Provides a write interface to an MCAP file. More...

#include <writer.hpp>

Public Member Functions
void	addChannel (Channel &channel)
	Add a new channel to the MCAP file and set `channel.id` to a generated channel id. The channel id is used when adding messages to the file. More...

void	addSchema (Schema &schema)
	Add a new schema to the MCAP file and set `schema.id` to a generated schema id. The schema id is used when adding channels to the file. More...

void	close ()
	Write the MCAP footer, flush pending writes to the output stream, and reset internal state. More...

void	closeLastChunk ()
	finishes the current chunk in progress and writes it to the file, if a chunk is in progress. More...

IWritable *	dataSink ()
	Returns a pointer to the IWritable data destination backing this writer. Will return nullptr if the writer is not open. More...

void	open (IWritable &writer, const McapWriterOptions &options)
	Open a new MCAP file for writing and write the header. More...

void	open (std::ostream &stream, const McapWriterOptions &options)
	Open a new MCAP file for writing and write the header. More...

Status	open (std::string_view filename, const McapWriterOptions &options)
	Open a new MCAP file for writing and write the header. More...

const Statistics &	statistics () const
	Current MCAP file-level statistics. This is written as a Statistics record in the Summary section of the MCAP file. More...

void	terminate ()
	Reset internal state without writing the MCAP footer or flushing pending writes. This should only be used in error cases as the output MCAP file will be truncated. More...

Status	write (Attachment &attachment)
	Write an attachment to the output stream. More...

Status	write (const Message &message)
	Write a message to the output stream. More...

Status	write (const Metadata &metadata)
	Write a metadata record to the output stream. More...

	~McapWriter ()

Static Public Member Functions
static uint64_t	write (IWritable &output, const Attachment &attachment)

static uint64_t	write (IWritable &output, const AttachmentIndex &index)

static void	write (IWritable &output, const ByteArray bytes)

static uint64_t	write (IWritable &output, const Channel &channel)

static uint64_t	write (IWritable &output, const Chunk &chunk)

static uint64_t	write (IWritable &output, const ChunkIndex &index)

static uint64_t	write (IWritable &output, const DataEnd &dataEnd)

static uint64_t	write (IWritable &output, const Footer &footer, bool crcEnabled)

static uint64_t	write (IWritable &output, const Header &header)

static void	write (IWritable &output, const KeyValueMap &map, uint32_t size=0)

static uint64_t	write (IWritable &output, const Message &message)

static uint64_t	write (IWritable &output, const MessageIndex &index)

static uint64_t	write (IWritable &output, const Metadata &metadata)

static uint64_t	write (IWritable &output, const MetadataIndex &index)

static uint64_t	write (IWritable &output, const Record &record)

static uint64_t	write (IWritable &output, const Schema &schema)

static uint64_t	write (IWritable &output, const Statistics &stats)

static void	write (IWritable &output, const std::byte *data, uint64_t size)

static void	write (IWritable &output, const std::string_view str)

static uint64_t	write (IWritable &output, const SummaryOffset &summaryOffset)

static void	write (IWritable &output, OpCode value)

static void	write (IWritable &output, uint16_t value)

static void	write (IWritable &output, uint32_t value)

static void	write (IWritable &output, uint64_t value)

static void	writeMagic (IWritable &output)

Private Member Functions
IChunkWriter *	getChunkWriter ()

IWritable &	getOutput ()

void	writeChunk (IWritable &output, IChunkWriter &chunkData)

Private Attributes
std::vector< AttachmentIndex >	attachmentIndex_

std::vector< Channel >	channels_

std::vector< ChunkIndex >	chunkIndex_

uint64_t	chunkSize_ = DefaultChunkSize

Compression	compression_ = Compression::None

Timestamp	currentChunkEnd_ = 0

Timestamp	currentChunkStart_ = MaxTime

std::unordered_map< ChannelId, MessageIndex >	currentMessageIndex_

std::unique_ptr< FileWriter >	fileOutput_

std::unique_ptr< LZ4Writer >	lz4Chunk_

std::vector< MetadataIndex >	metadataIndex_

bool	opened_ = false

McapWriterOptions	options_ {""}

IWritable *	output_ = nullptr

std::vector< Schema >	schemas_

Statistics	statistics_ {}

std::unique_ptr< StreamWriter >	streamOutput_

std::unique_ptr< BufferWriter >	uncompressedChunk_

uint64_t	uncompressedSize_ = 0

std::unordered_set< SchemaId >	writtenSchemas_

std::unique_ptr< ZStdWriter >	zstdChunk_

Detailed Description

Provides a write interface to an MCAP file.

Definition at line 304 of file writer.hpp.

Constructor & Destructor Documentation

◆ ~McapWriter()

mcap::McapWriter::~McapWriter ( )

Member Function Documentation

◆ addChannel()

void mcap::McapWriter::addChannel ( Channel & channel )

Add a new channel to the MCAP file and set channel.id to a generated channel id. The channel id is used when adding messages to the file.

Parameters

channel Description of the channel to register. The id value is ignored and will be set to a generated channel id.

◆ addSchema()

void mcap::McapWriter::addSchema ( Schema & schema )

Add a new schema to the MCAP file and set schema.id to a generated schema id. The schema id is used when adding channels to the file.

Parameters

schema Description of the schema to register. The id field is ignored and will be set to a generated schema id.

◆ close()

void mcap::McapWriter::close ( )

Write the MCAP footer, flush pending writes to the output stream, and reset internal state.

◆ closeLastChunk()

void mcap::McapWriter::closeLastChunk ( )

finishes the current chunk in progress and writes it to the file, if a chunk is in progress.

◆ dataSink()

IWritable* mcap::McapWriter::dataSink ( )

Returns a pointer to the IWritable data destination backing this writer. Will return nullptr if the writer is not open.

◆ getChunkWriter()

IChunkWriter* mcap::McapWriter::getChunkWriter ( )

private

◆ getOutput()

IWritable& mcap::McapWriter::getOutput ( )

private

◆ open() [1/3]

void mcap::McapWriter::open	(	IWritable &	writer,
		const McapWriterOptions &	options
	)

Open a new MCAP file for writing and write the header.

Parameters

writer	An implementation of the IWritable interface. Output bytes will be written to this object.
options	Options for MCAP writing. `profile` is required.

◆ open() [2/3]

void mcap::McapWriter::open	(	std::ostream &	stream,
		const McapWriterOptions &	options
	)

Open a new MCAP file for writing and write the header.

Parameters

stream	Output stream to write to.
options	Options for MCAP writing. `profile` is required.

◆ open() [3/3]

Status mcap::McapWriter::open	(	std::string_view	filename,
		const McapWriterOptions &	options
	)

Open a new MCAP file for writing and write the header.

Parameters

filename	Filename of the MCAP file to write.
options	Options for MCAP writing. `profile` is required.

Returns: A non-success status if the file could not be opened for writing.

◆ statistics()

const Statistics& mcap::McapWriter::statistics ( ) const

Current MCAP file-level statistics. This is written as a Statistics record in the Summary section of the MCAP file.

◆ terminate()

void mcap::McapWriter::terminate ( )

Reset internal state without writing the MCAP footer or flushing pending writes. This should only be used in error cases as the output MCAP file will be truncated.

◆ write() [1/27]

Status mcap::McapWriter::write ( Attachment & attachment )

Write an attachment to the output stream.

Parameters

attachment Attachment to add. The attachment.crc will be calculated and set if configuration options allow CRC calculation.

Returns: A non-zero error code on failure.

◆ write() [2/27]

Status mcap::McapWriter::write ( const Message & message )

Write a message to the output stream.

Parameters

msg	Message to add.

Returns: A non-zero error code on failure.

◆ write() [3/27]

Status mcap::McapWriter::write ( const Metadata & metadata )

Write a metadata record to the output stream.

Parameters

metadata Named group of key/value string pairs to add.

Returns: A non-zero error code on failure.

◆ write() [4/27]

static uint64_t mcap::McapWriter::write	(	IWritable &	output,
		const Attachment &	attachment
	)

static

◆ write() [5/27]

static uint64_t mcap::McapWriter::write	(	IWritable &	output,
		const AttachmentIndex &	index
	)

static

◆ write() [6/27]

static void mcap::McapWriter::write	(	IWritable &	output,
		const ByteArray	bytes
	)

static

◆ write() [7/27]

static uint64_t mcap::McapWriter::write	(	IWritable &	output,
		const Channel &	channel
	)

static

◆ write() [8/27]

static uint64_t mcap::McapWriter::write	(	IWritable &	output,
		const Chunk &	chunk
	)

static

◆ write() [9/27]

static uint64_t mcap::McapWriter::write	(	IWritable &	output,
		const ChunkIndex &	index
	)

static

◆ write() [10/27]

static uint64_t mcap::McapWriter::write	(	IWritable &	output,
		const DataEnd &	dataEnd
	)

static

◆ write() [11/27]

static uint64_t mcap::McapWriter::write	(	IWritable &	output,
		const Footer &	footer,
		bool	crcEnabled
	)

static

◆ write() [12/27]

static uint64_t mcap::McapWriter::write	(	IWritable &	output,
		const Header &	header
	)

static

◆ write() [13/27]

static void mcap::McapWriter::write	(	IWritable &	output,
		const KeyValueMap &	map,
		uint32_t	size = `0`
	)

static

◆ write() [14/27]

static uint64_t mcap::McapWriter::write	(	IWritable &	output,
		const Message &	message
	)

static

◆ write() [15/27]

static uint64_t mcap::McapWriter::write	(	IWritable &	output,
		const MessageIndex &	index
	)

static

◆ write() [16/27]

static uint64_t mcap::McapWriter::write	(	IWritable &	output,
		const Metadata &	metadata
	)

static

◆ write() [17/27]

static uint64_t mcap::McapWriter::write	(	IWritable &	output,
		const MetadataIndex &	index
	)

static

◆ write() [18/27]

static uint64_t mcap::McapWriter::write	(	IWritable &	output,
		const Record &	record
	)

static

◆ write() [19/27]

static uint64_t mcap::McapWriter::write	(	IWritable &	output,
		const Schema &	schema
	)

static

◆ write() [20/27]

static uint64_t mcap::McapWriter::write	(	IWritable &	output,
		const Statistics &	stats
	)

static

◆ write() [21/27]

static void mcap::McapWriter::write	(	IWritable &	output,
		const std::byte *	data,
		uint64_t	size
	)

static

◆ write() [22/27]

static void mcap::McapWriter::write	(	IWritable &	output,
		const std::string_view	str
	)

static

◆ write() [23/27]

static uint64_t mcap::McapWriter::write	(	IWritable &	output,
		const SummaryOffset &	summaryOffset
	)

static

◆ write() [24/27]

static void mcap::McapWriter::write	(	IWritable &	output,
		OpCode	value
	)

static

◆ write() [25/27]

static void mcap::McapWriter::write	(	IWritable &	output,
		uint16_t	value
	)

static

◆ write() [26/27]

static void mcap::McapWriter::write	(	IWritable &	output,
		uint32_t	value
	)

static

◆ write() [27/27]

static void mcap::McapWriter::write	(	IWritable &	output,
		uint64_t	value
	)

static

◆ writeChunk()

void mcap::McapWriter::writeChunk	(	IWritable &	output,
		IChunkWriter &	chunkData
	)

private

◆ writeMagic()

static void mcap::McapWriter::writeMagic ( IWritable & output )

static

Member Data Documentation

◆ attachmentIndex_

std::vector<AttachmentIndex> mcap::McapWriter::attachmentIndex_

private

Definition at line 452 of file writer.hpp.

◆ channels_

std::vector<Channel> mcap::McapWriter::channels_

private

Definition at line 451 of file writer.hpp.

◆ chunkIndex_

std::vector<ChunkIndex> mcap::McapWriter::chunkIndex_

private

Definition at line 454 of file writer.hpp.

◆ chunkSize_

uint64_t mcap::McapWriter::chunkSize_ = DefaultChunkSize

private

Definition at line 443 of file writer.hpp.

◆ compression_

Compression mcap::McapWriter::compression_ = Compression::None

private

Definition at line 460 of file writer.hpp.

◆ currentChunkEnd_

Timestamp mcap::McapWriter::currentChunkEnd_ = 0

private

Definition at line 459 of file writer.hpp.

◆ currentChunkStart_

Timestamp mcap::McapWriter::currentChunkStart_ = MaxTime

private

Definition at line 458 of file writer.hpp.

◆ currentMessageIndex_

std::unordered_map<ChannelId, MessageIndex> mcap::McapWriter::currentMessageIndex_

private

Definition at line 457 of file writer.hpp.

◆ fileOutput_

std::unique_ptr<FileWriter> mcap::McapWriter::fileOutput_

private

Definition at line 445 of file writer.hpp.

◆ lz4Chunk_

std::unique_ptr<LZ4Writer> mcap::McapWriter::lz4Chunk_

private

Definition at line 448 of file writer.hpp.

◆ metadataIndex_

std::vector<MetadataIndex> mcap::McapWriter::metadataIndex_

private

Definition at line 453 of file writer.hpp.

◆ opened_

bool mcap::McapWriter::opened_ = false

private

Definition at line 462 of file writer.hpp.

◆ options_

McapWriterOptions mcap::McapWriter::options_ {""}

private

Definition at line 442 of file writer.hpp.

◆ output_

IWritable* mcap::McapWriter::output_ = nullptr

private

Definition at line 444 of file writer.hpp.

◆ schemas_

std::vector<Schema> mcap::McapWriter::schemas_

private

Definition at line 450 of file writer.hpp.

◆ statistics_

Statistics mcap::McapWriter::statistics_ {}

private

Definition at line 455 of file writer.hpp.

◆ streamOutput_

std::unique_ptr<StreamWriter> mcap::McapWriter::streamOutput_

private

Definition at line 446 of file writer.hpp.

◆ uncompressedChunk_

std::unique_ptr<BufferWriter> mcap::McapWriter::uncompressedChunk_

private

Definition at line 447 of file writer.hpp.

◆ uncompressedSize_

uint64_t mcap::McapWriter::uncompressedSize_ = 0

private

Definition at line 461 of file writer.hpp.

◆ writtenSchemas_

std::unordered_set<SchemaId> mcap::McapWriter::writtenSchemas_

private

Definition at line 456 of file writer.hpp.

◆ zstdChunk_

std::unique_ptr<ZStdWriter> mcap::McapWriter::zstdChunk_

private

Definition at line 449 of file writer.hpp.

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

writer.hpp

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ ~McapWriter()

Member Function Documentation

◆ addChannel()

◆ addSchema()

◆ close()

◆ closeLastChunk()

◆ dataSink()

◆ getChunkWriter()

◆ getOutput()

◆ open() [1/3]

◆ open() [2/3]

◆ open() [3/3]

◆ statistics()

◆ terminate()

◆ write() [1/27]

◆ write() [2/27]

◆ write() [3/27]

◆ write() [4/27]

◆ write() [5/27]

◆ write() [6/27]

◆ write() [7/27]

◆ write() [8/27]

◆ write() [9/27]

◆ write() [10/27]

◆ write() [11/27]

◆ write() [12/27]

◆ write() [13/27]

◆ write() [14/27]

◆ write() [15/27]

◆ write() [16/27]

◆ write() [17/27]

◆ write() [18/27]

◆ write() [19/27]

◆ write() [20/27]

◆ write() [21/27]

◆ write() [22/27]

◆ write() [23/27]

◆ write() [24/27]

◆ write() [25/27]

◆ write() [26/27]

◆ write() [27/27]

◆ writeChunk()

◆ writeMagic()

Member Data Documentation

◆ attachmentIndex_

◆ channels_

◆ chunkIndex_

◆ chunkSize_

◆ compression_

◆ currentChunkEnd_

◆ currentChunkStart_

◆ currentMessageIndex_

◆ fileOutput_

◆ lz4Chunk_

◆ metadataIndex_

◆ opened_

◆ options_

◆ output_

◆ schemas_

◆ statistics_

◆ streamOutput_

◆ uncompressedChunk_

◆ uncompressedSize_

◆ writtenSchemas_

◆ zstdChunk_