#include "comms/protocol/MsgDataLayer.h"

Detailed Description

template<typename... TExtraOpts>
class comms::protocol::MsgDataLayer< TExtraOpts >

Message data layer.

Must always be the last layer in protocol stack.

Template Parameters

TExtraOpts Extra options to inner Field type which is defined to be comms::field::ArrayList. This field is used only in AllFields type and readFieldsCached() member function.

Public Types
using	AllFields = std::tuple< Field >
	All fields of the remaining transport layers, contains only Field.

using	AllMessages = void
	Default value of AllMessages type.

using	Field = comms::field::ArrayList< comms::Field< comms::option::def::BigEndian >, std::uint8_t, TExtraOpts... >
	Raw data field type.

using	MsgFactory = void
	Default value of MsgFactory type.

using	ThisLayer = MsgDataLayer< TExtraOpts... >
	Type of this layer.

Public Member Functions
	MsgDataLayer ()=default
	Default constructor.

	MsgDataLayer (const MsgDataLayer &)=default
	Copy constructor.

	MsgDataLayer (MsgDataLayer &&)=default
	Move constructor.

	~MsgDataLayer () noexcept=default
	Destructor.

MsgDataLayer &	operator= (const MsgDataLayer &)=default
	Copy assignment operator.

MsgDataLayer &	operator= (MsgDataLayer &&)=default
	Move assignment operator.

ThisLayer &	thisLayer ()
	Get access to this layer object.

const ThisLayer &	thisLayer () const
	Get "const" access to this layer object.

Static Public Member Functions
template<typename TAllFields >
static auto	accessCachedField (TAllFields &allFields) -> decltype(std::get< std::tuple_size< typename std::decay< TAllFields >::type >::value - std::tuple_size< AllFields >::value >(allFields))
	Access appropriate field from "cached" bundle of all the protocol stack fields.

static constexpr bool	canSplitRead ()
	Compile time check whether split read "until" and "from" data layer is allowed.

static constexpr std::size_t	length ()
	Get remaining length of wrapping transport information.

template<typename TMsg >
static constexpr std::size_t	length (const TMsg &msg)
	Get remaining length of wrapping transport information + length of the provided message.

template<typename TMsg , typename TIter , typename... TExtraValues>
static ErrorStatus	read (TMsg &msg, TIter &iter, std::size_t size, TExtraValues... extraValues)
	Read the message contents.

template<typename TAllFields , typename TMsg , typename TIter , typename... TExtraValues>
static ErrorStatus	readFieldsCached (TAllFields &allFields, TMsg &msg, TIter &iter, std::size_t size, TExtraValues... extraValues)
	Read the message contents while caching the read transport information fields.

template<typename TMsg , typename TIter , typename... TExtraValues>
static ErrorStatus	readFromData (TMsg &msg, TIter &iter, std::size_t size, TExtraValues... extraValues)
	Same as read().

template<typename TAllFields , typename TMsg , typename TIter , typename... TExtraValues>
static ErrorStatus	readFromDataFeildsCached (TAllFields &allFields, TMsg &msg, TIter &iter, std::size_t size, TExtraValues... extraValues)
	Same as readFieldsCached().

template<typename TMsg , typename TIter , typename... TExtraValues>
static ErrorStatus	readUntilData (TMsg &msg, TIter &iter, std::size_t size, TExtraValues...)
	Read transport fields until data layer.

template<typename TAllFields , typename TMsg , typename TIter , typename... TExtraValues>
static ErrorStatus	readUntilDataFieldsCached (TAllFields &allFields, TMsg &msg, TIter &iter, std::size_t size, TExtraValues...)
	Read transport fields with caching until data layer.

template<typename TMsg , typename TIter >
static comms::ErrorStatus	update (const TMsg &msg, TIter &iter, std::size_t size)
	Update recently written (using write()) message contents data.

template<typename TIter >
static comms::ErrorStatus	update (TIter &iter, std::size_t size)
	Update recently written (using write()) message contents data.

template<typename TAllFields , typename TMsg , typename TIter >
static ErrorStatus	updateFieldsCached (TAllFields &allFields, const TMsg &msg, TIter &iter, std::size_t size)
	Update recently written (using writeFieldsCached()) message data as well as cached transport information fields.

template<typename TAllFields , typename TIter >
static ErrorStatus	updateFieldsCached (TAllFields &allFields, TIter &iter, std::size_t size)
	Update recently written (using writeFieldsCached()) message data as well as cached transport information fields.

template<typename TMsg , typename TIter >
static ErrorStatus	write (const TMsg &msg, TIter &iter, std::size_t size)
	Write the message contents.

template<typename TAllFields , typename TMsg , typename TIter >
static ErrorStatus	writeFieldsCached (TAllFields &allFields, const TMsg &msg, TIter &iter, std::size_t size)
	Write the message contents while caching the written transport information fields.

Static Public Attributes
static const std::size_t	NumOfLayers = 1
	Static constant indicating amount of transport layers used.

Related Symbols
(Note that these are not member symbols.)
template<typename T >
constexpr bool	isMsgDataLayer ()
	Compile time check of whether the provided type is a variant of MsgDataLayer.

Member Typedef Documentation

◆ AllMessages

template<typename... TExtraOpts>

using comms::protocol::MsgDataLayer< TExtraOpts >::AllMessages = void

Default value of AllMessages type.

Defined as void.

◆ Field

template<typename... TExtraOpts>

using comms::protocol::MsgDataLayer< TExtraOpts >::Field = comms::field::ArrayList< comms::Field<comms::option::def::BigEndian>, std::uint8_t, TExtraOpts... >

Raw data field type.

This field is used only in AllFields field and readFieldsCached() member function.

◆ MsgFactory

template<typename... TExtraOpts>

using comms::protocol::MsgDataLayer< TExtraOpts >::MsgFactory = void

Default value of MsgFactory type.

Defined as void.

Member Function Documentation

◆ accessCachedField()

template<typename... TExtraOpts>

template<typename TAllFields >

static auto comms::protocol::MsgDataLayer< TExtraOpts >::accessCachedField ( TAllFields & allFields ) -> decltype(std::get<std::tuple_size<typename std::decay<TAllFields>::type>::value - std::tuple_size<AllFields>::value>(allFields))

static

Access appropriate field from "cached" bundle of all the protocol stack fields.

Parameters

allFields All fields of the protocol stack

Returns: Reference to requested field.

◆ canSplitRead()

template<typename... TExtraOpts>

static constexpr bool comms::protocol::MsgDataLayer< TExtraOpts >::canSplitRead ( )

staticconstexpr

Compile time check whether split read "until" and "from" data layer is allowed.

Returns: Always true.

◆ length() [1/2]

template<typename... TExtraOpts>

static constexpr std::size_t comms::protocol::MsgDataLayer< TExtraOpts >::length ( )

staticconstexpr

Get remaining length of wrapping transport information.

The message data always get wrapped with transport information to be successfully delivered to and unpacked on the other side. This function return remaining length of the transport information.

Returns: 0.

◆ length() [2/2]

template<typename... TExtraOpts>

template<typename TMsg >

static constexpr std::size_t comms::protocol::MsgDataLayer< TExtraOpts >::length ( const TMsg & msg )

staticconstexpr

Get remaining length of wrapping transport information + length of the provided message.

This function usually gets called when there is a need to identify the size of the buffer required to write provided message wrapped in the transport information. This function is very similar to length(), but adds also length of the message.

Parameters

[in] msg Message

Returns: Length of the message.

◆ read()

template<typename... TExtraOpts>

template<typename TMsg , typename TIter , typename... TExtraValues>

static ErrorStatus comms::protocol::MsgDataLayer< TExtraOpts >::read	(	TMsg &	msg,
		TIter &	iter,
		std::size_t	size,
		TExtraValues...	extraValues
	)

static

Read the message contents.

Calls the read() member function of the message object.

Template Parameters

TMsg	Type of the msg parameter.
TIter	Type of iterator used for reading.

Parameters

[in]	msg	Reference to the smart pointer holding message object or to the message object itself.
[in,out]	iter	Iterator used for reading.
[in]	size	Number of bytes available for reading.
[out]	extraValues	Extra output parameters provided using one of the following functions comms::protocol::missingSize() comms::protocol::msgId() comms::protocol::msgIndex() comms::protocol::msgPayload()

Returns: Status of the read operation.

Precondition: If msg is a smart pointer to message object, it must point to a real object.

Postcondition: missingSize output value is updated if and only if function returns comms::ErrorStatus::NotEnoughData.

◆ readFieldsCached()

template<typename... TExtraOpts>

template<typename TAllFields , typename TMsg , typename TIter , typename... TExtraValues>

static ErrorStatus comms::protocol::MsgDataLayer< TExtraOpts >::readFieldsCached	(	TAllFields &	allFields,
		TMsg &	msg,
		TIter &	iter,
		std::size_t	size,
		TExtraValues...	extraValues
	)

static

Read the message contents while caching the read transport information fields.

Very similar to read() member function, but adds "allFields" parameter to store raw data of the message.

Template Parameters

TIdx	Index of the data field in TAllFields, expected to be last element in the tuple.
TAllFields	std::tuple of all the transport fields, must be AllFields type defined in the last layer class that defines protocol stack.
TMsg	Type of the msg parameter
TIter	Type of iterator used for reading.

Parameters

[out]	allFields	Reference to the std::tuple object that wraps all transport fields (AllFields type of the last protocol layer class).
[in]	msg	Reference to the smart pointer holding message object or to the message object itself.
[in,out]	iter	Iterator used for reading.
[in]	size	Number of bytes available for reading.
[out]	extraValues	Extra output parameters provided using one of the following functions comms::protocol::missingSize() comms::protocol::msgId() comms::protocol::msgIndex() comms::protocol::msgPayload()

Returns: Status of the read operation.

◆ readFromData()

template<typename... TExtraOpts>

template<typename TMsg , typename TIter , typename... TExtraValues>

static ErrorStatus comms::protocol::MsgDataLayer< TExtraOpts >::readFromData	(	TMsg &	msg,
		TIter &	iter,
		std::size_t	size,
		TExtraValues...	extraValues
	)

static

Same as read().

Expected to be called by the privous layers to properly finalise read operation after the call to readUntilData();

Returns: comms::ErrorStatus::Success;

◆ readFromDataFeildsCached()

template<typename... TExtraOpts>

template<typename TAllFields , typename TMsg , typename TIter , typename... TExtraValues>

static ErrorStatus comms::protocol::MsgDataLayer< TExtraOpts >::readFromDataFeildsCached	(	TAllFields &	allFields,
		TMsg &	msg,
		TIter &	iter,
		std::size_t	size,
		TExtraValues...	extraValues
	)

static

Same as readFieldsCached().

Expected to be called by the privous layers to properly finalise read operation after the call to readUntilDataFieldsCached();

Returns: comms::ErrorStatus::Success;

◆ readUntilData()

template<typename... TExtraOpts>

template<typename TMsg , typename TIter , typename... TExtraValues>

static ErrorStatus comms::protocol::MsgDataLayer< TExtraOpts >::readUntilData	(	TMsg &	msg,
		TIter &	iter,
		std::size_t	size,
		TExtraValues...
	)

static

Read transport fields until data layer.

Does nothing because it is data layer.

Returns: comms::ErrorStatus::Success;

◆ readUntilDataFieldsCached()

template<typename... TExtraOpts>

template<typename TAllFields , typename TMsg , typename TIter , typename... TExtraValues>

static ErrorStatus comms::protocol::MsgDataLayer< TExtraOpts >::readUntilDataFieldsCached	(	TAllFields &	allFields,
		TMsg &	msg,
		TIter &	iter,
		std::size_t	size,
		TExtraValues...
	)

static

Read transport fields with caching until data layer.

Does nothing because it is data layer.

Returns: comms::ErrorStatus::Success;

◆ update() [1/2]

template<typename... TExtraOpts>

template<typename TMsg , typename TIter >

static comms::ErrorStatus comms::protocol::MsgDataLayer< TExtraOpts >::update	(	const TMsg &	msg,
		TIter &	iter,
		std::size_t	size
	)

static

Update recently written (using write()) message contents data.

Same as other update(), but with extra message parameter/

Parameters

[in]	msg	Reference to recently writtem message object.
[in,out]	iter	Any random access iterator.
[in]	size	Number of bytes that have been written using write().

Returns: Status of the update operation.

◆ update() [2/2]

template<typename... TExtraOpts>

template<typename TIter >

static comms::ErrorStatus comms::protocol::MsgDataLayer< TExtraOpts >::update	(	TIter &	iter,
		std::size_t	size
	)

static

Update recently written (using write()) message contents data.

Sometimes, when NON random access iterator is used for writing (for example std::back_insert_iterator), some transport data cannot be properly written. In this case, write() function will return comms::ErrorStatus::UpdateRequired. When such status is returned it is necessary to call update() with random access iterator on the written buffer to update written dummy information with proper values. This function in this layer does nothing, just advances the iterator by "size".

Parameters

[in,out]	iter	Any random access iterator.
[in]	size	Number of bytes that have been written using write().

Returns: Status of the update operation.

◆ updateFieldsCached() [1/2]

template<typename... TExtraOpts>

template<typename TAllFields , typename TMsg , typename TIter >

static ErrorStatus comms::protocol::MsgDataLayer< TExtraOpts >::updateFieldsCached	(	TAllFields &	allFields,
		const TMsg &	msg,
		TIter &	iter,
		std::size_t	size
	)

static

Update recently written (using writeFieldsCached()) message data as well as cached transport information fields.

Very similar to other updateFieldsCached() member function, but adds "msg" parameter to reference message object if needed.

Template Parameters

TAllFields	std::tuple of all the transport fields, must be AllFields type defined in the last layer class that defines protocol stack.
TMsg	Type of msg parameter.
TIter	Type of the random access iterator.

Parameters

[out]	allFields	Reference to the std::tuple object that wraps all transport fields (AllFields type of the last protocol layer class).
[in]	msg	Reference to recently written message object.
[in,out]	iter	Random access iterator to the written data.
[in]	size	Number of bytes that have been written using writeFieldsCached().

Returns: Status of the update operation.

◆ updateFieldsCached() [2/2]

template<typename... TExtraOpts>

template<typename TAllFields , typename TIter >

static ErrorStatus comms::protocol::MsgDataLayer< TExtraOpts >::updateFieldsCached	(	TAllFields &	allFields,
		TIter &	iter,
		std::size_t	size
	)

static

Update recently written (using writeFieldsCached()) message data as well as cached transport information fields.

Very similar to update() member function, but adds "allFields" parameter to store raw data of the message.

Template Parameters

TAllFields	std::tuple of all the transport fields, must be AllFields type defined in the last layer class that defines protocol stack.
TIter	Type of the random access iterator.

Parameters

[out]	allFields	Reference to the std::tuple object that wraps all transport fields (AllFields type of the last protocol layer class).
[in,out]	iter	Random access iterator to the written data.
[in]	size	Number of bytes that have been written using writeFieldsCached().

Returns: Status of the update operation.

◆ write()

template<typename... TExtraOpts>

template<typename TMsg , typename TIter >

static ErrorStatus comms::protocol::MsgDataLayer< TExtraOpts >::write	(	const TMsg &	msg,
		TIter &	iter,
		std::size_t	size
	)

static

Write the message contents.

The way the message contents are written is determined by the type of the message. If TMsg type is recognised to be actual message inheriting from comms::MessageBase with its fields provided using comms::option::def::FieldsImpl option, the function calls doWrite non-virtual function defined by comms::MessageBase (see comms::MessageBase::doWrite) or redefined by the actual message itself. Otherwise, TMsg type is expected to be the used interface which allows polymorphic write functionality. It must define write() member function which will be called.

Template Parameters

TMsg	Type of the message.
TIter	Type of the iterator used for writing.

Parameters

[in]	msg	Reference to the message object,
[in,out]	iter	Iterator used for writing.
[in]	size	Max number of bytes that can be written.

Returns: Status of the write operation.

◆ writeFieldsCached()

template<typename... TExtraOpts>

template<typename TAllFields , typename TMsg , typename TIter >

static ErrorStatus comms::protocol::MsgDataLayer< TExtraOpts >::writeFieldsCached	(	TAllFields &	allFields,
		const TMsg &	msg,
		TIter &	iter,
		std::size_t	size
	)

static

Write the message contents while caching the written transport information fields.

Very similar to write() member function, but adds "allFields" parameter to store raw data of the message.

Template Parameters

TAllFields	std::tuple of all the transport fields, must be AllFields type defined in the last layer class that defines protocol stack.
TMsg	Type of the message.
TIter	Type of the iterator used for writing.

Parameters

[out]	allFields	Reference to the std::tuple object that wraps all transport fields (AllFields type of the last protocol layer class).
[in]	msg	Reference to the message object that is being written,
[in,out]	iter	Iterator used for writing.
[in]	size	Max number of bytes that can be written.

Returns: Status of the write operation.

The documentation for this class was generated from the following file:

include/comms/protocol/MsgDataLayer.h

Detailed Description

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Related Symbols

Member Typedef Documentation

◆ AllMessages

◆ Field

◆ MsgFactory

Member Function Documentation

◆ accessCachedField()

◆ canSplitRead()

◆ length() [1/2]

◆ length() [2/2]

◆ read()

◆ readFieldsCached()

◆ readFromData()

◆ readFromDataFeildsCached()

◆ readUntilData()

◆ readUntilDataFieldsCached()

◆ update() [1/2]

◆ update() [2/2]

◆ updateFieldsCached() [1/2]

◆ updateFieldsCached() [2/2]

◆ write()

◆ writeFieldsCached()