ComfyUI/comfy_extras/nodes_sage3.py
2026-01-06 13:54:27 +08:00

79 lines
2.5 KiB
Python

from typing import Callable
import torch
from typing_extensions import override
from comfy.ldm.modules.attention import get_attention_function
from comfy.model_patcher import ModelPatcher
from comfy_api.latest import ComfyExtension, io
from server import PromptServer
class Sage3PatchModel(io.ComfyNode):
@classmethod
def define_schema(cls):
return io.Schema(
node_id="Sage3PatchModel",
display_name="Patch SageAttention 3",
description="Patch the model to use `attention3_sage` during the middle blocks and steps, keeping the default attention function for the first/last blocks and steps",
category="_for_testing",
inputs=[
io.Model.Input("model"),
],
outputs=[io.Model.Output()],
is_experimental=True,
)
@classmethod
def execute(cls, model: ModelPatcher) -> io.NodeOutput:
sage3: Callable | None = get_attention_function("sage3", default=None)
if sage3 is None:
PromptServer.instance.send_progress_text(
"`sageattn3` is not installed / available...",
cls.hidden.unique_id,
)
return io.NodeOutput(model)
def attention_override(func: Callable, *args, **kwargs):
transformer_options: dict = kwargs.get("transformer_options", {})
block_index: int = transformer_options.get("block_index", 0)
total_blocks: int = transformer_options.get("total_blocks", 1)
if block_index == 0 or block_index >= (total_blocks - 1):
return func(*args, **kwargs)
sample_sigmas: torch.Tensor = transformer_options["sample_sigmas"]
sigmas: torch.Tensor = transformer_options["sigmas"]
total_steps: int = sample_sigmas.size(0)
step: int = 0
for i in range(total_steps):
if torch.allclose(sample_sigmas[i], sigmas):
step = i
break
if step == 0 or step >= (total_steps - 1):
return func(*args, **kwargs)
return sage3(*args, **kwargs)
model = model.clone()
model.model_options["transformer_options"][
"optimized_attention_override"
] = attention_override
return io.NodeOutput(model)
class Sage3Extension(ComfyExtension):
@override
async def get_node_list(self) -> list[type[io.ComfyNode]]:
return [Sage3PatchModel]
async def comfy_entrypoint():
return Sage3Extension()