Files
2026-02-07 16:02:40 +01:00

550 lines
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Python

"""
LoRA Multi-Merge - Merge multiple LoRAs into a single LoRA file.
Resolves different naming conventions and ranks via concatenation.
"""
import os
import torch
import folder_paths
import comfy.utils
from tqdm import tqdm
from comfy_api.latest import io
from safetensors.torch import save_file
from typing import List, Dict, Tuple, Optional
from .merger_utils import MemoryEfficientSafeOpen, transfer_to_gpu_pinned
from .device_utils import estimate_model_size, prepare_for_large_operation, cleanup_after_operation
from .lora_resize import (
detect_lora_format,
extract_lora_pairs,
detect_lora_rank,
_compile_patterns,
_matches_any_pattern,
_format_lora_key
)
def merge_multi_loras(
lora_paths: List[str],
lora_weights: List[float],
merge_mode: str,
device: str,
save_dtype: torch.dtype,
output_filename: str,
verbose: bool = True,
) -> str:
"""
Merge multiple LoRAs into a single LoRA file.
Modes:
- concatenate: Mathematically sound merge by stacking ranks.
New rank = sum(input ranks). Alpha set to new rank.
- weighted_sum: Weighted sum of A and B weights (Kohya style).
If ranks differ, smaller ones are zero-padded to match the largest rank.
New rank = max(input ranks).
"""
# Estimate memory
total_size_gb = sum(estimate_model_size(p) for p in lora_paths)
if verbose:
print(f"[LoRA Multi-Merge] Preparing memory for {total_size_gb:.2f}GB operation...")
print(f"[LoRA Multi-Merge] Mode: {merge_mode}")
prepare_for_large_operation(total_size_gb * 2.5, torch.device(device))
handlers = [MemoryEfficientSafeOpen(p) for p in lora_paths]
try:
# 1. Analyze all LoRAs
layer_map = {}
lora_infos = []
for i, handler in enumerate(handlers):
keys = handler.keys()
fmt = detect_lora_format(keys)
pairs = extract_lora_pairs(keys, fmt)
rank, alpha = detect_lora_rank(handler, pairs)
info = {
"name": os.path.basename(lora_paths[i]),
"format": fmt,
"pairs": pairs,
"rank": rank,
"alpha": alpha,
"weight": lora_weights[i],
"scale": alpha / rank if rank > 0 else 1.0
}
lora_infos.append(info)
if verbose:
print(f"[LoRA Multi-Merge] LoRA {i+1} ({info['name']}): {len(pairs)} layers, dim={rank}, format={fmt['format']}")
for block_name in pairs.keys():
core = _format_lora_key(block_name)
if core not in layer_map:
layer_map[core] = []
layer_map[core].append(i)
if verbose:
print(f"[LoRA Multi-Merge] Total unique layers after resolving naming: {len(layer_map)}")
output_sd = {}
pbar = comfy.utils.ProgressBar(len(layer_map))
# 2. Merge each core layer
with torch.no_grad():
for core, indices in tqdm(layer_map.items(), desc="Merging layers", unit="layers"):
downs = []
ups = []
is_conv = False
max_rank = 0
# First pass: load and determine max rank
for idx in indices:
info = lora_infos[idx]
handler = handlers[idx]
orig_block = next(b for b in info["pairs"].keys() if _format_lora_key(b) == core)
block_keys = info["pairs"][orig_block]
if "down" not in block_keys or "up" not in block_keys:
continue
t_down = handler.get_tensor(block_keys["down"])
t_up = handler.get_tensor(block_keys["up"])
if device == 'cuda':
t_down = transfer_to_gpu_pinned(t_down, device, torch.float32)
t_up = transfer_to_gpu_pinned(t_up, device, torch.float32)
else:
t_down = t_down.to(device=device, dtype=torch.float32)
t_up = t_up.to(device=device, dtype=torch.float32)
# Store with original info for padding/weighting
is_conv = len(t_down.shape) == 4
current_rank = t_down.shape[0]
max_rank = max(max_rank, current_rank)
# Apply scale immediately for concatenate mode, or keep for later
if merge_mode == "concatenate":
effective_weight = info["weight"] * info["scale"]
t_up = t_up * effective_weight
downs.append((t_down, info))
ups.append((t_up, info))
if not downs:
pbar.update(1)
continue
if merge_mode == "concatenate":
# Stack ranks
merged_down = torch.cat([d[0] for d in downs], dim=0)
merged_up = torch.cat([u[0] for u in ups], dim=1)
new_rank = merged_down.shape[0]
new_alpha = float(new_rank)
else:
# weighted_sum (Kohya style)
# Result = sum( weight_i * Padded(B_i) ), sum( weight_i * Padded(A_i) )
# Note: We apply scale to weights here to normalize different alphas
merged_down = torch.zeros_like(downs[0][0])
# Need to handle different ranks via padding
target_down_shape = list(downs[0][0].shape)
target_down_shape[0] = max_rank
target_up_shape = list(ups[0][0].shape)
target_up_shape[1] = max_rank
merged_down = torch.zeros(target_down_shape, device=device, dtype=torch.float32)
merged_up = torch.zeros(target_up_shape, device=device, dtype=torch.float32)
for (t_d, info_d), (t_u, info_u) in zip(downs, ups):
r = t_d.shape[0]
w = info_d["weight"]
# We also apply sqrt(scale) to both to distribute the scale factor?
# Kohya just uses weights. But to be safe with different alphas,
# we apply scale to the final delta.
# For direct weight merge, we'll just use weights.
if r < max_rank:
# Pad down: [r, in...] -> [max_rank, in...]
pad_d = [0] * (len(t_d.shape) * 2)
pad_d[-1] = max_rank - r # last dim in pad is first dim in tensor (reversed)
# Wait, F.pad uses reverse order of dims.
# For [r, in], padding is (0,0, 0, max_rank-r)
padding_d = [0, 0] * (len(t_d.shape) - 1) + [0, max_rank - r]
t_d = torch.nn.functional.pad(t_d, tuple(padding_d))
# Pad up: [out, r...] -> [out, max_rank...]
# For [out, r], padding is (0, max_rank-r, 0, 0)
padding_u = [0, max_rank - r] + [0, 0] * (len(t_u.shape) - 1)
t_u = torch.nn.functional.pad(t_u, tuple(padding_u))
merged_down += w * t_d
merged_up += w * t_u
new_rank = max_rank
# Alpha is usually max of alphas or same as rank
new_alpha = float(max_rank)
# Store
output_sd[f"{core}.lora_down.weight"] = merged_down.to(save_dtype).cpu().contiguous()
output_sd[f"{core}.lora_up.weight"] = merged_up.to(save_dtype).cpu().contiguous()
output_sd[f"{core}.alpha"] = torch.tensor(new_alpha, dtype=save_dtype)
# Cleanup
del merged_down, merged_up
for d, _ in downs: del d
for u, _ in ups: del u
pbar.update(1)
# 3. Final Summary
if verbose:
matched_stats = {i: 0 for i in range(len(lora_paths))}
for indices in layer_map.values():
for idx in indices:
matched_stats[idx] += 1
print(f"[LoRA Multi-Merge] --- Merge Summary ---")
for i, info in enumerate(lora_infos):
print(f"[LoRA Multi-Merge] LoRA {i+1}: {matched_stats[i]}/{len(info['pairs'])} layers used in merge")
print(f"[LoRA Multi-Merge] Output state dict has {len(output_sd)} tensors")
# 4. Metadata
metadata = {
"ss_training_comment": f"Merged {len(lora_paths)} LoRAs via concatenation",
"ss_network_module": "networks.lora",
}
# 4. Save
output_dir = folder_paths.get_folder_paths("loras")[0]
os.makedirs(output_dir, exist_ok=True)
output_path = os.path.join(output_dir, f"{output_filename.strip()}.safetensors")
save_file(output_sd, output_path, metadata)
if verbose:
print(f"[LoRA Multi-Merge] Saved merged LoRA to {output_path}")
return output_path
finally:
for h in handlers:
h.__exit__(None, None, None)
cleanup_after_operation()
class LoRAMultiMerge(io.ComfyNode):
"""Merge multiple LoRAs into a single LoRA file."""
@classmethod
def define_schema(cls):
return io.Schema(
node_id="LoRAMultiMerge",
display_name="LoRA Multi-Merge",
category="ModelUtils/LoRA/Merge",
description="Merge 1-8 LoRAs into a single LoRA file. This resolves different ranks and naming conventions.",
inputs=[
io.Combo.Input("lora_count", options=[str(i) for i in range(1, 9)], default="2",
tooltip="Number of LoRAs to merge"),
# LoRA 1
io.Combo.Input("lora_1", options=folder_paths.get_filename_list("loras"), tooltip="First LoRA"),
io.Float.Input("weight_1", default=1.0, min=-10.0, max=10.0, step=0.01),
# LoRA 2
io.Combo.Input("lora_2", options=["None"] + folder_paths.get_filename_list("loras"), default="None"),
io.Float.Input("weight_2", default=1.0, min=-10.0, max=10.0, step=0.01),
# LoRA 3
io.Combo.Input("lora_3", options=["None"] + folder_paths.get_filename_list("loras"), default="None"),
io.Float.Input("weight_3", default=1.0, min=-10.0, max=10.0, step=0.01),
# LoRA 4
io.Combo.Input("lora_4", options=["None"] + folder_paths.get_filename_list("loras"), default="None"),
io.Float.Input("weight_4", default=1.0, min=-10.0, max=10.0, step=0.01),
# LoRA 5
io.Combo.Input("lora_5", options=["None"] + folder_paths.get_filename_list("loras"), default="None"),
io.Float.Input("weight_5", default=1.0, min=-10.0, max=10.0, step=0.01),
# LoRA 6
io.Combo.Input("lora_6", options=["None"] + folder_paths.get_filename_list("loras"), default="None"),
io.Float.Input("weight_6", default=1.0, min=-10.0, max=10.0, step=0.01),
# LoRA 7
io.Combo.Input("lora_7", options=["None"] + folder_paths.get_filename_list("loras"), default="None"),
io.Float.Input("weight_7", default=1.0, min=-10.0, max=10.0, step=0.01),
# LoRA 8
io.Combo.Input("lora_8", options=["None"] + folder_paths.get_filename_list("loras"), default="None"),
io.Float.Input("weight_8", default=1.0, min=-10.0, max=10.0, step=0.01),
io.Combo.Input("merge_mode", options=["concatenate", "weighted_sum"], default="concatenate",
tooltip="concatenate: safe, increases rank. weighted_sum: fixed rank (to max input rank), mathematically lossy but standard in Kohya."),
io.String.Input("output_filename", default="merged_lora"),
io.Combo.Input("save_dtype", options=["fp16", "bf16", "fp32"], default="fp16"),
io.Combo.Input("device", options=["cuda", "cpu"], default="cuda"),
],
outputs=[io.String.Output(display_name="output_path")],
is_output_node=True,
)
@classmethod
def execute(cls, lora_count,
lora_1, weight_1, lora_2, weight_2, lora_3, weight_3, lora_4, weight_4,
lora_5, weight_5, lora_6, weight_6, lora_7, weight_7, lora_8, weight_8,
merge_mode, output_filename, save_dtype, device) -> io.NodeOutput:
count = int(lora_count)
names = [lora_1, lora_2, lora_3, lora_4, lora_5, lora_6, lora_7, lora_8]
weights = [weight_1, weight_2, weight_3, weight_4, weight_5, weight_6, weight_7, weight_8]
valid_paths = []
valid_weights = []
for i in range(count):
if names[i] and names[i] != "None":
path = folder_paths.get_full_path_or_raise("loras", names[i])
valid_paths.append(path)
valid_weights.append(weights[i])
if not valid_paths:
raise ValueError("No LoRAs selected for merging.")
dtype = {"fp16": torch.float16, "bf16": torch.bfloat16, "fp32": torch.float32}[save_dtype]
path = merge_multi_loras(
lora_paths=valid_paths,
lora_weights=valid_weights,
merge_mode=merge_mode,
device=device,
save_dtype=dtype,
output_filename=output_filename
)
return io.NodeOutput(path)
class LoRAMultiMergeDARE(io.ComfyNode):
"""Merge multiple LoRAs into a single LoRA file using DARE-Ties method."""
@classmethod
def define_schema(cls):
return io.Schema(
node_id="LoRAMultiMergeDARE",
display_name="LoRA Multi-Merge (DARE-Ties)",
category="ModelUtils/LoRA/Merge",
description="Merge 1-8 LoRAs into a single LoRA file using DARE-Ties. Drops small values and resolves sign conflicts.",
inputs=[
io.Combo.Input("lora_count", options=[str(i) for i in range(1, 9)], default="2"),
# LoRA 1
io.Combo.Input("lora_1", options=folder_paths.get_filename_list("loras"), tooltip="First LoRA"),
io.Float.Input("weight_1", default=1.0, min=-10.0, max=10.0, step=0.01),
# ...
io.Combo.Input("lora_2", options=["None"] + folder_paths.get_filename_list("loras"), default="None"),
io.Float.Input("weight_2", default=1.0, min=-10.0, max=10.0, step=0.01),
io.Combo.Input("lora_3", options=["None"] + folder_paths.get_filename_list("loras"), default="None"),
io.Float.Input("weight_3", default=1.0, min=-10.0, max=10.0, step=0.01),
io.Combo.Input("lora_4", options=["None"] + folder_paths.get_filename_list("loras"), default="None"),
io.Float.Input("weight_4", default=1.0, min=-10.0, max=10.0, step=0.01),
io.Combo.Input("lora_5", options=["None"] + folder_paths.get_filename_list("loras"), default="None"),
io.Float.Input("weight_5", default=1.0, min=-10.0, max=10.0, step=0.01),
io.Combo.Input("lora_6", options=["None"] + folder_paths.get_filename_list("loras"), default="None"),
io.Float.Input("weight_6", default=1.0, min=-10.0, max=10.0, step=0.01),
io.Combo.Input("lora_7", options=["None"] + folder_paths.get_filename_list("loras"), default="None"),
io.Float.Input("weight_7", default=1.0, min=-10.0, max=10.0, step=0.01),
io.Combo.Input("lora_8", options=["None"] + folder_paths.get_filename_list("loras"), default="None"),
io.Float.Input("weight_8", default=1.0, min=-10.0, max=10.0, step=0.01),
io.Float.Input("drop_rate", default=0.1, min=0.0, max=1.0, step=0.01, tooltip="DARE drop rate"),
io.Float.Input("trim_quantile", default=0.2, min=0.0, max=1.0, step=0.01, tooltip="TIES trim quantile (drops smallest values)"),
io.Int.Input("seed", default=42, min=0, max=0xffffffffffffffff),
io.String.Input("output_filename", default="merged_lora_dare"),
io.Combo.Input("save_dtype", options=["fp16", "bf16", "fp32"], default="fp16"),
io.Combo.Input("device", options=["cuda", "cpu"], default="cuda"),
],
outputs=[io.String.Output(display_name="output_path")],
is_output_node=True,
)
@classmethod
def execute(cls, lora_count,
lora_1, weight_1, lora_2, weight_2, lora_3, weight_3, lora_4, weight_4,
lora_5, weight_5, lora_6, weight_6, lora_7, weight_7, lora_8, weight_8,
drop_rate, trim_quantile, seed, output_filename, save_dtype, device) -> io.NodeOutput:
count = int(lora_count)
names = [lora_1, lora_2, lora_3, lora_4, lora_5, lora_6, lora_7, lora_8]
weights = [weight_1, weight_2, weight_3, weight_4, weight_5, weight_6, weight_7, weight_8]
valid_paths = []
valid_weights = []
for i in range(count):
if names[i] and names[i] != "None":
path = folder_paths.get_full_path_or_raise("loras", names[i])
valid_paths.append(path)
valid_weights.append(weights[i])
if not valid_paths:
raise ValueError("No LoRAs selected for merging.")
dtype = {"fp16": torch.float16, "bf16": torch.bfloat16, "fp32": torch.float32}[save_dtype]
path = merge_multi_loras_dare(
lora_paths=valid_paths,
lora_weights=valid_weights,
drop_rate=drop_rate,
trim_quantile=trim_quantile,
seed=seed,
device=device,
save_dtype=dtype,
output_filename=output_filename
)
return io.NodeOutput(path)
def merge_multi_loras_dare(
lora_paths: List[str],
lora_weights: List[float],
drop_rate: float,
trim_quantile: float,
seed: int,
device: str,
save_dtype: torch.dtype,
output_filename: str,
verbose: bool = True,
) -> str:
"""
Merge multiple LoRAs using DARE-Ties method applied to weights.
Different ranks are handled via zero-padding to the max rank.
"""
total_size_gb = sum(estimate_model_size(p) for p in lora_paths)
if verbose:
print(f"[LoRA Multi-Merge DARE] Preparing memory for {total_size_gb:.2f}GB operation...")
print(f"[LoRA Multi-Merge DARE] Drop rate: {drop_rate}, Trim quantile: {trim_quantile}")
prepare_for_large_operation(total_size_gb * 2.5, torch.device(device))
handlers = [MemoryEfficientSafeOpen(p) for p in lora_paths]
rng = torch.Generator(device=device).manual_seed(seed)
try:
# 1. Analyze
layer_map = {}
lora_infos = []
for i, handler in enumerate(handlers):
keys = handler.keys()
fmt = detect_lora_format(keys)
pairs = extract_lora_pairs(keys, fmt)
rank, alpha = detect_lora_rank(handler, pairs)
info = {
"name": os.path.basename(lora_paths[i]),
"pairs": pairs,
"rank": rank,
"alpha": alpha,
"weight": lora_weights[i]
}
lora_infos.append(info)
if verbose:
print(f"[LoRA Multi-Merge DARE] LoRA {i+1} ({info['name']}): {len(pairs)} layers, dim={rank}")
for block_name in pairs.keys():
core = _format_lora_key(block_name)
if core not in layer_map: layer_map[core] = []
layer_map[core].append(i)
if verbose:
print(f"[LoRA Multi-Merge DARE] Total unique layers after resolving naming: {len(layer_map)}")
output_sd = {}
pbar = comfy.utils.ProgressBar(len(layer_map))
# 2. Merge
with torch.no_grad():
for core, indices in tqdm(layer_map.items(), desc="Merging layers (DARE)", unit="layers"):
downs = []
ups = []
max_rank = 0
for idx in indices:
info = lora_infos[idx]
orig_block = next(b for b in info["pairs"].keys() if _format_lora_key(b) == core)
block_keys = info["pairs"][orig_block]
if "down" not in block_keys or "up" not in block_keys: continue
t_d = handlers[idx].get_tensor(block_keys["down"]).to(device=device, dtype=torch.float32)
t_u = handlers[idx].get_tensor(block_keys["up"]).to(device=device, dtype=torch.float32)
max_rank = max(max_rank, t_d.shape[0])
downs.append((t_d, info["weight"]))
ups.append((t_u, info["weight"]))
if not downs:
pbar.update(1)
continue
def process_ties_dare(tensors, weights, dim_to_pad):
# Pad all to max_rank
padded = []
for t, w in tensors:
if t.shape[dim_to_pad] < max_rank:
padding = [0] * (len(t.shape) * 2)
# dim_to_pad 0 (down) -> last pair in pad
# dim_to_pad 1 (up) -> second to last pair in pad
rev_dim = len(t.shape) - 1 - dim_to_pad
padding[rev_dim*2 + 1] = max_rank - t.shape[dim_to_pad]
t = torch.nn.functional.pad(t, tuple(padding))
padded.append(t * w)
# DARE
if drop_rate > 0:
for i in range(len(padded)):
mask = (torch.rand(padded[i].shape, generator=rng, device=device) > drop_rate).float()
padded[i] = (padded[i] * mask) / (1 - drop_rate)
# TIES
# 1. Trim
if trim_quantile > 0:
for i in range(len(padded)):
flat = padded[i].abs().flatten()
k = int(len(flat) * trim_quantile)
if k > 0:
threshold = torch.kthvalue(flat, k).values
padded[i] = torch.where(padded[i].abs() < threshold, torch.zeros_like(padded[i]), padded[i])
# 2. Elect & Merge
stacked = torch.stack(padded) # [N, ...]
signs = torch.sign(stacked)
sum_signs = signs.sum(dim=0)
dominant_sign = torch.sign(sum_signs)
# Filter those matching dominant sign
mask = (signs == dominant_sign) & (dominant_sign != 0)
filtered = torch.where(mask, stacked, torch.zeros_like(stacked))
# Average matching signs
count = mask.sum(dim=0)
result = filtered.sum(dim=0) / torch.clamp(count, min=1.0)
return result
merged_down = process_ties_dare(downs, [1.0]*len(downs), 0)
merged_up = process_ties_dare(ups, [1.0]*len(ups), 1)
output_sd[f"{core}.lora_down.weight"] = merged_down.to(save_dtype).cpu().contiguous()
output_sd[f"{core}.lora_up.weight"] = merged_up.to(save_dtype).cpu().contiguous()
output_sd[f"{core}.alpha"] = torch.tensor(float(max_rank), dtype=save_dtype)
pbar.update(1)
# Final Summary
if verbose:
matched_stats = {i: 0 for i in range(len(lora_paths))}
for indices in layer_map.values():
for idx in indices:
matched_stats[idx] += 1
print(f"[LoRA Multi-Merge DARE] --- Merge Summary ---")
for i, info in enumerate(lora_infos):
print(f"[LoRA Multi-Merge DARE] LoRA {i+1}: {matched_stats[i]}/{len(info['pairs'])} layers used in merge")
print(f"[LoRA Multi-Merge DARE] Output state dict has {len(output_sd)} tensors")
# Save
output_dir = folder_paths.get_folder_paths("loras")[0]
os.makedirs(output_dir, exist_ok=True)
output_path = os.path.join(output_dir, f"{output_filename.strip()}.safetensors")
save_file(output_sd, output_path, {"ss_training_comment": "Merged via DARE-Ties"})
return output_path
finally:
for h in handlers: h.__exit__(None, None, None)
cleanup_after_operation()