bool CZipCentralDir::RemoveDataDescr(bool bFromBuffer)
{
// this will not work if there are bytes before zip
CZipFileMapping fm;
char* pFile;
ZIP_SIZE_TYPE uSize;
if (bFromBuffer)
{
uSize = m_pStorage->m_uBytesInWriteBuffer;
pFile = m_pStorage->m_pWriteBuffer;
}
else
{
uSize = (ZIP_SIZE_TYPE)m_pStorage->m_pFile->GetLength();
// we cannot use CZipMemFile in multi-volume archive
// so it must be CZipFile
if (!fm.CreateMapping(static_cast<CZipFile*>(m_pStorage->m_pFile)))
return false;
pFile = fm.GetMappedMemory();
}
ZIP_SIZE_TYPE uOffsetToChange = 4;
ZIP_SIZE_TYPE uPosInBuffer = 0;
WORD uExtraHeaderLen;
ZIP_INDEX_TYPE uCount = (ZIP_INDEX_TYPE)m_pHeaders->GetSize();
for (ZIP_INDEX_TYPE i = 0; i < uCount; i++)
{
CZipFileHeader* pHeader = (*m_pHeaders)[(ZIP_ARRAY_SIZE_TYPE)i];
char* pSource = pFile + pHeader->m_uOffset;
if (pHeader->NeedsDataDescriptor())
uExtraHeaderLen = (WORD)(pHeader->IsEncrypted() ? 0 : 4);
else
{
uExtraHeaderLen = pHeader->GetDataDescriptorSize(true);
// removing data descriptor
pHeader->m_uFlag &= ~8;
// update local header:
// write modified flag in the local header
CBytesWriter::WriteBytes(pSource + 6, pHeader->m_uFlag);
pHeader->WriteSmallDataDescriptor(pSource + 14, false);
}
ZIP_SIZE_TYPE uToCopy = (i == (uCount - 1) ? uSize : (*m_pHeaders)[(ZIP_ARRAY_SIZE_TYPE)(i + 1)]->m_uOffset)
- pHeader->m_uOffset - uExtraHeaderLen;
if (uToCopy > 0)
// TODO: [postponed] the size_t limit on uToCopy, but creating such a big segment is unlikely (at least at the moment of writing)
memmove(pFile + uPosInBuffer, pSource, (size_t)uToCopy);
uPosInBuffer += uToCopy;
pHeader->m_uOffset -= uOffsetToChange;
uOffsetToChange += uExtraHeaderLen;
}
if (bFromBuffer)
m_pStorage->m_uBytesInWriteBuffer = (DWORD)uPosInBuffer;
else
{
m_pStorage->m_uBytesWritten = uPosInBuffer;
fm.RemoveMapping();
m_pStorage->m_pFile->SetLength((ZIP_FILE_USIZE)uPosInBuffer);
}
return true;
}
