ZipStreamBuf::ZipStreamBuf(std::ostream& ostr, ZipLocalFileHeader& fileEntry, bool reposition):
Poco::BufferedStreamBuf(STREAM_BUFFER_SIZE, std::ios::out),
_pIstr(0),
_pOstr(&ostr),
_ptrBuf(),
_ptrOBuf(),
_ptrHelper(),
_ptrOHelper(),
_crc32(Poco::Checksum::TYPE_CRC32),
_expectedCrc32(0),
_checkCRC(false),
_bytesWritten(0),
_pHeader(&fileEntry)
{
if (fileEntry.isEncrypted())
throw Poco::NotImplementedException("Encryption not supported");
if (fileEntry.isDirectory())
{
// only header, no payload, zero crc
fileEntry.setSearchCRCAndSizesAfterData(false);
fileEntry.setCompressedSize(0);
fileEntry.setUncompressedSize(0);
fileEntry.setCRC(0);
std::string header = fileEntry.createHeader();
ostr.write(header.c_str(), static_cast<std::streamsize>(header.size()));
}
else
{
fileEntry.setSearchCRCAndSizesAfterData(!reposition);
if (fileEntry.getCompressionMethod() == ZipCommon::CM_DEFLATE)
{
int level = Z_DEFAULT_COMPRESSION;
if (fileEntry.getCompressionLevel() == ZipCommon::CL_FAST || fileEntry.getCompressionLevel() == ZipCommon::CL_SUPERFAST)
level = Z_BEST_SPEED;
else if (fileEntry.getCompressionLevel() == ZipCommon::CL_MAXIMUM)
level = Z_BEST_COMPRESSION;
// ignore the zlib init string which is of size 2 and also ignore the 4 byte adler32 value at the end of the stream!
_ptrOHelper = new PartialOutputStream(*_pOstr, 2, 4, false);
_ptrOBuf = new Poco::DeflatingOutputStream(*_ptrOHelper, DeflatingStreamBuf::STREAM_ZLIB, level);
}
else if (fileEntry.getCompressionMethod() == ZipCommon::CM_STORE)
{
_ptrOHelper = new PartialOutputStream(*_pOstr, 0, 0, false);
_ptrOBuf = new PartialOutputStream(*_ptrOHelper, 0, 0, false);
}
else throw Poco::NotImplementedException("Unsupported compression method");
// now write the header to the ostr!
std::string header = fileEntry.createHeader();
ostr.write(header.c_str(), static_cast<std::streamsize>(header.size()));
}
}
