model_cache: add ability to load a diffusers model pipeline

and update associated things in Generate & Generator to not instantly fail when that happens

ldm/generate.py

@@ -18,6 +18,8 @@ import gc
 import hashlib
 import cv2
 import skimage
+from diffusers import DiffusionPipeline, DDIMScheduler, LMSDiscreteScheduler, EulerDiscreteScheduler, \
+    EulerAncestralDiscreteScheduler
 
 from omegaconf import OmegaConf
 from ldm.invoke.generator.base import downsampling
@@ -402,7 +404,10 @@ class Generate:
         width = width or self.width
         height = height or self.height
 
-        configure_model_padding(model, seamless, seamless_axes)
+        if isinstance(model, DiffusionPipeline):
+            configure_model_padding(model.unet, seamless, seamless_axes)
+        else:
+            configure_model_padding(model, seamless, seamless_axes)
 
         assert cfg_scale > 1.0, 'CFG_Scale (-C) must be >1.0'
         assert threshold >= 0.0, '--threshold must be >=0.0'
@@ -962,9 +967,15 @@ class Generate:
     def sample_to_lowres_estimated_image(self, samples):
         return self._make_base().sample_to_lowres_estimated_image(samples)
 
+    def _set_sampler(self):
+        if isinstance(self.model, DiffusionPipeline):
+            return self._set_scheduler()
+        else:
+            return self._set_sampler_legacy()
+
     # very repetitive code - can this be simplified? The KSampler names are
     # consistent, at least
-    def _set_sampler(self):
+    def _set_sampler_legacy(self):
         msg = f'>> Setting Sampler to {self.sampler_name}'
         if self.sampler_name == 'plms':
             self.sampler = PLMSSampler(self.model, device=self.device)
@@ -992,6 +1003,44 @@ class Generate:
 
         print(msg)
 
+    def _set_scheduler(self):
+        msg = f'>> Setting Sampler to {self.sampler_name}'
+        default = self.model.scheduler
+        # TODO: Test me! Not all schedulers take the same args.
+        scheduler_args = dict(
+            num_train_timesteps=default.num_train_timesteps,
+            beta_start=default.beta_start,
+            beta_end=default.beta_end,
+            beta_schedule=default.beta_schedule,
+        )
+        trained_betas = getattr(self.model.scheduler, 'trained_betas')
+        if trained_betas is not None:
+            scheduler_args.update(trained_betas=trained_betas)
+        if self.sampler_name == 'plms':
+            raise NotImplementedError("What's the diffusers implementation of PLMS?")
+        elif self.sampler_name == 'ddim':
+            self.sampler = DDIMScheduler(**scheduler_args)
+        elif self.sampler_name == 'k_dpm_2_a':
+            raise NotImplementedError("no diffusers implementation of dpm_2 samplers")
+        elif self.sampler_name == 'k_dpm_2':
+            raise NotImplementedError("no diffusers implementation of dpm_2 samplers")
+        elif self.sampler_name == 'k_euler_a':
+            self.sampler = EulerAncestralDiscreteScheduler(**scheduler_args)
+        elif self.sampler_name == 'k_euler':
+            self.sampler = EulerDiscreteScheduler(**scheduler_args)
+        elif self.sampler_name == 'k_heun':
+            raise NotImplementedError("no diffusers implementation of Heun's sampler")
+        elif self.sampler_name == 'k_lms':
+            self.sampler = LMSDiscreteScheduler(**scheduler_args)
+        else:
+            msg = f'>> Unsupported Sampler: {self.sampler_name}, Defaulting to {default}'
+
+        print(msg)
+
+        if not hasattr(self.sampler, 'uses_inpainting_model'):
+            # FIXME: terrible kludge!
+            self.sampler.uses_inpainting_model = lambda: False
+
     def _load_img(self, img)->Image:
         if isinstance(img, Image.Image):
             image = img

ldm/invoke/generator/base.py

@@ -9,8 +9,8 @@ import traceback
 
 import numpy as np
 import torch
-from PIL import Image, ImageFilter, ImageChops
-import cv2 as cv
+from PIL import Image, ImageFilter
+from diffusers import DiffusionPipeline
 from einops import rearrange
 from pytorch_lightning import seed_everything
 from tqdm import trange
@@ -26,9 +26,9 @@ class Generator:
     downsampling_factor: int
     latent_channels: int
     precision: str
-    model: DiffusionWrapper
+    model: DiffusionWrapper | DiffusionPipeline
 
-    def __init__(self, model: DiffusionWrapper, precision: str):
+    def __init__(self, model: DiffusionWrapper | DiffusionPipeline, precision: str):
         self.model = model
         self.precision = precision
         self.seed = None

ldm/invoke/generator/diffusers_pipeline.py

@@ -1,4 +1,5 @@
 import secrets
+import warnings
 from dataclasses import dataclass
 from typing import List, Optional, Union, Callable
 
@@ -309,6 +310,28 @@ class StableDiffusionGeneratorPipeline(DiffusionPipeline):
             text_embeddings = torch.cat([uncond_embeddings, text_embeddings])
         return text_embeddings
 
+    def get_learned_conditioning(self, c: List[List[str]], return_tokens=True,
+                                 fragment_weights=None, **kwargs):
+        """
+        Compatibility function for ldm.models.diffusion.ddpm.LatentDiffusion.
+        """
+        assert return_tokens == True
+        if fragment_weights:
+            weights = fragment_weights[0]
+            if any(weight != 1.0 for weight in weights):
+                warnings.warn(f"fragment weights not implemented yet {fragment_weights}", stacklevel=2)
+
+        if kwargs:
+            warnings.warn(f"unsupported args {kwargs}", stacklevel=2)
+
+        text_fragments = c[0]
+        text_input = self._tokenize(text_fragments)
+
+        with torch.inference_mode():
+            token_ids = text_input.input_ids.to(self.text_encoder.device)
+            text_embeddings = self.text_encoder(token_ids)[0]
+        return text_embeddings, text_input.input_ids
+
     @torch.inference_mode()
     def _tokenize(self, prompt: Union[str, List[str]]):
         return self.tokenizer(
@@ -319,6 +342,11 @@ class StableDiffusionGeneratorPipeline(DiffusionPipeline):
             return_tensors="pt",
         )
 
+    @property
+    def channels(self) -> int:
+        """Compatible with DiffusionWrapper"""
+        return self.unet.in_channels
+
     def prepare_latents(self, latents, batch_size, height, width, generator, dtype):
         # get the initial random noise unless the user supplied it
         # Unlike in other pipelines, latents need to be generated in the target device

ldm/invoke/generator/txt2img.py

@@ -24,17 +24,8 @@ class Txt2Img(Generator):
         self.perlin = perlin
         uc, c, extra_conditioning_info   = conditioning
 
-        # FIXME: this should probably be either passed in to __init__ instead of model & precision,
-        #     or be constructed in __init__ from those inputs.
-        pipeline = StableDiffusionGeneratorPipeline.from_pretrained(
-            "runwayml/stable-diffusion-v1-5",
-            revision="fp16", torch_dtype=torch.float16,
-            safety_checker=None,  # TODO
-            # scheduler=sampler + ddim_eta,  # TODO
-            # TODO: local_files_only=True
-        )
-        pipeline.unet.to("cuda")
-        pipeline.vae.to("cuda")
+        pipeline = self.model
+        # TODO: customize a new pipeline for the given sampler (Scheduler)
 
         def make_image(x_T) -> PIL.Image.Image:
             # FIXME: restore free_gpu_mem functionality

ldm/invoke/model_cache.py

@@ -4,6 +4,7 @@ They are moved between GPU and CPU as necessary. If CPU memory falls
 below a preset minimum, the least recently used model will be
 cleared and loaded from disk when next needed.
 '''
+from pathlib import Path
 
 import torch
 import os
@@ -20,6 +21,8 @@ import contextlib
 from typing import Union
 from omegaconf import OmegaConf
 from omegaconf.errors import ConfigAttributeError
+
+from ldm.invoke.generator.diffusers_pipeline import StableDiffusionGeneratorPipeline
 from ldm.util import instantiate_from_config, ask_user
 from ldm.invoke.globals import Globals
 from picklescan.scanner import scan_file_path
@@ -91,7 +94,7 @@ class ModelCache(object):
                 assert self.current_model,'** FATAL: no current model to restore to'
                 print(f'** restoring {self.current_model}')
                 self.get_model(self.current_model)
-                return
+                return None
 
         self.current_model = model_name
         self._push_newest_model(model_name)
@@ -277,7 +280,43 @@ class ModelCache(object):
         return model, width, height, model_hash
 
     def _load_diffusers_model(self, mconfig):
-        raise NotImplementedError()  # return pipeline, width, height, model_hash
+        pipeline_args = {}
+
+        if 'repo_name' in mconfig:
+            name_or_path = mconfig['repo_name']
+            model_hash = "FIXME"
+            # model_hash = huggingface_hub.get_hf_file_metadata(url).commit_hash
+        elif 'path' in mconfig:
+            name_or_path = Path(mconfig['path'])
+            # FIXME: What should the model_hash be? A hash of the unet weights? Of all files of all
+            #     the submodels hashed together? The commit ID from the repo?
+            model_hash = "FIXME TOO"
+        else:
+            raise ValueError("Model config must specify either repo_name or path.")
+
+        print(f'>> Loading diffusers model from {name_or_path}')
+
+        if self.precision == 'float16':
+            print('   | Using faster float16 precision')
+            pipeline_args.update(revision="fp16", torch_dtype=torch.float16)
+        else:
+            # TODO: more accurately, "using the model's default precision."
+            #     How do we find out what that is?
+            print('   | Using more accurate float32 precision')
+
+        pipeline = StableDiffusionGeneratorPipeline.from_pretrained(
+            name_or_path,
+            safety_checker=None,  # TODO
+            # TODO: alternate VAE
+            # TODO: local_files_only=True
+            **pipeline_args
+        )
+        pipeline.to(self.device)
+
+        width = pipeline.vae.sample_size
+        height = pipeline.vae.sample_size
+
+        return pipeline, width, height, model_hash
 
     def offload_model(self, model_name:str):
         '''