2025-04-22 04:59:47 -04:00

95 lines
2.9 KiB
Python

import logging
from typing import Optional
import torch
import comfy.model_management
from .base import WeightAdapterBase, weight_decompose
class OFTAdapter(WeightAdapterBase):
name = "oft"
def __init__(self, loaded_keys, weights):
self.loaded_keys = loaded_keys
self.weights = weights
@classmethod
def load(
cls,
x: str,
lora: dict[str, torch.Tensor],
alpha: float,
dora_scale: torch.Tensor,
loaded_keys: set[str] = None,
) -> Optional["OFTAdapter"]:
if loaded_keys is None:
loaded_keys = set()
blocks_name = "{}.oft_blocks".format(x)
rescale_name = "{}.rescale".format(x)
blocks = None
if blocks_name in lora.keys():
blocks = lora[blocks_name]
if blocks.ndim == 3:
loaded_keys.add(blocks_name)
rescale = None
if rescale_name in lora.keys():
rescale = lora[rescale_name]
loaded_keys.add(rescale_name)
if blocks is not None:
weights = (blocks, rescale, alpha, dora_scale)
return cls(loaded_keys, weights)
else:
return None
def calculate_weight(
self,
weight,
key,
strength,
strength_model,
offset,
function,
intermediate_dtype=torch.float32,
original_weight=None,
):
v = self.weights
blocks = v[0]
rescale = v[1]
alpha = v[2]
dora_scale = v[3]
blocks = comfy.model_management.cast_to_device(blocks, weight.device, intermediate_dtype)
if rescale is not None:
rescale = comfy.model_management.cast_to_device(rescale, weight.device, intermediate_dtype)
block_num, block_size, *_ = blocks.shape
try:
# Get r
I = torch.eye(block_size, device=blocks.device, dtype=blocks.dtype)
# for Q = -Q^T
q = blocks - blocks.transpose(1, 2)
normed_q = q
if alpha > 0: # alpha in oft/boft is for constraint
q_norm = torch.norm(q) + 1e-8
if q_norm > alpha:
normed_q = q * alpha / q_norm
# use float() to prevent unsupported type in .inverse()
r = (I + normed_q) @ (I - normed_q).float().inverse()
r = r.to(original_weight)
lora_diff = torch.einsum(
"k n m, k n ... -> k m ...",
(r * strength) - strength * I,
original_weight,
)
if dora_scale is not None:
weight = weight_decompose(dora_scale, weight, lora_diff, alpha, strength, intermediate_dtype, function)
else:
weight += function(((strength * alpha) * lora_diff).type(weight.dtype))
except Exception as e:
logging.error("ERROR {} {} {}".format(self.name, key, e))
return weight