Details

    • Type: Task
    • Status: Closed (View Workflow)
    • Priority: Major
    • Resolution: Fixed
    • Fix Version/s: 10.5.0
    • Component/s: GIS
    • Labels:
      None

      Description

      Data type plugins should be able to provide their own sets of built-in functions.

      Let's add a new class Function_collection, as follows:

      class Function_collection
      {
      public:
        virtual ~Function_collection() {}
        virtual bool init()= 0;
        virtual void cleanup()= 0;
        virtual Create_func *find_native_function_builder(THD *thd,
                                                          const LEX_CSTRING &name)
                                                          const= 0;
      };
      

      and, as a prove of the conceipt, move all GIS functions into a new class Function_collection_geometry.

      • The method init() will do the collection initialization, e.g. create a hash to lookup Create_func builders by function names.
      • The method cleanup will free all memory allocated by init(), e.g. free the lookup hash.
      • The method find_native_function_builder will lookup a function by name and return its Create_func builder (or NULL if the function is not found).

      This task will also do the following:

      • Move all GIS function Create_func_xxx classes from item_create_cc to item_geofunc.cc
      • Move definitions of Create_func_arg0, Create_func_arg1, Create_func_arg2, Create_func_arg3 from item_create.cc to item_create.h, so function collection plugins can reuse these classes.
      • Remove this code from the bison grammar:

        -        | geometry_function
        -          {
        -#ifdef HAVE_SPATIAL
        -            $$= $1;
        -            /* $1 may be NULL, GEOM_NEW not tested for out of memory */
        -            if (unlikely($$ == NULL))
        -              MYSQL_YYABORT;
        -#else
        -            my_yyabort_error((ER_FEATURE_DISABLED, MYF(0), sym_group_geom.name,
        -                              sym_group_geom.needed_define));
        -#endif
        -          }
        -        ;
        -
        -geometry_function:
        -          CONTAINS_SYM '(' expr ',' expr ')'
        -          {
        -            $$= GEOM_NEW(thd,
        -                         Item_func_spatial_precise_rel(thd, $3, $5,
        -                                                 Item_func::SP_CONTAINS_FUNC));
        -          }
        -        | WITHIN '(' expr ',' expr ')'
        -          {
        -            $$= GEOM_NEW(thd, Item_func_spatial_precise_rel(thd, $3, $5,
        -                                                    Item_func::SP_WITHIN_FUNC));
        -          }
        
        

        and add something like this into the function_call_generic rule:

                | CONTAINS_SYM '(' opt_expr_list ')'
                  {
                    if (!($$= Lex->make_item_func_call_native_or_parse_error(thd,
                                                                             $1, $3)))
                      MYSQL_YYABORT;
                  }
                | WITHIN '(' opt_expr_list ')'
                  {
                    if (!($$= Lex->make_item_func_call_native_or_parse_error(thd,
                                                                             $1, $3)))
                      MYSQL_YYABORT;
                  }
        

      • Add a global instance of Function_collection_geometry

      Later, in a separate MDEV, we'll add a new plugin type, MYSQL_FUNCTION_COLLECTION_PLUGIN.

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              • Assignee:
                bar Alexander Barkov
                Reporter:
                bar Alexander Barkov
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                Dates

                • Created:
                  Updated:
                  Resolved: