Function PIO_init_data

src/jrd/os/win32/winnt.cpp:425–495

USHORT PIO_init_data(thread_db* tdbb, jrd_file* main_file, FbStatusVector* status_vector,
					 ULONG startPage, USHORT initPages)
{
/**************************************
 *
 *	P I O _ i n i t _ d a t a
 *
 **************************************
 *
 * Functional description
 *	Initialize tail of file with zeros
 *
 **************************************/
	const char* const zero_buff = zeros().getBuffer();
	const FB_SIZE_T zero_buff_size = zeros().getSize();

	Database* const dbb = tdbb->getDatabase();

	EngineCheckout cout(tdbb, FB_FUNCTION, EngineCheckout::UNNECESSARY);
	FileExtendLockGuard extLock(main_file->fil_ext_lock, false);

	// Fake buffer, used in seek_file. Page space ID doesn't matter there
	// as we already know file to work with
	BufferDesc bdb(dbb->dbb_bcb);
	bdb.bdb_page = PageNumber(0, startPage);

	OVERLAPPED overlapped;
	jrd_file* file = seek_file(main_file, &bdb, &overlapped);

	if (!file)
		return 0;

	if (file->fil_min_page + 8 > startPage)
		return 0;

	USHORT leftPages = initPages;
	const ULONG initBy = MIN(file->fil_max_page - startPage, leftPages);
	if (initBy < leftPages)
		leftPages = initBy;

	for (ULONG i = startPage; i < startPage + initBy; )
	{
		bdb.bdb_page = PageNumber(0, i);
		USHORT write_pages = zero_buff_size / dbb->dbb_page_size;
		if (write_pages > leftPages)
			write_pages = leftPages;

		jrd_file* file1 = seek_file(main_file, &bdb, &overlapped);
		fb_assert(file1 == file);

		const DWORD to_write = (DWORD) write_pages * dbb->dbb_page_size;
		DWORD written;
		BOOL ret = WriteFile(file->fil_desc, zero_buff, to_write, &written, &overlapped);
		if (!ret)
		{
			if (GetLastError() == ERROR_IO_PENDING)
				ret = GetOverlappedResult(file->fil_desc, &overlapped, &written, TRUE);
		}