Function AllocateSectorChecksums

3rdParty/StormLib/src/SBaseCommon.cpp:1257–1332

}

int AllocateSectorChecksums(TMPQFile * hf, bool bLoadFromFile)
{
    TMPQArchive * ha = hf->ha;
    TFileEntry * pFileEntry = hf->pFileEntry;
    ULONGLONG RawFilePos;
    DWORD dwCompressedSize = 0;
    DWORD dwExpectedSize;
    DWORD dwCrcOffset;                      // Offset of the CRC table, relative to file offset in the MPQ
    DWORD dwCrcSize;

    // Caller of AllocateSectorChecksums must ensure these
    assert(hf->SectorChksums == NULL);
    assert(hf->SectorOffsets != NULL);
    assert(hf->pFileEntry != NULL);
    assert(hf->ha != NULL);

    // Single unit files don't have sector checksums
    if(pFileEntry->dwFlags & MPQ_FILE_SINGLE_UNIT)
        return ERROR_SUCCESS;

    // Caller must ensure that we are only called when we have sector checksums
    assert(pFileEntry->dwFlags & MPQ_FILE_SECTOR_CRC);

    //
    // Older MPQs store an array of CRC32's after
    // the raw file data in the MPQ.
    //
    // In newer MPQs, the (since Cataclysm BETA) the (attributes) file
    // contains additional 32-bit values beyond the sector table.
    // Their number depends on size of the (attributes), but their
    // meaning is unknown. They are usually zeroed in retail game files,
    // but contain some sort of checksum in BETA MPQs
    //

    // Does the size of the file table match with the CRC32-based checksums?
    dwExpectedSize = (hf->dwSectorCount + 2) * sizeof(DWORD);
    if(hf->SectorOffsets[0] != 0 && hf->SectorOffsets[0] == dwExpectedSize)
    {
        // If we are not loading from the MPQ file, we just allocate the sector table
        // In that case, do not check any sizes
        if(bLoadFromFile == false)
        {
            hf->SectorChksums = STORM_ALLOC(DWORD, hf->dwSectorCount);
            if(hf->SectorChksums == NULL)
                return ERROR_NOT_ENOUGH_MEMORY;

            // Fill the checksum table with zeros
            memset(hf->SectorChksums, 0, hf->dwSectorCount * sizeof(DWORD));
            return ERROR_SUCCESS;
        }
        else
        {
            // Is there valid size of the sector checksums?
            if(hf->SectorOffsets[hf->dwSectorCount + 1] >= hf->SectorOffsets[hf->dwSectorCount])
                dwCompressedSize = hf->SectorOffsets[hf->dwSectorCount + 1] - hf->SectorOffsets[hf->dwSectorCount];

            // Ignore cases when the length is too small or too big.
            if(dwCompressedSize < sizeof(DWORD) || dwCompressedSize > hf->dwSectorSize)