Detailed Description

An abstract interface for compressed readers.

Definition at line 109 of file reader.hpp.

#include <reader.hpp>

Inheritance diagram for mcap::ICompressedReader:

Public Member Functions
virtual	~ICompressedReader () override=default

virtual void	reset (const std::byte *data, uint64_t size, uint64_t uncompressedSize)=0
	Reset the reader state, clearing any internal buffers and state, and initialize with new compressed data.

virtual Status	status () const =0
	Report the current status of decompression. A StatusCode other than `StatusCode::Success` after `reset()` is called indicates the decompression was not successful and the reader is in an invalid state.

virtual uint64_t	size () const =0
	Returns the size of the file in bytes.

virtual uint64_t	read (std::byte **output, uint64_t offset, uint64_t size)=0
	This method is called by MCAP reader classes when they need to read a portion of the file.

Constructor & Destructor Documentation

◆ ~ICompressedReader()

virtual mcap::ICompressedReader::~ICompressedReader ( )

overridevirtualdefault

Member Function Documentation

◆ read()

virtual uint64_t mcap::IReadable::read	(	std::byte **	output,
		uint64_t	offset,
		uint64_t	size
	)

pure virtualinherited

This method is called by MCAP reader classes when they need to read a portion of the file.

Parameters

output	A pointer to a pointer to the buffer to write to. This method is expected to either maintain an internal buffer, read data into it, and update this pointer to point at the internal buffer, or update this pointer to point directly at the source data if possible. The pointer and data must remain valid and unmodified until the next call to read().
offset	The offset in bytes from the beginning of the file to read.
size	The number of bytes to read.

Returns: uint64_t Number of bytes actually read. This may be less than the requested size if the end of the file is reached. The output pointer must be readable from output to output + size. If the read fails, this method should return 0.

Implemented in mcap::FileReader, mcap::FileStreamReader, mcap::BufferReader, mcap::ZStdReader, and mcap::LZ4Reader.

◆ reset()

virtual void mcap::ICompressedReader::reset	(	const std::byte *	data,
		uint64_t	size,
		uint64_t	uncompressedSize
	)

pure virtual

Reset the reader state, clearing any internal buffers and state, and initialize with new compressed data.

Parameters

data	Compressed data to read from.
size	Size of the compressed data in bytes.
uncompressedSize	Size of the data in bytes after decompression. A buffer of this size will be allocated for the uncompressed data.

Implemented in mcap::BufferReader, mcap::ZStdReader, and mcap::LZ4Reader.

◆ size()

virtual uint64_t mcap::IReadable::size ( ) const

pure virtualinherited

Returns the size of the file in bytes.

Returns: uint64_t The total number of bytes in the MCAP file.

Implemented in mcap::FileReader, mcap::FileStreamReader, mcap::BufferReader, mcap::ZStdReader, and mcap::LZ4Reader.

◆ status()

virtual Status mcap::ICompressedReader::status ( ) const