| /* |
| * |
| * Copyright (c) 2020 Project CHIP Authors |
| * All rights reserved. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| /** |
| * @file |
| * This file defines read handler for a CHIP Interaction Data model |
| * |
| */ |
| |
| #pragma once |
| |
| #include <access/AccessControl.h> |
| #include <app/AttributePathExpandIterator.h> |
| #include <app/AttributePathParams.h> |
| #include <app/AttributeValueEncoder.h> |
| #include <app/CASESessionManager.h> |
| #include <app/DataVersionFilter.h> |
| #include <app/EventManagement.h> |
| #include <app/EventPathParams.h> |
| #include <app/MessageDef/AttributePathIBs.h> |
| #include <app/MessageDef/DataVersionFilterIBs.h> |
| #include <app/MessageDef/EventFilterIBs.h> |
| #include <app/MessageDef/EventPathIBs.h> |
| #include <app/OperationalSessionSetup.h> |
| #include <app/SubscriptionResumptionSessionEstablisher.h> |
| #include <app/SubscriptionResumptionStorage.h> |
| #include <lib/core/CHIPCallback.h> |
| #include <lib/core/CHIPCore.h> |
| #include <lib/core/TLVDebug.h> |
| #include <lib/support/CodeUtils.h> |
| #include <lib/support/DLLUtil.h> |
| #include <lib/support/LinkedList.h> |
| #include <lib/support/logging/CHIPLogging.h> |
| #include <messaging/ExchangeHolder.h> |
| #include <messaging/ExchangeMgr.h> |
| #include <messaging/Flags.h> |
| #include <protocols/Protocols.h> |
| #include <system/SystemPacketBuffer.h> |
| |
| // https://github.com/CHIP-Specifications/connectedhomeip-spec/blob/61a9d19e6af12fdfb0872bcff26d19de6c680a1a/src/Ch02_Architecture.adoc#1122-subscribe-interaction-limits |
| inline constexpr uint16_t kSubscriptionMaxIntervalPublisherLimit = 3600; // seconds (60 minutes) |
| |
| namespace chip { |
| namespace app { |
| |
| // |
| // Forward declare the Engine (which is in a different namespace) to be able to use |
| // it as a friend class below. |
| // |
| namespace reporting { |
| class Engine; |
| class TestReportingEngine; |
| class ReportScheduler; |
| class TestReportScheduler; |
| } // namespace reporting |
| |
| class InteractionModelEngine; |
| class TestInteractionModelEngine; |
| |
| /** |
| * @class ReadHandler |
| * |
| * @brief The read handler is responsible for processing a read request, asking the attribute/event store |
| * for the relevant data, and sending a reply. |
| * |
| */ |
| class ReadHandler : public Messaging::ExchangeDelegate |
| { |
| public: |
| using SubjectDescriptor = Access::SubjectDescriptor; |
| |
| enum class InteractionType : uint8_t |
| { |
| Read, |
| Subscribe, |
| }; |
| |
| /* |
| * A callback used to interact with the application. |
| */ |
| class ApplicationCallback |
| { |
| public: |
| virtual ~ApplicationCallback() = default; |
| |
| /* |
| * Called right after a SubscribeRequest has been parsed and processed. This notifies an interested application |
| * of a subscription that is about to be established. It also provides an avenue for altering the parameters of the |
| * subscription (specifically, the min/max negotiated intervals) or even outright rejecting the subscription for |
| * application-specific reasons. |
| * |
| * TODO: Need a new IM status code to convey application-rejected subscribes. Currently, a Failure IM status code is sent |
| * back to the subscriber, which isn't sufficient. |
| * |
| * To reject the subscription, a CHIP_ERROR code that is not equivalent to CHIP_NO_ERROR should be returned. |
| * |
| * More information about the set of paths associated with this subscription can be retrieved by calling the appropriate |
| * Get* methods below. |
| * |
| * aReadHandler: Reference to the ReadHandler associated with the subscription. |
| * aSecureSession: A reference to the underlying secure session associated with the subscription. |
| * |
| */ |
| virtual CHIP_ERROR OnSubscriptionRequested(ReadHandler & aReadHandler, Transport::SecureSession & aSecureSession) |
| { |
| return CHIP_NO_ERROR; |
| } |
| |
| /* |
| * Called after a subscription has been fully established. |
| */ |
| virtual void OnSubscriptionEstablished(ReadHandler & aReadHandler){}; |
| |
| /* |
| * Called right before a subscription is about to get terminated. This is only called on subscriptions that were terminated |
| * after they had been fully established (and therefore had called OnSubscriptionEstablished). |
| * OnSubscriptionEstablishment(). |
| */ |
| virtual void OnSubscriptionTerminated(ReadHandler & aReadHandler){}; |
| }; |
| |
| /* |
| * A callback used to manage the lifetime of the ReadHandler object. |
| */ |
| class ManagementCallback |
| { |
| public: |
| virtual ~ManagementCallback() = default; |
| |
| /* |
| * Method that signals to a registered callback that this object |
| * has completed doing useful work and is now safe for release/destruction. |
| */ |
| virtual void OnDone(ReadHandler & apReadHandlerObj) = 0; |
| |
| /* |
| * Retrieve the ApplicationCallback (if a valid one exists) from our management entity. This avoids |
| * storing multiple references to the application provided callback and having to subsequently manage lifetime |
| * issues w.r.t the ReadHandler itself. |
| */ |
| virtual ApplicationCallback * GetAppCallback() = 0; |
| |
| /* |
| * Retrieve the InteractionalModelEngine that holds this ReadHandler. |
| */ |
| virtual InteractionModelEngine * GetInteractionModelEngine() = 0; |
| }; |
| |
| // TODO (#27675) : Merge existing callback and observer into one class and have an observer pool in the Readhandler to notify |
| // every |
| /* |
| * Observer class for ReadHandler, meant to allow multiple objects to observe the ReadHandler. Currently only one observer is |
| * supported but all above callbacks should be merged into observer type and an observer pool should be added to allow multiple |
| * objects to observe ReadHandler |
| */ |
| class Observer |
| { |
| public: |
| virtual ~Observer() = default; |
| |
| /// @brief Callback invoked to notify a subscription was successfully established for the ReadHandler |
| /// @param[in] apReadHandler ReadHandler that completed its subscription |
| virtual void OnSubscriptionEstablished(ReadHandler * apReadHandler) = 0; |
| |
| /// @brief Callback invoked when a ReadHandler went from a non reportable state to a reportable state. Indicates to the |
| /// observer that a report should be emitted when the min interval allows it. |
| /// |
| /// This will only be invoked for subscribe-type ReadHandler objects, and only after |
| /// OnSubscriptionEstablished has been called. |
| /// |
| /// @param[in] apReadHandler ReadHandler that became dirty and in HandlerState::CanStartReporting state |
| virtual void OnBecameReportable(ReadHandler * apReadHandler) = 0; |
| |
| /// @brief Callback invoked when the read handler needs to make sure to send a message to the subscriber within the next |
| /// maxInterval time period. |
| /// @param[in] apReadHandler ReadHandler that has generated a report |
| virtual void OnSubscriptionReportSent(ReadHandler * apReadHandler) = 0; |
| |
| /// @brief Callback invoked when a ReadHandler is getting removed so it can be unregistered |
| /// @param[in] apReadHandler ReadHandler getting destroyed |
| virtual void OnReadHandlerDestroyed(ReadHandler * apReadHandler) = 0; |
| }; |
| |
| /* |
| * Destructor - as part of destruction, it will abort the exchange context |
| * if a valid one still exists. |
| * |
| * See Abort() for details on when that might occur. |
| */ |
| ~ReadHandler() override; |
| |
| /** |
| * |
| * Constructor. |
| * |
| * The callback passed in has to outlive this handler object. |
| * |
| */ |
| ReadHandler(ManagementCallback & apCallback, Messaging::ExchangeContext * apExchangeContext, InteractionType aInteractionType, |
| Observer * observer); |
| |
| #if CHIP_CONFIG_PERSIST_SUBSCRIPTIONS |
| /** |
| * |
| * Constructor in preparation for resuming a persisted subscription |
| * |
| * The callback passed in has to outlive this handler object. |
| * |
| */ |
| ReadHandler(ManagementCallback & apCallback, Observer * observer); |
| #endif |
| |
| const SingleLinkedListNode<AttributePathParams> * GetAttributePathList() const { return mpAttributePathList; } |
| const SingleLinkedListNode<EventPathParams> * GetEventPathList() const { return mpEventPathList; } |
| const SingleLinkedListNode<DataVersionFilter> * GetDataVersionFilterList() const { return mpDataVersionFilterList; } |
| |
| void GetReportingIntervals(uint16_t & aMinInterval, uint16_t & aMaxInterval) const |
| { |
| aMinInterval = mMinIntervalFloorSeconds; |
| aMaxInterval = mMaxInterval; |
| } |
| |
| CHIP_ERROR SetMinReportingIntervalForTests(uint16_t aMinInterval) |
| { |
| VerifyOrReturnError(IsIdle(), CHIP_ERROR_INCORRECT_STATE); |
| VerifyOrReturnError(aMinInterval <= mMaxInterval, CHIP_ERROR_INVALID_ARGUMENT); |
| // Ensures the new min interval is higher than the subscriber established one. |
| mMinIntervalFloorSeconds = std::max(mMinIntervalFloorSeconds, aMinInterval); |
| return CHIP_NO_ERROR; |
| } |
| |
| /* |
| * Set the maximum reporting interval for the subscription. This SHALL only be called |
| * from the OnSubscriptionRequested callback above. The restriction is as below |
| * MinIntervalFloor ≤ MaxInterval ≤ MAX(SUBSCRIPTION_MAX_INTERVAL_PUBLISHER_LIMIT, MaxIntervalCeiling) |
| * Where SUBSCRIPTION_MAX_INTERVAL_PUBLISHER_LIMIT is set to 60m in the spec. |
| */ |
| CHIP_ERROR SetMaxReportingInterval(uint16_t aMaxInterval) |
| { |
| VerifyOrReturnError(IsIdle(), CHIP_ERROR_INCORRECT_STATE); |
| VerifyOrReturnError(mMinIntervalFloorSeconds <= aMaxInterval, CHIP_ERROR_INVALID_ARGUMENT); |
| VerifyOrReturnError(aMaxInterval <= std::max(GetPublisherSelectedIntervalLimit(), mMaxInterval), |
| CHIP_ERROR_INVALID_ARGUMENT); |
| mMaxInterval = aMaxInterval; |
| return CHIP_NO_ERROR; |
| } |
| |
| #if CHIP_CONFIG_PERSIST_SUBSCRIPTIONS |
| /** |
| * |
| * @brief Initialize a ReadHandler for a resumed subsciption |
| * |
| * Used after the SubscriptionResumptionSessionEstablisher establishs the CASE session |
| */ |
| void OnSubscriptionResumed(const SessionHandle & sessionHandle, SubscriptionResumptionSessionEstablisher & sessionEstablisher); |
| #endif |
| |
| private: |
| PriorityLevel GetCurrentPriority() const { return mCurrentPriority; } |
| EventNumber & GetEventMin() { return mEventMin; } |
| |
| /** |
| * Returns SUBSCRIPTION_MAX_INTERVAL_PUBLISHER_LIMIT |
| * For an ICD publisher, this SHALL be set to the idle mode duration. |
| * Otherwise, this SHALL be set to 60 minutes. |
| */ |
| uint16_t GetPublisherSelectedIntervalLimit(); |
| |
| enum class ReadHandlerFlags : uint8_t |
| { |
| // The flag indicating we are in the middle of a series of chunked report messages, this flag will be cleared during |
| // sending last chunked message. |
| ChunkedReport = (1 << 0), |
| |
| // Tracks whether we're in the initial phase of receiving priming |
| // reports, which is always true for reads and true for subscriptions |
| // prior to receiving a subscribe response. |
| PrimingReports = (1 << 1), |
| ActiveSubscription = (1 << 2), |
| FabricFiltered = (1 << 3), |
| // For subscriptions, we record the dirty set generation when we started to generate the last report. |
| // The mCurrentReportsBeginGeneration records the generation at the start of the current report. This only/ |
| // has a meaningful value while IsReporting() is true. |
| // |
| // mPreviousReportsBeginGeneration will be set to mCurrentReportsBeginGeneration after we send the last |
| // chunk of the current report. Anything that was dirty with a generation earlier than |
| // mPreviousReportsBeginGeneration has had its value sent to the client. |
| // when receiving initial request, it needs mark current handler as dirty. |
| // when there is urgent event, it needs mark current handler as dirty. |
| ForceDirty = (1 << 4), |
| |
| // Don't need the response for report data if true |
| SuppressResponse = (1 << 5), |
| }; |
| |
| /** |
| * Process a read/subscribe request. Parts of the processing may end up being asynchronous, but the ReadHandler |
| * guarantees that it will call Shutdown on itself when processing is done (including if OnReadInitialRequest |
| * returns an error). |
| * |
| * @retval #Others If fails to process read request |
| * @retval #CHIP_NO_ERROR On success. |
| * |
| */ |
| void OnInitialRequest(System::PacketBufferHandle && aPayload); |
| |
| /** |
| * Send ReportData to initiator |
| * |
| * @param[in] aPayload A payload that has read request data |
| * @param[in] aMoreChunks A flags indicating there will be more chunks expected to be sent for this read request |
| * |
| * @retval #Others If fails to send report data |
| * @retval #CHIP_NO_ERROR On success. |
| * |
| * If an error is returned, the ReadHandler guarantees that it is not in |
| * a state where it's waiting for a response. |
| */ |
| CHIP_ERROR SendReportData(System::PacketBufferHandle && aPayload, bool aMoreChunks); |
| |
| /** |
| * Returns whether this ReadHandler represents a subscription that was created by the other side of the provided exchange. |
| */ |
| bool IsFromSubscriber(Messaging::ExchangeContext & apExchangeContext) const; |
| |
| bool IsIdle() const { return mState == HandlerState::Idle; } |
| |
| /// @brief Returns whether the ReadHandler is in a state where it can send a report and there is data to report. |
| bool ShouldStartReporting() const |
| { |
| // Important: Anything that changes ShouldStartReporting() from false to true |
| // (which can only happen for subscriptions) must call |
| // mObserver->OnBecameReportable(this). |
| return CanStartReporting() && (ShouldReportUnscheduled() || IsDirty()); |
| } |
| /// @brief CanStartReporting() is true if the ReadHandler is in a state where it could generate |
| /// a (possibly empty) report if someone asked it to. |
| bool CanStartReporting() const { return mState == HandlerState::CanStartReporting; } |
| /// @brief ShouldReportUnscheduled() is true if the ReadHandler should be asked to generate reports |
| /// without consulting the report scheduler. |
| bool ShouldReportUnscheduled() const |
| { |
| return CanStartReporting() && (IsType(ReadHandler::InteractionType::Read) || IsPriming()); |
| } |
| bool IsAwaitingReportResponse() const { return mState == HandlerState::AwaitingReportResponse; } |
| |
| // Resets the path iterator to the beginning of the whole report for generating a series of new reports. |
| void ResetPathIterator(); |
| |
| CHIP_ERROR ProcessDataVersionFilterList(DataVersionFilterIBs::Parser & aDataVersionFilterListParser); |
| |
| // if current priority is in the middle, it has valid snapshoted last event number, it check cleaness via comparing |
| // with snapshotted last event number. if current priority is in the end, no valid |
| // sanpshotted last event, check with latest last event number, re-setup snapshoted checkpoint, and compare again. |
| bool CheckEventClean(EventManagement & aEventManager); |
| |
| bool IsType(InteractionType type) const { return (mInteractionType == type); } |
| bool IsChunkedReport() const { return mFlags.Has(ReadHandlerFlags::ChunkedReport); } |
| // Is reporting indicates whether we are in the middle of a series chunks. As we will set mIsChunkedReport on the first chunk |
| // and clear that flag on the last chunk, we can use mIsChunkedReport to indicate this state. |
| bool IsReporting() const { return mFlags.Has(ReadHandlerFlags::ChunkedReport); } |
| bool IsPriming() const { return mFlags.Has(ReadHandlerFlags::PrimingReports); } |
| bool IsActiveSubscription() const { return mFlags.Has(ReadHandlerFlags::ActiveSubscription); } |
| bool IsFabricFiltered() const { return mFlags.Has(ReadHandlerFlags::FabricFiltered); } |
| CHIP_ERROR OnSubscribeRequest(Messaging::ExchangeContext * apExchangeContext, System::PacketBufferHandle && aPayload); |
| void GetSubscriptionId(SubscriptionId & aSubscriptionId) const { aSubscriptionId = mSubscriptionId; } |
| AttributePathExpandIterator * GetAttributePathExpandIterator() { return &mAttributePathExpandIterator; } |
| |
| /// @brief Notifies the read handler that a set of attribute paths has been marked dirty. This will schedule a reporting engine |
| /// run if the change to the attribute path makes the ReadHandler reportable. |
| /// @param aAttributeChanged Path to the attribute that was changed. |
| void AttributePathIsDirty(const AttributePathParams & aAttributeChanged); |
| bool IsDirty() const |
| { |
| return (mDirtyGeneration > mPreviousReportsBeginGeneration) || mFlags.Has(ReadHandlerFlags::ForceDirty); |
| } |
| void ClearForceDirtyFlag() { ClearStateFlag(ReadHandlerFlags::ForceDirty); } |
| NodeId GetInitiatorNodeId() const |
| { |
| auto session = GetSession(); |
| return session == nullptr ? kUndefinedNodeId : session->GetPeerNodeId(); |
| } |
| |
| FabricIndex GetAccessingFabricIndex() const |
| { |
| auto session = GetSession(); |
| return session == nullptr ? kUndefinedFabricIndex : session->GetFabricIndex(); |
| } |
| |
| Transport::SecureSession * GetSession() const; |
| SubjectDescriptor GetSubjectDescriptor() const { return GetSession()->GetSubjectDescriptor(); } |
| |
| auto GetTransactionStartGeneration() const { return mTransactionStartGeneration; } |
| |
| /// @brief Forces the read handler into a dirty state, regardless of what's going on with attributes. |
| /// This can lead to scheduling of a reporting run immediately, if the min interval has been reached, |
| /// or after the min interval is reached if it has not yet been reached. |
| void ForceDirtyState(); |
| |
| const AttributeValueEncoder::AttributeEncodeState & GetAttributeEncodeState() const { return mAttributeEncoderState; } |
| void SetAttributeEncodeState(const AttributeValueEncoder::AttributeEncodeState & aState) { mAttributeEncoderState = aState; } |
| uint32_t GetLastWrittenEventsBytes() const { return mLastWrittenEventsBytes; } |
| |
| // Returns the number of interested paths, including wildcard and concrete paths. |
| size_t GetAttributePathCount() const { return mpAttributePathList == nullptr ? 0 : mpAttributePathList->Count(); }; |
| size_t GetEventPathCount() const { return mpEventPathList == nullptr ? 0 : mpEventPathList->Count(); }; |
| size_t GetDataVersionFilterCount() const { return mpDataVersionFilterList == nullptr ? 0 : mpDataVersionFilterList->Count(); }; |
| |
| CHIP_ERROR SendStatusReport(Protocols::InteractionModel::Status aStatus); |
| |
| friend class TestReadInteraction; |
| friend class chip::app::reporting::TestReportingEngine; |
| friend class chip::app::reporting::TestReportScheduler; |
| |
| // |
| // The engine needs to be able to Abort/Close a ReadHandler instance upon completion of work for a given read/subscribe |
| // interaction. We do not want to make these methods public just to give an adjacent class in the IM access, since public |
| // should really be taking application usage considerations as well. Hence, make it a friend. |
| // |
| friend class chip::app::reporting::Engine; |
| friend class chip::app::InteractionModelEngine; |
| friend class TestInteractionModelEngine; |
| |
| // The report scheduler needs to be able to access StateFlag private functions ShouldStartReporting(), CanStartReporting(), |
| // ForceDirtyState() and IsDirty() to know when to schedule a run so it is declared as a friend class. |
| friend class chip::app::reporting::ReportScheduler; |
| |
| enum class HandlerState : uint8_t |
| { |
| Idle, ///< The handler has been initialized and is ready |
| CanStartReporting, ///< The handler has is now capable of generating reports and may generate one immediately |
| ///< or later when other criteria are satisfied (e.g hold-off for min reporting interval). |
| AwaitingReportResponse, ///< The handler has sent the report to the client and is awaiting a status response. |
| AwaitingDestruction, ///< The object has completed its work and is awaiting destruction by the application. |
| }; |
| |
| enum class CloseOptions |
| { |
| kDropPersistedSubscription, |
| kKeepPersistedSubscription |
| }; |
| /** |
| * Called internally to signal the completion of all work on this objecta and signal to a registered callback that it's |
| * safe to release this object. |
| * |
| * @param options This specifies whether to drop or keep the subscription |
| * |
| */ |
| void Close(CloseOptions options = CloseOptions::kDropPersistedSubscription); |
| |
| CHIP_ERROR SendSubscribeResponse(); |
| CHIP_ERROR ProcessSubscribeRequest(System::PacketBufferHandle && aPayload); |
| CHIP_ERROR ProcessReadRequest(System::PacketBufferHandle && aPayload); |
| CHIP_ERROR ProcessAttributePaths(AttributePathIBs::Parser & aAttributePathListParser); |
| CHIP_ERROR ProcessEventPaths(EventPathIBs::Parser & aEventPathsParser); |
| CHIP_ERROR ProcessEventFilters(EventFilterIBs::Parser & aEventFiltersParser); |
| CHIP_ERROR OnStatusResponse(Messaging::ExchangeContext * apExchangeContext, System::PacketBufferHandle && aPayload, |
| bool & aSendStatusResponse); |
| CHIP_ERROR OnMessageReceived(Messaging::ExchangeContext * apExchangeContext, const PayloadHeader & aPayloadHeader, |
| System::PacketBufferHandle && aPayload) override; |
| void OnResponseTimeout(Messaging::ExchangeContext * apExchangeContext) override; |
| void MoveToState(const HandlerState aTargetState); |
| |
| const char * GetStateStr() const; |
| |
| void PersistSubscription(); |
| |
| /// @brief Modifies a state flag in the read handler. If the read handler went from a |
| /// non-reportable state to a reportable state, schedules a reporting engine run. |
| /// @param aFlag Flag to set |
| /// @param aValue Flag new value |
| void SetStateFlag(ReadHandlerFlags aFlag, bool aValue = true); |
| |
| /// @brief This function call SetStateFlag with the flag value set to false, thus possibly emitting a report |
| /// generation. |
| /// @param aFlag Flag to clear |
| void ClearStateFlag(ReadHandlerFlags aFlag); |
| |
| AttributePathExpandIterator mAttributePathExpandIterator = AttributePathExpandIterator(nullptr); |
| |
| // The current generation of the reporting engine dirty set the last time we were notified that a path we're interested in was |
| // marked dirty. |
| // |
| // This allows us to detemine whether any paths we care about might have |
| // been marked dirty after we had already sent reports for them, which would |
| // mean we should report those paths again, by comparing this generation to the |
| // current generation when we started sending the last set reports that we completed. |
| // |
| // This allows us to reset the iterator to the beginning of the current |
| // cluster instead of the beginning of the whole report in AttributePathIsDirty, without |
| // permanently missing dirty any paths. |
| uint64_t mDirtyGeneration = 0; |
| |
| // For subscriptions, we record the timestamp when we started to generate the last report. |
| // The mCurrentReportsBeginGeneration records the timestamp for the current report, which won;t be used for checking if this |
| // ReadHandler is dirty. |
| // mPreviousReportsBeginGeneration will be set to mCurrentReportsBeginGeneration after we sent the last chunk of the current |
| // report. |
| uint64_t mPreviousReportsBeginGeneration = 0; |
| uint64_t mCurrentReportsBeginGeneration = 0; |
| /* |
| * (mDirtyGeneration = b > a, this is a dirty read handler) |
| * +- Start Report -> mCurrentReportsBeginGeneration = c |
| * | +- AttributePathIsDirty (Attribute Y) -> mDirtyGeneration = d |
| * | | +- Last Chunk -> mPreviousReportsBeginGeneration = mCurrentReportsBeginGeneration = c |
| * | | | +- (mDirtyGeneration = d) > (mPreviousReportsBeginGeneration = c), this is a dirty read handler |
| * | | | | Attribute X has a dirty generation less than c, Attribute Y has a dirty generation larger than c |
| * | | | | So Y will be included in the report but X will not be inclued in this report. |
| * -a--b--c------d-----e---f---> Generation |
| * | | |
| * | +- AttributePathIsDirty (Attribute X) (mDirtyGeneration = b) |
| * +- mPreviousReportsBeginGeneration |
| * For read handler, if mDirtyGeneration > mPreviousReportsBeginGeneration, then we regard it as a dirty read handler, and it |
| * should generate report on timeout reached. |
| */ |
| |
| // When we don't have enough resources for a new subscription, the oldest subscription might be evicted by interaction model |
| // engine, the "oldest" subscription is the subscription with the smallest generation. |
| uint64_t mTransactionStartGeneration = 0; |
| |
| SubscriptionId mSubscriptionId = 0; |
| uint16_t mMinIntervalFloorSeconds = 0; |
| uint16_t mMaxInterval = 0; |
| |
| EventNumber mEventMin = 0; |
| |
| // The last schedule event number snapshoted in the beginning when preparing to fill new events to reports |
| EventNumber mLastScheduledEventNumber = 0; |
| |
| // TODO: We should shutdown the transaction when the session expires. |
| SessionHolder mSessionHandle; |
| |
| Messaging::ExchangeHolder mExchangeCtx; |
| #if CHIP_CONFIG_UNSAFE_SUBSCRIPTION_EXCHANGE_MANAGER_USE |
| // TODO: this should be replaced by a pointer to the InteractionModelEngine that created the ReadHandler |
| // once InteractionModelEngine is no longer a singleton (see issue 23625) |
| Messaging::ExchangeManager * mExchangeMgr = nullptr; |
| #endif // CHIP_CONFIG_UNSAFE_SUBSCRIPTION_EXCHANGE_MANAGER_USE |
| |
| SingleLinkedListNode<AttributePathParams> * mpAttributePathList = nullptr; |
| SingleLinkedListNode<EventPathParams> * mpEventPathList = nullptr; |
| SingleLinkedListNode<DataVersionFilter> * mpDataVersionFilterList = nullptr; |
| |
| ManagementCallback & mManagementCallback; |
| |
| uint32_t mLastWrittenEventsBytes = 0; |
| |
| // The detailed encoding state for a single attribute, used by list chunking feature. |
| // The size of AttributeEncoderState is 2 bytes for now. |
| AttributeValueEncoder::AttributeEncodeState mAttributeEncoderState; |
| |
| // Current Handler state |
| HandlerState mState = HandlerState::Idle; |
| PriorityLevel mCurrentPriority = PriorityLevel::Invalid; |
| BitFlags<ReadHandlerFlags> mFlags; |
| InteractionType mInteractionType = InteractionType::Read; |
| |
| // TODO (#27675): Merge all observers into one and that one will dispatch the callbacks to the right place. |
| Observer * mObserver = nullptr; |
| }; |
| } // namespace app |
| } // namespace chip |
