Namespace that contains definition of layers that can be used to wrap message data with transport data. More...

Detailed Description

Namespace that contains definition of layers that can be used to wrap message data with transport data.

Namespaces
namespace	checksum
	Namespace that contains definition of checksum calculator classes which can be used with comms::protocol::ChecksumLayer transport layer class.

Classes
class	ChecksumLayer
	Protocol layer that is responsible to calculate checksum on the data written by all the wrapped internal layers and append it to the end of the written data. When reading, this layer is responsible to verify the checksum reported at the end of the read data. More...

class	ChecksumPrefixLayer
	Protocol layer that is responsible to calculate checksum on the data written by all the wrapped internal layers and prepend it before the written data. When reading, this layer is responsible to verify the checksum reported at the beginning of the read data. More...

class	MsgDataLayer
	Message data layer. More...

class	MsgIdLayer
	Protocol layer that uses uses message ID field as a prefix to all the subsequent data written by other (next) layers. More...

class	MsgSizeLayer
	Protocol layer that uses size field as a prefix to all the subsequent data written by other (next) layers. More...

class	ProtocolLayerBase
	Base class for all the middle (non MsgDataLayer) protocol transport layers. More...

class	SyncPrefixLayer
	Protocol layer that uses "sync" field as a prefix to all the subsequent data written by other (next) layers. More...

class	TransportValueLayer
	Protocol layer that reads a value from transport wrapping and reassigns it to appropriate "extra transport" data member of the created message object. More...

Functions
details::MissingSizeRetriever	missingSize (std::size_t &val)
	Add "missing size" output parameter to protocol stack's (frame's) "read" operation.

template<typename TId >
details::MsgIdRetriever< TId >	msgId (TId &val)
	Add "message ID" output parameter to protocol stack's (frame's) "read" operation.

details::MsgIndexRetriever	msgIndex (std::size_t &val)
	Add "message index" output parameter to protocol stack's (frame's) "read" operation.

template<typename TIter >
details::MsgPayloadRetriever< TIter >	msgPayload (TIter &iter, std::size_t &len)
	Add "payload start" and "payload size" output parameters to protocol stack's (frame's) "read" operation.

template<typename TField , typename TNextLayer , typename TDerived , typename... TOptions>
constexpr const ProtocolLayerBase< TField, TNextLayer, TDerived, TOptions... > &	toProtocolLayerBase (const ProtocolLayerBase< TField, TNextLayer, TDerived, TOptions... > &layer)
	Upcast protocol layer in order to have access to its internal types.

template<typename TField , typename TNextLayer , typename TDerived , typename... TOptions>
ProtocolLayerBase< TField, TNextLayer, TDerived, TOptions... > &	toProtocolLayerBase (ProtocolLayerBase< TField, TNextLayer, TDerived, TOptions... > &layer)
	Upcast protocol layer in order to have access to its internal types.

Function Documentation

◆ missingSize()

details::MissingSizeRetriever comms::protocol::missingSize ( std::size_t & val )

Add "missing size" output parameter to protocol stack's (frame's) "read" operation.

Can be passed as variadic parameters to "read" functions of protocol stack (see comms::protocol::ProtocolLayerBase::read() and comms::protocol::ProtocolLayerBase::readFieldsCached()). It can be used to retrieve missing length information in case "read" of protocol stack operation returns comms::ErrorStatus::NotEnoughData.

using ProtocolStack = ...
ProtocolStack stack;
ProtocolStack::MsgPtr msg;
std::size_t missingSize = 0U;
auto es = stack.read(msg, readIter, size, comms::protocol::missingSize(missingSize));
if (es == comms::ErrorStatus::NotEnoughData) {
    ... // missingSize will hold a minimal number of bytes that are required to be yet read
}

Parameters

[out] val Missing size value to be returned.

Returns: Implementation dependent object accepted by "read" functions.

See also: comms::protocol::ProtocolLayerBase::read(); comms::protocol::ProtocolLayerBase::readFieldsCached()

◆ msgId()

template<typename TId >

details::MsgIdRetriever< TId > comms::protocol::msgId ( TId & val )

Add "message ID" output parameter to protocol stack's (frame's) "read" operation.

Can be passed as variadic parameters to "read" functions of protocol stack (see comms::protocol::ProtocolLayerBase::read() and comms::protocol::ProtocolLayerBase::readFieldsCached()). It can be used to retrieve numeric message ID value.

using ProtocolStack = ...
ProtocolStack stack;
ProtocolStack::MsgPtr msg;
my_prot::MsgId msgId = my_prot::MsgId();
auto es = stack.read(msg, readIter, size, comms::protocol::msgId(msgId));
if (es == comms::ErrorStatus::Success) {
    assert(msg); // Message object must be created
    ... // use msgId value
}

Parameters

[out] val Numeric message ID value to be returned.

Returns: Implementation dependent object accepted by "read" functions.

See also: comms::protocol::ProtocolLayerBase::read(); comms::protocol::ProtocolLayerBase::readFieldsCached()

◆ msgIndex()

details::MsgIndexRetriever comms::protocol::msgIndex ( std::size_t & val )

Add "message index" output parameter to protocol stack's (frame's) "read" operation.

In case the expected input message types tuple contains multiple different message classes but having the same numeric ID, it may be beneficial to know the reletive index (starting from the first message type having the same ID) of the detected message. This function can be used to retrieve such information. Can be passed as variadic parameters to "read" functions of protocol stack (see comms::protocol::ProtocolLayerBase::read() and comms::protocol::ProtocolLayerBase::readFieldsCached()).

using ProtocolStack = ...
ProtocolStack stack;
ProtocolStack::MsgPtr msg;
my_prot::MsgId msgId = my_prot::MsgId();
std::size_t msgIndex = 0U;
auto es =
   stack.read(
       msg,
       readIter,
       size,
       comms::protocol::msgId(msgId),
       comms::protocol::msgIndex(msgIndex));
if (es == comms::ErrorStatus::Success) {
    assert(msg); // Message object must be created
    ... // use msgId and msgIndex values
}

Parameters

[out] val Message index value to be returned.

Returns: Implementation dependent object accepted by "read" functions.

See also: comms::protocol::ProtocolLayerBase::read(); comms::protocol::ProtocolLayerBase::readFieldsCached()

◆ msgPayload()

template<typename TIter >

details::MsgPayloadRetriever< TIter > comms::protocol::msgPayload	(	TIter &	iter,
		std::size_t &	len
	)

Add "payload start" and "payload size" output parameters to protocol stack's (frame's) "read" operation.

Can be passed as variadic parameters to "read" functions of protocol stack (see comms::protocol::ProtocolLayerBase::read() and comms::protocol::ProtocolLayerBase::readFieldsCached()). It can be used to retrieve information on payload start location as well as its size.

using ProtocolStack = ...
ProtocolStack stack;
ProtocolStack::MsgPtr msg;
decltype(readIter) payloadIter;
std::size_t payloadSize = 0U;
auto es = stack.read(msg, readIter, size, comms::protocol::msgPayload(payloadIter, payloadSize));
... // use payload location and size information

Parameters

[out]	iter	Iterator pointing to the begining of the message payload in the input buffer.
[out]	len	Number of bytes in the detected payload.

Returns: Implementation dependent object accepted by "read" functions.

See also: comms::protocol::ProtocolLayerBase::read(); comms::protocol::ProtocolLayerBase::readFieldsCached()

Detailed Description

Namespaces

Classes

Functions

Function Documentation

◆ missingSize()

◆ msgId()

◆ msgIndex()

◆ msgPayload()