Line data    Source code

       1             : // Copyright (c) 2019  Made to Order Software Corp.  All Rights Reserved
       2             : //
       3             : // https://snapwebsites.org/project/snapdatabase
       4             : // contact@m2osw.com
       5             : //
       6             : // This program is free software; you can redistribute it and/or modify
       7             : // it under the terms of the GNU General Public License as published by
       8             : // the Free Software Foundation; either version 2 of the License, or
       9             : // (at your option) any later version.
      10             : //
      11             : // This program is distributed in the hope that it will be useful,
      12             : // but WITHOUT ANY WARRANTY; without even the implied warranty of
      13             : // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      14             : // GNU General Public License for more details.
      15             : //
      16             : // You should have received a copy of the GNU General Public License along
      17             : // with this program; if not, write to the Free Software Foundation, Inc.,
      18             : // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
      19             : #pragma once
      20             : 
      21             : 
      22             : /** \file
      23             :  * \brief Block used to list data blocks with free space.
      24             :  *
      25             :  */
      26             : 
      27             : // self
      28             : //
      29             : #include    "snapdatabase/data/structure.h"
      30             : 
      31             : 
      32             : 
      33             : namespace snapdatabase
      34             : {
      35             : 
      36             : 
      37             : 
      38             : namespace detail
      39             : {
      40             : class block_free_space_impl;
      41             : }
      42             : 
      43             : 
      44             : // bits 0 to 7 are reserved by the block_free_space
      45             : constexpr uint32_t              ALLOCATED_SPACE_FLAG_MOVED      = 0x000100;
      46             : constexpr uint32_t              ALLOCATED_SPACE_FLAG_DELETED    = 0x000200;
      47             : 
      48             : 
      49           0 : struct free_space_t
      50             : {
      51             :     block::pointer_t            f_block = block::pointer_t();
      52             :     reference_t                 f_reference = 0;
      53             :     uint32_t                    f_size = 0;
      54             : };
      55             : 
      56             : 
      57             : class block_free_space
      58             :     : public block
      59             : {
      60             : public:
      61             :     typedef std::shared_ptr<block_free_space>       pointer_t;
      62             : 
      63             :                                 block_free_space(dbfile::pointer_t f, reference_t offset);
      64             :                                 ~block_free_space();
      65             : 
      66             :     free_space_t                get_free_space(uint32_t minimum_size);
      67             :     void                        release_space(reference_t offset);
      68             : 
      69             :     static bool                 get_flag(data_t ptr, uint32_t flag);
      70             :     static void                 set_flag(data_t ptr, uint32_t flag);
      71             :     static void                 clear_flag(data_t ptr, uint32_t flag);
      72             : 
      73             : private:
      74             :     std::unique_ptr<detail::block_free_space_impl>
      75             :                                 f_impl;
      76             : };
      77             : 
      78             : 
      79             : 
      80             : } // namespace snapdatabase
      81             : // vim: ts=4 sw=4 et