aboutsummaryrefslogtreecommitdiffstats
path: root/extensions-builtin/Lora/network_oft.py
blob: 3034a407eb35514e39d4bdcf7158a3b74badb2b6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
import torch
import network


class ModuleTypeOFT(network.ModuleType):
    def create_module(self, net: network.Network, weights: network.NetworkWeights):
        if all(x in weights.w for x in ["oft_blocks"]):
            return NetworkModuleOFT(net, weights)

        return None

# adapted from kohya's implementation https://github.com/kohya-ss/sd-scripts/blob/main/networks/oft.py
class NetworkModuleOFT(network.NetworkModule):
    def __init__(self,  net: network.Network, weights: network.NetworkWeights):

        super().__init__(net, weights)

        self.oft_blocks = weights.w["oft_blocks"]
        self.alpha = weights.w["alpha"]
        self.dim = self.oft_blocks.shape[0]
        self.num_blocks = self.dim

        if "Linear" in self.sd_module.__class__.__name__:
            self.out_dim = self.sd_module.out_features
        elif "Conv" in self.sd_module.__class__.__name__:
            self.out_dim = self.sd_module.out_channels

        self.constraint = self.alpha * self.out_dim
        self.block_size = self.out_dim // self.num_blocks

        self.org_module: list[torch.Module] = [self.sd_module]

    def merge_weight(self, R_weight, org_weight):
        R_weight = R_weight.to(org_weight.device, dtype=org_weight.dtype)
        if org_weight.dim() == 4:
            weight = torch.einsum("oihw, op -> pihw", org_weight, R_weight)
        else:
            weight = torch.einsum("oi, op -> pi", org_weight, R_weight)
        return weight

    def get_weight(self, oft_blocks, multiplier=None):
        constraint = self.constraint.to(oft_blocks.device, dtype=oft_blocks.dtype)

        block_Q = oft_blocks - oft_blocks.transpose(1, 2)
        norm_Q = torch.norm(block_Q.flatten())
        new_norm_Q = torch.clamp(norm_Q, max=constraint)
        block_Q = block_Q * ((new_norm_Q + 1e-8) / (norm_Q + 1e-8))
        m_I = torch.eye(self.block_size, device=oft_blocks.device).unsqueeze(0).repeat(self.num_blocks, 1, 1)
        block_R = torch.matmul(m_I + block_Q, (m_I - block_Q).inverse())

        block_R_weighted = multiplier * block_R + (1 - multiplier) * m_I
        R = torch.block_diag(*block_R_weighted)

        return R

    def calc_updown(self, orig_weight):
        R = self.get_weight(self.oft_blocks, self.multiplier())
        merged_weight = self.merge_weight(R, orig_weight)

        updown = merged_weight.to(orig_weight.device, dtype=orig_weight.dtype) - orig_weight
        output_shape = orig_weight.shape
        orig_weight = orig_weight

        return self.finalize_updown(updown, orig_weight, output_shape)