point_one::fusion_engine::parsers::FusionEngineFramer Class Reference

Frame and validate incoming FusionEngine messages. More...

#include <point_one/fusion_engine/parsers/fusion_engine_framer.h>

Public Member Functions

 FusionEngineFramer ()=default
 Construct a framer instance with no buffer allocated. More...
 
 FusionEngineFramer (size_t capacity_bytes)
 Construct a framer instance with an internally allocated buffer. More...
 
 FusionEngineFramer (void *buffer, size_t capacity_bytes)
 Construct a framer instance with a user-specified buffer. More...
 
size_t OnData (const uint8_t *buffer, size_t length_bytes)
 Process incoming data. More...
 
void Reset ()
 Reset the framer and discard all pending data. More...
 
void SetBuffer (void *buffer, size_t capacity_bytes)
 Set the buffer to use for message framing. More...
 
void SetMessageCallback (std::function< void(const messages::MessageHeader &, const void *)> callback)
 Specify a function to be called when a message is framed. More...
 
void WarnOnError (bool enabled)
 Enable/disable warnings for CRC and "message too large" failures. More...
 

Private Types

enum  State { State::SYNC0 = 0, State::SYNC1 = 1, State::HEADER = 2, State::DATA = 3 }
 

Private Member Functions

int32_t OnByte (bool quiet)
 Process a single byte. More...
 
uint32_t Resync ()
 Perform a resynchronization operation starting at buffer_[1]. More...
 

Private Attributes

uint8_t * buffer_ {nullptr}
 
std::function< void(const messages::MessageHeader &, const void *)> callback_
 
uint32_t capacity_bytes_ {0}
 
uint32_t current_message_size_ {0}
 
std::unique_ptr< uint8_t[]> managed_buffer_
 
uint32_t next_byte_index_ {0}
 
State state_ {State::SYNC0}
 
bool warn_on_error_ = true
 

Detailed Description

Frame and validate incoming FusionEngine messages.

This class locates and validates FusionEngine messages within a stream of binary data. Data may be stored in an internally allocated buffer, or in an external buffer supplied by the user.

The callback function provided to SetMessageCallback() will be called each time a complete message is received. Any messages that do not pass the CRC check, or that are too big to be stored in the data buffer, will be discarded.

Example usage:

void MessageReceived(const MessageHeader& header, const void* payload) {
if (header.message_type == MessageType::POSE) {
auto& contents = *static_cast<const PoseMessage*>(payload);
...
}
}
FusionEngineFramer framer(1024);
framer.SetMessageCallback(MessageReceived);
framer.OnData(my_data, my_data_size);

Definition at line 45 of file fusion_engine_framer.h.

Member Enumeration Documentation

◆ State

Enumerator
SYNC0 
SYNC1 
HEADER 
DATA 

Definition at line 129 of file fusion_engine_framer.h.

Constructor & Destructor Documentation

◆ FusionEngineFramer() [1/3]

point_one::fusion_engine::parsers::FusionEngineFramer::FusionEngineFramer ( )
default

Construct a framer instance with no buffer allocated.

Note
You must call SetBuffer() to assign a buffer, otherwise all incoming data will be discarded.

◆ FusionEngineFramer() [2/3]

point_one::fusion_engine::parsers::FusionEngineFramer::FusionEngineFramer ( size_t  capacity_bytes)
inlineexplicit

Construct a framer instance with an internally allocated buffer.

Parameters
capacity_bytesThe maximum framing buffer capacity (in bytes).

Definition at line 61 of file fusion_engine_framer.h.

◆ FusionEngineFramer() [3/3]

FusionEngineFramer::FusionEngineFramer ( void *  buffer,
size_t  capacity_bytes 
)

Construct a framer instance with a user-specified buffer.

Postcondition
buffer must exist for the lifetime of this instance.
Parameters
bufferThe framing buffer to use. Set to nullptr to allocate a buffer internally.
capacity_bytesThe maximum framing buffer capacity (in bytes).

Definition at line 41 of file fusion_engine_framer.cc.

Member Function Documentation

◆ OnByte()

int32_t FusionEngineFramer::OnByte ( bool  quiet)
private

Process a single byte.

Precondition
The byte must be located at buffer_[next_byte_index_ - 1].
Parameters
quietIf true, suppress failure warning messages.
Returns
The total size of all valid, complete messages, 0 if no messages were completed, or <0 CRC or "message too large" error.

Definition at line 139 of file fusion_engine_framer.cc.

◆ OnData()

size_t FusionEngineFramer::OnData ( const uint8_t *  buffer,
size_t  length_bytes 
)

Process incoming data.

Parameters
bufferA buffer containing data to be framed.
length_bytesThe number of bytes to be framed.
Returns
The total size of all valid, complete messages, or 0 if no messages were completed.

Definition at line 99 of file fusion_engine_framer.cc.

◆ Reset()

void FusionEngineFramer::Reset ( )

Reset the framer and discard all pending data.

Definition at line 92 of file fusion_engine_framer.cc.

◆ Resync()

uint32_t FusionEngineFramer::Resync ( )
private

Perform a resynchronization operation starting at buffer_[1].

Returns
The total size of all valid, complete messages, or 0 if no messages were completed.

Definition at line 315 of file fusion_engine_framer.cc.

◆ SetBuffer()

void FusionEngineFramer::SetBuffer ( void *  buffer,
size_t  capacity_bytes 
)

Set the buffer to use for message framing.

Postcondition
buffer must exist for the lifetime of this instance.
Parameters
bufferThe framing buffer to use. Set to nullptr to allocate a buffer internally.
capacity_bytesThe maximum framing buffer capacity (in bytes).

Definition at line 55 of file fusion_engine_framer.cc.

◆ SetMessageCallback()

void point_one::fusion_engine::parsers::FusionEngineFramer::SetMessageCallback ( std::function< void(const messages::MessageHeader &, const void *)>  callback)
inline

Specify a function to be called when a message is framed.

Parameters
callbackThe function to be called with the message header and a pointer to the message payload.

Definition at line 106 of file fusion_engine_framer.h.

◆ WarnOnError()

void point_one::fusion_engine::parsers::FusionEngineFramer::WarnOnError ( bool  enabled)
inline

Enable/disable warnings for CRC and "message too large" failures.

This is typically used when the incoming stream has multiple types of binary content (e.g., interleaved FusionEngine and RTCM messages), and the FusionEngine message preamble is expected to appear in the non-FusionEngine content occasionally.

Parameters
enabledIf true, issue warnings on errors.

Definition at line 98 of file fusion_engine_framer.h.

Member Data Documentation

◆ buffer_

uint8_t* point_one::fusion_engine::parsers::FusionEngineFramer::buffer_ {nullptr}
private

Definition at line 141 of file fusion_engine_framer.h.

◆ callback_

std::function<void(const messages::MessageHeader&, const void*)> point_one::fusion_engine::parsers::FusionEngineFramer::callback_
private

Definition at line 136 of file fusion_engine_framer.h.

◆ capacity_bytes_

uint32_t point_one::fusion_engine::parsers::FusionEngineFramer::capacity_bytes_ {0}
private

Definition at line 142 of file fusion_engine_framer.h.

◆ current_message_size_

uint32_t point_one::fusion_engine::parsers::FusionEngineFramer::current_message_size_ {0}
private

Definition at line 146 of file fusion_engine_framer.h.

◆ managed_buffer_

std::unique_ptr<uint8_t[]> point_one::fusion_engine::parsers::FusionEngineFramer::managed_buffer_
private

Definition at line 140 of file fusion_engine_framer.h.

◆ next_byte_index_

uint32_t point_one::fusion_engine::parsers::FusionEngineFramer::next_byte_index_ {0}
private

Definition at line 145 of file fusion_engine_framer.h.

◆ state_

State point_one::fusion_engine::parsers::FusionEngineFramer::state_ {State::SYNC0}
private

Definition at line 144 of file fusion_engine_framer.h.

◆ warn_on_error_

bool point_one::fusion_engine::parsers::FusionEngineFramer::warn_on_error_ = true
private

Definition at line 138 of file fusion_engine_framer.h.


The documentation for this class was generated from the following files:
FusionEngineFramer()=default
Construct a framer instance with no buffer allocated.