ComfyUI/comfy/model_detection.py

from . import supported_models

def count_blocks(state_dict_keys, prefix_string):
    count = 0
    while True:
        c = False
        for k in state_dict_keys:
            if k.startswith(prefix_string.format(count)):
                c = True
                break
        if c == False:
            break
        count += 1
    return count

def detect_unet_config(state_dict, key_prefix, use_fp16):
    state_dict_keys = list(state_dict.keys())

    unet_config = {
        "use_checkpoint": False,
        "image_size": 32,
        "out_channels": 4,
        "use_spatial_transformer": True,
        "legacy": False
    }

    y_input = '{}label_emb.0.0.weight'.format(key_prefix)
    if y_input in state_dict_keys:
        unet_config["num_classes"] = "sequential"
        unet_config["adm_in_channels"] = state_dict[y_input].shape[1]
    else:
        unet_config["adm_in_channels"] = None

    unet_config["use_fp16"] = use_fp16
    model_channels = state_dict['{}input_blocks.0.0.weight'.format(key_prefix)].shape[0]
    in_channels = state_dict['{}input_blocks.0.0.weight'.format(key_prefix)].shape[1]

    num_res_blocks = []
    channel_mult = []
    attention_resolutions = []
    transformer_depth = []
    context_dim = None
    use_linear_in_transformer = False


    current_res = 1
    count = 0

    last_res_blocks = 0
    last_transformer_depth = 0
    last_channel_mult = 0

    while True:
        prefix = '{}input_blocks.{}.'.format(key_prefix, count)
        block_keys = sorted(list(filter(lambda a: a.startswith(prefix), state_dict_keys)))
        if len(block_keys) == 0:
            break

        if "{}0.op.weight".format(prefix) in block_keys: #new layer
            if last_transformer_depth > 0:
                attention_resolutions.append(current_res)
            transformer_depth.append(last_transformer_depth)
            num_res_blocks.append(last_res_blocks)
            channel_mult.append(last_channel_mult)

            current_res *= 2
            last_res_blocks = 0
            last_transformer_depth = 0
            last_channel_mult = 0
        else:
            res_block_prefix = "{}0.in_layers.0.weight".format(prefix)
            if res_block_prefix in block_keys:
                last_res_blocks += 1
                last_channel_mult = state_dict["{}0.out_layers.3.weight".format(prefix)].shape[0] // model_channels

            transformer_prefix = prefix + "1.transformer_blocks."
            transformer_keys = sorted(list(filter(lambda a: a.startswith(transformer_prefix), state_dict_keys)))
            if len(transformer_keys) > 0:
                last_transformer_depth = count_blocks(state_dict_keys, transformer_prefix + '{}')
                if context_dim is None:
                    context_dim = state_dict['{}0.attn2.to_k.weight'.format(transformer_prefix)].shape[1]
                    use_linear_in_transformer = len(state_dict['{}1.proj_in.weight'.format(prefix)].shape) == 2

        count += 1

    if last_transformer_depth > 0:
        attention_resolutions.append(current_res)
    transformer_depth.append(last_transformer_depth)
    num_res_blocks.append(last_res_blocks)
    channel_mult.append(last_channel_mult)
    transformer_depth_middle = count_blocks(state_dict_keys, '{}middle_block.1.transformer_blocks.'.format(key_prefix) + '{}')

    if len(set(num_res_blocks)) == 1:
        num_res_blocks = num_res_blocks[0]

    if len(set(transformer_depth)) == 1:
        transformer_depth = transformer_depth[0]

    unet_config["in_channels"] = in_channels
    unet_config["model_channels"] = model_channels
    unet_config["num_res_blocks"] = num_res_blocks
    unet_config["attention_resolutions"] = attention_resolutions
    unet_config["transformer_depth"] = transformer_depth
    unet_config["channel_mult"] = channel_mult
    unet_config["transformer_depth_middle"] = transformer_depth_middle
    unet_config['use_linear_in_transformer'] = use_linear_in_transformer
    unet_config["context_dim"] = context_dim
    return unet_config

def model_config_from_unet_config(unet_config):
    for model_config in supported_models.models:
        if model_config.matches(unet_config):
            return model_config(unet_config)

    return None

def model_config_from_unet(state_dict, unet_key_prefix, use_fp16):
    unet_config = detect_unet_config(state_dict, unet_key_prefix, use_fp16)
    return model_config_from_unet_config(unet_config)