/* 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 */

#ifndef _WE_FREEMGR_H_
#define _WE_FREEMGR_H_

#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
};

} //end of namespace
#endif // _WE_FREEMGR_H_