archiverecovery.cpp

eMule0.44b的原代码

	bool retVal = false;
	try
	{
		// Ideally this zip file will not have a comment and the End-CD will be easy to find
		zipInput->Seek(-22, CFile::end);
		if (!(readUInt32(zipInput) == ZIP_END_CD_MAGIC))
		{
			// Have to look for it, comment could be up to 65535 chars but only try with less than 1k
			zipInput->Seek(-1046, CFile::end);
			if (!scanForZipMarker(zipInput, (uint32)ZIP_END_CD_MAGIC, 1046))
				return false;
			// Skip it again
			readUInt32(zipInput);
		}

		// Found End-CD
		// Only interested in offset of first CD
		zipInput->Seek(12, CFile::current);
		uint32 startOffset = readUInt32(zipInput);
		if (!IsFilled(startOffset, zipInput->GetLength(), filled))
			return false;

		// Goto first CD and start reading
		zipInput->Seek(startOffset, CFile::begin);
		ZIP_CentralDirectory *cdEntry;
		while (readUInt32(zipInput) == ZIP_CD_MAGIC)
		{
			cdEntry = new ZIP_CentralDirectory;
			cdEntry->versionMadeBy				= readUInt16(zipInput);
			cdEntry->versionToExtract			= readUInt16(zipInput);
			cdEntry->generalPurposeFlag			= readUInt16(zipInput);
			cdEntry->compressionMethod			= readUInt16(zipInput);
			cdEntry->lastModFileTime			= readUInt16(zipInput);
			cdEntry->lastModFileDate			= readUInt16(zipInput);
			cdEntry->crc32						= readUInt32(zipInput);
			cdEntry->lenCompressed				= readUInt32(zipInput);
			cdEntry->lenUnompressed				= readUInt32(zipInput);
			cdEntry->lenFilename				= readUInt16(zipInput);
			cdEntry->lenExtraField				= readUInt16(zipInput);
			cdEntry->lenComment					= readUInt16(zipInput);
			cdEntry->diskNumberStart			= readUInt16(zipInput);
			cdEntry->internalFileAttributes		= readUInt16(zipInput);
			cdEntry->externalFileAttributes		= readUInt32(zipInput);
			cdEntry->relativeOffsetOfLocalHeader= readUInt32(zipInput);

			if (cdEntry->lenFilename > 0)
			{
				cdEntry->filename					= new BYTE[cdEntry->lenFilename];
				zipInput->Read(cdEntry->filename, cdEntry->lenFilename);
			}
			if (cdEntry->lenExtraField > 0)
			{
				cdEntry->extraField					= new BYTE[cdEntry->lenExtraField];
				zipInput->Read(cdEntry->extraField, cdEntry->lenExtraField);
			}
			if (cdEntry->lenComment > 0)
			{
				cdEntry->comment					= new BYTE[cdEntry->lenComment];
				zipInput->Read(cdEntry->comment, cdEntry->lenComment);
			}

			centralDirectoryEntries->AddTail(cdEntry);
		}

		retVal = true;
	}
	catch (CFileException* error){
		error->Delete();
	}
	catch (...){
		ASSERT(0);
	}
	return retVal;
}

bool CArchiveRecovery::processZipEntry(CFile *zipInput, CFile *zipOutput, uint32 available, CTypedPtrList<CPtrList, ZIP_CentralDirectory*> *centralDirectoryEntries)
{
	if (available < 26)
		return false;

	bool retVal = false;
	try
	{
		// Need to know where it started
		long startOffset = zipOutput->GetPosition();

		// Entry format :
		//  4      2 bytes  Version needed to extract
		//  6      2 bytes  General purpose bit flag
		//  8      2 bytes  Compression method
		// 10      2 bytes  Last mod file time
		// 12      2 bytes  Last mod file date
		// 14      4 bytes  CRC-32
		// 18      4 bytes  Compressed size (n)
		// 22      4 bytes  Uncompressed size
		// 26      2 bytes  Filename length (f)
		// 28      2 bytes  Extra field length (e)
		//        (f)bytes  Filename
		//        (e)bytes  Extra field
		//        (n)bytes  Compressed data

		// Read header
		if (readUInt32(zipInput) != ZIP_LOCAL_HEADER_MAGIC)
			return false;

		ZIP_Entry entry={0};
		entry.versionToExtract		= readUInt16(zipInput);
		entry.generalPurposeFlag	= readUInt16(zipInput);
		entry.compressionMethod		= readUInt16(zipInput);
		entry.lastModFileTime		= readUInt16(zipInput);
		entry.lastModFileDate		= readUInt16(zipInput);
		entry.crc32					= readUInt32(zipInput);
		entry.lenCompressed			= readUInt32(zipInput);
		entry.lenUncompressed		= readUInt32(zipInput);
		entry.lenFilename			= readUInt16(zipInput);
		entry.lenExtraField			= readUInt16(zipInput);
		
		// Do some quick checks at this stage that data is looking ok
		if ((entry.crc32 == 0) || (entry.lenCompressed == 0) || (entry.lenUncompressed == 0) || (entry.lenFilename == 0))
			return false;

		// Is this entry complete
		if ((entry.lenFilename + entry.lenExtraField + entry.lenCompressed) > (available - 26))
		{
			// Move the file pointer to the start of the next entry
			zipInput->Seek((entry.lenFilename + entry.lenExtraField + entry.lenCompressed), CFile::current);
			return false;
		}

		// Filename
		if (entry.lenFilename > MAX_PATH)
			return false; // Possibly corrupt, don't allocate lots of memory
		entry.filename = new BYTE[entry.lenFilename];
		if (zipInput->Read(entry.filename, entry.lenFilename) != entry.lenFilename)
		{
			delete [] entry.filename;
			return false;
		}

		// Extra data
		if (entry.lenExtraField > 0)
		{
			entry.extraField = new BYTE[entry.lenExtraField];
			zipInput->Read(entry.extraField, entry.lenExtraField);
		}

		// Output
		writeUInt32(zipOutput, ZIP_LOCAL_HEADER_MAGIC);
		writeUInt16(zipOutput, entry.versionToExtract);
		writeUInt16(zipOutput, entry.generalPurposeFlag);
		writeUInt16(zipOutput, entry.compressionMethod);
		writeUInt16(zipOutput, entry.lastModFileTime);
		writeUInt16(zipOutput, entry.lastModFileDate);
		writeUInt32(zipOutput, entry.crc32);
		writeUInt32(zipOutput, entry.lenCompressed);
		writeUInt32(zipOutput, entry.lenUncompressed);
		writeUInt16(zipOutput, entry.lenFilename);
		writeUInt16(zipOutput, entry.lenExtraField);
		if (entry.lenFilename > 0)
			zipOutput->Write(entry.filename, entry.lenFilename);
		if (entry.lenExtraField > 0)
			zipOutput->Write(entry.extraField, entry.lenExtraField);

		// Read and write compressed data to avoid reading all into memory
		uint32 written = 0;
		BYTE buf[4096];
		uint32 lenChunk = 4096;
		while (written < entry.lenCompressed)
		{
			lenChunk  = (entry.lenCompressed - written);
			if (lenChunk > 4096)
				lenChunk = 4096;
			lenChunk = zipInput->Read(buf, lenChunk);
			if (lenChunk == 0)
				break;
			written += lenChunk;
			zipOutput->Write(buf, lenChunk);
		}
		zipOutput->Flush();

		//Central directory:
		if (centralDirectoryEntries != NULL)
		{
			ZIP_CentralDirectory *cdEntry = new ZIP_CentralDirectory;
			cdEntry->header = ZIP_CD_MAGIC;
			cdEntry->versionMadeBy = entry.versionToExtract;
			cdEntry->versionToExtract = entry.versionToExtract;
			cdEntry->generalPurposeFlag = entry.generalPurposeFlag;
			cdEntry->compressionMethod = entry.compressionMethod;
			cdEntry->lastModFileTime = entry.lastModFileTime;
			cdEntry->lastModFileDate = entry.lastModFileDate;
			cdEntry->crc32 = entry.crc32;
			cdEntry->lenCompressed = entry.lenCompressed;
			cdEntry->lenUnompressed = entry.lenUncompressed;
			cdEntry->lenFilename = entry.lenFilename;
			cdEntry->lenExtraField = entry.lenExtraField;
			cdEntry->lenComment = strlen(ZIP_COMMENT);
			cdEntry->diskNumberStart = 0;
			cdEntry->internalFileAttributes = 1;
			cdEntry->externalFileAttributes = 0x81B60020;
			cdEntry->relativeOffsetOfLocalHeader = startOffset;
			cdEntry->filename = entry.filename;
			if (entry.lenExtraField > 0)
				cdEntry->extraField = entry.extraField;
			cdEntry->comment = new BYTE[cdEntry->lenComment];
			memcpy(cdEntry->comment, ZIP_COMMENT, cdEntry->lenComment);

			centralDirectoryEntries->AddTail(cdEntry);
		}
		else
		{
			delete [] entry.filename;
			if (entry.lenExtraField > 0)
				delete [] entry.extraField;
		}
		retVal = true;
	}
	catch (CFileException* error){
		error->Delete();
	}
	catch (...){
		ASSERT(0);
	}
	return retVal;
}

void CArchiveRecovery::DeleteMemory(ThreadParam *tp)
{
	POSITION pos = tp->filled->GetHeadPosition();
	while (pos != NULL)
		delete tp->filled->GetNext(pos);
	tp->filled->RemoveAll();
	delete tp->filled;
	delete tp;
}

bool CArchiveRecovery::CopyFile(CPartFile *partFile, CTypedPtrList<CPtrList, Gap_Struct*> *filled, CString tempFileName)
{
	bool retVal = false;
	try
	{
		CFile srcFile;
		if (!srcFile.Open(partFile->GetFilePath(), CFile::modeRead | CFile::shareDenyNone))
			return false;

		// Open destination file and set length to last filled end position
		CFile destFile;
		destFile.Open(tempFileName, CFile::modeWrite | CFile::shareDenyWrite | CFile::modeCreate);
		Gap_Struct *fill = filled->GetTail();
		destFile.SetLength(fill->end);

		BYTE buffer[4096];
		uint32 read;
		uint32 copied;

		// Loop through filled areas and copy data
		partFile->m_bPreviewing = true;
		POSITION pos = filled->GetHeadPosition();
		while (pos != NULL)
		{
			fill = filled->GetNext(pos);
			copied = 0;
			srcFile.Seek(fill->start, CFile::begin);
			destFile.Seek(fill->start, CFile::begin);
			while ((read = srcFile.Read(buffer, 4096)) > 0)
			{
				destFile.Write(buffer, read);
				copied += read;
				// Stop when finished fill (don't worry about extra)
				if (fill->start + copied >= fill->end)
					break;
			}
		}
		destFile.Close();
		srcFile.Close();
		partFile->m_bPreviewing = false;

		retVal = true;
	}
	catch (CFileException* error){
		error->Delete();
	}
	catch (...){
		ASSERT(0);
	}

	return retVal;
}

bool CArchiveRecovery::recoverRar(CFile *rarInput, CFile *rarOutput, CTypedPtrList<CPtrList, Gap_Struct*> *filled)
{
	bool retVal = false;
	long fileCount = 0;
	try
	{
		BYTE start[] = RAR_START_OF_FILE;
		rarOutput->Write(start, sizeof(start));

		RAR_BlockFile *block;
		while ((block = scanForRarFileHeader(rarInput, (uint32)rarInput->GetLength())) != NULL)
		{
			if (IsFilled(block->offsetData, block->offsetData + block->dataLength, filled))
			{
				// Don't include directories in file count
				if ((block->HEAD_FLAGS & 0xE0) != 0xE0) 
					fileCount++;
				writeRarBlock(rarInput, rarOutput, block);
			}
			else
			{
				rarInput->Seek(block->offsetData + block->dataLength, CFile::begin);
			}
			delete [] block->FILE_NAME;
			delete block;
		}
		retVal = true;
	}
	catch (CFileException* error){
		error->Delete();
	}
	catch (...){
		ASSERT(0);
	}

	// Tell the user how many files were recovered
	CString msg;	
	if (fileCount == 1)
		msg = GetResString(IDS_RECOVER_SINGLE);
	else
		msg.Format(GetResString(IDS_RECOVER_MULTIPLE), fileCount);
	AddLogLine(true, _T("%s"), msg);