mcap::ZStdReader Class Reference

ICompressedReader implementation that decompresses Zstandard (https://facebook.github.io/zstd/) data. More...

#include <reader.hpp>

Inheritance diagram for mcap::ZStdReader:

Public Member Functions
ZStdReader &	operator= (const ZStdReader &)=delete
ZStdReader &	operator= (ZStdReader &&)=delete
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. More...
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. More...
uint64_t	size () const override
	Returns the size of the file in bytes. More...
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. More...
	ZStdReader ()=default
	ZStdReader (const ZStdReader &)=delete
	ZStdReader (ZStdReader &&)=delete
Public Member Functions inherited from mcap::ICompressedReader
virtual	~ICompressedReader () override=default
Public Member Functions inherited from mcap::IReadable
virtual	~IReadable ()=default

Static Public Member Functions
static Status	DecompressAll (const std::byte *data, uint64_t compressedSize, uint64_t uncompressedSize, ByteArray *output)
	Decompresses an entire Zstd-compressed chunk into output. More...

Private Attributes
Status	status_
ByteArray	uncompressedData_

Detailed Description

ICompressedReader implementation that decompresses Zstandard (https://facebook.github.io/zstd/) data.

Definition at line 157 of file reader.hpp.

Constructor & Destructor Documentation

ZStdReader() [1/3]

mcap::ZStdReader::ZStdReader ( )

default

ZStdReader() [2/3]

mcap::ZStdReader::ZStdReader ( const ZStdReader &  )

delete

ZStdReader() [3/3]

mcap::ZStdReader::ZStdReader ( ZStdReader &&  )

delete

Member Function Documentation

DecompressAll()

static Status mcap::ZStdReader::DecompressAll ( const std::byte *  data, uint64_t  compressedSize, uint64_t  uncompressedSize, ByteArray *  output  )

static

Decompresses an entire Zstd-compressed chunk into output.

Parameters

data	The Zstd-compressed input chunk.
compressedSize	The size of the Zstd-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

operator=() [1/2]

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

delete

operator=() [2/2]

ZStdReader& mcap::ZStdReader::operator= ( ZStdReader &&  )

delete

read()

uint64_t mcap::ZStdReader::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.

reset()

void mcap::ZStdReader::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.

size()

uint64_t mcap::ZStdReader::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.

status()

Status mcap::ZStdReader::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.

Member Data Documentation

status_

Status mcap::ZStdReader::status_

private

Definition at line 183 of file reader.hpp.

uncompressedData_

ByteArray mcap::ZStdReader::uncompressedData_

private

Definition at line 184 of file reader.hpp.

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

• reader.hpp