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# NEW
import os
# from functools import partial
from pickle import UnpicklingError
from typing import Dict, Set, Tuple, Union
import flax.linen as nn
import jax
import jax.numpy as jnp
from flax.core.frozen_dict import FrozenDict, unfreeze
from flax.serialization import from_bytes, to_bytes
from flax.traverse_util import flatten_dict, unflatten_dict
from jax.random import PRNGKey
from transformers.configuration_utils import PretrainedConfig
from transformers.file_utils import (
FLAX_WEIGHTS_NAME,
WEIGHTS_NAME,
PushToHubMixin,
cached_path,
hf_bucket_url,
is_offline_mode,
is_remote_url,
)
from transformers.modeling_flax_pytorch_utils import (
load_pytorch_checkpoint_in_flax_state_dict,
)
from transformers.utils import logging
from .generation_clip_vision_utils import FlaxCLIPVisionMBartGenerationMixin
logger = logging.get_logger(__name__)
class FlaxCLIPVisionMBartPreTrainedModel(
PushToHubMixin, FlaxCLIPVisionMBartGenerationMixin
):
r"""
Base class for all models.
:class:`~transformers.FlaxPreTrainedModel` takes care of storing the configuration of the models and handles
methods for loading, downloading and saving models.
Class attributes (overridden by derived classes):
- **config_class** (:class:`~transformers.PretrainedConfig`) -- A subclass of
:class:`~transformers.PretrainedConfig` to use as configuration class for this model architecture.
- **base_model_prefix** (:obj:`str`) -- A string indicating the attribute associated to the base model in
derived classes of the same architecture adding modules on top of the base model.
"""
config_class = None
base_model_prefix = ""
def __init__(
self,
config: PretrainedConfig,
module: nn.Module,
input_shape: Tuple = (1, 1),
seed: int = 0,
dtype: jnp.dtype = jnp.float32,
):
if config is None:
raise ValueError("config cannot be None")
if module is None:
raise ValueError("module cannot be None")
# Those are private to be exposed as typed property on derived classes.
self._config = config
self._module = module
# Those are public as their type is generic to every derived classes.
self.key = PRNGKey(seed)
self.dtype = dtype
# randomly initialized parameters
random_params = self.init_weights(self.key, input_shape)
# save required_params as set
self._required_params = set(flatten_dict(unfreeze(random_params)).keys())
self.params = random_params
def init_weights(self, rng: jax.random.PRNGKey, input_shape: Tuple) -> Dict:
raise NotImplementedError(f"init method has to be implemented for {self}")
@classmethod
def _from_config(cls, config, **kwargs):
"""
All context managers that the model should be initialized under go here.
"""
return cls(config, **kwargs)
@property
def config(self) -> PretrainedConfig:
return self._config
@property
def module(self) -> nn.Module:
return self._module
@property
def params(self) -> Union[Dict, FrozenDict]:
return self._params
@property
def required_params(self) -> Set:
return self._required_params
@params.setter
def params(self, params: Union[Dict, FrozenDict]):
if isinstance(params, FrozenDict):
params = unfreeze(params)
param_keys = set(flatten_dict(params).keys())
if len(self.required_params - param_keys) > 0:
raise ValueError(
"Some parameters are missing. Make sure that `params` include the following "
f"parameters {self.required_params - param_keys}"
)
self._params = params
@classmethod
def from_pretrained(
cls,
pretrained_model_name_or_path: Union[str, os.PathLike],
dtype: jnp.dtype = jnp.float32,
*model_args,
**kwargs,
):
r"""
Instantiate a pretrained flax model from a pre-trained model configuration.
The warning `Weights from XXX not initialized from pretrained model` means that the weights of XXX do not come
pretrained with the rest of the model. It is up to you to train those weights with a downstream fine-tuning
task.
The warning `Weights from XXX not used in YYY` means that the layer XXX is not used by YYY, therefore those
weights are discarded.
Parameters:
pretrained_model_name_or_path (:obj:`str` or :obj:`os.PathLike`):
Can be either:
- A string, the `model id` of a pretrained model hosted inside a model repo on huggingface.co.
Valid model ids can be located at the root-level, like ``bert-base-uncased``, or namespaced under
a user or organization name, like ``dbmdz/bert-base-german-cased``.
- A path to a `directory` containing model weights saved using
:func:`~transformers.FlaxPreTrainedModel.save_pretrained`, e.g., ``./my_model_directory/``.
- A path or url to a `pt index checkpoint file` (e.g, ``./tf_model/model.ckpt.index``). In this
case, ``from_pt`` should be set to :obj:`True`.
model_args (sequence of positional arguments, `optional`):
All remaning positional arguments will be passed to the underlying model's ``__init__`` method.
config (:obj:`Union[PretrainedConfig, str, os.PathLike]`, `optional`):
Can be either:
- an instance of a class derived from :class:`~transformers.PretrainedConfig`,
- a string or path valid as input to :func:`~transformers.PretrainedConfig.from_pretrained`.
Configuration for the model to use instead of an automatically loaded configuation. Configuration can
be automatically loaded when:
- The model is a model provided by the library (loaded with the `model id` string of a pretrained
model).
- The model was saved using :func:`~transformers.PreTrainedModel.save_pretrained` and is reloaded
by supplying the save directory.
- The model is loaded by supplying a local directory as ``pretrained_model_name_or_path`` and a
configuration JSON file named `config.json` is found in the directory.
cache_dir (:obj:`Union[str, os.PathLike]`, `optional`):
Path to a directory in which a downloaded pretrained model configuration should be cached if the
standard cache should not be used.
from_pt (:obj:`bool`, `optional`, defaults to :obj:`False`):
Load the model weights from a PyTorch checkpoint save file (see docstring of
``pretrained_model_name_or_path`` argument).
force_download (:obj:`bool`, `optional`, defaults to :obj:`False`):
Whether or not to force the (re-)download of the model weights and configuration files, overriding the
cached versions if they exist.
resume_download (:obj:`bool`, `optional`, defaults to :obj:`False`):
Whether or not to delete incompletely received files. Will attempt to resume the download if such a
file exists.
proxies (:obj:`Dict[str, str], `optional`):
A dictionary of proxy servers to use by protocol or endpoint, e.g., :obj:`{'http': 'foo.bar:3128',
'http://hostname': 'foo.bar:4012'}`. The proxies are used on each request.
local_files_only(:obj:`bool`, `optional`, defaults to :obj:`False`):
Whether or not to only look at local files (i.e., do not try to download the model).
revision(:obj:`str`, `optional`, defaults to :obj:`"main"`):
The specific model version to use. It can be a branch name, a tag name, or a commit id, since we use a
git-based system for storing models and other artifacts on huggingface.co, so ``revision`` can be any
identifier allowed by git.
kwargs (remaining dictionary of keyword arguments, `optional`):
Can be used to update the configuration object (after it being loaded) and initiate the model (e.g.,
:obj:`output_attentions=True`). Behaves differently depending on whether a ``config`` is provided or
automatically loaded:
- If a configuration is provided with ``config``, ``**kwargs`` will be directly passed to the
underlying model's ``__init__`` method (we assume all relevant updates to the configuration have
already been done)
- If a configuration is not provided, ``kwargs`` will be first passed to the configuration class
initialization function (:func:`~transformers.PretrainedConfig.from_pretrained`). Each key of
``kwargs`` that corresponds to a configuration attribute will be used to override said attribute
with the supplied ``kwargs`` value. Remaining keys that do not correspond to any configuration
attribute will be passed to the underlying model's ``__init__`` function.
Examples::
>>> from transformers import BertConfig, FlaxBertModel
>>> # Download model and configuration from huggingface.co and cache.
>>> model = FlaxBertModel.from_pretrained('bert-base-cased')
>>> # Model was saved using `save_pretrained('./test/saved_model/')` (for example purposes, not runnable).
>>> model = FlaxBertModel.from_pretrained('./test/saved_model/')
>>> # Loading from a PyTorch checkpoint file instead of a PyTorch model (slower, for example purposes, not runnable).
>>> config = BertConfig.from_json_file('./pt_model/config.json')
>>> model = FlaxBertModel.from_pretrained('./pt_model/pytorch_model.bin', from_pt=True, config=config)
"""
config = kwargs.pop("config", None)
cache_dir = kwargs.pop("cache_dir", None)
from_pt = kwargs.pop("from_pt", False)
force_download = kwargs.pop("force_download", False)
resume_download = kwargs.pop("resume_download", False)
proxies = kwargs.pop("proxies", None)
local_files_only = kwargs.pop("local_files_only", False)
use_auth_token = kwargs.pop("use_auth_token", None)
revision = kwargs.pop("revision", None)
from_pipeline = kwargs.pop("_from_pipeline", None)
from_auto_class = kwargs.pop("_from_auto", False)
user_agent = {
"file_type": "model",
"framework": "flax",
"from_auto_class": from_auto_class,
}
if from_pipeline is not None:
user_agent["using_pipeline"] = from_pipeline
if is_offline_mode() and not local_files_only:
logger.info("Offline mode: forcing local_files_only=True")
local_files_only = True
# Load config if we don't provide a configuration
if not isinstance(config, PretrainedConfig):
config_path = (
config if config is not None else pretrained_model_name_or_path
)
config, model_kwargs = cls.config_class.from_pretrained(
config_path,
*model_args,
cache_dir=cache_dir,
return_unused_kwargs=True,
force_download=force_download,
resume_download=resume_download,
proxies=proxies,
local_files_only=local_files_only,
use_auth_token=use_auth_token,
revision=revision,
_from_auto=from_auto_class,
_from_pipeline=from_pipeline,
**kwargs,
)
else:
model_kwargs = kwargs
# Add the dtype to model_kwargs
model_kwargs["dtype"] = dtype
# Load model
if pretrained_model_name_or_path is not None:
if os.path.isdir(pretrained_model_name_or_path):
if from_pt and os.path.isfile(
os.path.join(pretrained_model_name_or_path, WEIGHTS_NAME)
):
# Load from a PyTorch checkpoint
archive_file = os.path.join(
pretrained_model_name_or_path, WEIGHTS_NAME
)
elif os.path.isfile(
os.path.join(pretrained_model_name_or_path, FLAX_WEIGHTS_NAME)
):
# Load from a Flax checkpoint
archive_file = os.path.join(
pretrained_model_name_or_path, FLAX_WEIGHTS_NAME
)
else:
raise EnvironmentError(
f"Error no file named {[FLAX_WEIGHTS_NAME, WEIGHTS_NAME]} found in directory "
f"{pretrained_model_name_or_path} or `from_pt` set to False"
)
elif os.path.isfile(pretrained_model_name_or_path) or is_remote_url(
pretrained_model_name_or_path
):
archive_file = pretrained_model_name_or_path
else:
archive_file = hf_bucket_url(
pretrained_model_name_or_path,
filename=WEIGHTS_NAME if from_pt else FLAX_WEIGHTS_NAME,
revision=revision,
)
# redirect to the cache, if necessary
try:
resolved_archive_file = cached_path(
archive_file,
cache_dir=cache_dir,
force_download=force_download,
proxies=proxies,
resume_download=resume_download,
local_files_only=local_files_only,
use_auth_token=use_auth_token,
user_agent=user_agent,
)
except EnvironmentError as err:
logger.error(err)
msg = (
f"Can't load weights for '{pretrained_model_name_or_path}'. Make sure that:\n\n"
f"- '{pretrained_model_name_or_path}' is a correct model identifier listed on 'https://huggingface.co/models'\n\n"
f"- or '{pretrained_model_name_or_path}' is the correct path to a directory containing a file named {WEIGHTS_NAME}.\n\n"
)
raise EnvironmentError(msg)
if resolved_archive_file == archive_file:
logger.info(f"loading weights file {archive_file}")
else:
logger.info(
f"loading weights file {archive_file} from cache at {resolved_archive_file}"
)
else:
resolved_archive_file = None
# init random models
model = cls(config, *model_args, **model_kwargs)
if from_pt:
state = load_pytorch_checkpoint_in_flax_state_dict(
model, resolved_archive_file
)
else:
with open(resolved_archive_file, "rb") as state_f:
try:
state = from_bytes(cls, state_f.read())
except UnpicklingError:
raise EnvironmentError(
f"Unable to convert {archive_file} to Flax deserializable object. "
)
# make sure all arrays are stored as jnp.arrays
# NOTE: This is to prevent a bug this will be fixed in Flax >= v0.3.4:
# https://github.com/google/flax/issues/1261
state = jax.tree_util.tree_map(jnp.array, state)
# if model is base model only use model_prefix key
if (
cls.base_model_prefix not in dict(model.params)
and cls.base_model_prefix in state
):
state = state[cls.base_model_prefix]
# if model is head model and we are loading weights from base model
# we initialize new params dict with base_model_prefix
if (
cls.base_model_prefix in dict(model.params)
and cls.base_model_prefix not in state
):
state = {cls.base_model_prefix: state}
# flatten dicts
state = flatten_dict(state)
random_state = flatten_dict(unfreeze(model.params))
missing_keys = model.required_params - set(state.keys())
unexpected_keys = set(state.keys()) - model.required_params
# add missing keys as random parameters
for missing_key in missing_keys:
state[missing_key] = random_state[missing_key]
# remove unexpected keys to not be saved again
for unexpected_key in unexpected_keys:
del state[unexpected_key]
if len(unexpected_keys) > 0:
logger.warning(
f"Some weights of the model checkpoint at {pretrained_model_name_or_path} were not used when "
f"initializing {model.__class__.__name__}: {unexpected_keys}\n"
f"- This IS expected if you are initializing {model.__class__.__name__} from the checkpoint of a model trained on another task "
f"or with another architecture (e.g. initializing a BertForSequenceClassification model from a BertForPreTraining model).\n"
f"- This IS NOT expected if you are initializing {model.__class__.__name__} from the checkpoint of a model that you expect "
f"to be exactly identical (initializing a BertForSequenceClassification model from a BertForSequenceClassification model)."
)
else:
logger.info(
f"All model checkpoint weights were used when initializing {model.__class__.__name__}.\n"
)
if len(missing_keys) > 0:
logger.warning(
f"Some weights of {model.__class__.__name__} were not initialized from the model checkpoint at {pretrained_model_name_or_path} "
f"and are newly initialized: {missing_keys}\n"
f"You should probably TRAIN this model on a down-stream task to be able to use it for predictions and inference."
)
else:
logger.info(
f"All the weights of {model.__class__.__name__} were initialized from the model checkpoint at {pretrained_model_name_or_path}.\n"
f"If your task is similar to the task the model of the checkpoint was trained on, "
f"you can already use {model.__class__.__name__} for predictions without further training."
)
# set correct parameters
model.params = unflatten_dict(state)
return model
def save_pretrained(
self,
save_directory: Union[str, os.PathLike],
params=None,
push_to_hub=False,
**kwargs,
):
"""
Save a model and its configuration file to a directory, so that it can be re-loaded using the
`:func:`~transformers.FlaxPreTrainedModel.from_pretrained`` class method
Arguments:
save_directory (:obj:`str` or :obj:`os.PathLike`):
Directory to which to save. Will be created if it doesn't exist.
push_to_hub (:obj:`bool`, `optional`, defaults to :obj:`False`):
Whether or not to push your model to the Hugging Face model hub after saving it.
.. warning::
Using :obj:`push_to_hub=True` will synchronize the repository you are pushing to with
:obj:`save_directory`, which requires :obj:`save_directory` to be a local clone of the repo you are
pushing to if it's an existing folder. Pass along :obj:`temp_dir=True` to use a temporary directory
instead.
kwargs:
Additional key word arguments passed along to the
:meth:`~transformers.file_utils.PushToHubMixin.push_to_hub` method.
"""
if os.path.isfile(save_directory):
logger.error(
f"Provided path ({save_directory}) should be a directory, not a file"
)
return
if push_to_hub:
commit_message = kwargs.pop("commit_message", None)
repo = self._create_or_get_repo(save_directory, **kwargs)
os.makedirs(save_directory, exist_ok=True)
# get abs dir
save_directory = os.path.abspath(save_directory)
# save config as well
self.config.architectures = [self.__class__.__name__[4:]]
self.config.save_pretrained(save_directory)
# save model
output_model_file = os.path.join(save_directory, FLAX_WEIGHTS_NAME)
with open(output_model_file, "wb") as f:
params = params if params is not None else self.params
model_bytes = to_bytes(params)
f.write(model_bytes)
logger.info(f"Model weights saved in {output_model_file}")
if push_to_hub:
url = self._push_to_hub(repo, commit_message=commit_message)
logger.info(f"Model pushed to the hub in this commit: {url}")