Check CICE4 restart file dates

payu/models/access.py

@@ -16,6 +16,7 @@
 import re
 import shutil
 import sys
+import struct
 
 # Extensions
 import f90nml
@@ -218,6 +219,12 @@ def setup(self):
                 f90nml.write(cpl_nml, nml_work_path + '~')
                 shutil.move(nml_work_path + '~', nml_work_path)
 
+            if model.model_type == 'cice':
+                # Set up and check the cice restart files.
+                cice4_make_restart_pointer(model,
+                                           run_start_date,
+                                           previous_runtime)
+
         # Now change the oasis runtime. This needs to be done after the others.
         for model in self.expt.models:
             if model.model_type == 'oasis':
@@ -333,3 +340,65 @@ def set_model_output_paths(self):
 
     def collate(self):
         pass
+
+
+def cice4_make_restart_pointer(cice_model, run_start_date, previous_runtime):
+    """
+    Generate restart pointer file 'ice.restart_file' specifying
+    the correct 'iced.YYYYMMDD' restart file, based on the run
+    start date.
+    Additionally check that the `iced.YYYYMNDD` restart file's header
+    has the correct previous runtime.
+    """
+    # Expected iced restart file name based on start date
+    run_start_date_int = cal.date_to_int(run_start_date)
+    iced_restart_file = f"iced.{run_start_date_int:08d}"
+
+    if iced_restart_file not in cice_model.get_prior_restart_files():
+        msg = (f"Expected restart file {iced_restart_file} based on "
+               f"run start date {run_start_date_int} "
+               f"not found in {cice_model.prior_restart_path}.")
+        raise FileNotFoundError(msg)
+
+    res_ptr_path = os.path.join(cice_model.work_init_path,
+                                'ice.restart_file')
+    if os.path.islink(res_ptr_path):
+        # If we've linked in a previous pointer it should be deleted
+        os.remove(res_ptr_path)
+
+    iced_path = os.path.join(cice_model.prior_restart_path,
+                             iced_restart_file)
+
+    # Check that the prior run time in the iced restart header matches
+    # the previous runtime calculated from the calendar file.
+    cice4_check_date_consistency(cice_model, iced_path, previous_runtime)
+
+    with open(res_ptr_path, 'w') as res_ptr:
+        res_dir = cice_model.get_ptr_restart_dir()
+        res_ptr.write(os.path.join(res_dir, iced_restart_file))
+
+
+def cice4_check_date_consistency(cice_model, iced_path, previous_runtime):
+    """
+    Check that the previous runtime in iced restart file header
+    matches the runtime calculated from the calendar restart file.
+    """
+    _, _, cice_iced_runtime, _ = read_binary_iced_header(iced_path)
+    if previous_runtime != cice_iced_runtime:
+        msg = (f"Previous runtime from calendar file "
+               f"{cice_model.start_date_nml_name}: {previous_runtime} "
+               "does not match previous runtime in restart"
+               f"file {iced_path}: {cice_iced_runtime}."
+               )
+        raise RuntimeError(msg)
+
+
+def read_binary_iced_header(iced_path):
+    """
+    Read header information from a CICE4 binary restart file.
+    """
+    with open(iced_path, 'rb') as iced_file:
+        header = iced_file.read(24)
+        bint, istep0, time, time_forc = struct.unpack('>iidd', header)
+
+    return (bint, istep0, time, time_forc)

payu/models/cice.py

@@ -162,29 +162,10 @@ def setup(self):
             self.ice_in.patch(history_nml)
 
         setup_nml = self.ice_in['setup_nml']
+        self._calc_runtime()
 
         if self.prior_restart_path:
-            # Generate ice.restart_file
-            # TODO: better check of restart filename
-            iced_restart_file = None
-            iced_restart_files = [f for f in self.get_prior_restart_files()
-                                  if f.startswith('iced.')]
-
-            if len(iced_restart_files) > 0:
-                iced_restart_file = sorted(iced_restart_files)[-1]
-
-            if iced_restart_file is None:
-                raise FileNotFoundError(
-                    f'No iced restart file found in {self.prior_restart_path}')
-
-            res_ptr_path = os.path.join(self.work_init_path,
-                                        'ice.restart_file')
-            if os.path.islink(res_ptr_path):
-                # If we've linked in a previous pointer it should be deleted
-                os.remove(res_ptr_path)
-            with open(res_ptr_path, 'w') as res_ptr:
-                res_dir = self.get_ptr_restart_dir()
-                print(os.path.join(res_dir, iced_restart_file), file=res_ptr)
+            self.make_restart_ptr()
 
             # Update input namelist
             setup_nml['runtype'] = 'continue'
@@ -198,8 +179,6 @@ def setup(self):
             if setup_nml['restart']:
                 self.link_restart(setup_nml['pointer_file'])
 
-        self._calc_runtime()
-
         # Write any changes to the work directory copy of the cice
         # namelist
         nml_path = os.path.join(self.work_path, self.ice_nml_fname)
@@ -351,3 +330,10 @@ def link_restart(self, fpath):
             )
 
         make_symlink(input_path, input_work_path)
+
+    def make_restart_ptr(self):
+        """
+        CICE4 restart pointers are created by the access driver, where
+        the correct run start dates are available.
+        """
+        pass

payu/models/cice5.py

@@ -78,3 +78,28 @@ def _calc_runtime(self):
         the timing information in the cice_in.nml namelist.
         """
         pass
+
+    def make_restart_ptr(self):
+        """
+        Generate restart pointer which points to the latest iced.YYYYMMDD
+        restart file.
+        """
+        iced_restart_file = None
+        iced_restart_files = [f for f in self.get_prior_restart_files()
+                              if f.startswith('iced.')]
+
+        if len(iced_restart_files) > 0:
+            iced_restart_file = sorted(iced_restart_files)[-1]
+
+        if iced_restart_file is None:
+            raise FileNotFoundError(
+                f'No iced restart file found in {self.prior_restart_path}')
+
+        res_ptr_path = os.path.join(self.work_init_path,
+                                    'ice.restart_file')
+        if os.path.islink(res_ptr_path):
+            # If we've linked in a previous pointer it should be deleted
+            os.remove(res_ptr_path)
+        with open(res_ptr_path, 'w') as res_ptr:
+            res_dir = self.get_ptr_restart_dir()
+            res_ptr.write(os.path.join(res_dir, iced_restart_file))