static SRes LookInStream_SeekRead_ForArc(ILookInStream *stream, UInt64 offset, void *buf, size_t size)
{
RINOK(LookInStream_SeekTo(stream, offset));
return LookInStream_Read(stream, buf, size);
/* return LookInStream_Read2(stream, buf, size, SZ_ERROR_NO_ARCHIVE); */
}
static SRes SzArEx_Open2(
CSzArEx *p,
ILookInStream *inStream,
ISzAlloc *allocMain,
ISzAlloc *allocTemp)
{
Byte header[k7zStartHeaderSize];
Int64 startArcPos;
UInt64 nextHeaderOffset, nextHeaderSize;
size_t nextHeaderSizeT;
UInt32 nextHeaderCRC;
CBuf buffer;
SRes res;
startArcPos = 0;
RINOK(inStream->Seek(inStream, &startArcPos, SZ_SEEK_CUR));
RINOK(LookInStream_Read2(inStream, header, k7zStartHeaderSize, SZ_ERROR_NO_ARCHIVE));
if (!TestSignatureCandidate(header))
return SZ_ERROR_NO_ARCHIVE;
if (header[6] != k7zMajorVersion)
return SZ_ERROR_UNSUPPORTED;
nextHeaderOffset = GetUi64(header + 12);
nextHeaderSize = GetUi64(header + 20);
nextHeaderCRC = GetUi32(header + 28);
p->startPosAfterHeader = startArcPos + k7zStartHeaderSize;
if (CrcCalc(header + 12, 20) != GetUi32(header + 8))
return SZ_ERROR_CRC;
nextHeaderSizeT = (size_t)nextHeaderSize;
if (nextHeaderSizeT != nextHeaderSize)
return SZ_ERROR_MEM;
if (nextHeaderSizeT == 0)
return SZ_OK;
if (nextHeaderOffset > nextHeaderOffset + nextHeaderSize ||
nextHeaderOffset > nextHeaderOffset + nextHeaderSize + k7zStartHeaderSize)
return SZ_ERROR_NO_ARCHIVE;
{
Int64 pos = 0;
RINOK(inStream->Seek(inStream, &pos, SZ_SEEK_END));
if ((UInt64)pos < startArcPos + nextHeaderOffset ||
(UInt64)pos < startArcPos + k7zStartHeaderSize + nextHeaderOffset ||
(UInt64)pos < startArcPos + k7zStartHeaderSize + nextHeaderOffset + nextHeaderSize)
return SZ_ERROR_INPUT_EOF;
}
RINOK(LookInStream_SeekTo(inStream, startArcPos + k7zStartHeaderSize + nextHeaderOffset));
if (!Buf_Create(&buffer, nextHeaderSizeT, allocTemp))
return SZ_ERROR_MEM;
res = LookInStream_Read(inStream, buffer.data, nextHeaderSizeT);
if (res == SZ_OK)
{
res = SZ_ERROR_ARCHIVE;
if (CrcCalc(buffer.data, nextHeaderSizeT) == nextHeaderCRC)
{
CSzData sd;
UInt64 type;
sd.Data = buffer.data;
sd.Size = buffer.size;
res = SzReadID(&sd, &type);
if (res == SZ_OK)
{
if (type == k7zIdEncodedHeader)
{
CBuf outBuffer;
Buf_Init(&outBuffer);
res = SzReadAndDecodePackedStreams(inStream, &sd, &outBuffer, p->startPosAfterHeader, allocTemp);
if (res != SZ_OK)
Buf_Free(&outBuffer, allocTemp);
else
{
Buf_Free(&buffer, allocTemp);
buffer.data = outBuffer.data;
buffer.size = outBuffer.size;
sd.Data = buffer.data;
sd.Size = buffer.size;
res = SzReadID(&sd, &type);
}
}
}
if (res == SZ_OK)
{
if (type == k7zIdHeader)
res = SzReadHeader(p, &sd, allocMain, allocTemp);
else
res = SZ_ERROR_UNSUPPORTED;
}
}
}
Buf_Free(&buffer, allocTemp);
return res;
}
