mcap::LZ4Reader Class Reference

Detailed Description

ICompressedReader implementation that decompresses LZ4 (https://lz4.github.io/lz4/) data.

Definition at line 194 of file reader.hpp.

#include <reader.hpp>

Inheritance diagram for mcap::LZ4Reader:

Public Member Functions
void	reset (const std::byte *data, uint64_t size, uint64_t uncompressedSize) override
	Reset the reader state, clearing any internal buffers and state, and initialize with new compressed data.
uint64_t	read (std::byte **output, uint64_t offset, uint64_t size) override
	This method is called by MCAP reader classes when they need to read a portion of the file.
uint64_t	size () const override
	Returns the size of the file in bytes.
Status	status () const override
	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.
Status	decompressAll (const std::byte *data, uint64_t size, uint64_t uncompressedSize, ByteArray *output)
	Decompresses an entire LZ4-encoded chunk into output.
	LZ4Reader ()
	LZ4Reader (const LZ4Reader &)=delete
LZ4Reader &	operator= (const LZ4Reader &)=delete
	LZ4Reader (LZ4Reader &&)=delete
LZ4Reader &	operator= (LZ4Reader &&)=delete
	~LZ4Reader () override

Private Attributes
void *	decompressionContext_ = nullptr
Status	status_
const std::byte *	compressedData_
ByteArray	uncompressedData_
uint64_t	compressedSize_
uint64_t	uncompressedSize_

Constructor & Destructor Documentation

LZ4Reader() [1/3]

mcap::LZ4Reader::LZ4Reader

(

)

Definition at line 127 of file reader.inl.

LZ4Reader() [2/3]

mcap::LZ4Reader::LZ4Reader ( const LZ4Reader &  )

delete

LZ4Reader() [3/3]

mcap::LZ4Reader::LZ4Reader ( LZ4Reader &&  )

delete

~LZ4Reader()

mcap::LZ4Reader::~LZ4Reader ( )

override

Definition at line 138 of file reader.inl.

Member Function Documentation

decompressAll()

Status mcap::LZ4Reader::decompressAll	(	const std::byte *	data,
		uint64_t	size,
		uint64_t	uncompressedSize,
		ByteArray *	output
	)

Decompresses an entire LZ4-encoded chunk into output.

Parameters

data	The LZ4-compressed input chunk.
size	The size of the LZ4-compressed input.
uncompressedSize	The size of the data once uncompressed.
output	The output vector. This will be resized to uncompressedSize to fit the data, or 0 if the decompression encountered an error.

Returns

Status

Definition at line 171 of file reader.inl.

operator=() [1/2]

LZ4Reader & mcap::LZ4Reader::operator= ( const LZ4Reader &  )

delete

operator=() [2/2]

LZ4Reader & mcap::LZ4Reader::operator= ( LZ4Reader &&  )

delete

read()

uint64_t mcap::LZ4Reader::read ( std::byte **  output, uint64_t  offset, uint64_t  size  )

overridevirtual

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.

Implements mcap::IReadable.

Definition at line 154 of file reader.inl.

reset()

void mcap::LZ4Reader::reset ( const std::byte *  data, uint64_t  size, uint64_t  uncompressedSize  )

overridevirtual

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.

Implements mcap::ICompressedReader.

Definition at line 144 of file reader.inl.

size()

uint64_t mcap::LZ4Reader::size ( ) const

overridevirtual

Returns the size of the file in bytes.

Returns

uint64_t The total number of bytes in the MCAP file.

Implements mcap::IReadable.

Definition at line 164 of file reader.inl.

status()

Status mcap::LZ4Reader::status ( ) const

overridevirtual

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.

Implements mcap::ICompressedReader.

Definition at line 168 of file reader.inl.

Member Data Documentation

compressedData_

const std::byte* mcap::LZ4Reader::compressedData_

private

Definition at line 223 of file reader.hpp.

compressedSize_

uint64_t mcap::LZ4Reader::compressedSize_

private

Definition at line 225 of file reader.hpp.

decompressionContext_

void* mcap::LZ4Reader::decompressionContext_ = nullptr

private

Definition at line 221 of file reader.hpp.

status_

Status mcap::LZ4Reader::status_

private

Definition at line 222 of file reader.hpp.

uncompressedData_

ByteArray mcap::LZ4Reader::uncompressedData_

private

Definition at line 224 of file reader.hpp.

uncompressedSize_

uint64_t mcap::LZ4Reader::uncompressedSize_

private

Definition at line 226 of file reader.hpp.

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

• reader.hpp
• reader.inl