check hashes of files instead

Author: kkiesling

openmc_plotter/main_window.py

@@ -1068,13 +1068,10 @@ def restoreModelSettings(self):
                 model = pickle.load(file)
 
                 # check if loaded cell/mat ids hash match the pkl file:
-                current_mat_hash = hashlib.md5(
-                    pickle.dumps(self.model.mat_ids)).hexdigest()
-                current_cell_hash = hashlib.md5(
-                    pickle.dumps(self.model.cell_ids)).hexdigest()
-
-                if (current_mat_hash != model.mat_ids_hash) or \
-                    (current_cell_hash != model.cell_ids_hash):
+                current_mat_xml_hash = self.hash_file('materials.xml')
+                current_geom_xml_hash = self.hash_file('geometry.xml')
+                if (current_mat_xml_hash != model.mat_xml_hash) or \
+                    (current_geom_xml_hash != model.geom_xml_hash):
                     # hashes do not match so ignore plot_settings.pkl file
                     pkl_settings_warn = "WARNING: Model has changed since " +\
                                         "storing plot settings. Ignoring " +\
@@ -1202,11 +1199,9 @@ def saveSettings(self):
         if len(self.model.subsequentViews) > 10:
             self.model.subsequentViews = self.model.subsequentViews[-10:]
 
-        # get hashes for cell/mat ids at close
-        self.model.cell_ids_hash = hashlib.md5(
-            pickle.dumps(self.model.cell_ids)).hexdigest()
-        self.model.mat_ids_hash = hashlib.md5(
-            pickle.dumps(self.model.mat_ids)).hexdigest()
+        # get hashes for geometry.xml and material.xml at close
+        self.model.mat_xml_hash = self.hash_file('materials.xml')
+        self.model.geom_xml_hash = self.hash_file('geometry.xml')
 
         with open('plot_settings.pkl', 'wb') as file:
             if self.model.statepoint:
@@ -1216,3 +1211,15 @@ def saveSettings(self):
     def exportTallyData(self):
         # show export tool dialog
         self.showExportDialog()
+
+    @staticmethod
+    def hash_file(filename):
+        # return the md5 hash of a file
+        h = hashlib.md5()
+        with open(filename,'rb') as file:
+            chunk = 0
+            while chunk != b'':
+                # read 1024 bytes at a time
+                chunk = file.read(1024)
+                h.update(chunk)
+        return h.hexdigest()