log_postpone_cache.hpp

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/*
 * Copyright 2008 Search Solution Corporation
 * Copyright 2016 CUBRID Corporation
 *
 *  Licensed 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.
 *
 */

/*
 * log_postpone_cache.hpp - log postpone cache module
 */

#ifndef _LOG_POSTPONE_CACHE_HPP_
#define _LOG_POSTPONE_CACHE_HPP_

#include "log_lsa.hpp"
#include "log_record.hpp"
#include "mem_block.hpp"
#include "storage_common.h"

#include <array>

// forward declarations
struct log_tdes;
struct log_prior_node;

namespace cubthread
{
  class entry;
}

class log_postpone_cache
{
  public:
    log_postpone_cache ()
      : m_redo_data_buf ()
      , m_redo_data_offset (0)
      , m_is_redo_data_buf_full (false)
      , m_cursor (0)
      , m_cache_entries ()
    {
    }

    log_postpone_cache (log_postpone_cache &&other) = delete;
    log_postpone_cache (const log_postpone_cache &other) = delete;

    log_postpone_cache &operator= (log_postpone_cache &&other) = delete;
    log_postpone_cache &operator= (const log_postpone_cache &other) = delete;

    ~log_postpone_cache () = default;

    void reset ();

    void add_redo_data (const log_prior_node &node);
    void add_lsa (const log_lsa &lsa);
    bool do_postpone (cubthread::entry &thread_ref, const log_lsa &start_postpone_lsa);

  private:
    static const std::size_t MAX_CACHE_ENTRIES = 512;
    static const std::size_t REDO_DATA_MAX_SIZE = 100 * 1024;   // 100k
    static const std::size_t BUFFER_RESET_SIZE = 1024;

    class cache_entry
    {
      public:
    cache_entry ()
      : m_lsa ()
      , m_offset (0)
    {
      m_lsa.set_null ();
    }

    log_lsa m_lsa;
    std::size_t m_offset;
    };

    cubmem::extensible_block m_redo_data_buf;
    std::size_t m_redo_data_offset;
    bool m_is_redo_data_buf_full;

    std::size_t m_cursor;
    std::array<cache_entry, MAX_CACHE_ENTRIES> m_cache_entries;

    bool is_full () const;
};

#endif /* _LOG_POSTPONE_CACHE_HPP_ */