MetaLogEntity.h

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/* -*- 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_MetaLogEntity_h
#define Hypertable_Lib_MetaLogEntity_h

#include "MetaLogEntityHeader.h"

#include <Common/Logger.h>
#include <Common/Serializable.h>

#include <boost/algorithm/string.hpp>

#include <iostream>
#include <memory>
#include <mutex>

namespace Hypertable {

  namespace MetaLog {

    class Reader;
    class Writer;

    class Entity : public std::enable_shared_from_this<Entity>, public Serializable {
    public:

      Entity(int32_t type);

      Entity(const EntityHeader &header_);

      virtual ~Entity() { }

      using Serializable::decode;

      virtual void decode(const uint8_t **bufp, size_t *remainp,
                          uint16_t definition_version) {
        HT_ASSERT(!"Not Implemented");
      }

      void lock() { m_mutex.lock(); }

      void unlock() { m_mutex.unlock(); }

      void mark_for_removal() {
        header.flags |= EntityHeader::FLAG_REMOVE;
        header.length = header.checksum = 0;
      }

      bool marked_for_removal() {
        return (header.flags & EntityHeader::FLAG_REMOVE) != 0;
      }

      virtual const std::string name() = 0;

      int64_t id() const { return header.id; }

      virtual void display(std::ostream &os) { }

      friend std::ostream &operator <<(std::ostream &os, Entity &entity);
      friend class Reader;
      friend class Writer;

    protected:

      void encode_entry(uint8_t **bufp);

      mutable std::mutex m_mutex;

      EntityHeader header;
    };

    typedef std::shared_ptr<Entity> EntityPtr;

    inline std::ostream &
    operator <<(std::ostream &os, Entity &entity) {
      os << "{MetaLog::Entity " << entity.name() << " header={";
      entity.header.display(os);
      os << "} payload={";
      entity.display(os);
      os << "}";
      return os;
    }

    namespace EntityType {
      enum {
        RECOVER = 0x00000001 
      };
    }

    class EntityRecover : public Entity {
    public:

      EntityRecover() : Entity(EntityType::RECOVER) { }

      size_t encoded_length() const override { return 0; }

      void encode(uint8_t **bufp) const override { }

      void decode(const uint8_t **bufp, size_t *remainp) override {}

      void decode(const uint8_t **bufp, size_t *remainp,
                  uint16_t definition_version) override {}

      const std::string name() override { return "Recover"; }

    private:

      uint8_t encoding_version() const override { return 0; }

      size_t encoded_length_internal() const override { return 0; }

      void encode_internal(uint8_t **bufp) const override { }

      void decode_internal(uint8_t version, const uint8_t **bufp,
                           size_t *remainp) override { }
      
    };
  }
}

#endif // Hypertable_Lib_MetaLogEntity_h