Function FlatStream_BlockRead

3rdParty/StormLib/src/FileStream.cpp:1213–1255

}

static bool FlatStream_BlockRead(
    TBlockStream * pStream,                // Pointer to an open stream
    ULONGLONG StartOffset,
    ULONGLONG EndOffset,
    LPBYTE BlockBuffer,
    DWORD BytesNeeded,
    bool bAvailable)
{
    DWORD BytesToRead = (DWORD)(EndOffset - StartOffset);

    // The starting offset must be aligned to size of the block
    assert(pStream->FileBitmap != NULL);
    assert((StartOffset & (pStream->BlockSize - 1)) == 0);
    assert(StartOffset < EndOffset);

    // If the blocks are not available, we need to load them from the master
    // and then save to the mirror
    if(bAvailable == false)
    {
        // If we have no master, we cannot satisfy read request
        if(pStream->pMaster == NULL)
            return false;

        // Load the blocks from the master stream
        // Note that we always have to read complete blocks
        // so they get properly stored to the mirror stream
        if(!FileStream_Read(pStream->pMaster, &StartOffset, BlockBuffer, BytesToRead))
            return false;

        // Store the loaded blocks to the mirror file.
        // Note that this operation is not required to succeed
        if(pStream->BaseWrite(pStream, &StartOffset, BlockBuffer, BytesToRead))
            FlatStream_UpdateBitmap(pStream, StartOffset, EndOffset);

        return true;
    }
    else
    {
        if(BytesToRead > BytesNeeded)
            BytesToRead = BytesNeeded;
        return pStream->BaseRead(pStream, &StartOffset, BlockBuffer, BytesToRead);
    }
}

static void FlatStream_Close(TBlockStream * pStream)
{