latest-seen values of tracked tags
78     CameraMetadata mLastMonitoredRequestValues;
79     CameraMetadata mLastMonitoredResultValues;
80 
81     /**
82      * A monitoring event
83      * Stores a new metadata field value and the timestamp at which it changed.
84      * Copies the source metadata value array and frees it on destruct.
85      */
86     struct MonitorEvent {
87         template<typename T>
88         MonitorEvent(eventSource src, uint32_t frameNumber, nsecs_t timestamp,
89                 const T &newValue);
90         ~MonitorEvent();
91 
92         eventSource source;
93         uint32_t frameNumber;
94         nsecs_t timestamp;
95         uint32_t tag;
96         uint8_t type;
97         std::vector<uint8_t> newData;
98     };
99 
100     // A ring buffer for tracking the last kMaxMonitorEvents metadata changes
101     static const int kMaxMonitorEvents = 100;
102     RingBuffer<MonitorEvent> mMonitoringEvents;
103 
104     // 3A fields to use with the "3a" option
105     static const char *k3aTags;
106     metadata_vendor_id_t mVendorTagId;
107 };
108 
109 } // namespace android
110 
111 #endif
112