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             : 
      20             : 
      21             : /** \file
      22             :  * \brief Database file implementation.
      23             :  *
      24             :  * Each table uses one or more files. Each file is handled by a dbfile
      25             :  * object and a corresponding set of blocks.
      26             :  */
      27             : 
      28             : // self
      29             : //
      30             : #include    "snapdatabase/block/block_free_block.h"
      31             : 
      32             : #include    "snapdatabase/block/block_header.h"
      33             : #include    "snapdatabase/database/table.h"
      34             : 
      35             : 
      36             : // last include
      37             : //
      38             : #include    <snapdev/poison.h>
      39             : 
      40             : 
      41             : 
      42             : namespace snapdatabase
      43             : {
      44             : 
      45             : 
      46             : 
      47             : namespace
      48             : {
      49             : 
      50             : 
      51             : 
      52             : // 'FREE'
      53             : constexpr struct_description_t g_description[] =
      54             : {
      55             :     define_description(
      56             :           FieldName("header")
      57             :         , FieldType(struct_type_t::STRUCT_TYPE_STRUCTURE)
      58             :         , FieldSubDescription(detail::g_block_header)
      59             :     ),
      60             :     define_description(
      61             :           FieldName("next_free_block")
      62             :         , FieldType(struct_type_t::STRUCT_TYPE_REFERENCE)
      63             :     ),
      64             :     // the rest of these blocks are all zeroes
      65             :     end_descriptions()
      66             : };
      67             : 
      68             : 
      69             : constexpr descriptions_by_version_t const g_descriptions_by_version[] =
      70             : {
      71             :     define_description_by_version(
      72             :         DescriptionVersion(0, 1),
      73             :         DescriptionDescription(g_description)
      74             :     ),
      75             :     end_descriptions_by_version()
      76             : };
      77             : 
      78             : 
      79             : 
      80             : }
      81             : // no name namespace
      82             : 
      83             : 
      84             : 
      85             : 
      86             : 
      87           1 : block_free_block::block_free_block(dbfile::pointer_t f, reference_t offset)
      88           1 :     : block(g_descriptions_by_version, f, offset)
      89             : {
      90           1 : }
      91             : 
      92             : 
      93           1 : reference_t block_free_block::get_next_free_block() const
      94             : {
      95           1 :     return static_cast<reference_t>(f_structure->get_uinteger("next_free_block"));
      96             : }
      97             : 
      98             : 
      99           0 : void block_free_block::set_next_free_block(reference_t offset)
     100             : {
     101           0 :     f_structure->set_uinteger("next_free_block", offset);
     102           0 : }
     103             : 
     104             : 
     105           0 : void block_free_block::clear_block()
     106             : {
     107           0 :     reference_t const offset(f_structure->get_size());
     108             : #ifdef _DEBUG
     109           0 :     if(offset == 0)
     110             :     {
     111           0 :         throw snapdatabase_logic_error("the structure of the block_free_block block cannot be dynamic.");
     112             :     }
     113             : #endif
     114           0 :     std::uint32_t const page_size(get_table()->get_page_size() - offset);
     115             : 
     116           0 :     memset(data(offset), 0, page_size);
     117           0 : }
     118             : 
     119             : 
     120             : 
     121             : } // namespace snapdatabase
     122             : // vim: ts=4 sw=4 et