Restore --peft support

modeling/inference_models/hf_torch.py

@@ -262,6 +262,40 @@ class HFTorchInferenceModel(HFInferenceModel):
         new_sample.old_sample = transformers.GenerationMixin.sample
         use_core_manipulations.sample = new_sample
 
+        # PEFT Loading. This MUST be done after all save_pretrained calls are
+        # finished on the main model.
+        if utils.args.peft:
+            from peft import PeftModel, PeftConfig
+            local_peft_dir = os.path.join(m_self.get_local_model_path(), "peft")
+
+            # Make PEFT dir if it doesn't exist
+            try:
+                os.makedirs(local_peft_dir)
+            except FileExistsError:
+                pass
+
+            peft_local_path = os.path.join(local_peft_dir, utils.args.peft.replace("/", "_"))
+            logger.debug(f"Loading PEFT '{utils.args.peft}', possible local path is '{peft_local_path}'.")
+
+            peft_installed_locally = True
+            possible_peft_locations = [peft_local_path, utils.args.peft]
+
+            for i, location in enumerate(possible_peft_locations):
+                try:
+                    m_self.model = PeftModel.from_pretrained(m_self.model, location)
+                    logger.debug(f"Loaded PEFT at '{location}'")
+                    break
+                except ValueError:
+                    peft_installed_locally = False
+                    if i == len(possible_peft_locations) - 1:
+                        raise RuntimeError(f"Unable to load PeftModel for given name '{utils.args.peft}'. Does it exist?")
+                except RuntimeError:
+                    raise RuntimeError("Error while loading PeftModel. Are you using the correct model?")
+
+            if not peft_installed_locally:
+                logger.debug(f"PEFT not saved to models folder; saving to '{peft_local_path}'")
+                m_self.model.save_pretrained(peft_local_path)
+
         return super()._post_load()
 
     def _raw_generate(