From 7ccd4614a56cfd6ecacba85605f338593f1059f0 Mon Sep 17 00:00:00 2001
From: Volpeon <git@volpeon.ink>
Date: Tue, 7 Feb 2023 20:44:43 +0100
Subject: Add Lora

---
 training/strategy/lora.py | 147 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 147 insertions(+)
 create mode 100644 training/strategy/lora.py

(limited to 'training/strategy/lora.py')

diff --git a/training/strategy/lora.py b/training/strategy/lora.py
new file mode 100644
index 0000000..88d1824
--- /dev/null
+++ b/training/strategy/lora.py
@@ -0,0 +1,147 @@
+from contextlib import nullcontext
+from typing import Optional
+from functools import partial
+from contextlib import contextmanager, nullcontext
+from pathlib import Path
+
+import torch
+import torch.nn as nn
+from torch.utils.data import DataLoader
+
+from accelerate import Accelerator
+from transformers import CLIPTextModel
+from diffusers import AutoencoderKL, UNet2DConditionModel, DPMSolverMultistepScheduler
+from diffusers.loaders import AttnProcsLayers
+
+from slugify import slugify
+
+from models.clip.tokenizer import MultiCLIPTokenizer
+from training.util import EMAModel
+from training.functional import TrainingStrategy, TrainingCallbacks, save_samples
+
+
+def lora_strategy_callbacks(
+    accelerator: Accelerator,
+    unet: UNet2DConditionModel,
+    text_encoder: CLIPTextModel,
+    tokenizer: MultiCLIPTokenizer,
+    vae: AutoencoderKL,
+    sample_scheduler: DPMSolverMultistepScheduler,
+    train_dataloader: DataLoader,
+    val_dataloader: Optional[DataLoader],
+    sample_output_dir: Path,
+    checkpoint_output_dir: Path,
+    seed: int,
+    lora_layers: AttnProcsLayers,
+    max_grad_norm: float = 1.0,
+    sample_batch_size: int = 1,
+    sample_num_batches: int = 1,
+    sample_num_steps: int = 20,
+    sample_guidance_scale: float = 7.5,
+    sample_image_size: Optional[int] = None,
+):
+    sample_output_dir.mkdir(parents=True, exist_ok=True)
+    checkpoint_output_dir.mkdir(parents=True, exist_ok=True)
+
+    weight_dtype = torch.float32
+    if accelerator.state.mixed_precision == "fp16":
+        weight_dtype = torch.float16
+    elif accelerator.state.mixed_precision == "bf16":
+        weight_dtype = torch.bfloat16
+
+    save_samples_ = partial(
+        save_samples,
+        accelerator=accelerator,
+        unet=unet,
+        text_encoder=text_encoder,
+        tokenizer=tokenizer,
+        vae=vae,
+        sample_scheduler=sample_scheduler,
+        train_dataloader=train_dataloader,
+        val_dataloader=val_dataloader,
+        output_dir=sample_output_dir,
+        seed=seed,
+        batch_size=sample_batch_size,
+        num_batches=sample_num_batches,
+        num_steps=sample_num_steps,
+        guidance_scale=sample_guidance_scale,
+        image_size=sample_image_size,
+    )
+
+    def on_prepare():
+        lora_layers.requires_grad_(True)
+
+    def on_accum_model():
+        return unet
+
+    @contextmanager
+    def on_train(epoch: int):
+        tokenizer.train()
+        yield
+
+    @contextmanager
+    def on_eval():
+        tokenizer.eval()
+        yield
+
+    def on_before_optimize(lr: float, epoch: int):
+        if accelerator.sync_gradients:
+            accelerator.clip_grad_norm_(lora_layers.parameters(), max_grad_norm)
+
+    @torch.no_grad()
+    def on_checkpoint(step, postfix):
+        print(f"Saving checkpoint for step {step}...")
+        orig_unet_dtype = unet.dtype
+        unet.to(dtype=torch.float32)
+        unet.save_attn_procs(checkpoint_output_dir.joinpath(f"{step}_{postfix}"))
+        unet.to(dtype=orig_unet_dtype)
+
+    @torch.no_grad()
+    def on_sample(step):
+        orig_unet_dtype = unet.dtype
+        unet.to(dtype=weight_dtype)
+        save_samples_(step=step)
+        unet.to(dtype=orig_unet_dtype)
+
+        if torch.cuda.is_available():
+            torch.cuda.empty_cache()
+
+    return TrainingCallbacks(
+        on_prepare=on_prepare,
+        on_accum_model=on_accum_model,
+        on_train=on_train,
+        on_eval=on_eval,
+        on_before_optimize=on_before_optimize,
+        on_checkpoint=on_checkpoint,
+        on_sample=on_sample,
+    )
+
+
+def lora_prepare(
+    accelerator: Accelerator,
+    text_encoder: CLIPTextModel,
+    unet: UNet2DConditionModel,
+    optimizer: torch.optim.Optimizer,
+    train_dataloader: DataLoader,
+    val_dataloader: Optional[DataLoader],
+    lr_scheduler: torch.optim.lr_scheduler._LRScheduler,
+    lora_layers: AttnProcsLayers,
+    **kwargs
+):
+    weight_dtype = torch.float32
+    if accelerator.state.mixed_precision == "fp16":
+        weight_dtype = torch.float16
+    elif accelerator.state.mixed_precision == "bf16":
+        weight_dtype = torch.bfloat16
+
+    lora_layers, optimizer, train_dataloader, val_dataloader, lr_scheduler = accelerator.prepare(
+        lora_layers, optimizer, train_dataloader, val_dataloader, lr_scheduler)
+    unet.to(accelerator.device, dtype=weight_dtype)
+    text_encoder.to(accelerator.device, dtype=weight_dtype)
+    return text_encoder, unet, optimizer, train_dataloader, val_dataloader, lr_scheduler, {"lora_layers": lora_layers}
+
+
+lora_strategy = TrainingStrategy(
+    callbacks=lora_strategy_callbacks,
+    prepare=lora_prepare,
+)
-- 
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