InvokeAI/ldm/invoke/model_cache.py

360 lines
13 KiB
Python

'''
Manage a cache of Stable Diffusion model files for fast switching.
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.
'''
import torch
import os
import io
import time
import gc
import hashlib
import psutil
import transformers
import traceback
import os
from sys import getrefcount
from omegaconf import OmegaConf
from omegaconf.errors import ConfigAttributeError
from ldm.util import instantiate_from_config
DEFAULT_MAX_MODELS=2
class ModelCache(object):
def __init__(self, config:OmegaConf, device_type:str, precision:str, max_loaded_models=DEFAULT_MAX_MODELS):
'''
Initialize with the path to the models.yaml config file,
the torch device type, and precision. The optional
min_avail_mem argument specifies how much unused system
(CPU) memory to preserve. The cache of models in RAM will
grow until this value is approached. Default is 2G.
'''
# prevent nasty-looking CLIP log message
transformers.logging.set_verbosity_error()
self.config = config
self.precision = precision
self.device = torch.device(device_type)
self.max_loaded_models = max_loaded_models
self.models = {}
self.stack = [] # this is an LRU FIFO
self.current_model = None
def get_model(self, model_name:str):
'''
Given a model named identified in models.yaml, return
the model object. If in RAM will load into GPU VRAM.
If on disk, will load from there.
'''
if model_name not in self.config:
print(f'** "{model_name}" is not a known model name. Please check your models.yaml file')
return None
if self.current_model != model_name:
self.unload_model(self.current_model)
if model_name in self.models:
requested_model = self.models[model_name]['model']
print(f'>> Retrieving model {model_name} from system RAM cache')
self.models[model_name]['model'] = self._model_from_cpu(requested_model)
width = self.models[model_name]['width']
height = self.models[model_name]['height']
hash = self.models[model_name]['hash']
else: # we're about to load a new model, so potentially unload the least recently used one
self._check_cache_size()
try:
requested_model, width, height, hash = self._load_model(model_name)
self.models[model_name] = {}
self.models[model_name]['model'] = requested_model
self.models[model_name]['width'] = width
self.models[model_name]['height'] = height
self.models[model_name]['hash'] = hash
except Exception as e:
print(f'** model {model_name} could not be loaded: {str(e)}')
print(traceback.format_exc())
print(f'** restoring {self.current_model}')
self.get_model(self.current_model)
return None
self.current_model = model_name
self._push_newest_model(model_name)
return {
'model':requested_model,
'width':width,
'height':height,
'hash': hash
}
def default_model(self) -> str:
'''
Returns the name of the default model, or None
if none is defined.
'''
for model_name in self.config:
if self.config[model_name].get('default',False):
return model_name
return None
def set_default_model(self,model_name:str):
'''
Set the default model. The change will not take
effect until you call model_cache.commit()
'''
assert model_name in self.models,f"unknown model '{model_name}'"
for model in self.models:
self.models[model].pop('default',None)
self.models[model_name]['default'] = True
def list_models(self) -> dict:
'''
Return a dict of models in the format:
{ model_name1: {'status': ('active'|'cached'|'not loaded'),
'description': description,
},
model_name2: { etc }
'''
result = {}
for name in self.config:
try:
description = self.config[name].description
except ConfigAttributeError:
description = '<no description>'
if self.current_model == name:
status = 'active'
elif name in self.models:
status = 'cached'
else:
status = 'not loaded'
result[name]={}
result[name]['status']=status
result[name]['description']=description
return result
def print_models(self):
'''
Print a table of models, their descriptions, and load status
'''
models = self.list_models()
for name in models:
line = f'{name:25s} {models[name]["status"]:>10s} {models[name]["description"]}'
if models[name]['status'] == 'active':
print(f'\033[1m{line}\033[0m')
else:
print(line)
def del_model(self, model_name:str) ->bool:
'''
Delete the named model.
'''
omega = self.config
del omega[model_name]
if model_name in self.stack:
self.stack.remove(model_name)
return True
def add_model(self, model_name:str, model_attributes:dict, clobber=False) ->True:
'''
Update the named model with a dictionary of attributes. Will fail with an
assertion error if the name already exists. Pass clobber=True to overwrite.
On a successful update, the config will be changed in memory and the
method will return True. Will fail with an assertion error if provided
attributes are incorrect or the model name is missing.
'''
omega = self.config
# check that all the required fields are present
for field in ('description','weights','height','width','config'):
assert field in model_attributes, f'required field {field} is missing'
assert (clobber or model_name not in omega), f'attempt to overwrite existing model definition "{model_name}"'
config = omega[model_name] if model_name in omega else {}
for field in model_attributes:
config[field] = model_attributes[field]
omega[model_name] = config
if clobber:
self._invalidate_cached_model(model_name)
return True
def _check_cache_size(self):
num_loaded_models = len(self.models)
if num_loaded_models >= self.max_loaded_models:
least_recent_model = self._pop_oldest_model()
print(f'>> Cache limit (max={self.max_loaded_models}) reached. Purging {least_recent_model}')
if least_recent_model is not None:
del self.models[least_recent_model]
gc.collect()
else:
print(f'>> Model will be cached in CPU')
def _load_model(self, model_name:str):
"""Load and initialize the model from configuration variables passed at object creation time"""
if model_name not in self.config:
print(f'"{model_name}" is not a known model name. Please check your models.yaml file')
return None
mconfig = self.config[model_name]
config = mconfig.config
weights = mconfig.weights
vae = mconfig.get('vae',None)
width = mconfig.width
height = mconfig.height
print(f'>> Loading {model_name} from {weights}')
# for usage statistics
if self._has_cuda():
torch.cuda.reset_peak_memory_stats()
torch.cuda.empty_cache()
tic = time.time()
# this does the work
c = OmegaConf.load(config)
with open(weights,'rb') as f:
weight_bytes = f.read()
model_hash = self._cached_sha256(weights,weight_bytes)
pl_sd = torch.load(io.BytesIO(weight_bytes), map_location='cpu')
del weight_bytes
sd = pl_sd['state_dict']
model = instantiate_from_config(c.model)
m, u = model.load_state_dict(sd, strict=False)
if self.precision == 'float16':
print(' | Using faster float16 precision')
model.to(torch.float16)
else:
print(' | Using more accurate float32 precision')
# look and load a matching vae file. Code borrowed from AUTOMATIC1111 modules/sd_models.py
if vae:
if os.path.exists(vae):
print(f' | Loading VAE weights from: {vae}')
vae_ckpt = torch.load(vae, map_location="cpu")
vae_dict = {k: v for k, v in vae_ckpt["state_dict"].items() if k[0:4] != "loss"}
model.first_stage_model.load_state_dict(vae_dict, strict=False)
else:
print(f' | VAE file {vae} not found. Skipping.')
model.to(self.device)
# model.to doesn't change the cond_stage_model.device used to move the tokenizer output, so set it here
model.cond_stage_model.device = self.device
model.eval()
for m in model.modules():
if isinstance(m, (torch.nn.Conv2d, torch.nn.ConvTranspose2d)):
m._orig_padding_mode = m.padding_mode
# usage statistics
toc = time.time()
print(f'>> Model loaded in', '%4.2fs' % (toc - tic))
if self._has_cuda():
print(
'>> Max VRAM used to load the model:',
'%4.2fG' % (torch.cuda.max_memory_allocated() / 1e9),
'\n>> Current VRAM usage:'
'%4.2fG' % (torch.cuda.memory_allocated() / 1e9),
)
return model, width, height, model_hash
def unload_model(self, model_name:str):
if model_name not in self.models:
return
print(f'>> Unloading {model_name} from GPU')
model = self.models[model_name]['model']
self.models[model_name]['model'] = self._model_to_cpu(model)
gc.collect()
if self._has_cuda():
torch.cuda.empty_cache()
def commit(self,config_file_path:str):
'''
Write current configuration out to the indicated file.
'''
yaml_str = OmegaConf.to_yaml(self.config)
tmpfile = os.path.join(os.path.dirname(config_file_path),'new_config.tmp')
with open(tmpfile, 'w') as outfile:
outfile.write(self.preamble())
outfile.write(yaml_str)
os.rename(tmpfile,config_file_path)
def preamble(self):
'''
Returns the preamble for the config file.
'''
return '''# This file describes the alternative machine learning models
# available to InvokeAI script.
#
# To add a new model, follow the examples below. Each
# model requires a model config file, a weights file,
# and the width and height of the images it
# was trained on.
'''
def _invalidate_cached_model(self,model_name:str):
self.unload_model(model_name)
if model_name in self.stack:
self.stack.remove(model_name)
self.models.pop(model_name,None)
def _model_to_cpu(self,model):
if self.device != 'cpu':
model.cond_stage_model.device = 'cpu'
model.first_stage_model.to('cpu')
model.cond_stage_model.to('cpu')
model.model.to('cpu')
return model.to('cpu')
else:
return model
def _model_from_cpu(self,model):
if self.device != 'cpu':
model.to(self.device)
model.first_stage_model.to(self.device)
model.cond_stage_model.to(self.device)
model.cond_stage_model.device = self.device
return model
def _pop_oldest_model(self):
'''
Remove the first element of the FIFO, which ought
to be the least recently accessed model. Do not
pop the last one, because it is in active use!
'''
return self.stack.pop(0)
def _push_newest_model(self,model_name:str):
'''
Maintain a simple FIFO. First element is always the
least recent, and last element is always the most recent.
'''
try:
self.stack.remove(model_name)
except ValueError:
pass
self.stack.append(model_name)
def _has_cuda(self):
return self.device.type == 'cuda'
def _cached_sha256(self,path,data):
dirname = os.path.dirname(path)
basename = os.path.basename(path)
base, _ = os.path.splitext(basename)
hashpath = os.path.join(dirname,base+'.sha256')
if os.path.exists(hashpath) and os.path.getmtime(path) <= os.path.getmtime(hashpath):
with open(hashpath) as f:
hash = f.read()
return hash
print(f'>> Calculating sha256 hash of weights file')
tic = time.time()
sha = hashlib.sha256()
sha.update(data)
hash = sha.hexdigest()
toc = time.time()
print(f'>> sha256 = {hash}','(%4.2fs)' % (toc - tic))
with open(hashpath,'w') as f:
f.write(hash)
return hash