Upload train_with_fixes.py with huggingface_hub

train_with_fixes.py

@@ -0,0 +1,1700 @@
+#!/usr/bin/env python
+# coding=utf-8
+# Copyright 2023 The HuggingFace Inc. 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
+
+import argparse
+import gc
+import itertools
+import logging
+import math
+import os
+import shutil
+import warnings
+from pathlib import Path
+
+import numpy as np
+import torch
+import torch.nn.functional as F
+import torch.utils.checkpoint
+import transformers
+from accelerate import Accelerator
+from accelerate.logging import get_logger
+from accelerate.utils import DistributedDataParallelKwargs, ProjectConfiguration, set_seed
+from huggingface_hub import create_repo, upload_folder
+from huggingface_hub.utils import insecure_hashlib
+from packaging import version
+from peft import LoraConfig
+from peft.utils import get_peft_model_state_dict
+from PIL import Image
+from PIL.ImageOps import exif_transpose
+from torch.utils.data import Dataset
+from torchvision import transforms
+from tqdm.auto import tqdm
+from transformers import AutoTokenizer, PretrainedConfig
+
+import diffusers
+from diffusers import (
+    AutoencoderKL,
+    DDPMScheduler,
+    DPMSolverMultistepScheduler,
+    StableDiffusionXLPipeline,
+    UNet2DConditionModel,
+)
+from diffusers.loaders import LoraLoaderMixin
+from diffusers.optimization import get_scheduler
+from diffusers.training_utils import compute_snr
+from diffusers.utils import check_min_version, is_wandb_available
+from diffusers.utils.import_utils import is_xformers_available
+
+
+# Will error if the minimal version of diffusers is not installed. Remove at your own risks.
+check_min_version("0.25.0.dev0")
+
+logger = get_logger(__name__)
+
+
+def save_model_card(
+    repo_id: str,
+    images=None,
+    base_model=str,
+    train_text_encoder=False,
+    instance_prompt=str,
+    validation_prompt=str,
+    repo_folder=None,
+    vae_path=None,
+):
+    img_str = "widget:\n" if images else ""
+    for i, image in enumerate(images):
+        image.save(os.path.join(repo_folder, f"image_{i}.png"))
+        img_str += f"""
+        - text: '{validation_prompt if validation_prompt else ' ' }'
+          output:
+            url:
+                "image_{i}.png"
+        """
+
+    yaml = f"""
+---
+tags:
+- stable-diffusion-xl
+- stable-diffusion-xl-diffusers
+- text-to-image
+- diffusers
+- lora
+- template:sd-lora
+{img_str}
+base_model: {base_model}
+instance_prompt: {instance_prompt}
+license: openrail++
+---
+    """
+
+    model_card = f"""
+# SDXL LoRA DreamBooth - {repo_id}
+
+<Gallery />
+
+## Model description
+
+These are {repo_id} LoRA adaption weights for {base_model}.
+
+The weights were trained  using [DreamBooth](https://dreambooth.github.io/).
+
+LoRA for the text encoder was enabled: {train_text_encoder}.
+
+Special VAE used for training: {vae_path}.
+
+## Trigger words
+
+You should use {instance_prompt} to trigger the image generation.
+
+## Download model
+
+Weights for this model are available in Safetensors format.
+
+[Download]({repo_id}/tree/main) them in the Files & versions tab.
+
+"""
+    with open(os.path.join(repo_folder, "README.md"), "w") as f:
+        f.write(yaml + model_card)
+
+
+def import_model_class_from_model_name_or_path(
+    pretrained_model_name_or_path: str, revision: str, subfolder: str = "text_encoder"
+):
+    text_encoder_config = PretrainedConfig.from_pretrained(
+        pretrained_model_name_or_path, subfolder=subfolder, revision=revision
+    )
+    model_class = text_encoder_config.architectures[0]
+
+    if model_class == "CLIPTextModel":
+        from transformers import CLIPTextModel
+
+        return CLIPTextModel
+    elif model_class == "CLIPTextModelWithProjection":
+        from transformers import CLIPTextModelWithProjection
+
+        return CLIPTextModelWithProjection
+    else:
+        raise ValueError(f"{model_class} is not supported.")
+
+
+def parse_args(input_args=None):
+    parser = argparse.ArgumentParser(description="Simple example of a training script.")
+    parser.add_argument(
+        "--pretrained_model_name_or_path",
+        type=str,
+        default=None,
+        required=True,
+        help="Path to pretrained model or model identifier from huggingface.co/models.",
+    )
+    parser.add_argument(
+        "--pretrained_vae_model_name_or_path",
+        type=str,
+        default=None,
+        help="Path to pretrained VAE model with better numerical stability. More details: https://github.com/huggingface/diffusers/pull/4038.",
+    )
+    parser.add_argument(
+        "--revision",
+        type=str,
+        default=None,
+        required=False,
+        help="Revision of pretrained model identifier from huggingface.co/models.",
+    )
+    parser.add_argument(
+        "--variant",
+        type=str,
+        default=None,
+        help="Variant of the model files of the pretrained model identifier from huggingface.co/models, 'e.g.' fp16",
+    )
+    parser.add_argument(
+        "--dataset_name",
+        type=str,
+        default=None,
+        help=(
+            "The name of the Dataset (from the HuggingFace hub) containing the training data of instance images (could be your own, possibly private,"
+            " dataset). It can also be a path pointing to a local copy of a dataset in your filesystem,"
+            " or to a folder containing files that 🤗 Datasets can understand."
+        ),
+    )
+    parser.add_argument(
+        "--dataset_config_name",
+        type=str,
+        default=None,
+        help="The config of the Dataset, leave as None if there's only one config.",
+    )
+    parser.add_argument(
+        "--instance_data_dir",
+        type=str,
+        default=None,
+        help=("A folder containing the training data. "),
+    )
+
+    parser.add_argument(
+        "--cache_dir",
+        type=str,
+        default=None,
+        help="The directory where the downloaded models and datasets will be stored.",
+    )
+
+    parser.add_argument(
+        "--image_column",
+        type=str,
+        default="image",
+        help="The column of the dataset containing the target image. By "
+        "default, the standard Image Dataset maps out 'file_name' "
+        "to 'image'.",
+    )
+    parser.add_argument(
+        "--caption_column",
+        type=str,
+        default=None,
+        help="The column of the dataset containing the instance prompt for each image",
+    )
+
+    parser.add_argument("--repeats", type=int, default=1, help="How many times to repeat the training data.")
+
+    parser.add_argument(
+        "--class_data_dir",
+        type=str,
+        default=None,
+        required=False,
+        help="A folder containing the training data of class images.",
+    )
+    parser.add_argument(
+        "--instance_prompt",
+        type=str,
+        default=None,
+        required=True,
+        help="The prompt with identifier specifying the instance, e.g. 'photo of a TOK dog', 'in the style of TOK'",
+    )
+    parser.add_argument(
+        "--class_prompt",
+        type=str,
+        default=None,
+        help="The prompt to specify images in the same class as provided instance images.",
+    )
+    parser.add_argument(
+        "--validation_prompt",
+        type=str,
+        default=None,
+        help="A prompt that is used during validation to verify that the model is learning.",
+    )
+    parser.add_argument(
+        "--num_validation_images",
+        type=int,
+        default=4,
+        help="Number of images that should be generated during validation with `validation_prompt`.",
+    )
+    parser.add_argument(
+        "--validation_epochs",
+        type=int,
+        default=50,
+        help=(
+            "Run dreambooth validation every X epochs. Dreambooth validation consists of running the prompt"
+            " `args.validation_prompt` multiple times: `args.num_validation_images`."
+        ),
+    )
+    parser.add_argument(
+        "--with_prior_preservation",
+        default=False,
+        action="store_true",
+        help="Flag to add prior preservation loss.",
+    )
+    parser.add_argument("--prior_loss_weight", type=float, default=1.0, help="The weight of prior preservation loss.")
+    parser.add_argument(
+        "--num_class_images",
+        type=int,
+        default=100,
+        help=(
+            "Minimal class images for prior preservation loss. If there are not enough images already present in"
+            " class_data_dir, additional images will be sampled with class_prompt."
+        ),
+    )
+    parser.add_argument(
+        "--output_dir",
+        type=str,
+        default="lora-dreambooth-model",
+        help="The output directory where the model predictions and checkpoints will be written.",
+    )
+    parser.add_argument("--seed", type=int, default=None, help="A seed for reproducible training.")
+    parser.add_argument(
+        "--resolution",
+        type=int,
+        default=1024,
+        help=(
+            "The resolution for input images, all the images in the train/validation dataset will be resized to this"
+            " resolution"
+        ),
+    )
+    parser.add_argument(
+        "--crops_coords_top_left_h",
+        type=int,
+        default=0,
+        help=("Coordinate for (the height) to be included in the crop coordinate embeddings needed by SDXL UNet."),
+    )
+    parser.add_argument(
+        "--crops_coords_top_left_w",
+        type=int,
+        default=0,
+        help=("Coordinate for (the height) to be included in the crop coordinate embeddings needed by SDXL UNet."),
+    )
+    parser.add_argument(
+        "--center_crop",
+        default=False,
+        action="store_true",
+        help=(
+            "Whether to center crop the input images to the resolution. If not set, the images will be randomly"
+            " cropped. The images will be resized to the resolution first before cropping."
+        ),
+    )
+    parser.add_argument(
+        "--train_text_encoder",
+        action="store_true",
+        help="Whether to train the text encoder. If set, the text encoder should be float32 precision.",
+    )
+    parser.add_argument(
+        "--train_batch_size", type=int, default=4, help="Batch size (per device) for the training dataloader."
+    )
+    parser.add_argument(
+        "--sample_batch_size", type=int, default=4, help="Batch size (per device) for sampling images."
+    )
+    parser.add_argument("--num_train_epochs", type=int, default=1)
+    parser.add_argument(
+        "--max_train_steps",
+        type=int,
+        default=None,
+        help="Total number of training steps to perform.  If provided, overrides num_train_epochs.",
+    )
+    parser.add_argument(
+        "--checkpointing_steps",
+        type=int,
+        default=500,
+        help=(
+            "Save a checkpoint of the training state every X updates. These checkpoints can be used both as final"
+            " checkpoints in case they are better than the last checkpoint, and are also suitable for resuming"
+            " training using `--resume_from_checkpoint`."
+        ),
+    )
+    parser.add_argument(
+        "--checkpoints_total_limit",
+        type=int,
+        default=None,
+        help=("Max number of checkpoints to store."),
+    )
+    parser.add_argument(
+        "--resume_from_checkpoint",
+        type=str,
+        default=None,
+        help=(
+            "Whether training should be resumed from a previous checkpoint. Use a path saved by"
+            ' `--checkpointing_steps`, or `"latest"` to automatically select the last available checkpoint.'
+        ),
+    )
+    parser.add_argument(
+        "--gradient_accumulation_steps",
+        type=int,
+        default=1,
+        help="Number of updates steps to accumulate before performing a backward/update pass.",
+    )
+    parser.add_argument(
+        "--gradient_checkpointing",
+        action="store_true",
+        help="Whether or not to use gradient checkpointing to save memory at the expense of slower backward pass.",
+    )
+    parser.add_argument(
+        "--learning_rate",
+        type=float,
+        default=1e-4,
+        help="Initial learning rate (after the potential warmup period) to use.",
+    )
+
+    parser.add_argument(
+        "--text_encoder_lr",
+        type=float,
+        default=5e-6,
+        help="Text encoder learning rate to use.",
+    )
+    parser.add_argument(
+        "--scale_lr",
+        action="store_true",
+        default=False,
+        help="Scale the learning rate by the number of GPUs, gradient accumulation steps, and batch size.",
+    )
+    parser.add_argument(
+        "--lr_scheduler",
+        type=str,
+        default="constant",
+        help=(
+            'The scheduler type to use. Choose between ["linear", "cosine", "cosine_with_restarts", "polynomial",'
+            ' "constant", "constant_with_warmup"]'
+        ),
+    )
+
+    parser.add_argument(
+        "--snr_gamma",
+        type=float,
+        default=None,
+        help="SNR weighting gamma to be used if rebalancing the loss. Recommended value is 5.0. "
+        "More details here: https://arxiv.org/abs/2303.09556.",
+    )
+    parser.add_argument(
+        "--lr_warmup_steps", type=int, default=500, help="Number of steps for the warmup in the lr scheduler."
+    )
+    parser.add_argument(
+        "--lr_num_cycles",
+        type=int,
+        default=1,
+        help="Number of hard resets of the lr in cosine_with_restarts scheduler.",
+    )
+    parser.add_argument("--lr_power", type=float, default=1.0, help="Power factor of the polynomial scheduler.")
+    parser.add_argument(
+        "--dataloader_num_workers",
+        type=int,
+        default=0,
+        help=(
+            "Number of subprocesses to use for data loading. 0 means that the data will be loaded in the main process."
+        ),
+    )
+
+    parser.add_argument(
+        "--optimizer",
+        type=str,
+        default="AdamW",
+        help=('The optimizer type to use. Choose between ["AdamW", "prodigy"]'),
+    )
+
+    parser.add_argument(
+        "--use_8bit_adam",
+        action="store_true",
+        help="Whether or not to use 8-bit Adam from bitsandbytes. Ignored if optimizer is not set to AdamW",
+    )
+
+    parser.add_argument(
+        "--adam_beta1", type=float, default=0.9, help="The beta1 parameter for the Adam and Prodigy optimizers."
+    )
+    parser.add_argument(
+        "--adam_beta2", type=float, default=0.999, help="The beta2 parameter for the Adam and Prodigy optimizers."
+    )
+    parser.add_argument(
+        "--prodigy_beta3",
+        type=float,
+        default=None,
+        help="coefficients for computing the Prodidy stepsize using running averages. If set to None, "
+        "uses the value of square root of beta2. Ignored if optimizer is adamW",
+    )
+    parser.add_argument("--prodigy_decouple", type=bool, default=True, help="Use AdamW style decoupled weight decay")
+    parser.add_argument("--adam_weight_decay", type=float, default=1e-04, help="Weight decay to use for unet params")
+    parser.add_argument(
+        "--adam_weight_decay_text_encoder", type=float, default=1e-03, help="Weight decay to use for text_encoder"
+    )
+
+    parser.add_argument(
+        "--adam_epsilon",
+        type=float,
+        default=1e-08,
+        help="Epsilon value for the Adam optimizer and Prodigy optimizers.",
+    )
+
+    parser.add_argument(
+        "--prodigy_use_bias_correction",
+        type=bool,
+        default=True,
+        help="Turn on Adam's bias correction. True by default. Ignored if optimizer is adamW",
+    )
+    parser.add_argument(
+        "--prodigy_safeguard_warmup",
+        type=bool,
+        default=True,
+        help="Remove lr from the denominator of D estimate to avoid issues during warm-up stage. True by default. "
+        "Ignored if optimizer is adamW",
+    )
+    parser.add_argument("--max_grad_norm", default=1.0, type=float, help="Max gradient norm.")
+    parser.add_argument("--push_to_hub", action="store_true", help="Whether or not to push the model to the Hub.")
+    parser.add_argument("--hub_token", type=str, default=None, help="The token to use to push to the Model Hub.")
+    parser.add_argument(
+        "--hub_model_id",
+        type=str,
+        default=None,
+        help="The name of the repository to keep in sync with the local `output_dir`.",
+    )
+    parser.add_argument(
+        "--logging_dir",
+        type=str,
+        default="logs",
+        help=(
+            "[TensorBoard](https://www.tensorflow.org/tensorboard) log directory. Will default to"
+            " *output_dir/runs/**CURRENT_DATETIME_HOSTNAME***."
+        ),
+    )
+    parser.add_argument(
+        "--allow_tf32",
+        action="store_true",
+        help=(
+            "Whether or not to allow TF32 on Ampere GPUs. Can be used to speed up training. For more information, see"
+            " https://pytorch.org/docs/stable/notes/cuda.html#tensorfloat-32-tf32-on-ampere-devices"
+        ),
+    )
+    parser.add_argument(
+        "--report_to",
+        type=str,
+        default="tensorboard",
+        help=(
+            'The integration to report the results and logs to. Supported platforms are `"tensorboard"`'
+            ' (default), `"wandb"` and `"comet_ml"`. Use `"all"` to report to all integrations.'
+        ),
+    )
+    parser.add_argument(
+        "--mixed_precision",
+        type=str,
+        default=None,
+        choices=["no", "fp16", "bf16"],
+        help=(
+            "Whether to use mixed precision. Choose between fp16 and bf16 (bfloat16). Bf16 requires PyTorch >="
+            " 1.10.and an Nvidia Ampere GPU.  Default to the value of accelerate config of the current system or the"
+            " flag passed with the `accelerate.launch` command. Use this argument to override the accelerate config."
+        ),
+    )
+    parser.add_argument(
+        "--prior_generation_precision",
+        type=str,
+        default=None,
+        choices=["no", "fp32", "fp16", "bf16"],
+        help=(
+            "Choose prior generation precision between fp32, fp16 and bf16 (bfloat16). Bf16 requires PyTorch >="
+            " 1.10.and an Nvidia Ampere GPU.  Default to  fp16 if a GPU is available else fp32."
+        ),
+    )
+    parser.add_argument("--local_rank", type=int, default=-1, help="For distributed training: local_rank")
+    parser.add_argument(
+        "--enable_xformers_memory_efficient_attention", action="store_true", help="Whether or not to use xformers."
+    )
+    parser.add_argument(
+        "--rank",
+        type=int,
+        default=4,
+        help=("The dimension of the LoRA update matrices."),
+    )
+
+    if input_args is not None:
+        args = parser.parse_args(input_args)
+    else:
+        args = parser.parse_args()
+
+    if args.dataset_name is None and args.instance_data_dir is None:
+        raise ValueError("Specify either `--dataset_name` or `--instance_data_dir`")
+
+    if args.dataset_name is not None and args.instance_data_dir is not None:
+        raise ValueError("Specify only one of `--dataset_name` or `--instance_data_dir`")
+
+    env_local_rank = int(os.environ.get("LOCAL_RANK", -1))
+    if env_local_rank != -1 and env_local_rank != args.local_rank:
+        args.local_rank = env_local_rank
+
+    if args.with_prior_preservation:
+        if args.class_data_dir is None:
+            raise ValueError("You must specify a data directory for class images.")
+        if args.class_prompt is None:
+            raise ValueError("You must specify prompt for class images.")
+    else:
+        # logger is not available yet
+        if args.class_data_dir is not None:
+            warnings.warn("You need not use --class_data_dir without --with_prior_preservation.")
+        if args.class_prompt is not None:
+            warnings.warn("You need not use --class_prompt without --with_prior_preservation.")
+
+    return args
+
+
+class DreamBoothDataset(Dataset):
+    """
+    A dataset to prepare the instance and class images with the prompts for fine-tuning the model.
+    It pre-processes the images.
+    """
+
+    def __init__(
+        self,
+        instance_data_root,
+        instance_prompt,
+        class_prompt,
+        class_data_root=None,
+        class_num=None,
+        size=1024,
+        repeats=1,
+        center_crop=False,
+    ):
+        self.size = size
+        self.center_crop = center_crop
+
+        self.instance_prompt = instance_prompt
+        self.custom_instance_prompts = None
+        self.class_prompt = class_prompt
+
+        # if --dataset_name is provided or a metadata jsonl file is provided in the local --instance_data directory,
+        # we load the training data using load_dataset
+        if args.dataset_name is not None:
+            try:
+                from datasets import load_dataset
+            except ImportError:
+                raise ImportError(
+                    "You are trying to load your data using the datasets library. If you wish to train using custom "
+                    "captions please install the datasets library: `pip install datasets`. If you wish to load a "
+                    "local folder containing images only, specify --instance_data_dir instead."
+                )
+            # Downloading and loading a dataset from the hub.
+            # See more about loading custom images at
+            # https://huggingface.co/docs/datasets/v2.0.0/en/dataset_script
+            dataset = load_dataset(
+                args.dataset_name,
+                args.dataset_config_name,
+                cache_dir=args.cache_dir,
+            )
+            # Preprocessing the datasets.
+            column_names = dataset["train"].column_names
+
+            # 6. Get the column names for input/target.
+            if args.image_column is None:
+                image_column = column_names[0]
+                logger.info(f"image column defaulting to {image_column}")
+            else:
+                image_column = args.image_column
+                if image_column not in column_names:
+                    raise ValueError(
+                        f"`--image_column` value '{args.image_column}' not found in dataset columns. Dataset columns are: {', '.join(column_names)}"
+                    )
+            instance_images = dataset["train"][image_column]
+
+            if args.caption_column is None:
+                logger.info(
+                    "No caption column provided, defaulting to instance_prompt for all images. If your dataset "
+                    "contains captions/prompts for the images, make sure to specify the "
+                    "column as --caption_column"
+                )
+                self.custom_instance_prompts = None
+            else:
+                if args.caption_column not in column_names:
+                    raise ValueError(
+                        f"`--caption_column` value '{args.caption_column}' not found in dataset columns. Dataset columns are: {', '.join(column_names)}"
+                    )
+                custom_instance_prompts = dataset["train"][args.caption_column]
+                # create final list of captions according to --repeats
+                self.custom_instance_prompts = []
+                for caption in custom_instance_prompts:
+                    self.custom_instance_prompts.extend(itertools.repeat(caption, repeats))
+        else:
+            self.instance_data_root = Path(instance_data_root)
+            if not self.instance_data_root.exists():
+                raise ValueError("Instance images root doesn't exists.")
+
+            instance_images = [Image.open(path) for path in list(Path(instance_data_root).iterdir())]
+            self.custom_instance_prompts = None
+
+        self.instance_images = []
+        for img in instance_images:
+            self.instance_images.extend(itertools.repeat(img, repeats))
+        self.num_instance_images = len(self.instance_images)
+        self._length = self.num_instance_images
+
+        if class_data_root is not None:
+            self.class_data_root = Path(class_data_root)
+            self.class_data_root.mkdir(parents=True, exist_ok=True)
+            self.class_images_path = list(self.class_data_root.iterdir())
+            if class_num is not None:
+                self.num_class_images = min(len(self.class_images_path), class_num)
+            else:
+                self.num_class_images = len(self.class_images_path)
+            self._length = max(self.num_class_images, self.num_instance_images)
+        else:
+            self.class_data_root = None
+
+        self.image_transforms = transforms.Compose(
+            [
+                transforms.Resize(size, interpolation=transforms.InterpolationMode.BILINEAR),
+                transforms.CenterCrop(size) if center_crop else transforms.RandomCrop(size),
+                transforms.ToTensor(),
+                transforms.Normalize([0.5], [0.5]),
+            ]
+        )
+
+    def __len__(self):
+        return self._length
+
+    def __getitem__(self, index):
+        example = {}
+        instance_image = self.instance_images[index % self.num_instance_images]
+        instance_image = exif_transpose(instance_image)
+
+        if not instance_image.mode == "RGB":
+            instance_image = instance_image.convert("RGB")
+        example["instance_images"] = self.image_transforms(instance_image)
+
+        if self.custom_instance_prompts:
+            caption = self.custom_instance_prompts[index % self.num_instance_images]
+            if caption:
+                example["instance_prompt"] = caption
+            else:
+                example["instance_prompt"] = self.instance_prompt
+
+        else:  # costum prompts were provided, but length does not match size of image dataset
+            example["instance_prompt"] = self.instance_prompt
+
+        if self.class_data_root:
+            class_image = Image.open(self.class_images_path[index % self.num_class_images])
+            class_image = exif_transpose(class_image)
+
+            if not class_image.mode == "RGB":
+                class_image = class_image.convert("RGB")
+            example["class_images"] = self.image_transforms(class_image)
+            example["class_prompt"] = self.class_prompt
+
+        return example
+
+
+def collate_fn(examples, with_prior_preservation=False):
+    pixel_values = [example["instance_images"] for example in examples]
+    prompts = [example["instance_prompt"] for example in examples]
+
+    # Concat class and instance examples for prior preservation.
+    # We do this to avoid doing two forward passes.
+    if with_prior_preservation:
+        pixel_values += [example["class_images"] for example in examples]
+        prompts += [example["class_prompt"] for example in examples]
+
+    pixel_values = torch.stack(pixel_values)
+    pixel_values = pixel_values.to(memory_format=torch.contiguous_format).float()
+
+    batch = {"pixel_values": pixel_values, "prompts": prompts}
+    return batch
+
+
+class PromptDataset(Dataset):
+    "A simple dataset to prepare the prompts to generate class images on multiple GPUs."
+
+    def __init__(self, prompt, num_samples):
+        self.prompt = prompt
+        self.num_samples = num_samples
+
+    def __len__(self):
+        return self.num_samples
+
+    def __getitem__(self, index):
+        example = {}
+        example["prompt"] = self.prompt
+        example["index"] = index
+        return example
+
+
+def tokenize_prompt(tokenizer, prompt):
+    text_inputs = tokenizer(
+        prompt,
+        padding="max_length",
+        max_length=tokenizer.model_max_length,
+        truncation=True,
+        return_tensors="pt",
+    )
+    text_input_ids = text_inputs.input_ids
+    return text_input_ids
+
+
+# Adapted from pipelines.StableDiffusionXLPipeline.encode_prompt
+def encode_prompt(text_encoders, tokenizers, prompt, text_input_ids_list=None):
+    prompt_embeds_list = []
+
+    for i, text_encoder in enumerate(text_encoders):
+        if tokenizers is not None:
+            tokenizer = tokenizers[i]
+            text_input_ids = tokenize_prompt(tokenizer, prompt)
+        else:
+            assert text_input_ids_list is not None
+            text_input_ids = text_input_ids_list[i]
+
+        prompt_embeds = text_encoder(
+            text_input_ids.to(text_encoder.device),
+            output_hidden_states=True,
+        )
+
+        # We are only ALWAYS interested in the pooled output of the final text encoder
+        pooled_prompt_embeds = prompt_embeds[0]
+        prompt_embeds = prompt_embeds.hidden_states[-2]
+        bs_embed, seq_len, _ = prompt_embeds.shape
+        prompt_embeds = prompt_embeds.view(bs_embed, seq_len, -1)
+        prompt_embeds_list.append(prompt_embeds)
+
+    prompt_embeds = torch.concat(prompt_embeds_list, dim=-1)
+    pooled_prompt_embeds = pooled_prompt_embeds.view(bs_embed, -1)
+    return prompt_embeds, pooled_prompt_embeds
+
+
+def main(args):
+    logging_dir = Path(args.output_dir, args.logging_dir)
+
+    accelerator_project_config = ProjectConfiguration(project_dir=args.output_dir, logging_dir=logging_dir)
+    kwargs = DistributedDataParallelKwargs(find_unused_parameters=True)
+    accelerator = Accelerator(
+        gradient_accumulation_steps=args.gradient_accumulation_steps,
+        mixed_precision=args.mixed_precision,
+        log_with=args.report_to,
+        project_config=accelerator_project_config,
+        kwargs_handlers=[kwargs],
+    )
+
+    if args.report_to == "wandb":
+        if not is_wandb_available():
+            raise ImportError("Make sure to install wandb if you want to use it for logging during training.")
+        import wandb
+
+    # Make one log on every process with the configuration for debugging.
+    logging.basicConfig(
+        format="%(asctime)s - %(levelname)s - %(name)s - %(message)s",
+        datefmt="%m/%d/%Y %H:%M:%S",
+        level=logging.INFO,
+    )
+    logger.info(accelerator.state, main_process_only=False)
+    if accelerator.is_local_main_process:
+        transformers.utils.logging.set_verbosity_warning()
+        diffusers.utils.logging.set_verbosity_info()
+    else:
+        transformers.utils.logging.set_verbosity_error()
+        diffusers.utils.logging.set_verbosity_error()
+
+    # If passed along, set the training seed now.
+    if args.seed is not None:
+        set_seed(args.seed)
+
+    # Generate class images if prior preservation is enabled.
+    if args.with_prior_preservation:
+        class_images_dir = Path(args.class_data_dir)
+        if not class_images_dir.exists():
+            class_images_dir.mkdir(parents=True)
+        cur_class_images = len(list(class_images_dir.iterdir()))
+
+        if cur_class_images < args.num_class_images:
+            torch_dtype = torch.float16 if accelerator.device.type == "cuda" else torch.float32
+            if args.prior_generation_precision == "fp32":
+                torch_dtype = torch.float32
+            elif args.prior_generation_precision == "fp16":
+                torch_dtype = torch.float16
+            elif args.prior_generation_precision == "bf16":
+                torch_dtype = torch.bfloat16
+            pipeline = StableDiffusionXLPipeline.from_pretrained(
+                args.pretrained_model_name_or_path,
+                torch_dtype=torch_dtype,
+                revision=args.revision,
+                variant=args.variant,
+            )
+            pipeline.set_progress_bar_config(disable=True)
+
+            num_new_images = args.num_class_images - cur_class_images
+            logger.info(f"Number of class images to sample: {num_new_images}.")
+
+            sample_dataset = PromptDataset(args.class_prompt, num_new_images)
+            sample_dataloader = torch.utils.data.DataLoader(sample_dataset, batch_size=args.sample_batch_size)
+
+            sample_dataloader = accelerator.prepare(sample_dataloader)
+            pipeline.to(accelerator.device)
+
+            for example in tqdm(
+                sample_dataloader, desc="Generating class images", disable=not accelerator.is_local_main_process
+            ):
+                images = pipeline(example["prompt"]).images
+
+                for i, image in enumerate(images):
+                    hash_image = insecure_hashlib.sha1(image.tobytes()).hexdigest()
+                    image_filename = class_images_dir / f"{example['index'][i] + cur_class_images}-{hash_image}.jpg"
+                    image.save(image_filename)
+
+            del pipeline
+            if torch.cuda.is_available():
+                torch.cuda.empty_cache()
+
+    # Handle the repository creation
+    if accelerator.is_main_process:
+        if args.output_dir is not None:
+            os.makedirs(args.output_dir, exist_ok=True)
+
+        if args.push_to_hub:
+            repo_id = create_repo(
+                repo_id=args.hub_model_id or Path(args.output_dir).name, exist_ok=True, token=args.hub_token
+            ).repo_id
+
+    # Load the tokenizers
+    tokenizer_one = AutoTokenizer.from_pretrained(
+        args.pretrained_model_name_or_path,
+        subfolder="tokenizer",
+        revision=args.revision,
+        use_fast=False,
+    )
+    tokenizer_two = AutoTokenizer.from_pretrained(
+        args.pretrained_model_name_or_path,
+        subfolder="tokenizer_2",
+        revision=args.revision,
+        use_fast=False,
+    )
+
+    # import correct text encoder classes
+    text_encoder_cls_one = import_model_class_from_model_name_or_path(
+        args.pretrained_model_name_or_path, args.revision
+    )
+    text_encoder_cls_two = import_model_class_from_model_name_or_path(
+        args.pretrained_model_name_or_path, args.revision, subfolder="text_encoder_2"
+    )
+
+    # Load scheduler and models
+    noise_scheduler = DDPMScheduler.from_pretrained(args.pretrained_model_name_or_path, subfolder="scheduler")
+    text_encoder_one = text_encoder_cls_one.from_pretrained(
+        args.pretrained_model_name_or_path, subfolder="text_encoder", revision=args.revision, variant=args.variant
+    )
+    text_encoder_two = text_encoder_cls_two.from_pretrained(
+        args.pretrained_model_name_or_path, subfolder="text_encoder_2", revision=args.revision, variant=args.variant
+    )
+    vae_path = (
+        args.pretrained_model_name_or_path
+        if args.pretrained_vae_model_name_or_path is None
+        else args.pretrained_vae_model_name_or_path
+    )
+    vae = AutoencoderKL.from_pretrained(
+        vae_path,
+        subfolder="vae" if args.pretrained_vae_model_name_or_path is None else None,
+        revision=args.revision,
+        variant=args.variant,
+    )
+    unet = UNet2DConditionModel.from_pretrained(
+        args.pretrained_model_name_or_path, subfolder="unet", revision=args.revision, variant=args.variant
+    )
+
+    # We only train the additional adapter LoRA layers
+    vae.requires_grad_(False)
+    text_encoder_one.requires_grad_(False)
+    text_encoder_two.requires_grad_(False)
+    unet.requires_grad_(False)
+
+    # For mixed precision training we cast all non-trainable weights (vae, non-lora text_encoder and non-lora unet) to half-precision
+    # as these weights are only used for inference, keeping weights in full precision is not required.
+    weight_dtype = torch.float32
+    if accelerator.mixed_precision == "fp16":
+        weight_dtype = torch.float16
+    elif accelerator.mixed_precision == "bf16":
+        weight_dtype = torch.bfloat16
+
+    # Move unet, vae and text_encoder to device and cast to weight_dtype
+    unet.to(accelerator.device, dtype=weight_dtype)
+
+    # The VAE is always in float32 to avoid NaN losses.
+    vae.to(accelerator.device, dtype=torch.float32)
+
+    text_encoder_one.to(accelerator.device, dtype=weight_dtype)
+    text_encoder_two.to(accelerator.device, dtype=weight_dtype)
+
+    if args.enable_xformers_memory_efficient_attention:
+        if is_xformers_available():
+            import xformers
+
+            xformers_version = version.parse(xformers.__version__)
+            if xformers_version == version.parse("0.0.16"):
+                logger.warn(
+                    "xFormers 0.0.16 cannot be used for training in some GPUs. If you observe problems during training, "
+                    "please update xFormers to at least 0.0.17. See https://huggingface.co/docs/diffusers/main/en/optimization/xformers for more details."
+                )
+            unet.enable_xformers_memory_efficient_attention()
+        else:
+            raise ValueError("xformers is not available. Make sure it is installed correctly")
+
+    if args.gradient_checkpointing:
+        unet.enable_gradient_checkpointing()
+        if args.train_text_encoder:
+            text_encoder_one.gradient_checkpointing_enable()
+            text_encoder_two.gradient_checkpointing_enable()
+
+    # now we will add new LoRA weights to the attention layers
+    unet_lora_config = LoraConfig(
+        r=args.rank,
+        lora_alpha=args.rank,
+        init_lora_weights="gaussian",
+        target_modules=["to_k", "to_q", "to_v", "to_out.0"],
+    )
+    unet.add_adapter(unet_lora_config)
+
+    # The text encoder comes from 🤗 transformers, so we cannot directly modify it.
+    # So, instead, we monkey-patch the forward calls of its attention-blocks.
+    if args.train_text_encoder:
+        text_lora_config = LoraConfig(
+            r=args.rank,
+            lora_alpha=args.rank,
+            init_lora_weights="gaussian",
+            target_modules=["q_proj", "k_proj", "v_proj", "out_proj"],
+        )
+        text_encoder_one.add_adapter(text_lora_config)
+        text_encoder_two.add_adapter(text_lora_config)
+
+    # Make sure the trainable params are in float32.
+    if args.mixed_precision == "fp16":
+        models = [unet]
+        if args.train_text_encoder:
+            models.extend([text_encoder_one, text_encoder_two])
+        for model in models:
+            for param in model.parameters():
+                # only upcast trainable parameters (LoRA) into fp32
+                if param.requires_grad:
+                    param.data = param.to(torch.float32)
+
+    # create custom saving & loading hooks so that `accelerator.save_state(...)` serializes in a nice format
+    def save_model_hook(models, weights, output_dir):
+        if accelerator.is_main_process:
+            # there are only two options here. Either are just the unet attn processor layers
+            # or there are the unet and text encoder atten layers
+            unet_lora_layers_to_save = None
+            text_encoder_one_lora_layers_to_save = None
+            text_encoder_two_lora_layers_to_save = None
+
+            for model in models:
+                if isinstance(model, type(accelerator.unwrap_model(unet))):
+                    unet_lora_layers_to_save = get_peft_model_state_dict(model)
+                elif isinstance(model, type(accelerator.unwrap_model(text_encoder_one))):
+                    text_encoder_one_lora_layers_to_save = get_peft_model_state_dict(model)
+                elif isinstance(model, type(accelerator.unwrap_model(text_encoder_two))):
+                    text_encoder_two_lora_layers_to_save = get_peft_model_state_dict(model)
+                else:
+                    raise ValueError(f"unexpected save model: {model.__class__}")
+
+                # make sure to pop weight so that corresponding model is not saved again
+                weights.pop()
+
+            StableDiffusionXLPipeline.save_lora_weights(
+                output_dir,
+                unet_lora_layers=unet_lora_layers_to_save,
+                text_encoder_lora_layers=text_encoder_one_lora_layers_to_save,
+                text_encoder_2_lora_layers=text_encoder_two_lora_layers_to_save,
+            )
+
+    def load_model_hook(models, input_dir):
+        unet_ = None
+        text_encoder_one_ = None
+        text_encoder_two_ = None
+
+        while len(models) > 0:
+            model = models.pop()
+
+            if isinstance(model, type(accelerator.unwrap_model(unet))):
+                unet_ = model
+            elif isinstance(model, type(accelerator.unwrap_model(text_encoder_one))):
+                text_encoder_one_ = model
+            elif isinstance(model, type(accelerator.unwrap_model(text_encoder_two))):
+                text_encoder_two_ = model
+            else:
+                raise ValueError(f"unexpected save model: {model.__class__}")
+
+        lora_state_dict, network_alphas = LoraLoaderMixin.lora_state_dict(input_dir)
+        LoraLoaderMixin.load_lora_into_unet(lora_state_dict, network_alphas=network_alphas, unet=unet_)
+
+        text_encoder_state_dict = {k: v for k, v in lora_state_dict.items() if "text_encoder." in k}
+        LoraLoaderMixin.load_lora_into_text_encoder(
+            text_encoder_state_dict, network_alphas=network_alphas, text_encoder=text_encoder_one_
+        )
+
+        text_encoder_2_state_dict = {k: v for k, v in lora_state_dict.items() if "text_encoder_2." in k}
+        LoraLoaderMixin.load_lora_into_text_encoder(
+            text_encoder_2_state_dict, network_alphas=network_alphas, text_encoder=text_encoder_two_
+        )
+
+    accelerator.register_save_state_pre_hook(save_model_hook)
+    accelerator.register_load_state_pre_hook(load_model_hook)
+
+    # Enable TF32 for faster training on Ampere GPUs,
+    # cf https://pytorch.org/docs/stable/notes/cuda.html#tensorfloat-32-tf32-on-ampere-devices
+    if args.allow_tf32:
+        torch.backends.cuda.matmul.allow_tf32 = True
+
+    if args.scale_lr:
+        args.learning_rate = (
+            args.learning_rate * args.gradient_accumulation_steps * args.train_batch_size * accelerator.num_processes
+        )
+
+    unet_lora_parameters = list(filter(lambda p: p.requires_grad, unet.parameters()))
+
+    if args.train_text_encoder:
+        text_lora_parameters_one = list(filter(lambda p: p.requires_grad, text_encoder_one.parameters()))
+        text_lora_parameters_two = list(filter(lambda p: p.requires_grad, text_encoder_two.parameters()))
+
+    # Optimization parameters
+    unet_lora_parameters_with_lr = {"params": unet_lora_parameters, "lr": args.learning_rate}
+    if args.train_text_encoder:
+        # different learning rate for text encoder and unet
+        text_lora_parameters_one_with_lr = {
+            "params": text_lora_parameters_one,
+            "weight_decay": args.adam_weight_decay_text_encoder,
+            "lr": args.text_encoder_lr if args.text_encoder_lr else args.learning_rate,
+        }
+        text_lora_parameters_two_with_lr = {
+            "params": text_lora_parameters_two,
+            "weight_decay": args.adam_weight_decay_text_encoder,
+            "lr": args.text_encoder_lr if args.text_encoder_lr else args.learning_rate,
+        }
+        params_to_optimize = [
+            unet_lora_parameters_with_lr,
+            text_lora_parameters_one_with_lr,
+            text_lora_parameters_two_with_lr,
+        ]
+    else:
+        params_to_optimize = [unet_lora_parameters_with_lr]
+
+    # Optimizer creation
+    if not (args.optimizer.lower() == "prodigy" or args.optimizer.lower() == "adamw"):
+        logger.warn(
+            f"Unsupported choice of optimizer: {args.optimizer}.Supported optimizers include [adamW, prodigy]."
+            "Defaulting to adamW"
+        )
+        args.optimizer = "adamw"
+
+    if args.use_8bit_adam and not args.optimizer.lower() == "adamw":
+        logger.warn(
+            f"use_8bit_adam is ignored when optimizer is not set to 'AdamW'. Optimizer was "
+            f"set to {args.optimizer.lower()}"
+        )
+
+    if args.optimizer.lower() == "adamw":
+        if args.use_8bit_adam:
+            try:
+                import bitsandbytes as bnb
+            except ImportError:
+                raise ImportError(
+                    "To use 8-bit Adam, please install the bitsandbytes library: `pip install bitsandbytes`."
+                )
+
+            optimizer_class = bnb.optim.AdamW8bit
+        else:
+            optimizer_class = torch.optim.AdamW
+
+        optimizer = optimizer_class(
+            params_to_optimize,
+            betas=(args.adam_beta1, args.adam_beta2),
+            weight_decay=args.adam_weight_decay,
+            eps=args.adam_epsilon,
+        )
+
+    if args.optimizer.lower() == "prodigy":
+        try:
+            import prodigyopt
+        except ImportError:
+            raise ImportError("To use Prodigy, please install the prodigyopt library: `pip install prodigyopt`")
+
+        optimizer_class = prodigyopt.Prodigy
+
+        optimizer = optimizer_class(
+            params_to_optimize,
+            lr=args.learning_rate,
+            betas=(args.adam_beta1, args.adam_beta2),
+            weight_decay=args.adam_weight_decay,
+            eps=args.adam_epsilon,
+            decouple=args.prodigy_decouple,
+            use_bias_correction=args.prodigy_use_bias_correction,
+            safeguard_warmup=args.prodigy_safeguard_warmup,
+        )
+
+    # Dataset and DataLoaders creation:
+    train_dataset = DreamBoothDataset(
+        instance_data_root=args.instance_data_dir,
+        instance_prompt=args.instance_prompt,
+        class_prompt=args.class_prompt,
+        class_data_root=args.class_data_dir if args.with_prior_preservation else None,
+        class_num=args.num_class_images,
+        size=args.resolution,
+        repeats=args.repeats,
+        center_crop=args.center_crop,
+    )
+
+    train_dataloader = torch.utils.data.DataLoader(
+        train_dataset,
+        batch_size=args.train_batch_size,
+        shuffle=True,
+        collate_fn=lambda examples: collate_fn(examples, args.with_prior_preservation),
+        num_workers=args.dataloader_num_workers,
+    )
+
+    # Computes additional embeddings/ids required by the SDXL UNet.
+    # regular text embeddings (when `train_text_encoder` is not True)
+    # pooled text embeddings
+    # time ids
+
+    def compute_time_ids():
+        # Adapted from pipeline.StableDiffusionXLPipeline._get_add_time_ids
+        original_size = (args.resolution, args.resolution)
+        target_size = (args.resolution, args.resolution)
+        crops_coords_top_left = (args.crops_coords_top_left_h, args.crops_coords_top_left_w)
+        add_time_ids = list(original_size + crops_coords_top_left + target_size)
+        add_time_ids = torch.tensor([add_time_ids])
+        add_time_ids = add_time_ids.to(accelerator.device, dtype=weight_dtype)
+        return add_time_ids
+
+    if not args.train_text_encoder:
+        tokenizers = [tokenizer_one, tokenizer_two]
+        text_encoders = [text_encoder_one, text_encoder_two]
+
+        def compute_text_embeddings(prompt, text_encoders, tokenizers):
+            with torch.no_grad():
+                prompt_embeds, pooled_prompt_embeds = encode_prompt(text_encoders, tokenizers, prompt)
+                prompt_embeds = prompt_embeds.to(accelerator.device)
+                pooled_prompt_embeds = pooled_prompt_embeds.to(accelerator.device)
+            return prompt_embeds, pooled_prompt_embeds
+
+    # Handle instance prompt.
+    instance_time_ids = compute_time_ids()
+
+    # If no type of tuning is done on the text_encoder and custom instance prompts are NOT
+    # provided (i.e. the --instance_prompt is used for all images), we encode the instance prompt once to avoid
+    # the redundant encoding.
+    if not args.train_text_encoder and not train_dataset.custom_instance_prompts:
+        instance_prompt_hidden_states, instance_pooled_prompt_embeds = compute_text_embeddings(
+            args.instance_prompt, text_encoders, tokenizers
+        )
+
+    # Handle class prompt for prior-preservation.
+    if args.with_prior_preservation:
+        class_time_ids = compute_time_ids()
+        if not args.train_text_encoder:
+            class_prompt_hidden_states, class_pooled_prompt_embeds = compute_text_embeddings(
+                args.class_prompt, text_encoders, tokenizers
+            )
+
+    # Clear the memory here
+    if not args.train_text_encoder and not train_dataset.custom_instance_prompts:
+        del tokenizers, text_encoders
+        gc.collect()
+        torch.cuda.empty_cache()
+
+    # If custom instance prompts are NOT provided (i.e. the instance prompt is used for all images),
+    # pack the statically computed variables appropriately here. This is so that we don't
+    # have to pass them to the dataloader.
+    add_time_ids = instance_time_ids
+    if args.with_prior_preservation:
+        add_time_ids = torch.cat([add_time_ids, class_time_ids], dim=0)
+
+    if not train_dataset.custom_instance_prompts:
+        if not args.train_text_encoder:
+            prompt_embeds = instance_prompt_hidden_states
+            unet_add_text_embeds = instance_pooled_prompt_embeds
+            if args.with_prior_preservation:
+                prompt_embeds = torch.cat([prompt_embeds, class_prompt_hidden_states], dim=0)
+                unet_add_text_embeds = torch.cat([unet_add_text_embeds, class_pooled_prompt_embeds], dim=0)
+        # if we're optmizing the text encoder (both if instance prompt is used for all images or custom prompts) we need to tokenize and encode the
+        # batch prompts on all training steps
+        else:
+            tokens_one = tokenize_prompt(tokenizer_one, args.instance_prompt)
+            tokens_two = tokenize_prompt(tokenizer_two, args.instance_prompt)
+            if args.with_prior_preservation:
+                class_tokens_one = tokenize_prompt(tokenizer_one, args.class_prompt)
+                class_tokens_two = tokenize_prompt(tokenizer_two, args.class_prompt)
+                tokens_one = torch.cat([tokens_one, class_tokens_one], dim=0)
+                tokens_two = torch.cat([tokens_two, class_tokens_two], dim=0)
+
+    # Scheduler and math around the number of training steps.
+    overrode_max_train_steps = False
+    num_update_steps_per_epoch = math.ceil(len(train_dataloader) / args.gradient_accumulation_steps)
+    if args.max_train_steps is None:
+        args.max_train_steps = args.num_train_epochs * num_update_steps_per_epoch
+        overrode_max_train_steps = True
+
+    lr_scheduler = get_scheduler(
+        args.lr_scheduler,
+        optimizer=optimizer,
+        num_warmup_steps=args.lr_warmup_steps * accelerator.num_processes,
+        num_training_steps=args.max_train_steps * accelerator.num_processes,
+        num_cycles=args.lr_num_cycles,
+        power=args.lr_power,
+    )
+
+    # Prepare everything with our `accelerator`.
+    if args.train_text_encoder:
+        unet, text_encoder_one, text_encoder_two, optimizer, train_dataloader, lr_scheduler = accelerator.prepare(
+            unet, text_encoder_one, text_encoder_two, optimizer, train_dataloader, lr_scheduler
+        )
+    else:
+        unet, optimizer, train_dataloader, lr_scheduler = accelerator.prepare(
+            unet, optimizer, train_dataloader, lr_scheduler
+        )
+
+    # We need to recalculate our total training steps as the size of the training dataloader may have changed.
+    num_update_steps_per_epoch = math.ceil(len(train_dataloader) / args.gradient_accumulation_steps)
+    if overrode_max_train_steps:
+        args.max_train_steps = args.num_train_epochs * num_update_steps_per_epoch
+    # Afterwards we recalculate our number of training epochs
+    args.num_train_epochs = math.ceil(args.max_train_steps / num_update_steps_per_epoch)
+
+    # We need to initialize the trackers we use, and also store our configuration.
+    # The trackers initializes automatically on the main process.
+    if accelerator.is_main_process:
+        accelerator.init_trackers("dreambooth-lora-sd-xl", config=vars(args))
+
+    # Train!
+    total_batch_size = args.train_batch_size * accelerator.num_processes * args.gradient_accumulation_steps
+
+    logger.info("***** Running training *****")
+    logger.info(f"  Num examples = {len(train_dataset)}")
+    logger.info(f"  Num batches each epoch = {len(train_dataloader)}")
+    logger.info(f"  Num Epochs = {args.num_train_epochs}")
+    logger.info(f"  Instantaneous batch size per device = {args.train_batch_size}")
+    logger.info(f"  Total train batch size (w. parallel, distributed & accumulation) = {total_batch_size}")
+    logger.info(f"  Gradient Accumulation steps = {args.gradient_accumulation_steps}")
+    logger.info(f"  Total optimization steps = {args.max_train_steps}")
+    global_step = 0
+    first_epoch = 0
+
+    # Potentially load in the weights and states from a previous save
+    if args.resume_from_checkpoint:
+        if args.resume_from_checkpoint != "latest":
+            path = os.path.basename(args.resume_from_checkpoint)
+        else:
+            # Get the mos recent checkpoint
+            dirs = os.listdir(args.output_dir)
+            dirs = [d for d in dirs if d.startswith("checkpoint")]
+            dirs = sorted(dirs, key=lambda x: int(x.split("-")[1]))
+            path = dirs[-1] if len(dirs) > 0 else None
+
+        if path is None:
+            accelerator.print(
+                f"Checkpoint '{args.resume_from_checkpoint}' does not exist. Starting a new training run."
+            )
+            args.resume_from_checkpoint = None
+            initial_global_step = 0
+        else:
+            accelerator.print(f"Resuming from checkpoint {path}")
+            accelerator.load_state(os.path.join(args.output_dir, path))
+            global_step = int(path.split("-")[1])
+
+            initial_global_step = global_step
+            first_epoch = global_step // num_update_steps_per_epoch
+
+    else:
+        initial_global_step = 0
+
+    progress_bar = tqdm(
+        range(0, args.max_train_steps),
+        initial=initial_global_step,
+        desc="Steps",
+        # Only show the progress bar once on each machine.
+        disable=not accelerator.is_local_main_process,
+    )
+
+    for epoch in range(first_epoch, args.num_train_epochs):
+        unet.train()
+        if args.train_text_encoder:
+            text_encoder_one.train()
+            text_encoder_two.train()
+
+            # set top parameter requires_grad = True for gradient checkpointing works
+            text_encoder_one.text_model.embeddings.requires_grad_(True)
+            text_encoder_two.text_model.embeddings.requires_grad_(True)
+
+        for step, batch in enumerate(train_dataloader):
+            with accelerator.accumulate(unet):
+                pixel_values = batch["pixel_values"].to(dtype=vae.dtype)
+                prompts = batch["prompts"]
+
+                # encode batch prompts when custom prompts are provided for each image -
+                if train_dataset.custom_instance_prompts:
+                    if not args.train_text_encoder:
+                        prompt_embeds, unet_add_text_embeds = compute_text_embeddings(
+                            prompts, text_encoders, tokenizers
+                        )
+                    else:
+                        tokens_one = tokenize_prompt(tokenizer_one, prompts)
+                        tokens_two = tokenize_prompt(tokenizer_two, prompts)
+
+                # Convert images to latent space
+                model_input = vae.encode(pixel_values).latent_dist.sample()
+                model_input = model_input * vae.config.scaling_factor
+                if args.pretrained_vae_model_name_or_path is None:
+                    model_input = model_input.to(weight_dtype)
+
+                # Sample noise that we'll add to the latents
+                noise = torch.randn_like(model_input)
+                bsz = model_input.shape[0]
+                # Sample a random timestep for each image
+                timesteps = torch.randint(
+                    0, noise_scheduler.config.num_train_timesteps, (bsz,), device=model_input.device
+                )
+                timesteps = timesteps.long()
+
+                # Add noise to the model input according to the noise magnitude at each timestep
+                # (this is the forward diffusion process)
+                noisy_model_input = noise_scheduler.add_noise(model_input, noise, timesteps)
+
+                # Calculate the elements to repeat depending on the use of prior-preservation and custom captions.
+                if not train_dataset.custom_instance_prompts:
+                    elems_to_repeat_text_embeds = bsz // 2 if args.with_prior_preservation else bsz
+                    elems_to_repeat_time_ids = bsz // 2 if args.with_prior_preservation else bsz
+                else:
+                    elems_to_repeat_text_embeds = 1
+                    elems_to_repeat_time_ids = bsz // 2 if args.with_prior_preservation else bsz
+
+                # Predict the noise residual
+                if not args.train_text_encoder:
+                    unet_added_conditions = {
+                        "time_ids": add_time_ids.repeat(elems_to_repeat_time_ids, 1),
+                        "text_embeds": unet_add_text_embeds.repeat(elems_to_repeat_text_embeds, 1),
+                    }
+                    prompt_embeds_input = prompt_embeds.repeat(elems_to_repeat_text_embeds, 1, 1)
+                    model_pred = unet(
+                        noisy_model_input,
+                        timesteps,
+                        prompt_embeds_input,
+                        added_cond_kwargs=unet_added_conditions,
+                    ).sample
+                else:
+                    unet_added_conditions = {"time_ids": add_time_ids.repeat(elems_to_repeat_time_ids, 1)}
+                    prompt_embeds, pooled_prompt_embeds = encode_prompt(
+                        text_encoders=[text_encoder_one, text_encoder_two],
+                        tokenizers=None,
+                        prompt=None,
+                        text_input_ids_list=[tokens_one, tokens_two],
+                    )
+                    unet_added_conditions.update(
+                        {"text_embeds": pooled_prompt_embeds.repeat(elems_to_repeat_text_embeds, 1)}
+                    )
+                    prompt_embeds_input = prompt_embeds.repeat(elems_to_repeat_text_embeds, 1, 1)
+                    model_pred = unet(
+                        noisy_model_input, timesteps, prompt_embeds_input, added_cond_kwargs=unet_added_conditions
+                    ).sample
+
+                # Get the target for loss depending on the prediction type
+                if noise_scheduler.config.prediction_type == "epsilon":
+                    target = noise
+                elif noise_scheduler.config.prediction_type == "v_prediction":
+                    target = noise_scheduler.get_velocity(model_input, noise, timesteps)
+                else:
+                    raise ValueError(f"Unknown prediction type {noise_scheduler.config.prediction_type}")
+
+                if args.with_prior_preservation:
+                    # Chunk the noise and model_pred into two parts and compute the loss on each part separately.
+                    model_pred, model_pred_prior = torch.chunk(model_pred, 2, dim=0)
+                    target, target_prior = torch.chunk(target, 2, dim=0)
+
+                    # Compute prior loss
+                    prior_loss = F.mse_loss(model_pred_prior.float(), target_prior.float(), reduction="mean")
+
+                if args.snr_gamma is None:
+                    loss = F.mse_loss(model_pred.float(), target.float(), reduction="mean")
+                else:
+                    # Compute loss-weights as per Section 3.4 of https://arxiv.org/abs/2303.09556.
+                    # Since we predict the noise instead of x_0, the original formulation is slightly changed.
+                    # This is discussed in Section 4.2 of the same paper.
+                    snr = compute_snr(noise_scheduler, timesteps)
+                    base_weight = (
+                        torch.stack([snr, args.snr_gamma * torch.ones_like(timesteps)], dim=1).min(dim=1)[0] / snr
+                    )
+
+                    if noise_scheduler.config.prediction_type == "v_prediction":
+                        # Velocity objective needs to be floored to an SNR weight of one.
+                        mse_loss_weights = base_weight + 1
+                    else:
+                        # Epsilon and sample both use the same loss weights.
+                        mse_loss_weights = base_weight
+
+                    loss = F.mse_loss(model_pred.float(), target.float(), reduction="none")
+                    loss = loss.mean(dim=list(range(1, len(loss.shape)))) * mse_loss_weights
+                    loss = loss.mean()
+
+                if args.with_prior_preservation:
+                    # Add the prior loss to the instance loss.
+                    loss = loss + args.prior_loss_weight * prior_loss
+
+                accelerator.backward(loss)
+                if accelerator.sync_gradients:
+                    params_to_clip = (
+                        itertools.chain(unet_lora_parameters, text_lora_parameters_one, text_lora_parameters_two)
+                        if args.train_text_encoder
+                        else unet_lora_parameters
+                    )
+                    accelerator.clip_grad_norm_(params_to_clip, args.max_grad_norm)
+                optimizer.step()
+                lr_scheduler.step()
+                optimizer.zero_grad()
+
+            # Checks if the accelerator has performed an optimization step behind the scenes
+            if accelerator.sync_gradients:
+                progress_bar.update(1)
+                global_step += 1
+
+                if accelerator.is_main_process:
+                    if global_step % args.checkpointing_steps == 0:
+                        # _before_ saving state, check if this save would set us over the `checkpoints_total_limit`
+                        if args.checkpoints_total_limit is not None:
+                            checkpoints = os.listdir(args.output_dir)
+                            checkpoints = [d for d in checkpoints if d.startswith("checkpoint")]
+                            checkpoints = sorted(checkpoints, key=lambda x: int(x.split("-")[1]))
+
+                            # before we save the new checkpoint, we need to have at _most_ `checkpoints_total_limit - 1` checkpoints
+                            if len(checkpoints) >= args.checkpoints_total_limit:
+                                num_to_remove = len(checkpoints) - args.checkpoints_total_limit + 1
+                                removing_checkpoints = checkpoints[0:num_to_remove]
+
+                                logger.info(
+                                    f"{len(checkpoints)} checkpoints already exist, removing {len(removing_checkpoints)} checkpoints"
+                                )
+                                logger.info(f"removing checkpoints: {', '.join(removing_checkpoints)}")
+
+                                for removing_checkpoint in removing_checkpoints:
+                                    removing_checkpoint = os.path.join(args.output_dir, removing_checkpoint)
+                                    shutil.rmtree(removing_checkpoint)
+
+                        save_path = os.path.join(args.output_dir, f"checkpoint-{global_step}")
+                        accelerator.save_state(save_path)
+                        logger.info(f"Saved state to {save_path}")
+
+            logs = {"loss": loss.detach().item(), "lr": lr_scheduler.get_last_lr()[0]}
+            progress_bar.set_postfix(**logs)
+            accelerator.log(logs, step=global_step)
+
+            if global_step >= args.max_train_steps:
+                break
+
+        if accelerator.is_main_process:
+            if args.validation_prompt is not None and epoch % args.validation_epochs == 0:
+                logger.info(
+                    f"Running validation... \n Generating {args.num_validation_images} images with prompt:"
+                    f" {args.validation_prompt}."
+                )
+                # create pipeline
+                if not args.train_text_encoder:
+                    text_encoder_one = text_encoder_cls_one.from_pretrained(
+                        args.pretrained_model_name_or_path,
+                        subfolder="text_encoder",
+                        revision=args.revision,
+                        variant=args.variant,
+                    )
+                    text_encoder_two = text_encoder_cls_two.from_pretrained(
+                        args.pretrained_model_name_or_path,
+                        subfolder="text_encoder_2",
+                        revision=args.revision,
+                        variant=args.variant,
+                    )
+                pipeline = StableDiffusionXLPipeline.from_pretrained(
+                    args.pretrained_model_name_or_path,
+                    vae=vae,
+                    text_encoder=accelerator.unwrap_model(text_encoder_one),
+                    text_encoder_2=accelerator.unwrap_model(text_encoder_two),
+                    unet=accelerator.unwrap_model(unet),
+                    revision=args.revision,
+                    variant=args.variant,
+                    torch_dtype=weight_dtype,
+                )
+
+                # We train on the simplified learning objective. If we were previously predicting a variance, we need the scheduler to ignore it
+                scheduler_args = {}
+
+                if "variance_type" in pipeline.scheduler.config:
+                    variance_type = pipeline.scheduler.config.variance_type
+
+                    if variance_type in ["learned", "learned_range"]:
+                        variance_type = "fixed_small"
+
+                    scheduler_args["variance_type"] = variance_type
+
+                pipeline.scheduler = DPMSolverMultistepScheduler.from_config(
+                    pipeline.scheduler.config, **scheduler_args
+                )
+
+                pipeline = pipeline.to(accelerator.device)
+                pipeline.set_progress_bar_config(disable=True)
+
+                # run inference
+                generator = torch.Generator(device=accelerator.device).manual_seed(args.seed) if args.seed else None
+                pipeline_args = {"prompt": args.validation_prompt}
+
+                with torch.cuda.amp.autocast():
+                    images = [
+                        pipeline(**pipeline_args, generator=generator).images[0]
+                        for _ in range(args.num_validation_images)
+                    ]
+
+                for tracker in accelerator.trackers:
+                    if tracker.name == "tensorboard":
+                        np_images = np.stack([np.asarray(img) for img in images])
+                        tracker.writer.add_images("validation", np_images, epoch, dataformats="NHWC")
+                    if tracker.name == "wandb":
+                        tracker.log(
+                            {
+                                "validation": [
+                                    wandb.Image(image, caption=f"{i}: {args.validation_prompt}")
+                                    for i, image in enumerate(images)
+                                ]
+                            }
+                        )
+
+                del pipeline
+                torch.cuda.empty_cache()
+
+    # Save the lora layers
+    accelerator.wait_for_everyone()
+    if accelerator.is_main_process:
+        unet = accelerator.unwrap_model(unet)
+        unet = unet.to(torch.float32)
+        unet_lora_layers = get_peft_model_state_dict(unet)
+
+        if args.train_text_encoder:
+            text_encoder_one = accelerator.unwrap_model(text_encoder_one)
+            text_encoder_lora_layers = get_peft_model_state_dict(text_encoder_one.to(torch.float32))
+            text_encoder_two = accelerator.unwrap_model(text_encoder_two)
+            text_encoder_2_lora_layers = get_peft_model_state_dict(text_encoder_two.to(torch.float32))
+        else:
+            text_encoder_lora_layers = None
+            text_encoder_2_lora_layers = None
+
+        StableDiffusionXLPipeline.save_lora_weights(
+            save_directory=args.output_dir,
+            unet_lora_layers=unet_lora_layers,
+            text_encoder_lora_layers=text_encoder_lora_layers,
+            text_encoder_2_lora_layers=text_encoder_2_lora_layers,
+        )
+
+        # Final inference
+        # Load previous pipeline
+        vae = AutoencoderKL.from_pretrained(
+            vae_path,
+            subfolder="vae" if args.pretrained_vae_model_name_or_path is None else None,
+            revision=args.revision,
+            variant=args.variant,
+            torch_dtype=weight_dtype,
+        )
+        pipeline = StableDiffusionXLPipeline.from_pretrained(
+            args.pretrained_model_name_or_path,
+            vae=vae,
+            revision=args.revision,
+            variant=args.variant,
+            torch_dtype=weight_dtype,
+        )
+
+        # We train on the simplified learning objective. If we were previously predicting a variance, we need the scheduler to ignore it
+        scheduler_args = {}
+
+        if "variance_type" in pipeline.scheduler.config:
+            variance_type = pipeline.scheduler.config.variance_type
+
+            if variance_type in ["learned", "learned_range"]:
+                variance_type = "fixed_small"
+
+            scheduler_args["variance_type"] = variance_type
+
+        pipeline.scheduler = DPMSolverMultistepScheduler.from_config(pipeline.scheduler.config, **scheduler_args)
+
+        # load attention processors
+        pipeline.load_lora_weights(args.output_dir)
+
+        # run inference
+        images = []
+        if args.validation_prompt and args.num_validation_images > 0:
+            pipeline = pipeline.to(accelerator.device)
+            generator = torch.Generator(device=accelerator.device).manual_seed(args.seed) if args.seed else None
+            images = [
+                pipeline(args.validation_prompt, num_inference_steps=25, generator=generator).images[0]
+                for _ in range(args.num_validation_images)
+            ]
+
+            for tracker in accelerator.trackers:
+                if tracker.name == "tensorboard":
+                    np_images = np.stack([np.asarray(img) for img in images])
+                    tracker.writer.add_images("test", np_images, epoch, dataformats="NHWC")
+                if tracker.name == "wandb":
+                    tracker.log(
+                        {
+                            "test": [
+                                wandb.Image(image, caption=f"{i}: {args.validation_prompt}")
+                                for i, image in enumerate(images)
+                            ]
+                        }
+                    )
+
+        if args.push_to_hub:
+            save_model_card(
+                repo_id,
+                images=images,
+                base_model=args.pretrained_model_name_or_path,
+                train_text_encoder=args.train_text_encoder,
+                instance_prompt=args.instance_prompt,
+                validation_prompt=args.validation_prompt,
+                repo_folder=args.output_dir,
+                vae_path=args.pretrained_vae_model_name_or_path,
+            )
+            upload_folder(
+                repo_id=repo_id,
+                folder_path=args.output_dir,
+                commit_message="End of training",
+                ignore_patterns=["step_*", "epoch_*"],
+            )
+
+    accelerator.end_training()
+
+
+if __name__ == "__main__":
+    args = parse_args()
+    main(args)