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CZipFileHeader Class Reference

#include <ZipFileHeader.h>

List of all members.

Public Member Functions
bool	CompressionEfficient ()
	CZipFileHeader (const CZipFileHeader &header)
CZipString	GetComment () const
WORD	GetCommentSize () const
int	GetCompressionLevel () const
float	GetCompressionRatio ()
WORD	GetDataDescriptorSize (bool bConsiderSignature=false) const
WORD	GetDataDescriptorSize (const CZipStorage *pStorage) const
ZIP_SIZE_TYPE	GetDataSize (bool bUseLocal=false, bool bReal=true) const
DWORD	GetEncryptedInfoSize () const
int	GetEncryptionMethod () const
CZipString &	GetFileName (bool bClearBuffer=true)
DWORD	GetLocalSize (bool bReal) const
DWORD	GetOriginalAttributes () const
DWORD	GetSize () const
CZipStringStoreSettings	GetStringStoreSettings ()
DWORD	GetSystemAttr ()
int	GetSystemCompatibility () const
time_t	GetTime () const
bool	HasTime ()
bool	IsDataDescriptor () const
bool	IsDirectory ()
bool	IsEncrypted () const
bool	IsWinZipAesEncryption () const
CZipFileHeader &	operator= (const CZipFileHeader &header)
int	PredictFileNameSize () const
void	SetComment (LPCTSTR lpszComment)
void	SetFileName (LPCTSTR lpszFileName)
void	SetTime (const time_t &ttime)
Public Attributes
CZipExtraField	m_aCentralExtraData
	The central extra field.
CZipExtraField	m_aLocalExtraData
	The local extra field. Do not modify after you have started compressing the file.
ZIP_SIZE_TYPE	m_uComprSize
	The compressed size.
DWORD	m_uCrc32
	The crc-32 value.
WORD	m_uFlag
	A general purpose bit flag.
WORD	m_uInternalAttr
	Internal file attributes.
ZIP_SIZE_TYPE	m_uLocalComprSize
	The compressed size written in the local header.
ZIP_SIZE_TYPE	m_uLocalUncomprSize
	The uncompressed size written in the local header.
WORD	m_uMethod
	The compression method. Can be one of the CZipCompressor::CompressionMethod values.
WORD	m_uModDate
	The file last modification date.
WORD	m_uModTime
	The file last modification time.
ZIP_SIZE_TYPE	m_uOffset
	Relative offset of the local header with respect to CZipFileHeader::m_uVolumeStart.
ZIP_SIZE_TYPE	m_uUncomprSize
	The uncompressed size.
WORD	m_uVersionMadeBy
	The "made by" version and the system compatibility.
WORD	m_uVersionNeeded
	The version needed to extract the file.
ZIP_VOLUME_TYPE	m_uVolumeStart
	The volume number at which the compressed file starts.
Static Public Attributes
static char	m_gszLocalSignature []
	The local file header signature.
static char	m_gszSignature []
	The central file header signature.
Protected Member Functions
bool	CheckDataDescriptor (CZipStorage *pStorage) const
bool	CheckLengths (bool local) const
bool	NeedsDataDescriptor () const
bool	NeedsSignatureInDataDescriptor (const CZipStorage *pStorage) const
void	PrepareData (int iLevel, bool bSegm)
void	PrepareFileName ()
bool	Read (CZipCentralDir &centralDir, bool bReadSignature)
bool	ReadLocal (CZipCentralDir &centralDir)
void	SetSystemAttr (DWORD uAttr)
void	SetSystemCompatibility (int iSystemID)
void	UpdateFlag (bool bSegm)
void	UpdateLocalHeader (CZipStorage *pStorage)
void	UpdateLocalZip64 ()
DWORD	Write (CZipStorage *pStorage)
void	WriteCrc32 (char *pBuf) const
void	WriteDataDescriptor (CZipStorage *pStorage)
void	WriteLocal (CZipStorage *pStorage)
void	WriteSmallDataDescriptor (char *pDest, bool bLocal=true)
Static Protected Member Functions
static bool	VerifySignature (CZipAutoBuffer &buf)
Protected Attributes
bool	m_bIgnoreCrc32
	A value indicating whether to ignore Crc32 checking or not.
BYTE	m_uEncryptionMethod
	The file encryption method. Can be one of the CZipCryptograph::EncryptionMethod values.
DWORD	m_uExternalAttr
	External file attributes.
WORD	m_uLocalFileNameSize
	The local filename length.
Friends
class	CZipArchive
class	CZipCentralDir

---

Detailed Description

Represents a single file stored in a zip archive.

---

Member Function Documentation

bool CZipFileHeader::CheckDataDescriptor

(

CZipStorage *

pStorage

)

const [protected]

Validates an existing data descriptor after file decompression.

Parameters:

pStorage

The storage to read the data descriptor from.

Returns:

true, if the data descriptor is valid; false otherwise.

bool CZipFileHeader::CheckLengths

(

bool

local

)

const [inline, protected]

Validates the member fields lengths. The tested fields are: filename, extra fields and comment.

Returns:

false, if any of the lengths exceeds the allowed value.

bool CZipFileHeader::CompressionEfficient

(

)

[inline]

Gets a value indicating if the compression is efficient.

Returns:

true if the compression is efficient; false if the file should be stored without the compression instead.

CZipString CZipFileHeader::GetComment

(

)

const

Gets the file comment.

Returns:

The file comment.

WORD CZipFileHeader::GetCommentSize

(

)

const [inline]

Gets the comment size.

Returns:

The number of characters in the comment not including a terminating NULL character.

int CZipFileHeader::GetCompressionLevel

(

)

const

Gets an approximate file compression level.

Returns:

The compression level. May not be the real value used when compressing the file.

float CZipFileHeader::GetCompressionRatio

(

)

[inline]

Gets the compression ratio.

Returns:

The compression ratio of the file.

WORD CZipFileHeader::GetDataDescriptorSize

(

bool

bConsiderSignature = false

)

const

Gets the data descriptor size as it is required for the current file. Takes into account various factors, such as the need for the data descriptor signature or for the Zip64 format.

Parameters:

bConsiderSignature

true, if the data descriptor signature is needed; false otherwise.

Returns:

The required data descriptor size in bytes.

WORD CZipFileHeader::GetDataDescriptorSize

(

const CZipStorage *

pStorage

)

const [inline]

Gets the data descriptor size as it is required for the current file. Takes into account various factors, such as the archive segmentation type, encryption and the need for the Zip64 format.

Parameters:

pStorage

The storage to test for segmentation type.

Returns:

The required data descriptor size in bytes.

ZIP_SIZE_TYPE CZipFileHeader::GetDataSize	(	bool	bUseLocal = false,
		bool	bReal = true
	)			const [inline]

Gets the size of the compressed data.

Parameters:

	bUseLocal	If true, uses m_uLocalComprSize; otherwise uses m_uComprSize;
	bReal	If true, the returned value does not include the encrypted information size, only the data size. If false, the encrypted information size is added (you should not use this value when the file exists in the archive).

Returns:

The compressed data size in bytes.

See also:

GetEncryptedInfoSize

DWORD CZipFileHeader::GetEncryptedInfoSize

(

)

const [inline]

Gets the encrypted information size. The returned value depends on the used encryption method.

Returns:

The encrypted information size in bytes.

int CZipFileHeader::GetEncryptionMethod

(

)

const [inline]

Gets the encryption method of the file.

Returns:

The file encryption method. Can be one of the CZipCryptograph::EncryptionMethod values.

CZipString& CZipFileHeader::GetFileName

(

bool

bClearBuffer = true

)

Gets the filename. If necessary, performs the conversion using the current filename code page. Caches the result of conversion for faster access the next time.

Parameters:

bClearBuffer

If true, releases the internal buffer after performing the filename conversion. If false, the internal buffer is not released and both representations of the filename are kept in memory (converted and not converted). This takes more memory, but the conversion does not take place again when the central directory is written back to the archive.

Returns:

The converted filename.

See also:

Unicode Support: Using Non-English Characters in Filenames and Comments

GetStringStoreSettings

CZipStringStoreSettings::m_uNameCodePage

DWORD CZipFileHeader::GetLocalSize

(

bool

bReal

)

const

Gets the local header size. Before calling this method, the local information must be up-to-date (see Requesting Information, Predicting Names and Sizes for more information).

Parameters:

bReal

If true, uses the real local filename size. If false, predicts the filename size.

Returns:

The local header size in bytes.

DWORD CZipFileHeader::GetOriginalAttributes

(

)

const [inline]

Gets the file attributes exactly as they are stored in the archive.

Returns:

The file attributes as they are stored in the archive. No conversion is performed.

Note:

The attributes for Linux are stored shifted left by 16 bits in this field.

See also:

GetSystemAttr

DWORD CZipFileHeader::GetSize

(

)

const

Gets the total size of the structure in the central directory.

Returns:

The total size in bytes.

CZipStringStoreSettings CZipFileHeader::GetStringStoreSettings

(

)

[inline]

Gets the string store settings for the file.

Returns:

The string store settings.

See also:

Unicode Support: Using Non-English Characters in Filenames and Comments

CZipArchive::GetStringStoreSettings

DWORD CZipFileHeader::GetSystemAttr

(

)

Gets the file attributes.

Returns:

The file attributes, converted if necessary to be compatible with the current system.

Note:

Throws an exception, if the archive system or the current system is not supported by the ZipArchive Library.

See also:

GetOriginalAttributes

int CZipFileHeader::GetSystemCompatibility

(

)

const [inline]

Gets the file system compatibility. External software can use this information e.g. to determine end-of-line format for text files etc. The ZipArchive Library uses it to perform a proper file attributes conversion.

Returns:

The file system compatibility. Can be one of the ZipCompatibility::ZipPlatforms values.

See also:

CZipArchive::GetSystemComatibility

ZipPlatform::GetSystemID

time_t CZipFileHeader::GetTime

(

)

const

Gets the file modification time.

Returns:

The modification time.

See also:

SetTime

bool CZipFileHeader::HasTime

(

)

[inline]

Returns the value indicating whether the current CZipFileHeader object has the time set or not.

Returns:

true, if the time is set; false otherwise.

bool CZipFileHeader::IsDataDescriptor

(

)

const [inline]

Gets a value indicating whether the data descriptor is present or not.

Returns:

true, if the data descriptor is present; false otherwise.

bool CZipFileHeader::IsDirectory

(

)

Gets a value indicating whether the file represents a directory or not. This method checks the file attributes. If the attributes value is zero, the method checks for the presence of a path separator at the end of the filename. If the path separator is present, the file is assumed to be a directory.

Returns:

true, if the file represents a directory; false otherwise.

bool CZipFileHeader::IsEncrypted

(

)

const [inline]

Gets a value indicating if the file is encrypted or not. If the file is encrypted, you need to set the password with the CZipArchive::SetPassword method before decompressing the file.

Returns:

true if the file is encrypted; false otherwise.

See also:

CZipArchive::SetPassword

bool CZipFileHeader::IsWinZipAesEncryption

(

)

const [inline]

Gets a value indicating if the file is encrypted using WinZip AES encryption method or not.

Returns:

true, if the file is encrypted using WinZip AES encryption method; false otherwise.

bool CZipFileHeader::NeedsDataDescriptor

(

)

const [protected]

Gets a value indicating whether the file needs the data descriptor. The data descriptor is needed when a file is encrypted or the Zip64 format needs to be used.

Returns:

true, if the data descriptor is needed; false otherwise.

int CZipFileHeader::PredictFileNameSize

(

)

const [inline]

Predicts the filename size after conversion using the current filename code page.

Returns:

The number of characters not including a terminating NULL character.

void CZipFileHeader::PrepareData	(	int	iLevel,
		bool	bSegm
	)			[protected]

Prepares the data for writing when adding a new file. When Zip64 extensions are required for this file, this method adds Zip64 extra data to m_aLocalExtraData.

Parameters:

	iLevel	The compression level.
	bSegm	Set to true, if the archive is segmented; false otherwise.

void CZipFileHeader::PrepareFileName

(

)

[inline, protected]

Prepares the filename for writing to the archive.

bool CZipFileHeader::Read	(	CZipCentralDir &	centralDir,
		bool	bReadSignature
	)			[protected]

Reads the central file header from pStorage and validates the read data.

Parameters:

	centralDir	The current central directory.
	bReadSignature	true, if the the central header signature should be read; false otherwise.

Returns:

true, if the read data is consistent; false otherwise.

Note:

Throws exceptions.

bool CZipFileHeader::ReadLocal

(

CZipCentralDir &

centralDir

)

[protected]

Reads the local file header from an archive and validates the read data.

Parameters:

centralDir

The current central directory.

Returns:

true, if read data is consistent; false otherwise.

Note:

Throws exceptions.

See also:

CZipArchive::SetIgnoredConsistencyChecks

void CZipFileHeader::SetComment

(

LPCTSTR

lpszComment

)

Sets the file comment.

Parameters:

lpszComment

The file comment.

void CZipFileHeader::SetFileName

(

LPCTSTR

lpszFileName

)

Sets the filename.

Parameters:

lpszFileName

The filename to set.

void CZipFileHeader::SetSystemAttr

(

DWORD

uAttr

)

[protected]

Sets the file attributes. To set the attributes of this structure use the CZipArchive::SetFileHeaderAttr method.

Parameters:

uAttr

The attributes to set.

Note:

Throws exceptions, if the archive system or the current system is not supported by the ZipArchive Library.

See also:

CZipArchive::SetFileHeaderAttr

GetSystemAttr

void CZipFileHeader::SetSystemCompatibility

(

int

iSystemID

)

[inline, protected]

Sets the file system compatibility.

Parameters:

iSystemID

The file system compatibility. Can be one of the ZipCompatibility::ZipPlatforms values.

See also:

GetSystemCompatibility

void CZipFileHeader::SetTime

(

const time_t &

ttime

)

Sets the file modification date.

Parameters:

ttime

The date to set. If this value is incorrect, the date defaults to January 1, 1980.

See also:

GetTime

void CZipFileHeader::UpdateFlag

(

bool

bSegm

)

[inline, protected]

Updates the general purpose bit flag.

Parameters:

bSegm

true, if the current archive is a segmented archive; false otherwise.

void CZipFileHeader::UpdateLocalHeader

(

CZipStorage *

pStorage

)

[protected]

Updates the local header in the archive after is has already been written.

Parameters:

pStorage

The storage to update the data descriptor in.

void CZipFileHeader::UpdateLocalZip64

(

)

[protected]

Creates Zip64 extra data in the local extra field, if needed.

Note:

Throws exceptions.

static bool CZipFileHeader::VerifySignature

(

CZipAutoBuffer &

buf

)

[inline, static, protected]

Verifies the central header signature.

Parameters:

buf

The buffer that contains the signature to verify.

Returns:

true, if the signature is valid; false otherwise.

DWORD CZipFileHeader::Write

(

CZipStorage *

pStorage

)

[protected]

Writes the central file header to pStorage.

Parameters:

pStorage

The storage to write the central file header to.

Returns:

The size of the file header.

Note:

Throws exceptions.

void CZipFileHeader::WriteCrc32

(

char *

pBuf

)

const [protected]

Writes the Crc32 to pBuf.

Parameters:

pBuf

The buffer to write the Crc32 to. Must have be of at least 4 bytes size.

void CZipFileHeader::WriteDataDescriptor

(

CZipStorage *

pStorage

)

[protected]

Writes the data descriptor taking into account the Zip64 format.

Parameters:

pStorage

The storage to write the data descriptor to.

void CZipFileHeader::WriteLocal

(

CZipStorage *

pStorage

)

[protected]

Writes the local file header to the pStorage. The filename and extra field are the same as those that will be stored in the central directory.

Parameters:

pStorage

The storage to write the local file header to.

Note:

Throws exceptions.

void CZipFileHeader::WriteSmallDataDescriptor	(	char *	pDest,
		bool	bLocal = true
	)			[protected]

Writes the data descriptor.

Parameters:

	pDest	The buffer to receive the data.
	bLocal	Set to true, if the local sizes are used; false otherwise.

---

Member Data Documentation

CZipExtraField CZipFileHeader::m_aCentralExtraData

The central extra field.

CZipExtraField CZipFileHeader::m_aLocalExtraData

The local extra field. Do not modify after you have started compressing the file.

bool CZipFileHeader::m_bIgnoreCrc32 [protected]

A value indicating whether to ignore Crc32 checking or not.

char CZipFileHeader::m_gszLocalSignature[] [static]

The local file header signature.

char CZipFileHeader::m_gszSignature[] [static]

The central file header signature.

ZIP_SIZE_TYPE CZipFileHeader::m_uComprSize

The compressed size.

DWORD CZipFileHeader::m_uCrc32

The crc-32 value.

BYTE CZipFileHeader::m_uEncryptionMethod [protected]

The file encryption method. Can be one of the CZipCryptograph::EncryptionMethod values.

DWORD CZipFileHeader::m_uExternalAttr [protected]

External file attributes.

WORD CZipFileHeader::m_uFlag

A general purpose bit flag.

WORD CZipFileHeader::m_uInternalAttr

Internal file attributes.

ZIP_SIZE_TYPE CZipFileHeader::m_uLocalComprSize

The compressed size written in the local header.

WORD CZipFileHeader::m_uLocalFileNameSize [protected]

The local filename length.

ZIP_SIZE_TYPE CZipFileHeader::m_uLocalUncomprSize

The uncompressed size written in the local header.

WORD CZipFileHeader::m_uMethod

The compression method. Can be one of the CZipCompressor::CompressionMethod values.

WORD CZipFileHeader::m_uModDate

The file last modification date.

WORD CZipFileHeader::m_uModTime

The file last modification time.

ZIP_SIZE_TYPE CZipFileHeader::m_uOffset

Relative offset of the local header with respect to CZipFileHeader::m_uVolumeStart.

ZIP_SIZE_TYPE CZipFileHeader::m_uUncomprSize

The uncompressed size.

WORD CZipFileHeader::m_uVersionMadeBy

The "made by" version and the system compatibility.

WORD CZipFileHeader::m_uVersionNeeded

The version needed to extract the file.

ZIP_VOLUME_TYPE CZipFileHeader::m_uVolumeStart

The volume number at which the compressed file starts.

---

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

• ZipFileHeader.h

Copyright © 2000 - 2007 Artpol Software - Tadeusz Dracz

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