// if user wants result to buffer?
void QXpkLib::getToBuffer(QByteArray &Array)
{
CIOBuffer *pOut = m_pMaster->getResult();
// reserve out-buffer and copy what we have
Array.resize(pOut->GetCurrentPos());
::memcpy(Array.data(), pOut->GetBegin(), pOut->GetCurrentPos());
}
//////////////////
//
// XPK fileformat:
// chunk-based, crunched data in chunks
//
// Chunk format:
// * chunk header
// - 1 byte for chunk type
// - 1 byte for chunk header checksum ?
// - 2 bytes for chunk checksum
// - 2/4 bytes for chunk (compressed) length
// - 2/4 bytes for uncompressed length?
// * chunk data
// - amount of packed data given in chunk header..
//
// Note: chunk header may have different size in different file
// according to flags (if "long" sizes are used for chunks).
//
//
void XpkTags::ReadChunks(CIOBuffer &Buffer)
{
m_pFirst = new XpkChunk();
m_pFirst->m_nDataOffset = Buffer.GetCurrentPos();
XpkChunk *pCurrent = m_pFirst;
while (Buffer.IsEnd() == false)
{
bool isValidHeader = false;
if (m_streamHeader.xsh_Flags & XPKSTREAMF_LONGHEADERS)
{
XpkChunkHdrLong *pHdr = (XpkChunkHdrLong*)Buffer.GetAtCurrent();
pCurrent->m_Type = pHdr->xchl_Type;
pCurrent->m_HChecksum = pHdr->xchl_HChk;
pCurrent->m_ChunkChecksum = Swap2(pHdr->xchl_CChk);
pCurrent->m_ChunkLength = Swap4(pHdr->xchl_CLen);
pCurrent->m_UnLen = Swap4(pHdr->xchl_ULen);
pCurrent->m_nDataOffset += sizeof(XpkChunkHdrLong);
isValidHeader = verifyHeaderLong(pHdr);
}
else
{
XpkChunkHdrWord *pHdr = (XpkChunkHdrWord*)Buffer.GetAtCurrent();
pCurrent->m_Type = pHdr->xchw_Type;
pCurrent->m_HChecksum = pHdr->xchw_HChk;
pCurrent->m_ChunkChecksum = Swap2(pHdr->xchw_CChk);
pCurrent->m_ChunkLength = Swap2(pHdr->xchw_CLen);
pCurrent->m_UnLen = Swap2(pHdr->xchw_ULen);
pCurrent->m_nDataOffset += sizeof(XpkChunkHdrWord);
isValidHeader = verifyHeaderWord(pHdr);
}
// TODO: need header checksum verification somewhere around here..
if (isValidHeader == false)
{
// TODO: exception or skip ?
}
if (pCurrent->m_Type != XPKCHUNK_RAW
&& pCurrent->m_Type != XPKCHUNK_PACKED
&& pCurrent->m_Type != XPKCHUNK_END)
{
// TODO: exception or skip ?
}
// move to actual data of chunk (according to chunk header size)
Buffer.SetCurrentPos(pCurrent->m_nDataOffset);
// "end-of-file" chunk? (empty)
if (pCurrent->m_Type == XPKCHUNK_END)
{
return;
}
// TODO:
// .. process chunk
// -> walkthrough in XPK-master now..
// offset to start of next chunk:
// start of data in current + size of data in current
size_t nNextChunkOffset = pCurrent->m_nDataOffset + pCurrent->m_ChunkLength;
Buffer.SetCurrentPos(nNextChunkOffset);
pCurrent->m_pNext = new XpkChunk(pCurrent);
pCurrent->m_pNext->m_nDataOffset = nNextChunkOffset;
pCurrent = pCurrent->m_pNext;
}
}
//////////////////
//
// XPK fileformat:
// chunk-based, crunched data in chunks
//
// File header:
// starts as common IFF-style header:
// - 4-byte ID, 'XPKF'
// - 4-byte int for filesize minus header (8)
// - 4-byte sub-type (cruncher-ID) e.g. 'SQSH'
// - 4-byte int for total uncompressed length ?
// - first 16-bytes of original file
// - 1 byte for flags
// - 1 byte for header checksum ?
// - 1 byte for minor version of cruncher/library ?
// - actually version required of sub-library..
// - 1 byte for major version of cruncher/library ?
//
bool XpkTags::ReadStreamHeader(CIOBuffer &Buffer)
{
// should have enough data to actually parse file header
if (Buffer.GetSize() < sizeof(XpkStreamHeader))
{
return false;
}
if (isXpkFile(Buffer.GetBegin()) == false)
{
return false;
}
Buffer.SetCurrentPos(0); // start at beginning if not already..
// set default
m_formatType = XPKMODE_UPSTD;
// "XPKF", 0x58504b46 (XPK_COOKIE, magic number)
// note: support also XFD-packed files? ("XFDD")
m_streamHeader.xsh_PackID = GetULong(Buffer.GetNext(4));
if (m_streamHeader.xsh_PackID != MakeTag("XPKF"))
// this too ? && m_streamHeader.xsh_PackID != MakeTag("XFDD"))
{
return false;
}
// file length without IFF header (type+length = 8) ?
m_streamHeader.xsh_CompressedLen = GetULong(Buffer.GetNext(4));
// keep packer type as type name/ID,
// just access as-is
m_typeName.assign((char*)Buffer.GetAtCurrent(), 4);
// packer type, e.g. "SQSH", "NUKE", "RLEN"..
m_streamHeader.xsh_PackerType = GetULong(Buffer.GetNext(4));
// TODO: check supported types..? if != MakeTag()..
// -> caller/parent should do (knows libraries..)
// uncompressed length?
m_streamHeader.xsh_UnpackedLen = GetULong(Buffer.GetNext(4));
// first 16 bytes of original file
::memcpy(m_streamHeader.xsh_Initial, Buffer.GetNext(16), 16);
// flags
m_streamHeader.xsh_Flags = Buffer.GetNextByte();
/*
// also check "XFDD", 0x58464444 in file ID?
if (m_streamHeader.xsh_Flags & XMF_XFD && m_streamHeader.xsh_PackID == MakeTag("XFDD"))
{
m_formatType = XPKMODE_UPXFD;
}
if (m_streamHeader.xsh_Flags & XMF_PASSTHRU)
{
// unpacked?
m_formatType = XPKMODE_UPUP;
}
if (m_streamHeader.xsh_Flags & XPKSTREAMF_PASSWORD)
{
// password-protected file?
}
*/
// ..no idea.. header checksum?
m_streamHeader.xsh_HeaderChk = Buffer.GetNextByte();
// minor&major version of XPK master/cruncher?
m_streamHeader.xsh_SubVrs = Buffer.GetNextByte(); // sub-library version required?
m_streamHeader.xsh_MasVrs = Buffer.GetNextByte();
// TODO: remove later, debug-test..
if (Buffer.GetCurrentPos() != sizeof(XpkStreamHeader))
{
throw IOException("Read size does not match stream-header size");
}
// non-zero header checksum? (note where doing checksumming..)
if (hchecksum(Buffer.GetBegin(), sizeof(XpkStreamHeader)) != 0)
{
throw ArcException("Header checksum error", m_streamHeader.xsh_HeaderChk);
}
// has extended header?
if (m_streamHeader.xsh_Flags & XPKSTREAMF_EXTHEADER)
{
// size of extended header if present?
m_extHeaderLen = GetUWord(Buffer.GetNext(2));
/*
// this done above..
if(!hookread(xbuf, XIO_READ, &exthlen, sizeof(UWORD)))
goto Abort; -> exception
// no read, just skip it??
if(!hookread(xbuf, XIO_READ, NULL, exthlen))
goto Abort; -> exception
// later it is read anyway, why not just directly when detected?
*/
// increment by length-field size anyway..
m_extHeaderLen += sizeof(uint16_t); /* for unwinding while XpkExamine */
// note: increase buffer position by size of extended header?
}
// header parsed, should be valid file?
return true;
}
