save name of last model to disk whenever model changes

- this allows invokeai to restore the last used model on startup, even
  after a crash or keyboard interrupt.

ldm/generate.py

@@ -22,6 +22,7 @@ import transformers
 from diffusers.pipeline_utils import DiffusionPipeline
 from diffusers.utils.import_utils import is_xformers_available
 from omegaconf import OmegaConf
+from pathlib import Path
 from PIL import Image, ImageOps
 from pytorch_lightning import logging, seed_everything
 
@@ -991,8 +992,17 @@ class Generate:
 
         self.model_name = model_name
         self._set_sampler()  # requires self.model_name to be set first
+        self._save_last_used_model(model_name)
         return self.model
 
+    def _save_last_used_model(self,model_name:str):
+        """
+        Save name of the last model used.
+        """
+        model_file_path = Path(Globals.root,'.last_model')
+        with open(model_file_path,'w') as f:
+            f.write(model_name)
+        
     def load_huggingface_concepts(self, concepts: list[str]):
         self.model.textual_inversion_manager.load_huggingface_concepts(concepts)
 

ldm/invoke/CLI.py

@@ -181,7 +181,6 @@ def main():
     # web server loops forever
     if opt.web or opt.gui:
         invoke_ai_web_server_loop(gen, gfpgan, codeformer, esrgan)
-        save_last_used_model(gen.model_name)
         sys.exit(0)
 
     if not infile:
@@ -502,7 +501,6 @@ def main_loop(gen, opt, completer):
     print(
         f'\nGoodbye!\nYou can start InvokeAI again by running the "invoke.bat" (or "invoke.sh") script from {Globals.root}'
     )
-    save_last_used_model(gen.model_name)
 
 
 # TO DO: remove repetitive code and the awkward command.replace() trope
@@ -1300,14 +1298,6 @@ def retrieve_last_used_model()->str:
     with open(model_file_path,'r') as f:
         return f.readline()
 
-def save_last_used_model(model_name:str):
-    """
-    Save name of the last model used.
-    """
-    model_file_path = Path(Globals.root,'.last_model')
-    with open(model_file_path,'w') as f:
-        f.write(model_name)
-
 # This routine performs any patch-ups needed after installation
 def run_patches():
     install_missing_config_files()