private Collection<Long> readListOfNoteIds() {
		final File idsFile = getIdsFile();
		if( !idsFile.exists() || !idsFile.canRead() ) {
			return Collections.emptyList();
		}

		BufferedReader r = null;
		try {
			r = FileHelper.getBufferedUtf8FileReader( idsFile );
			return readListOfNoteIdsFromReader( r );
		}
		catch( final IOException e ) {
			throw new RuntimeException( e );
		}
		finally {
			FileHelper.closeIgnoreException( r );
		}
	}