1338 Enhance save_final in CheckpointSaver handler

monai/handlers/checkpoint_saver.py

@@ -188,6 +188,13 @@ def attach(self, engine: Engine) -> None:
             else:
                 engine.add_event_handler(Events.ITERATION_COMPLETED(every=self.save_interval), self.interval_completed)
 
+    def _delete_previous_final_ckpt(self):
+        saved = self._final_checkpoint._saved
+        if len(saved) > 0:
+            item = saved.pop(0)
+            self._final_checkpoint.save_handler.remove(item.filename)
+            self.logger.info(f"Deleted previous saved final checkpoint: {item.filename}")
+
     def completed(self, engine: Engine) -> None:
         """Callback for train or validation/evaluation completed Event.
         Save final checkpoint if configure save_final is True.
@@ -196,6 +203,8 @@ def completed(self, engine: Engine) -> None:
             engine: Ignite Engine, it can be a trainer, validator or evaluator.
         """
         assert callable(self._final_checkpoint), "Error: _final_checkpoint function not specified."
+        # delete previous saved final checkpoint if existing
+        self._delete_previous_final_ckpt()
         self._final_checkpoint(engine)
         assert self.logger is not None
         assert hasattr(self.logger, "info"), "Error, provided logger has not info attribute."
@@ -211,6 +220,8 @@ def exception_raised(self, engine: Engine, e: Exception) -> None:
             e: the exception caught in Ignite during engine.run().
         """
         assert callable(self._final_checkpoint), "Error: _final_checkpoint function not specified."
+        # delete previous saved final checkpoint if existing
+        self._delete_previous_final_ckpt()
         self._final_checkpoint(engine)
         assert self.logger is not None
         assert hasattr(self.logger, "info"), "Error, provided logger has not info attribute."

tests/test_handler_checkpoint_saver.py

@@ -117,6 +117,7 @@ def _train_func(engine, batch):
                 n_saved,
             )
             handler.attach(engine)
+            engine.run(data, max_epochs=2)
             engine.run(data, max_epochs=5)
             for filename in filenames:
                 self.assertTrue(os.path.exists(os.path.join(tempdir, filename)))