diff --git "a/llmeval-env/lib/python3.10/site-packages/transformers/modeling_tf_utils.py" "b/llmeval-env/lib/python3.10/site-packages/transformers/modeling_tf_utils.py" new file mode 100644--- /dev/null +++ "b/llmeval-env/lib/python3.10/site-packages/transformers/modeling_tf_utils.py" @@ -0,0 +1,3553 @@ +# coding=utf-8 +# Copyright 2018 The Google AI Language Team Authors and The HuggingFace Inc. team. +# Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +"""TF general model utils.""" + +from __future__ import annotations + +import functools +import gc +import inspect +import json +import os +import pickle +import re +import warnings +from collections.abc import Mapping +from pathlib import Path +from typing import TYPE_CHECKING, Any, Callable, Dict, List, Optional, Union + +import h5py +import numpy as np +import tensorflow as tf +from packaging.version import parse + +from . import DataCollatorWithPadding, DefaultDataCollator +from .activations_tf import get_tf_activation +from .configuration_utils import PretrainedConfig +from .dynamic_module_utils import custom_object_save +from .generation import GenerationConfig, TFGenerationMixin +from .tf_utils import ( + convert_batch_encoding, + expand_1d, + load_attributes_from_hdf5_group, + save_attributes_to_hdf5_group, + shape_list, +) +from .utils import ( + SAFE_WEIGHTS_INDEX_NAME, + SAFE_WEIGHTS_NAME, + TF2_WEIGHTS_INDEX_NAME, + TF2_WEIGHTS_NAME, + TF_WEIGHTS_NAME, + WEIGHTS_INDEX_NAME, + WEIGHTS_NAME, + ModelOutput, + PushToHubMixin, + cached_file, + download_url, + find_labels, + has_file, + is_offline_mode, + is_remote_url, + is_safetensors_available, + is_tf_symbolic_tensor, + logging, + requires_backends, + working_or_temp_dir, +) +from .utils.hub import convert_file_size_to_int, get_checkpoint_shard_files + + +if is_safetensors_available(): + from safetensors import safe_open + from safetensors.tensorflow import save_file as safe_save_file + +if TYPE_CHECKING: + from . import PreTrainedTokenizerBase + +logger = logging.get_logger(__name__) + +if "TF_USE_LEGACY_KERAS" not in os.environ: + os.environ["TF_USE_LEGACY_KERAS"] = "1" # Compatibility fix to make sure tf.keras stays at Keras 2 +elif os.environ["TF_USE_LEGACY_KERAS"] != "1": + logger.warning( + "Transformers is only compatible with Keras 2, but you have explicitly set `TF_USE_LEGACY_KERAS` to `0`. " + "This may result in unexpected behaviour or errors if Keras 3 objects are passed to Transformers models." + ) + +try: + import tf_keras as keras + from tf_keras import backend as K +except (ModuleNotFoundError, ImportError): + import keras + from keras import backend as K + + if parse(keras.__version__).major > 2: + raise ValueError( + "Your currently installed version of Keras is Keras 3, but this is not yet supported in " + "Transformers. Please install the backwards-compatible tf-keras package with " + "`pip install tf-keras`." + ) + + +tf_logger = tf.get_logger() + +TFModelInputType = Union[ + List[tf.Tensor], + List[np.ndarray], + Dict[str, tf.Tensor], + Dict[str, np.ndarray], + tf.Tensor, + np.ndarray, +] + + +def dummy_loss(y_true, y_pred): + if y_pred.shape.rank <= 1: + return y_pred + else: + reduction_axes = list(range(1, y_pred.shape.rank)) + return tf.reduce_mean(y_pred, axis=reduction_axes) + + +class TFModelUtilsMixin: + """ + A few utilities for `keras.Model`, to be used as a mixin. + """ + + def num_parameters(self, only_trainable: bool = False) -> int: + """ + Get the number of (optionally, trainable) parameters in the model. + + Args: + only_trainable (`bool`, *optional*, defaults to `False`): + Whether or not to return only the number of trainable parameters + + Returns: + `int`: The number of parameters. + """ + if only_trainable: + return int(sum(np.prod(w.shape.as_list()) for w in self.trainable_variables)) + else: + return self.count_params() + + +def keras_serializable(cls): + """ + Decorate a Keras Layer class to support Keras serialization. + + This is done by: + + 1. Adding a `transformers_config` dict to the Keras config dictionary in `get_config` (called by Keras at + serialization time. + 2. Wrapping `__init__` to accept that `transformers_config` dict (passed by Keras at deserialization time) and + convert it to a config object for the actual layer initializer. + 3. Registering the class as a custom object in Keras (if the Tensorflow version supports this), so that it does not + need to be supplied in `custom_objects` in the call to `keras.models.load_model`. + + Args: + cls (a `keras.layers.Layers subclass`): + Typically a `TF.MainLayer` class in this project, in general must accept a `config` argument to its + initializer. + + Returns: + The same class object, with modifications for Keras deserialization. + """ + initializer = cls.__init__ + + config_class = getattr(cls, "config_class", None) + if config_class is None: + raise AttributeError("Must set `config_class` to use @keras_serializable") + + @functools.wraps(initializer) + def wrapped_init(self, *args, **kwargs): + config = args[0] if args and isinstance(args[0], PretrainedConfig) else kwargs.pop("config", None) + + if isinstance(config, dict): + config = config_class.from_dict(config) + initializer(self, config, *args, **kwargs) + elif isinstance(config, PretrainedConfig): + if len(args) > 0: + initializer(self, *args, **kwargs) + else: + initializer(self, config, *args, **kwargs) + else: + raise ValueError("Must pass either `config` (PretrainedConfig) or `config` (dict)") + + self._config = config + self._kwargs = kwargs + + cls.__init__ = wrapped_init + + if not hasattr(cls, "get_config"): + raise TypeError("Only use @keras_serializable on keras.layers.Layer subclasses") + if hasattr(cls.get_config, "_is_default"): + + def get_config(self): + cfg = super(cls, self).get_config() + cfg["config"] = self._config.to_dict() + cfg.update(self._kwargs) + return cfg + + cls.get_config = get_config + + cls._keras_serializable = True + if hasattr(keras.utils, "register_keras_serializable"): + cls = keras.utils.register_keras_serializable()(cls) + return cls + + +class TFCausalLanguageModelingLoss: + """ + Loss function suitable for causal language modeling (CLM), that is, the task of guessing the next token. + + + + Any label of -100 will be ignored (along with the corresponding logits) in the loss computation. + + + """ + + def hf_compute_loss(self, labels, logits): + loss_fn = keras.losses.SparseCategoricalCrossentropy(from_logits=True, reduction=keras.losses.Reduction.NONE) + if self.config.tf_legacy_loss: + # make sure only labels that are not equal to -100 affect the loss + active_loss = tf.not_equal(tf.reshape(labels, (-1,)), -100) + reduced_logits = tf.boolean_mask(tf.reshape(logits, (-1, shape_list(logits)[2])), active_loss) + labels = tf.boolean_mask(tf.reshape(labels, (-1,)), active_loss) + return loss_fn(labels, reduced_logits) + + # Clip negative labels to zero here to avoid NaNs and errors - those positions will get masked later anyway + unmasked_loss = loss_fn(tf.nn.relu(labels), logits) + # make sure only labels that are not equal to -100 affect the loss + loss_mask = tf.cast(labels != -100, dtype=unmasked_loss.dtype) + masked_loss = unmasked_loss * loss_mask + reduced_masked_loss = tf.reduce_sum(masked_loss) / tf.reduce_sum(loss_mask) + return tf.reshape(reduced_masked_loss, (1,)) + + +class TFQuestionAnsweringLoss: + """ + Loss function suitable for question answering. + """ + + def hf_compute_loss(self, labels, logits): + loss_fn = keras.losses.SparseCategoricalCrossentropy(from_logits=True, reduction=keras.losses.Reduction.NONE) + start_loss = loss_fn(labels["start_position"], logits[0]) + end_loss = loss_fn(labels["end_position"], logits[1]) + + return (start_loss + end_loss) / 2.0 + + +class TFTokenClassificationLoss: + """ + Loss function suitable for token classification. + + + + Any label of -100 will be ignored (along with the corresponding logits) in the loss computation. + + + """ + + def hf_compute_loss(self, labels, logits): + loss_fn = keras.losses.SparseCategoricalCrossentropy(from_logits=True, reduction=keras.losses.Reduction.NONE) + if tf.executing_eagerly(): # Data-dependent conditionals are forbidden in XLA + if tf.math.reduce_any(labels == -1): + tf.print("Using `-1` to mask the loss for the token is deprecated. Please use `-100` instead.") + + if self.config.tf_legacy_loss: + # make sure only labels that are not equal to -100 + # are taken into account as loss + if tf.math.reduce_any(labels == -1): + tf.print("Using `-1` to mask the loss for the token is deprecated. Please use `-100` instead.") + active_loss = tf.reshape(labels, (-1,)) != -1 + else: + active_loss = tf.reshape(labels, (-1,)) != -100 + reduced_logits = tf.boolean_mask(tf.reshape(logits, (-1, shape_list(logits)[2])), active_loss) + labels = tf.boolean_mask(tf.reshape(labels, (-1,)), active_loss) + + return loss_fn(labels, reduced_logits) + + # Clip negative labels to zero here to avoid NaNs and errors - those positions will get masked later anyway + unmasked_loss = loss_fn(tf.nn.relu(labels), logits) + # make sure only labels that are not equal to -100 or -1 + # are taken into account as loss + loss_mask = tf.cast(labels >= 0, dtype=unmasked_loss.dtype) + # Avoid possible division by zero later + # Masked positions will have a loss of NaN because -100 and -1 are not valid labels + masked_loss = unmasked_loss * loss_mask + reduced_masked_loss = tf.reduce_sum(masked_loss) / tf.reduce_sum(loss_mask) + return tf.reshape(reduced_masked_loss, (1,)) + + +class TFSequenceClassificationLoss: + """ + Loss function suitable for sequence classification. + """ + + def hf_compute_loss(self, labels, logits): + if logits.shape.rank == 1 or logits.shape[1] == 1: + loss_fn = keras.losses.MeanSquaredError(reduction=keras.losses.Reduction.NONE) + if labels.shape.rank == 1: + # MeanSquaredError returns a scalar loss if the labels are 1D, so avoid that + labels = tf.expand_dims(labels, axis=-1) + else: + loss_fn = keras.losses.SparseCategoricalCrossentropy( + from_logits=True, reduction=keras.losses.Reduction.NONE + ) + + return loss_fn(labels, logits) + + +class TFMultipleChoiceLoss: + """Loss function suitable for multiple choice tasks.""" + + def hf_compute_loss(self, labels, logits): + loss_fn = keras.losses.SparseCategoricalCrossentropy(from_logits=True, reduction=keras.losses.Reduction.NONE) + return loss_fn(labels, logits) + + +class TFMaskedLanguageModelingLoss(TFCausalLanguageModelingLoss): + """ + Loss function suitable for masked language modeling (MLM), that is, the task of guessing the masked tokens. + + + + Any label of -100 will be ignored (along with the corresponding logits) in the loss computation. + + + """ + + +class TFNextSentencePredictionLoss: + """ + Loss function suitable for next sentence prediction (NSP), that is, the task of guessing the next sentence. + + + + Any label of -100 will be ignored (along with the corresponding logits) in the loss computation. + + + """ + + def hf_compute_loss(self, labels, logits): + loss_fn = keras.losses.SparseCategoricalCrossentropy(from_logits=True, reduction=keras.losses.Reduction.NONE) + if self.config.tf_legacy_loss: + # make sure only labels that are not equal to -100 + # are taken into account as loss + next_sentence_active_loss = tf.not_equal(tf.reshape(labels, (-1,)), -100) + next_sentence_reduced_logits = tf.boolean_mask(tf.reshape(logits, (-1, 2)), next_sentence_active_loss) + next_sentence_label = tf.boolean_mask(tf.reshape(labels, (-1,)), next_sentence_active_loss) + + return loss_fn(next_sentence_label, next_sentence_reduced_logits) + + # make sure only labels that are not equal to -100 + # are taken into account as loss + + # Clip negative labels to zero here to avoid NaNs and errors - those positions will get masked later anyway + unmasked_ns_loss = loss_fn(y_true=tf.nn.relu(labels), y_pred=logits) + ns_loss_mask = tf.cast(labels != -100, dtype=unmasked_ns_loss.dtype) + # Just zero out samples where label is -100, no reduction + masked_ns_loss = unmasked_ns_loss * ns_loss_mask + + return masked_ns_loss + + +def booleans_processing(config, **kwargs): + """ + Process the input booleans of each model. + + Args: + config ([`PretrainedConfig`]): + The config of the running model. + **kwargs: + The boolean parameters + + Returns: + A dictionary with the proper values for each boolean + """ + final_booleans = {} + + # Pure conv models (such as ConvNext) do not have `output_attentions`. If the signature has + # `output_attentions`, it will be present here in `kwargs`, even if unset (in that case, as `None`) + if "output_attentions" in kwargs: + final_booleans["output_attentions"] = ( + kwargs["output_attentions"] if kwargs["output_attentions"] is not None else config.output_attentions + ) + final_booleans["output_hidden_states"] = ( + kwargs["output_hidden_states"] if kwargs["output_hidden_states"] is not None else config.output_hidden_states + ) + final_booleans["return_dict"] = kwargs["return_dict"] if kwargs["return_dict"] is not None else config.return_dict + + if "use_cache" in kwargs: + final_booleans["use_cache"] = ( + kwargs["use_cache"] if kwargs["use_cache"] is not None else getattr(config, "use_cache", None) + ) + return final_booleans + + +def unpack_inputs(func): + """ + Decorator that processes the inputs to a Keras layer, passing them to the layer as keyword arguments. This enables + downstream use of the inputs by their variable name, even if they arrive packed as a dictionary in the first input + (common case in Keras). + + Args: + func (`callable`): + The callable function of the TensorFlow model. + + + Returns: + A callable that wraps the original `func` with the behavior described above. + """ + + original_signature = inspect.signature(func) + + @functools.wraps(func) + def run_call_with_unpacked_inputs(self, *args, **kwargs): + # isolates the actual `**kwargs` for the decorated function + kwargs_call = {key: val for key, val in kwargs.items() if key not in dict(original_signature.parameters)} + fn_args_and_kwargs = {key: val for key, val in kwargs.items() if key not in kwargs_call} + fn_args_and_kwargs.update({"kwargs_call": kwargs_call}) + + # move any arg into kwargs, if they exist + fn_args_and_kwargs.update(dict(zip(func.__code__.co_varnames[1:], args))) + + # Encoder Decoder models delegate the application of the configuration options to their inner models. + if "EncoderDecoder" in self.__class__.__name__: + config = None + else: + config = self.config + + unpacked_inputs = input_processing(func, config, **fn_args_and_kwargs) + return func(self, **unpacked_inputs) + + # Keras enforces the first layer argument to be passed, and checks it through `inspect.getfullargspec()`. This + # function does not follow wrapper chains (i.e. ignores `functools.wraps()`), meaning that without the line below + # Keras would attempt to check the first argument against the literal signature of the wrapper. + run_call_with_unpacked_inputs.__signature__ = original_signature + + return run_call_with_unpacked_inputs + + +def input_processing(func, config, **kwargs): + """ + Process the input of each TensorFlow model including the booleans. In case of a list of symbolic inputs, each input + has to be named accordingly to the parameters name, i.e. `input_ids = keras.Input(shape=(128,), dtype='int32', + name="input_ids")` otherwise the order of the tensors will not be guaranteed during the training. + + Args: + func (`callable`): + The callable function of the TensorFlow model. + config ([`PretrainedConfig`]): + The config of the running model. + **kwargs: + The inputs of the model. + + Returns: + Two lists, one for the missing layers, and another one for the unexpected layers. + """ + signature = dict(inspect.signature(func).parameters) + has_kwargs = bool(signature.pop("kwargs", None)) + signature.pop("self", None) + parameter_names = list(signature.keys()) + main_input_name = parameter_names[0] + main_input = kwargs.pop(main_input_name, None) + output = {} + allowed_types = (tf.Tensor, bool, int, ModelOutput, tuple, list, dict, np.ndarray) + + if "inputs" in kwargs["kwargs_call"]: + warnings.warn( + "The `inputs` argument is deprecated and will be removed in a future version, use `input_ids` instead.", + FutureWarning, + ) + + output["input_ids"] = kwargs["kwargs_call"].pop("inputs") + + if "decoder_cached_states" in kwargs["kwargs_call"]: + warnings.warn( + "The `decoder_cached_states` argument is deprecated and will be removed in a future version, use" + " `past_key_values` instead.", + FutureWarning, + ) + output["past_key_values"] = kwargs["kwargs_call"].pop("decoder_cached_states") + + if "past" in kwargs["kwargs_call"] and "past_key_values" in parameter_names: + warnings.warn( + "The `past` argument is deprecated and will be removed in a future version, use `past_key_values`" + " instead.", + FutureWarning, + ) + kwargs["past_key_values"] = kwargs["kwargs_call"].pop("past") + elif "past_key_values" in kwargs["kwargs_call"] and "past" in parameter_names: + kwargs["past"] = kwargs["kwargs_call"].pop("past_key_values") + + if has_kwargs: + output["kwargs"] = kwargs.pop("kwargs_call", {}) + else: + if len(kwargs["kwargs_call"]) > 0: + raise ValueError( + "The following keyword arguments are not supported by this model:" + f" {list(kwargs['kwargs_call'].keys())}." + ) + kwargs.pop("kwargs_call") + + for k, v in kwargs.items(): + if isinstance(v, allowed_types) or tf.is_tensor(v) or v is None: + output[k] = v + else: + raise ValueError(f"Data of type {type(v)} is not allowed only {allowed_types} is accepted for {k}.") + + if isinstance(main_input, (tuple, list)): + for i, input in enumerate(main_input): + # EagerTensors don't allow to use the .name property so we check for a real Tensor + if is_tf_symbolic_tensor(input): + # Tensor names have always the pattern `name:id` then we check only the + # `name` part + tensor_name = input.name.split(":")[0] + + if tensor_name in parameter_names: + output[tensor_name] = input + else: + output[parameter_names[i]] = input + elif isinstance(input, allowed_types) or input is None: + output[parameter_names[i]] = input + else: + raise ValueError( + f"Data of type {type(input)} is not allowed only {allowed_types} is accepted for" + f" {parameter_names[i]}." + ) + elif isinstance(main_input, Mapping): + if "inputs" in main_input: + warnings.warn( + "The `inputs` argument is deprecated and will be removed in a future version, use `input_ids`" + " instead.", + FutureWarning, + ) + + output["input_ids"] = main_input.pop("inputs") + + if "decoder_cached_states" in main_input: + warnings.warn( + "The `decoder_cached_states` argument is deprecated and will be removed in a future version, use" + " `past_key_values` instead.", + FutureWarning, + ) + output["past_key_values"] = main_input.pop("decoder_cached_states") + + for k, v in dict(main_input).items(): + if isinstance(v, allowed_types) or v is None: + output[k] = v + elif k not in parameter_names and "args" not in parameter_names: + logger.warning( + f"The parameter {k} does not belongs to the parameter list {parameter_names} and will be ignored." + ) + continue + else: + raise ValueError(f"Data of type {type(v)} is not allowed only {allowed_types} is accepted for {k}.") + else: + if tf.is_tensor(main_input) or main_input is None: + output[main_input_name] = main_input + else: + raise ValueError( + f"Data of type {type(main_input)} is not allowed only {allowed_types} is accepted for" + f" {main_input_name}." + ) + + # Populates any unspecified argument with their default value, according to the signature. + for name in parameter_names: + if name not in list(output.keys()) and name != "args": + output[name] = kwargs.pop(name, signature[name].default) + + # When creating a SavedModel TF calls the method with LayerCall.__call__(args, **kwargs) + # So to respect the proper output we have to add this exception + if "args" in output: + if output["args"] is not None and is_tf_symbolic_tensor(output["args"]): + tensor_name = output["args"].name.split(":")[0] + output[tensor_name] = output["args"] + else: + # `args` in this case is always the first parameter, then `input_ids` + output["input_ids"] = output["args"] + + del output["args"] + + if "kwargs" in output: + del output["kwargs"] + + cast_output = {} + for key, val in output.items(): + if isinstance(val, tf.Tensor) and val.dtype == tf.int64: + cast_output[key] = tf.cast(val, tf.int32) + elif isinstance(val, np.ndarray) and val.dtype == np.int64: + cast_output[key] = val.astype(np.int32) + else: + cast_output[key] = val + + output = cast_output + del cast_output + + if config is not None: + boolean_dict = { + k: v + for k, v in output.items() + if k in ["return_dict", "output_attentions", "output_hidden_states", "use_cache"] + } + + output.update( + booleans_processing( + config=config, + **boolean_dict, + ) + ) + + return output + + +def dtype_byte_size(dtype): + """ + Returns the size (in bytes) occupied by one parameter of type `dtype`. + + Example: + + ```py + >>> dtype_byte_size(tf.float32) + 4 + ``` + """ + if dtype == tf.bool: + return 1 / 8 + bit_search = re.search(r"[^\d](\d+)$", dtype.name) + if bit_search is None: + raise ValueError(f"`dtype` is not a valid dtype: {dtype}.") + bit_size = int(bit_search.groups()[0]) + return bit_size // 8 + + +def strip_model_name_and_prefix(name, _prefix=None): + if _prefix is not None and name.startswith(_prefix): + name = name[len(_prefix) :] + if name.startswith("/"): + name = name[1:] + if "model." not in name and len(name.split("/")) > 1: + name = "/".join(name.split("/")[1:]) + return name + + +def tf_shard_checkpoint(weights, max_shard_size="10GB", weights_name: str = TF2_WEIGHTS_NAME): + """ + Splits a model state dictionary in sub-checkpoints so that the final size of each sub-checkpoint does not exceed a + given size. + + The sub-checkpoints are determined by iterating through the `state_dict` in the order of its keys, so there is no + optimization made to make each sub-checkpoint as close as possible to the maximum size passed. For example, if the + limit is 10GB and we have weights of sizes [6GB, 6GB, 2GB, 6GB, 2GB, 2GB] they will get sharded as [6GB], [6+2GB], + [6+2+2GB] and not [6+2+2GB], [6+2GB], [6GB]. + + + + If one of the model's weight is bigger that `max_shard_size`, it will end up in its own sub-checkpoint which will + have a size greater than `max_shard_size`. + + + + Args: + weights (`Dict[str, tf.RessourceVariable]`): The list of tf.RessourceVariable of a model to save. + max_shard_size (`int` or `str`, *optional*, defaults to `"10GB"`): + The maximum size of each sub-checkpoint. If expressed as a string, needs to be digits followed by a unit + (like `"5MB"`). + """ + max_shard_size = convert_file_size_to_int(max_shard_size) + + sharded_state_dicts = [] + current_block = [] + current_block_size = 0 + total_size = 0 + + for item in weights: + weight_size = item.numpy().size * dtype_byte_size(item.dtype) + + # If this weight is going to tip up over the maximal size, we split. + if current_block_size + weight_size > max_shard_size: + sharded_state_dicts.append(current_block) + current_block = [] + current_block_size = 0 + + current_block.append(item) + current_block_size += weight_size + total_size += weight_size + + # Add the last block + sharded_state_dicts.append(current_block) + + # If we only have one shard, we return it + if len(sharded_state_dicts) == 1: + return {weights_name: sharded_state_dicts[0]}, None + + # Otherwise, let's build the index + weight_map = {} + shards = {} + for idx, shard in enumerate(sharded_state_dicts): + shard_file = weights_name.replace(".h5", f"-{idx+1:05d}-of-{len(sharded_state_dicts):05d}.h5") + shard_file = shard_file.replace( + ".safetensors", f"-{idx + 1:05d}-of-{len(sharded_state_dicts):05d}.safetensors" + ) + shards[shard_file] = shard + for weight in shard: + weight_name = weight.name + weight_map[weight_name] = shard_file + + # Add the metadata + metadata = {"total_size": total_size} + index = {"metadata": metadata, "weight_map": weight_map} + return shards, index + + +def load_tf_sharded_weights(model, shard_files, ignore_mismatched_sizes=False, strict=False, _prefix=None): + """ + This is the same as `load_tf_weights` but for a sharded checkpoint. Detect missing and unexpected layers and load + the TF weights from the shard file accordingly to their names and shapes. + + This load is performed efficiently: each checkpoint shard is loaded one by one in RAM and deleted after being + loaded in the model. + + Args: + model (`keras.models.Model`): The model in which to load the checkpoint. + shard_files (`str` or `os.PathLike`): A list containing the sharded checkpoint names. + ignore_mismatched_sizes`bool`, *optional`, defaults to `True`): + Whether or not to ignore the mismatch between the sizes + strict (`bool`, *optional*, defaults to `True`): + Whether to strictly enforce that the keys in the model state dict match the keys in the sharded checkpoint. + + Returns: + Three lists, one for the missing layers, another one for the unexpected layers, and a last one for the + mismatched layers. + """ + + # Load the index + unexpected_keys = set() + saved_keys = set() + mismatched_keys = set() + + # Since TF adds the name of the class to its weights, and uses the index and not the name of the layer to load + # the weight, we have to get rid of the first prefix of the name of the layer. + model_keys = set() + model_layer_map = {} + for i, k in enumerate(model.weights): + layer_name = k.name + if _prefix is not None and layer_name.startswith(_prefix): + layer_name = layer_name[len(_prefix) :] + layer_name = layer_name.lstrip("/") + if not ("model." in layer_name or len(layer_name.split("/")) == 1): + layer_name = "/".join(layer_name.split("/")[1:]) + model_keys.add(layer_name) + model_layer_map[layer_name] = i + + for shard_file in shard_files: + saved_weight_names_set, unexpected_keys_set, mismatched_keys_set = load_tf_shard( + model, + model_layer_map, + shard_file, + ignore_mismatched_sizes=ignore_mismatched_sizes, + _prefix=_prefix, + ) + saved_keys.update(saved_weight_names_set) + unexpected_keys.update(unexpected_keys_set) + mismatched_keys.update(mismatched_keys_set) + gc.collect() + + missing_keys = model_keys - saved_keys + if strict and (len(missing_keys) > 0 or len(unexpected_keys) > 0): + error_message = f"Error(s) in loading state_dict for {model.__class__.__name__}" + if len(missing_keys) > 0: + str_missing_keys = ",".join([f'"{k}"' for k in missing_keys]) + error_message += f"\nMissing key(s): {str_missing_keys}." + if len(unexpected_keys) > 0: + str_unexpected_keys = ",".join([f'"{k}"' for k in unexpected_keys]) + error_message += f"\nMissing key(s): {str_unexpected_keys}." + raise RuntimeError(error_message) + + return missing_keys, unexpected_keys, mismatched_keys + + +def load_tf_shard(model, model_layer_map, resolved_archive_file, ignore_mismatched_sizes=False, _prefix=None): + """ + Loads a shard from a sharded checkpoint file. Can be either H5 or Safetensors. + Handles missing keys and unexpected keys. + + Args: + model (`keras.models.Model`): Model in which the weights are loaded + model_layer_map (`Dict`): A dictionary mapping the layer name to the index of the layer in the model. + resolved_archive_file (`str`): Path to the checkpoint file from which the weights will be loaded + ignore_mismatched_sizes (`bool`, *optional*, defaults to `False`): Whether to ignore the mismatched keys + + Returns: + `keras.models.Model`: Three lists, one for the layers that were found and succesfully restored (from the + shard file), one for the mismatched layers, and another one for the unexpected layers. + """ + saved_weight_names_set = set() + saved_weights = {} + mismatched_keys = set() + unexpected_keys = set() + # Read the H5 file + try: + with h5py.File(resolved_archive_file, "r") as sharded_checkpoint_file: + # Retrieve the name of each layer from the H5 file + saved_h5_model_layers_name = set(load_attributes_from_hdf5_group(sharded_checkpoint_file, "layer_names")) + weight_value_tuples = [] + + # Compute missing and unexpected sub layers + # Store the weights in list of tuples that looks like [(weight_object, value_of_weight),...] + for layer_name in saved_h5_model_layers_name: + h5_layer_object = sharded_checkpoint_file[layer_name] + saved_weights[layer_name] = np.asarray(h5_layer_object) + + saved_weight_names_set.add(layer_name) + + if layer_name not in model_layer_map: + unexpected_keys.add(layer_name) + else: + symbolic_weight = model.weights[model_layer_map[layer_name]] + + saved_weight_value = saved_weights[layer_name] + # If the current weight is found + if saved_weight_value is not None: + # Check if the shape of the current weight and the one from the H5 file are different + if K.int_shape(symbolic_weight) != saved_weight_value.shape: + # If yes we reshape the weight from the H5 file accordingly to the current weight + # If the two shapes are not compatible we raise an issue + try: + array = np.reshape(saved_weight_value, K.int_shape(symbolic_weight)) + except ValueError as e: + if ignore_mismatched_sizes: + mismatched_keys.add( + (layer_name, saved_weight_value.shape, K.int_shape(symbolic_weight)) + ) + continue + else: + raise e + else: + array = saved_weight_value + + # We create the tuple that will be loaded and add it to the final list + weight_value_tuples.append((symbolic_weight, array)) + + K.batch_set_value(weight_value_tuples) + + return saved_weight_names_set, unexpected_keys, mismatched_keys + + except Exception as e: + try: + with open(resolved_archive_file) as f: + if f.read().startswith("version"): + raise OSError( + "You seem to have cloned a repository without having git-lfs installed. Please install " + "git-lfs and run `git lfs install` followed by `git lfs pull` in the folder " + "you cloned." + ) + else: + raise ValueError( + f"Unable to locate the file {resolved_archive_file} which is necessary to load this pretrained" + " model. Make sure you have saved the model properly." + ) from e + except (UnicodeDecodeError, ValueError): + raise OSError( + f"Unable to load weights from TF checkpoint file for '{resolved_archive_file}' " + f"at '{resolved_archive_file}'. " + "If you tried to load a TF model from a sharded checkpoint, you should try converting the model " + "by loading it in pytorch and saving it localy. A convertion script should be realeased soon." + ) + + +def load_tf_sharded_weights_from_safetensors( + model, shard_files, ignore_mismatched_sizes=False, strict=False, _prefix=None +): + """ + This is the same as `load_tf_weights_from_safetensors` but for a sharded TF-format safetensors checkpoint. + Detect missing and unexpected layers and load the TF weights from the shard file accordingly to their names and + shapes. + + This load is performed efficiently: each checkpoint shard is loaded one by one in RAM and deleted after being + loaded in the model. + + Args: + model (`keras.models.Model`): The model in which to load the checkpoint. + shard_files (`str` or `os.PathLike`): A list containing the sharded checkpoint names. + ignore_mismatched_sizes`bool`, *optional`, defaults to `True`): + Whether or not to ignore the mismatch between the sizes + strict (`bool`, *optional*, defaults to `True`): + Whether to strictly enforce that the keys in the model state dict match the keys in the sharded checkpoint. + + Returns: + Three lists, one for the missing layers, another one for the unexpected layers, and a last one for the + mismatched layers. + """ + + # Load the index + unexpected_keys = set() + all_missing_keys = [] + mismatched_keys = set() + + for shard_file in shard_files: + missing_layers, unexpected_layers, mismatched_layers = load_tf_weights_from_safetensors( + model, + shard_file, + ignore_mismatched_sizes=ignore_mismatched_sizes, + _prefix=_prefix, + ) + all_missing_keys.append(set(missing_layers)) + unexpected_keys.update(unexpected_layers) + mismatched_keys.update(mismatched_layers) + gc.collect() + missing_keys = set.intersection(*all_missing_keys) + + if strict and (len(missing_keys) > 0 or len(unexpected_keys) > 0): + error_message = f"Error(s) in loading state_dict for {model.__class__.__name__}" + if len(missing_keys) > 0: + str_missing_keys = ",".join([f'"{k}"' for k in missing_keys]) + error_message += f"\nMissing key(s): {str_missing_keys}." + if len(unexpected_keys) > 0: + str_unexpected_keys = ",".join([f'"{k}"' for k in unexpected_keys]) + error_message += f"\nMissing key(s): {str_unexpected_keys}." + raise RuntimeError(error_message) + + return missing_keys, unexpected_keys, mismatched_keys + + +def load_tf_weights(model, resolved_archive_file, ignore_mismatched_sizes=False, _prefix=None): + """ + Detect missing and unexpected layers and load the TF weights from the shard file accordingly to their names and + shapes. + + Args: + model (`keras.models.Model`): + The model to load the weights into. + resolved_archive_file (`str`): + The location of the H5 file. + ignore_mismatched_sizes (`bool`, *optional*, defaults to `False`): + Whether or not to ignore weights with shapes that don't match between the checkpoint of the model. + + Returns: + Three lists, one for the missing layers, another one for the unexpected layers, and a last one for the + mismatched layers. + """ + if resolved_archive_file.endswith(".safetensors"): + load_function = load_tf_weights_from_safetensors + else: + load_function = load_tf_weights_from_h5 + + return load_function( + model, resolved_archive_file, ignore_mismatched_sizes=ignore_mismatched_sizes, _prefix=_prefix + ) + + +def load_tf_weights_from_h5(model, resolved_archive_file, ignore_mismatched_sizes=False, _prefix=None): + mismatched_layers = [] + + # Read the H5 file + with h5py.File(resolved_archive_file, "r") as sharded_checkpoint_file: + # Retrieve the name of each layer from the H5 file + saved_h5_model_layers_name = set(load_attributes_from_hdf5_group(sharded_checkpoint_file, "layer_names")) + + # Find the missing layers from the high level list of layers + missing_layers = list({layer.name for layer in model.layers} - saved_h5_model_layers_name) + + # Find the unexpected layers from the high level list of layers + unexpected_layers = list(saved_h5_model_layers_name - {layer.name for layer in model.layers}) + saved_weight_names_set = set() + symbolic_weights_names = set() + weight_value_tuples = [] + + # Compute missing and unexpected sub layers + # Store the weights in list of tuples that looks like [(weight_object, value_of_weight),...] + for layer in model.layers: + # if layer_name from the H5 file belongs to the layers from the instantiated model + if layer.name in saved_h5_model_layers_name: + # Get the H5 layer object from its name + h5_layer_object = sharded_checkpoint_file[layer.name] + # Get all the weights as a list from the layer object + symbolic_weights = layer.trainable_weights + layer.non_trainable_weights + saved_weights = {} + + # Create a dict from the H5 saved model that looks like {"weight_name": weight_value} + # And a set with only the names + for weight_name in load_attributes_from_hdf5_group(h5_layer_object, "weight_names"): + # TF names always start with the model name so we ignore it + name = "/".join(weight_name.split("/")[1:]) + + if _prefix is not None: + name = _prefix + "/" + name + + saved_weights[name] = np.asarray(h5_layer_object[weight_name]) + + # Add the updated name to the final list for computing missing/unexpected values + saved_weight_names_set.add(name) + + # Loop over each weights from the instantiated model and compare with the weights from the H5 file + for symbolic_weight in symbolic_weights: + # TF names always start with the model name so we ignore it + if _prefix is not None: + delimeter = len(_prefix.split("/")) + symbolic_weight_name = "/".join( + symbolic_weight.name.split("/")[:delimeter] + + symbolic_weight.name.split("/")[delimeter + 1 :] + ) + else: + symbolic_weight_name = "/".join(symbolic_weight.name.split("/")[1:]) + + # here we check if the current weight is among the weights from the H5 file + # If yes, get the weight_value of the corresponding weight from the H5 file + # If not, make the value to None + saved_weight_value = saved_weights.get(symbolic_weight_name, None) + + # Retrocompatibility patch: some embeddings are stored with the weights name (e.g. Bart's + # `model.shared/embeddings:0` are stored as `model.shared/weights:0`) + if saved_weight_value is None and symbolic_weight_name.endswith("embeddings:0"): + symbolic_weight_name = symbolic_weight_name[:-12] + "weight:0" + saved_weight_value = saved_weights.get(symbolic_weight_name, None) + + # Add the updated name to the final list for computing missing/unexpected values + symbolic_weights_names.add(symbolic_weight_name) + + # If the current weight is found + if saved_weight_value is not None: + # Check if the shape of the current weight and the one from the H5 file are different + if K.int_shape(symbolic_weight) != saved_weight_value.shape: + # If yes we reshape the weight from the H5 file accordingly to the current weight + # If the two shapes are not compatible we raise an issue + try: + array = np.reshape(saved_weight_value, K.int_shape(symbolic_weight)) + except ValueError as e: + if ignore_mismatched_sizes: + mismatched_layers.append( + (symbolic_weight_name, saved_weight_value.shape, K.int_shape(symbolic_weight)) + ) + continue + else: + raise e + else: + array = saved_weight_value + + # We create the tuple that will be loaded and add it to the final list + weight_value_tuples.append((symbolic_weight, array)) + + # Load all the weights + K.batch_set_value(weight_value_tuples) + + # Compute the missing and unexpected layers + missing_layers.extend(list(symbolic_weights_names - saved_weight_names_set)) + unexpected_layers.extend(list(saved_weight_names_set - symbolic_weights_names)) + + return missing_layers, unexpected_layers, mismatched_layers + + +def load_tf_weights_from_safetensors(model, resolved_archive_file, ignore_mismatched_sizes=False, _prefix=None): + # Read the safetensors file + with safe_open(resolved_archive_file, framework="tf") as safetensors_archive: + mismatched_layers = [] + weight_names = [strip_model_name_and_prefix(w.name, _prefix=_prefix) for w in model.weights] + loaded_weight_names = list(safetensors_archive.keys()) + # Find the missing layers from the high level list of layers + missing_layers = list(set(weight_names) - set(loaded_weight_names)) + # Find the unexpected layers from the high level list of layers + unexpected_layers = list(set(loaded_weight_names) - set(weight_names)) + + for weight in model.weights: + weight_name = strip_model_name_and_prefix(weight.name, _prefix=_prefix) + if weight_name in loaded_weight_names: + weight_value = safetensors_archive.get_tensor(weight_name) + # Check if the shape of the current weight and the one from the H5 file are different + if K.int_shape(weight) != weight_value.shape: + # If yes we reshape the weight from the H5 file accordingly to the current weight + # If the two shapes are not compatible we raise an issue + try: + weight_value = tf.reshape(weight_value, K.int_shape(weight)) + except (ValueError, tf.errors.InvalidArgumentError) as e: + if ignore_mismatched_sizes: + mismatched_layers.append((weight_name, weight_value.shape, K.int_shape(weight))) + continue + else: + raise e + + K.set_value(weight, weight_value) # weight.assign() might break if weight is a DTensor + return missing_layers, unexpected_layers, mismatched_layers + + +def init_copy_embeddings(old_embeddings, new_num_tokens): + r""" + This function aims to reduce the embeddings in case new_num_tokens < old_num_tokens or to pad with -1 in case + new_num_tokens > old_num_tokens. A mask is also computed in order to know which weight in the embeddings should be + kept or not. Example: + + - if new_num_tokens=5 and old_num_tokens=4 and old_embeddings=[w1,w2,w3,w4] + + - mask=[True,True,True,True,False] and current_weights=[w1,w2,w3,w4,-1] + - if new_num_tokens=4 and old_num_tokens=5 and old_embeddings=[w1,w2,w3,w4,w5] + + - mask=[True,True,True,True] and current_weights=[w1,w2,w3,w4] + """ + old_num_tokens, old_embedding_dim = shape_list(old_embeddings) + size_diff = new_num_tokens - old_num_tokens + + # initialize new embeddings + # Copy token embeddings from the previous ones + if tf.math.greater(size_diff, 0): + # if the new size is greater than the old one, we extend the current embeddings with a padding until getting new size + # and we create a mask to properly identify the padded values and be replaced by the values of the newly created + # embeddings + current_weights = tf.pad( + old_embeddings.value(), tf.convert_to_tensor([[0, size_diff], [0, 0]]), constant_values=-1 + ) + num_tokens_to_copy = min(old_num_tokens, new_num_tokens) + mask = tf.fill(tf.convert_to_tensor([num_tokens_to_copy, 1]), True) + mask = tf.pad(mask, tf.convert_to_tensor([[0, size_diff], [0, 0]]), constant_values=False) + else: + # if the new size if lower than the old one, we take the current embeddings until the new size + current_weights = tf.slice( + old_embeddings.value(), + tf.convert_to_tensor([0, 0]), + tf.convert_to_tensor([new_num_tokens, old_embedding_dim]), + ) + mask = tf.fill(tf.convert_to_tensor([new_num_tokens, 1]), True) + + return mask, current_weights + + +class TFPreTrainedModel(keras.Model, TFModelUtilsMixin, TFGenerationMixin, PushToHubMixin): + r""" + Base class for all TF models. + + [`TFPreTrainedModel`] takes care of storing the configuration of the models and handles methods for loading, + downloading and saving models as well as a few methods common to all models to: + + - resize the input embeddings, + - prune heads in the self-attention heads. + + Class attributes (overridden by derived classes): + + - **config_class** ([`PretrainedConfig`]) -- A subclass of [`PretrainedConfig`] to use as configuration class + for this model architecture. + - **base_model_prefix** (`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. + - **main_input_name** (`str`) -- The name of the principal input to the model (often `input_ids` for NLP + models, `pixel_values` for vision models and `input_values` for speech models). + """ + + config_class = None + base_model_prefix = "" + main_input_name = "input_ids" + _auto_class = None + _using_dummy_loss = None + _label_to_output_map = None + + # a list of re pattern of tensor names to ignore from the model when loading the model weights + # (and avoid unnecessary warnings). + _keys_to_ignore_on_load_missing = None + # a list of re pattern of tensor names to ignore from the weights when loading the model weights + # (and avoid unnecessary warnings). + _keys_to_ignore_on_load_unexpected = None + _requires_load_weight_prefix = False + + @property + def dummy_inputs(self) -> Dict[str, tf.Tensor]: + """ + Dummy inputs to build the network. + + Returns: + `Dict[str, tf.Tensor]`: The dummy inputs. + """ + dummies = {} + for key, spec in self.input_signature.items(): + # 2 is the most correct arbitrary size. I will not be taking questions + dummy_shape = [dim if dim is not None else 2 for dim in spec.shape] + if spec.shape[0] is None: + # But let's make the batch size 1 to save memory anyway + dummy_shape[0] = 1 + dummies[key] = tf.ones(shape=dummy_shape, dtype=spec.dtype) + if key == "token_type_ids": + # Some models have token_type_ids but with a vocab_size of 1 + dummies[key] = tf.zeros_like(dummies[key]) + if self.config.add_cross_attention and "encoder_hidden_states" in inspect.signature(self.call).parameters: + if "encoder_hidden_states" not in dummies: + if self.main_input_name == "input_ids": + dummies["encoder_hidden_states"] = tf.ones( + shape=(1, 2, self.config.hidden_size), dtype=tf.float32, name="encoder_hidden_states" + ) + else: + raise NotImplementedError( + "Model has cross-attention but we couldn't infer the shape for the encoder hidden states. Please manually override dummy_inputs!" + ) + return dummies + + def build_in_name_scope(self): + with tf.name_scope(self.name): + self.build(input_shape=None) + + @property + def framework(self) -> str: + """ + :str: Identifies that this is a TensorFlow model. + """ + return "tf" + + def build(self, input_shape=None): + pass # This is just here to make sure we don't call the superclass build() + + def __init__(self, config, *inputs, **kwargs): + super().__init__(*inputs, **kwargs) + if not isinstance(config, PretrainedConfig): + raise ValueError( + f"Parameter config in `{self.__class__.__name__}(config)` should be an instance of class " + "`PretrainedConfig`. To create a model from a pretrained model use " + f"`model = {self.__class__.__name__}.from_pretrained(PRETRAINED_MODEL_NAME)`" + ) + # Save config and origin of the pretrained weights if given in model + self.config = config + self.name_or_path = config.name_or_path + self.generation_config = GenerationConfig.from_model_config(config) if self.can_generate() else None + self._set_save_spec(self.input_signature) + + def get_config(self): + return self.config.to_dict() + + @functools.wraps(keras.Model.fit) + def fit(self, *args, **kwargs): + args, kwargs = convert_batch_encoding(*args, **kwargs) + return super().fit(*args, **kwargs) + + @functools.wraps(keras.Model.train_on_batch) + def train_on_batch(self, *args, **kwargs): + args, kwargs = convert_batch_encoding(*args, **kwargs) + return super().train_on_batch(*args, **kwargs) + + @functools.wraps(keras.Model.test_on_batch) + def test_on_batch(self, *args, **kwargs): + args, kwargs = convert_batch_encoding(*args, **kwargs) + return super().test_on_batch(*args, **kwargs) + + @functools.wraps(keras.Model.predict_on_batch) + def predict_on_batch(self, *args, **kwargs): + args, kwargs = convert_batch_encoding(*args, **kwargs) + return super().predict_on_batch(*args, **kwargs) + + @functools.wraps(keras.Model.predict) + def predict(self, *args, **kwargs): + args, kwargs = convert_batch_encoding(*args, **kwargs) + return super().predict(*args, **kwargs) + + @functools.wraps(keras.Model.evaluate) + def evaluate(self, *args, **kwargs): + args, kwargs = convert_batch_encoding(*args, **kwargs) + return super().evaluate(*args, **kwargs) + + @classmethod + def from_config(cls, config, **kwargs): + if isinstance(config, PretrainedConfig): + return cls._from_config(config, **kwargs) + return cls._from_config(cls.config_class.from_dict(config, **kwargs)) + + @classmethod + def _from_config(cls, config, **kwargs): + """ + All context managers that the model should be initialized under go here. + """ + return cls(config, **kwargs) + + def get_head_mask(self, head_mask: tf.Tensor | None, num_hidden_layers: int) -> tf.Tensor: + """ + Prepare the head mask if needed. + + Args: + head_mask (`tf.Tensor` with shape `[num_heads]` or `[num_hidden_layers x num_heads]`, *optional*): + The mask indicating if we should keep the heads or not (1.0 for keep, 0.0 for discard). + num_hidden_layers (`int`): + The number of hidden layers in the model. + + Returns: + `tf.Tensor` with shape `[num_hidden_layers x batch x num_heads x seq_length x seq_length]` or list with + `[None]` for each layer. + """ + if head_mask is not None: + head_mask = self._convert_head_mask_to_5d(head_mask, num_hidden_layers) + else: + head_mask = [None] * num_hidden_layers + + return head_mask + + def _convert_head_mask_to_5d(self, head_mask, num_hidden_layers): + """-> [num_hidden_layers x batch x num_heads x seq_length x seq_length]""" + if head_mask.shape.rank == 1: + head_mask = head_mask[None, None, :, None, None] + head_mask = tf.repeat(head_mask, repeats=num_hidden_layers, axis=0) + elif head_mask.shape.rank == 2: + head_mask = head_mask[:, None, :, None, None] + assert head_mask.shape.rank == 5, f"head_mask.dim != 5, instead {head_mask.dim()}" + head_mask = tf.cast(head_mask, tf.float32) # switch to float if need + fp16 compatibility + return head_mask + + @tf.function + def serving(self, inputs): + """ + Args: + Method used for serving the model. Does not have a specific signature, but will be specialized as concrete + functions when saving with `save_pretrained`. + inputs (`Dict[str, tf.Tensor]`): + The input of the saved model as a dictionary of tensors. + """ + output = self.call(inputs) + + return self.serving_output(output) + + @property + def input_signature(self) -> Dict[str, tf.TensorSpec]: + """ + This property should return a dict mapping input names to tf.TensorSpec objects, representing the expected + shape and dtype for model inputs. It is used for both serving and for generating dummy inputs. + """ + model_inputs = list(inspect.signature(self.call).parameters) + sig = {} + if "input_ids" in model_inputs: + if self.__class__.__name__.endswith("ForMultipleChoice"): + text_dims = 3 + else: + text_dims = 2 + for input_name in ( + "input_ids", + "attention_mask", + "token_type_ids", + "decoder_input_ids", + "decoder_attention_mask", + ): + if input_name in model_inputs: + sig[input_name] = tf.TensorSpec([None] * text_dims, tf.int32, name=input_name) + if "pixel_values" in model_inputs: + pixel_values_shape = [None, None, None, None] + if hasattr(self.config, "vision_config"): + vision_config = self.config.vision_config + else: + vision_config = self.config + if hasattr(vision_config, "num_channels"): + pixel_values_shape[1] = vision_config.num_channels + else: + raise NotImplementedError( + "Could not infer number of channels from config, please override input_signature to specify input shapes." + ) + if hasattr(vision_config, "image_size"): + pixel_values_shape[2] = pixel_values_shape[3] = vision_config.image_size + elif hasattr(vision_config, "input_size"): + pixel_values_shape[2] = pixel_values_shape[3] = vision_config.input_size + else: + raise NotImplementedError( + "Could not infer input image shape from config, please override input_signature to specify input shapes." + ) + sig["pixel_values"] = tf.TensorSpec(pixel_values_shape, tf.float32, name="pixel_values") + if "input_features" in model_inputs: + raise NotImplementedError("Audio models need a manually defined input_signature") + return sig + + def serving_output(self, output): + """ + Prepare the output of the saved model. Can be overridden if specific serving modifications are required. + """ + if not isinstance(output, ModelOutput): + return output + for key in output: + if key.endswith("hidden_states") and not getattr(self.config, "output_hidden_states", False): + output[key] = None + elif key.endswith("attentions") and not getattr(self.config, "output_attentions", False): + output[key] = None + elif key == "past_key_values" and not getattr(self.config, "use_cache", False): + output[key] = None + elif key == "cross_attentions" and not ( + getattr(self.config, "output_attentions", False) and getattr(self.config, "add_cross_attention", False) + ): + output[key] = None + if isinstance(output[key], (tuple, list)): + try: + output[key] = tf.convert_to_tensor(output[key]) + except (ValueError, tf.errors.InvalidArgumentError): + pass # Layers may not have the same dimensions + return output + + @classmethod + def can_generate(cls) -> bool: + """ + Returns whether this model can generate sequences with `.generate()`. + + Returns: + `bool`: Whether this model can generate sequences with `.generate()`. + """ + # Detects whether `prepare_inputs_for_generation` has been overwritten, which is a requirement for generation. + # Alternativelly, the model can also have a custom `generate` function. + if "GenerationMixin" in str(cls.prepare_inputs_for_generation) and "GenerationMixin" in str(cls.generate): + return False + return True + + def get_input_embeddings(self) -> keras.layers.Layer: + """ + Returns the model's input embeddings layer. + + Returns: + `tf.Variable`: The embeddings layer mapping vocabulary to hidden states. + """ + main_layer = getattr(self, self.base_model_prefix, self) + + if main_layer is not self: + return main_layer.get_input_embeddings() + else: + raise NotImplementedError + + def _save_checkpoint(self, checkpoint_dir, epoch): + if not os.path.isdir(checkpoint_dir): + os.mkdir(checkpoint_dir) + # We avoid tf.train.checkpoint or saving weights in TF format, even though that includes optimizer + # state for us, because it requires special handling for objects like custom losses, which we use + # internally and which users are likely to use too + weights_path = os.path.join(checkpoint_dir, "weights.h5") + self.save_weights(weights_path) + extra_data = {"epoch": epoch, "optimizer_state": self.optimizer.get_weights()} + extra_data_path = os.path.join(checkpoint_dir, "extra_data.pickle") + with open(extra_data_path, "wb") as f: + pickle.dump(extra_data, f) + + def prepare_tf_dataset( + self, + dataset: "datasets.Dataset", # noqa:F821 + batch_size: int = 8, + shuffle: bool = True, + tokenizer: Optional["PreTrainedTokenizerBase"] = None, + collate_fn: Optional[Callable] = None, + collate_fn_args: Optional[Dict[str, Any]] = None, + drop_remainder: Optional[bool] = None, + prefetch: bool = True, + ): + """ + Wraps a HuggingFace [`~datasets.Dataset`] as a `tf.data.Dataset` with collation and batching. This method is + designed to create a "ready-to-use" dataset that can be passed directly to Keras methods like `fit()` without + further modification. The method will drop columns from the dataset if they don't match input names for the + model. If you want to specify the column names to return rather than using the names that match this model, we + recommend using `Dataset.to_tf_dataset()` instead. + + Args: + dataset (`Any`): + A [~`datasets.Dataset`] to be wrapped as a `tf.data.Dataset`. + batch_size (`int`, defaults to 8): + The size of batches to return. + shuffle (`bool`, defaults to `True`): + Whether to return samples from the dataset in random order. Usually `True` for training datasets and + `False` for validation/test datasets. + tokenizer ([`PreTrainedTokenizerBase`], *optional*): + A `PreTrainedTokenizer` that will be used to pad samples to create batches. Has no effect if a specific + `collate_fn` is passed instead. + collate_fn (`Callable`, *optional*): + A function that collates samples from the dataset into a single batch. Defaults to + `DefaultDataCollator` if no `tokenizer` is supplied or `DataCollatorWithPadding` if a `tokenizer` is + passed. + collate_fn_args (`Dict[str, Any]`, *optional*): + A dict of arguments to pass to the `collate_fn` alongside the list of samples. + drop_remainder (`bool`, *optional*): + Whether to drop the final batch, if the batch_size does not evenly divide the dataset length. Defaults + to the same setting as `shuffle`. + prefetch (`bool`, defaults to `True`): + Whether to add prefetching to the end of the `tf.data` pipeline. This is almost always beneficial for + performance, but can be disabled in edge cases. + + + Returns: + `Dataset`: A `tf.data.Dataset` which is ready to pass to the Keras API. + """ + requires_backends(self, ["datasets"]) + import datasets + + if collate_fn is None: + if tokenizer is None: + collate_fn = DefaultDataCollator(return_tensors="np") + else: + collate_fn = DataCollatorWithPadding(tokenizer=tokenizer, return_tensors="np") + if collate_fn_args is None: + collate_fn_args = {} + + if not isinstance(dataset, datasets.Dataset): + raise TypeError("Dataset argument should be a datasets.Dataset!") + model_inputs = list(inspect.signature(self.call).parameters) + model_labels = find_labels(self.__class__) + if "cols_to_retain" in list(inspect.signature(dataset._get_output_signature).parameters.keys()): + output_signature, _ = dataset._get_output_signature( + dataset, + batch_size=None, + collate_fn=collate_fn, + collate_fn_args=collate_fn_args, + cols_to_retain=model_inputs, + ) + else: + # TODO Matt: This is a workaround for older versions of datasets that are missing the `cols_to_retain` + # argument. We should remove this once the minimum supported version of datasets is > 2.3.2 + unwanted_columns = [ + feature + for feature in dataset.features + if feature not in model_inputs and feature not in ("label_ids", "label") + ] + dataset = dataset.remove_columns(unwanted_columns) + output_signature, _ = dataset._get_output_signature( + dataset, batch_size=None, collate_fn=collate_fn, collate_fn_args=collate_fn_args + ) + output_columns = list(output_signature.keys()) + feature_cols = [col for col in output_columns if col in model_inputs and col not in model_labels] + label_cols = [col for col in output_columns if col in model_labels] + + # Backwards compatibility for older versions of datasets. Previously, if `columns` or `label_cols` + # were a single element list, the returned element spec would be a single element. Now, passing [feature] + # will return a dict structure {"feature": feature}, and passing a single string will return a single element. + feature_cols = feature_cols[0] if len(feature_cols) == 1 else feature_cols + label_cols = label_cols[0] if len(label_cols) == 1 else label_cols + + if drop_remainder is None: + drop_remainder = shuffle + tf_dataset = dataset.to_tf_dataset( + columns=feature_cols, + label_cols=label_cols, + batch_size=batch_size, + shuffle=shuffle, + drop_remainder=drop_remainder, + collate_fn=collate_fn, + collate_fn_args=collate_fn_args, + prefetch=prefetch, + ) + return tf_dataset + + def compile( + self, + optimizer="rmsprop", + loss="auto_with_warning", + metrics=None, + loss_weights=None, + weighted_metrics=None, + run_eagerly=None, + steps_per_execution=None, + **kwargs, + ): + """ + This is a thin wrapper that sets the model's loss output head as the loss if the user does not specify a loss + function themselves. + """ + if loss in ("auto_with_warning", "passthrough"): # "passthrough" for workflow backward compatibility + logger.info( + "No loss specified in compile() - the model's internal loss computation will be used as the " + "loss. Don't panic - this is a common way to train TensorFlow models in Transformers! " + "To disable this behaviour please pass a loss argument, or explicitly pass " + "`loss=None` if you do not want your model to compute a loss. You can also specify `loss='auto'` to " + "get the internal loss without printing this info string." + ) + loss = "auto" + if loss == "auto": + loss = dummy_loss + self._using_dummy_loss = True + else: + self._using_dummy_loss = False + parent_args = list(inspect.signature(keras.Model.compile).parameters.keys()) + # This argument got renamed, we need to support both versions + if "steps_per_execution" in parent_args: + super().compile( + optimizer=optimizer, + loss=loss, + metrics=metrics, + loss_weights=loss_weights, + weighted_metrics=weighted_metrics, + run_eagerly=run_eagerly, + steps_per_execution=steps_per_execution, + **kwargs, + ) + else: + super().compile( + optimizer=optimizer, + loss=loss, + metrics=metrics, + loss_weights=loss_weights, + weighted_metrics=weighted_metrics, + run_eagerly=run_eagerly, + experimental_steps_per_execution=steps_per_execution, + **kwargs, + ) + + def compute_loss(self, *args, **kwargs): + if hasattr(keras.Model, "compute_loss"): + # This will be true in TF 2.8 or greater + return super().compute_loss(*args, **kwargs) + else: + warnings.warn( + "The old compute_loss method is deprecated as it conflicts with the Keras compute_loss " + "method added in TF 2.8. If you want the original HF compute_loss, please call " + "hf_compute_loss() instead. From TF versions >= 2.8, or Transformers versions >= 5, " + "calling compute_loss() will get the Keras method instead.", + FutureWarning, + ) + return self.hf_compute_loss(*args, **kwargs) + + def get_label_to_output_name_mapping(self): + arg_names = list(inspect.signature(self.call).parameters) + if self._label_to_output_map is not None: + return self._label_to_output_map + elif "start_positions" in arg_names: + return {"start_positions": "start_logits", "end_positions": "end_logits"} + elif "sentence_order_label" in arg_names: + return {"labels": "prediction_logits", "sentence_order_label": "sop_logits"} + elif "next_sentence_label" in arg_names: + return {"labels": "prediction_logits", "next_sentence_label": "seq_relationship_logits"} + elif "mc_labels" in arg_names: + return {"labels": "logits", "mc_labels": "mc_logits"} + else: + return {} + + def train_step(self, data): + """ + A modification of Keras's default `train_step` that correctly handles matching outputs to labels for our models + and supports directly training on the loss output head. In addition, it ensures input keys are copied to the + labels where appropriate. It will also copy label keys into the input dict when using the dummy loss, to ensure + that they are available to the model during the forward pass. + """ + + # We hardcode the most common renamings; models with weirder names can set `self._label_to_output_map` + arg_names = list(inspect.signature(self.call).parameters) + label_kwargs = find_labels(self.__class__) + label_to_output = self.get_label_to_output_name_mapping() + output_to_label = {val: key for key, val in label_to_output.items()} + if not self._using_dummy_loss and parse(tf.__version__) < parse("2.11.0"): + # Newer TF train steps leave this out + data = expand_1d(data) + x, y, sample_weight = keras.utils.unpack_x_y_sample_weight(data) + # If the inputs are mutable dictionaries, make a shallow copy of them because we will modify + # them during input/label pre-processing. This avoids surprising the user by wrecking their data. + # In addition, modifying mutable Python inputs makes XLA compilation impossible. + if isinstance(x, dict): + x = x.copy() + if isinstance(y, dict): + y = y.copy() + + # When using a dummy loss, we ensure that separate labels are copied to the correct model arguments, + # if those keys are not already present in the input dict + if self._using_dummy_loss and y is not None: + # If y is a tensor and the model only has one label-like input, map y to that input + if len(label_kwargs) == 1 and isinstance(y, tf.Tensor): + if isinstance(x, tf.Tensor): + x = {arg_names[0]: x} + label_kwarg = next(iter(label_kwargs)) + if label_kwarg not in x: + x[label_kwarg] = y + # Otherwise, copy keys from y to x as long as they weren't already present in x + elif isinstance(y, dict): + if isinstance(x, tf.Tensor): + x = {arg_names[0]: x} + for key, val in y.items(): + if key in arg_names and key not in x: + x[key] = val + elif output_to_label.get(key, None) in arg_names and key not in x: + x[output_to_label[key]] = val + if y is None: + y = {key: val for key, val in x.items() if key in label_kwargs} + if not y and not self._using_dummy_loss: + raise ValueError("Could not find label column(s) in input dict and no separate labels were provided!") + + if isinstance(y, dict): + # Rename labels at this point to match output heads + y = {label_to_output.get(key, key): val for key, val in y.items()} + + # Run forward pass. + with tf.GradientTape() as tape: + if self._using_dummy_loss and "return_loss" in arg_names: + y_pred = self(x, training=True, return_loss=True) + else: + y_pred = self(x, training=True) + if self._using_dummy_loss: + loss = self.compiled_loss(y_pred.loss, y_pred.loss, sample_weight, regularization_losses=self.losses) + else: + loss = None + + # This next block matches outputs to label keys. Tensorflow's standard method for doing this + # can get very confused if any of the keys contain nested values (e.g. lists/tuples of Tensors) + if isinstance(y, dict) and len(y) == 1: + if list(y.keys())[0] in y_pred.keys(): + y_pred = y_pred[list(y.keys())[0]] + elif list(y_pred.keys())[0] == "loss": + y_pred = y_pred[1] + else: + y_pred = y_pred[0] + _, y = y.popitem() + elif isinstance(y, dict): + # If the labels are a dict, match keys from the output by name + y_pred = {key: val for key, val in y_pred.items() if key in y} + elif isinstance(y, tuple) or isinstance(y, list): + # If the labels are a tuple/list, match keys to the output by order, skipping the loss. + if list(y_pred.keys())[0] == "loss": + y_pred = y_pred.to_tuple()[1:] + else: + y_pred = y_pred.to_tuple() + y_pred = y_pred[: len(y)] # Remove unused fields in case those cause problems + else: + # If the labels are a single tensor, match them to the first non-loss tensor in the output + if list(y_pred.keys())[0] == "loss": + y_pred = y_pred[1] + else: + y_pred = y_pred[0] + + if loss is None: + loss = self.compiled_loss(y, y_pred, sample_weight, regularization_losses=self.losses) + + # Run backwards pass. + self.optimizer.minimize(loss, self.trainable_variables, tape=tape) + + self.compiled_metrics.update_state(y, y_pred, sample_weight) + # Collect metrics to return + return_metrics = {} + for metric in self.metrics: + result = metric.result() + if isinstance(result, dict): + return_metrics.update(result) + else: + return_metrics[metric.name] = result + return return_metrics + + def test_step(self, data): + """ + A modification of Keras's default `train_step` that correctly handles matching outputs to labels for our models + and supports directly training on the loss output head. In addition, it ensures input keys are copied to the + labels where appropriate. It will also copy label keys into the input dict when using the dummy loss, to ensure + that they are available to the model during the forward pass. + """ + # We hardcode the most common renamings; models with weirder names can set `self._label_to_output_map` + arg_names = list(inspect.signature(self.call).parameters) + label_kwargs = find_labels(self.__class__) + label_to_output = self.get_label_to_output_name_mapping() + output_to_label = {val: key for key, val in label_to_output.items()} + if not self._using_dummy_loss and parse(tf.__version__) < parse("2.11.0"): + # Newer versions leave this out + data = expand_1d(data) + x, y, sample_weight = keras.utils.unpack_x_y_sample_weight(data) + # If the inputs are mutable dictionaries, make a shallow copy of them because we will modify + # them during input/label pre-processing. This avoids surprising the user by wrecking their data. + # In addition, modifying mutable Python inputs makes XLA compilation impossible. + if isinstance(x, dict): + x = x.copy() + if isinstance(y, dict): + y = y.copy() + + # When using a dummy loss, we ensure that separate labels are copied to the correct model arguments, + # if those keys are not already present in the input dict + if self._using_dummy_loss and y is not None: + arg_names = list(inspect.signature(self.call).parameters) + # If y is a tensor and the model only has one label-like input, map y to that input + if len(label_kwargs) == 1 and isinstance(y, tf.Tensor): + if isinstance(x, tf.Tensor): + x = {arg_names[0]: x} + label_kwarg = next(iter(label_kwargs)) + if label_kwarg not in x: + x[label_kwarg] = y + # Otherwise, copy keys from y to x as long as they weren't already present in x + elif isinstance(y, dict): + if isinstance(x, tf.Tensor): + x = {arg_names[0]: x} + for key, val in y.items(): + if key in arg_names and key not in x: + x[key] = val + elif output_to_label.get(key, None) in arg_names and key not in x: + x[output_to_label[key]] = val + if y is None: + y = {key: val for key, val in x.items() if key in label_kwargs} + if not y and not self._using_dummy_loss: + raise ValueError("Could not find label column(s) in input dict and no separate labels were provided!") + + if isinstance(y, dict): + # Rename labels at this point to match output heads + y = {label_to_output.get(key, key): val for key, val in y.items()} + + # Run forward pass. + if self._using_dummy_loss and "return_loss" in arg_names: + y_pred = self(x, return_loss=True, training=False) + else: + y_pred = self(x, training=False) + if self._using_dummy_loss: + loss = self.compiled_loss(y_pred.loss, y_pred.loss, sample_weight, regularization_losses=self.losses) + else: + loss = None + + # This next block matches outputs to label keys. Tensorflow's standard method for doing this + # can get very confused if any of the keys contain nested values (e.g. lists/tuples of Tensors) + if isinstance(y, dict) and len(y) == 1: + if list(y.keys())[0] in y_pred.keys(): + y_pred = y_pred[list(y.keys())[0]] + elif list(y_pred.keys())[0] == "loss": + y_pred = y_pred[1] + else: + y_pred = y_pred[0] + _, y = y.popitem() + elif isinstance(y, dict): + # If the labels are a dict, match keys from the output by name + y_pred = {key: val for key, val in y_pred.items() if key in y} + elif isinstance(y, tuple) or isinstance(y, list): + # If the labels are a tuple/list, match keys to the output by order, skipping the loss. + if list(y_pred.keys())[0] == "loss": + y_pred = y_pred.to_tuple()[1:] + else: + y_pred = y_pred.to_tuple() + y_pred = y_pred[: len(y)] # Remove unused fields in case those cause problems + else: + # If the labels are a single tensor, match them to the first non-loss tensor in the output + if list(y_pred.keys())[0] == "loss": + y_pred = y_pred[1] + else: + y_pred = y_pred[0] + + if loss is None: + loss = self.compiled_loss(y, y_pred, sample_weight, regularization_losses=self.losses) + + self.compiled_metrics.update_state(y, y_pred, sample_weight) + # Collect metrics to return + return_metrics = {} + for metric in self.metrics: + result = metric.result() + if isinstance(result, dict): + return_metrics.update(result) + else: + return_metrics[metric.name] = result + return return_metrics + + def create_model_card( + self, + output_dir, + model_name: str, + language: Optional[str] = None, + license: Optional[str] = None, + tags: Optional[str] = None, + finetuned_from: Optional[str] = None, + tasks: Optional[str] = None, + dataset_tags: Optional[Union[str, List[str]]] = None, + dataset: Optional[Union[str, List[str]]] = None, + dataset_args: Optional[Union[str, List[str]]] = None, + ): + """ + Creates a draft of a model card using the information available to the `Trainer`. + + Args: + output_dir (`str` or `os.PathLike`): + The folder in which to create the model card. + model_name (`str`, *optional*): + The name of the model. + language (`str`, *optional*): + The language of the model (if applicable) + license (`str`, *optional*): + The license of the model. Will default to the license of the pretrained model used, if the original + model given to the `Trainer` comes from a repo on the Hub. + tags (`str` or `List[str]`, *optional*): + Some tags to be included in the metadata of the model card. + finetuned_from (`str`, *optional*): + The name of the model used to fine-tune this one (if applicable). Will default to the name of the repo + of the original model given to the `Trainer` (if it comes from the Hub). + tasks (`str` or `List[str]`, *optional*): + One or several task identifiers, to be included in the metadata of the model card. + dataset_tags (`str` or `List[str]`, *optional*): + One or several dataset tags, to be included in the metadata of the model card. + dataset (`str` or `List[str]`, *optional*): + One or several dataset identifiers, to be included in the metadata of the model card. + dataset_args (`str` or `List[str]`, *optional*): + One or several dataset arguments, to be included in the metadata of the model card. + """ + # Avoids a circular import by doing this when necessary. + from .modelcard import TrainingSummary # tests_ignore + + training_summary = TrainingSummary.from_keras( + self, + keras_history=self.history, + language=language, + license=license, + tags=tags, + model_name=model_name, + finetuned_from=finetuned_from, + tasks=tasks, + dataset_tags=dataset_tags, + dataset=dataset, + dataset_args=dataset_args, + ) + model_card = training_summary.to_model_card() + with open(os.path.join(output_dir, "README.md"), "w") as f: + f.write(model_card) + + def set_input_embeddings(self, value): + """ + Set model's input embeddings + + Args: + value (`tf.Variable`): + The new weights mapping hidden states to vocabulary. + """ + main_layer = getattr(self, self.base_model_prefix) + + if main_layer is None: + raise NotImplementedError("The model does not implements the base_model_prefix attribute.") + + try: + main_layer.set_input_embeddings(value) + except AttributeError: + logger.info("Building the model") + self.build_in_name_scope() + main_layer.set_input_embeddings(value) + + def get_output_embeddings(self) -> Union[None, keras.layers.Layer]: + """ + Returns the model's output embeddings + + Returns: + `tf.Variable`: The new weights mapping vocabulary to hidden states. + """ + if self.get_lm_head() is not None: + lm_head = self.get_lm_head() + + try: + return lm_head.get_output_embeddings() + except AttributeError: + logger.info("Building the model") + self.build_in_name_scope() + + return lm_head().get_output_embeddings() + + return None # Overwrite for models with output embeddings + + def set_output_embeddings(self, value): + """ + Set model's output embeddings + + Args: + value (`tf.Variable`): + The new weights mapping hidden states to vocabulary. + """ + if self.get_lm_head() is not None: + lm_head = self.get_lm_head() + try: + lm_head.set_output_embeddings(value) + except AttributeError: + logger.info("Building the model") + self.build_in_name_scope() + lm_head.set_output_embeddings(value) + + def get_output_layer_with_bias(self) -> Union[None, keras.layers.Layer]: + """ + Get the layer that handles a bias attribute in case the model has an LM head with weights tied to the + embeddings + + Return: + `keras.layers.Layer`: The layer that handles the bias, None if not an LM model. + """ + warnings.warn( + "The method get_output_layer_with_bias is deprecated. Please use `get_lm_head` instead.", FutureWarning + ) + return self.get_lm_head() + + def get_prefix_bias_name(self) -> Union[None, str]: + """ + Get the concatenated _prefix name of the bias from the model name to the parent layer + + Return: + `str`: The _prefix name of the bias. + """ + warnings.warn("The method get_prefix_bias_name is deprecated. Please use `get_bias` instead.", FutureWarning) + return None + + def get_bias(self) -> Union[None, Dict[str, tf.Variable]]: + """ + Dict of bias attached to an LM head. The key represents the name of the bias attribute. + + Return: + `tf.Variable`: The weights representing the bias, None if not an LM model. + """ + if self.get_lm_head() is not None: + lm_head = self.get_lm_head() + try: + return lm_head.get_bias() + except AttributeError: + self.build_in_name_scope() + + return lm_head.get_bias() + return None + + def set_bias(self, value): + """ + Set all the bias in the LM head. + + Args: + value (`Dict[tf.Variable]`): + All the new bias attached to an LM head. + """ + if self.get_lm_head() is not None: + lm_head = self.get_lm_head() + try: + lm_head.set_bias(value) + except AttributeError: + self.build_in_name_scope() + lm_head.set_bias(value) + + def get_lm_head(self) -> keras.layers.Layer: + """ + The LM Head layer. This method must be overwritten by all the models that have a lm head. + + Return: + `keras.layers.Layer`: The LM head layer if the model has one, None if not. + """ + return None + + def resize_token_embeddings( + self, new_num_tokens: Optional[int] = None + ) -> Union[keras.layers.Embedding, tf.Variable]: + """ + Resizes input token embeddings matrix of the model if `new_num_tokens != config.vocab_size`. + + Takes care of tying weights embeddings afterwards if the model class has a `tie_weights()` method. + + Arguments: + new_num_tokens (`int`, *optional*): + The number of new tokens in the embedding matrix. Increasing the size will add newly initialized + vectors at the end. Reducing the size will remove vectors from the end. If not provided or `None`, just + returns a pointer to the input tokens without doing anything. + + Return: + `tf.Variable` or `keras.layers.Embedding`: Pointer to the input tokens of the model. + """ + # TODO (joao): flagged for replacement (by `_v2_resized_token_embeddings`) due to embeddings refactor + + # Run the new code path if the model has a keras embeddings layer + if isinstance(self.get_input_embeddings(), keras.layers.Embedding): + return self._v2_resized_token_embeddings(new_num_tokens) + + if new_num_tokens is None or new_num_tokens == self.config.vocab_size: + return self._get_word_embedding_weight(self.get_input_embeddings()) + + model_embeds = self._resize_token_embeddings(new_num_tokens) + + # Update base model and current model config + self.config.vocab_size = new_num_tokens + + return model_embeds + + def _v2_resized_token_embeddings(self, new_num_tokens: Optional[int] = None) -> keras.layers.Embedding: + """ + Resizes input token embeddings matrix of the model if `new_num_tokens != config.vocab_size`. + + Arguments: + new_num_tokens (`int`, *optional*): + The number of new tokens in the embedding matrix. Increasing the size will add newly initialized + vectors at the end. Reducing the size will remove vectors from the end. If not provided or `None`, just + returns a pointer to the input tokens without doing anything. + + Return: + `keras.layers.Embedding`: Pointer to the input tokens of the model. + """ + if new_num_tokens is None or new_num_tokens == self.config.vocab_size: + return self.get_input_embeddings() + + model_embeds = self._v2_resize_token_embeddings(new_num_tokens) + + # Update base model and current model config + self.config.vocab_size = new_num_tokens + + return model_embeds + + def _get_word_embedding_weight(model, embedding_layer): + # TODO (joao): flagged for delection due to embeddings refactor + + # If the variable holds the weights themselves, return them + if isinstance(embedding_layer, tf.Tensor): + return embedding_layer + # Otherwise, try to get them from the layer's attributes + + embeds = getattr(embedding_layer, "weight", None) + if embeds is not None: + return embeds + + embeds = getattr(embedding_layer, "decoder", None) + if embeds is not None: + return embeds + + # The reason why the attributes don't exist might be + # because the model is not built, so retry getting + # the argument after building the model + model.build_in_name_scope() + + embeds = getattr(embedding_layer, "weight", None) + if embeds is not None: + return embeds + + embeds = getattr(embedding_layer, "decoder", None) + if embeds is not None: + return embeds + + return None + + def _resize_token_embeddings(self, new_num_tokens): + # TODO (joao): flagged for replacement (by `_v2_resize_token_embeddings`) due to embeddings refactor + old_embeddings = self._get_word_embedding_weight(self.get_input_embeddings()) + new_embeddings = self._get_resized_embeddings(old_embeddings, new_num_tokens) + + # if word embeddings are not tied, make sure that lm head bias is resized as well + if self.get_bias() is not None: + old_lm_head_bias = self.get_bias() + new_lm_head_bias = self._get_resized_lm_head_bias(old_lm_head_bias, new_num_tokens) + + self.set_bias(new_lm_head_bias) + + # if word embeddings are not tied, make sure that lm head decoder is resized as well + if self.get_output_embeddings() is not None: + old_lm_head_decoder = self._get_word_embedding_weight(self.get_output_embeddings()) + new_lm_head_decoder = self._get_resized_lm_head_decoder(old_lm_head_decoder, new_num_tokens) + + self.set_output_embeddings(new_lm_head_decoder) + + self.set_input_embeddings(new_embeddings) + + return self.get_input_embeddings() + + def _v2_resize_token_embeddings(self, new_num_tokens): + old_embeddings = self.get_input_embeddings() + new_embeddings = self._v2_get_resized_embeddings(old_embeddings, new_num_tokens) + self.set_input_embeddings(new_embeddings) + + # If word embeddings are not tied, make sure that lm head bias is resized as well + if self.get_bias() is not None: + old_lm_head_bias = self.get_bias() + new_lm_head_bias = self._v2_get_resized_lm_head_bias(old_lm_head_bias, new_num_tokens) + self.set_bias(new_lm_head_bias) + + # If word embeddings are not tied, make sure that lm head decoder is resized as well. + tied_weights = self.get_input_embeddings() == self.get_output_embeddings() + if self.get_output_embeddings() is not None and not tied_weights: + old_lm_head_decoder = self._get_word_embedding_weight(self.get_output_embeddings()) + # TODO (joao): this one probably needs a v2 version with other models + new_lm_head_decoder = self._get_resized_lm_head_decoder(old_lm_head_decoder, new_num_tokens) + self.set_output_embeddings(new_lm_head_decoder) + + return self.get_input_embeddings() + + def _get_resized_lm_head_bias(self, old_lm_head_bias, new_num_tokens): + """ + Build a resized bias from the old ones. Increasing the size will add newly initialized vectors at the end. + Reducing the size will remove vectors from the end + + Args: + old_lm_head_bias (`tf.Variable`): + Old lm head bias to be resized. + new_num_tokens (`int`, *optional*): + New number of tokens in the linear matrix. + + Increasing the size will add newly initialized vectors at the end. Reducing the size will remove + vectors from the end. If not provided or `None`, just returns None + + Return: + `tf.Variable`: Pointer to the resized bias. + """ + # TODO (joao): flagged for replacement (by `_v2_get_resized_lm_head_bias`) due to embeddings refactor + new_lm_head_bias = {} + + for attr, weight in old_lm_head_bias.items(): + first_dim, old_num_tokens = (None, shape_list(weight)[0]) if tf.rank(weight) == 1 else shape_list(weight) + size_diff = new_num_tokens - old_num_tokens + final_shape = [new_num_tokens] if first_dim is None else [first_dim, new_num_tokens] + + # initialize new bias + if tf.math.greater(size_diff, 0): + padding_shape = [[0, size_diff]] if first_dim is None else [[0, 0], [0, size_diff]] + current_bias = tf.pad(weight.value(), tf.convert_to_tensor(padding_shape), constant_values=-1) + num_tokens_to_copy = min(old_num_tokens, new_num_tokens) + mask_shape = [num_tokens_to_copy] if first_dim is None else [1, num_tokens_to_copy] + bias_mask = tf.fill(tf.convert_to_tensor(mask_shape), True) + bias_mask = tf.pad(bias_mask, tf.convert_to_tensor(padding_shape), constant_values=False) + else: + slice_from = [0] if first_dim is None else [0, 0] + current_bias = tf.slice( + weight.value(), tf.convert_to_tensor(slice_from), tf.convert_to_tensor(final_shape) + ) + bias_mask = tf.fill(tf.convert_to_tensor(final_shape), True) + + new_bias = self.add_weight( + shape=final_shape, + initializer="zeros", + trainable=True, + name=weight.name.split(":")[0], + ) + init_bias = tf.where(bias_mask, current_bias, new_bias.value()) + + new_bias.assign(init_bias) + new_lm_head_bias[attr] = new_bias + + return new_lm_head_bias + + def _v2_get_resized_lm_head_bias( + self, old_lm_head_bias: Dict[str, tf.Variable], new_num_tokens: int + ) -> Dict[str, tf.Tensor]: + """ + Build a resized bias from the old ones. Increasing the size will add newly initialized vectors at the end. + Reducing the size will remove vectors from the end + + Args: + old_lm_head_bias (`Dict[str, tf.Variable]`): + Old lm head bias to be resized. + new_num_tokens (`int`): + New number of tokens in the linear matrix. Increasing the size will add newly initialized vectors at + the end. Reducing the size will remove vectors from the end. + + Return: + `tf.Tensor`: Values for the resized bias. + """ + new_lm_head_bias = {} + + for attr, weight in old_lm_head_bias.items(): + # Determine the size difference (depending on the shape) + first_dim, old_num_tokens = (None, shape_list(weight)[0]) if tf.rank(weight) == 1 else shape_list(weight) + size_diff = new_num_tokens - old_num_tokens + + # Copy the old bias values to the new bias + if old_num_tokens > new_num_tokens: + new_bias = weight.value()[..., :new_num_tokens] + else: + padding_shape = [[0, size_diff]] if first_dim is None else [[0, 0], [0, size_diff]] + new_bias = tf.pad(weight.value(), tf.convert_to_tensor(padding_shape)) + + new_lm_head_bias[attr] = new_bias + return new_lm_head_bias + + def _get_resized_lm_head_decoder(self, old_lm_head_decoder, new_num_tokens): + """ + Build a resized decoder from the old ones. Increasing the size will add newly initialized vectors at the end. + Reducing the size will remove vectors from the end + + Args: + old_lm_head_decoder (`tf.Variable`): + Old lm head decoder to be resized. + new_num_tokens (`int`, *optional*): + New number of tokens in the linear matrix. + + Increasing the size will add newly initialized vectors at the end. Reducing the size will remove + vectors from the end. If not provided or `None`, just returns None + + Return: + `tf.Variable`: Pointer to the resized decoder or None if the output embeddings are different from the input + ones. + """ + new_lm_head_decoder = old_lm_head_decoder + is_input_output_equals = tf.reduce_any( + self._get_word_embedding_weight(self.get_input_embeddings()) == old_lm_head_decoder + ) + + if old_lm_head_decoder is not None and not is_input_output_equals: + old_embedding_dim = shape_list(old_lm_head_decoder)[1] + decoder_mask, current_decoder = init_copy_embeddings(old_lm_head_decoder, new_num_tokens) + new_lm_head_decoder = self.add_weight( + shape=(new_num_tokens, old_embedding_dim), + initializer="zeros", + trainable=True, + name=old_lm_head_decoder.name.split(":")[0], + ) + init_decoder = tf.where(decoder_mask, current_decoder, new_lm_head_decoder.value()) + + new_lm_head_decoder.assign(init_decoder) + + return new_lm_head_decoder + + def _get_resized_embeddings(self, old_embeddings, new_num_tokens=None) -> tf.Variable: + """ + Build a resized Embedding weights from a provided token Embedding weights. Increasing the size will add newly + initialized vectors at the end. Reducing the size will remove vectors from the end + + Args: + old_embeddings (`tf.Variable`): + Old embeddings to be resized. + new_num_tokens (`int`, *optional*): + New number of tokens in the embedding matrix. + + Increasing the size will add newly initialized vectors at the end. Reducing the size will remove + vectors from the end. If not provided or `None`, just returns a pointer to the input tokens + `tf.Variable` module of the model without doing anything. + + Return: + `tf.Variable`: Pointer to the resized Embedding Module or the old Embedding Module if `new_num_tokens` is + `None` + """ + # TODO (joao): flagged for replacement (by `_v2_get_resized_embeddings`) due to embeddings refactor + old_embedding_dim = shape_list(old_embeddings)[1] + init_range = getattr(self.config, "initializer_range", 0.02) + embeddings_mask, current_embeddings = init_copy_embeddings(old_embeddings, new_num_tokens) + new_embeddings = self.add_weight( + name=old_embeddings.name.split(":")[0], + shape=[new_num_tokens, old_embedding_dim], + initializer=get_initializer(init_range), + dtype=tf.float32, + ) + init_embeddings = tf.where(embeddings_mask, current_embeddings, new_embeddings.value()) + + new_embeddings.assign(init_embeddings) + + return new_embeddings + + def _v2_get_resized_embeddings( + self, old_embeddings: keras.layers.Embedding, new_num_tokens: int + ) -> keras.layers.Embedding: + """ + Build a resized Embedding layer from a provided Embedding layer. Increasing the size will add newly initialized + vectors at the end. Reducing the size will remove vectors from the end. + + Args: + old_embeddings (`keras.layers.Embedding`): + Old embeddings to be resized. + new_num_tokens (`int`, *optional*): + New number of tokens in the embedding matrix. + + Return: + `keras.layers.Embedding`: Resized Embedding layer. + """ + + # Get the initialization range for the embeddings + init_range = 0.02 # default value + potential_initialization_variable_names = [ + "initializer_range", # most common + "initializer_factor", # e.g. T5 + "init_std", # e.g BART + ] + for var_name in potential_initialization_variable_names: + if hasattr(self.config, var_name): + init_range = getattr(self.config, var_name) + + # Get a new (initialized) embeddings layer + new_embeddings = keras.layers.Embedding( + input_dim=new_num_tokens, + output_dim=old_embeddings.output_dim, + embeddings_initializer=keras.initializers.TruncatedNormal(stddev=init_range), + name=old_embeddings.embeddings.name[:-13], # exact same scoped name except "/embeddings:0" + ) + new_embeddings(tf.constant([[0]])) + + # Copy the old embeddings to the new embeddings + if old_embeddings.input_dim >= new_num_tokens: + init_embeddings = old_embeddings.embeddings[:new_num_tokens] + else: + init_embeddings = tf.concat( + [old_embeddings.embeddings, new_embeddings.embeddings[old_embeddings.input_dim :]], axis=0 + ) + new_embeddings.embeddings.assign(init_embeddings) + return new_embeddings + + def prune_heads(self, heads_to_prune): + """ + Prunes heads of the base model. + + Arguments: + heads_to_prune (`Dict[int, List[int]]`): + Dictionary with keys being selected layer indices (`int`) and associated values being the list of heads + to prune in said layer (list of `int`). For instance {1: [0, 2], 2: [2, 3]} will prune heads 0 and 2 on + layer 1 and heads 2 and 3 on layer 2. + """ + raise NotImplementedError + + def save_pretrained( + self, + save_directory, + saved_model=False, + version=1, + push_to_hub=False, + signatures=None, + max_shard_size: Union[int, str] = "5GB", + create_pr: bool = False, + safe_serialization: bool = False, + token: Optional[Union[str, bool]] = None, + **kwargs, + ): + """ + Save a model and its configuration file to a directory, so that it can be re-loaded using the + [`~TFPreTrainedModel.from_pretrained`] class method. + + Arguments: + save_directory (`str`): + Directory to which to save. Will be created if it doesn't exist. + saved_model (`bool`, *optional*, defaults to `False`): + If the model has to be saved in saved model format as well or not. + version (`int`, *optional*, defaults to 1): + The version of the saved model. A saved model needs to be versioned in order to be properly loaded by + TensorFlow Serving as detailed in the official documentation + https://www.tensorflow.org/tfx/serving/serving_basic + push_to_hub (`bool`, *optional*, defaults to `False`): + Whether or not to push your model to the Hugging Face model hub after saving it. You can specify the + repository you want to push to with `repo_id` (will default to the name of `save_directory` in your + namespace). + signatures (`dict` or `tf.function`, *optional*): + Model's signature used for serving. This will be passed to the `signatures` argument of model.save(). + max_shard_size (`int` or `str`, *optional*, defaults to `"10GB"`): + The maximum size for a checkpoint before being sharded. Checkpoints shard will then be each of size + lower than this size. If expressed as a string, needs to be digits followed by a unit (like `"5MB"`). + + + + If a single weight of the model is bigger than `max_shard_size`, it will be in its own checkpoint shard + which will be bigger than `max_shard_size`. + + + + create_pr (`bool`, *optional*, defaults to `False`): + Whether or not to create a PR with the uploaded files or directly commit. + safe_serialization (`bool`, *optional*, defaults to `False`): + Whether to save the model using `safetensors` or the traditional TensorFlow way (that uses `h5`). + token (`str` or `bool`, *optional*): + The token to use as HTTP bearer authorization for remote files. If `True`, or not specified, will use + the token generated when running `huggingface-cli login` (stored in `~/.huggingface`). + kwargs (`Dict[str, Any]`, *optional*): + Additional key word arguments passed along to the [`~utils.PushToHubMixin.push_to_hub`] method. + """ + use_auth_token = kwargs.pop("use_auth_token", None) + + if use_auth_token is not None: + warnings.warn( + "The `use_auth_token` argument is deprecated and will be removed in v5 of Transformers. Please use `token` instead.", + FutureWarning, + ) + if token is not None: + raise ValueError( + "`token` and `use_auth_token` are both specified. Please set only the argument `token`." + ) + token = use_auth_token + + if token is not None: + kwargs["token"] = token + + if os.path.isfile(save_directory): + logger.error(f"Provided path ({save_directory}) should be a directory, not a file") + return + + os.makedirs(save_directory, exist_ok=True) + + if push_to_hub: + commit_message = kwargs.pop("commit_message", None) + repo_id = kwargs.pop("repo_id", save_directory.split(os.path.sep)[-1]) + repo_id = self._create_repo(repo_id, **kwargs) + files_timestamps = self._get_files_timestamps(save_directory) + + if saved_model: + # If `torch_dtype` is in the config with a torch dtype class as the value, we need to change it to string. + # (Although TF doesn't care about this attribute, we can't just remove it or set it to `None`.) + if getattr(self.config, "torch_dtype", None) is not None and not isinstance(self.config.torch_dtype, str): + self.config.torch_dtype = str(self.config.torch_dtype).split(".")[1] + if signatures is None: + serving_default = self.serving.get_concrete_function(self.input_signature) + if any(spec.dtype == tf.int32 for spec in self.input_signature.values()): + int64_spec = { + key: tf.TensorSpec( + shape=spec.shape, dtype=tf.int64 if spec.dtype == tf.int32 else spec.dtype, name=spec.name + ) + for key, spec in self.input_signature.items() + } + int64_serving = self.serving.get_concrete_function(int64_spec) + signatures = {"serving_default": serving_default, "int64_serving": int64_serving} + else: + signatures = serving_default + saved_model_dir = os.path.join(save_directory, "saved_model", str(version)) + self.save(saved_model_dir, include_optimizer=False, signatures=signatures) + logger.info(f"Saved model created in {saved_model_dir}") + + # Save configuration file + self.config.architectures = [self.__class__.__name__[2:]] + + # If we have a custom model, we copy the file defining it in the folder and set the attributes so it can be + # loaded from the Hub. + if self._auto_class is not None: + custom_object_save(self, save_directory, config=self.config) + + self.config.save_pretrained(save_directory) + if self.can_generate(): + self.generation_config.save_pretrained(save_directory) + + # If we save using the predefined names, we can load using `from_pretrained` + weights_name = SAFE_WEIGHTS_NAME if safe_serialization else TF2_WEIGHTS_NAME + output_model_file = os.path.join(save_directory, weights_name) + + shards, index = tf_shard_checkpoint(self.weights, max_shard_size, weights_name=weights_name) + + # Clean the folder from a previous save + for filename in os.listdir(save_directory): + full_filename = os.path.join(save_directory, filename) + # If we have a shard file that is not going to be replaced, we delete it, but only from the main process + # in distributed settings to avoid race conditions. + weights_no_suffix = weights_name.replace(".bin", "").replace(".safetensors", "") + if ( + filename.startswith(weights_no_suffix) + and os.path.isfile(full_filename) + and filename not in shards.keys() + ): + os.remove(full_filename) + + if index is None: + if safe_serialization: + state_dict = {strip_model_name_and_prefix(w.name): w.value() for w in self.weights} + safe_save_file(state_dict, output_model_file, metadata={"format": "tf"}) + else: + self.save_weights(output_model_file) + logger.info(f"Model weights saved in {output_model_file}") + else: + save_index_file = SAFE_WEIGHTS_INDEX_NAME if safe_serialization else TF2_WEIGHTS_INDEX_NAME + save_index_file = os.path.join(save_directory, save_index_file) + # Save the index as well + with open(save_index_file, "w", encoding="utf-8") as index_file: + content = json.dumps(index, indent=2, sort_keys=True) + "\n" + index_file.write(content) + logger.info( + f"The model is bigger than the maximum size per checkpoint ({max_shard_size}) and is going to be " + f"split in {len(shards)} checkpoint shards. You can find where each parameters has been saved in the " + f"index located at {save_index_file}." + ) + for shard_file, shard in shards.items(): + if safe_serialization: + shard_state_dict = {strip_model_name_and_prefix(w.name): w.value() for w in shard} + safe_save_file( + shard_state_dict, os.path.join(save_directory, shard_file), metadata={"format": "tf"} + ) + else: + with h5py.File(os.path.join(save_directory, shard_file), mode="w") as shard_file: + layers = [] + for layer in sorted(shard, key=lambda x: x.name): + if "model." in layer.name or len(layer.name.split("/")) == 1: + layer_name = layer.name + else: + layer_name = "/".join(layer.name.split("/")[1:]) + param_dset = shard_file.create_dataset( + layer_name, layer.numpy().shape, dtype=layer.numpy().dtype + ) + param_dset[:] = layer.numpy() + layers.append(layer_name.encode("utf8")) + save_attributes_to_hdf5_group(shard_file, "layer_names", layers) + + if push_to_hub: + self._upload_modified_files( + save_directory, + repo_id, + files_timestamps, + commit_message=commit_message, + token=token, + ) + + @classmethod + def from_pretrained( + cls, + pretrained_model_name_or_path: Optional[Union[str, os.PathLike]], + *model_args, + config: Optional[Union[PretrainedConfig, str, os.PathLike]] = None, + cache_dir: Optional[Union[str, os.PathLike]] = None, + ignore_mismatched_sizes: bool = False, + force_download: bool = False, + local_files_only: bool = False, + token: Optional[Union[str, bool]] = None, + revision: str = "main", + use_safetensors: bool = None, + **kwargs, + ): + r""" + Instantiate a pretrained TF 2.0 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 (`str`, *optional*): + Can be either: + + - A string, the *model id* of a pretrained model hosted inside a model repo on huggingface.co. + - A path to a *directory* containing model weights saved using + [`~TFPreTrainedModel.save_pretrained`], e.g., `./my_model_directory/`. + - A path or url to a *PyTorch state_dict save file* (e.g, `./pt_model/pytorch_model.bin`). In this + case, `from_pt` should be set to `True` and a configuration object should be provided as `config` + argument. This loading path is slower than converting the PyTorch model in a TensorFlow model + using the provided conversion scripts and loading the TensorFlow model afterwards. + - `None` if you are both providing the configuration and state dictionary (resp. with keyword + arguments `config` and `state_dict`). + model_args (sequence of positional arguments, *optional*): + All remaining positional arguments will be passed to the underlying model's `__init__` method. + config (`Union[PretrainedConfig, str]`, *optional*): + Can be either: + + - an instance of a class derived from [`PretrainedConfig`], + - a string valid as input to [`~PretrainedConfig.from_pretrained`]. + + Configuration for the model to use instead of an automatically loaded configuration. 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 [`~TFPreTrainedModel.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. + from_pt (`bool`, *optional*, defaults to `False`): + Load the model weights from a PyTorch state_dict save file (see docstring of + `pretrained_model_name_or_path` argument). + ignore_mismatched_sizes (`bool`, *optional*, defaults to `False`): + Whether or not to raise an error if some of the weights from the checkpoint do not have the same size + as the weights of the model (if for instance, you are instantiating a model with 10 labels from a + checkpoint with 3 labels). + cache_dir (`str`, *optional*): + Path to a directory in which a downloaded pretrained model configuration should be cached if the + standard cache should not be used. + force_download (`bool`, *optional*, defaults to `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 (`bool`, *optional*, defaults to `False`): + Whether or not to delete incompletely received files. Will attempt to resume the download if such a + file exists. + proxies: + (`Dict[str, str], `optional`): A dictionary of proxy servers to use by protocol or endpoint, e.g., + `{'http': 'foo.bar:3128', 'http://hostname': 'foo.bar:4012'}`. The proxies are used on each request. + output_loading_info(`bool`, *optional*, defaults to `False`): Whether ot not to also return a + dictionary containing missing keys, unexpected keys and error messages. + local_files_only(`bool`, *optional*, defaults to `False`): + Whether or not to only look at local files (e.g., not try downloading the model). + token (`str` or `bool`, *optional*): + The token to use as HTTP bearer authorization for remote files. If `True`, or not specified, will use + the token generated when running `huggingface-cli login` (stored in `~/.huggingface`). + revision (`str`, *optional*, defaults to `"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. + + + + + To test a pull request you made on the Hub, you can pass `revision="refs/pr/". + + + + mirror (`str`, *optional*): + Mirror source to accelerate downloads in China. If you are from China and have an accessibility + problem, you can set this option to resolve it. Note that we do not guarantee the timeliness or safety. + Please refer to the mirror site for more information. + subfolder (`str`, *optional*, defaults to `""`): + In case the relevant files are located inside a subfolder of the model repo on huggingface.co, you can + specify the folder name here. + tf_to_pt_weight_rename (`Callable`, *optional*): + A function that is called to transform the names of weights during the PyTorch to TensorFlow + crossloading process. This is not necessary for most models, but is useful to allow composite models to + be crossloaded correctly. + use_safetensors (`bool`, *optional*, defaults to `None`): + Whether or not to use `safetensors` checkpoints. Defaults to `None`. If not specified and `safetensors` + is not installed, it will be set to `False`. + 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., + `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 ([`~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: + + ```python + >>> from transformers import BertConfig, TFBertModel + + >>> # Download model and configuration from huggingface.co and cache. + >>> model = TFBertModel.from_pretrained("google-bert/bert-base-uncased") + >>> # Model was saved using *save_pretrained('./test/saved_model/')* (for example purposes, not runnable). + >>> model = TFBertModel.from_pretrained("./test/saved_model/") + >>> # Update configuration during loading. + >>> model = TFBertModel.from_pretrained("google-bert/bert-base-uncased", output_attentions=True) + >>> assert model.config.output_attentions == True + >>> # Loading from a Pytorch model file instead of a TensorFlow checkpoint (slower, for example purposes, not runnable). + >>> config = BertConfig.from_json_file("./pt_model/my_pt_model_config.json") + >>> model = TFBertModel.from_pretrained("./pt_model/my_pytorch_model.bin", from_pt=True, config=config) + ```""" + from_pt = kwargs.pop("from_pt", False) + resume_download = kwargs.pop("resume_download", False) + proxies = kwargs.pop("proxies", None) + output_loading_info = kwargs.pop("output_loading_info", False) + use_auth_token = kwargs.pop("use_auth_token", None) + trust_remote_code = kwargs.pop("trust_remote_code", None) + _ = kwargs.pop("mirror", None) + load_weight_prefix = kwargs.pop("load_weight_prefix", None) + from_pipeline = kwargs.pop("_from_pipeline", None) + from_auto_class = kwargs.pop("_from_auto", False) + subfolder = kwargs.pop("subfolder", "") + commit_hash = kwargs.pop("_commit_hash", None) + tf_to_pt_weight_rename = kwargs.pop("tf_to_pt_weight_rename", None) + + # Not relevant for TF models + _ = kwargs.pop("adapter_kwargs", None) + + if use_auth_token is not None: + warnings.warn( + "The `use_auth_token` argument is deprecated and will be removed in v5 of Transformers. Please use `token` instead.", + FutureWarning, + ) + if token is not None: + raise ValueError( + "`token` and `use_auth_token` are both specified. Please set only the argument `token`." + ) + token = use_auth_token + + if trust_remote_code is True: + logger.warning( + "The argument `trust_remote_code` is to be used with Auto classes. It has no effect here and is" + " ignored." + ) + + user_agent = {"file_type": "model", "framework": "tensorflow", "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 + + if use_safetensors is None and not is_safetensors_available(): + use_safetensors = False + + # 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, + cache_dir=cache_dir, + return_unused_kwargs=True, + force_download=force_download, + resume_download=resume_download, + proxies=proxies, + local_files_only=local_files_only, + token=token, + revision=revision, + _from_auto=from_auto_class, + _from_pipeline=from_pipeline, + _commit_hash=commit_hash, + **kwargs, + ) + else: + model_kwargs = kwargs + + if commit_hash is None: + commit_hash = getattr(config, "_commit_hash", None) + + # This variable will flag if we're loading a sharded checkpoint. In this case the archive file is just the + # index of the files. + is_sharded = False + # Load model + if pretrained_model_name_or_path is not None: + pretrained_model_name_or_path = str(pretrained_model_name_or_path) + is_local = os.path.isdir(pretrained_model_name_or_path) + if is_local: + if from_pt and os.path.isfile(os.path.join(pretrained_model_name_or_path, WEIGHTS_NAME)): + # Load from a PyTorch checkpoint in priority if from_pt + archive_file = os.path.join(pretrained_model_name_or_path, WEIGHTS_NAME) + elif from_pt and os.path.isfile(os.path.join(pretrained_model_name_or_path, WEIGHTS_INDEX_NAME)): + # Load from a sharded PyTorch checkpoint + archive_file = os.path.join(pretrained_model_name_or_path, WEIGHTS_INDEX_NAME) + is_sharded = True + elif use_safetensors is not False and os.path.isfile( + os.path.join(pretrained_model_name_or_path, SAFE_WEIGHTS_NAME) + ): + # Load from a safetensors checkpoint + archive_file = os.path.join(pretrained_model_name_or_path, SAFE_WEIGHTS_NAME) + elif use_safetensors is not False and os.path.isfile( + os.path.join(pretrained_model_name_or_path, SAFE_WEIGHTS_INDEX_NAME) + ): + # Load from a sharded safetensors checkpoint + archive_file = os.path.join(pretrained_model_name_or_path, SAFE_WEIGHTS_INDEX_NAME) + is_sharded = True + elif os.path.isfile(os.path.join(pretrained_model_name_or_path, TF2_WEIGHTS_NAME)): + # Load from a TF 2.0 checkpoint + archive_file = os.path.join(pretrained_model_name_or_path, TF2_WEIGHTS_NAME) + elif os.path.isfile(os.path.join(pretrained_model_name_or_path, TF2_WEIGHTS_INDEX_NAME)): + # Load from a sharded TF 2.0 checkpoint + archive_file = os.path.join(pretrained_model_name_or_path, TF2_WEIGHTS_INDEX_NAME) + is_sharded = True + + # At this stage we don't have a weight file so we will raise an error. + elif use_safetensors: + raise EnvironmentError( + f"Error no file named {SAFE_WEIGHTS_NAME} or {SAFE_WEIGHTS_INDEX_NAME} found in directory {pretrained_model_name_or_path}. " + f"Please make sure that the model has been saved with `safe_serialization=True` or do not " + f"set `use_safetensors=True`." + ) + elif os.path.isfile(os.path.join(pretrained_model_name_or_path, WEIGHTS_NAME)) or os.path.isfile( + os.path.join(pretrained_model_name_or_path, WEIGHTS_INDEX_NAME) + ): + raise EnvironmentError( + f"Error no file named {TF2_WEIGHTS_NAME} or {SAFE_WEIGHTS_NAME} found in directory {pretrained_model_name_or_path} " + "but there is a file for PyTorch weights. Use `from_pt=True` to load this model from those " + "weights." + ) + else: + raise EnvironmentError( + f"Error no file named {TF2_WEIGHTS_NAME}, {SAFE_WEIGHTS_NAME} or {WEIGHTS_NAME} found in directory " + f"{pretrained_model_name_or_path}." + ) + elif os.path.isfile(pretrained_model_name_or_path): + archive_file = pretrained_model_name_or_path + is_local = True + elif os.path.isfile(pretrained_model_name_or_path + ".index"): + archive_file = pretrained_model_name_or_path + ".index" + is_local = True + elif is_remote_url(pretrained_model_name_or_path): + filename = pretrained_model_name_or_path + resolved_archive_file = download_url(pretrained_model_name_or_path) + else: + # set correct filename + if from_pt: + filename = WEIGHTS_NAME + elif use_safetensors is not False: + filename = SAFE_WEIGHTS_NAME + else: + filename = TF2_WEIGHTS_NAME + + try: + # Load from URL or cache if already cached + cached_file_kwargs = { + "cache_dir": cache_dir, + "force_download": force_download, + "proxies": proxies, + "resume_download": resume_download, + "local_files_only": local_files_only, + "token": token, + "user_agent": user_agent, + "revision": revision, + "subfolder": subfolder, + "_raise_exceptions_for_gated_repo": False, + "_raise_exceptions_for_missing_entries": False, + "_commit_hash": commit_hash, + } + resolved_archive_file = cached_file(pretrained_model_name_or_path, filename, **cached_file_kwargs) + + # Since we set _raise_exceptions_for_missing_entries=False, we don't get an exception but a None + # result when internet is up, the repo and revision exist, but the file does not. + if resolved_archive_file is None and filename == SAFE_WEIGHTS_NAME: + # Did not find the safetensors file, let's fallback to TF. + # No support for sharded safetensors yet, so we'll raise an error if that's all we find. + filename = TF2_WEIGHTS_NAME + resolved_archive_file = cached_file( + pretrained_model_name_or_path, TF2_WEIGHTS_NAME, **cached_file_kwargs + ) + if resolved_archive_file is None and filename == TF2_WEIGHTS_NAME: + # Maybe the checkpoint is sharded, we try to grab the index name in this case. + resolved_archive_file = cached_file( + pretrained_model_name_or_path, TF2_WEIGHTS_INDEX_NAME, **cached_file_kwargs + ) + if resolved_archive_file is not None: + is_sharded = True + if resolved_archive_file is None and filename == WEIGHTS_NAME: + # Maybe the checkpoint is sharded, we try to grab the index name in this case. + resolved_archive_file = cached_file( + pretrained_model_name_or_path, WEIGHTS_INDEX_NAME, **cached_file_kwargs + ) + if resolved_archive_file is not None: + is_sharded = True + if resolved_archive_file is None: + # Otherwise, maybe there is a PyTorch or Flax model file. We try those to give a helpful error + # message. + has_file_kwargs = { + "revision": revision, + "proxies": proxies, + "token": token, + } + if has_file(pretrained_model_name_or_path, SAFE_WEIGHTS_INDEX_NAME, **has_file_kwargs): + is_sharded = True + elif has_file(pretrained_model_name_or_path, WEIGHTS_NAME, **has_file_kwargs): + raise EnvironmentError( + f"{pretrained_model_name_or_path} does not appear to have a file named" + f" {TF2_WEIGHTS_NAME} but there is a file for PyTorch weights. Use `from_pt=True` to" + " load this model from those weights." + ) + else: + raise EnvironmentError( + f"{pretrained_model_name_or_path} does not appear to have a file named {WEIGHTS_NAME}," + f" {TF2_WEIGHTS_NAME} or {TF_WEIGHTS_NAME}" + ) + + except EnvironmentError: + # Raise any environment error raise by `cached_file`. It will have a helpful error message adapted + # to the original exception. + raise + except Exception: + # For any other exception, we throw a generic error. + + raise EnvironmentError( + f"Can't load the model for '{pretrained_model_name_or_path}'. If you were trying to load it" + " from 'https://huggingface.co/models', make sure you don't have a local directory with the" + f" same name. Otherwise, make sure '{pretrained_model_name_or_path}' is the correct path to a" + f" directory containing a file named {WEIGHTS_NAME}, {TF2_WEIGHTS_NAME} or {TF_WEIGHTS_NAME}" + ) + if is_local: + logger.info(f"loading weights file {archive_file}") + resolved_archive_file = archive_file + filename = resolved_archive_file.split(os.path.sep)[-1] + else: + logger.info(f"loading weights file {filename} from cache at {resolved_archive_file}") + else: + resolved_archive_file = None + + # We'll need to download and cache each checkpoint shard if the checkpoint is sharded. + if is_sharded: + # resolved_archive_file becomes a list of files that point to the different checkpoint shards in this case. + resolved_archive_file, sharded_metadata = get_checkpoint_shard_files( + pretrained_model_name_or_path, + resolved_archive_file, + cache_dir=cache_dir, + force_download=force_download, + proxies=proxies, + resume_download=resume_download, + local_files_only=local_files_only, + token=token, + user_agent=user_agent, + revision=revision, + _commit_hash=commit_hash, + ) + + safetensors_from_pt = False + if filename == SAFE_WEIGHTS_NAME: + with safe_open(resolved_archive_file, framework="tf") as f: + safetensors_metadata = f.metadata() + if safetensors_metadata is None or safetensors_metadata.get("format") not in ["pt", "tf", "flax", "mlx"]: + raise OSError( + f"The safetensors archive passed at {resolved_archive_file} does not contain the valid metadata." + " Make sure you save your model with the `save_pretrained` method." + ) + safetensors_from_pt = safetensors_metadata.get("format") == "pt" + elif filename == SAFE_WEIGHTS_INDEX_NAME: + with safe_open(resolved_archive_file[0], framework="tf") as f: + safetensors_metadata = f.metadata() + if safetensors_metadata is None or safetensors_metadata.get("format") not in ["pt", "tf", "flax", "mlx"]: + raise OSError( + f"The safetensors archive passed at {resolved_archive_file} does not contain the valid metadata." + " Make sure you save your model with the `save_pretrained` method." + ) + safetensors_from_pt = safetensors_metadata.get("format") == "pt" + + config.name_or_path = pretrained_model_name_or_path + + # composed models, *e.g.* TFRag, require special treatment when it comes to loading + # pre-trained weights. + if cls._requires_load_weight_prefix and model_kwargs.get("name") is not None: + model_kwargs["load_weight_prefix"] = load_weight_prefix + "/" + model_kwargs.get("name") + + # Instantiate model. + model = cls(config, *model_args, **model_kwargs) + + if tf_to_pt_weight_rename is None and hasattr(model, "tf_to_pt_weight_rename"): + # TODO Matt: This is a temporary workaround to allow weight renaming, but requires a method + # to be defined for each class that requires a rename. We can probably just have a class-level + # dict and a single top-level method or something and cut down a lot of boilerplate code + tf_to_pt_weight_rename = model.tf_to_pt_weight_rename + + if from_pt: + from .modeling_tf_pytorch_utils import load_pytorch_checkpoint_in_tf2_model + + # Load from a PyTorch checkpoint + return load_pytorch_checkpoint_in_tf2_model( + model, + resolved_archive_file, + allow_missing_keys=True, + output_loading_info=output_loading_info, + _prefix=load_weight_prefix, + tf_to_pt_weight_rename=tf_to_pt_weight_rename, + ) + + # we might need to extend the variable scope for composite models + if load_weight_prefix is not None: + with tf.compat.v1.variable_scope(load_weight_prefix): + model.build_in_name_scope() # build the network with dummy inputs + else: + model.build_in_name_scope() # build the network with dummy inputs + + if safetensors_from_pt and not is_sharded: + from .modeling_tf_pytorch_utils import load_pytorch_state_dict_in_tf2_model + + with safe_open(resolved_archive_file, framework="tf") as safetensors_archive: + # Load from a PyTorch safetensors checkpoint + # We load in TF format here because PT weights often need to be transposed, and this is much + # faster on GPU. Loading as numpy and transposing on CPU adds several seconds to load times. + return load_pytorch_state_dict_in_tf2_model( + model, + safetensors_archive, + tf_inputs=False, # No need to build the model again + allow_missing_keys=True, + output_loading_info=output_loading_info, + _prefix=load_weight_prefix, + ignore_mismatched_sizes=ignore_mismatched_sizes, + tf_to_pt_weight_rename=tf_to_pt_weight_rename, + ) + elif safetensors_from_pt: + from .modeling_tf_pytorch_utils import load_sharded_pytorch_safetensors_in_tf2_model + + return load_sharded_pytorch_safetensors_in_tf2_model( + model, + resolved_archive_file, + tf_inputs=False, + allow_missing_keys=True, + output_loading_info=output_loading_info, + _prefix=load_weight_prefix, + ignore_mismatched_sizes=ignore_mismatched_sizes, + tf_to_pt_weight_rename=tf_to_pt_weight_rename, + ) + + # 'by_name' allow us to do transfer learning by skipping/adding layers + # see https://github.com/tensorflow/tensorflow/blob/00fad90125b18b80fe054de1055770cfb8fe4ba3/tensorflow/python/keras/engine/network.py#L1339-L1357 + try: + if is_sharded: + for file in resolved_archive_file: + os.path.isfile(file), f"Error retrieving files {file}" + if filename == SAFE_WEIGHTS_INDEX_NAME: + missing_keys, unexpected_keys, mismatched_keys = load_tf_sharded_weights_from_safetensors( + model, + resolved_archive_file, + ignore_mismatched_sizes=ignore_mismatched_sizes, + _prefix=load_weight_prefix, + ) + else: + missing_keys, unexpected_keys, mismatched_keys = load_tf_sharded_weights( + model, + resolved_archive_file, + ignore_mismatched_sizes=ignore_mismatched_sizes, + _prefix=load_weight_prefix, + ) + else: + # Handles both H5 and safetensors + missing_keys, unexpected_keys, mismatched_keys = load_tf_weights( + model, + resolved_archive_file, + ignore_mismatched_sizes=ignore_mismatched_sizes, + _prefix=load_weight_prefix, + ) + except OSError as e: + try: + with open(resolved_archive_file) as f: + if f.read().startswith("version"): + raise OSError( + "You seem to have cloned a repository without having git-lfs installed. Please install " + "git-lfs and run `git lfs install` followed by `git lfs pull` in the folder " + "you cloned." + ) + else: + raise ValueError from e + except (UnicodeDecodeError, ValueError): + raise OSError( + "Unable to load weights from h5 file. " + "If you tried to load a TF 2.0 model from a PyTorch checkpoint, please set from_pt=True. " + ) + + if cls._keys_to_ignore_on_load_missing is not None: + for pat in cls._keys_to_ignore_on_load_missing: + missing_keys = [k for k in missing_keys if re.search(pat, k) is None] + + if cls._keys_to_ignore_on_load_unexpected is not None: + for pat in cls._keys_to_ignore_on_load_unexpected: + unexpected_keys = [k for k in unexpected_keys if re.search(pat, k) is None] + + if len(unexpected_keys) > 0: + logger.warning( + f"Some layers from the model checkpoint at {pretrained_model_name_or_path} were not used when" + f" initializing {model.__class__.__name__}: {unexpected_keys}\n- This IS expected if you are" + f" initializing {model.__class__.__name__} from the checkpoint of a model trained on another task or" + " with another architecture (e.g. initializing a BertForSequenceClassification model from a" + " BertForPreTraining model).\n- This IS NOT expected if you are initializing" + f" {model.__class__.__name__} from the checkpoint of a model that you expect to be exactly identical" + " (initializing a BertForSequenceClassification model from a BertForSequenceClassification model)." + ) + else: + logger.warning(f"All model checkpoint layers were used when initializing {model.__class__.__name__}.\n") + + if len(missing_keys) > 0: + logger.warning( + f"Some layers of {model.__class__.__name__} were not initialized from the model checkpoint at" + f" {pretrained_model_name_or_path} and are newly initialized: {missing_keys}\nYou should probably" + " TRAIN this model on a down-stream task to be able to use it for predictions and inference." + ) + elif len(mismatched_keys) == 0: + logger.warning( + f"All the layers of {model.__class__.__name__} were initialized from the model checkpoint at" + f" {pretrained_model_name_or_path}.\nIf your task is similar to the task the model of the checkpoint" + f" was trained on, you can already use {model.__class__.__name__} for predictions without further" + " training." + ) + if len(mismatched_keys) > 0: + mismatched_warning = "\n".join( + [ + f"- {key}: found shape {shape1} in the checkpoint and {shape2} in the model instantiated" + for key, shape1, shape2 in mismatched_keys + ] + ) + logger.warning( + f"Some weights of {model.__class__.__name__} were not initialized from the model checkpoint at" + f" {pretrained_model_name_or_path} and are newly initialized because the shapes did not" + f" match:\n{mismatched_warning}\nYou should probably TRAIN this model on a down-stream task to be able" + " to use it for predictions and inference." + ) + + # If it is a model with generation capabilities, attempt to load the generation config + if model.can_generate(): + try: + model.generation_config = GenerationConfig.from_pretrained( + pretrained_model_name_or_path, + cache_dir=cache_dir, + force_download=force_download, + resume_download=resume_download, + proxies=proxies, + local_files_only=local_files_only, + token=token, + revision=revision, + subfolder=subfolder, + _from_auto=from_auto_class, + _from_pipeline=from_pipeline, + **kwargs, + ) + except OSError: + logger.info( + "Generation config file not found, using a generation config created from the model config." + ) + pass + + if output_loading_info: + loading_info = { + "missing_keys": missing_keys, + "unexpected_keys": unexpected_keys, + "mismatched_keys": mismatched_keys, + } + + return model, loading_info + + return model + + def push_to_hub( + self, + repo_id: str, + use_temp_dir: Optional[bool] = None, + commit_message: Optional[str] = None, + private: Optional[bool] = None, + max_shard_size: Optional[Union[int, str]] = "10GB", + token: Optional[Union[bool, str]] = None, + # (`use_auth_token` is deprecated: we have to keep it here as we don't have **kwargs) + use_auth_token: Optional[Union[bool, str]] = None, + create_pr: bool = False, + **base_model_card_args, + ) -> str: + """ + Upload the model files to the 🤗 Model Hub while synchronizing a local clone of the repo in `repo_path_or_name`. + + Parameters: + repo_id (`str`): + The name of the repository you want to push your model to. It should contain your organization name + when pushing to a given organization. + use_temp_dir (`bool`, *optional*): + Whether or not to use a temporary directory to store the files saved before they are pushed to the Hub. + Will default to `True` if there is no directory named like `repo_id`, `False` otherwise. + commit_message (`str`, *optional*): + Message to commit while pushing. Will default to `"Upload model"`. + private (`bool`, *optional*): + Whether or not the repository created should be private. + token (`bool` or `str`, *optional*): + The token to use as HTTP bearer authorization for remote files. If `True`, will use the token generated + when running `huggingface-cli login` (stored in `~/.huggingface`). Will default to `True` if `repo_url` + is not specified. + max_shard_size (`int` or `str`, *optional*, defaults to `"10GB"`): + Only applicable for models. The maximum size for a checkpoint before being sharded. Checkpoints shard + will then be each of size lower than this size. If expressed as a string, needs to be digits followed + by a unit (like `"5MB"`). + create_pr (`bool`, *optional*, defaults to `False`): + Whether or not to create a PR with the uploaded files or directly commit. + + Examples: + + ```python + from transformers import TFAutoModel + + model = TFAutoModel.from_pretrained("google-bert/bert-base-cased") + + # Push the model to your namespace with the name "my-finetuned-bert". + model.push_to_hub("my-finetuned-bert") + + # Push the model to an organization with the name "my-finetuned-bert". + model.push_to_hub("huggingface/my-finetuned-bert") + ``` + """ + if use_auth_token is not None: + warnings.warn( + "The `use_auth_token` argument is deprecated and will be removed in v5 of Transformers. Please use `token` instead.", + FutureWarning, + ) + if token is not None: + raise ValueError( + "`token` and `use_auth_token` are both specified. Please set only the argument `token`." + ) + token = use_auth_token + + if "repo_path_or_name" in base_model_card_args: + warnings.warn( + "The `repo_path_or_name` argument is deprecated and will be removed in v5 of Transformers. Use " + "`repo_id` instead." + ) + repo_id = base_model_card_args.pop("repo_path_or_name") + # Deprecation warning will be sent after for repo_url and organization + repo_url = base_model_card_args.pop("repo_url", None) + organization = base_model_card_args.pop("organization", None) + + if os.path.isdir(repo_id): + working_dir = repo_id + repo_id = repo_id.split(os.path.sep)[-1] + else: + working_dir = repo_id.split("/")[-1] + + repo_id = self._create_repo( + repo_id, private=private, token=token, repo_url=repo_url, organization=organization + ) + + if use_temp_dir is None: + use_temp_dir = not os.path.isdir(working_dir) + + with working_or_temp_dir(working_dir=working_dir, use_temp_dir=use_temp_dir) as work_dir: + files_timestamps = self._get_files_timestamps(work_dir) + + # Save all files. + self.save_pretrained(work_dir, max_shard_size=max_shard_size) + if hasattr(self, "history") and hasattr(self, "create_model_card"): + # This is a Keras model and we might be able to fish out its History and make a model card out of it + base_model_card_args = { + "output_dir": work_dir, + "model_name": Path(repo_id).name, + } + base_model_card_args.update(base_model_card_args) + self.create_model_card(**base_model_card_args) + + self._upload_modified_files( + work_dir, + repo_id, + files_timestamps, + commit_message=commit_message, + token=token, + create_pr=create_pr, + ) + + @classmethod + def register_for_auto_class(cls, auto_class="TFAutoModel"): + """ + Register this class with a given auto class. This should only be used for custom models as the ones in the + library are already mapped with an auto class. + + + + This API is experimental and may have some slight breaking changes in the next releases. + + + + Args: + auto_class (`str` or `type`, *optional*, defaults to `"TFAutoModel"`): + The auto class to register this new model with. + """ + if not isinstance(auto_class, str): + auto_class = auto_class.__name__ + + import transformers.models.auto as auto_module + + if not hasattr(auto_module, auto_class): + raise ValueError(f"{auto_class} is not a valid auto class.") + + cls._auto_class = auto_class + + +class TFConv1D(keras.layers.Layer): + """ + 1D-convolutional layer as defined by Radford et al. for OpenAI GPT (and also used in GPT-2). + + Basically works like a linear layer but the weights are transposed. + + Args: + nf (`int`): + The number of output features. + nx (`int`): + The number of input features. + initializer_range (`float`, *optional*, defaults to 0.02): + The standard deviation to use to initialize the weights. + kwargs (`Dict[str, Any]`, *optional*): + Additional keyword arguments passed along to the `__init__` of `keras.layers.Layer`. + """ + + def __init__(self, nf, nx, initializer_range=0.02, **kwargs): + super().__init__(**kwargs) + self.nf = nf + self.nx = nx + self.initializer_range = initializer_range + + def build(self, input_shape): + if self.built: + return + self.built = True + self.weight = self.add_weight( + "weight", shape=[self.nx, self.nf], initializer=get_initializer(self.initializer_range) + ) + self.bias = self.add_weight("bias", shape=[1, self.nf], initializer=tf.zeros_initializer()) + + def call(self, x): + bz, sl = shape_list(x)[:2] + + x = tf.reshape(x, [-1, self.nx]) + x = tf.matmul(x, self.weight) + self.bias + + x = tf.reshape(x, [bz, sl, self.nf]) + + return x + + +class TFSharedEmbeddings(keras.layers.Layer): + r""" + Construct shared token embeddings. + + The weights of the embedding layer is usually shared with the weights of the linear decoder when doing language + modeling. + + Args: + vocab_size (`int`): + The size of the vocabulary, e.g., the number of unique tokens. + hidden_size (`int`): + The size of the embedding vectors. + initializer_range (`float`, *optional*): + The standard deviation to use when initializing the weights. If no value is provided, it will default to + \\(1/\sqrt{hidden\_size}\\). + kwargs (`Dict[str, Any]`, *optional*): + Additional keyword arguments passed along to the `__init__` of `keras.layers.Layer`. + """ + + # TODO (joao): flagged for delection due to embeddings refactor + + def __init__(self, vocab_size: int, hidden_size: int, initializer_range: Optional[float] = None, **kwargs): + super().__init__(**kwargs) + self.vocab_size = vocab_size + self.hidden_size = hidden_size + self.initializer_range = hidden_size**-0.5 if initializer_range is None else initializer_range + warnings.warn( + "`TFSharedEmbeddings` is scheduled for deletion in v4.32, use `keras.layers.Embedding` instead.", + DeprecationWarning, + ) + + def build(self, input_shape): + """ + Build shared token embedding layer Shared weights logic adapted from + https://github.com/tensorflow/models/blob/a009f4fb9d2fc4949e32192a944688925ef78659/official/transformer/v2/embedding_layer.py#L24 + """ + self.weight = self.add_weight( + "weight", shape=[self.vocab_size, self.hidden_size], initializer=get_initializer(self.initializer_range) + ) + super().build(input_shape) + + def get_config(self): + config = { + "vocab_size": self.vocab_size, + "hidden_size": self.hidden_size, + "initializer_range": self.initializer_range, + } + base_config = super().get_config() + + return dict(list(base_config.items()) + list(config.items())) + + def call(self, inputs: tf.Tensor, mode: str = "embedding") -> tf.Tensor: + """ + Get token embeddings of inputs or decode final hidden state. + + Args: + inputs (`tf.Tensor`): + In embedding mode, should be an int64 tensor with shape `[batch_size, length]`. + + In linear mode, should be a float tensor with shape `[batch_size, length, hidden_size]`. + mode (`str`, defaults to `"embedding"`): + A valid value is either `"embedding"` or `"linear"`, the first one indicates that the layer should be + used as an embedding layer, the second one that the layer should be used as a linear decoder. + + Returns: + `tf.Tensor`: In embedding mode, the output is a float32 embedding tensor, with shape `[batch_size, length, + embedding_size]`. + + In linear mode, the output is a float32 with shape `[batch_size, length, vocab_size]`. + + Raises: + ValueError: if `mode` is not valid. + + Shared weights logic is adapted from + [here](https://github.com/tensorflow/models/blob/a009f4fb9d2fc4949e32192a944688925ef78659/official/transformer/v2/embedding_layer.py#L24). + """ + if mode == "embedding": + return self._embedding(inputs) + elif mode == "linear": + return self._linear(inputs) + else: + raise ValueError(f"mode {mode} is not valid.") + + def _embedding(self, input_ids): + """Applies embedding based on inputs tensor.""" + return tf.gather(self.weight, input_ids) + + def _linear(self, inputs): + """ + Computes logits by running inputs through a linear layer. + + Args: + inputs: A float32 tensor with shape [..., hidden_size] + + Returns: + float32 tensor with shape [..., vocab_size]. + """ + first_dims = shape_list(inputs)[:-1] + x = tf.reshape(inputs, [-1, self.hidden_size]) + logits = tf.matmul(x, self.weight, transpose_b=True) + + return tf.reshape(logits, first_dims + [self.vocab_size]) + + +class TFSequenceSummary(keras.layers.Layer): + """ + Compute a single vector summary of a sequence hidden states. + + Args: + config ([`PretrainedConfig`]): + The config used by the model. Relevant arguments in the config class of the model are (refer to the actual + config class of your model for the default values it uses): + + - **summary_type** (`str`) -- The method to use to make this summary. Accepted values are: + + - `"last"` -- Take the last token hidden state (like XLNet) + - `"first"` -- Take the first token hidden state (like Bert) + - `"mean"` -- Take the mean of all tokens hidden states + - `"cls_index"` -- Supply a Tensor of classification token position (GPT/GPT-2) + - `"attn"` -- Not implemented now, use multi-head attention + + - **summary_use_proj** (`bool`) -- Add a projection after the vector extraction. + - **summary_proj_to_labels** (`bool`) -- If `True`, the projection outputs to `config.num_labels` classes + (otherwise to `config.hidden_size`). + - **summary_activation** (`Optional[str]`) -- Set to `"tanh"` to add a tanh activation to the output, + another string or `None` will add no activation. + - **summary_first_dropout** (`float`) -- Optional dropout probability before the projection and activation. + - **summary_last_dropout** (`float`)-- Optional dropout probability after the projection and activation. + + initializer_range (`float`, defaults to 0.02): The standard deviation to use to initialize the weights. + kwargs (`Dict[str, Any]`, *optional*): + Additional keyword arguments passed along to the `__init__` of `keras.layers.Layer`. + """ + + def __init__(self, config: PretrainedConfig, initializer_range: float = 0.02, **kwargs): + super().__init__(**kwargs) + + self.summary_type = config.summary_type if hasattr(config, "summary_use_proj") else "last" + if self.summary_type == "attn": + # We should use a standard multi-head attention module with absolute positional embedding for that. + # Cf. https://github.com/zihangdai/xlnet/blob/master/modeling.py#L253-L276 + # We can probably just use the multi-head attention module of PyTorch >=1.1.0 + raise NotImplementedError + + self.has_summary = hasattr(config, "summary_use_proj") and config.summary_use_proj + if self.has_summary: + if hasattr(config, "summary_proj_to_labels") and config.summary_proj_to_labels and config.num_labels > 0: + num_classes = config.num_labels + else: + num_classes = config.hidden_size + self.summary = keras.layers.Dense( + num_classes, kernel_initializer=get_initializer(initializer_range), name="summary" + ) + + self.has_activation = False + activation_string = getattr(config, "summary_activation", None) + if activation_string is not None: + self.has_activation = True + self.activation = get_tf_activation(activation_string) + + self.has_first_dropout = hasattr(config, "summary_first_dropout") and config.summary_first_dropout > 0 + if self.has_first_dropout: + self.first_dropout = keras.layers.Dropout(config.summary_first_dropout) + + self.has_last_dropout = hasattr(config, "summary_last_dropout") and config.summary_last_dropout > 0 + if self.has_last_dropout: + self.last_dropout = keras.layers.Dropout(config.summary_last_dropout) + self.hidden_size = config.hidden_size + + def call(self, inputs, cls_index=None, training=False): + if not isinstance(inputs, (dict, tuple, list)): + hidden_states = inputs + elif isinstance(inputs, (tuple, list)): + hidden_states = inputs[0] + cls_index = inputs[1] if len(inputs) > 1 else None + assert len(inputs) <= 2, "Too many inputs." + else: + hidden_states = inputs.get("hidden_states") + cls_index = inputs.get("cls_index", None) + + if self.summary_type == "last": + output = hidden_states[:, -1] + elif self.summary_type == "first": + output = hidden_states[:, 0] + elif self.summary_type == "mean": + output = tf.reduce_mean(hidden_states, axis=1) + elif self.summary_type == "cls_index": + hidden_shape = shape_list(hidden_states) # e.g. [batch, num choices, seq length, hidden dims] + if cls_index is None: + cls_index = tf.fill( + hidden_shape[:-2], hidden_shape[-2] - 1 + ) # A tensor full of shape [batch] or [batch, num choices] full of sequence length + cls_shape = shape_list(cls_index) + if len(cls_shape) <= len(hidden_shape) - 2: + cls_index = tf.expand_dims(cls_index, axis=-1) + # else: + # cls_index = cls_index[..., tf.newaxis] + # cls_index = cls_index.expand((-1,) * (cls_index.dim()-1) + (hidden_states.size(-1),)) + # shape of cls_index: (bsz, XX, 1, hidden_size) where XX are optional leading dim of hidden_states + output = tf.gather(hidden_states, cls_index, batch_dims=len(hidden_shape) - 2) + output = tf.squeeze( + output, axis=len(hidden_shape) - 2 + ) # shape of output: (batch, num choices, hidden_size) + elif self.summary_type == "attn": + raise NotImplementedError + + if self.has_first_dropout: + output = self.first_dropout(output, training=training) + + if self.has_summary: + output = self.summary(output) + + if self.has_activation: + output = self.activation(output) + + if self.has_last_dropout: + output = self.last_dropout(output, training=training) + + return output + + def build(self, input_shape): + if self.built: + return + self.built = True + if getattr(self, "summary", None) is not None: + with tf.name_scope("summary"): + self.summary.build(self.hidden_size) + + +def get_initializer(initializer_range: float = 0.02) -> keras.initializers.TruncatedNormal: + """ + Creates a `keras.initializers.TruncatedNormal` with the given range. + + Args: + initializer_range (*float*, defaults to 0.02): Standard deviation of the initializer range. + + Returns: + `keras.initializers.TruncatedNormal`: The truncated normal initializer. + """ + return keras.initializers.TruncatedNormal(stddev=initializer_range)