mcap::IndexedMessageReader Struct Reference

Detailed Description

Uses message indices to read messages out of an MCAP in log time order. The underlying MCAP must be chunked, with a summary section and message indexes. The required McapWriterOptions are:

• noChunking: false
• noMessageIndex: false
• noSummary: false

Definition at line 611 of file reader.hpp.

#include <reader.hpp>

Classes
struct	ChunkSlot

Public Member Functions
	IndexedMessageReader (McapReader &reader, const ReadMessageOptions &options, const std::function< void(const Message &, RecordOffset)> onMessage)
bool	next ()
	reads the next message out of the MCAP.
Status	status () const
	gets the status of the reader.

Private Member Functions
size_t	findFreeChunkSlot ()
void	decompressChunk (const Chunk &chunk, ChunkSlot &slot)

Private Attributes
Status	status_
McapReader &	mcapReader_
RecordReader	recordReader_
LZ4Reader	lz4Reader_
ReadMessageOptions	options_
std::unordered_set< ChannelId >	selectedChannels_
std::function< void(const Message &, RecordOffset)>	onMessage_
internal::ReadJobQueue	queue_
std::vector< ChunkSlot >	chunkSlots_

Constructor & Destructor Documentation

IndexedMessageReader()

mcap::IndexedMessageReader::IndexedMessageReader	(	McapReader &	reader,
		const ReadMessageOptions &	options,
		const std::function< void(const Message &, RecordOffset)>	onMessage
	)

Definition at line 1800 of file reader.inl.

Member Function Documentation

decompressChunk()

void mcap::IndexedMessageReader::decompressChunk ( const Chunk &  chunk, IndexedMessageReader::ChunkSlot &  slot  )

private

Definition at line 1864 of file reader.inl.

findFreeChunkSlot()

size_t mcap::IndexedMessageReader::findFreeChunkSlot ( )

private

Definition at line 1854 of file reader.inl.

next()

bool mcap::IndexedMessageReader::next

(

)

reads the next message out of the MCAP.

Returns

true if a message was found.

false if no more messages are to be read. If there was some error reading the MCAP, status() will return a non-Success status.

Definition at line 1895 of file reader.inl.

status()

Status mcap::IndexedMessageReader::status

(

)

const

gets the status of the reader.

Returns

Status

Definition at line 1985 of file reader.inl.

Member Data Documentation

chunkSlots_

std::vector<ChunkSlot> mcap::IndexedMessageReader::chunkSlots_

private

Definition at line 650 of file reader.hpp.

lz4Reader_

LZ4Reader mcap::IndexedMessageReader::lz4Reader_

private

Definition at line 644 of file reader.hpp.

mcapReader_

McapReader& mcap::IndexedMessageReader::mcapReader_

private

Definition at line 641 of file reader.hpp.

onMessage_

std::function<void(const Message&, RecordOffset)> mcap::IndexedMessageReader::onMessage_

private

Definition at line 648 of file reader.hpp.

options_

ReadMessageOptions mcap::IndexedMessageReader::options_

private

Definition at line 646 of file reader.hpp.

queue_

internal::ReadJobQueue mcap::IndexedMessageReader::queue_

private

Definition at line 649 of file reader.hpp.

recordReader_

RecordReader mcap::IndexedMessageReader::recordReader_

private

Definition at line 642 of file reader.hpp.

selectedChannels_

std::unordered_set<ChannelId> mcap::IndexedMessageReader::selectedChannels_

private

Definition at line 647 of file reader.hpp.

status_

Status mcap::IndexedMessageReader::status_

private

Definition at line 640 of file reader.hpp.

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The documentation for this struct was generated from the following files:

• reader.hpp
• reader.inl