1 /*
2  * Copyright (c) 2023 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #ifndef IAM_FINITE_STATE_MACHINE_IMPL_H
17 #define IAM_FINITE_STATE_MACHINE_IMPL_H
18 
19 #include <cstdint>
20 #include <memory>
21 #include <mutex>
22 #include <queue>
23 #include <string>
24 #include <unordered_map>
25 
26 #include "nocopyable.h"
27 #include "safe_queue.h"
28 
29 #include "finite_state_machine.h"
30 #include "thread_handler.h"
31 
32 namespace OHOS {
33 namespace UserIam {
34 namespace FaceAuth {
35 class FiniteStateMachineImpl final : public FiniteStateMachine,
36                                      public std::enable_shared_from_this<FiniteStateMachineImpl>,
37                                      public NoCopyable {
38 public:
39     class Inner;
40     using TransitionMap = std::unordered_map<uint64_t, std::pair<uint32_t, FiniteStateMachine::Action>>;
41     using EnterMap = std::unordered_map<uint32_t, FiniteStateMachine::Action>;
42     using LeaveMap = std::unordered_map<uint32_t, FiniteStateMachine::Action>;
43 
44     FiniteStateMachineImpl(std::string name, uint32_t initialState, TransitionMap &transitionMap, EnterMap &enterMap,
45         LeaveMap &leaveMap);
46     ~FiniteStateMachineImpl() override;
47 
48     void Schedule(uint32_t event) override;
49     uint32_t GetCurrentState() const override;
50     uint32_t EnsureCurrentState() override;
51     void SetThreadHandler(const std::shared_ptr<ThreadHandler> &threadHandler) override;
52     const std::string &GetMachineName() const override;
53     friend class FiniteStateMachineBuilder;
54 
55 private:
56     static constexpr uint32_t MAX_SCHEDULE_TIMES = 100;
GetTransitionIndex(uint32_t state,uint32_t event)57     constexpr static inline uint64_t GetTransitionIndex(uint32_t state, uint32_t event)
58     {
59         constexpr uint32_t uint32WidthLen = 32;
60         return (static_cast<uint64_t>(state) << uint32WidthLen) | event;
61     }
62     void ScheduleInner(FiniteStateMachine &machine);
63     void DealWithStateLeaveAndEnter(FiniteStateMachine &machine, uint32_t oldState, uint32_t newState);
64 
65     const std::string name_;
66     uint32_t currentState_;
67     std::shared_ptr<ThreadHandler> threadHandler_;
68     TransitionMap transitionMap_;
69     FiniteStateMachineImpl::EnterMap enterMap_;
70     FiniteStateMachineImpl::LeaveMap leaveMap_;
71 
72     std::mutex mutex_;
73     SafeQueue<uint32_t> pendingEvents_ {};
74 };
75 
76 class FiniteStateMachineImpl::Inner final : public FiniteStateMachine, public NoCopyable {
77 public:
78     explicit Inner(std::shared_ptr<FiniteStateMachineImpl> &machine);
79     ~Inner() override = default;
80     void Schedule(uint32_t event) override;
81     uint32_t GetCurrentState() const override;
82     uint32_t EnsureCurrentState() override;
83     const std::string &GetMachineName() const override;
84     void SetThreadHandler(const std::shared_ptr<ThreadHandler> &threadHandler) override;
85 
86 private:
87     std::shared_ptr<FiniteStateMachineImpl> &machine_;
88 };
89 } // namespace FaceAuth
90 } // namespace UserIam
91 } // namespace OHOS
92 
93 #endif // IAM_FINITE_STATE_MACHINE_IMPL_H