Singleton class used to provide data compression and decompression in a variety of formats. More...

#include <Compressor.h>

Public Types
enum	CompressionType { UNCOMPRESSED = 0 , LZ4 , LZ4_BEST , GZIP }
	Enum of supported data compression types. More...

Static Public Member Functions
static Compressor &	getInstance ()
	Get an instance of this singleton class. More...

static CompressionType	toCompressionType (uint32_t type)
	Method to convert an integer to a CompressionType object. More...

static int	getMaxCompressedLength (CompressionType compressionType, uint32_t uncompressedLength)
	Returns the maximum number of bytes needed to compress the given length of uncompressed data. More...

static int	compressLZ4 (ByteBuffer &src, int srcSize, ByteBuffer &dst, int maxSize)
	Fastest LZ4 compression. More...

static int	compressLZ4 (uint8_t src, int srcOff, int srcSize, uint8_t dst, int dstOff, int maxSize)
	Fastest LZ4 compression. More...

static int	compressLZ4 (ByteBuffer &src, int srcOff, int srcSize, ByteBuffer &dst, int dstOff, int maxSize)
	Fastest LZ4 compression. More...

static int	compressLZ4Best (ByteBuffer &src, int srcSize, ByteBuffer &dst, int maxSize)
	Highest LZ4 compression. More...

static int	compressLZ4Best (uint8_t src, int srcOff, int srcSize, uint8_t dst, int dstOff, int maxSize)
	Highest LZ4 compression. More...

static int	compressLZ4Best (ByteBuffer &src, int srcOff, int srcSize, ByteBuffer &dst, int dstOff, int maxSize)
	Highest LZ4 compression. More...

static int	uncompressLZ4 (ByteBuffer &src, int srcSize, ByteBuffer &dst)
	LZ4 decompression. More...

static int	uncompressLZ4 (ByteBuffer &src, int srcOff, int srcSize, ByteBuffer &dst)
	LZ4 decompression. More...

static int	uncompressLZ4 (ByteBuffer &src, int srcOff, int srcSize, ByteBuffer &dst, int dstOff)
	LZ4 decompression. More...

static int	uncompressLZ4 (uint8_t src, int srcOff, int srcSize, uint8_t dst, int dstOff, int dstCapacity)
	LZ4 decompression. More...

Detailed Description

Singleton class used to provide data compression and decompression in a variety of formats.

This class in NOT thread safe when using the gzip deflating and inflating routines.

Date: 04/29/2019

Author: timmer

Member Enumeration Documentation

◆ CompressionType

enum evio::Compressor::CompressionType

Enum of supported data compression types.

Enumerator
UNCOMPRESSED
LZ4
LZ4_BEST
GZIP

Member Function Documentation

◆ compressLZ4() [1/3]

int evio::Compressor::compressLZ4	(	ByteBuffer &	src,
		int	srcOff,
		int	srcSize,
		ByteBuffer &	dst,
		int	dstOff,
		int	maxSize
	)

static

Fastest LZ4 compression.

Returns length of compressed data in bytes.

Parameters

src	source of uncompressed data.
srcOff	start offset in src regardless of position.
srcSize	number of bytes to compress.
dst	destination array.
dstOff	start offset in dst regardless of position.
maxSize	maximum number of bytes to write in dst.

Returns: length of compressed data in bytes.

Exceptions

EvioException if maxSize < max # of compressed bytes or compression failed.

References evio::ByteBuffer::array().

◆ compressLZ4() [2/3]

int evio::Compressor::compressLZ4	(	ByteBuffer &	src,
		int	srcSize,
		ByteBuffer &	dst,
		int	maxSize
	)

static

Fastest LZ4 compression.

Returns length of compressed data in bytes.

Parameters

src	source of uncompressed data from position.
srcSize	number of bytes to compress.
dst	destination buffer from position.
maxSize	maximum number of bytes to write in dst.

Returns: length of compressed data in bytes.

Exceptions

EvioException if maxSize < max # of compressed bytes or compression failed.

References evio::ByteBuffer::array(), and evio::ByteBuffer::position().

Referenced by evio::RecordOutput::build().

◆ compressLZ4() [3/3]

int evio::Compressor::compressLZ4	(	uint8_t *	src,
		int	srcOff,
		int	srcSize,
		uint8_t *	dst,
		int	dstOff,
		int	maxSize
	)

static

Fastest LZ4 compression.

Returns length of compressed data in bytes.

Parameters

src	source of uncompressed data.
srcOff	start offset in src.
srcSize	number of bytes to compress.
dst	destination array.
dstOff	start offset in dst.
maxSize	maximum number of bytes to write in dst.

Returns: length of compressed data in bytes.

Exceptions

EvioException if maxSize < max # of compressed bytes or compression failed.

◆ compressLZ4Best() [1/3]

int evio::Compressor::compressLZ4Best	(	ByteBuffer &	src,
		int	srcOff,
		int	srcSize,
		ByteBuffer &	dst,
		int	dstOff,
		int	maxSize
	)

static

Highest LZ4 compression.

Returns length of compressed data in bytes.

Parameters

src	source of uncompressed data.
srcOff	start offset in src.
srcSize	number of bytes to compress.
dst	destination array.
dstOff	start offset in dst.
maxSize	maximum number of bytes to write in dst.

Returns: length of compressed data in bytes.

Exceptions

EvioException if maxSize < max # of compressed bytes or compression failed.

References evio::ByteBuffer::array().

◆ compressLZ4Best() [2/3]

int evio::Compressor::compressLZ4Best	(	ByteBuffer &	src,
		int	srcSize,
		ByteBuffer &	dst,
		int	maxSize
	)

static

Highest LZ4 compression.

Returns length of compressed data in bytes.

Parameters

src	source of uncompressed data starting at position.
srcSize	number of bytes to compress.
dst	destination buffer starting at position.
maxSize	maximum number of bytes to write in dst.

Returns: length of compressed data in bytes.

Exceptions

EvioException if maxSize < max # of compressed bytes or compression failed.

References evio::ByteBuffer::array(), and evio::ByteBuffer::position().

Referenced by evio::RecordOutput::build().

◆ compressLZ4Best() [3/3]

int evio::Compressor::compressLZ4Best	(	uint8_t *	src,
		int	srcOff,
		int	srcSize,
		uint8_t *	dst,
		int	dstOff,
		int	maxSize
	)

static

Highest LZ4 compression.

Returns length of compressed data in bytes.

Parameters

src	source of uncompressed data.
srcOff	start offset in src.
srcSize	number of bytes to compress.
dst	destination array.
dstOff	start offset in dst.
maxSize	maximum number of bytes to write in dst.

Returns: length of compressed data in bytes.

Exceptions

EvioException if maxSize < max # of compressed bytes or compression failed.

◆ getInstance()

static Compressor& evio::Compressor::getInstance ( )

inlinestatic

Get an instance of this singleton class.

Returns: an instance of this singleton class.

Referenced by evio::RecordOutput::build(), evio::RecordInput::readRecord(), and evio::RecordInput::uncompressRecord().

◆ getMaxCompressedLength()

int evio::Compressor::getMaxCompressedLength	(	CompressionType	compressionType,
		uint32_t	uncompressedLength
	)

static

Returns the maximum number of bytes needed to compress the given length of uncompressed data.

Depends on compression type. Unknown for gzip.

Parameters

compressionType	type of data compression to do (0=none, 1=lz4 fast, 2=lz4 best, 3=gzip). Default to none.
uncompressedLength	uncompressed data length in bytes.

Returns: maximum compressed length in bytes or -1 if unknown.

References GZIP, LZ4, LZ4_BEST, and UNCOMPRESSED.

◆ toCompressionType()

Compressor::CompressionType evio::Compressor::toCompressionType ( uint32_t type )

static

Method to convert an integer to a CompressionType object.

Parameters

type	integer to convert.

Returns: corresponding CompressionType object.

References GZIP, LZ4, LZ4_BEST, and UNCOMPRESSED.

◆ uncompressLZ4() [1/4]

int evio::Compressor::uncompressLZ4	(	ByteBuffer &	src,
		int	srcOff,
		int	srcSize,
		ByteBuffer &	dst
	)

static

LZ4 decompression.

Returns original length of decompressed data in bytes.

Parameters

src	source of compressed data.
srcOff	start offset in src.
srcSize	number of compressed bytes.
dst	destination array.

Returns: original (uncompressed) input size.

Exceptions

EvioException if destination buffer is too small to hold uncompressed data or source data is malformed.

References evio::ByteBuffer::array(), evio::ByteBuffer::limit(), evio::ByteBuffer::position(), and evio::ByteBuffer::remaining().

◆ uncompressLZ4() [2/4]

int evio::Compressor::uncompressLZ4	(	ByteBuffer &	src,
		int	srcOff,
		int	srcSize,
		ByteBuffer &	dst,
		int	dstOff
	)

static

LZ4 decompression.

Returns original length of decompressed data in bytes.

Parameters

src	source of compressed data.
srcOff	start offset in src.
srcSize	number of compressed bytes.
dst	destination array.
dstOff	start offset in dst.

Returns: original (uncompressed) input size.

Exceptions

EvioException if destination buffer is too small to hold uncompressed data or source data is malformed.

References evio::ByteBuffer::array(), evio::ByteBuffer::limit(), and evio::ByteBuffer::remaining().

◆ uncompressLZ4() [3/4]

int evio::Compressor::uncompressLZ4	(	ByteBuffer &	src,
		int	srcSize,
		ByteBuffer &	dst
	)

static

LZ4 decompression.

Returns original length of decompressed data in bytes.

Parameters

src	source of compressed data.
srcSize	number of compressed bytes.
dst	destination array.

Returns: original (uncompressed) input size.

Exceptions

EvioException if destination buffer is too small to hold uncompressed data or source data is malformed.

References evio::ByteBuffer::position().

Referenced by evio::RecordInput::readRecord(), and evio::RecordInput::uncompressRecord().

◆ uncompressLZ4() [4/4]

int evio::Compressor::uncompressLZ4	(	uint8_t *	src,
		int	srcOff,
		int	srcSize,
		uint8_t *	dst,
		int	dstOff,
		int	dstCapacity
	)

static

LZ4 decompression.

Returns original length of decompressed data in bytes.

Parameters

src	source of compressed data.
srcOff	start offset in src.
srcSize	number of compressed bytes.
dst	destination array.
dstOff	start offset in dst.
dstCapacity	size of destination buffer in bytes, which must be already allocated.

Returns: original (uncompressed) input size.

Exceptions

EvioException if uncompressed data bytes > dstCapacity or source data is malformed.

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

Public Types

Static Public Member Functions

Detailed Description

Member Enumeration Documentation

◆ CompressionType

Member Function Documentation

◆ compressLZ4() [1/3]

◆ compressLZ4() [2/3]

◆ compressLZ4() [3/3]

◆ compressLZ4Best() [1/3]

◆ compressLZ4Best() [2/3]

◆ compressLZ4Best() [3/3]

◆ getInstance()

◆ getMaxCompressedLength()

◆ toCompressionType()

◆ uncompressLZ4() [1/4]

◆ uncompressLZ4() [2/4]

◆ uncompressLZ4() [3/4]

◆ uncompressLZ4() [4/4]