ob_file_reader.h

/* Copyright (c) 2021 OceanBase and/or its affiliates. All rights reserved.
miniob is licensed under Mulan PSL v2.
You can use this software according to the terms and conditions of the Mulan PSL v2.
You may obtain a copy of Mulan PSL v2 at:
         http://license.coscl.org.cn/MulanPSL2
THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
See the Mulan PSL v2 for more details. */
 
#pragma once
 
#include "common/lang/fstream.h"
#include "common/lang/memory.h"
#include "common/lang/sstream.h"
#include "common/lang/string.h"
#include "common/sys/rc.h"
#include "common/lang/mutex.h"
 
namespace oceanbase {
 
class ObFileReader
{
public:
  ObFileReader(const string &filename) : filename_(filename) {}
 
  ~ObFileReader();
 
  RC open_file();
 
  void close_file();
 
  string read_pos(uint32_t pos, uint32_t size);
 
  uint32_t file_size();
 
  static unique_ptr<ObFileReader> create_file_reader(const string &filename);
 
private:
  string filename_;
 
  int fd_ = -1;
};
 
}  // namespace oceanbase