netCDF: Partial implementation of get_file_fields

Not done yet, but I need to leave soon...

src/framework/MOM_io_file.F90

@@ -28,6 +28,7 @@ module MOM_io_file
 use MOM_netcdf, only : write_netcdf_axis
 use MOM_netcdf, only : write_netcdf_attribute
 use MOM_netcdf, only : get_netcdf_size
+use MOM_netcdf, only : get_netcdf_fields
 
 implicit none ; private
 
@@ -1501,12 +1502,25 @@ subroutine get_file_info_nc(handle, ndim, nvar, ntime)
 end subroutine get_file_info_nc
 
 
-!> Return the field metadata associated with a MOM framework file
+!> Return the field metadata associated with a MOM netCDF file
 subroutine get_file_fields_nc(handle, fields)
   class(MOM_netcdf_file), intent(inout) :: handle
   type(MOM_field), intent(inout) :: fields(:)
 
-  ! TODO
+  type(netcdf_field), allocatable :: fields_nc(:)
+  integer :: i
+  character(len=64) :: label
+
+  allocate(fields_nc(size(fields)))
+  call get_netcdf_fields(handle%handle_nc, fields_nc)
+
+  do i = 1, size(fields)
+    ! TODO
+    !call get_field_atts(fields_nc(i), name=label)
+    !call handle%fields%append(fields_nc(i), trim(label))
+    !fields(i)%label = trim(label)
+  enddo
+
   !call get_file_fields(handle%handle_nc, fields)
 end subroutine get_file_fields_nc
 

src/framework/MOM_netcdf.F90

@@ -16,6 +16,7 @@ module MOM_netcdf
 use netcdf, only : nf90_strerror, NF90_NOERR
 use netcdf, only : NF90_GLOBAL
 use netcdf, only : nf90_inquire, nf90_inquire_dimension
+use netcdf, only : nf90_inq_dimids, nf90_inq_varids
 
 use MOM_error_handler, only : MOM_error, FATAL
 use MOM_io_infra, only : READONLY_FILE, WRITEONLY_FILE
@@ -35,6 +36,7 @@ module MOM_netcdf
 public :: write_netcdf_axis
 public :: write_netcdf_attribute
 public :: get_netcdf_size
+public :: get_netcdf_fields
 
 ! TODO: How much of these types can be made private?
 
@@ -532,6 +534,51 @@ subroutine get_netcdf_size(handle, ndims, nvars, nsteps)
 end subroutine get_netcdf_size
 
 
+! TODO: Can this be a function?
+subroutine get_netcdf_fields(handle, fields)
+  type(netcdf_file_type), intent(in) :: handle
+  type(netcdf_field), intent(inout), allocatable :: fields(:)
+
+  integer :: ndims
+    ! Number of netCDF dimensions
+  integer :: nvars
+    ! Number of netCDF variables (including axes)
+  integer :: nfields
+    ! Number of fields (i.e. non-axis netCDF variables)
+  integer :: rc
+    ! netCDF return code
+  integer, allocatable :: dim_ids(:)
+    ! netCDF dimension IDs
+  integer, allocatable :: field_ids(:)
+    ! netCDF field variable IDs
+  integer :: grp_ndims, grp_nvars
+    ! Group-based counts for nf90_inq_* (unused)
+  integer :: i
+
+  integer, save :: no_parent_groups = 0
+    ! Flag indicating exclusion of parent groups in netCDF file
+    ! NOTE: This must be passed as a variable, and cannot be declared as a
+    !   parameter, so must be declared as a variable.
+
+  rc = nf90_inquire(handle%ncid, nDimensions=ndims, nVariables=nvars)
+  call check_netcdf_call(rc, 'get_netcdf_fields', &
+      'File "' // handle%filename // '"')
+
+  ! Gather the axes, to be removed from the field list
+  rc = nf90_inq_dimids(handle%ncid, grp_ndims, dim_ids, no_parent_groups)
+  call check_netcdf_call(rc, 'get_netcdf_fields', &
+      'File "' // handle%filename // '"')
+
+  allocate(field_ids(nvars))
+  rc = nf90_inq_varids(handle%ncid, grp_nvars, field_ids)
+  call check_netcdf_call(rc, 'get_netcdf_fields', &
+      'File "' // handle%filename // '"')
+
+  nfields = nvars - ndims
+  allocate(fields(nfields))
+end subroutine get_netcdf_fields
+
+
 !> Check netCDF function return codes, report the error log, and abort the run.
 subroutine check_netcdf_call(ncerr, header, message)
   integer, intent(in) :: ncerr