Files
ai-toolkit/toolkit/models/DoRA.py
T

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3.4 KiB
Python

#based off https://github.com/catid/dora/blob/main/dora.py
import math
import torch
import torch.nn as nn
import torch.nn.functional as F
from typing import TYPE_CHECKING, Union, List
from toolkit.network_mixins import ToolkitModuleMixin, ExtractableModuleMixin
if TYPE_CHECKING:
from toolkit.lora_special import LoRASpecialNetwork
# diffusers specific stuff
LINEAR_MODULES = [
'Linear',
'LoRACompatibleLinear'
# 'GroupNorm',
]
CONV_MODULES = [
'Conv2d',
'LoRACompatibleConv'
]
class DoRAModule(ToolkitModuleMixin, ExtractableModuleMixin, torch.nn.Module):
# def __init__(self, d_in, d_out, rank=4, weight=None, bias=None):
def __init__(
self,
lora_name,
org_module: torch.nn.Module,
multiplier=1.0,
lora_dim=4,
alpha=1,
dropout=None,
rank_dropout=None,
module_dropout=None,
network: 'LoRASpecialNetwork' = None,
use_bias: bool = False,
**kwargs
):
self.can_merge_in = False
"""if alpha == 0 or None, alpha is rank (no scaling)."""
ToolkitModuleMixin.__init__(self, network=network)
torch.nn.Module.__init__(self)
self.lora_name = lora_name
self.scalar = torch.tensor(1.0)
self.lora_dim = lora_dim
if org_module.__class__.__name__ in CONV_MODULES:
raise NotImplementedError("Convolutional layers are not supported yet")
if type(alpha) == torch.Tensor:
alpha = alpha.detach().float().numpy() # without casting, bf16 causes error
alpha = self.lora_dim if alpha is None or alpha == 0 else alpha
self.scale = alpha / self.lora_dim
# self.register_buffer("alpha", torch.tensor(alpha)) # 定数として扱える eng: treat as constant
self.multiplier: Union[float, List[float]] = multiplier
# wrap the original module so it doesn't get weights updated
self.org_module = [org_module]
self.dropout = dropout
self.rank_dropout = rank_dropout
self.module_dropout = module_dropout
self.is_checkpointing = False
# m = Magnitude column-wise across output dimension
self.magnitude = nn.Parameter(self.get_orig_weight().norm(p=2, dim=0, keepdim=True))
d_out = org_module.out_features
d_in = org_module.in_features
std_dev = 1 / torch.sqrt(torch.tensor(self.lora_dim).float())
self.lora_up = nn.Parameter(torch.randn(d_out, self.lora_dim) * std_dev)
self.lora_down = nn.Parameter(torch.zeros(self.lora_dim, d_in))
def apply_to(self):
self.org_forward = self.org_module[0].forward
self.org_module[0].forward = self.forward
# del self.org_module
def get_orig_weight(self):
return self.org_module[0].weight.data.detach()
def get_orig_bias(self):
if hasattr(self.org_module[0], 'bias') and self.org_module[0].bias is not None:
return self.org_module[0].bias.data.detach()
return None
def dora_forward(self, x, *args, **kwargs):
lora = torch.matmul(self.lora_up, self.lora_down)
adapted = self.get_orig_weight() + lora
column_norm = adapted.norm(p=2, dim=0, keepdim=True)
norm_adapted = adapted / column_norm
calc_weights = self.magnitude * norm_adapted
return F.linear(x, calc_weights, self.get_orig_bias())