Files
smthemex-ComfyUI_StableAvatar/lora_adapter.py
T
2025-08-18 21:33:24 +08:00

134 lines
5.0 KiB
Python

import gc
import os
import torch
from loguru import logger
from safetensors import safe_open
from .envs import *
### https://github.com/ModelTC/LightX2V ####
class WanLoraWrapper:
def __init__(self, wan_model):
self.model = wan_model
self.lora_metadata = {}
self.override_dict = {} # On CPU
def load_lora(self, lora_path, lora_name=None):
if lora_name is None:
lora_name = os.path.basename(lora_path).split(".")[0]
if lora_name in self.lora_metadata:
logger.info(f"LoRA {lora_name} already loaded, skipping...")
return lora_name
self.lora_metadata[lora_name] = {"path": lora_path}
logger.info(f"Registered LoRA metadata for: {lora_name} from {lora_path}")
return lora_name
def _load_lora_file(self, file_path):
with safe_open(file_path, framework="pt") as f:
tensor_dict = {key: f.get_tensor(key).to(GET_DTYPE()) for key in f.keys()}
return tensor_dict
def apply_lora(self, lora_name, alpha=1.0):
if lora_name not in self.lora_metadata:
logger.info(f"LoRA {lora_name} not found. Please load it first.")
# if not hasattr(self.model, "original_weight_dict"):
# logger.error("Model does not have 'original_weight_dict'. Cannot apply LoRA.")
# return False
lora_weights = self._load_lora_file(self.lora_metadata[lora_name]["path"])
weight_dict_=self._apply_lora_weights( self.model.state_dict(), lora_weights, alpha)
m, u = self.model.load_state_dict(weight_dict_, strict=False)
logger.info(f"Applied LoRA: {lora_name} with alpha={alpha}")
del lora_weights
return True
@torch.no_grad()
def _apply_lora_weights(self, weight_dict, lora_weights, alpha):
lora_pairs = {}
lora_diffs = {}
def try_lora_pair(key, prefix, suffix_a, suffix_b, target_suffix):
if key.endswith(suffix_a):
base_name = key[len(prefix) :].replace(suffix_a, target_suffix)
pair_key = key.replace(suffix_a, suffix_b)
if pair_key in lora_weights:
lora_pairs[base_name] = (key, pair_key)
def try_lora_diff(key, prefix, suffix, target_suffix):
if key.endswith(suffix):
base_name = key[len(prefix) :].replace(suffix, target_suffix)
lora_diffs[base_name] = key
prefixs = [
"", # empty prefix
"diffusion_model.",
]
for prefix in prefixs:
for key in lora_weights.keys():
if not key.startswith(prefix):
continue
try_lora_pair(key, prefix, "lora_A.weight", "lora_B.weight", "weight")
try_lora_pair(key, prefix, "lora_down.weight", "lora_up.weight", "weight")
try_lora_diff(key, prefix, "diff", "weight")
try_lora_diff(key, prefix, "diff_b", "bias")
try_lora_diff(key, prefix, "diff_m", "modulation")
applied_count = 0
for name, param in weight_dict.items():
if name in lora_pairs:
if name not in self.override_dict:
self.override_dict[name] = param.clone().cpu()
name_lora_A, name_lora_B = lora_pairs[name]
lora_A = lora_weights[name_lora_A].to(param.device, param.dtype)
lora_B = lora_weights[name_lora_B].to(param.device, param.dtype)
if param.shape == (lora_B.shape[0], lora_A.shape[1]):
param += torch.matmul(lora_B, lora_A) * alpha
applied_count += 1
elif name in lora_diffs:
if name not in self.override_dict:
self.override_dict[name] = param.clone().cpu()
name_diff = lora_diffs[name]
lora_diff = lora_weights[name_diff].to(param.device, param.dtype)
if param.shape == lora_diff.shape:
param += lora_diff * alpha
applied_count += 1
logger.info(f"Applied {applied_count} LoRA weight adjustments")
if applied_count == 0:
logger.info(
"Warning: No LoRA weights were applied. Expected naming conventions: 'diffusion_model.<layer_name>.lora_A.weight' and 'diffusion_model.<layer_name>.lora_B.weight'. Please verify the LoRA weight file."
)
return weight_dict
@torch.no_grad()
def remove_lora(self):
logger.info(f"Removing LoRA ...")
restored_count = 0
for k, v in self.override_dict.items():
self.model.original_weight_dict[k] = v.to(self.model.device)
restored_count += 1
logger.info(f"LoRA removed, restored {restored_count} weights")
self.model._init_weights(self.model.original_weight_dict)
torch.cuda.empty_cache()
gc.collect()
self.lora_metadata = {}
self.override_dict = {}
def list_loaded_loras(self):
return list(self.lora_metadata.keys())