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_SENSOR_LIST_H
18 #define ANDROID_SENSOR_SERVICE_UTIL_SENSOR_LIST_H
19 
20 #include "SensorInterface.h"
21 #include "SensorServiceUtils.h"
22 
23 #include <gui/Sensor.h>
24 #include <utils/String8.h>
25 #include <utils/Vector.h>
26 
27 #include <map>
28 #include <mutex>
29 #include <unordered_set>
30 #include <vector>
31 
32 namespace android {
33 class SensorInterface;
34 
35 namespace SensorServiceUtil {
36 
37 class SensorList : public Dumpable {
38 public:
39     // After SensorInterface * is added into SensorList, it can be assumed that SensorList own the
40     // object it pointed to and the object should not be released elsewhere.
41     bool add(int handle, SensorInterface* si, bool isForDebug = false, bool isVirtual = false);
42 
43     // After a handle is removed, the object that SensorInterface * pointing to may get deleted if
44     // no more sp<> of the same object exist.
45     bool remove(int handle);
46 
hasAnySensor()47     inline bool hasAnySensor() const { return mHandleMap.size() > 0;}
48 
49     //helper functions
50     const Vector<Sensor> getUserSensors() const;
51     const Vector<Sensor> getUserDebugSensors() const;
52     const Vector<Sensor> getDynamicSensors() const;
53     const Vector<Sensor> getVirtualSensors() const;
54 
55     String8 getName(int handle) const;
56     sp<SensorInterface> getInterface(int handle) const;
57     bool isNewHandle(int handle) const;
58 
59     // Iterate through Sensor in sensor list and perform operation f on each Sensor object.
60     //
61     // TF is a function with the signature:
62     //    bool f(const Sensor &);
63     // A return value of 'false' stops the iteration immediately.
64     //
65     // Note: in the function f, it is illegal to make calls to member functions of the same
66     // SensorList object on which forEachSensor is invoked.
67     template <typename TF>
68     void forEachSensor(const TF& f) const;
69 
getNonSensor()70     const Sensor& getNonSensor() const { return mNonSensor;}
71 
72     // Dumpable interface
73     virtual std::string dump() const override;
74 
75     virtual ~SensorList();
76 private:
77     struct Entry {
78         sp<SensorInterface> si;
79         const bool isForDebug;
80         const bool isVirtual;
EntryEntry81         Entry(SensorInterface* si_, bool debug_, bool virtual_) :
82             si(si_), isForDebug(debug_), isVirtual(virtual_) {
83         }
84     };
85 
86     const static Sensor mNonSensor; //.getName() == "unknown",
87 
88     // Iterate through Entry in sensor list and perform operation f on each Entry.
89     //
90     // TF is a function with the signature:
91     //    bool f(const Entry &);
92     // A return value of 'false' stops the iteration over entries immediately.
93     //
94     // Note: in the function being passed in, it is illegal to make calls to member functions of the
95     // same SensorList object on which forEachSensor is invoked.
96     template <typename TF>
97     void forEachEntry(const TF& f) const;
98 
99     template <typename T, typename TF>
100     T getOne(int handle, const TF& accessor, T def = T()) const;
101 
102     mutable std::mutex mLock;
103     std::map<int, Entry> mHandleMap;
104     std::unordered_set<int> mUsedHandle;
105 };
106 
107 template <typename TF>
forEachSensor(const TF & f)108 void SensorList::forEachSensor(const TF& f) const {
109     // lock happens in forEachEntry
110     forEachEntry([&f] (const Entry& e) -> bool { return f(e.si->getSensor());});
111 }
112 
113 template <typename TF>
forEachEntry(const TF & f)114 void SensorList::forEachEntry(const TF& f) const {
115     std::lock_guard<std::mutex> lk(mLock);
116 
117     for (auto&& i : mHandleMap) {
118         if (!f(i.second)){
119             break;
120         }
121     }
122 }
123 
124 template <typename T, typename TF>
getOne(int handle,const TF & accessor,T def)125 T SensorList::getOne(int handle, const TF& accessor, T def) const {
126     std::lock_guard<std::mutex> lk(mLock);
127     auto i = mHandleMap.find(handle);
128     if (i != mHandleMap.end()) {
129         return accessor(i->second);
130     } else {
131         return def;
132     }
133 }
134 
135 } // namespace SensorServiceUtil
136 } // namespace android
137 
138 #endif // ANDROID_SENSOR_SERVICE_UTIL_SENSOR_LIST_H
139