SctArchiving::ZlibStringCompressor Class Reference

Uses zlib to compress a string into another (hopefully shorter!) string. More...

#include <ZlibStringCompressor.h>

Public Member Functions
	ZlibStringCompressor (unsigned long bufferSize=0)
	constructor, with optional bufferSizeArgument;
const string	compress (const string &toCompress, int level)
	Compress a string.
const string	inflate (const string &compressed)
	Uncompress a string.
unsigned long	getBufferSize ()
	Find the size of the buffer in bytes (for information);.
void	setDebugLevel (int level)
	Level of 0 produces no output.
int	getDebugLevel ()
	return the value of the debug level.
Bytef *	setBufferSize (unsigned long size)
	set the buffer size (in bytes)
Static Private Member Functions
static void	checkZlibResult (const int result, const char *file, const int line)
	Check return result number from zlib, throwing InvalidArgument if necessary.
static unsigned long	findSizeInBytes (const string &s)
	Find the length in bytes of a string.
static unsigned long	findRequiredBufferSize (const unsigned long uncompressedSize)
	Find the minimum buffer size for compresses string.
Private Attributes
long unsigned	m_bufferSize
	size in bytes of the buffer
Bytef *	m_buffer
int	m_debugLevel

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Detailed Description

Uses zlib to compress a string into another (hopefully shorter!) string.

Can also extract a compressed string. The extraction step requires a buffer, so the class has an interal buffer, which it increases in size if necessary, to fit the uncompressed string. Sends mrs messages if it encounters problems with zlib. Designed so that a single instance of this class should be re-used many times, so clients should initiate one and then continue to re-use it for best use of the buffering. Note that returned `strings' are actually references to data held in internal buffers.

Note:

the buffer size required for extraction cannot be known in advanced. So the buffer can dynamically increase its size, to allow for bigger `original sized' strings.

Definition at line 22 of file ZlibStringCompressor.h.

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Constructor & Destructor Documentation

SctArchiving::ZlibStringCompressor::ZlibStringCompressor (  unsigned long  bufferSize = 0  )

constructor, with optional bufferSizeArgument; Definition at line 12 of file ZlibStringCompressor.cpp. References setBufferSize(). Here is the call graph for this function:

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Member Function Documentation

void SctArchiving::ZlibStringCompressor::checkZlibResult (  const int  result, const char *  file, const int  line )  [static, private]

Check return result number from zlib, throwing InvalidArgument if necessary. Definition at line 35 of file ZlibStringCompressor.cpp. Referenced by compress(), and inflate().

const string SctArchiving::ZlibStringCompressor::compress (  const string &  toCompress, int  level )

Compress a string. Parameters: reference  to string to compress gzip  compression level 1->9; Returns: compressed string (actual string is stored in buffer.) Definition at line 50 of file ZlibStringCompressor.cpp. References checkZlibResult(), findRequiredBufferSize(), findSizeInBytes(), getBufferSize(), m_buffer, and setBufferSize(). Here is the call graph for this function:

static unsigned long SctArchiving::ZlibStringCompressor::findRequiredBufferSize (  const unsigned long  uncompressedSize  )  [static, private]

Find the minimum buffer size for compresses string. Parameters: uncompressed  size Referenced by compress().

unsigned long SctArchiving::ZlibStringCompressor::findSizeInBytes (  const string &  s  )  [inline, static, private]

Find the length in bytes of a string. Definition at line 83 of file ZlibStringCompressor.h. Referenced by compress(), and inflate().

unsigned long SctArchiving::ZlibStringCompressor::getBufferSize (   )

Find the size of the buffer in bytes (for information);. Definition at line 17 of file ZlibStringCompressor.cpp. References m_bufferSize. Referenced by compress(), and inflate().

int SctArchiving::ZlibStringCompressor::getDebugLevel (   )  [inline]

return the value of the debug level. Definition at line 96 of file ZlibStringCompressor.h. References m_debugLevel. Referenced by setBufferSize().

const string SctArchiving::ZlibStringCompressor::inflate (  const string &  compressed  )

Uncompress a string. Parameters: reference  to compressed string. Returns: uncompressed equivalent (actual string is stored in buffer.) Definition at line 76 of file ZlibStringCompressor.cpp. References checkZlibResult(), findSizeInBytes(), getBufferSize(), m_buffer, and setBufferSize(). Here is the call graph for this function:

Bytef * SctArchiving::ZlibStringCompressor::setBufferSize (  unsigned long  size  )

set the buffer size (in bytes) Definition at line 21 of file ZlibStringCompressor.cpp. References getDebugLevel(), m_buffer, and m_bufferSize. Referenced by compress(), inflate(), and ZlibStringCompressor(). Here is the call graph for this function:

void SctArchiving::ZlibStringCompressor::setDebugLevel (  int  level  )  [inline]

Level of 0 produces no output. Higher levels produce more output. Definition at line 92 of file ZlibStringCompressor.h. References m_debugLevel.

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Field Documentation

long unsigned SctArchiving::ZlibStringCompressor::m_bufferSize [private]

size in bytes of the buffer Definition at line 65 of file ZlibStringCompressor.h. Referenced by getBufferSize(), and setBufferSize().

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

• ZlibStringCompressor.h
• ZlibStringCompressor.cpp

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