presto-rcfile/src/main/java/io/prestosql/rcfile/RcFileDecoderUtils.java/RcFileDecoderUtils/readVInt
class RcFileDecoderUtils:    public static long readVInt(Slice slice, int start, int length)
    {
        if (length == 1) {
            return slice.getByte(start);
        }

        return readVIntInternal(slice, start, length);
    }