| /* |
| * |
| * Copyright (c) 2021 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 client for a CHIP Interaction Data model |
| * |
| */ |
| |
| #pragma once |
| #include "system/SystemClock.h" |
| #include <app/AttributePathParams.h> |
| #include <app/ConcreteAttributePath.h> |
| #include <app/EventHeader.h> |
| #include <app/EventPathParams.h> |
| #include <app/MessageDef/ReadRequestMessage.h> |
| #include <app/MessageDef/StatusIB.h> |
| #include <app/MessageDef/StatusResponseMessage.h> |
| #include <app/MessageDef/SubscribeRequestMessage.h> |
| #include <app/MessageDef/SubscribeResponseMessage.h> |
| #include <app/OperationalSessionSetup.h> |
| #include <app/ReadPrepareParams.h> |
| #include <app/data-model/Decode.h> |
| #include <lib/core/CHIPCallback.h> |
| #include <lib/core/CHIPCore.h> |
| #include <lib/core/CHIPTLVDebug.hpp> |
| #include <lib/support/CodeUtils.h> |
| #include <lib/support/DLLUtil.h> |
| #include <lib/support/logging/CHIPLogging.h> |
| #include <messaging/ExchangeContext.h> |
| #include <messaging/ExchangeHolder.h> |
| #include <messaging/ExchangeMgr.h> |
| #include <messaging/Flags.h> |
| #include <protocols/Protocols.h> |
| #include <system/SystemPacketBuffer.h> |
| |
| namespace chip { |
| namespace app { |
| |
| class InteractionModelEngine; |
| |
| /** |
| * @class ReadClient |
| * |
| * @brief The read client represents the initiator side of a Read Or Subscribe Interaction (depending on the APIs invoked). |
| * |
| * When used to manage subscriptions, the client provides functionality to automatically re-subscribe as needed, |
| * including re-establishing CASE under certain conditions (see Callback::OnResubscriptionNeeded for more info). |
| * This is the default behavior. A consumer can completely opt-out of this behavior by over-riding |
| * Callback::OnResubscriptionNeeded and providing an alternative implementation. |
| * |
| */ |
| class ReadClient : public Messaging::ExchangeDelegate |
| { |
| public: |
| class Callback |
| { |
| public: |
| virtual ~Callback() = default; |
| |
| /** |
| * Used to signal the commencement of processing of the first attribute or event report received in a given exchange. |
| * |
| * This object MUST continue to exist after this call is completed. The application shall wait until it |
| * receives an OnDone call to destroy the object. |
| * |
| * Once OnReportBegin has been called, either OnReportEnd or OnError will be called before OnDone. |
| * |
| */ |
| virtual void OnReportBegin() {} |
| |
| /** |
| * Used to signal the completion of processing of the last attribute or event report in a given exchange. |
| * |
| * This object MUST continue to exist after this call is completed. The application shall wait until it |
| * receives an OnDone call to destroy the object. |
| * |
| */ |
| virtual void OnReportEnd() {} |
| |
| /** |
| * Used to deliver event data received through the Read and Subscribe interactions |
| * |
| * Only one of the apData and apStatus can be non-null. |
| * |
| * This object MUST continue to exist after this call is completed. The application shall wait until it |
| * receives an OnDone call to destroy the object. |
| * |
| * @param[in] aEventHeader The event header in report response. |
| * @param[in] apData A TLVReader positioned right on the payload of the event. |
| * @param[in] apStatus Event-specific status, containing an InteractionModel::Status code as well as an optional |
| * cluster-specific status code. |
| */ |
| virtual void OnEventData(const EventHeader & aEventHeader, TLV::TLVReader * apData, const StatusIB * apStatus) {} |
| |
| /** |
| * Used to deliver attribute data received through the Read and Subscribe interactions. |
| * |
| * This callback will be called when: |
| * - Receiving attribute data as response of Read interactions |
| * - Receiving attribute data as reports of subscriptions |
| * - Receiving attribute data as initial reports of subscriptions |
| * |
| * This object MUST continue to exist after this call is completed. The application shall wait until it |
| * receives an OnDone call to destroy the object. |
| * |
| * @param[in] aPath The attribute path field in report response. |
| * @param[in] apData The attribute data of the given path, will be a nullptr if status is not Success. |
| * @param[in] aStatus Attribute-specific status, containing an InteractionModel::Status code as well as an |
| * optional cluster-specific status code. |
| */ |
| virtual void OnAttributeData(const ConcreteDataAttributePath & aPath, TLV::TLVReader * apData, const StatusIB & aStatus) {} |
| |
| /** |
| * OnSubscriptionEstablished will be called when a subscription is established for the given subscription transaction. |
| * If using auto resubscription, OnSubscriptionEstablished will be called whenever resubscription is established. |
| * |
| * This object MUST continue to exist after this call is completed. The application shall wait until it |
| * receives an OnDone call to destroy the object. |
| * |
| * @param[in] aSubscriptionId The identifier of the subscription that was established. |
| */ |
| virtual void OnSubscriptionEstablished(SubscriptionId aSubscriptionId) {} |
| |
| /** |
| * OnResubscriptionNeeded will be called when a subscription that was started with SendAutoResubscribeRequest has terminated |
| * and re-subscription is needed. The termination cause is provided to help inform subsequent re-subscription logic. |
| * |
| * The base implementation automatically re-subscribes at appropriate intervals taking the termination cause into account |
| * (see ReadClient::DefaultResubscribePolicy for more details). If the default implementation doesn't suffice, the logic of |
| * ReadClient::DefaultResubscribePolicy is broken down into its constituent methods that are publicly available for |
| * applications to call and sequence. |
| * |
| * If the method is over-ridden, it's the application's responsibility to take the appropriate steps needed to eventually |
| * call-back into the ReadClient object to schedule a re-subscription (by invoking ReadClient::ScheduleResubscription). |
| * |
| * If the application DOES NOT want re-subscription to happen on a particular invocation of this method, returning anything |
| * other than CHIP_NO_ERROR will terminate the interaction and result in OnError, OnDeallocatePaths and OnDone being called |
| * in that sequence. |
| * |
| * This object MUST continue to exist after this call is completed. The |
| * application shall wait until it receives an OnDone call to destroy the object. |
| * |
| * @param[in] aTerminationCause The cause of failure of the subscription that just terminated. |
| */ |
| virtual CHIP_ERROR OnResubscriptionNeeded(ReadClient * apReadClient, CHIP_ERROR aTerminationCause) |
| { |
| return apReadClient->DefaultResubscribePolicy(aTerminationCause); |
| } |
| |
| /** |
| * OnError will be called when an error occurs *after* a successful call to SendRequest(). The following |
| * errors will be delivered through this call in the aError field: |
| * |
| * - CHIP_ERROR_TIMEOUT: A response was not received within the expected response timeout. |
| * - CHIP_ERROR_*TLV*: A malformed, non-compliant response was received from the server. |
| * - CHIP_ERROR encapsulating a StatusIB: If we got a non-path-specific |
| * status response from the server. In that case, |
| * StatusIB::InitFromChipError can be used to extract the status. |
| * - CHIP_ERROR*: All other cases. |
| * |
| * This object MUST continue to exist after this call is completed. The application shall wait until it |
| * receives an OnDone call to destroy the object. |
| * |
| * @param[in] aError A system error code that conveys the overall error code. |
| */ |
| virtual void OnError(CHIP_ERROR aError) {} |
| |
| /** |
| * OnDone will be called when ReadClient has finished all work and it is |
| * safe to destroy and free the allocated ReadClient object and any |
| * other objects associated with the Read or Subscribe interaction. |
| * |
| * This function will: |
| * - Always be called exactly *once* for a given ReadClient instance. |
| * - Be called even in error circumstances. |
| * - Only be called after a successful call to SendRequest has been |
| * made, when the read completes or the subscription is shut down. |
| * |
| * @param[in] apReadClient the ReadClient for the completed interaction. |
| */ |
| virtual void OnDone(ReadClient * apReadClient) = 0; |
| |
| /** |
| * This function is invoked when using SendAutoResubscribeRequest, where the ReadClient was configured to auto re-subscribe |
| * and the ReadPrepareParams was moved into this client for management. This will have to be free'ed appropriately by the |
| * application. If SendAutoResubscribeRequest fails, this function will be called before it returns the failure. If |
| * SendAutoResubscribeRequest succeeds, this function will be called immediately before calling OnDone, or |
| * when the ReadClient is destroyed, if that happens before OnDone. If SendAutoResubscribeRequest is not called, |
| * this function will not be called. |
| */ |
| virtual void OnDeallocatePaths(ReadPrepareParams && aReadPrepareParams) {} |
| |
| /** |
| * This function is invoked when constructing a read/subscribeRequest that does not have data |
| * version filters specified, to give the callback a chance to provide some. |
| * |
| * This function is expected to encode as many complete data version filters as will fit into |
| * the buffer, rolling back any partially-encoded filters if it runs out of space, and set the |
| * aEncodedDataVersionList boolean to true if it has successfully encoded at least one data version filter. |
| * |
| * Otherwise aEncodedDataVersionList will be set to false. |
| */ |
| virtual CHIP_ERROR OnUpdateDataVersionFilterList(DataVersionFilterIBs::Builder & aDataVersionFilterIBsBuilder, |
| const Span<AttributePathParams> & aAttributePaths, |
| bool & aEncodedDataVersionList) |
| { |
| aEncodedDataVersionList = false; |
| return CHIP_NO_ERROR; |
| } |
| |
| /* |
| * Get highest received event number. |
| * If the application does not want to filter events by event number, it should call ClearValue() on aEventNumber |
| * and return CHIP_NO_ERROR. An error return from this function will fail the entire read client interaction. |
| */ |
| virtual CHIP_ERROR GetHighestReceivedEventNumber(Optional<EventNumber> & aEventNumber) |
| { |
| aEventNumber.ClearValue(); |
| return CHIP_NO_ERROR; |
| } |
| }; |
| |
| enum class InteractionType : uint8_t |
| { |
| Read, |
| Subscribe, |
| }; |
| |
| /** |
| * |
| * Constructor. |
| * |
| * The callback passed in has to outlive this ReadClient object. |
| * |
| * This object can outlive the InteractionModelEngine passed in. However, upon shutdown of the engine, |
| * this object will cease to function correctly since it depends on the engine for a number of critical functions. |
| * |
| * @param[in] apImEngine A valid pointer to the IM engine. |
| * @param[in] apExchangeMgr A pointer to the ExchangeManager object. |
| * @param[in] apCallback Callback set by application. |
| * @param[in] aInteractionType Type of interaction (read or subscribe) |
| * |
| * @retval #CHIP_ERROR_INCORRECT_STATE incorrect state if it is already initialized |
| * @retval #CHIP_NO_ERROR On success. |
| * |
| */ |
| ReadClient(InteractionModelEngine * apImEngine, Messaging::ExchangeManager * apExchangeMgr, Callback & apCallback, |
| InteractionType aInteractionType); |
| |
| /** |
| * Destructor. |
| * |
| * Will abort the exchange context if a valid one still exists. It will also cancel any |
| * liveness timers that may be active. |
| * |
| * OnDone() will not be called. |
| */ |
| ~ReadClient() override; |
| |
| /** |
| * Send a request. There can be one request outstanding on a given ReadClient. |
| * If SendRequest returns success, no more SendRequest calls can happen on this ReadClient |
| * until the corresponding OnDone call has happened. |
| * |
| * This will send either a Read Request or a Subscribe Request depending on |
| * the InteractionType this read client was initialized with. |
| * |
| * @retval #others fail to send read request |
| * @retval #CHIP_NO_ERROR On success. |
| */ |
| CHIP_ERROR SendRequest(ReadPrepareParams & aReadPrepareParams); |
| |
| void OnUnsolicitedReportData(Messaging::ExchangeContext * apExchangeContext, System::PacketBufferHandle && aPayload); |
| |
| auto GetSubscriptionId() const |
| { |
| using returnType = Optional<decltype(mSubscriptionId)>; |
| return mInteractionType == InteractionType::Subscribe ? returnType(mSubscriptionId) : returnType::Missing(); |
| } |
| |
| FabricIndex GetFabricIndex() const { return mPeer.GetFabricIndex(); } |
| NodeId GetPeerNodeId() const { return mPeer.GetNodeId(); } |
| bool IsReadType() { return mInteractionType == InteractionType::Read; } |
| bool IsSubscriptionType() const { return mInteractionType == InteractionType::Subscribe; }; |
| |
| /* |
| * Retrieve the reporting intervals associated with an active subscription. This should only be called if we're of subscription |
| * interaction type and after a subscription has been established. |
| */ |
| CHIP_ERROR GetReportingIntervals(uint16_t & aMinIntervalFloorSeconds, uint16_t & aMaxIntervalCeilingSeconds) const |
| { |
| VerifyOrReturnError(IsSubscriptionType(), CHIP_ERROR_INCORRECT_STATE); |
| VerifyOrReturnError(IsSubscriptionActive(), CHIP_ERROR_INCORRECT_STATE); |
| |
| aMinIntervalFloorSeconds = mMinIntervalFloorSeconds; |
| aMaxIntervalCeilingSeconds = mMaxInterval; |
| |
| return CHIP_NO_ERROR; |
| } |
| |
| ReadClient * GetNextClient() { return mpNext; } |
| void SetNextClient(ReadClient * apClient) { mpNext = apClient; } |
| |
| /** |
| * Like SendSubscribeRequest, but the ReadClient will automatically attempt to re-establish the subscription if |
| * we decide that the subscription has dropped. The exact behavior of the re-establishment can be controlled |
| * by setting mResubscribePolicy in the ReadPrepareParams. If not set, a default behavior with exponential backoff will be |
| * used. |
| * |
| * The application has to know to |
| * a) allocate a ReadPrepareParams object that will have fields mpEventPathParamsList and mpAttributePathParamsList and |
| * mpDataVersionFilterList with lifetimes as long as the ReadClient itself and b) free those up later in the call to |
| * OnDeallocatePaths. Note: At a given time in the system, you can either have a single subscription with re-sub enabled that |
| * has mKeepSubscriptions = false, OR, multiple subs with re-sub enabled with mKeepSubscriptions = true. You shall not |
| * have a mix of both simultaneously. If SendAutoResubscribeRequest is called at all, it guarantees that it will call |
| * OnDeallocatePaths when OnDone is called. SendAutoResubscribeRequest is the only case that calls OnDeallocatePaths, since |
| * that's the only case when the consumer moved a ReadParams into the client. |
| * |
| */ |
| CHIP_ERROR SendAutoResubscribeRequest(ReadPrepareParams && aReadPrepareParams); |
| |
| /** |
| * This provides a standard re-subscription policy implementation that given a termination cause, does the following: |
| * - Calculates the time till next subscription with fibonacci back-off (implemented by ComputeTimeTillNextSubscription()). |
| * - Schedules the next subscription attempt at the computed interval from the previous step. Operational discovery and |
| * CASE establishment will be attempted if aTerminationCause was CHIP_ERROR_TIMEOUT. In all other cases, it will attempt |
| * to re-use a previously established session. |
| */ |
| CHIP_ERROR DefaultResubscribePolicy(CHIP_ERROR aTerminationCause); |
| |
| /** |
| * Computes the time, in milliseconds, until the next re-subscription over |
| * an ever increasing window following a fibonacci sequence with the current retry count |
| * used as input to the fibonacci algorithm. |
| * |
| * CHIP_RESUBSCRIBE_MAX_FIBONACCI_STEP_INDEX is the maximum value the retry count can tick up to. |
| * |
| */ |
| uint32_t ComputeTimeTillNextSubscription(); |
| |
| /** |
| * Schedules a re-subscription aTimeTillNextResubscriptionMs into the future. |
| * |
| * If an application wants to set up CASE on their own, they should call ComputeTimeTillNextSubscription() to compute the next |
| * interval at which they should attempt CASE and attempt CASE at that time. On successful CASE establishment, this method |
| * should be called with the new SessionHandle provided through 'aNewSessionHandle', 'aTimeTillNextResubscriptionMs' set to 0 |
| * (i.e async, but as soon as possible) and 'aReestablishCASE' set to false. |
| * |
| * Otherwise, if aReestablishCASE is true, operational discovery and CASE will be attempted at that time before |
| * the actual IM interaction is initiated. |
| * |
| * aReestablishCASE SHALL NOT be set to true if a valid SessionHandle is provided through newSessionHandle. |
| */ |
| CHIP_ERROR ScheduleResubscription(uint32_t aTimeTillNextResubscriptionMs, Optional<SessionHandle> aNewSessionHandle, |
| bool aReestablishCASE); |
| |
| // Like SendSubscribeRequest, but allows sending certain forms of invalid |
| // subscribe requests that servers are expected to reject, for testing |
| // purposes. Should only be called from tests. |
| #if CONFIG_BUILD_FOR_HOST_UNIT_TEST |
| CHIP_ERROR SendSubscribeRequestWithoutValidation(const ReadPrepareParams & aReadPrepareParams) |
| { |
| return SendSubscribeRequestImpl(aReadPrepareParams); |
| } |
| #endif // CONFIG_BUILD_FOR_HOST_UNIT_TEST |
| |
| /** |
| * Override the interval at which liveness of the subscription is assessed. |
| * By default, this is set set to the max interval of the subscription + ACK timeout of the underlying session. |
| * |
| * This can be only be called once a subscription has been established and is active. Once called, this will cancel any existing |
| * liveness timers and schedule a new one. |
| * |
| * This can be called from the Callback::OnSubscriptionEstablished callback. |
| * |
| */ |
| void OverrideLivenessTimeout(System::Clock::Timeout aLivenessTimeout); |
| |
| private: |
| friend class TestReadInteraction; |
| friend class InteractionModelEngine; |
| |
| enum class ClientState : uint8_t |
| { |
| Idle, ///< The client has been initialized and is ready for a SendRequest |
| AwaitingInitialReport, ///< The client is waiting for initial report |
| AwaitingSubscribeResponse, ///< The client is waiting for subscribe response |
| SubscriptionActive, ///< The client is maintaining subscription |
| }; |
| |
| bool IsMatchingSubscriptionId(SubscriptionId aSubscriptionId) |
| { |
| return aSubscriptionId == mSubscriptionId && mInteractionType == InteractionType::Subscribe; |
| } |
| |
| CHIP_ERROR OnMessageReceived(Messaging::ExchangeContext * apExchangeContext, const PayloadHeader & aPayloadHeader, |
| System::PacketBufferHandle && aPayload) override; |
| void OnResponseTimeout(Messaging::ExchangeContext * apExchangeContext) override; |
| |
| /** |
| * Check if current read client is being used |
| * |
| */ |
| bool IsIdle() const { return mState == ClientState::Idle; } |
| bool IsSubscriptionActive() const { return mState == ClientState::SubscriptionActive; } |
| bool IsAwaitingInitialReport() const { return mState == ClientState::AwaitingInitialReport; } |
| bool IsAwaitingSubscribeResponse() const { return mState == ClientState::AwaitingSubscribeResponse; } |
| |
| CHIP_ERROR GenerateEventPaths(EventPathIBs::Builder & aEventPathsBuilder, const Span<EventPathParams> & aEventPaths); |
| CHIP_ERROR GenerateAttributePaths(AttributePathIBs::Builder & aAttributePathIBsBuilder, |
| const Span<AttributePathParams> & aAttributePaths); |
| |
| CHIP_ERROR GenerateDataVersionFilterList(DataVersionFilterIBs::Builder & aDataVersionFilterIBsBuilder, |
| const Span<AttributePathParams> & aAttributePaths, |
| const Span<DataVersionFilter> & aDataVersionFilters, bool & aEncodedDataVersionList); |
| CHIP_ERROR BuildDataVersionFilterList(DataVersionFilterIBs::Builder & aDataVersionFilterIBsBuilder, |
| const Span<AttributePathParams> & aAttributePaths, |
| const Span<DataVersionFilter> & aDataVersionFilters, bool & aEncodedDataVersionList); |
| CHIP_ERROR ProcessAttributeReportIBs(TLV::TLVReader & aAttributeDataIBsReader); |
| CHIP_ERROR ProcessEventReportIBs(TLV::TLVReader & aEventReportIBsReader); |
| |
| static void OnLivenessTimeoutCallback(System::Layer * apSystemLayer, void * apAppState); |
| CHIP_ERROR ProcessSubscribeResponse(System::PacketBufferHandle && aPayload); |
| CHIP_ERROR RefreshLivenessCheckTimer(); |
| void CancelLivenessCheckTimer(); |
| void CancelResubscribeTimer(); |
| void MoveToState(const ClientState aTargetState); |
| CHIP_ERROR ProcessAttributePath(AttributePathIB::Parser & aAttributePath, ConcreteDataAttributePath & aClusterInfo); |
| CHIP_ERROR ProcessReportData(System::PacketBufferHandle && aPayload); |
| const char * GetStateStr() const; |
| |
| /* |
| * Checks if we should re-subscribe based on the specified re-subscription policy. If we should, re-subscription is scheduled |
| * aNextResubscribeIntervalMsec is updated accordingly, and true is returned. |
| * |
| * If we should not resubscribe, false is returned. |
| * |
| * @param[out] aNextResubscribeIntervalMsec How long we will wait before trying to auto-resubscribe. |
| */ |
| bool ResubscribeIfNeeded(uint32_t & aNextResubscribeIntervalMsec); |
| |
| // Specialized request-sending functions. |
| CHIP_ERROR SendReadRequest(ReadPrepareParams & aReadPrepareParams); |
| // SendSubscribeRequest performs som validation on aSubscribePrepareParams |
| // and then calls SendSubscribeRequestImpl. |
| CHIP_ERROR SendSubscribeRequest(const ReadPrepareParams & aSubscribePrepareParams); |
| CHIP_ERROR SendSubscribeRequestImpl(const ReadPrepareParams & aSubscribePrepareParams); |
| void UpdateDataVersionFilters(const ConcreteDataAttributePath & aPath); |
| static void OnResubscribeTimerCallback(System::Layer * apSystemLayer, void * apAppState); |
| // Called to ensure OnReportBegin is called before calling OnEventData or OnAttributeData |
| void NoteReportingData(); |
| |
| /* |
| * Called internally to signal the completion of all work on this object, gracefully close the |
| * exchange and finally, signal to the application that it's |
| * safe to release this object. |
| * |
| * If aError != CHIP_NO_ERROR, this will trigger re-subscriptions if allowResubscription is true |
| * AND if this ReadClient instance is tracking a subscription AND the applications decides to do so |
| * in their implementation of Callback::OnResubscriptionNeeded(). |
| */ |
| void Close(CHIP_ERROR aError, bool allowResubscription = true); |
| |
| void StopResubscription(); |
| void ClearActiveSubscriptionState(); |
| |
| static void HandleDeviceConnected(void * context, Messaging::ExchangeManager & exchangeMgr, SessionHandle & sessionHandle); |
| static void HandleDeviceConnectionFailure(void * context, const ScopedNodeId & peerId, CHIP_ERROR error); |
| |
| CHIP_ERROR GetMinEventNumber(const ReadPrepareParams & aReadPrepareParams, Optional<EventNumber> & aEventMin); |
| |
| Messaging::ExchangeManager * mpExchangeMgr = nullptr; |
| Messaging::ExchangeHolder mExchange; |
| Callback & mpCallback; |
| ClientState mState = ClientState::Idle; |
| bool mIsReporting = false; |
| bool mIsInitialReport = true; |
| // boolean to check if client is waiting for the first priming report |
| bool mWaitingForFirstPrimingReport = true; |
| bool mPendingMoreChunks = false; |
| uint16_t mMinIntervalFloorSeconds = 0; |
| uint16_t mMaxInterval = 0; |
| SubscriptionId mSubscriptionId = 0; |
| ScopedNodeId mPeer; |
| InteractionType mInteractionType = InteractionType::Read; |
| Timestamp mEventTimestamp; |
| |
| bool mForceCaseOnNextResub = true; |
| |
| chip::Callback::Callback<OnDeviceConnected> mOnConnectedCallback; |
| chip::Callback::Callback<OnDeviceConnectionFailure> mOnConnectionFailureCallback; |
| |
| ReadClient * mpNext = nullptr; |
| InteractionModelEngine * mpImEngine = nullptr; |
| |
| // |
| // This stores the params associated with the interaction in a specific set of cases: |
| // 1. Stores all parameters when used with subscriptions initiated using SendAutoResubscribeRequest. |
| // 2. Stores just the SessionHolder when used with any subscriptions. |
| // |
| ReadPrepareParams mReadPrepareParams; |
| uint32_t mNumRetries = 0; |
| |
| System::Clock::Timeout mLivenessTimeoutOverride = System::Clock::kZero; |
| |
| // End Of Container (0x18) uses one byte. |
| static constexpr uint16_t kReservedSizeForEndOfContainer = 1; |
| // Reserved size for the uint8_t InteractionModelRevision flag, which takes up 1 byte for the control tag and 1 byte for the |
| // context tag, 1 byte for value |
| static constexpr uint16_t kReservedSizeForIMRevision = 1 + 1 + 1; |
| // Reserved buffer for TLV level overhead (the overhead for data version filter IBs EndOfContainer, IM reversion end |
| // of RequestMessage (another end of container)). |
| static constexpr uint16_t kReservedSizeForTLVEncodingOverhead = |
| kReservedSizeForEndOfContainer + kReservedSizeForIMRevision + kReservedSizeForEndOfContainer; |
| }; |
| |
| }; // namespace app |
| }; // namespace chip |
