metadata.hpp

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/*
 * Copyright (c) 2014-2015, Hewlett-Packard Development Company, LP.
 * This program 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; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * HP designates this particular file as subject to the "Classpath" exception
 * as provided by HP in the LICENSE.txt file that accompanied this code.
 */
#ifndef FOEDUS_STORAGE_METADATA_HPP_
#define FOEDUS_STORAGE_METADATA_HPP_
#include <iosfwd>
#include <string>

#include "foedus/assert_nd.hpp"
#include "foedus/cxx11.hpp"
#include "foedus/assorted/fixed_string.hpp"
#include "foedus/externalize/externalizable.hpp"
#include "foedus/storage/fwd.hpp"
#include "foedus/storage/storage_id.hpp"

namespace foedus {
namespace storage {
struct Metadata {
  struct SnapshotThresholds {
    SnapshotThresholds() : snapshot_trigger_threshold_(0), snapshot_keep_threshold_(0) {}
    uint32_t        snapshot_trigger_threshold_;
    uint32_t        snapshot_keep_threshold_;
  };

  Metadata()
    : id_(0), type_(kInvalidStorage), name_(""), root_snapshot_page_id_(0), snapshot_thresholds_() {
  }
  Metadata(StorageId id, StorageType type, const StorageName& name)
    : id_(id), type_(type), name_(name), root_snapshot_page_id_(0), snapshot_thresholds_() {}
  Metadata(
    StorageId id,
    StorageType type,
    const StorageName& name,
    SnapshotPagePointer root_snapshot_page_id)
    : id_(id),
    type_(type),
    name_(name),
    root_snapshot_page_id_(root_snapshot_page_id),
    snapshot_thresholds_() {}

  static std::string describe(const Metadata& metadata);

  bool keeps_all_volatile_pages() const {
    return snapshot_thresholds_.snapshot_keep_threshold_ == 0xFFFFFFFFU;
  }

  StorageId       id_;
  StorageType     type_;
  StorageName     name_;
  SnapshotPagePointer root_snapshot_page_id_;

  SnapshotThresholds  snapshot_thresholds_;
};

struct MetadataSerializer : public virtual externalize::Externalizable {
  MetadataSerializer() : data_(CXX11_NULLPTR) {}
  explicit MetadataSerializer(Metadata *data) : data_(data) {}
  virtual ~MetadataSerializer() {}

  ErrorStack load_base(tinyxml2::XMLElement* element);
  ErrorStack save_base(tinyxml2::XMLElement* element) const;

  static ErrorStack load_all_storages_from_xml(
    storage::StorageId largest_storage_id,
    tinyxml2::XMLElement* element,
    StorageControlBlock* blocks);
  static ErrorStack save_all_storages_to_xml(
    storage::StorageId largest_storage_id,
    tinyxml2::XMLElement* element,
    StorageControlBlock* blocks);

  Metadata *data_;
};

}  // namespace storage
}  // namespace foedus
#endif  // FOEDUS_STORAGE_METADATA_HPP_