enhance support for model switching and editing

- Error checks for invalid model
- Add !del_model command to invoke.py
- Add del_model() method to model_cache
- Autocompleter kept in sync with model addition/subtraction.

ldm/generate.py

@@ -683,8 +683,7 @@ class Generate:
 
         model_data = self.model_cache.get_model(model_name)
         if model_data is None or len(model_data) == 0:
-            print(f'** Model switch failed **')
-            return self.model
+            return None
 
         self.model = model_data['model']
         self.width = model_data['width']

ldm/invoke/args.py

@@ -519,7 +519,7 @@ class Args(object):
             formatter_class=ArgFormatter,
             description=
             """
-            *Image generation:*
+            *Image generation*
                  invoke> a fantastic alien landscape -W576 -H512 -s60 -n4
 
             *postprocessing*
@@ -534,6 +534,13 @@ class Args(object):
             !history lists all the commands issued during the current session.
 
             !NN retrieves the NNth command from the history
+
+            *Model manipulation*
+            !models                                 -- list models in configs/models.yaml
+            !switch <model_name>                    -- switch to model named <model_name>
+            !import_model path/to/weights/file.ckpt -- adds a model to your config
+            !edit_model <model_name>                -- edit a model's description
+            !del_model <model_name>                 -- delete a model
             """
         )
         render_group     = parser.add_argument_group('General rendering')

ldm/invoke/model_cache.py

@@ -73,7 +73,8 @@ class ModelCache(object):
             except Exception as e:
                 print(f'** model {model_name} could not be loaded: {str(e)}')
                 print(f'** restoring {self.current_model}')
-                return self.get_model(self.current_model)
+                self.get_model(self.current_model)
+                return None
         
         self.current_model = model_name
         self._push_newest_model(model_name)
@@ -121,6 +122,16 @@ class ModelCache(object):
             else:
                 print(line)
 
+    def del_model(self, model_name:str) ->str:
+        '''
+        Delete the named model and return the YAML
+        '''
+        omega = self.config
+        del omega[model_name]
+        if model_name in self.stack:
+            self.stack.remove(model_name)
+        return OmegaConf.to_yaml(omega)
+
     def add_model(self, model_name:str, model_attributes:dict, clobber=False) ->str:
         '''
         Update the named model with a dictionary of attributes. Will fail with an

ldm/invoke/readline.py

@@ -53,11 +53,12 @@ COMMANDS = (
     '--log_tokenization','-t',
     '--hires_fix',
     '!fix','!fetch','!history','!search','!clear',
-    '!models','!switch','!import_model','!edit_model'
+    '!models','!switch','!import_model','!edit_model','!del_model',
     )
 MODEL_COMMANDS = (
     '!switch',
     '!edit_model',
+    '!del_model',
     )
 WEIGHT_COMMANDS = (
     '!import_model',
@@ -205,9 +206,24 @@ class Completer(object):
         pydoc.pager('\n'.join(lines))
 
     def set_line(self,line)->None:
+        '''
+        Set the default string displayed in the next line of input.
+        '''
         self.linebuffer = line
         readline.redisplay()
 
+    def add_model(self,model_name:str)->None:
+        '''
+        add a model name to the completion list
+        '''
+        self.models.append(model_name)
+
+    def del_model(self,model_name:str)->None:
+        '''
+        removes a model name from the completion list
+        '''
+        self.models.remove(model_name)
+
     def _seed_completions(self, text, state):
         m = re.search('(-S\s?|--seed[=\s]?)(\d*)',text)
         if m:

scripts/invoke.py

@@ -381,6 +381,15 @@ def do_command(command:str, gen, opt:Args, completer) -> tuple:
         completer.add_history(command)
         operation = None
 
+    elif command.startswith('!del'):
+        path = shlex.split(command)
+        if len(path) < 2:
+            print('** please provide the name of a model')
+        else:
+            del_config(path[1], gen, opt, completer)
+        completer.add_history(command)
+        operation = None
+
     elif command.startswith('!fetch'):
         file_path = command.replace('!fetch ','',1)
         retrieve_dream_command(opt,file_path,completer)
@@ -446,10 +455,23 @@ def add_weights_to_config(model_path:str, gen, opt, completer):
                 done = True
             except:
                 print('** Please enter a valid integer between 64 and 2048')
-
     if write_config_file(opt.conf, gen, model_name, new_config):
-        gen.set_model(model_name)
+        completer.add_model(model_name)
 
+def del_config(model_name:str, gen, opt, completer):
+    current_model = gen.model_name
+    if model_name == current_model:
+        print("** Can't delete active model. !switch to another model first. **")
+        return
+    yaml_str = gen.model_cache.del_model(model_name)
+    
+    tmpfile = os.path.join(os.path.dirname(opt.conf),'new_config.tmp')
+    with open(tmpfile, 'w') as outfile:
+        outfile.write(yaml_str)
+    os.rename(tmpfile,opt.conf)
+    print(f'** {model_name} deleted')
+    completer.del_model(model_name)
+    
 def edit_config(model_name:str, gen, opt, completer):
     config = gen.model_cache.config
     
@@ -467,11 +489,11 @@ def edit_config(model_name:str, gen, opt, completer):
         new_value = input(f'{field}: ')
         new_config[field] = int(new_value) if field in ('width','height') else new_value
     completer.complete_extensions(None)
-
-    if write_config_file(opt.conf, gen, model_name, new_config, clobber=True):
-        gen.set_model(model_name)
+    write_config_file(opt.conf, gen, model_name, new_config, clobber=True)
     
 def write_config_file(conf_path, gen, model_name, new_config, clobber=False):
+    current_model = gen.model_name
+    
     op = 'modify' if clobber else 'import'
     print('\n>> New configuration:')
     print(yaml.dump({model_name:new_config}))
@@ -479,15 +501,24 @@ def write_config_file(conf_path, gen, model_name, new_config, clobber=False):
         return False
 
     try:
+        print('>> Verifying that new model loads...')
         yaml_str = gen.model_cache.add_model(model_name, new_config, clobber)
+        assert gen.set_model(model_name) is not None, 'model failed to load'
     except AssertionError as e:
-        print(f'** configuration failed: {str(e)}')
+        print(f'** aborting **')
+        gen.model_cache.del_model(model_name)
         return False
     
     tmpfile = os.path.join(os.path.dirname(conf_path),'new_config.tmp')
     with open(tmpfile, 'w') as outfile:
         outfile.write(yaml_str)
     os.rename(tmpfile,conf_path)
+
+    do_switch = input(f'Keep model loaded? [y]')
+    if len(do_switch)==0 or do_switch[0] in ('y','Y'):
+        pass
+    else:
+        gen.set_model(current_model)
     return True
 
 def do_postprocess (gen, opt, callback):