Reworked Configuration Namelist Access API

CONTRIBUTORS.md

@@ -4,8 +4,9 @@
 | andrewcoughtrie | Andrew Coughtrie | Met Office  | 2025.12.12 |
 | james-bruten-mo | James Bruten     | Met Office  | 2025-12-09 |
 | jennyhickson    | Jenny Hickson    | Met Office  | 2025-12-10 |
-| mo-marqh        | Mark Hedley      | Met Office  | 2025-12-11 |
 | mike-hobson     | Mike Hobson      | Met Office  | 2025-12-17 |
+| mo-marqh        | Mark Hedley      | Met Office  | 2025-12-11 |
+| mo-rickywong    | Ricky Wong       | Met Office  | 2025-12-11 |
 | MatthewHambley  | Matthew Hambley  | Met Office  | 2025-12-15 |
 | yaswant         | Yaswant Pradhan  | Met Office  | 2025-12-16 |
 | harry-shepherd  | Harry Shepherd   | Met Office  | 2026-01-08 |

applications/coupled/source/coupled.f90

@@ -43,6 +43,7 @@ program coupled
   call modeldb%values%initialise( 'values', 5 )
 
   call modeldb%configuration%initialise( program_name, table_len=10 )
+  call modeldb%config%initialise( program_name )
 
   write(log_scratch_space,'(A)')                          &
       'Application built with '// trim(precision_real) // &
@@ -53,8 +54,12 @@ program coupled
 
   call modeldb%values%add_key_value('cpl_name', cpl_component_name)
   call init_comm( "coupled", modeldb )
-  call init_config( filename, coupled_required_namelists, &
-                    modeldb%configuration )
+
+  call init_config( filename,                            &
+                    coupled_required_namelists,          &
+                    configuration=modeldb%configuration, &
+                    config=modeldb%config )
+
   call init_logger( modeldb%mpi%get_comm(), &
                     program_name//"_"//cpl_component_name )
   call init_collections()

applications/coupled/source/driver/coupled_driver_mod.f90

@@ -32,7 +32,7 @@ module coupled_driver_mod
                                          LOG_LEVEL_INFO
   use mesh_mod,                   only : mesh_type
   use mesh_collection_mod,        only : mesh_collection
-  use namelist_mod,               only : namelist_type
+
   use sci_checksum_alg_mod,       only : checksum_alg
 
   implicit none
@@ -69,10 +69,6 @@ subroutine initialise( program_name, modeldb, calendar )
     class(extrusion_type),        allocatable :: extrusion
     type(uniform_extrusion_type), allocatable :: extrusion_2d
 
-    type(namelist_type), pointer :: base_mesh_nml
-    type(namelist_type), pointer :: planet_nml
-    type(namelist_type), pointer :: extrusion_nml
-
     character(str_def) :: prime_mesh_name
 
     integer(i_def) :: stencil_depth
@@ -89,18 +85,12 @@ subroutine initialise( program_name, modeldb, calendar )
 
 
     ! Extract namelist variables
-    base_mesh_nml => modeldb%configuration%get_namelist('base_mesh')
-    planet_nml    => modeldb%configuration%get_namelist('planet')
-    extrusion_nml => modeldb%configuration%get_namelist('extrusion')
-    call base_mesh_nml%get_value( 'prime_mesh_name', prime_mesh_name )
-    call base_mesh_nml%get_value( 'geometry', geometry )
-    call extrusion_nml%get_value( 'method', method )
-    call extrusion_nml%get_value( 'domain_height', domain_height )
-    call extrusion_nml%get_value( 'number_of_layers', number_of_layers )
-    call planet_nml%get_value( 'scaled_radius', scaled_radius )
-    base_mesh_nml => null()
-    planet_nml    => null()
-    extrusion_nml => null()
+    prime_mesh_name  = modeldb%config%base_mesh%prime_mesh_name()
+    geometry         = modeldb%config%base_mesh%geometry()
+    method           = modeldb%config%extrusion%method()
+    domain_height    = modeldb%config%extrusion%domain_height()
+    number_of_layers = modeldb%config%extrusion%number_of_layers()
+    scaled_radius    = modeldb%config%planet%scaled_radius()
 
     ! Initialise mesh
     ! Determine the required meshes
@@ -118,7 +108,7 @@ subroutine initialise( program_name, modeldb, calendar )
                       LOG_LEVEL_ERROR)
     end select
     allocate( extrusion, source=create_extrusion( method,           &
-                                                  domain_height,       &
+                                                  domain_height,    &
                                                   domain_bottom,    &
                                                   number_of_layers, &
                                                   PRIME_EXTRUSION ) )

applications/coupled/source/driver/init_coupled_mod.X90

@@ -21,8 +21,8 @@ module init_coupled_mod
   use field_collection_mod,           only : field_collection_type
   use field_mod,                      only : field_type
   use field_parent_mod,               only : write_interface
-  use finite_element_config_mod,      only : element_order_h, element_order_v
   use function_space_collection_mod,  only : function_space_collection
+  use function_space_mod,             only : function_space_type
   use fs_continuity_mod,              only : W3
   use log_mod,                        only : log_event,      &
                                              LOG_LEVEL_INFO, &
@@ -40,11 +40,12 @@ module init_coupled_mod
   !> @param[in,out] chi The co-ordinate field
   !> @param[in,out] panel_id 2d field giving the id for cubed sphere panels
   !> @param[in,out] modeldb The structure that holds model state
-  subroutine init_coupled( mesh, chi, panel_id, modeldb)
+  subroutine init_coupled(mesh, chi, panel_id, modeldb)
 
     implicit none
 
     type(mesh_type), intent(in), pointer     :: mesh
+
     ! Coordinate field
     type( field_type ), intent(inout)        :: chi(:)
     type( field_type ), intent(inout)        :: panel_id
@@ -74,19 +75,23 @@ module init_coupled_mod
 
     procedure(write_interface), pointer :: tmp_ptr
 
+    integer(i_def) :: order_h, order_v
+    type(function_space_type), pointer :: fs
+
     call log_event( 'coupled: Initialising app ...', LOG_LEVEL_INFO )
 
     ! Get the name of the coupling component
     call modeldb%values%get_value("cpl_name", cpl_component_name)
 
+    order_h = modeldb%config%finite_element%element_order_h()
+    order_v = modeldb%config%finite_element%element_order_v()
+
+    fs => function_space_collection%get_fs(mesh, order_h, order_v, W3)
+
     ! Create prognostic fields
     ! Creates a field in the W3 function space (fully discontinuous field)
-    call field_1%initialise( vector_space = &
-                    function_space_collection%get_fs(mesh, element_order_h, element_order_v, W3), &
-                             name="field_1")
-    call field_2%initialise( vector_space = &
-                    function_space_collection%get_fs(mesh, element_order_h, element_order_v, W3), &
-                             name="field_2")
+    call field_1%initialise(fs, name="field_1")
+    call field_2%initialise(fs, name="field_2")
 
     ! Add field to modeldb
     depository => modeldb%fields%get_field_collection("depository")

applications/io_demo/source/algorithm/io_demo_alg_mod.x90

@@ -6,16 +6,18 @@
 
 !>@brief Module containing io_demo_alg
 module io_demo_alg_mod
+
   use constants_mod,                       only: i_def,r_def
+  use driver_modeldb_mod,                  only: modeldb_type
   use log_mod,                             only: log_event,         &
                                                  LOG_LEVEL_INFO,    &
                                                  LOG_LEVEL_TRACE
   use mesh_mod,                            only: mesh_type
+
   use field_mod,                           only: field_type
-  use finite_element_config_mod,           only: element_order_h,  &
-                                                 element_order_v
-  use fs_continuity_mod,                   only: Wtheta, W2
+  use fs_continuity_mod,                   only: Wtheta
   use function_space_collection_mod,       only: function_space_collection
+  use function_space_mod,                  only: function_space_type
   use operator_mod,                        only: operator_type
   use matrix_vector_kernel_mod,            only: matrix_vector_kernel_type
   use io_demo_constants_mod,               only: get_dx_at_w2
@@ -31,11 +33,14 @@ module io_demo_alg_mod
 contains
 
   !> @details Calculates the diffusion increment for a field, and adds it to said field.
+  !> @param[in]    modeldb   Application state object
   !> @param[inout] field_in  Input Wtheta field
-  subroutine io_demo_alg( field_in )
+  subroutine io_demo_alg( modeldb, field_in )
 
     implicit none
 
+    type(modeldb_type), intent(in) :: modeldb
+
     ! Prognostic fields
     type( field_type ), intent( inout ) :: field_in
 
@@ -44,20 +49,27 @@ contains
     type( field_type )                  :: visc
 
     real(r_def), parameter              :: visc_val = 100000.0_r_def
-    type(mesh_type), pointer            :: mesh => null()
     integer(kind=i_def), parameter      :: stencil_depth = 1_i_def
-    type( field_type ), pointer         :: dx_at_w2 => null()
 
+    type(mesh_type),           pointer :: mesh
+    type(field_type),          pointer :: dx_at_w2
+    type(function_space_type), pointer :: fs
+
+    integer(i_def) :: order_h, order_v
 
     call log_event( "io_demo: Running algorithm", LOG_LEVEL_TRACE )
-    mesh => field_in%get_mesh()
+
+    order_h = modeldb%config%finite_element%element_order_h()
+    order_v = modeldb%config%finite_element%element_order_v()
+
+    mesh     => field_in%get_mesh()
     dx_at_w2 => get_dx_at_w2(mesh)
-    call dfield_in%initialise( &
-      function_space_collection%get_fs( mesh, element_order_h, &
-                                        element_order_v, Wtheta))
-    call visc%initialise( &
-      function_space_collection%get_fs( mesh, element_order_h, &
-                                        element_order_v, Wtheta))
+
+    fs => function_space_collection%get_fs(mesh, order_h, order_v, Wtheta)
+
+    call dfield_in%initialise(fs)
+    call visc%initialise(fs)
+
     call invoke( name = "compute_diffusion", &
                  setval_c(visc, visc_val), &
                  setval_c(dfield_in, 0.0_r_def), &

applications/io_demo/source/algorithm/io_demo_constants_mod.x90

@@ -15,30 +15,30 @@
 module io_demo_constants_mod
 
   ! Infrastructure
-  use constants_mod,                      only: i_def, r_def, &
+  use constants_mod,                      only: i_def, r_def, l_def, &
                                                 str_def, str_short
+  use driver_modeldb_mod,                 only: modeldb_type
   use field_collection_mod,               only: field_collection_type
   use field_mod,                          only: field_type
   use fs_continuity_mod,                  only: W2
   use function_space_collection_mod,      only: function_space_collection
   use function_space_mod,                 only: function_space_type
-  use io_config_mod,                      only: subroutine_timers
   use log_mod,                            only: log_event, LOG_LEVEL_TRACE, &
                                                 LOG_LEVEL_ERROR
   use mesh_mod,                           only: mesh_type
   use timer_mod,                          only: timer
 
   ! Kernels
-  use sci_calc_dA_at_w2_kernel_mod,           only: calc_dA_at_w2_kernel_type
-  use sci_calc_detj_at_w2_kernel_mod,         only: calc_detj_at_w2_kernel_type
-  use sci_multiplicity_kernel_mod,            only: multiplicity_kernel_type
+  use sci_calc_dA_at_w2_kernel_mod,   only: calc_dA_at_w2_kernel_type
+  use sci_calc_detj_at_w2_kernel_mod, only: calc_detj_at_w2_kernel_type
+  use sci_multiplicity_kernel_mod,    only: multiplicity_kernel_type
 
   implicit none
 
   private
 
   ! Objects for dx_at_w2 functionality
-  type(field_collection_type)      :: dx_at_w2_collection
+  type(field_collection_type) :: dx_at_w2_collection
 
   private :: add_dx_at_w2
 
@@ -48,19 +48,24 @@ module io_demo_constants_mod
 contains
 
   !> @brief Subroutine to create the finite element constants
+  !> @param[in] modeldb   Application state object
   !> @param[in] mesh      The prime model mesh
   !> @param[in] chi       Coordinate fields
   !> @param[in] panel_id  Panel_id field
-  subroutine create_io_demo_constants(mesh,    &
-                                       chi,     &
-                                       panel_id )
+  subroutine create_io_demo_constants(modeldb, mesh, chi, panel_id)
 
     implicit none
 
     ! Arguments
-    type(mesh_type),    pointer, intent(in) :: mesh
-    type(field_type),    target, intent(in) :: chi(:)
-    type(field_type),    target, intent(in) :: panel_id
+    type(modeldb_type), intent(in) :: modeldb
+
+    type(mesh_type),  pointer, intent(in) :: mesh
+    type(field_type),  target, intent(in) :: chi(:)
+    type(field_type),  target, intent(in) :: panel_id
+
+    logical(l_def) :: subroutine_timers
+
+    subroutine_timers = modeldb%config%io%subroutine_timers()
 
     if ( subroutine_timers ) call timer('io_demo_constants_alg')
     call log_event( "io_demo: creating runtime constants", LOG_LEVEL_TRACE )

applications/io_demo/source/driver/init_io_demo_mod.F90

@@ -12,22 +12,19 @@
 module init_io_demo_mod
 
   use sci_assign_field_random_range_alg_mod,  only: assign_field_random_range
-  use constants_mod,                          only : i_def, r_def
+  use constants_mod,                          only : i_def, r_def, l_def
   use driver_modeldb_mod,                     only : modeldb_type
   use field_collection_mod,                   only : field_collection_type
   use field_mod,                              only : field_type
   use field_parent_mod,                       only : write_interface
-  use finite_element_config_mod,              only : element_order_h, &
-                                                     element_order_v
   use function_space_collection_mod,          only : function_space_collection
+  use function_space_mod,                     only : function_space_type
   use fs_continuity_mod,                      only : Wtheta
   use key_value_mod,                          only : abstract_value_type
   use log_mod,                                only : log_event,       &
                                                      LOG_LEVEL_TRACE, &
                                                      LOG_LEVEL_ERROR
   use mesh_mod,                               only : mesh_type
-  use io_config_mod,                          only : write_diag, &
-                                                     use_xios_io
   use lfric_xios_write_mod,                   only : write_field_generic
   use io_demo_constants_mod,                  only : create_io_demo_constants
   use random_number_generator_mod,            only : random_number_generator_type
@@ -37,20 +34,21 @@ module init_io_demo_mod
   contains
 
   !> @details Initialises everything needed to run the io_demo miniapp
+  !> @param[in,out] modeldb The structure that holds model state
   !> @param[in]     mesh Representation of the mesh the code will run on
   !> @param[in,out] chi The co-ordinate field
   !> @param[in,out] panel_id 2d field giving the id for cubed sphere panels
-  !> @param[in,out] modeldb The structure that holds model state
-  subroutine init_io_demo( mesh, chi, panel_id, modeldb)
+  subroutine init_io_demo(modeldb, mesh, chi, panel_id)
 
     implicit none
 
-    type(mesh_type), intent(in), pointer        :: mesh
+    type(modeldb_type), intent(inout)       :: modeldb
+    type(mesh_type),    intent(in), pointer :: mesh
 
     ! Coordinate field
-    type(field_type), intent(inout)             :: chi(:)
-    type(field_type), intent(inout)             :: panel_id
-    type(modeldb_type), intent(inout)           :: modeldb
+    type(field_type), intent(inout) :: chi(:)
+    type(field_type), intent(inout) :: panel_id
+
     class(abstract_value_type), pointer         :: abstract_value
     type(random_number_generator_type), pointer :: rng
     type(field_type)                            :: diffusion_field
@@ -59,8 +57,20 @@ subroutine init_io_demo( mesh, chi, panel_id, modeldb)
     real(kind=r_def), parameter                 :: min_val = 280.0_r_def
     real(kind=r_def), parameter                 :: max_val = 330.0_r_def
 
+    type(function_space_type), pointer :: fs
+
+    integer(i_def) :: order_h, order_v
+    logical(l_def) :: write_diag
+    logical(l_def) :: use_xios_io
+
     call log_event( 'io_demo: Initialising miniapp ...', LOG_LEVEL_TRACE )
 
+    order_h = modeldb%config%finite_element%element_order_h()
+    order_v = modeldb%config%finite_element%element_order_v()
+
+    write_diag  = modeldb%config%io%write_diag()
+    use_xios_io = modeldb%config%io%use_xios_io()
+
     ! seed the random number generator
     call modeldb%values%get_value("rng", abstract_value)
     select type(abstract_value)
@@ -76,10 +86,8 @@ subroutine init_io_demo( mesh, chi, panel_id, modeldb)
 
     ! Create prognostic fields
     ! Creates a field in the Wtheta function space
-    call diffusion_field%initialise( vector_space = &
-                    function_space_collection%get_fs(mesh, element_order_h, &
-                                                     element_order_v, Wtheta), &
-                             name="diffusion_field")
+    fs => function_space_collection%get_fs(mesh, order_h, order_v, Wtheta)
+    call diffusion_field%initialise(fs, name="diffusion_field")
 
     ! Set up field with an IO behaviour (XIOS only at present)
     if (write_diag .and. use_xios_io) then
@@ -98,7 +106,7 @@ subroutine init_io_demo( mesh, chi, panel_id, modeldb)
     ! Create io_demo runtime constants. This creates various things
     ! needed by the fem algorithms such as mass matrix operators, mass
     ! matrix diagonal fields and the geopotential field
-    call create_io_demo_constants(mesh, chi, panel_id)
+    call create_io_demo_constants(modeldb, mesh, chi, panel_id)
 
     call log_event( 'io_demo: Miniapp initialised', LOG_LEVEL_TRACE )