be/src/vec/io/var_int.h

// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.

#pragma once

#include "vec/common/string_buffer.hpp"
#include "vec/core/types.h"

namespace doris::vectorized {
/** Write Int64 in variable length format (base128) */
template <typename OUT>
void write_var_int(Int64 x, OUT& ostr) {
    ostr.write_var_uint(static_cast<UInt64>((x << 1) ^ (x >> 63)));
}

/** Read Int64, written in variable length format (base128) */
template <typename IN>
void read_var_int(Int64& x, IN& istr) {
    istr.read_var_uint(*reinterpret_cast<UInt64*>(&x));
    x = (static_cast<UInt64>(x) >> 1) ^ -(x & 1);
}

} // namespace doris::vectorized