Function PartStream_Open

3rdParty/StormLib/src/FileStream.cpp:1778–1830

static TFileStream * PartStream_Open(const TCHAR * szFileName, DWORD dwStreamFlags)
{
    TBlockStream * pStream;

    // Create new empty stream
    pStream = (TBlockStream *)AllocateFileStream(szFileName, sizeof(TBlockStream), dwStreamFlags);
    if(pStream == NULL)
        return NULL;

    // Do we have a master stream?
    if(pStream->pMaster != NULL)
    {
        if(!PartStream_CreateMirror(pStream))
        {
            FileStream_Close(pStream);
            SetLastError(ERROR_FILE_NOT_FOUND);
            return NULL;
        }
    }
    else
    {
        // Attempt to open the base stream
        if(!pStream->BaseOpen(pStream, pStream->szFileName, dwStreamFlags))
        {
            FileStream_Close(pStream);
            return NULL;
        }

        // Load the part stream block map
        if(!PartStream_LoadBitmap(pStream))
        {
            FileStream_Close(pStream);
            SetLastError(ERROR_BAD_FORMAT);
            return NULL;
        }
    }

    // Set the stream position to zero. Stream size is already set
    assert(pStream->StreamSize != 0);
    pStream->StreamPos = 0;
    pStream->dwFlags |= STREAM_FLAG_READ_ONLY;

    // Set new function pointers
    pStream->StreamRead    = (STREAM_READ)BlockStream_Read;
    pStream->StreamGetPos  = BlockStream_GetPos;
    pStream->StreamGetSize = BlockStream_GetSize;
    pStream->StreamClose   = (STREAM_CLOSE)PartStream_Close;

    // Supply the block functions
    pStream->BlockCheck    = (BLOCK_CHECK)PartStream_BlockCheck;
    pStream->BlockRead     = (BLOCK_READ)PartStream_BlockRead;
    return pStream;
}

//-----------------------------------------------------------------------------
// Local functions - MPQE stream support