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/*
*
* 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.
*/
#pragma once
#include <app/AttributePathParams.h>
#include <app/ConcreteAttributePath.h>
#include <app/InteractionModelTimeout.h>
#include <app/MessageDef/AttributeDataIBs.h>
#include <app/MessageDef/AttributeStatusIB.h>
#include <app/MessageDef/StatusIB.h>
#include <app/MessageDef/WriteRequestMessage.h>
#include <app/data-model/Encode.h>
#include <app/data-model/FabricScoped.h>
#include <app/data-model/List.h>
#include <lib/core/CHIPCore.h>
#include <lib/core/TLVDebug.h>
#include <lib/support/CodeUtils.h>
#include <lib/support/DLLUtil.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>
#include <system/TLVPacketBufferBackingStore.h>
namespace chip {
namespace app {
class InteractionModelEngine;
/**
* @brief The read client represents the initiator side of a Write Interaction, and is responsible
* for generating one Write Request for a particular set of attributes, and handling the Write response.
* Consumer can allocate one write client, then call PrepareAttribute, insert attribute value, followed by FinishAttribute for
* every attribute it wants to insert in write request, then call SendWriteRequest
*
* Note: When writing lists, you may receive multiple write status responses for a single list.
* Please see ChunkedWriteCallback.h for a high level API which will merge status codes for
* chunked write requests.
*
*/
class WriteClient : public Messaging::ExchangeDelegate
{
public:
class Callback
{
public:
virtual ~Callback() = default;
/**
* OnResponse will be called when a write response has been received
* and processed for the given path.
*
* The WriteClient object MUST continue to exist after this call is completed. The application shall wait until it
* receives an OnDone call before it shuts down the object.
*
* @param[in] apWriteClient The write client object that initiated the write transaction.
* @param[in] aPath The attribute path field in write response.
* @param[in] attributeStatus Attribute-specific status, containing an InteractionModel::Status code as well as
* an optional cluster-specific status code.
*/
virtual void OnResponse(const WriteClient * apWriteClient, const ConcreteDataAttributePath & aPath,
StatusIB attributeStatus)
{}
/**
* OnError will be called when an error occurs *after* a successful call to SendWriteRequest(). 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.
*
* The WriteClient object MUST continue to exist after this call is completed. The application shall wait until it
* receives an OnDone call before it shuts down the object.
*
* @param[in] apWriteClient The write client object that initiated the attribute write transaction.
* @param[in] aError A system error code that conveys the overall error code.
*/
virtual void OnError(const WriteClient * apWriteClient, CHIP_ERROR aError) {}
/**
* OnDone will be called when WriteClient has finished all work and is reserved for future WriteClient ownership change.
* (#10366) Users may use this function to release their own objects related to this write interaction.
*
* This function will:
* - Always be called exactly *once* for a given WriteClient instance.
* - Be called even in error circumstances.
* - Only be called after a successful call to SendWriteRequest has been made.
*
* @param[in] apWriteClient The write client object of the terminated write transaction.
*/
virtual void OnDone(WriteClient * apWriteClient) = 0;
};
/**
* Construct the client object. Within the lifetime
* of this instance.
*
* @param[in] apExchangeMgr A pointer to the ExchangeManager object.
* @param[in] apCallback Callback set by application.
* @param[in] aTimedWriteTimeoutMs If provided, do a timed write using this timeout.
* @param[in] aSuppressResponse If provided, set SuppressResponse field to the provided value
*/
WriteClient(Messaging::ExchangeManager * apExchangeMgr, Callback * apCallback, const Optional<uint16_t> & aTimedWriteTimeoutMs,
bool aSuppressResponse = false) :
mpExchangeMgr(apExchangeMgr),
mExchangeCtx(*this), mpCallback(apCallback), mTimedWriteTimeoutMs(aTimedWriteTimeoutMs),
mSuppressResponse(aSuppressResponse)
{}
#if CONFIG_BUILD_FOR_HOST_UNIT_TEST
WriteClient(Messaging::ExchangeManager * apExchangeMgr, Callback * apCallback, const Optional<uint16_t> & aTimedWriteTimeoutMs,
uint16_t aReservedSize) :
mpExchangeMgr(apExchangeMgr),
mExchangeCtx(*this), mpCallback(apCallback), mTimedWriteTimeoutMs(aTimedWriteTimeoutMs), mReservedSize(aReservedSize)
{}
#endif
/**
* Encode an attribute value that can be directly encoded using DataModel::Encode. Will create a new chunk when necessary.
*/
template <class T>
CHIP_ERROR EncodeAttribute(const AttributePathParams & attributePath, const T & value,
const Optional<DataVersion> & aDataVersion = NullOptional)
{
ReturnErrorOnFailure(EnsureMessage());
// Here, we are using kInvalidEndpointId for missing endpoint id, which is used when sending group write requests.
return EncodeSingleAttributeDataIB(
ConcreteDataAttributePath(attributePath.HasWildcardEndpointId() ? kInvalidEndpointId : attributePath.mEndpointId,
attributePath.mClusterId, attributePath.mAttributeId, aDataVersion),
value);
}
/**
* Encode a possibly-chunked list attribute value. Will create a new chunk when necessary.
*/
template <class T>
CHIP_ERROR EncodeAttribute(const AttributePathParams & attributePath, const DataModel::List<T> & value,
const Optional<DataVersion> & aDataVersion = NullOptional)
{
// Here, we are using kInvalidEndpointId for missing endpoint id, which is used when sending group write requests.
ConcreteDataAttributePath path =
ConcreteDataAttributePath(attributePath.HasWildcardEndpointId() ? kInvalidEndpointId : attributePath.mEndpointId,
attributePath.mClusterId, attributePath.mAttributeId, aDataVersion);
ReturnErrorOnFailure(EnsureMessage());
// Encode an empty list for the chunking protocol.
ReturnErrorOnFailure(EncodeSingleAttributeDataIB(path, DataModel::List<uint8_t>()));
path.mListOp = ConcreteDataAttributePath::ListOperation::AppendItem;
for (ListIndex i = 0; i < value.size(); i++)
{
ReturnErrorOnFailure(EncodeSingleAttributeDataIB(path, value.data()[i]));
}
return CHIP_NO_ERROR;
}
/**
* Encode a Nullable attribute value. This needs a separate overload so it can dispatch to the right
* EncodeAttribute when writing a nullable list.
*/
template <class T>
CHIP_ERROR EncodeAttribute(const AttributePathParams & attributePath, const DataModel::Nullable<T> & value,
const Optional<DataVersion> & aDataVersion = NullOptional)
{
ReturnErrorOnFailure(EnsureMessage());
if (value.IsNull())
{
// Here, we are using kInvalidEndpointId to for missing endpoint id, which is used when sending group write requests.
return EncodeSingleAttributeDataIB(
ConcreteDataAttributePath(attributePath.HasWildcardEndpointId() ? kInvalidEndpointId : attributePath.mEndpointId,
attributePath.mClusterId, attributePath.mAttributeId, aDataVersion),
value);
}
return EncodeAttribute(attributePath, value.Value(), aDataVersion);
}
/**
* Encode an attribute value which is already encoded into a TLV. The TLVReader is expected to be initialized and the read head
* is expected to point to the element to be encoded.
*
* Note: When encoding lists with this function, you may receive more than one write status for a single list. You can refer
* to ChunkedWriteCallback.h for a high level API which will merge status codes for chunked write requests.
*/
CHIP_ERROR PutPreencodedAttribute(const ConcreteDataAttributePath & attributePath, const TLV::TLVReader & data);
/**
* Once SendWriteRequest returns successfully, the WriteClient will
* handle calling Shutdown on itself once it decides it's done with waiting
* for a response (i.e. times out or gets a response). Client can specify
* the maximum time to wait for response (in milliseconds) via timeout parameter.
* If the timeout is missing or is set to System::Clock::kZero, a value based on the MRP timeouts of the session will be used.
* If SendWriteRequest is never called, or the call fails, the API
* consumer is responsible for calling Shutdown on the WriteClient.
*/
CHIP_ERROR SendWriteRequest(const SessionHandle & session, System::Clock::Timeout timeout = System::Clock::kZero);
/**
* Shutdown the WriteClient. This terminates this instance
* of the object and releases all held resources.
*/
void Shutdown();
private:
friend class TestWriteInteraction;
friend class InteractionModelEngine;
enum class State
{
Initialized = 0, // The client has been initialized
AddAttribute, // The client has added attribute and ready for a SendWriteRequest
AwaitingTimedStatus, // Sent a Tiemd Request, waiting for response.
AwaitingResponse, // The client has sent out the write request message
ResponseReceived, // We have gotten a response after sending write request
AwaitingDestruction, // The object has completed its work and is awaiting destruction by the application.
};
CHIP_ERROR OnMessageReceived(Messaging::ExchangeContext * apExchangeContext, const PayloadHeader & aPayloadHeader,
System::PacketBufferHandle && aPayload) override;
void OnResponseTimeout(Messaging::ExchangeContext * apExchangeContext) override;
void MoveToState(const State aTargetState);
CHIP_ERROR ProcessWriteResponseMessage(System::PacketBufferHandle && payload);
CHIP_ERROR ProcessAttributeStatusIB(AttributeStatusIB::Parser & aAttributeStatusIB);
const char * GetStateStr() const;
/**
* Encode an attribute value that can be directly encoded using DataModel::Encode.
*/
template <class T, std::enable_if_t<!DataModel::IsFabricScoped<T>::value, int> = 0>
CHIP_ERROR TryEncodeSingleAttributeDataIB(const ConcreteDataAttributePath & attributePath, const T & value)
{
chip::TLV::TLVWriter * writer = nullptr;
ReturnErrorOnFailure(PrepareAttributeIB(attributePath));
VerifyOrReturnError((writer = GetAttributeDataIBTLVWriter()) != nullptr, CHIP_ERROR_INCORRECT_STATE);
ReturnErrorOnFailure(
DataModel::Encode(*writer, chip::TLV::ContextTag(to_underlying(chip::app::AttributeDataIB::Tag::kData)), value));
ReturnErrorOnFailure(FinishAttributeIB());
return CHIP_NO_ERROR;
}
template <class T, std::enable_if_t<DataModel::IsFabricScoped<T>::value, int> = 0>
CHIP_ERROR TryEncodeSingleAttributeDataIB(const ConcreteDataAttributePath & attributePath, const T & value)
{
chip::TLV::TLVWriter * writer = nullptr;
ReturnErrorOnFailure(PrepareAttributeIB(attributePath));
VerifyOrReturnError((writer = GetAttributeDataIBTLVWriter()) != nullptr, CHIP_ERROR_INCORRECT_STATE);
ReturnErrorOnFailure(DataModel::EncodeForWrite(
*writer, chip::TLV::ContextTag(to_underlying(chip::app::AttributeDataIB::Tag::kData)), value));
ReturnErrorOnFailure(FinishAttributeIB());
return CHIP_NO_ERROR;
}
/**
* A wrapper for TryEncodeSingleAttributeDataIB which will start a new chunk when failed with CHIP_ERROR_NO_MEMORY or
* CHIP_ERROR_BUFFER_TOO_SMALL.
*/
template <class T>
CHIP_ERROR EncodeSingleAttributeDataIB(const ConcreteDataAttributePath & attributePath, const T & value)
{
TLV::TLVWriter backupWriter;
mWriteRequestBuilder.GetWriteRequests().Checkpoint(backupWriter);
// First attempt to write this attribute.
CHIP_ERROR err = TryEncodeSingleAttributeDataIB(attributePath, value);
if (err == CHIP_ERROR_NO_MEMORY || err == CHIP_ERROR_BUFFER_TOO_SMALL)
{
// If it failed with no memory, then we create a new chunk for it.
mWriteRequestBuilder.GetWriteRequests().Rollback(backupWriter);
mWriteRequestBuilder.GetWriteRequests().ResetError();
ReturnErrorOnFailure(StartNewMessage());
ReturnErrorOnFailure(TryEncodeSingleAttributeDataIB(attributePath, value));
}
else
{
ReturnErrorOnFailure(err);
}
return CHIP_NO_ERROR;
}
/**
* Encode a preencoded attribute data, returns TLV encode error if the ramaining space of current chunk is too small for the
* AttributeDataIB.
*/
CHIP_ERROR TryPutSinglePreencodedAttributeWritePayload(const ConcreteDataAttributePath & attributePath,
const TLV::TLVReader & data);
/**
* Encode a preencoded attribute data, will try to create a new chunk when necessary.
*/
CHIP_ERROR PutSinglePreencodedAttributeWritePayload(const ConcreteDataAttributePath & attributePath,
const TLV::TLVReader & data);
CHIP_ERROR EnsureMessage();
/**
* Called internally to signal the completion of all work on this object, gracefully close the
* exchange (by calling into the base class) and finally, signal to the application that it's
* safe to release this object.
*/
void Close();
/**
* This forcibly closes the exchange context if a valid one is pointed to. Such a situation does
* not arise during normal message processing flows that all normally call Close() above. This can only
* arise due to application-initiated destruction of the object when this object is handling receiving/sending
* message payloads.
*/
void Abort();
// Send our queued-up Write Request message. Assumes the exchange is ready
// and mPendingWriteData is populated.
CHIP_ERROR SendWriteRequest();
// Encodes the header of an AttributeDataIB, a special case for attributePath is its EndpointId can be kInvalidEndpointId, this
// is used when sending group write requests.
// TODO(#14935) Update AttributePathParams to support more list operations.
CHIP_ERROR PrepareAttributeIB(const ConcreteDataAttributePath & attributePath);
CHIP_ERROR FinishAttributeIB();
TLV::TLVWriter * GetAttributeDataIBTLVWriter();
/**
* Create a new message (or a new chunk) for the write request.
*/
CHIP_ERROR StartNewMessage();
/**
* Finalize Write Request Message TLV Builder and retrieve final data from tlv builder for later sending
*/
CHIP_ERROR FinalizeMessage(bool aHasMoreChunks);
Messaging::ExchangeManager * mpExchangeMgr = nullptr;
Messaging::ExchangeHolder mExchangeCtx;
Callback * mpCallback = nullptr;
State mState = State::Initialized;
System::PacketBufferTLVWriter mMessageWriter;
WriteRequestMessage::Builder mWriteRequestBuilder;
// TODO Maybe we should change PacketBufferTLVWriter so we can finalize it
// but have it hold on to the buffer, and get the buffer from it later.
// Then we could avoid this extra pointer-sized member.
System::PacketBufferHandle mPendingWriteData;
// If mTimedWriteTimeoutMs has a value, we are expected to do a timed
// write.
Optional<uint16_t> mTimedWriteTimeoutMs;
bool mSuppressResponse = false;
// A list of buffers, one buffer for each chunk.
System::PacketBufferHandle mChunks;
// TODO: This file might be compiled with different build flags on Darwin platform (when building WriteClient.cpp and
// CHIPClustersObjc.mm), which will cause undefined behavior when building write requests. Uncomment the #if and #endif after
// resolving it.
// #if CONFIG_BUILD_FOR_HOST_UNIT_TEST
uint16_t mReservedSize = 0;
// #endif
/**
* Below we define several const variables for encoding overheads.
* WriteRequestMessage =
* {
* timedRequest = false,
* AttributeDataIBs =
* [
* AttributeDataIB = \
* { |
* DataVersion = 0x0, |
* AttributePathIB = |
* { |
* Endpoint = 0x2, | "atomically" encoded via
* Cluster = 0x50f, > EncodeAttribute or
* Attribute = 0x0000_0006, | PutPreencodedAttribute
* ListIndex = Null, |
* } |
* Data = ... |
* }, /
* (...)
* ], <-- 1 byte "end of AttributeDataIB" (end of container)
* moreChunkedMessages = false, <-- 2 bytes "kReservedSizeForMoreChunksFlag"
* InteractionModelRevision = 1,<-- 3 bytes "kReservedSizeForIMRevision"
* } <-- 1 byte "end of WriteRequestMessage" (end of container)
*/
// Reserved size for the MoreChunks boolean flag, which takes up 1 byte for the control tag and 1 byte for the context tag.
static constexpr uint16_t kReservedSizeForMoreChunksFlag = 1 + 1;
// 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 end of AttributeDataIBs (end of container), more chunks flag, end
// of WriteRequestMessage (another end of container)).
static constexpr uint16_t kReservedSizeForTLVEncodingOverhead = kReservedSizeForIMRevision + kReservedSizeForMoreChunksFlag +
kReservedSizeForEndOfContainer + kReservedSizeForEndOfContainer;
bool mHasDataVersion = false;
};
} // namespace app
} // namespace chip