mariadb-columnstore-engine/writeengine/index/we_freemgr.h

/* Copyright (C) 2014 InfiniDB, Inc.

   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; version 2 of
   the License.

   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., 51 Franklin Street, Fifth Floor, Boston,
   MA 02110-1301, USA. */

/******************************************************************************************
 * $Id: we_freemgr.h 33 2006-07-19 17:09:27Z mthomas $
 *
 ******************************************************************************************/
/** @file */

#pragma once

#include <stdlib.h>

#include <we_dbfileop.h>
#include <we_index.h>

/** Namespace WriteEngine */
namespace WriteEngine
{
/** Class FreeMgr */
class FreeMgr : public DbFileOp
{
 public:
  /**
   * @brief Constructor
   */
  FreeMgr();

  /**
   * @brief Default Destructor
   */
  ~FreeMgr();

  /**
   * @brief init free chains in a new index file
   */
  const int init(CommBlock& cb, const int freemgrType);

  /**
   * @brief Init free chains in a new file or an existing file
   * The start block is an FBO or an LBID depending on whether we are using BRM
   **/
  const int init(CommBlock& cb, DataBlock* blockZero, const int freemgrType, const IdxTreeGroupType chainType,
                 const int startBlock, const int numberBlocks);

  /**
   * @brief find a free segment and return ptr
   */
  const int assignSegment(CommBlock& cb, DataBlock* blockZero, const int freemgr_type,
                          const IdxTreeGroupType segmentType, IdxEmptyListEntry* assignPtr);

  /**
   * @brief put a free segment back into chain
   */
  const int releaseSegment(CommBlock& cb, DataBlock* blockZero, const int freemgr_type,
                           const IdxTreeGroupType segmentType, IdxEmptyListEntry* assignPtr);

  /**
   * @brief Map an FBO to LBID
   */
  const uint64_t mapLBID(CommBlock& cb, const uint64_t fbo, int& rc);

  /**
   * extendFreespace - ran out of space in one of the chains?
   * Add blocks via calls to BRM extent mgr and fseek the file to the end
   **/
  const int extendFreespace(CommBlock& cb, DataBlock* blockZero, const int freemgr_type);

  // private:

  /**
   * @brief Create sub block zero for use by free manager
   */
  const int initBlockzero(DataBlock* blockZero);

  /**
   * @brief Handle release of sub-blocks separately - sometimes a sub-block contains list entries and
   * sometimes it is a list entry
   */

  const int releaseSubblock(CommBlock& cb, WriteEngine::DataBlock*, int, WriteEngine::IdxEmptyListEntry*);

  /**
   * @brief Handle assignment of sub-blocks separately - sometimes a sub-block contains list entries and
   * sometimes it is a list entry
   */

  const int assignSubblock(CommBlock& cb, WriteEngine::DataBlock*, int, WriteEngine::IdxEmptyListEntry*);

  /**
   * Blank out the entries in the structure
   **/
  const void nullPtr(WriteEngine::IdxEmptyListEntry* assignPtr) const;

  const void printMemSubBlock(DataBlock* curBlock, const int sbid);

  inline const int calcPtrOffset(const int position) const
  {
    return 1 + position;
  }

  inline const int calcStatOffset(const int position) const
  {
    return 8 + position;
  }

  int initType;     // decide which algorithm to use to init the chains
  int allowExtend;  // allow file to be extended
};

}  // namespace WriteEngine