presto-orc/src/main/java/io/prestosql/orc/stream/LongDecode.java/LongDecode/readUnsignedVInt
class LongDecode:    private static long readUnsignedVInt(OrcInputStream inputStream)
            throws IOException
    {
        long result = 0;
        int offset = 0;
        long b;
        do {
            b = inputStream.read();
            if (b == -1) {
                throw new OrcCorruptionException(inputStream.getOrcDataSourceId(), "EOF while reading unsigned vint");
            }
            result |= (b & 0b0111_1111) << offset;
            offset += 7;
        }
        while ((b & 0b1000_0000) != 0);
        return result;
    }