zipfileheader.cpp

ZIP压缩代码：基于开源ZipArchive和zlib

////////////////////////////////////////////////////////////////////////////////
// $Workfile: ZipFileHeader.cpp $
// $Archive: /ZipArchive_STL/ZipFileHeader.cpp $
// $Date: 02-04-01 2:15 $ $Author: Tadeusz Dracz $
////////////////////////////////////////////////////////////////////////////////
// This source file is part of the ZipArchive library source distribution and
// is Copyright 2000-2003 by Tadeusz Dracz (http://www.artpol-software.com/)
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
// 
// For the licensing details see the file License.txt
////////////////////////////////////////////////////////////////////////////////


#include "stdafx.h"
#include "ZipFileHeader.h"
#include "ZipAutoBuffer.h"
#include "ZipArchive.h"
#include "ZipPlatform.h"
#include "ZipCompatibility.h"
#include <time.h>

#define FILEHEADERSIZE	46
#define LOCALFILEHEADERSIZE	30

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////
char CZipFileHeader::m_gszSignature[] = {0x50, 0x4b, 0x01, 0x02};
char CZipFileHeader::m_gszLocalSignature[] = {0x50, 0x4b, 0x03, 0x04};
CZipFileHeader::CZipFileHeader()
{
	m_uExternalAttr = 0;//ZipPlatform::GetDefaultAttributes();
	m_uModDate = m_uModTime = 0;
	m_uMethod = Z_DEFLATED;
// 	SetSystemCompatibility(ZipPlatform::m_sSystemID);
}

CZipFileHeader::~CZipFileHeader()
{

}

// read the header from the central dir
bool CZipFileHeader::Read(CZipStorage *pStorage)
{
// 	// just in case
// 	m_pszComment.Release();
// 	m_pszFileName.Release();
	WORD uFileNameSize, uCommentSize, uExtraFieldSize;
	CZipAutoBuffer buf(FILEHEADERSIZE);
	pStorage->Read(buf, FILEHEADERSIZE, true);		
	memcpy(&m_szSignature,		buf, 4);
	memcpy(&m_uVersionMadeBy,	buf + 4, 2);
	memcpy(&m_uVersionNeeded,	buf + 6, 2);
	memcpy(&m_uFlag,			buf + 8, 2);
	memcpy(&m_uMethod,			buf + 10, 2);
	memcpy(&m_uModTime,			buf + 12, 2);
	memcpy(&m_uModDate,			buf + 14, 2);
	memcpy(&m_uCrc32,			buf + 16, 4);
	memcpy(&m_uComprSize,		buf + 20, 4);
	memcpy(&m_uUncomprSize,		buf + 24, 4);
	memcpy(&uFileNameSize,		buf + 28, 2);
	memcpy(&uExtraFieldSize,	buf + 30, 2);
	memcpy(&uCommentSize,		buf + 32, 2);
	memcpy(&m_uDiskStart,		buf + 34, 2);
	memcpy(&m_uInternalAttr,	buf + 36, 2);
	memcpy(&m_uExternalAttr,	buf + 38, 4);
	memcpy(&m_uOffset,			buf + 42, 4);
	buf.Release();

	if (memcmp(m_szSignature, m_gszSignature, 4) != 0)
		return false;

	int iCurDsk = pStorage->GetCurrentDisk();
	m_pszFileName.Allocate(uFileNameSize); // don't add NULL at the end
	pStorage->Read(m_pszFileName, uFileNameSize, true);
	if (uExtraFieldSize)
	{
		ASSERT(!m_pExtraField.IsAllocated());
		m_pExtraField.Allocate(uExtraFieldSize);
		pStorage->Read(m_pExtraField, uExtraFieldSize, true);
	}
	if (uCommentSize)
	{
		m_pszComment.Allocate(uCommentSize);
		pStorage->Read(m_pszComment, uCommentSize, true);
	}
	
	return pStorage->GetCurrentDisk() == iCurDsk; // check that the whole header is on the one disk
}

time_t CZipFileHeader::GetTime()const
{
	struct tm atm;
	atm.tm_sec = (m_uModTime & ~0xFFE0) << 1;
	atm.tm_min = (m_uModTime & ~0xF800) >> 5;
	atm.tm_hour = m_uModTime >> 11;

	atm.tm_mday = m_uModDate & ~0xFFE0;
	atm.tm_mon = ((m_uModDate & ~0xFE00) >> 5) - 1;
	atm.tm_year = (m_uModDate >> 9) + 80;
	atm.tm_isdst = -1;
	return mktime(&atm);
}

// write the header to the central dir
DWORD CZipFileHeader::Write(CZipStorage *pStorage)
{
	WORD uFileNameSize = GetFileNameSize(), uCommentSize = GetCommentSize(),
		uExtraFieldSize = GetExtraFieldSize();
	DWORD iSize = FILEHEADERSIZE + uFileNameSize + uCommentSize + uExtraFieldSize;
	CZipAutoBuffer buf(iSize);
	memcpy(buf, &m_szSignature, 4);
	memcpy(buf + 4, &m_uVersionMadeBy, 2);
	memcpy(buf + 6, &m_uVersionNeeded, 2);
	memcpy(buf + 8, &m_uFlag, 2);
	memcpy(buf + 10, &m_uMethod, 2);
	memcpy(buf + 12, &m_uModTime, 2);
	memcpy(buf + 14, &m_uModDate, 2);
	memcpy(buf + 16, &m_uCrc32, 4);
	memcpy(buf + 20, &m_uComprSize, 4);
	memcpy(buf + 24, &m_uUncomprSize, 4);
	memcpy(buf + 28, &uFileNameSize, 2);
	memcpy(buf + 30, &uExtraFieldSize, 2);
	memcpy(buf + 32, &uCommentSize, 2);
	memcpy(buf + 34, &m_uDiskStart, 2);
	memcpy(buf + 36, &m_uInternalAttr, 2);
	memcpy(buf + 38, &m_uExternalAttr, 4);
	memcpy(buf + 42, &m_uOffset, 4);

	memcpy(buf + 46, m_pszFileName, uFileNameSize);

	if (uExtraFieldSize)
		memcpy(buf + 46 + uFileNameSize, m_pExtraField, uExtraFieldSize);
	
	if (uCommentSize)
		memcpy(buf + 46 + uFileNameSize + uExtraFieldSize, m_pszComment, uCommentSize);
	
	pStorage->Write(buf, iSize, true);
	return iSize;
}

bool CZipFileHeader::ReadLocal(CZipStorage *pStorage, WORD& iLocExtrFieldSize)
{
	char buf[LOCALFILEHEADERSIZE];
	pStorage->Read(buf, LOCALFILEHEADERSIZE, true);
	if (memcmp(buf, m_gszLocalSignature, 4) != 0)
		return false;
	
	bool bIsDataDescr = (((WORD)*(buf + 6)) & 8) != 0;
	
	WORD uFileNameSize = GetFileNameSize();
	WORD uTemp; 
	memcpy(&uTemp, buf+6, 2); 
	if (( (uTemp & 0xf) != (m_uFlag & 0xf))	
		||(memcmp(buf + 8, &m_uMethod, 2) != 0)
		|| (m_uMethod && (m_uMethod != Z_DEFLATED))
		|| (memcmp(buf + 26, &uFileNameSize, 2) != 0))
		return false;

// jeszcze mo縩aby por體na