LCOV - code coverage report
Current view: top level - home/snapwebsites/snapcpp/snapwebsites/snapdatabase/snapdatabase/block - block_schema.cpp (source / functions) Hit Total Coverage
Test: coverage.info Lines: 32 66 48.5 %
Date: 2019-12-15 17:13:15 Functions: 7 9 77.8 %
Legend: Lines: hit not hit

          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_schema.h"
      31             : 
      32             : #include    "snapdatabase/block/block_header.h"
      33             : #include    "snapdatabase/database/table.h"
      34             : 
      35             : 
      36             : // C++ lib
      37             : //
      38             : #include    <iostream>
      39             : 
      40             : 
      41             : // last include
      42             : //
      43             : #include    <snapdev/poison.h>
      44             : 
      45             : 
      46             : 
      47             : namespace snapdatabase
      48             : {
      49             : 
      50             : 
      51             : 
      52             : namespace
      53             : {
      54             : 
      55             : 
      56             : 
      57             : // 'SCHM'
      58             : constexpr struct_description_t g_description[] =
      59             : {
      60             :     define_description(
      61             :           FieldName("header")
      62             :         , FieldType(struct_type_t::STRUCT_TYPE_STRUCTURE)
      63             :         , FieldSubDescription(detail::g_block_header)
      64             :     ),
      65             :     define_description(
      66             :           FieldName("size")
      67             :         , FieldType(struct_type_t::STRUCT_TYPE_UINT32)
      68             :     ),
      69             :     define_description(
      70             :           FieldName("next_schema_block")
      71             :         , FieldType(struct_type_t::STRUCT_TYPE_REFERENCE)
      72             :     ),
      73             :     end_descriptions()
      74             : };
      75             : 
      76             : 
      77             : constexpr descriptions_by_version_t const g_descriptions_by_version[] =
      78             : {
      79             :     define_description_by_version(
      80             :         DescriptionVersion(0, 1),
      81             :         DescriptionDescription(g_description)
      82             :     ),
      83             :     end_descriptions_by_version()
      84             : };
      85             : 
      86             : 
      87             : 
      88             : }
      89             : // no name namespace
      90             : 
      91             : 
      92             : 
      93           1 : block_schema::block_schema(dbfile::pointer_t f, reference_t offset)
      94           1 :     : block(g_descriptions_by_version, f, offset)
      95             : {
      96           1 : }
      97             : 
      98             : 
      99           0 : std::uint32_t block_schema::get_size()
     100             : {
     101           0 :     return static_cast<uint32_t>(f_structure->get_uinteger("size"));
     102             : }
     103             : 
     104             : 
     105           1 : void block_schema::set_size(std::uint32_t size)
     106             : {
     107           1 :     f_structure->set_uinteger("size", size);
     108           1 : }
     109             : 
     110             : 
     111           1 : reference_t block_schema::get_next_schema_block()
     112             : {
     113           1 :     return static_cast<reference_t>(f_structure->get_uinteger("next_schema_block"));
     114             : }
     115             : 
     116             : 
     117           1 : void block_schema::set_next_schema_block(reference_t offset)
     118             : {
     119           1 :     f_structure->set_uinteger("next_schema_block", offset);
     120           1 : }
     121             : 
     122             : 
     123           0 : virtual_buffer::pointer_t block_schema::get_schema() const
     124             : {
     125           0 :     virtual_buffer::pointer_t result(std::make_shared<virtual_buffer>());
     126             : 
     127           0 :     reference_t const offset(f_structure->get_size());
     128           0 :     block_schema::pointer_t s(std::static_pointer_cast<block_schema>(const_cast<block_schema *>(this)->shared_from_this()));
     129             :     for(;;)
     130             :     {
     131           0 :         block::pointer_t block_ptr(s);
     132           0 :         result->add_buffer(block_ptr, offset, s->get_size());
     133           0 :         reference_t next(s->get_next_schema_block());
     134           0 :         if(next == 0)
     135             :         {
     136           0 :             return result;
     137             :         }
     138             : 
     139           0 :         s = std::static_pointer_cast<block_schema>(get_table()->get_block(next));
     140           0 :         if(s == nullptr)
     141             :         {
     142           0 :             throw snapdatabase_logic_error("block_schema::get_schema() failed reading the list of blocks (bad pointer).");
     143             :         }
     144           0 :     }
     145             : }
     146             : 
     147             : 
     148           1 : void block_schema::set_schema(virtual_buffer::pointer_t schema)
     149             : {
     150           1 :     reference_t const offset(f_structure->get_size());
     151             : #ifdef _DEBUG
     152           1 :     if(offset == 0)
     153             :     {
     154           0 :         throw snapdatabase_logic_error("the structure of the block_schema block cannot be dynamic.");
     155             :     }
     156             : #endif
     157           1 :     std::uint32_t const size_per_page(get_table()->get_page_size() - offset);
     158             : 
     159           1 :     std::uint32_t remaining_size(schema->size());
     160           1 :     block_schema * s(this);
     161           1 :     for(std::uint32_t pos(0);;)
     162             :     {
     163           1 :         data_t d(s->data());
     164           1 :         std::uint32_t const size(std::min(size_per_page, remaining_size));
     165           1 :         schema->pread(d + offset, size, pos);
     166           1 :         s->set_size(size);
     167             : 
     168           1 :         reference_t next(s->get_next_schema_block());
     169             : 
     170           1 :         pos += size;
     171           1 :         remaining_size -= size;
     172           1 :         if(remaining_size == 0)
     173             :         {
     174           1 :             s->set_next_schema_block(NULL_FILE_ADDR);
     175           1 :             s->sync(false);
     176             : 
     177             :             // free any "next" block (happens when a schema shrinks)
     178             :             //
     179           1 :             while(next != NULL_FILE_ADDR)
     180             :             {
     181           0 :                 block_schema::pointer_t next_schema(std::static_pointer_cast<block_schema>(get_table()->get_block(next)));
     182           0 :                 if(next_schema == nullptr)
     183             :                 {
     184             :                     throw snapdatabase_logic_error(
     185             :                               "reading of the next schema block at "
     186           0 :                             + std::to_string(next)
     187           0 :                             + " failed.");
     188             :                 }
     189           0 :                 next = next_schema->get_next_schema_block();
     190           0 :                 get_table()->free_block(next_schema, false);
     191             :             }
     192             : 
     193           1 :             break;
     194             :         }
     195             : 
     196           0 :         if(next == NULL_FILE_ADDR)
     197             :         {
     198             :             // create a new block and link it
     199             :             //
     200           0 :             block_schema::pointer_t new_block(std::static_pointer_cast<block_schema>(get_table()->allocate_new_block(dbtype_t::BLOCK_TYPE_SCHEMA)));
     201           0 :             s->set_next_schema_block(new_block->get_offset());
     202           0 :             s->sync(false);
     203           0 :             s = new_block.get();
     204             :         }
     205             :         else
     206             :         {
     207           0 :             block_schema::pointer_t next_schema(std::static_pointer_cast<block_schema>(get_table()->get_block(next)));
     208           0 :             if(next_schema == nullptr)
     209             :             {
     210             :                 throw snapdatabase_logic_error(
     211             :                           "reading of the next schema block at "
     212           0 :                         + std::to_string(next)
     213           0 :                         + " failed.");
     214             :             }
     215             : 
     216           0 :             s->sync(false);
     217           0 :             s = next_schema.get();
     218             :         }
     219           0 :     }
     220           1 : }
     221             : 
     222             : 
     223           6 : } // namespace snapdatabase
     224             : // vim: ts=4 sw=4 et

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