Files

559 lines
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Python

import os
import types
from typing import List, Optional
import huggingface_hub
import torch
import torch.utils.checkpoint
import yaml
from toolkit.config_modules import GenerateImageConfig, ModelConfig, NetworkConfig
from toolkit.lora_special import LoRASpecialNetwork
from toolkit.models.base_model import BaseModel
from toolkit.basic import flush
from toolkit.prompt_utils import PromptEmbeds
from toolkit.samplers.custom_flowmatch_sampler import (
CustomFlowMatchEulerDiscreteScheduler,
)
from toolkit.accelerator import unwrap_model
from optimum.quanto import freeze
from toolkit.util.quantize import quantize, get_qtype, quantize_model
from toolkit.memory_management import MemoryManager
from safetensors.torch import load_file
from transformers import AutoTokenizer, Qwen3ForCausalLM
from diffusers import AutoencoderKL
try:
from diffusers import ZImagePipeline
from diffusers.models.transformers import ZImageTransformer2DModel
except ImportError:
raise ImportError(
"Diffusers is out of date. Update diffusers to the latest version."
)
scheduler_config = {
"num_train_timesteps": 1000,
"use_dynamic_shifting": False,
"shift": 3.0,
}
# --- SURGICAL TOOL: MONKEY PATCH ---
# Prevents AI Toolkit from crashing when it tries to set requires_grad=True
# on quantized (integer) weights.
def safe_requires_grad_(self, requires_grad=True):
for param in self.parameters():
if param.dtype.is_floating_point:
param.requires_grad = requires_grad
return self
class ZImageModel(BaseModel):
arch = "zimage"
def __init__(
self,
device,
model_config: ModelConfig,
dtype="bf16",
custom_pipeline=None,
noise_scheduler=None,
**kwargs,
):
super().__init__(
device, model_config, dtype, custom_pipeline, noise_scheduler, **kwargs
)
self.is_flow_matching = True
self.is_transformer = True
self.target_lora_modules = ["ZImageTransformer2DModel", "Qwen3ForCausalLM", "Qwen2ForCausalLM"]
@staticmethod
def get_train_scheduler():
return CustomFlowMatchEulerDiscreteScheduler(**scheduler_config)
def get_bucket_divisibility(self):
return 16 * 2
def load_training_adapter(self, transformer: ZImageTransformer2DModel):
self.print_and_status_update("Loading assistant LoRA")
lora_path = self.model_config.assistant_lora_path
if not os.path.exists(lora_path):
lora_splits = lora_path.split("/")
if len(lora_splits) != 3:
raise ValueError(f"Invalid LoRA path: {lora_path}")
repo_id = "/".join(lora_splits[:2])
filename = lora_splits[2]
try:
lora_path = huggingface_hub.hf_hub_download(repo_id=repo_id, filename=filename)
self.model_config.assistant_lora_path = lora_path
except Exception as e:
raise ValueError(f"Failed to download assistant LoRA: {e}")
lora_state_dict = load_file(lora_path)
dim = int(lora_state_dict["diffusion_model.layers.0.attention.to_k.lora_A.weight"].shape[0])
new_sd = {}
for key, value in lora_state_dict.items():
new_key = key.replace("diffusion_model.", "transformer.")
new_sd[new_key] = value
lora_state_dict = new_sd
network_config = NetworkConfig(type="lora", linear=dim, linear_alpha=dim, transformer_only=True)
LoRASpecialNetwork.LORA_PREFIX_UNET = "lora_transformer"
network = LoRASpecialNetwork(
text_encoder=None,
unet=transformer,
lora_dim=network_config.linear,
multiplier=1.0,
alpha=network_config.linear_alpha,
train_unet=True,
train_text_encoder=False,
network_config=network_config,
network_type=network_config.type,
transformer_only=network_config.transformer_only,
is_transformer=True,
target_lin_modules=self.target_lora_modules,
is_assistant_adapter=True,
is_ara=True,
)
network.apply_to(None, transformer, apply_text_encoder=False, apply_unet=True)
self.print_and_status_update("Merging in assistant LoRA")
network.force_to(transformer.device, dtype=self.torch_dtype)
network._update_torch_multiplier()
network.load_weights(lora_state_dict)
network.merge_in(merge_weight=1.0)
network.is_merged_in = False
self.assistant_lora = network
self.assistant_lora.multiplier = -1.0
self.assistant_lora.is_active = False
self.invert_assistant_lora = True
def load_model(self):
dtype = self.torch_dtype
self.print_and_status_update("Loading ZImage model")
model_path = self.model_config.name_or_path
base_model_path = self.model_config.extras_name_or_path
self.print_and_status_update("Loading transformer")
transformer_path = model_path
transformer_subfolder = "transformer"
if os.path.exists(transformer_path):
transformer_subfolder = None
transformer_path = os.path.join(transformer_path, "transformer")
te_folder_path = os.path.join(model_path, "text_encoder")
if os.path.exists(te_folder_path):
base_model_path = model_path
# 1. Load Transformer
transformer = ZImageTransformer2DModel.from_pretrained(
transformer_path,
subfolder=transformer_subfolder,
torch_dtype=dtype,
low_cpu_mem_usage=False,
ignore_mismatched_sizes=True
)
if self.model_config.assistant_lora_path is not None:
self.load_training_adapter(transformer)
# --- SURGICAL MODIFICATION: QUANTIZATION (QUANTO) ---
should_quantize_transformer = self.model_config.quantize or (
self.model_config.low_vram and not self.model_config.train_unet
)
if should_quantize_transformer:
if self.model_config.qtype == "qfloat8":
self.model_config.qtype = "float8"
self.print_and_status_update(f"Surgical Plan: Quantizing Transformer (Quanto)")
transformer.requires_grad_(False)
# Monkey Patch BEFORE quantize
transformer.requires_grad_ = types.MethodType(safe_requires_grad_, transformer)
quantize_model(self, transformer)
flush()
# --- FIX: TROJAN HORSE PARAMETER ---
transformer.dummy_param = torch.nn.Parameter(torch.zeros(1, dtype=dtype, device=self.device_torch))
transformer.dummy_param.requires_grad = True
# Enable input grads (backup mechanism)
if hasattr(transformer, "enable_input_require_grads"):
transformer.enable_input_require_grads()
else:
def make_inputs_require_grad(module, input, output):
output.requires_grad_(True)
if hasattr(transformer, "patch_embed"):
transformer.patch_embed.register_forward_hook(make_inputs_require_grad)
elif hasattr(transformer, "pos_embed"):
transformer.pos_embed.register_forward_hook(make_inputs_require_grad)
if (self.model_config.layer_offloading and self.model_config.layer_offloading_transformer_percent > 0):
MemoryManager.attach(
transformer,
self.device_torch,
offload_percent=self.model_config.layer_offloading_transformer_percent,
ignore_modules=[transformer.x_pad_token, transformer.cap_pad_token]
)
# --- SURGICAL FIX: RESIDENCY ---
train_te = getattr(self.model_config, 'train_text_encoder', False)
if self.model_config.low_vram and not train_te:
self.print_and_status_update("Moving transformer to CPU")
transformer.to("cpu")
else:
self.print_and_status_update("Surgical Plan: Keeping Transformer on GPU for Gradient Flow")
transformer.to(self.device_torch)
flush()
self.print_and_status_update("Text Encoder")
tokenizer = AutoTokenizer.from_pretrained(
base_model_path, subfolder="tokenizer", torch_dtype=dtype
)
text_encoder = Qwen3ForCausalLM.from_pretrained(
base_model_path, subfolder="text_encoder", torch_dtype=dtype
)
if (self.model_config.layer_offloading and self.model_config.layer_offloading_text_encoder_percent > 0):
MemoryManager.attach(
text_encoder,
self.device_torch,
offload_percent=self.model_config.layer_offloading_text_encoder_percent,
)
# --- SURGICAL MODIFICATION: TEXT ENCODER HANDLING ---
if train_te:
self.print_and_status_update("Surgical Plan: Text Encoder Training Active - Preserving BF16")
text_encoder.to(self.device_torch, dtype=dtype)
text_encoder.requires_grad_(False)
if hasattr(text_encoder, "config"):
text_encoder.config.use_cache = False
self.print_and_status_update("Enabling Gradient Checkpointing for Text Encoder")
text_encoder.gradient_checkpointing_enable()
if hasattr(text_encoder, "enable_input_require_grads"):
text_encoder.enable_input_require_grads()
text_encoder.train()
else:
text_encoder.to(self.device_torch, dtype=dtype)
if self.model_config.quantize_te:
self.print_and_status_update("Quantizing Text Encoder")
quantize(text_encoder, weights=get_qtype(self.model_config.qtype_te))
freeze(text_encoder)
flush()
self.print_and_status_update("Loading VAE")
vae = AutoencoderKL.from_pretrained(
base_model_path, subfolder="vae", torch_dtype=dtype
)
self.noise_scheduler = ZImageModel.get_train_scheduler()
self.print_and_status_update("Making pipe")
kwargs = {} # Fixed kwargs error
pipe: ZImagePipeline = ZImagePipeline(
scheduler=self.noise_scheduler,
text_encoder=None,
tokenizer=tokenizer,
vae=vae,
transformer=None,
**kwargs,
)
pipe.text_encoder = text_encoder
pipe.transformer = transformer
self.print_and_status_update("Preparing Model")
text_encoder = [pipe.text_encoder]
tokenizer = [pipe.tokenizer]
if not self.low_vram:
pipe.transformer = pipe.transformer.to(self.device_torch)
flush()
text_encoder[0].to(self.device_torch)
if not train_te:
text_encoder[0].requires_grad_(False)
text_encoder[0].eval()
flush()
self.vae = vae
self.text_encoder = text_encoder
self.tokenizer = tokenizer
self.model = pipe.transformer
# --- FIX: Alias UNet for BaseModel compatibility ---
self.unet = self.model
self.pipeline = pipe
self.print_and_status_update("Model Loaded")
# --- SURGICAL FIX: Custom Device State Handler ---
def set_device_state(self, state):
# Helper to get attributes safe for dict or object
def get_state_attr(obj, name, default=None):
if isinstance(obj, dict):
return obj.get(name, default)
return getattr(obj, name, default)
target_device = get_state_attr(state, 'device')
if self.text_encoder is not None:
if isinstance(self.text_encoder, list):
for te in self.text_encoder:
te.to(target_device)
else:
self.text_encoder.to(target_device)
if self.vae is not None:
self.vae.to(target_device)
if self.transformer is not None:
self.transformer.to(target_device)
should_train_unet = get_state_attr(state, 'train_unet', False)
require_grads = get_state_attr(state, 'require_grads', False)
if should_train_unet:
self.transformer.train()
else:
self.transformer.eval()
# Force train mode if using checkpointing for TE training
if getattr(self.model_config, 'train_text_encoder', False):
self.transformer.train()
# Apply grads SAFELY using monkey patched logic logic if needed,
# or manual check here
target_grad = should_train_unet or require_grads
for param in self.transformer.parameters():
if param.dtype.is_floating_point:
param.requires_grad_(target_grad)
else:
param.requires_grad_(False)
def get_generation_pipeline(self):
scheduler = ZImageModel.get_train_scheduler()
pipeline: ZImagePipeline = ZImagePipeline(
scheduler=scheduler,
text_encoder=unwrap_model(self.text_encoder[0]),
tokenizer=self.tokenizer[0],
vae=unwrap_model(self.vae),
transformer=unwrap_model(self.transformer),
)
pipeline = pipeline.to(self.device_torch)
return pipeline
def generate_single_image(
self,
pipeline: ZImagePipeline,
gen_config: GenerateImageConfig,
conditional_embeds: PromptEmbeds,
unconditional_embeds: PromptEmbeds,
generator: torch.Generator,
extra: dict,
):
self.model.to(self.device_torch, dtype=self.torch_dtype)
self.model.to(self.device_torch)
sc = self.get_bucket_divisibility()
gen_config.width = int(gen_config.width // sc * sc)
gen_config.height = int(gen_config.height // sc * sc)
img = pipeline(
prompt_embeds=conditional_embeds.text_embeds,
negative_prompt_embeds=unconditional_embeds.text_embeds,
height=gen_config.height,
width=gen_config.width,
num_inference_steps=gen_config.num_inference_steps,
guidance_scale=gen_config.guidance_scale,
latents=gen_config.latents,
generator=generator,
**extra,
).images[0]
return img
def get_noise_prediction(
self,
latent_model_input: torch.Tensor,
timestep: torch.Tensor,
text_embeddings: PromptEmbeds,
**kwargs,
):
self.model.to(self.device_torch)
self.transformer.train() # Force train for checkpointing
# --- SURGICAL FIX: Jumper Cable (External Checkpointing) ---
# 1. Prepare Inputs (Must require grad)
latent_model_input.requires_grad_(True)
timestep_model_input = (1000 - timestep) / 1000
encoder_hidden_states = text_embeddings.text_embeds
if isinstance(encoder_hidden_states, list):
encoder_hidden_states = encoder_hidden_states[0]
text_embeddings.text_embeds = encoder_hidden_states
# FIX: Ensure 3D (Batch, Seq, Dim)
if torch.is_tensor(encoder_hidden_states):
if encoder_hidden_states.ndim == 2:
encoder_hidden_states = encoder_hidden_states.unsqueeze(0)
encoder_hidden_states.requires_grad_(True)
# 2. Define Wrapper (Handles unpacking for Z-Image)
def _forward_wrapper(latents_batch, t_batch, encoder_hidden_batch):
# Unpack Latents: (B, C, H, W) -> List[(C, 1, H, W)]
latents_list = list(latents_batch.unsqueeze(2).unbind(0))
# Unpack Embeds: (B, Seq, Dim) -> List[(Seq, Dim)]
# Fixes "1 and 2" dimensions error by strictly providing 2D tensors
encoder_list = list(encoder_hidden_batch.unbind(0))
# Run Transformer (Black Box)
output = self.transformer(latents_list, t_batch, encoder_list)
# Repack: List[Tensor] -> Tensor
return torch.stack([t.float() for t in output[0]], dim=0)
# 3. Execute via Jumper Cable
noise_pred = torch.utils.checkpoint.checkpoint(
_forward_wrapper,
latent_model_input,
timestep_model_input,
encoder_hidden_states,
use_reentrant=False
)
noise_pred = noise_pred.squeeze(2)
noise_pred = -noise_pred
# --- SURGICAL FIX: TROJAN HORSE CONNECTION ---
if hasattr(self.transformer, "dummy_param"):
if self.transformer.dummy_param.device != noise_pred.device:
self.transformer.dummy_param.data = self.transformer.dummy_param.data.to(noise_pred.device)
loss_proxy = self.transformer.dummy_param.sum() * 0
noise_pred = noise_pred + loss_proxy
return noise_pred
def get_prompt_embeds(self, prompt: str) -> PromptEmbeds:
# SURGICAL FIX: Manual Pipeline Bypass & Direct Input Injection
train_te = getattr(self.model_config, 'train_text_encoder', False)
if not train_te:
if self.pipeline.text_encoder.device != self.device_torch:
self.pipeline.text_encoder.to(self.device_torch)
prompt_embeds, _ = self.pipeline.encode_prompt(
prompt,
do_classifier_free_guidance=False,
device=self.device_torch,
)
return PromptEmbeds([prompt_embeds, None])
tokenizer = self.tokenizer[0] if isinstance(self.tokenizer, list) else self.tokenizer
text_encoder = self.text_encoder[0] if isinstance(self.text_encoder, list) else self.text_encoder
text_encoder.to(self.device_torch)
if isinstance(prompt, str):
prompt = [prompt]
max_len = getattr(tokenizer, 'model_max_length', 512)
if max_len > 1024: max_len = 512
text_inputs = tokenizer(
prompt,
padding="max_length",
max_length=max_len,
truncation=True,
return_tensors="pt",
).to(self.device_torch)
# Direct Injection Logic
with torch.set_grad_enabled(True):
input_embed_layer = text_encoder.get_input_embeddings()
inputs_embeds = input_embed_layer(text_inputs.input_ids)
inputs_embeds.requires_grad_(True)
outputs = text_encoder(
inputs_embeds=inputs_embeds,
attention_mask=text_inputs.attention_mask,
output_hidden_states=True
)
if hasattr(outputs, "hidden_states"):
prompt_embeds = outputs.hidden_states[-1]
else:
prompt_embeds = outputs[0]
# FORCE 3D SHAPE (Batch, Seq, Dim)
if prompt_embeds.ndim == 2:
prompt_embeds = prompt_embeds.unsqueeze(0)
return PromptEmbeds([prompt_embeds, None])
def get_model_has_grad(self):
if self.model is None:
return False
return any(p.requires_grad for p in self.model.parameters())
def get_te_has_grad(self):
if self.text_encoder is None:
return False
te0 = self.text_encoder[0] if isinstance(self.text_encoder, list) else self.text_encoder
return any(p.requires_grad for p in te0.parameters())
def save_model(self, output_path, meta, save_dtype):
transformer: ZImageTransformer2DModel = unwrap_model(self.model)
transformer.save_pretrained(
save_directory=os.path.join(output_path, "transformer"),
safe_serialization=True,
)
if self.get_te_has_grad():
te0 = self.text_encoder[0] if isinstance(self.text_encoder, list) else self.text_encoder
te0 = unwrap_model(te0)
te0.save_pretrained(
save_directory=os.path.join(output_path, "text_encoder"),
safe_serialization=True,
)
tok0 = self.tokenizer[0] if isinstance(self.tokenizer, list) else self.tokenizer
tok0.save_pretrained(os.path.join(output_path, "tokenizer"))
meta_path = os.path.join(output_path, "aitk_meta.yaml")
with open(meta_path, "w") as f:
yaml.dump(meta, f)
def get_loss_target(self, *args, **kwargs):
noise = kwargs.get("noise")
batch = kwargs.get("batch")
return (noise - batch.latents).detach()
def get_base_model_version(self):
return "zimage"
def get_transformer_block_names(self) -> Optional[List[str]]:
return ["layers"]
def convert_lora_weights_before_save(self, state_dict):
new_sd = {}
for key, value in state_dict.items():
new_key = key.replace("transformer.", "diffusion_model.")
new_sd[new_key] = value
return new_sd
def convert_lora_weights_before_load(self, state_dict):
new_sd = {}
for key, value in state_dict.items():
new_key = key.replace("diffusion_model.", "transformer.")
new_sd[new_key] = value
return new_sd