From edba28daccc56c9fc5eb6e2230de233a4a93e11f Mon Sep 17 00:00:00 2001
From: Haoming <hmstudy02@gmail.com>
Date: Fri, 20 Feb 2026 19:39:07 +0800
Subject: [PATCH] fast refiner

---
 modules/processing_scripts/refiner.py | 28 ++++++++++++++++++++++++++
 modules/sd_samplers_common.py         | 29 +++++++++++++++++++++++++++
 modules/shared_options.py             |  1 +
 3 files changed, 58 insertions(+)

diff --git a/modules/processing_scripts/refiner.py b/modules/processing_scripts/refiner.py
index 4b562da7..76062448 100644
--- a/modules/processing_scripts/refiner.py
+++ b/modules/processing_scripts/refiner.py
@@ -1,4 +1,5 @@
 import gradio as gr
+import torch
 
 from modules import scripts, sd_models
 from modules.infotext_utils import PasteField
@@ -53,3 +54,30 @@ class ScriptRefiner(scripts.ScriptBuiltinUI):
         else:
             p.refiner_checkpoint = refiner_checkpoint
             p.refiner_switch_at = refiner_switch_at
+
+    @torch.inference_mode()
+    def postprocess(self, *args, **kwargs):
+        from modules import sd_samplers_common
+
+        if sd_samplers_common.ORIGINAL_CHECKPOINT is None:
+            return
+
+        import huggingface_guess
+
+        from backend.loader import preprocess_state_dict
+        from backend.state_dict import load_state_dict, try_filter_state_dict
+        from backend.utils import load_torch_file
+        from modules_forge.main_entry import logger
+
+        model = sd_models.model_data.get_sd_model().forge_objects.unet.model.diffusion_model
+
+        sd = load_torch_file(sd_samplers_common.ORIGINAL_CHECKPOINT)
+        sd = preprocess_state_dict(sd)
+
+        guess = huggingface_guess.guess(sd)
+
+        sd = try_filter_state_dict(sd, guess.unet_key_prefix)
+
+        logger.info("Restoring state_dict...")
+        sd_samplers_common.ORIGINAL_CHECKPOINT = None
+        load_state_dict(model, sd)
diff --git a/modules/sd_samplers_common.py b/modules/sd_samplers_common.py
index 413a3f4d..923265a3 100644
--- a/modules/sd_samplers_common.py
+++ b/modules/sd_samplers_common.py
@@ -185,6 +185,9 @@ def apply_lora_for_refiner(loras: list[extra_networks.ExtraNetworkParams]):
     return result
 
 
+ORIGINAL_CHECKPOINT: str = None
+
+
 def apply_refiner(cfg_denoiser, x, sigma):
     if not (refiner_switch_at := cfg_denoiser.p.refiner_switch_at):
         return False
@@ -196,6 +199,10 @@ def apply_refiner(cfg_denoiser, x, sigma):
         if float(sigma) > refiner_switch_at:
             return False
 
+    global ORIGINAL_CHECKPOINT
+    if ORIGINAL_CHECKPOINT is not None:
+        return False
+
     refiner_checkpoint_info = cfg_denoiser.p.refiner_checkpoint_info
     if refiner_checkpoint_info is None or shared.sd_model.sd_checkpoint_info == refiner_checkpoint_info:
         return False
@@ -207,6 +214,28 @@ def apply_refiner(cfg_denoiser, x, sigma):
     cfg_denoiser.p.extra_generation_params["Refiner"] = refiner_checkpoint_info.short_title
     cfg_denoiser.p.extra_generation_params["Refiner switch at"] = refiner_switch_at
 
+    if opts.refiner_fast_sd:
+        import huggingface_guess
+
+        from backend.loader import preprocess_state_dict
+        from backend.state_dict import load_state_dict, try_filter_state_dict
+        from backend.utils import load_torch_file
+
+        model = sd_models.model_data.get_sd_model().forge_objects.unet.model.diffusion_model
+
+        sd = load_torch_file(refiner_checkpoint_info.filename)
+        sd = preprocess_state_dict(sd)
+
+        guess = huggingface_guess.guess(sd)
+
+        sd = try_filter_state_dict(sd, guess.unet_key_prefix)
+
+        main_entry.logger.info("Reloading state_dict...")
+        ORIGINAL_CHECKPOINT = shared.sd_model.sd_checkpoint_info.filename
+        load_state_dict(model, sd)
+
+        return True
+
     sampling_cleanup(sd_models.model_data.get_sd_model().forge_objects.unet)
 
     original_checkpoint = getattr(shared.opts, "sd_model_checkpoint")
diff --git a/modules/shared_options.py b/modules/shared_options.py
index b73a81ae..b0da9fba 100644
--- a/modules/shared_options.py
+++ b/modules/shared_options.py
@@ -369,6 +369,7 @@ options_templates.update(
         ("refiner", "Refiner", "sd"),
         {
             "show_refiner": OptionInfo(False, "Display the Refiner Accordion").info("Refiner swaps the model in the middle of generation; useful for Wan 2.2 <b>High Noise</b> to <b>Low Noise</b> switching").needs_reload_ui(),
+            "refiner_fast_sd": OptionInfo(False, 'Reload "state_dict" Only').info("EXPERIMENTAL").info("does not support LoRA currently"),
             "refiner_use_steps": OptionInfo(False, 'Switch based on "steps" instead').info('by default, Refiner swaps the model based on "sigmas" to match <a href="https://www.reddit.com/r/StableDiffusion/comments/1n3qns1/wan_22_how_many_highsteps_are_needed_a_simple/">Wan 2.2</a> \'s behavior'),
             "refiner_lora_replacement": OptionInfo(
                 "high_noise=low_noise",