# Copyright 2023 The HuggingFace Team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import importlib
import os
from dataclasses import dataclass
from enum import Enum
from typing import Any, Dict, Optional, Union
import torch
from ..utils import BaseOutput
SCHEDULER_CONFIG_NAME = "scheduler_config.json"
# NOTE: We make this type an enum because it simplifies usage in docs and prevents
# circular imports when used for `_compatibles` within the schedulers module.
# When it's used as a type in pipelines, it really is a Union because the actual
# scheduler instance is passed in.
class KarrasDiffusionSchedulers(Enum):
DDIMScheduler = 1
DDPMScheduler = 2
PNDMScheduler = 3
LMSDiscreteScheduler = 4
EulerDiscreteScheduler = 5
HeunDiscreteScheduler = 6
EulerAncestralDiscreteScheduler = 7
DPMSolverMultistepScheduler = 8
DPMSolverSinglestepScheduler = 9
KDPM2DiscreteScheduler = 10
KDPM2AncestralDiscreteScheduler = 11
DEISMultistepScheduler = 12
UniPCMultistepScheduler = 13
DPMSolverSDEScheduler = 14
@dataclass
class SchedulerOutput(BaseOutput):
"""
Base class for the scheduler's step function output.
Args:
prev_sample (`torch.FloatTensor` of shape `(batch_size, num_channels, height, width)` for images):
Computed sample (x_{t-1}) of previous timestep. `prev_sample` should be used as next model input in the
denoising loop.
"""
prev_sample: torch.FloatTensor
class SchedulerMixin:
"""
Mixin containing common functions for the schedulers.
Class attributes:
- **_compatibles** (`List[str]`) -- A list of classes that are compatible with the parent class, so that
`from_config` can be used from a class different than the one used to save the config (should be overridden
by parent class).
"""
config_name = SCHEDULER_CONFIG_NAME
_compatibles = []
has_compatibles = True
@classmethod
def from_pretrained(
cls,
pretrained_model_name_or_path: Dict[str, Any] = None,
subfolder: Optional[str] = None,
return_unused_kwargs=False,
**kwargs,
):
r"""
Instantiate a Scheduler class from a pre-defined JSON configuration file inside a directory or Hub repo.
Parameters:
pretrained_model_name_or_path (`str` or `os.PathLike`, *optional*):
Can be either:
- A string, the *model id* of a model repo on huggingface.co. Valid model ids should have an
organization name, like `google/ddpm-celebahq-256`.
- A path to a *directory* containing the schedluer configurations saved using
[`~SchedulerMixin.save_pretrained`], e.g., `./my_model_directory/`.
subfolder (`str`, *optional*):
In case the relevant files are located inside a subfolder of the model repo (either remote in
huggingface.co or downloaded locally), you can specify the folder name here.
return_unused_kwargs (`bool`, *optional*, defaults to `False`):
Whether kwargs that are not consumed by the Python class should be returned or not.
cache_dir (`Union[str, os.PathLike]`, *optional*):
Path to a directory in which a downloaded pretrained model configuration should be cached if the
standard cache should not be used.
force_download (`bool`, *optional*, defaults to `False`):
Whether or not to force the (re-)download of the model weights and configuration files, overriding the
cached versions if they exist.
resume_download (`bool`, *optional*, defaults to `False`):
Whether or not to delete incompletely received files. Will attempt to resume the download if such a
file exists.
proxies (`Dict[str, str]`, *optional*):
A dictionary of proxy servers to use by protocol or endpoint, e.g., `{'http': 'foo.bar:3128',
'http://hostname': 'foo.bar:4012'}`. The proxies are used on each request.
output_loading_info(`bool`, *optional*, defaults to `False`):
Whether or not to also return a dictionary containing missing keys, unexpected keys and error messages.
local_files_only(`bool`, *optional*, defaults to `False`):
Whether or not to only look at local files (i.e., do not try to download the model).
use_auth_token (`str` or *bool*, *optional*):
The token to use as HTTP bearer authorization for remote files. If `True`, will use the token generated
when running `transformers-cli login` (stored in `~/.huggingface`).
revision (`str`, *optional*, defaults to `"main"`):
The specific model version to use. It can be a branch name, a tag name, or a commit id, since we use a
git-based system for storing models and other artifacts on huggingface.co, so `revision` can be any
identifier allowed by git.
<Tip>
It is required to be logged in (`huggingface-cli login`) when you want to use private or [gated
models](https://huggingface.co/docs/hub/models-gated#gated-models).
</Tip>
<Tip>
Activate the special ["offline-mode"](https://huggingface.co/transformers/installation.html#offline-mode) to
use this method in a firewalled environment.
</Tip>
"""
config, kwargs, commit_hash = cls.load_config(
pretrained_model_name_or_path=pretrained_model_name_or_path,
subfolder=subfolder,
return_unused_kwargs=True,
return_commit_hash=True,
**kwargs,
)
return cls.from_config(config, return_unused_kwargs=return_unused_kwargs, **kwargs)
def save_pretrained(self, save_directory: Union[str, os.PathLike], push_to_hub: bool = False, **kwargs):
"""
Save a scheduler configuration object to the directory `save_directory`, so that it can be re-loaded using the
[`~SchedulerMixin.from_pretrained`] class method.
Args:
save_directory (`str` or `os.PathLike`):
Directory where the configuration JSON file will be saved (will be created if it does not exist).
"""
self.save_config(save_directory=save_directory, push_to_hub=push_to_hub, **kwargs)
@property
def compatibles(self):
"""
Returns all schedulers that are compatible with this scheduler
Returns:
`List[SchedulerMixin]`: List of compatible schedulers
"""
return self._get_compatibles()
@classmethod
def _get_compatibles(cls):
compatible_classes_str = list(set([cls.__name__] + cls._compatibles))
diffusers_library = importlib.import_module(__name__.split(".")[0])
compatible_classes = [
getattr(diffusers_library, c) for c in compatible_classes_str if hasattr(diffusers_library, c)
]
return compatible_classes