#include <ZipCompressor.h>

Inheritance diagram for CZipCompressor:

Classes
class	COffsetsArray

struct	COffsetsPair

struct	COptions

class	COptionsMap

Public Types
enum	CompressionLevel { levelDefault = -1, levelStore = 0, levelFastest = 1, levelBest = 9 }

enum	CompressionMethod { methodStore = 0, methodDeflate = 8, methodBzip2 = 12, methodWinZipAes = 99 }

enum	CompressorType { typeDeflate = 1, typeBzip2, typePPMd }

typedef CZipArray< COffsetsPair * >	CZipOffsetsPairsArray

Public Member Functions
virtual bool	CanProcess (WORD uMethod)=0

virtual void	Compress (const void *pBuffer, DWORD uSize)=0

virtual DWORD	Decompress (void *pBuffer, DWORD uSize)=0

virtual void	FinishCompression (bool bAfterException)

virtual void	FinishDecompression (bool bAfterException)

virtual const COptions *	GetOptions () const

virtual void	InitCompression (int iLevel, CZipFileHeader pFile, CZipCryptograph pCryptograph)

virtual void	InitDecompression (CZipFileHeader pFile, CZipCryptograph pCryptograph)

bool	PrepareForSeek (CZipFileHeader pCurrentFile, COffsetsPair pPair)

void	UpdateOptions (const COptionsMap &optionsMap)

Static Public Member Functions
static CZipCompressor *	CreateCompressor (WORD uMethod, CZipStorage *pStorage)

static bool	IsCompressionSupported (WORD uCompressionMethod)

Public Attributes
ZIP_SIZE_TYPE	m_uComprLeft
	The number of bytes left to compress.

DWORD	m_uCrc32
	The CRC32 file checksum.

ZIP_SIZE_TYPE	m_uUncomprLeft
	The number of bytes left to decompress.

Protected Member Functions
virtual int	ConvertInternalError (int iErr) const

	CZipCompressor (CZipStorage *pStorage)

DWORD	FillBuffer ()

void	FlushWriteBuffer ()

void	InitBuffer ()

void	ReleaseBuffer ()

void	ThrowError (int iErr, bool bInternal=false)

void	UpdateCrc (const void *pBuffer, DWORD uSize)

void	UpdateFileCrc (const void *pBuffer, DWORD uSize)

virtual void	UpdateOptions (const COptions *pOptions)

void	WriteBuffer (char *pBuffer, DWORD uSize)

Protected Attributes
CZipAutoBuffer	m_pBuffer
	A buffer that receives compressed data or provides data for decompression.

CZipCryptograph *	m_pCryptograph
	The current cryptograph.

CZipFileHeader *	m_pFile
	The file header being compressed or decompressed.

CZipStorage *	m_pStorage
	The current storage object.

Detailed Description

A base class for compressors used in compression and decompression of data.

Member Enumeration Documentation

enum CZipCompressor::CompressionLevel

The compression level.

Enumerator:

levelDefault	The default compression level (equals `6` for deflate).
levelStore	No compression used. Data is stored.
levelFastest	The fastest compression. The compression ratio is the lowest (apart from levelStore).
levelBest	The highest compression ratio. It's usually the slowest one.

enum CZipCompressor::CompressionMethod

The compression method.

Enumerator:

methodStore	A file is stored, not compressed.
methodDeflate	The deflate compression method.
methodBzip2	The bzip2 compression method. See Also Compressing Data
methodWinZipAes	This value means that WinZip AES encryption is used. The original compression method is stored in a WinZip extra field. It is only an informational value - you cannot set it as a compression method. The ZipArchive Library handles this value internally. See Also Encryption Methods: How to Best Protect Your Data

enum CZipCompressor::CompressorType

The type of a compressor.

Enumerator:

typeDeflate	Deflate compression (default in zip archives).
typeBzip2	Bzip2 compression.
typePPMd	PPMd compression.

Constructor & Destructor Documentation

CZipCompressor::CZipCompressor ( CZipStorage * pStorage )

inlineprotected

Initializes a new instance of the CZipCompressor class.

Parameters

pStorage The current storage object.

Member Function Documentation

virtual bool CZipCompressor::CanProcess ( WORD uMethod )

pure virtual

Returns the value indicating whether the current CZipCompressor object supports the given compression method.

Parameters

uMethod The compression method. It can be one of the CompressionMethod values.

Returns: true, if the compression method is supported; false otherwise.

Implemented in ZipArchiveLib::CDeflateCompressor, and ZipArchiveLib::CBzip2Compressor.

virtual void CZipCompressor::Compress	(	const void *	pBuffer,
		DWORD	uSize
	)

pure virtual

Compresses the given data.

Parameters

pBuffer	The buffer that holds the data to compress.
uSize	The size of pBuffer.

See Also: InitCompression; FinishCompression

Implemented in ZipArchiveLib::CDeflateCompressor, and ZipArchiveLib::CBzip2Compressor.

virtual int CZipCompressor::ConvertInternalError ( int iErr ) const

inlineprotectedvirtual

Converts an internal error code of the compressor to the ZipArchive Library error code.

Parameters

iErr	An internal error code.

Returns: A ZipArchive Library error code.

Reimplemented in ZipArchiveLib::CDeflateCompressor, and ZipArchiveLib::CBzip2Compressor.

static CZipCompressor* CZipCompressor::CreateCompressor	(	WORD	uMethod,
		CZipStorage *	pStorage
	)

static

A factory method that creates an appropriate compressor for the given compression method.

Parameters

uMethod	The compression method to create a compressor for. It can be one of the CompressionMethod values.
pStorage	The current storage object.

virtual DWORD CZipCompressor::Decompress	(	void *	pBuffer,
		DWORD	uSize
	)

pure virtual

Decompresses the given data.

Parameters

pBuffer	The buffer that receives the decompressed data.
uSize	The size of pBuffer.

Returns: The number of bytes decompressed and written to pBuffer.

Note: This method should be called repeatedly until it returns 0.

See Also: InitDecompression; FinishDecompression

Implemented in ZipArchiveLib::CDeflateCompressor, and ZipArchiveLib::CBzip2Compressor.

DWORD CZipCompressor::FillBuffer ( )

inlineprotected

Fills the read buffer.

Returns: The number of bytes read.

virtual void CZipCompressor::FinishCompression ( bool bAfterException )

inlinevirtual

The method called at the end of the compression process.

Parameters

bAfterException Set to true, if an exception occurred before or to false otherwise.

See Also: InitCompression; Compress

Reimplemented in ZipArchiveLib::CDeflateCompressor, and ZipArchiveLib::CBzip2Compressor.

virtual void CZipCompressor::FinishDecompression ( bool bAfterException )

inlinevirtual

The method called at the end of the decompression process.

Parameters

bAfterException Set to true, if an exception occurred before or to false otherwise.

See Also: InitDecompression; Decompress

Reimplemented in ZipArchiveLib::CDeflateCompressor, and ZipArchiveLib::CBzip2Compressor.

void CZipCompressor::FlushWriteBuffer ( )

inlineprotected

Flushes data in the buffer into the storage, encrypting the data if needed.

virtual const COptions* CZipCompressor::GetOptions ( ) const

inlinevirtual

Returns the current options of the compressor.

Returns: The current options for the compressor.

See Also: Compressing Data; CZipArchive::SetCompressionOptions; UpdateOptions

Reimplemented in ZipArchiveLib::CDeflateCompressor, and ZipArchiveLib::CBzip2Compressor.

void CZipCompressor::InitBuffer ( )

protected

Initializes the internal buffer.

See Also: ReleaseBuffer

virtual void CZipCompressor::InitCompression	(	int	iLevel,
		CZipFileHeader *	pFile,
		CZipCryptograph *	pCryptograph
	)

inlinevirtual

The method called when a new file is opened for compression.

Parameters

iLevel	The compression level.
pFile	The file being compressed.
pCryptograph	The current CZipCryptograph. It can be `NULL`, if no encryption is used.

See Also: Compress; FinishCompression

Reimplemented in ZipArchiveLib::CDeflateCompressor, and ZipArchiveLib::CBzip2Compressor.

virtual void CZipCompressor::InitDecompression	(	CZipFileHeader *	pFile,
		CZipCryptograph *	pCryptograph
	)

inlinevirtual

The method called when a new file is opened for extraction.

Parameters

pFile	The file being extracted.
pCryptograph	The current CZipCryptograph. It can be `NULL`, if no decryption is used.

See Also: Decompress; FinishDecompression

Reimplemented in ZipArchiveLib::CDeflateCompressor, ZipArchiveLib::CBzip2Compressor, and ZipArchiveLib::CBaseLibCompressor.

static bool CZipCompressor::IsCompressionSupported ( WORD uCompressionMethod )

inlinestatic

Returns the value indicating whether the given compression method is supported by the ZipArchive Library.

Parameters

uCompressionMethod The compression method. It can be one of the CompressionMethod values.

Returns: true, if the compression method is supported, false otherwise.

bool CZipCompressor::PrepareForSeek	(	CZipFileHeader *	pCurrentFile,
		COffsetsPair *	pPair
	)

Prepares the compressor for the seeking operation.

Parameters

pCurrentFile	The currently opened file.
pPair	The offsets pair describing the seek location.

See Also: Creating Seekable Compressed Data

void CZipCompressor::ReleaseBuffer ( )

inlineprotected

Releases the internal buffer.

See Also: InitBuffer

void CZipCompressor::ThrowError	(	int	iErr,
		bool	bInternal = `false`
	)

inlineprotected

Throws an exception with a given error code.

Parameters

iErr	An error code.
bInternal	`true`, if iErr is an internal error code and needs a conversion to the ZipArchive Library error code; `false` otherwise.

See Also: ConvertInternalError

void CZipCompressor::UpdateCrc	(	const void *	pBuffer,
		DWORD	uSize
	)

protected

Updates CRC value while decompression.

Parameters

pBuffer	A buffer with data for which the CRC value should be updated.
uSize	The size of the buffer.

void CZipCompressor::UpdateFileCrc	(	const void *	pBuffer,
		DWORD	uSize
	)

protected

Updates CRC value while compression.

Parameters

pBuffer	A buffer with data for which the CRC value should be updated.
uSize	The size of the buffer.

void CZipCompressor::UpdateOptions ( const COptionsMap & optionsMap )

Updates the current options with the options stored in optionsMap, if the appropriate options are present in the map.

Parameters

optionsMap The map to get the new options from.

See Also: Compressing Data; GetOptions

virtual void CZipCompressor::UpdateOptions ( const COptions * pOptions )

inlineprotectedvirtual

Updates the current options with the new options.

Parameters

pOptions The new options to apply.

Reimplemented in ZipArchiveLib::CDeflateCompressor, and ZipArchiveLib::CBzip2Compressor.

void CZipCompressor::WriteBuffer	(	char *	pBuffer,
		DWORD	uSize
	)

inlineprotected

Writes the buffer into the storage, encrypting the data if needed.

Parameters

pBuffer	The buffer with data to write.
uSize	The size of the buffer.

Member Data Documentation

CZipAutoBuffer CZipCompressor::m_pBuffer

protected

A buffer that receives compressed data or provides data for decompression.

CZipCryptograph* CZipCompressor::m_pCryptograph

protected

The current cryptograph.

CZipFileHeader* CZipCompressor::m_pFile

protected

The file header being compressed or decompressed.

CZipStorage* CZipCompressor::m_pStorage

protected

The current storage object.

ZIP_SIZE_TYPE CZipCompressor::m_uComprLeft

The number of bytes left to compress.

DWORD CZipCompressor::m_uCrc32

The CRC32 file checksum.

ZIP_SIZE_TYPE CZipCompressor::m_uUncomprLeft

The number of bytes left to decompress.

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

ZipCompressor.h

Classes

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation