Method beginBackup

src/jrd/nbak.cpp:249–366

Initialize and open difference file for writing

// Initialize and open difference file for writing
void BackupManager::beginBackup(thread_db* tdbb)
{
	NBAK_TRACE(("beginBackup"));

	SET_TDBB(tdbb);

	// Check for raw device
	if ((!explicit_diff_name) && database->onRawDevice()) {
		ERR_post(Arg::Gds(isc_need_difference));
	}

	MasterGuard masterGuard(*this);

	WIN window(HEADER_PAGE_NUMBER);

	StateWriteGuard stateGuard(tdbb, &window);
	Ods::header_page* header = (Ods::header_page*) window.win_buffer;

	// Check state
	if (backup_state != Ods::hdr_nbak_normal)
	{
		NBAK_TRACE(("begin backup - invalid state %d", backup_state));
		stateGuard.setSuccess();
		return;
	}

	// Check crypt state
	if (header->hdr_flags & Ods::hdr_crypt_process)
	{
		NBAK_TRACE(("begin backup - crypt thread runs"));
		stateGuard.setSuccess();
		ERR_post(Arg::Gds(isc_wish_list) << Arg::Gds(isc_random) <<
			"Cannot begin backup: please wait for crypt thread completion");
	}

	try
	{
		// Create file
		NBAK_TRACE(("Creating difference file %s", diff_name.c_str()));
		diff_file = PIO_create(tdbb, diff_name, true, false);
	}
	catch (const Firebird::Exception&)
	{
		// no reasons to set it to unknown if we just failed to create difference file
		stateGuard.setSuccess();
		backup_state = Ods::hdr_nbak_normal;
		throw;
	}

	{ // logical scope
		if (database->dbb_flags & (DBB_force_write | DBB_no_fs_cache))
		{
			setForcedWrites(database->dbb_flags & DBB_force_write,
							database->dbb_flags & DBB_no_fs_cache);
		}

#ifdef UNIX
		// adjust difference file access rights to make it match main DB ones