Update modules/sd_models.py

modules/sd_models.py

@@ -1,1034 +1,1037 @@
-import collections
-import importlib
-import os
-import sys
-import threading
-import enum
-
-import torch
-import re
-import safetensors.torch
-from omegaconf import OmegaConf, ListConfig
-from urllib import request
-import ldm.modules.midas as midas
-
-from modules import paths, shared, modelloader, devices, script_callbacks, sd_vae, sd_disable_initialization, errors, hashes, sd_models_config, sd_unet, sd_models_xl, cache, extra_networks, processing, lowvram, sd_hijack, patches
-from modules.timer import Timer
-from modules.shared import opts
-import tomesd
-import numpy as np
-
-model_dir = "Stable-diffusion"
-model_path = os.path.abspath(os.path.join(paths.models_path, model_dir))
-
-checkpoints_list = {}
-checkpoint_aliases = {}
-checkpoint_alisases = checkpoint_aliases  # for compatibility with old name
-checkpoints_loaded = collections.OrderedDict()
-
-
-class ModelType(enum.Enum):
-    SD1 = 1
-    SD2 = 2
-    SDXL = 3
-    SSD = 4
-    SD3 = 5
-
-
-def replace_key(d, key, new_key, value):
-    keys = list(d.keys())
-
-    d[new_key] = value
-
-    if key not in keys:
-        return d
-
-    index = keys.index(key)
-    keys[index] = new_key
-
-    new_d = {k: d[k] for k in keys}
-
-    d.clear()
-    d.update(new_d)
-    return d
-
-
-class CheckpointInfo:
-    def __init__(self, filename):
-        self.filename = filename
-        abspath = os.path.abspath(filename)
-        abs_ckpt_dir = os.path.abspath(shared.cmd_opts.ckpt_dir) if shared.cmd_opts.ckpt_dir is not None else None
-
-        self.is_safetensors = os.path.splitext(filename)[1].lower() == ".safetensors"
-
-        if abs_ckpt_dir and abspath.startswith(abs_ckpt_dir):
-            name = abspath.replace(abs_ckpt_dir, '')
-        elif abspath.startswith(model_path):
-            name = abspath.replace(model_path, '')
-        else:
-            name = os.path.basename(filename)
-
-        if name.startswith("\\") or name.startswith("/"):
-            name = name[1:]
-
-        def read_metadata():
-            metadata = read_metadata_from_safetensors(filename)
-            self.modelspec_thumbnail = metadata.pop('modelspec.thumbnail', None)
-
-            return metadata
-
-        self.metadata = {}
-        if self.is_safetensors:
-            try:
-                self.metadata = cache.cached_data_for_file('safetensors-metadata', "checkpoint/" + name, filename, read_metadata)
-            except Exception as e:
-                errors.display(e, f"reading metadata for {filename}")
-
-        self.name = name
-        self.name_for_extra = os.path.splitext(os.path.basename(filename))[0]
-        self.model_name = os.path.splitext(name.replace("/", "_").replace("\\", "_"))[0]
-        self.hash = model_hash(filename)
-
-        self.sha256 = hashes.sha256_from_cache(self.filename, f"checkpoint/{name}")
-        self.shorthash = self.sha256[0:10] if self.sha256 else None
-
-        self.title = name if self.shorthash is None else f'{name} [{self.shorthash}]'
-        self.short_title = self.name_for_extra if self.shorthash is None else f'{self.name_for_extra} [{self.shorthash}]'
-
-        self.ids = [self.hash, self.model_name, self.title, name, self.name_for_extra, f'{name} [{self.hash}]']
-        if self.shorthash:
-            self.ids += [self.shorthash, self.sha256, f'{self.name} [{self.shorthash}]', f'{self.name_for_extra} [{self.shorthash}]']
-
-    def register(self):
-        checkpoints_list[self.title] = self
-        for id in self.ids:
-            checkpoint_aliases[id] = self
-
-    def calculate_shorthash(self):
-        self.sha256 = hashes.sha256(self.filename, f"checkpoint/{self.name}")
-        if self.sha256 is None:
-            return
-
-        shorthash = self.sha256[0:10]
-        if self.shorthash == self.sha256[0:10]:
-            return self.shorthash
-
-        self.shorthash = shorthash
-
-        if self.shorthash not in self.ids:
-            self.ids += [self.shorthash, self.sha256, f'{self.name} [{self.shorthash}]', f'{self.name_for_extra} [{self.shorthash}]']
-
-        old_title = self.title
-        self.title = f'{self.name} [{self.shorthash}]'
-        self.short_title = f'{self.name_for_extra} [{self.shorthash}]'
-
-        replace_key(checkpoints_list, old_title, self.title, self)
-        self.register()
-
-        return self.shorthash
-
-
-try:
-    # this silences the annoying "Some weights of the model checkpoint were not used when initializing..." message at start.
-    from transformers import logging, CLIPModel  # noqa: F401
-
-    logging.set_verbosity_error()
-except Exception:
-    pass
-
-
-def setup_model():
-    """called once at startup to do various one-time tasks related to SD models"""
-
-    os.makedirs(model_path, exist_ok=True)
-
-    enable_midas_autodownload()
-    patch_given_betas()
-
-
-def checkpoint_tiles(use_short=False):
-    return [x.short_title if use_short else x.title for x in checkpoints_list.values()]
-
-
-def list_models():
-    checkpoints_list.clear()
-    checkpoint_aliases.clear()
-
-    cmd_ckpt = shared.cmd_opts.ckpt
-    if shared.cmd_opts.no_download_sd_model or cmd_ckpt != shared.sd_model_file or os.path.exists(cmd_ckpt):
-        model_url = None
-        expected_sha256 = None
-    else:
-        model_url = f"{shared.hf_endpoint}/runwayml/stable-diffusion-v1-5/resolve/main/v1-5-pruned-emaonly.safetensors"
-        expected_sha256 = '6ce0161689b3853acaa03779ec93eafe75a02f4ced659bee03f50797806fa2fa'
-
-    model_list = modelloader.load_models(model_path=model_path, model_url=model_url, command_path=shared.cmd_opts.ckpt_dir, ext_filter=[".ckpt", ".safetensors"], download_name="v1-5-pruned-emaonly.safetensors", ext_blacklist=[".vae.ckpt", ".vae.safetensors"], hash_prefix=expected_sha256)
-
-    if os.path.exists(cmd_ckpt):
-        checkpoint_info = CheckpointInfo(cmd_ckpt)
-        checkpoint_info.register()
-
-        shared.opts.data['sd_model_checkpoint'] = checkpoint_info.title
-    elif cmd_ckpt is not None and cmd_ckpt != shared.default_sd_model_file:
-        print(f"Checkpoint in --ckpt argument not found (Possible it was moved to {model_path}: {cmd_ckpt}", file=sys.stderr)
-
-    for filename in model_list:
-        checkpoint_info = CheckpointInfo(filename)
-        checkpoint_info.register()
-
-
-re_strip_checksum = re.compile(r"\s*\[[^]]+]\s*$")
-
-
-def get_closet_checkpoint_match(search_string):
-    if not search_string:
-        return None
-
-    checkpoint_info = checkpoint_aliases.get(search_string, None)
-    if checkpoint_info is not None:
-        return checkpoint_info
-
-    found = sorted([info for info in checkpoints_list.values() if search_string in info.title], key=lambda x: len(x.title))
-    if found:
-        return found[0]
-
-    search_string_without_checksum = re.sub(re_strip_checksum, '', search_string)
-    found = sorted([info for info in checkpoints_list.values() if search_string_without_checksum in info.title], key=lambda x: len(x.title))
-    if found:
-        return found[0]
-
-    return None
-
-
-def model_hash(filename):
-    """old hash that only looks at a small part of the file and is prone to collisions"""
-
-    try:
-        with open(filename, "rb") as file:
-            import hashlib
-            m = hashlib.sha256()
-
-            file.seek(0x100000)
-            m.update(file.read(0x10000))
-            return m.hexdigest()[0:8]
-    except FileNotFoundError:
-        return 'NOFILE'
-
-
-def select_checkpoint():
-    """Raises `FileNotFoundError` if no checkpoints are found."""
-    model_checkpoint = shared.opts.sd_model_checkpoint
-
-    checkpoint_info = checkpoint_aliases.get(model_checkpoint, None)
-    if checkpoint_info is not None:
-        return checkpoint_info
-
-    if len(checkpoints_list) == 0:
-        error_message = "No checkpoints found. When searching for checkpoints, looked at:"
-        if shared.cmd_opts.ckpt is not None:
-            error_message += f"\n - file {os.path.abspath(shared.cmd_opts.ckpt)}"
-        error_message += f"\n - directory {model_path}"
-        if shared.cmd_opts.ckpt_dir is not None:
-            error_message += f"\n - directory {os.path.abspath(shared.cmd_opts.ckpt_dir)}"
-        error_message += "Can't run without a checkpoint. Find and place a .ckpt or .safetensors file into any of those locations."
-        raise FileNotFoundError(error_message)
-
-    checkpoint_info = next(iter(checkpoints_list.values()))
-    if model_checkpoint is not None:
-        print(f"Checkpoint {model_checkpoint} not found; loading fallback {checkpoint_info.title}", file=sys.stderr)
-
-    return checkpoint_info
-
-
-checkpoint_dict_replacements_sd1 = {
-    'cond_stage_model.transformer.embeddings.': 'cond_stage_model.transformer.text_model.embeddings.',
-    'cond_stage_model.transformer.encoder.': 'cond_stage_model.transformer.text_model.encoder.',
-    'cond_stage_model.transformer.final_layer_norm.': 'cond_stage_model.transformer.text_model.final_layer_norm.',
-}
-
-checkpoint_dict_replacements_sd2_turbo = { # Converts SD 2.1 Turbo from SGM to LDM format.
-    'conditioner.embedders.0.': 'cond_stage_model.',
-}
-
-
-def transform_checkpoint_dict_key(k, replacements):
-    for text, replacement in replacements.items():
-        if k.startswith(text):
-            k = replacement + k[len(text):]
-
-    return k
-
-
-def get_state_dict_from_checkpoint(pl_sd):
-    pl_sd = pl_sd.pop("state_dict", pl_sd)
-    pl_sd.pop("state_dict", None)
-
-    is_sd2_turbo = 'conditioner.embedders.0.model.ln_final.weight' in pl_sd and pl_sd['conditioner.embedders.0.model.ln_final.weight'].size()[0] == 1024
-
-    sd = {}
-    for k, v in pl_sd.items():
-        if is_sd2_turbo:
-            new_key = transform_checkpoint_dict_key(k, checkpoint_dict_replacements_sd2_turbo)
-        else:
-            new_key = transform_checkpoint_dict_key(k, checkpoint_dict_replacements_sd1)
-
-        if new_key is not None:
-            sd[new_key] = v
-
-    pl_sd.clear()
-    pl_sd.update(sd)
-
-    return pl_sd
-
-
-def read_metadata_from_safetensors(filename):
-    import json
-
-    with open(filename, mode="rb") as file:
-        metadata_len = file.read(8)
-        metadata_len = int.from_bytes(metadata_len, "little")
-        json_start = file.read(2)
-
-        assert metadata_len > 2 and json_start in (b'{"', b"{'"), f"{filename} is not a safetensors file"
-
-        res = {}
-
-        try:
-            json_data = json_start + file.read(metadata_len-2)
-            json_obj = json.loads(json_data)
-            for k, v in json_obj.get("__metadata__", {}).items():
-                res[k] = v
-                if isinstance(v, str) and v[0:1] == '{':
-                    try:
-                        res[k] = json.loads(v)
-                    except Exception:
-                        pass
-        except Exception:
-             errors.report(f"Error reading metadata from file: {filename}", exc_info=True)
-
-        return res
-
-
-def read_state_dict(checkpoint_file, print_global_state=False, map_location=None):
-    _, extension = os.path.splitext(checkpoint_file)
-    if extension.lower() == ".safetensors":
-        device = map_location or shared.weight_load_location or devices.get_optimal_device_name()
-
-        if not shared.opts.disable_mmap_load_safetensors:
-            pl_sd = safetensors.torch.load_file(checkpoint_file, device=device)
-        else:
-            pl_sd = safetensors.torch.load(open(checkpoint_file, 'rb').read())
-            pl_sd = {k: v.to(device) for k, v in pl_sd.items()}
-    else:
-        pl_sd = torch.load(checkpoint_file, map_location=map_location or shared.weight_load_location)
-
-    if print_global_state and "global_step" in pl_sd:
-        print(f"Global Step: {pl_sd['global_step']}")
-
-    sd = get_state_dict_from_checkpoint(pl_sd)
-    return sd
-
-
-def get_checkpoint_state_dict(checkpoint_info: CheckpointInfo, timer):
-    sd_model_hash = checkpoint_info.calculate_shorthash()
-    timer.record("calculate hash")
-
-    if checkpoint_info in checkpoints_loaded:
-        # use checkpoint cache
-        print(f"Loading weights [{sd_model_hash}] from cache")
-        # move to end as latest
-        checkpoints_loaded.move_to_end(checkpoint_info)
-        return checkpoints_loaded[checkpoint_info]
-
-    print(f"Loading weights [{sd_model_hash}] from {checkpoint_info.filename}")
-    res = read_state_dict(checkpoint_info.filename)
-    timer.record("load weights from disk")
-
-    return res
-
-
-class SkipWritingToConfig:
-    """This context manager prevents load_model_weights from writing checkpoint name to the config when it loads weight."""
-
-    skip = False
-    previous = None
-
-    def __enter__(self):
-        self.previous = SkipWritingToConfig.skip
-        SkipWritingToConfig.skip = True
-        return self
-
-    def __exit__(self, exc_type, exc_value, exc_traceback):
-        SkipWritingToConfig.skip = self.previous
-
-
-def check_fp8(model):
-    if model is None:
-        return None
-    if devices.get_optimal_device_name() == "mps":
-        enable_fp8 = False
-    elif shared.opts.fp8_storage == "Enable":
-        enable_fp8 = True
-    elif getattr(model, "is_sdxl", False) and shared.opts.fp8_storage == "Enable for SDXL":
-        enable_fp8 = True
-    else:
-        enable_fp8 = False
-    return enable_fp8
-
-
-def set_model_type(model, state_dict):
-    model.is_sd1 = False
-    model.is_sd2 = False
-    model.is_sdxl = False
-    model.is_ssd = False
-    model.is_sd3 = False
-
-    if "model.diffusion_model.x_embedder.proj.weight" in state_dict:
-        model.is_sd3 = True
-        model.model_type = ModelType.SD3
-    elif hasattr(model, 'conditioner'):
-        model.is_sdxl = True
-
-        if 'model.diffusion_model.middle_block.1.transformer_blocks.0.attn1.to_q.weight' not in state_dict.keys():
-            model.is_ssd = True
-            model.model_type = ModelType.SSD
-        else:
-            model.model_type = ModelType.SDXL
-    elif hasattr(model.cond_stage_model, 'model'):
-        model.is_sd2 = True
-        model.model_type = ModelType.SD2
-    else:
-        model.is_sd1 = True
-        model.model_type = ModelType.SD1
-
-
-def set_model_fields(model):
-    if not hasattr(model, 'latent_channels'):
-        model.latent_channels = 4
-
-
-def load_model_weights(model, checkpoint_info: CheckpointInfo, state_dict, timer):
-    sd_model_hash = checkpoint_info.calculate_shorthash()
-    timer.record("calculate hash")
-
-    if devices.fp8:
-        # prevent model to load state dict in fp8
-        model.half()
-
-    if not SkipWritingToConfig.skip:
-        shared.opts.data["sd_model_checkpoint"] = checkpoint_info.title
-
-    if state_dict is None:
-        state_dict = get_checkpoint_state_dict(checkpoint_info, timer)
-
-    set_model_type(model, state_dict)
-    set_model_fields(model)
-
-    if model.is_sdxl:
-        sd_models_xl.extend_sdxl(model)
-
-    if model.is_ssd:
-        sd_hijack.model_hijack.convert_sdxl_to_ssd(model)
-
-    if shared.opts.sd_checkpoint_cache > 0:
-        # cache newly loaded model
-        checkpoints_loaded[checkpoint_info] = state_dict.copy()
-
-    if hasattr(model, "before_load_weights"):
-        model.before_load_weights(state_dict)
-
-    model.load_state_dict(state_dict, strict=False)
-    timer.record("apply weights to model")
-
-    if hasattr(model, "after_load_weights"):
-        model.after_load_weights(state_dict)
-
-    del state_dict
-
-    # Set is_sdxl_inpaint flag.
-    # Checks Unet structure to detect inpaint model. The inpaint model's
-    # checkpoint state_dict does not contain the key
-    # 'diffusion_model.input_blocks.0.0.weight'.
-    diffusion_model_input = model.model.state_dict().get(
-        'diffusion_model.input_blocks.0.0.weight'
-    )
-    model.is_sdxl_inpaint = (
-        model.is_sdxl and
-        diffusion_model_input is not None and
-        diffusion_model_input.shape[1] == 9
-    )
-
-    if shared.cmd_opts.opt_channelslast:
-        model.to(memory_format=torch.channels_last)
-        timer.record("apply channels_last")
-
-    if shared.cmd_opts.no_half:
-        model.float()
-        model.alphas_cumprod_original = model.alphas_cumprod
-        devices.dtype_unet = torch.float32
-        assert shared.cmd_opts.precision != "half", "Cannot use --precision half with --no-half"
-        timer.record("apply float()")
-    else:
-        vae = model.first_stage_model
-        depth_model = getattr(model, 'depth_model', None)
-
-        # with --no-half-vae, remove VAE from model when doing half() to prevent its weights from being converted to float16
-        if shared.cmd_opts.no_half_vae:
-            model.first_stage_model = None
-        # with --upcast-sampling, don't convert the depth model weights to float16
-        if shared.cmd_opts.upcast_sampling and depth_model:
-            model.depth_model = None
-
-        alphas_cumprod = model.alphas_cumprod
-        model.alphas_cumprod = None
-        model.half()
-        model.alphas_cumprod = alphas_cumprod
-        model.alphas_cumprod_original = alphas_cumprod
-        model.first_stage_model = vae
-        if depth_model:
-            model.depth_model = depth_model
-
-        devices.dtype_unet = torch.float16
-        timer.record("apply half()")
-
-    apply_alpha_schedule_override(model)
-
-    for module in model.modules():
-        if hasattr(module, 'fp16_weight'):
-            del module.fp16_weight
-        if hasattr(module, 'fp16_bias'):
-            del module.fp16_bias
-
-    if check_fp8(model):
-        devices.fp8 = True
-        first_stage = model.first_stage_model
-        model.first_stage_model = None
-        for module in model.modules():
-            if isinstance(module, (torch.nn.Conv2d, torch.nn.Linear)):
-                if shared.opts.cache_fp16_weight:
-                    module.fp16_weight = module.weight.data.clone().cpu().half()
-                    if module.bias is not None:
-                        module.fp16_bias = module.bias.data.clone().cpu().half()
-                module.to(torch.float8_e4m3fn)
-        model.first_stage_model = first_stage
-        timer.record("apply fp8")
-    else:
-        devices.fp8 = False
-
-    devices.unet_needs_upcast = shared.cmd_opts.upcast_sampling and devices.dtype == torch.float16 and devices.dtype_unet == torch.float16
-
-    model.first_stage_model.to(devices.dtype_vae)
-    timer.record("apply dtype to VAE")
-
-    # clean up cache if limit is reached
-    while len(checkpoints_loaded) > shared.opts.sd_checkpoint_cache:
-        checkpoints_loaded.popitem(last=False)
-
-    model.sd_model_hash = sd_model_hash
-    model.sd_model_checkpoint = checkpoint_info.filename
-    model.sd_checkpoint_info = checkpoint_info
-    shared.opts.data["sd_checkpoint_hash"] = checkpoint_info.sha256
-
-    if hasattr(model, 'logvar'):
-        model.logvar = model.logvar.to(devices.device)  # fix for training
-
-    sd_vae.delete_base_vae()
-    sd_vae.clear_loaded_vae()
-    vae_file, vae_source = sd_vae.resolve_vae(checkpoint_info.filename).tuple()
-    sd_vae.load_vae(model, vae_file, vae_source)
-    timer.record("load VAE")
-
-
-def enable_midas_autodownload():
-    """
-    Gives the ldm.modules.midas.api.load_model function automatic downloading.
-
-    When the 512-depth-ema model, and other future models like it, is loaded,
-    it calls midas.api.load_model to load the associated midas depth model.
-    This function applies a wrapper to download the model to the correct
-    location automatically.
-    """
-
-    midas_path = os.path.join(paths.models_path, 'midas')
-
-    # stable-diffusion-stability-ai hard-codes the midas model path to
-    # a location that differs from where other scripts using this model look.
-    # HACK: Overriding the path here.
-    for k, v in midas.api.ISL_PATHS.items():
-        file_name = os.path.basename(v)
-        midas.api.ISL_PATHS[k] = os.path.join(midas_path, file_name)
-
-    midas_urls = {
-        "dpt_large": "https://github.com/intel-isl/DPT/releases/download/1_0/dpt_large-midas-2f21e586.pt",
-        "dpt_hybrid": "https://github.com/intel-isl/DPT/releases/download/1_0/dpt_hybrid-midas-501f0c75.pt",
-        "midas_v21": "https://github.com/AlexeyAB/MiDaS/releases/download/midas_dpt/midas_v21-f6b98070.pt",
-        "midas_v21_small": "https://github.com/AlexeyAB/MiDaS/releases/download/midas_dpt/midas_v21_small-70d6b9c8.pt",
-    }
-
-    midas.api.load_model_inner = midas.api.load_model
-
-    def load_model_wrapper(model_type):
-        path = midas.api.ISL_PATHS[model_type]
-        if not os.path.exists(path):
-            if not os.path.exists(midas_path):
-                os.mkdir(midas_path)
-
-            print(f"Downloading midas model weights for {model_type} to {path}")
-            request.urlretrieve(midas_urls[model_type], path)
-            print(f"{model_type} downloaded")
-
-        return midas.api.load_model_inner(model_type)
-
-    midas.api.load_model = load_model_wrapper
-
-
-def patch_given_betas():
-    import ldm.models.diffusion.ddpm
-
-    def patched_register_schedule(*args, **kwargs):
-        """a modified version of register_schedule function that converts plain list from Omegaconf into numpy"""
-
-        if isinstance(args[1], ListConfig):
-            args = (args[0], np.array(args[1]), *args[2:])
-
-        original_register_schedule(*args, **kwargs)
-
-    original_register_schedule = patches.patch(__name__, ldm.models.diffusion.ddpm.DDPM, 'register_schedule', patched_register_schedule)
-
-
-def repair_config(sd_config, state_dict=None):
-    if not hasattr(sd_config.model.params, "use_ema"):
-        sd_config.model.params.use_ema = False
-
-    if hasattr(sd_config.model.params, 'unet_config'):
-        if shared.cmd_opts.no_half:
-            sd_config.model.params.unet_config.params.use_fp16 = False
-        elif shared.cmd_opts.upcast_sampling or shared.cmd_opts.precision == "half":
-            sd_config.model.params.unet_config.params.use_fp16 = True
-
-    if hasattr(sd_config.model.params, 'first_stage_config'):
-        if getattr(sd_config.model.params.first_stage_config.params.ddconfig, "attn_type", None) == "vanilla-xformers" and not shared.xformers_available:
-            sd_config.model.params.first_stage_config.params.ddconfig.attn_type = "vanilla"
-
-    # For UnCLIP-L, override the hardcoded karlo directory
-    if hasattr(sd_config.model.params, "noise_aug_config") and hasattr(sd_config.model.params.noise_aug_config.params, "clip_stats_path"):
-        karlo_path = os.path.join(paths.models_path, 'karlo')
-        sd_config.model.params.noise_aug_config.params.clip_stats_path = sd_config.model.params.noise_aug_config.params.clip_stats_path.replace("checkpoints/karlo_models", karlo_path)
-
-    # Do not use checkpoint for inference.
-    # This helps prevent extra performance overhead on checking parameters.
-    # The perf overhead is about 100ms/it on 4090 for SDXL.
-    if hasattr(sd_config.model.params, "network_config"):
-        sd_config.model.params.network_config.params.use_checkpoint = False
-    if hasattr(sd_config.model.params, "unet_config"):
-        sd_config.model.params.unet_config.params.use_checkpoint = False
-
-
-
-def rescale_zero_terminal_snr_abar(alphas_cumprod):
-    alphas_bar_sqrt = alphas_cumprod.sqrt()
-
-    # Store old values.
-    alphas_bar_sqrt_0 = alphas_bar_sqrt[0].clone()
-    alphas_bar_sqrt_T = alphas_bar_sqrt[-1].clone()
-
-    # Shift so the last timestep is zero.
-    alphas_bar_sqrt -= (alphas_bar_sqrt_T)
-
-    # Scale so the first timestep is back to the old value.
-    alphas_bar_sqrt *= alphas_bar_sqrt_0 / (alphas_bar_sqrt_0 - alphas_bar_sqrt_T)
-
-    # Convert alphas_bar_sqrt to betas
-    alphas_bar = alphas_bar_sqrt ** 2  # Revert sqrt
-    alphas_bar[-1] = 4.8973451890853435e-08
-    return alphas_bar
-
-
-def apply_alpha_schedule_override(sd_model, p=None):
-    """
-    Applies an override to the alpha schedule of the model according to settings.
-    - downcasts the alpha schedule to half precision
-    - rescales the alpha schedule to have zero terminal SNR
-    """
-
-    if not hasattr(sd_model, 'alphas_cumprod') or not hasattr(sd_model, 'alphas_cumprod_original'):
-        return
-
-    sd_model.alphas_cumprod = sd_model.alphas_cumprod_original.to(shared.device)
-
-    if opts.use_downcasted_alpha_bar:
-        if p is not None:
-            p.extra_generation_params['Downcast alphas_cumprod'] = opts.use_downcasted_alpha_bar
-        sd_model.alphas_cumprod = sd_model.alphas_cumprod.half().to(shared.device)
-
-    if opts.sd_noise_schedule == "Zero Terminal SNR":
-        if p is not None:
-            p.extra_generation_params['Noise Schedule'] = opts.sd_noise_schedule
-        sd_model.alphas_cumprod = rescale_zero_terminal_snr_abar(sd_model.alphas_cumprod).to(shared.device)
-
-
-sd1_clip_weight = 'cond_stage_model.transformer.text_model.embeddings.token_embedding.weight'
-sd2_clip_weight = 'cond_stage_model.model.transformer.resblocks.0.attn.in_proj_weight'
-sdxl_clip_weight = 'conditioner.embedders.1.model.ln_final.weight'
-sdxl_refiner_clip_weight = 'conditioner.embedders.0.model.ln_final.weight'
-
-
-class SdModelData:
-    def __init__(self):
-        self.sd_model = None
-        self.loaded_sd_models = []
-        self.was_loaded_at_least_once = False
-        self.lock = threading.Lock()
-
-    def get_sd_model(self):
-        if self.was_loaded_at_least_once:
-            return self.sd_model
-
-        if self.sd_model is None:
-            with self.lock:
-                if self.sd_model is not None or self.was_loaded_at_least_once:
-                    return self.sd_model
-
-                try:
-                    load_model()
-
-                except Exception as e:
-                    errors.display(e, "loading stable diffusion model", full_traceback=True)
-                    print("", file=sys.stderr)
-                    print("Stable diffusion model failed to load", file=sys.stderr)
-                    self.sd_model = None
-
-        return self.sd_model
-
-    def set_sd_model(self, v, already_loaded=False):
-        self.sd_model = v
-        if already_loaded:
-            sd_vae.base_vae = getattr(v, "base_vae", None)
-            sd_vae.loaded_vae_file = getattr(v, "loaded_vae_file", None)
-            sd_vae.checkpoint_info = v.sd_checkpoint_info
-
-        try:
-            self.loaded_sd_models.remove(v)
-        except ValueError:
-            pass
-
-        if v is not None:
-            self.loaded_sd_models.insert(0, v)
-
-
-model_data = SdModelData()
-
-
-def get_empty_cond(sd_model):
-
-    p = processing.StableDiffusionProcessingTxt2Img()
-    extra_networks.activate(p, {})
-
-    if hasattr(sd_model, 'get_learned_conditioning'):
-        d = sd_model.get_learned_conditioning([""])
-    else:
-        d = sd_model.cond_stage_model([""])
-
-    if isinstance(d, dict):
-        d = d['crossattn']
-
-    return d
-
-
-def send_model_to_cpu(m):
-    if m is not None:
-        if m.lowvram:
-            lowvram.send_everything_to_cpu()
-        else:
-            m.to(devices.cpu)
-
-    devices.torch_gc()
-
-
-def model_target_device(m):
-    if lowvram.is_needed(m):
-        return devices.cpu
-    else:
-        return devices.device
-
-
-def send_model_to_device(m):
-    lowvram.apply(m)
-
-    if not m.lowvram:
-        m.to(shared.device)
-
-
-def send_model_to_trash(m):
-    m.to(device="meta")
-    devices.torch_gc()
-
-
-def instantiate_from_config(config, state_dict=None):
-    constructor = get_obj_from_str(config["target"])
-
-    params = {**config.get("params", {})}
-
-    if state_dict and "state_dict" in params and params["state_dict"] is None:
-        params["state_dict"] = state_dict
-
-    return constructor(**params)
-
-
-def get_obj_from_str(string, reload=False):
-    module, cls = string.rsplit(".", 1)
-    if reload:
-        module_imp = importlib.import_module(module)
-        importlib.reload(module_imp)
-    return getattr(importlib.import_module(module, package=None), cls)
-
-
-def load_model(checkpoint_info=None, already_loaded_state_dict=None):
-    from modules import sd_hijack
-    checkpoint_info = checkpoint_info or select_checkpoint()
-
-    timer = Timer()
-
-    if model_data.sd_model:
-        send_model_to_trash(model_data.sd_model)
-        model_data.sd_model = None
-        devices.torch_gc()
-
-    timer.record("unload existing model")
-
-    if already_loaded_state_dict is not None:
-        state_dict = already_loaded_state_dict
-    else:
-        state_dict = get_checkpoint_state_dict(checkpoint_info, timer)
-
-    checkpoint_config = sd_models_config.find_checkpoint_config(state_dict, checkpoint_info)
-    clip_is_included_into_sd = any(x for x in [sd1_clip_weight, sd2_clip_weight, sdxl_clip_weight, sdxl_refiner_clip_weight] if x in state_dict)
-
-    timer.record("find config")
-
-    sd_config = OmegaConf.load(checkpoint_config)
-    repair_config(sd_config, state_dict)
-
-    timer.record("load config")
-
-    print(f"Creating model from config: {checkpoint_config}")
-
-    sd_model = None
-    try:
-        with sd_disable_initialization.DisableInitialization(disable_clip=clip_is_included_into_sd or shared.cmd_opts.do_not_download_clip):
-            with sd_disable_initialization.InitializeOnMeta():
-                sd_model = instantiate_from_config(sd_config.model, state_dict)
-
-    except Exception as e:
-        errors.display(e, "creating model quickly", full_traceback=True)
-
-    if sd_model is None:
-        print('Failed to create model quickly; will retry using slow method.', file=sys.stderr)
-
-        with sd_disable_initialization.InitializeOnMeta():
-            sd_model = instantiate_from_config(sd_config.model, state_dict)
-
-    sd_model.used_config = checkpoint_config
-
-    timer.record("create model")
-
-    if shared.cmd_opts.no_half:
-        weight_dtype_conversion = None
-    else:
-        weight_dtype_conversion = {
-            'first_stage_model': None,
-            'alphas_cumprod': None,
-            '': torch.float16,
-        }
-
-    with sd_disable_initialization.LoadStateDictOnMeta(state_dict, device=model_target_device(sd_model), weight_dtype_conversion=weight_dtype_conversion):
-        load_model_weights(sd_model, checkpoint_info, state_dict, timer)
-
-    timer.record("load weights from state dict")
-
-    send_model_to_device(sd_model)
-    timer.record("move model to device")
-
-    sd_hijack.model_hijack.hijack(sd_model)
-
-    timer.record("hijack")
-
-    sd_model.eval()
-    model_data.set_sd_model(sd_model)
-    model_data.was_loaded_at_least_once = True
-
-    sd_hijack.model_hijack.embedding_db.load_textual_inversion_embeddings(force_reload=True)  # Reload embeddings after model load as they may or may not fit the model
-
-    timer.record("load textual inversion embeddings")
-
-    script_callbacks.model_loaded_callback(sd_model)
-
-    timer.record("scripts callbacks")
-
-    with devices.autocast(), torch.no_grad():
-        sd_model.cond_stage_model_empty_prompt = get_empty_cond(sd_model)
-
-    timer.record("calculate empty prompt")
-
-    print(f"Model loaded in {timer.summary()}.")
-
-    return sd_model
-
-
-def reuse_model_from_already_loaded(sd_model, checkpoint_info, timer):
-    """
-    Checks if the desired checkpoint from checkpoint_info is not already loaded in model_data.loaded_sd_models.
-    If it is loaded, returns that (moving it to GPU if necessary, and moving the currently loadded model to CPU if necessary).
-    If not, returns the model that can be used to load weights from checkpoint_info's file.
-    If no such model exists, returns None.
-    Additionally deletes loaded models that are over the limit set in settings (sd_checkpoints_limit).
-    """
-
-    if sd_model is not None and sd_model.sd_checkpoint_info.filename == checkpoint_info.filename:
-        return sd_model
-
-    if shared.opts.sd_checkpoints_keep_in_cpu:
-        send_model_to_cpu(sd_model)
-        timer.record("send model to cpu")
-
-    already_loaded = None
-    for i in reversed(range(len(model_data.loaded_sd_models))):
-        loaded_model = model_data.loaded_sd_models[i]
-        if loaded_model.sd_checkpoint_info.filename == checkpoint_info.filename:
-            already_loaded = loaded_model
-            continue
-
-        if len(model_data.loaded_sd_models) > shared.opts.sd_checkpoints_limit > 0:
-            print(f"Unloading model {len(model_data.loaded_sd_models)} over the limit of {shared.opts.sd_checkpoints_limit}: {loaded_model.sd_checkpoint_info.title}")
-            del model_data.loaded_sd_models[i]
-            send_model_to_trash(loaded_model)
-            timer.record("send model to trash")
-
-    if already_loaded is not None:
-        send_model_to_device(already_loaded)
-        timer.record("send model to device")
-
-        model_data.set_sd_model(already_loaded, already_loaded=True)
-
-        if not SkipWritingToConfig.skip:
-            shared.opts.data["sd_model_checkpoint"] = already_loaded.sd_checkpoint_info.title
-            shared.opts.data["sd_checkpoint_hash"] = already_loaded.sd_checkpoint_info.sha256
-
-        print(f"Using already loaded model {already_loaded.sd_checkpoint_info.title}: done in {timer.summary()}")
-        sd_vae.reload_vae_weights(already_loaded)
-        return model_data.sd_model
-    elif shared.opts.sd_checkpoints_limit > 1 and len(model_data.loaded_sd_models) < shared.opts.sd_checkpoints_limit:
-        print(f"Loading model {checkpoint_info.title} ({len(model_data.loaded_sd_models) + 1} out of {shared.opts.sd_checkpoints_limit})")
-
-        model_data.sd_model = None
-        load_model(checkpoint_info)
-        return model_data.sd_model
-    elif len(model_data.loaded_sd_models) > 0:
-        sd_model = model_data.loaded_sd_models.pop()
-        model_data.sd_model = sd_model
-
-        sd_vae.base_vae = getattr(sd_model, "base_vae", None)
-        sd_vae.loaded_vae_file = getattr(sd_model, "loaded_vae_file", None)
-        sd_vae.checkpoint_info = sd_model.sd_checkpoint_info
-
-        print(f"Reusing loaded model {sd_model.sd_checkpoint_info.title} to load {checkpoint_info.title}")
-        return sd_model
-    else:
-        return None
-
-
-def reload_model_weights(sd_model=None, info=None, forced_reload=False):
-    checkpoint_info = info or select_checkpoint()
-
-    timer = Timer()
-
-    if not sd_model:
-        sd_model = model_data.sd_model
-
-    if sd_model is None:  # previous model load failed
-        current_checkpoint_info = None
-    else:
-        current_checkpoint_info = sd_model.sd_checkpoint_info
-        if check_fp8(sd_model) != devices.fp8:
-            # load from state dict again to prevent extra numerical errors
-            forced_reload = True
-        elif sd_model.sd_model_checkpoint == checkpoint_info.filename and not forced_reload:
-            return sd_model
-
-    sd_model = reuse_model_from_already_loaded(sd_model, checkpoint_info, timer)
-    if not forced_reload and sd_model is not None and sd_model.sd_checkpoint_info.filename == checkpoint_info.filename:
-        return sd_model
-
-    if sd_model is not None:
-        sd_unet.apply_unet("None")
-        send_model_to_cpu(sd_model)
-        sd_hijack.model_hijack.undo_hijack(sd_model)
-
-    state_dict = get_checkpoint_state_dict(checkpoint_info, timer)
-
-    checkpoint_config = sd_models_config.find_checkpoint_config(state_dict, checkpoint_info)
-
-    timer.record("find config")
-
-    if sd_model is None or checkpoint_config != sd_model.used_config:
-        if sd_model is not None:
-            send_model_to_trash(sd_model)
-
-        load_model(checkpoint_info, already_loaded_state_dict=state_dict)
-        return model_data.sd_model
-
-    try:
-        load_model_weights(sd_model, checkpoint_info, state_dict, timer)
-    except Exception:
-        print("Failed to load checkpoint, restoring previous")
-        load_model_weights(sd_model, current_checkpoint_info, None, timer)
-        raise
-    finally:
-        sd_hijack.model_hijack.hijack(sd_model)
-        timer.record("hijack")
-
-        if not sd_model.lowvram:
-            sd_model.to(devices.device)
-            timer.record("move model to device")
-
-        script_callbacks.model_loaded_callback(sd_model)
-        timer.record("script callbacks")
-
-    print(f"Weights loaded in {timer.summary()}.")
-
-    model_data.set_sd_model(sd_model)
-    sd_unet.apply_unet()
-
-    return sd_model
-
-
-def unload_model_weights(sd_model=None, info=None):
-    send_model_to_cpu(sd_model or shared.sd_model)
-
-    return sd_model
-
-
-def apply_token_merging(sd_model, token_merging_ratio):
-    """
-    Applies speed and memory optimizations from tomesd.
-    """
-
-    current_token_merging_ratio = getattr(sd_model, 'applied_token_merged_ratio', 0)
-
-    if current_token_merging_ratio == token_merging_ratio:
-        return
-
-    if current_token_merging_ratio > 0:
-        tomesd.remove_patch(sd_model)
-
-    if token_merging_ratio > 0:
-        tomesd.apply_patch(
-            sd_model,
-            ratio=token_merging_ratio,
-            use_rand=False,  # can cause issues with some samplers
-            merge_attn=True,
-            merge_crossattn=False,
-            merge_mlp=False
-        )
-
-    sd_model.applied_token_merged_ratio = token_merging_ratio
+import collections
+import importlib
+import os
+import sys
+import threading
+import enum
+
+import torch
+import re
+import safetensors.torch
+from omegaconf import OmegaConf, ListConfig
+from urllib import request
+import ldm.modules.midas as midas
+
+from modules import paths, shared, modelloader, devices, script_callbacks, sd_vae, sd_disable_initialization, errors, hashes, sd_models_config, sd_unet, sd_models_xl, cache, extra_networks, processing, lowvram, sd_hijack, patches
+from modules.timer import Timer
+from modules.shared import opts
+import tomesd
+import numpy as np
+
+model_dir = "Stable-diffusion"
+model_path = os.path.abspath(os.path.join(paths.models_path, model_dir))
+
+checkpoints_list = {}
+checkpoint_aliases = {}
+checkpoint_alisases = checkpoint_aliases  # for compatibility with old name
+checkpoints_loaded = collections.OrderedDict()
+
+
+class ModelType(enum.Enum):
+    SD1 = 1
+    SD2 = 2
+    SDXL = 3
+    SSD = 4
+    SD3 = 5
+
+
+def replace_key(d, key, new_key, value):
+    keys = list(d.keys())
+
+    d[new_key] = value
+
+    if key not in keys:
+        return d
+
+    index = keys.index(key)
+    keys[index] = new_key
+
+    new_d = {k: d[k] for k in keys}
+
+    d.clear()
+    d.update(new_d)
+    return d
+
+
+class CheckpointInfo:
+    def __init__(self, filename):
+        self.filename = filename
+        abspath = os.path.abspath(filename)
+        abs_ckpt_dir = os.path.abspath(shared.cmd_opts.ckpt_dir) if shared.cmd_opts.ckpt_dir is not None else None
+
+        self.is_safetensors = os.path.splitext(filename)[1].lower() == ".safetensors"
+
+        if abs_ckpt_dir and abspath.startswith(abs_ckpt_dir):
+            name = abspath.replace(abs_ckpt_dir, '')
+        elif abspath.startswith(model_path):
+            name = abspath.replace(model_path, '')
+        else:
+            name = os.path.basename(filename)
+
+        if name.startswith("\\") or name.startswith("/"):
+            name = name[1:]
+
+        def read_metadata():
+            metadata = read_metadata_from_safetensors(filename)
+            self.modelspec_thumbnail = metadata.pop('modelspec.thumbnail', None)
+
+            return metadata
+
+        self.metadata = {}
+        if self.is_safetensors:
+            try:
+                self.metadata = cache.cached_data_for_file('safetensors-metadata', "checkpoint/" + name, filename, read_metadata)
+            except Exception as e:
+                errors.display(e, f"reading metadata for {filename}")
+
+        self.name = name
+        self.name_for_extra = os.path.splitext(os.path.basename(filename))[0]
+        self.model_name = os.path.splitext(name.replace("/", "_").replace("\\", "_"))[0]
+        self.hash = model_hash(filename)
+
+        self.sha256 = hashes.sha256_from_cache(self.filename, f"checkpoint/{name}")
+        self.shorthash = self.sha256[0:10] if self.sha256 else None
+
+        self.title = name if self.shorthash is None else f'{name} [{self.shorthash}]'
+        self.short_title = self.name_for_extra if self.shorthash is None else f'{self.name_for_extra} [{self.shorthash}]'
+
+        self.ids = [self.hash, self.model_name, self.title, name, self.name_for_extra, f'{name} [{self.hash}]']
+        if self.shorthash:
+            self.ids += [self.shorthash, self.sha256, f'{self.name} [{self.shorthash}]', f'{self.name_for_extra} [{self.shorthash}]']
+
+    def register(self):
+        checkpoints_list[self.title] = self
+        for id in self.ids:
+            checkpoint_aliases[id] = self
+
+    def calculate_shorthash(self):
+        self.sha256 = hashes.sha256(self.filename, f"checkpoint/{self.name}")
+        if self.sha256 is None:
+            return
+
+        shorthash = self.sha256[0:10]
+        if self.shorthash == self.sha256[0:10]:
+            return self.shorthash
+
+        self.shorthash = shorthash
+
+        if self.shorthash not in self.ids:
+            self.ids += [self.shorthash, self.sha256, f'{self.name} [{self.shorthash}]', f'{self.name_for_extra} [{self.shorthash}]']
+
+        old_title = self.title
+        self.title = f'{self.name} [{self.shorthash}]'
+        self.short_title = f'{self.name_for_extra} [{self.shorthash}]'
+
+        replace_key(checkpoints_list, old_title, self.title, self)
+        self.register()
+
+        return self.shorthash
+
+
+try:
+    # this silences the annoying "Some weights of the model checkpoint were not used when initializing..." message at start.
+    from transformers import logging, CLIPModel  # noqa: F401
+
+    logging.set_verbosity_error()
+except Exception:
+    pass
+
+
+def setup_model():
+    """called once at startup to do various one-time tasks related to SD models"""
+
+    os.makedirs(model_path, exist_ok=True)
+
+    enable_midas_autodownload()
+    patch_given_betas()
+
+
+def checkpoint_tiles(use_short=False):
+    return [x.short_title if use_short else x.title for x in checkpoints_list.values()]
+
+
+def list_models():
+    checkpoints_list.clear()
+    checkpoint_aliases.clear()
+
+    cmd_ckpt = shared.cmd_opts.ckpt
+    if shared.cmd_opts.no_download_sd_model or cmd_ckpt != shared.sd_model_file or os.path.exists(cmd_ckpt):
+        model_url = None
+        expected_sha256 = None
+    else:
+        model_url = f"{shared.hf_endpoint}/runwayml/stable-diffusion-v1-5/resolve/main/v1-5-pruned-emaonly.safetensors"
+        expected_sha256 = '6ce0161689b3853acaa03779ec93eafe75a02f4ced659bee03f50797806fa2fa'
+
+    model_list = modelloader.load_models(model_path=model_path, model_url=model_url, command_path=shared.cmd_opts.ckpt_dir, ext_filter=[".ckpt", ".safetensors"], download_name="v1-5-pruned-emaonly.safetensors", ext_blacklist=[".vae.ckpt", ".vae.safetensors"], hash_prefix=expected_sha256)
+
+    if os.path.exists(cmd_ckpt):
+        checkpoint_info = CheckpointInfo(cmd_ckpt)
+        checkpoint_info.register()
+
+        shared.opts.data['sd_model_checkpoint'] = checkpoint_info.title
+    elif cmd_ckpt is not None and cmd_ckpt != shared.default_sd_model_file:
+        print(f"Checkpoint in --ckpt argument not found (Possible it was moved to {model_path}: {cmd_ckpt}", file=sys.stderr)
+
+    for filename in model_list:
+        checkpoint_info = CheckpointInfo(filename)
+        checkpoint_info.register()
+
+
+re_strip_checksum = re.compile(r"\s*\[[^]]+]\s*$")
+
+
+def get_closet_checkpoint_match(search_string):
+    if not search_string:
+        return None
+
+    checkpoint_info = checkpoint_aliases.get(search_string, None)
+    if checkpoint_info is not None:
+        return checkpoint_info
+
+    found = sorted([info for info in checkpoints_list.values() if search_string in info.title], key=lambda x: len(x.title))
+    if found:
+        return found[0]
+
+    search_string_without_checksum = re.sub(re_strip_checksum, '', search_string)
+    found = sorted([info for info in checkpoints_list.values() if search_string_without_checksum in info.title], key=lambda x: len(x.title))
+    if found:
+        return found[0]
+
+    return None
+
+
+def model_hash(filename):
+    """old hash that only looks at a small part of the file and is prone to collisions"""
+
+    try:
+        with open(filename, "rb") as file:
+            import hashlib
+            m = hashlib.sha256()
+
+            file.seek(0x100000)
+            m.update(file.read(0x10000))
+            return m.hexdigest()[0:8]
+    except FileNotFoundError:
+        return 'NOFILE'
+
+
+def select_checkpoint():
+    """Raises `FileNotFoundError` if no checkpoints are found."""
+    model_checkpoint = shared.opts.sd_model_checkpoint
+
+    checkpoint_info = checkpoint_aliases.get(model_checkpoint, None)
+    if checkpoint_info is not None:
+        return checkpoint_info
+
+    if len(checkpoints_list) == 0:
+        error_message = "No checkpoints found. When searching for checkpoints, looked at:"
+        if shared.cmd_opts.ckpt is not None:
+            error_message += f"\n - file {os.path.abspath(shared.cmd_opts.ckpt)}"
+        error_message += f"\n - directory {model_path}"
+        if shared.cmd_opts.ckpt_dir is not None:
+            error_message += f"\n - directory {os.path.abspath(shared.cmd_opts.ckpt_dir)}"
+        error_message += "Can't run without a checkpoint. Find and place a .ckpt or .safetensors file into any of those locations."
+        raise FileNotFoundError(error_message)
+
+    checkpoint_info = next(iter(checkpoints_list.values()))
+    if model_checkpoint is not None:
+        print(f"Checkpoint {model_checkpoint} not found; loading fallback {checkpoint_info.title}", file=sys.stderr)
+
+    return checkpoint_info
+
+
+checkpoint_dict_replacements_sd1 = {
+    'cond_stage_model.transformer.embeddings.': 'cond_stage_model.transformer.text_model.embeddings.',
+    'cond_stage_model.transformer.encoder.': 'cond_stage_model.transformer.text_model.encoder.',
+    'cond_stage_model.transformer.final_layer_norm.': 'cond_stage_model.transformer.text_model.final_layer_norm.',
+}
+
+checkpoint_dict_replacements_sd2_turbo = { # Converts SD 2.1 Turbo from SGM to LDM format.
+    'conditioner.embedders.0.': 'cond_stage_model.',
+}
+
+
+def transform_checkpoint_dict_key(k, replacements):
+    for text, replacement in replacements.items():
+        if k.startswith(text):
+            k = replacement + k[len(text):]
+
+    return k
+
+
+def get_state_dict_from_checkpoint(pl_sd):
+    pl_sd = pl_sd.pop("state_dict", pl_sd)
+    pl_sd.pop("state_dict", None)
+
+    is_sd2_turbo = 'conditioner.embedders.0.model.ln_final.weight' in pl_sd and pl_sd['conditioner.embedders.0.model.ln_final.weight'].size()[0] == 1024
+
+    sd = {}
+    for k, v in pl_sd.items():
+        if is_sd2_turbo:
+            new_key = transform_checkpoint_dict_key(k, checkpoint_dict_replacements_sd2_turbo)
+        else:
+            new_key = transform_checkpoint_dict_key(k, checkpoint_dict_replacements_sd1)
+
+        if new_key is not None:
+            sd[new_key] = v
+
+    pl_sd.clear()
+    pl_sd.update(sd)
+
+    return pl_sd
+
+
+def read_metadata_from_safetensors(filename):
+    import json
+
+    with open(filename, mode="rb") as file:
+        metadata_len = file.read(8)
+        metadata_len = int.from_bytes(metadata_len, "little")
+        json_start = file.read(2)
+
+        assert metadata_len > 2 and json_start in (b'{"', b"{'"), f"{filename} is not a safetensors file"
+
+        res = {}
+
+        try:
+            json_data = json_start + file.read(metadata_len-2)
+            json_obj = json.loads(json_data)
+            for k, v in json_obj.get("__metadata__", {}).items():
+                res[k] = v
+                if isinstance(v, str) and v[0:1] == '{':
+                    try:
+                        res[k] = json.loads(v)
+                    except Exception:
+                        pass
+        except Exception:
+             errors.report(f"Error reading metadata from file: {filename}", exc_info=True)
+
+        return res
+
+
+def read_state_dict(checkpoint_file, print_global_state=False, map_location=None):
+    _, extension = os.path.splitext(checkpoint_file)
+    if extension.lower() == ".safetensors":
+        device = map_location or shared.weight_load_location or devices.get_optimal_device_name()
+
+        if not shared.opts.disable_mmap_load_safetensors:
+            pl_sd = safetensors.torch.load_file(checkpoint_file, device=device)
+        else:
+            pl_sd = safetensors.torch.load(open(checkpoint_file, 'rb').read())
+            pl_sd = {k: v.to(device) for k, v in pl_sd.items()}
+    else:
+        pl_sd = torch.load(checkpoint_file, map_location=map_location or shared.weight_load_location)
+
+    if print_global_state and "global_step" in pl_sd:
+        print(f"Global Step: {pl_sd['global_step']}")
+
+    sd = get_state_dict_from_checkpoint(pl_sd)
+    return sd
+
+
+def get_checkpoint_state_dict(checkpoint_info: CheckpointInfo, timer):
+    sd_model_hash = checkpoint_info.calculate_shorthash()
+    timer.record("calculate hash")
+
+    if checkpoint_info in checkpoints_loaded:
+        # use checkpoint cache
+        print(f"Loading weights [{sd_model_hash}] from cache")
+        # move to end as latest
+        checkpoints_loaded.move_to_end(checkpoint_info)
+        return checkpoints_loaded[checkpoint_info]
+
+    print(f"Loading weights [{sd_model_hash}] from {checkpoint_info.filename}")
+    res = read_state_dict(checkpoint_info.filename)
+    timer.record("load weights from disk")
+
+    return res
+
+
+class SkipWritingToConfig:
+    """This context manager prevents load_model_weights from writing checkpoint name to the config when it loads weight."""
+
+    skip = False
+    previous = None
+
+    def __enter__(self):
+        self.previous = SkipWritingToConfig.skip
+        SkipWritingToConfig.skip = True
+        return self
+
+    def __exit__(self, exc_type, exc_value, exc_traceback):
+        SkipWritingToConfig.skip = self.previous
+
+
+def check_fp8(model):
+    if model is None:
+        return None
+    if devices.get_optimal_device_name() == "mps":
+        enable_fp8 = False
+    elif shared.opts.fp8_storage == "Enable":
+        enable_fp8 = True
+    elif getattr(model, "is_sdxl", False) and shared.opts.fp8_storage == "Enable for SDXL":
+        enable_fp8 = True
+    else:
+        enable_fp8 = False
+    return enable_fp8
+
+
+def set_model_type(model, state_dict):
+    model.is_sd1 = False
+    model.is_sd2 = False
+    model.is_sdxl = False
+    model.is_ssd = False
+    model.is_sd3 = False
+
+    if "model.diffusion_model.x_embedder.proj.weight" in state_dict:
+        model.is_sd3 = True
+        model.model_type = ModelType.SD3
+    elif hasattr(model, 'conditioner'):
+        model.is_sdxl = True
+
+        if 'model.diffusion_model.middle_block.1.transformer_blocks.0.attn1.to_q.weight' not in state_dict.keys():
+            model.is_ssd = True
+            model.model_type = ModelType.SSD
+        else:
+            model.model_type = ModelType.SDXL
+    elif hasattr(model.cond_stage_model, 'model'):
+        model.is_sd2 = True
+        model.model_type = ModelType.SD2
+    else:
+        model.is_sd1 = True
+        model.model_type = ModelType.SD1
+
+
+def set_model_fields(model):
+    if not hasattr(model, 'latent_channels'):
+        model.latent_channels = 4
+
+
+def load_model_weights(model, checkpoint_info: CheckpointInfo, state_dict, timer):
+    sd_model_hash = checkpoint_info.calculate_shorthash()
+    timer.record("calculate hash")
+
+    if devices.fp8:
+        # prevent model to load state dict in fp8
+        if torch.cuda.is_available():
+        model.half()
+       
+
+    if not SkipWritingToConfig.skip:
+        shared.opts.data["sd_model_checkpoint"] = checkpoint_info.title
+
+    if state_dict is None:
+        state_dict = get_checkpoint_state_dict(checkpoint_info, timer)
+
+    set_model_type(model, state_dict)
+    set_model_fields(model)
+
+    if model.is_sdxl:
+        sd_models_xl.extend_sdxl(model)
+
+    if model.is_ssd:
+        sd_hijack.model_hijack.convert_sdxl_to_ssd(model)
+
+    if shared.opts.sd_checkpoint_cache > 0:
+        # cache newly loaded model
+        checkpoints_loaded[checkpoint_info] = state_dict.copy()
+
+    if hasattr(model, "before_load_weights"):
+        model.before_load_weights(state_dict)
+
+    model.load_state_dict(state_dict, strict=False)
+    timer.record("apply weights to model")
+
+    if hasattr(model, "after_load_weights"):
+        model.after_load_weights(state_dict)
+
+    del state_dict
+
+    # Set is_sdxl_inpaint flag.
+    # Checks Unet structure to detect inpaint model. The inpaint model's
+    # checkpoint state_dict does not contain the key
+    # 'diffusion_model.input_blocks.0.0.weight'.
+    diffusion_model_input = model.model.state_dict().get(
+        'diffusion_model.input_blocks.0.0.weight'
+    )
+    model.is_sdxl_inpaint = (
+        model.is_sdxl and
+        diffusion_model_input is not None and
+        diffusion_model_input.shape[1] == 9
+    )
+
+    if shared.cmd_opts.opt_channelslast:
+        model.to(memory_format=torch.channels_last)
+        timer.record("apply channels_last")
+
+    if shared.cmd_opts.no_half:
+        model.float()
+        model.alphas_cumprod_original = model.alphas_cumprod
+        devices.dtype_unet = torch.float32
+        assert shared.cmd_opts.precision != "half", "Cannot use --precision half with --no-half"
+        timer.record("apply float()")
+    else:
+        vae = model.first_stage_model
+        depth_model = getattr(model, 'depth_model', None)
+
+        # with --no-half-vae, remove VAE from model when doing half() to prevent its weights from being converted to float16
+        if shared.cmd_opts.no_half_vae:
+            model.first_stage_model = None
+        # with --upcast-sampling, don't convert the depth model weights to float16
+        if shared.cmd_opts.upcast_sampling and depth_model:
+            model.depth_model = None
+
+        alphas_cumprod = model.alphas_cumprod
+        model.alphas_cumprod = None
+        if torch.cuda.is_available():
+        model.half()
+        model.alphas_cumprod = alphas_cumprod
+        model.alphas_cumprod_original = alphas_cumprod
+        model.first_stage_model = vae
+        if depth_model:
+            model.depth_model = depth_model
+
+        devices.dtype_unet = torch.float16
+        timer.record("apply half()")
+
+    apply_alpha_schedule_override(model)
+
+    for module in model.modules():
+        if hasattr(module, 'fp16_weight'):
+            del module.fp16_weight
+        if hasattr(module, 'fp16_bias'):
+            del module.fp16_bias
+
+    if check_fp8(model):
+        devices.fp8 = True
+        first_stage = model.first_stage_model
+        model.first_stage_model = None
+        for module in model.modules():
+            if isinstance(module, (torch.nn.Conv2d, torch.nn.Linear)):
+                if shared.opts.cache_fp16_weight:
+                    module.fp16_weight = module.weight.data.clone().cpu().half()
+                    if module.bias is not None:
+                        module.fp16_bias = module.bias.data.clone().cpu().half()
+                module.to(torch.float8_e4m3fn)
+        model.first_stage_model = first_stage
+        timer.record("apply fp8")
+    else:
+        devices.fp8 = False
+
+    devices.unet_needs_upcast = shared.cmd_opts.upcast_sampling and devices.dtype == torch.float16 and devices.dtype_unet == torch.float16
+
+    model.first_stage_model.to(devices.dtype_vae)
+    timer.record("apply dtype to VAE")
+
+    # clean up cache if limit is reached
+    while len(checkpoints_loaded) > shared.opts.sd_checkpoint_cache:
+        checkpoints_loaded.popitem(last=False)
+
+    model.sd_model_hash = sd_model_hash
+    model.sd_model_checkpoint = checkpoint_info.filename
+    model.sd_checkpoint_info = checkpoint_info
+    shared.opts.data["sd_checkpoint_hash"] = checkpoint_info.sha256
+
+    if hasattr(model, 'logvar'):
+        model.logvar = model.logvar.to(devices.device)  # fix for training
+
+    sd_vae.delete_base_vae()
+    sd_vae.clear_loaded_vae()
+    vae_file, vae_source = sd_vae.resolve_vae(checkpoint_info.filename).tuple()
+    sd_vae.load_vae(model, vae_file, vae_source)
+    timer.record("load VAE")
+
+
+def enable_midas_autodownload():
+    """
+    Gives the ldm.modules.midas.api.load_model function automatic downloading.
+
+    When the 512-depth-ema model, and other future models like it, is loaded,
+    it calls midas.api.load_model to load the associated midas depth model.
+    This function applies a wrapper to download the model to the correct
+    location automatically.
+    """
+
+    midas_path = os.path.join(paths.models_path, 'midas')
+
+    # stable-diffusion-stability-ai hard-codes the midas model path to
+    # a location that differs from where other scripts using this model look.
+    # HACK: Overriding the path here.
+    for k, v in midas.api.ISL_PATHS.items():
+        file_name = os.path.basename(v)
+        midas.api.ISL_PATHS[k] = os.path.join(midas_path, file_name)
+
+    midas_urls = {
+        "dpt_large": "https://github.com/intel-isl/DPT/releases/download/1_0/dpt_large-midas-2f21e586.pt",
+        "dpt_hybrid": "https://github.com/intel-isl/DPT/releases/download/1_0/dpt_hybrid-midas-501f0c75.pt",
+        "midas_v21": "https://github.com/AlexeyAB/MiDaS/releases/download/midas_dpt/midas_v21-f6b98070.pt",
+        "midas_v21_small": "https://github.com/AlexeyAB/MiDaS/releases/download/midas_dpt/midas_v21_small-70d6b9c8.pt",
+    }
+
+    midas.api.load_model_inner = midas.api.load_model
+
+    def load_model_wrapper(model_type):
+        path = midas.api.ISL_PATHS[model_type]
+        if not os.path.exists(path):
+            if not os.path.exists(midas_path):
+                os.mkdir(midas_path)
+
+            print(f"Downloading midas model weights for {model_type} to {path}")
+            request.urlretrieve(midas_urls[model_type], path)
+            print(f"{model_type} downloaded")
+
+        return midas.api.load_model_inner(model_type)
+
+    midas.api.load_model = load_model_wrapper
+
+
+def patch_given_betas():
+    import ldm.models.diffusion.ddpm
+
+    def patched_register_schedule(*args, **kwargs):
+        """a modified version of register_schedule function that converts plain list from Omegaconf into numpy"""
+
+        if isinstance(args[1], ListConfig):
+            args = (args[0], np.array(args[1]), *args[2:])
+
+        original_register_schedule(*args, **kwargs)
+
+    original_register_schedule = patches.patch(__name__, ldm.models.diffusion.ddpm.DDPM, 'register_schedule', patched_register_schedule)
+
+
+def repair_config(sd_config, state_dict=None):
+    if not hasattr(sd_config.model.params, "use_ema"):
+        sd_config.model.params.use_ema = False
+
+    if hasattr(sd_config.model.params, 'unet_config'):
+        if shared.cmd_opts.no_half:
+            sd_config.model.params.unet_config.params.use_fp16 = False
+        elif shared.cmd_opts.upcast_sampling or shared.cmd_opts.precision == "half":
+            sd_config.model.params.unet_config.params.use_fp16 = True
+
+    if hasattr(sd_config.model.params, 'first_stage_config'):
+        if getattr(sd_config.model.params.first_stage_config.params.ddconfig, "attn_type", None) == "vanilla-xformers" and not shared.xformers_available:
+            sd_config.model.params.first_stage_config.params.ddconfig.attn_type = "vanilla"
+
+    # For UnCLIP-L, override the hardcoded karlo directory
+    if hasattr(sd_config.model.params, "noise_aug_config") and hasattr(sd_config.model.params.noise_aug_config.params, "clip_stats_path"):
+        karlo_path = os.path.join(paths.models_path, 'karlo')
+        sd_config.model.params.noise_aug_config.params.clip_stats_path = sd_config.model.params.noise_aug_config.params.clip_stats_path.replace("checkpoints/karlo_models", karlo_path)
+
+    # Do not use checkpoint for inference.
+    # This helps prevent extra performance overhead on checking parameters.
+    # The perf overhead is about 100ms/it on 4090 for SDXL.
+    if hasattr(sd_config.model.params, "network_config"):
+        sd_config.model.params.network_config.params.use_checkpoint = False
+    if hasattr(sd_config.model.params, "unet_config"):
+        sd_config.model.params.unet_config.params.use_checkpoint = False
+
+
+
+def rescale_zero_terminal_snr_abar(alphas_cumprod):
+    alphas_bar_sqrt = alphas_cumprod.sqrt()
+
+    # Store old values.
+    alphas_bar_sqrt_0 = alphas_bar_sqrt[0].clone()
+    alphas_bar_sqrt_T = alphas_bar_sqrt[-1].clone()
+
+    # Shift so the last timestep is zero.
+    alphas_bar_sqrt -= (alphas_bar_sqrt_T)
+
+    # Scale so the first timestep is back to the old value.
+    alphas_bar_sqrt *= alphas_bar_sqrt_0 / (alphas_bar_sqrt_0 - alphas_bar_sqrt_T)
+
+    # Convert alphas_bar_sqrt to betas
+    alphas_bar = alphas_bar_sqrt ** 2  # Revert sqrt
+    alphas_bar[-1] = 4.8973451890853435e-08
+    return alphas_bar
+
+
+def apply_alpha_schedule_override(sd_model, p=None):
+    """
+    Applies an override to the alpha schedule of the model according to settings.
+    - downcasts the alpha schedule to half precision
+    - rescales the alpha schedule to have zero terminal SNR
+    """
+
+    if not hasattr(sd_model, 'alphas_cumprod') or not hasattr(sd_model, 'alphas_cumprod_original'):
+        return
+
+    sd_model.alphas_cumprod = sd_model.alphas_cumprod_original.to(shared.device)
+
+    if opts.use_downcasted_alpha_bar:
+        if p is not None:
+            p.extra_generation_params['Downcast alphas_cumprod'] = opts.use_downcasted_alpha_bar
+        sd_model.alphas_cumprod = sd_model.alphas_cumprod.half().to(shared.device)
+
+    if opts.sd_noise_schedule == "Zero Terminal SNR":
+        if p is not None:
+            p.extra_generation_params['Noise Schedule'] = opts.sd_noise_schedule
+        sd_model.alphas_cumprod = rescale_zero_terminal_snr_abar(sd_model.alphas_cumprod).to(shared.device)
+
+
+sd1_clip_weight = 'cond_stage_model.transformer.text_model.embeddings.token_embedding.weight'
+sd2_clip_weight = 'cond_stage_model.model.transformer.resblocks.0.attn.in_proj_weight'
+sdxl_clip_weight = 'conditioner.embedders.1.model.ln_final.weight'
+sdxl_refiner_clip_weight = 'conditioner.embedders.0.model.ln_final.weight'
+
+
+class SdModelData:
+    def __init__(self):
+        self.sd_model = None
+        self.loaded_sd_models = []
+        self.was_loaded_at_least_once = False
+        self.lock = threading.Lock()
+
+    def get_sd_model(self):
+        if self.was_loaded_at_least_once:
+            return self.sd_model
+
+        if self.sd_model is None:
+            with self.lock:
+                if self.sd_model is not None or self.was_loaded_at_least_once:
+                    return self.sd_model
+
+                try:
+                    load_model()
+
+                except Exception as e:
+                    errors.display(e, "loading stable diffusion model", full_traceback=True)
+                    print("", file=sys.stderr)
+                    print("Stable diffusion model failed to load", file=sys.stderr)
+                    self.sd_model = None
+
+        return self.sd_model
+
+    def set_sd_model(self, v, already_loaded=False):
+        self.sd_model = v
+        if already_loaded:
+            sd_vae.base_vae = getattr(v, "base_vae", None)
+            sd_vae.loaded_vae_file = getattr(v, "loaded_vae_file", None)
+            sd_vae.checkpoint_info = v.sd_checkpoint_info
+
+        try:
+            self.loaded_sd_models.remove(v)
+        except ValueError:
+            pass
+
+        if v is not None:
+            self.loaded_sd_models.insert(0, v)
+
+
+model_data = SdModelData()
+
+
+def get_empty_cond(sd_model):
+
+    p = processing.StableDiffusionProcessingTxt2Img()
+    extra_networks.activate(p, {})
+
+    if hasattr(sd_model, 'get_learned_conditioning'):
+        d = sd_model.get_learned_conditioning([""])
+    else:
+        d = sd_model.cond_stage_model([""])
+
+    if isinstance(d, dict):
+        d = d['crossattn']
+
+    return d
+
+
+def send_model_to_cpu(m):
+    if m is not None:
+        if m.lowvram:
+            lowvram.send_everything_to_cpu()
+        else:
+            m.to(devices.cpu)
+
+    devices.torch_gc()
+
+
+def model_target_device(m):
+    if lowvram.is_needed(m):
+        return devices.cpu
+    else:
+        return devices.device
+
+
+def send_model_to_device(m):
+    lowvram.apply(m)
+
+    if not m.lowvram:
+        m.to(shared.device)
+
+
+def send_model_to_trash(m):
+    m.to(device="meta")
+    devices.torch_gc()
+
+
+def instantiate_from_config(config, state_dict=None):
+    constructor = get_obj_from_str(config["target"])
+
+    params = {**config.get("params", {})}
+
+    if state_dict and "state_dict" in params and params["state_dict"] is None:
+        params["state_dict"] = state_dict
+
+    return constructor(**params)
+
+
+def get_obj_from_str(string, reload=False):
+    module, cls = string.rsplit(".", 1)
+    if reload:
+        module_imp = importlib.import_module(module)
+        importlib.reload(module_imp)
+    return getattr(importlib.import_module(module, package=None), cls)
+
+
+def load_model(checkpoint_info=None, already_loaded_state_dict=None):
+    from modules import sd_hijack
+    checkpoint_info = checkpoint_info or select_checkpoint()
+
+    timer = Timer()
+
+    if model_data.sd_model:
+        send_model_to_trash(model_data.sd_model)
+        model_data.sd_model = None
+        devices.torch_gc()
+
+    timer.record("unload existing model")
+
+    if already_loaded_state_dict is not None:
+        state_dict = already_loaded_state_dict
+    else:
+        state_dict = get_checkpoint_state_dict(checkpoint_info, timer)
+
+    checkpoint_config = sd_models_config.find_checkpoint_config(state_dict, checkpoint_info)
+    clip_is_included_into_sd = any(x for x in [sd1_clip_weight, sd2_clip_weight, sdxl_clip_weight, sdxl_refiner_clip_weight] if x in state_dict)
+
+    timer.record("find config")
+
+    sd_config = OmegaConf.load(checkpoint_config)
+    repair_config(sd_config, state_dict)
+
+    timer.record("load config")
+
+    print(f"Creating model from config: {checkpoint_config}")
+
+    sd_model = None
+    try:
+        with sd_disable_initialization.DisableInitialization(disable_clip=clip_is_included_into_sd or shared.cmd_opts.do_not_download_clip):
+            with sd_disable_initialization.InitializeOnMeta():
+                sd_model = instantiate_from_config(sd_config.model, state_dict)
+
+    except Exception as e:
+        errors.display(e, "creating model quickly", full_traceback=True)
+
+    if sd_model is None:
+        print('Failed to create model quickly; will retry using slow method.', file=sys.stderr)
+
+        with sd_disable_initialization.InitializeOnMeta():
+            sd_model = instantiate_from_config(sd_config.model, state_dict)
+
+    sd_model.used_config = checkpoint_config
+
+    timer.record("create model")
+
+    if shared.cmd_opts.no_half:
+        weight_dtype_conversion = None
+    else:
+        weight_dtype_conversion = {
+            'first_stage_model': None,
+            'alphas_cumprod': None,
+            '': torch.float16,
+        }
+
+    with sd_disable_initialization.LoadStateDictOnMeta(state_dict, device=model_target_device(sd_model), weight_dtype_conversion=weight_dtype_conversion):
+        load_model_weights(sd_model, checkpoint_info, state_dict, timer)
+
+    timer.record("load weights from state dict")
+
+    send_model_to_device(sd_model)
+    timer.record("move model to device")
+
+    sd_hijack.model_hijack.hijack(sd_model)
+
+    timer.record("hijack")
+
+    sd_model.eval()
+    model_data.set_sd_model(sd_model)
+    model_data.was_loaded_at_least_once = True
+
+    sd_hijack.model_hijack.embedding_db.load_textual_inversion_embeddings(force_reload=True)  # Reload embeddings after model load as they may or may not fit the model
+
+    timer.record("load textual inversion embeddings")
+
+    script_callbacks.model_loaded_callback(sd_model)
+
+    timer.record("scripts callbacks")
+
+    with devices.autocast(), torch.no_grad():
+        sd_model.cond_stage_model_empty_prompt = get_empty_cond(sd_model)
+
+    timer.record("calculate empty prompt")
+
+    print(f"Model loaded in {timer.summary()}.")
+
+    return sd_model
+
+
+def reuse_model_from_already_loaded(sd_model, checkpoint_info, timer):
+    """
+    Checks if the desired checkpoint from checkpoint_info is not already loaded in model_data.loaded_sd_models.
+    If it is loaded, returns that (moving it to GPU if necessary, and moving the currently loadded model to CPU if necessary).
+    If not, returns the model that can be used to load weights from checkpoint_info's file.
+    If no such model exists, returns None.
+    Additionally deletes loaded models that are over the limit set in settings (sd_checkpoints_limit).
+    """
+
+    if sd_model is not None and sd_model.sd_checkpoint_info.filename == checkpoint_info.filename:
+        return sd_model
+
+    if shared.opts.sd_checkpoints_keep_in_cpu:
+        send_model_to_cpu(sd_model)
+        timer.record("send model to cpu")
+
+    already_loaded = None
+    for i in reversed(range(len(model_data.loaded_sd_models))):
+        loaded_model = model_data.loaded_sd_models[i]
+        if loaded_model.sd_checkpoint_info.filename == checkpoint_info.filename:
+            already_loaded = loaded_model
+            continue
+
+        if len(model_data.loaded_sd_models) > shared.opts.sd_checkpoints_limit > 0:
+            print(f"Unloading model {len(model_data.loaded_sd_models)} over the limit of {shared.opts.sd_checkpoints_limit}: {loaded_model.sd_checkpoint_info.title}")
+            del model_data.loaded_sd_models[i]
+            send_model_to_trash(loaded_model)
+            timer.record("send model to trash")
+
+    if already_loaded is not None:
+        send_model_to_device(already_loaded)
+        timer.record("send model to device")
+
+        model_data.set_sd_model(already_loaded, already_loaded=True)
+
+        if not SkipWritingToConfig.skip:
+            shared.opts.data["sd_model_checkpoint"] = already_loaded.sd_checkpoint_info.title
+            shared.opts.data["sd_checkpoint_hash"] = already_loaded.sd_checkpoint_info.sha256
+
+        print(f"Using already loaded model {already_loaded.sd_checkpoint_info.title}: done in {timer.summary()}")
+        sd_vae.reload_vae_weights(already_loaded)
+        return model_data.sd_model
+    elif shared.opts.sd_checkpoints_limit > 1 and len(model_data.loaded_sd_models) < shared.opts.sd_checkpoints_limit:
+        print(f"Loading model {checkpoint_info.title} ({len(model_data.loaded_sd_models) + 1} out of {shared.opts.sd_checkpoints_limit})")
+
+        model_data.sd_model = None
+        load_model(checkpoint_info)
+        return model_data.sd_model
+    elif len(model_data.loaded_sd_models) > 0:
+        sd_model = model_data.loaded_sd_models.pop()
+        model_data.sd_model = sd_model
+
+        sd_vae.base_vae = getattr(sd_model, "base_vae", None)
+        sd_vae.loaded_vae_file = getattr(sd_model, "loaded_vae_file", None)
+        sd_vae.checkpoint_info = sd_model.sd_checkpoint_info
+
+        print(f"Reusing loaded model {sd_model.sd_checkpoint_info.title} to load {checkpoint_info.title}")
+        return sd_model
+    else:
+        return None
+
+
+def reload_model_weights(sd_model=None, info=None, forced_reload=False):
+    checkpoint_info = info or select_checkpoint()
+
+    timer = Timer()
+
+    if not sd_model:
+        sd_model = model_data.sd_model
+
+    if sd_model is None:  # previous model load failed
+        current_checkpoint_info = None
+    else:
+        current_checkpoint_info = sd_model.sd_checkpoint_info
+        if check_fp8(sd_model) != devices.fp8:
+            # load from state dict again to prevent extra numerical errors
+            forced_reload = True
+        elif sd_model.sd_model_checkpoint == checkpoint_info.filename and not forced_reload:
+            return sd_model
+
+    sd_model = reuse_model_from_already_loaded(sd_model, checkpoint_info, timer)
+    if not forced_reload and sd_model is not None and sd_model.sd_checkpoint_info.filename == checkpoint_info.filename:
+        return sd_model
+
+    if sd_model is not None:
+        sd_unet.apply_unet("None")
+        send_model_to_cpu(sd_model)
+        sd_hijack.model_hijack.undo_hijack(sd_model)
+
+    state_dict = get_checkpoint_state_dict(checkpoint_info, timer)
+
+    checkpoint_config = sd_models_config.find_checkpoint_config(state_dict, checkpoint_info)
+
+    timer.record("find config")
+
+    if sd_model is None or checkpoint_config != sd_model.used_config:
+        if sd_model is not None:
+            send_model_to_trash(sd_model)
+
+        load_model(checkpoint_info, already_loaded_state_dict=state_dict)
+        return model_data.sd_model
+
+    try:
+        load_model_weights(sd_model, checkpoint_info, state_dict, timer)
+    except Exception:
+        print("Failed to load checkpoint, restoring previous")
+        load_model_weights(sd_model, current_checkpoint_info, None, timer)
+        raise
+    finally:
+        sd_hijack.model_hijack.hijack(sd_model)
+        timer.record("hijack")
+
+        if not sd_model.lowvram:
+            sd_model.to(devices.device)
+            timer.record("move model to device")
+
+        script_callbacks.model_loaded_callback(sd_model)
+        timer.record("script callbacks")
+
+    print(f"Weights loaded in {timer.summary()}.")
+
+    model_data.set_sd_model(sd_model)
+    sd_unet.apply_unet()
+
+    return sd_model
+
+
+def unload_model_weights(sd_model=None, info=None):
+    send_model_to_cpu(sd_model or shared.sd_model)
+
+    return sd_model
+
+
+def apply_token_merging(sd_model, token_merging_ratio):
+    """
+    Applies speed and memory optimizations from tomesd.
+    """
+
+    current_token_merging_ratio = getattr(sd_model, 'applied_token_merged_ratio', 0)
+
+    if current_token_merging_ratio == token_merging_ratio:
+        return
+
+    if current_token_merging_ratio > 0:
+        tomesd.remove_patch(sd_model)
+
+    if token_merging_ratio > 0:
+        tomesd.apply_patch(
+            sd_model,
+            ratio=token_merging_ratio,
+            use_rand=False,  # can cause issues with some samplers
+            merge_attn=True,
+            merge_crossattn=False,
+            merge_mlp=False
+        )
+
+    sd_model.applied_token_merged_ratio = token_merging_ratio