MetaLogReader.h

Go to the documentation of this file.

/* -*- c++ -*-
 * Copyright (C) 2007-2015 Hypertable, Inc.
 *
 * This file is part of Hypertable.
 *
 * Hypertable is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; version 3 of the
 * License, or any later version.
 *
 * Hypertable is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

#ifndef Hypertable_Lib_MetaLogReader_h
#define Hypertable_Lib_MetaLogReader_h

#include "MetaLogDefinition.h"

#include <Common/Filesystem.h>

#include <deque>
#include <map>
#include <memory>
#include <vector>

namespace Hypertable {

  namespace MetaLog {

    class Reader {

    public:

      enum Flags {
        LOAD_ALL_ENTITIES=1
      };

      Reader(FilesystemPtr &fs, DefinitionPtr &definition, int flags=0);

      Reader(FilesystemPtr &fs, DefinitionPtr &definition, const std::string &path, int flags=0);

      void get_entities(std::vector<EntityPtr> &entities);

      void get_all_entities(std::vector<EntityPtr> &entities);

      void reload();

      int32_t next_file_number() {
        return m_file_nums.empty() ? 0 : m_file_nums.front() + 1;
      }

      void load_file(const std::string &fname);

      uint16_t version() { return m_version; }

    private:

      void verify_backup(int32_t file_num);

      void read_header(int fd, int64_t *offsetp);

      FilesystemPtr m_fs;

      MetaLog::DefinitionPtr m_definition;

      std::string m_path;

      int m_flags;

      std::deque<int32_t> m_file_nums;

      std::map<EntityHeader, EntityPtr> m_entity_map;

      std::vector<EntityPtr> m_entities;

      std::string m_backup_path;

      uint16_t m_version;
    };

    typedef std::shared_ptr<Reader> ReaderPtr;

  }
}

#endif // Hypertable_Lib_MetaLogReader_h