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- # Copyright 2019 The Google AI Language Team Authors and The HuggingFace Inc. team.
- #
- # 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.
- """PyTorch ELECTRA model."""
- from collections.abc import Callable
- from dataclasses import dataclass
- import torch
- from torch import nn
- from torch.nn import BCEWithLogitsLoss, CrossEntropyLoss, MSELoss
- from ... import initialization as init
- from ...activations import ACT2FN, get_activation
- from ...cache_utils import Cache, DynamicCache, EncoderDecoderCache
- from ...generation import GenerationMixin
- from ...masking_utils import create_bidirectional_mask, create_causal_mask
- from ...modeling_layers import GradientCheckpointingLayer
- from ...modeling_outputs import (
- BaseModelOutputWithCrossAttentions,
- BaseModelOutputWithPastAndCrossAttentions,
- CausalLMOutputWithCrossAttentions,
- MaskedLMOutput,
- MultipleChoiceModelOutput,
- QuestionAnsweringModelOutput,
- SequenceClassifierOutput,
- TokenClassifierOutput,
- )
- from ...modeling_utils import ALL_ATTENTION_FUNCTIONS, PreTrainedModel
- from ...processing_utils import Unpack
- from ...pytorch_utils import apply_chunking_to_forward
- from ...utils import (
- ModelOutput,
- TransformersKwargs,
- auto_docstring,
- logging,
- )
- from ...utils.generic import can_return_tuple, merge_with_config_defaults
- from ...utils.output_capturing import capture_outputs
- from .configuration_electra import ElectraConfig
- logger = logging.get_logger(__name__)
- class ElectraEmbeddings(nn.Module):
- """Construct the embeddings from word, position and token_type embeddings."""
- def __init__(self, config):
- super().__init__()
- self.word_embeddings = nn.Embedding(config.vocab_size, config.embedding_size, padding_idx=config.pad_token_id)
- self.position_embeddings = nn.Embedding(config.max_position_embeddings, config.embedding_size)
- self.token_type_embeddings = nn.Embedding(config.type_vocab_size, config.embedding_size)
- self.LayerNorm = nn.LayerNorm(config.embedding_size, eps=config.layer_norm_eps)
- self.dropout = nn.Dropout(config.hidden_dropout_prob)
- # position_ids (1, len position emb) is contiguous in memory and exported when serialized
- self.register_buffer(
- "position_ids", torch.arange(config.max_position_embeddings).expand((1, -1)), persistent=False
- )
- self.register_buffer(
- "token_type_ids", torch.zeros(self.position_ids.size(), dtype=torch.long), persistent=False
- )
- # Copied from transformers.models.bert.modeling_bert.BertEmbeddings.forward
- def forward(
- self,
- input_ids: torch.LongTensor | None = None,
- token_type_ids: torch.LongTensor | None = None,
- position_ids: torch.LongTensor | None = None,
- inputs_embeds: torch.FloatTensor | None = None,
- past_key_values_length: int = 0,
- ) -> torch.Tensor:
- if input_ids is not None:
- input_shape = input_ids.size()
- else:
- input_shape = inputs_embeds.size()[:-1]
- batch_size, seq_length = input_shape
- if position_ids is None:
- position_ids = self.position_ids[:, past_key_values_length : seq_length + past_key_values_length]
- # Setting the token_type_ids to the registered buffer in constructor where it is all zeros, which usually occurs
- # when its auto-generated, registered buffer helps users when tracing the model without passing token_type_ids, solves
- # issue #5664
- if token_type_ids is None:
- if hasattr(self, "token_type_ids"):
- # NOTE: We assume either pos ids to have bsz == 1 (broadcastable) or bsz == effective bsz (input_shape[0])
- buffered_token_type_ids = self.token_type_ids.expand(position_ids.shape[0], -1)
- buffered_token_type_ids = torch.gather(buffered_token_type_ids, dim=1, index=position_ids)
- token_type_ids = buffered_token_type_ids.expand(batch_size, seq_length)
- else:
- token_type_ids = torch.zeros(input_shape, dtype=torch.long, device=self.position_ids.device)
- if inputs_embeds is None:
- inputs_embeds = self.word_embeddings(input_ids)
- token_type_embeddings = self.token_type_embeddings(token_type_ids)
- embeddings = inputs_embeds + token_type_embeddings
- position_embeddings = self.position_embeddings(position_ids)
- embeddings = embeddings + position_embeddings
- embeddings = self.LayerNorm(embeddings)
- embeddings = self.dropout(embeddings)
- return embeddings
- # Copied from transformers.models.bert.modeling_bert.eager_attention_forward
- def eager_attention_forward(
- module: nn.Module,
- query: torch.Tensor,
- key: torch.Tensor,
- value: torch.Tensor,
- attention_mask: torch.Tensor | None,
- scaling: float | None = None,
- dropout: float = 0.0,
- **kwargs: Unpack[TransformersKwargs],
- ):
- if scaling is None:
- scaling = query.size(-1) ** -0.5
- # Take the dot product between "query" and "key" to get the raw attention scores.
- attn_weights = torch.matmul(query, key.transpose(2, 3)) * scaling
- if attention_mask is not None:
- attn_weights = attn_weights + attention_mask
- attn_weights = nn.functional.softmax(attn_weights, dim=-1)
- attn_weights = nn.functional.dropout(attn_weights, p=dropout, training=module.training)
- attn_output = torch.matmul(attn_weights, value)
- attn_output = attn_output.transpose(1, 2).contiguous()
- return attn_output, attn_weights
- # Copied from transformers.models.bert.modeling_bert.BertSelfAttention with Bert->Electra
- class ElectraSelfAttention(nn.Module):
- def __init__(self, config, is_causal=False, layer_idx=None):
- super().__init__()
- if config.hidden_size % config.num_attention_heads != 0 and not hasattr(config, "embedding_size"):
- raise ValueError(
- f"The hidden size ({config.hidden_size}) is not a multiple of the number of attention "
- f"heads ({config.num_attention_heads})"
- )
- self.config = config
- self.num_attention_heads = config.num_attention_heads
- self.attention_head_size = int(config.hidden_size / config.num_attention_heads)
- self.all_head_size = self.num_attention_heads * self.attention_head_size
- self.scaling = self.attention_head_size**-0.5
- self.query = nn.Linear(config.hidden_size, self.all_head_size)
- self.key = nn.Linear(config.hidden_size, self.all_head_size)
- self.value = nn.Linear(config.hidden_size, self.all_head_size)
- self.dropout = nn.Dropout(config.attention_probs_dropout_prob)
- self.is_decoder = config.is_decoder
- self.is_causal = is_causal
- self.layer_idx = layer_idx
- def forward(
- self,
- hidden_states: torch.Tensor,
- attention_mask: torch.FloatTensor | None = None,
- past_key_values: Cache | None = None,
- **kwargs: Unpack[TransformersKwargs],
- ) -> tuple[torch.Tensor]:
- input_shape = hidden_states.shape[:-1]
- hidden_shape = (*input_shape, -1, self.attention_head_size)
- # get all proj
- query_layer = self.query(hidden_states).view(*hidden_shape).transpose(1, 2)
- key_layer = self.key(hidden_states).view(*hidden_shape).transpose(1, 2)
- value_layer = self.value(hidden_states).view(*hidden_shape).transpose(1, 2)
- if past_key_values is not None:
- # decoder-only bert can have a simple dynamic cache for example
- current_past_key_values = past_key_values
- if isinstance(past_key_values, EncoderDecoderCache):
- current_past_key_values = past_key_values.self_attention_cache
- # save all key/value_layer to cache to be re-used for fast auto-regressive generation
- key_layer, value_layer = current_past_key_values.update(key_layer, value_layer, self.layer_idx)
- attention_interface: Callable = ALL_ATTENTION_FUNCTIONS.get_interface(
- self.config._attn_implementation, eager_attention_forward
- )
- attn_output, attn_weights = attention_interface(
- self,
- query_layer,
- key_layer,
- value_layer,
- attention_mask,
- dropout=0.0 if not self.training else self.dropout.p,
- scaling=self.scaling,
- **kwargs,
- )
- attn_output = attn_output.reshape(*input_shape, -1).contiguous()
- return attn_output, attn_weights
- # Copied from transformers.models.bert.modeling_bert.BertCrossAttention with Bert->Electra
- class ElectraCrossAttention(nn.Module):
- def __init__(self, config, is_causal=False, layer_idx=None):
- super().__init__()
- if config.hidden_size % config.num_attention_heads != 0 and not hasattr(config, "embedding_size"):
- raise ValueError(
- f"The hidden size ({config.hidden_size}) is not a multiple of the number of attention "
- f"heads ({config.num_attention_heads})"
- )
- self.config = config
- self.num_attention_heads = config.num_attention_heads
- self.attention_head_size = int(config.hidden_size / config.num_attention_heads)
- self.all_head_size = self.num_attention_heads * self.attention_head_size
- self.scaling = self.attention_head_size**-0.5
- self.query = nn.Linear(config.hidden_size, self.all_head_size)
- self.key = nn.Linear(config.hidden_size, self.all_head_size)
- self.value = nn.Linear(config.hidden_size, self.all_head_size)
- self.dropout = nn.Dropout(config.attention_probs_dropout_prob)
- self.is_causal = is_causal
- self.layer_idx = layer_idx
- def forward(
- self,
- hidden_states: torch.Tensor,
- encoder_hidden_states: torch.FloatTensor | None = None,
- attention_mask: torch.FloatTensor | None = None,
- past_key_values: EncoderDecoderCache | None = None,
- **kwargs: Unpack[TransformersKwargs],
- ) -> tuple[torch.Tensor]:
- # determine input shapes
- input_shape = hidden_states.shape[:-1]
- hidden_shape = (*input_shape, -1, self.attention_head_size)
- # get query proj
- query_layer = self.query(hidden_states).view(hidden_shape).transpose(1, 2)
- is_updated = past_key_values.is_updated.get(self.layer_idx) if past_key_values is not None else False
- if past_key_values is not None and is_updated:
- # reuse k,v, cross_attentions
- key_layer = past_key_values.cross_attention_cache.layers[self.layer_idx].keys
- value_layer = past_key_values.cross_attention_cache.layers[self.layer_idx].values
- else:
- kv_shape = (*encoder_hidden_states.shape[:-1], -1, self.attention_head_size)
- key_layer = self.key(encoder_hidden_states).view(kv_shape).transpose(1, 2)
- value_layer = self.value(encoder_hidden_states).view(kv_shape).transpose(1, 2)
- if past_key_values is not None:
- # save all states to the cache
- key_layer, value_layer = past_key_values.cross_attention_cache.update(
- key_layer, value_layer, self.layer_idx
- )
- # set flag that curr layer for cross-attn is already updated so we can re-use in subsequent calls
- past_key_values.is_updated[self.layer_idx] = True
- attention_interface: Callable = ALL_ATTENTION_FUNCTIONS.get_interface(
- self.config._attn_implementation, eager_attention_forward
- )
- attn_output, attn_weights = attention_interface(
- self,
- query_layer,
- key_layer,
- value_layer,
- attention_mask,
- dropout=0.0 if not self.training else self.dropout.p,
- scaling=self.scaling,
- **kwargs,
- )
- attn_output = attn_output.reshape(*input_shape, -1).contiguous()
- return attn_output, attn_weights
- # Copied from transformers.models.bert.modeling_bert.BertSelfOutput
- class ElectraSelfOutput(nn.Module):
- def __init__(self, config):
- super().__init__()
- self.dense = nn.Linear(config.hidden_size, config.hidden_size)
- self.LayerNorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps)
- self.dropout = nn.Dropout(config.hidden_dropout_prob)
- def forward(self, hidden_states: torch.Tensor, input_tensor: torch.Tensor) -> torch.Tensor:
- hidden_states = self.dense(hidden_states)
- hidden_states = self.dropout(hidden_states)
- hidden_states = self.LayerNorm(hidden_states + input_tensor)
- return hidden_states
- # Copied from transformers.models.bert.modeling_bert.BertAttention with Bert->Electra,BERT->ELECTRA
- class ElectraAttention(nn.Module):
- def __init__(self, config, is_causal=False, layer_idx=None, is_cross_attention=False):
- super().__init__()
- self.is_cross_attention = is_cross_attention
- attention_class = ElectraCrossAttention if is_cross_attention else ElectraSelfAttention
- self.self = attention_class(config, is_causal=is_causal, layer_idx=layer_idx)
- self.output = ElectraSelfOutput(config)
- def forward(
- self,
- hidden_states: torch.Tensor,
- attention_mask: torch.FloatTensor | None = None,
- encoder_hidden_states: torch.FloatTensor | None = None,
- encoder_attention_mask: torch.FloatTensor | None = None,
- past_key_values: Cache | None = None,
- **kwargs: Unpack[TransformersKwargs],
- ) -> tuple[torch.Tensor]:
- attention_mask = attention_mask if not self.is_cross_attention else encoder_attention_mask
- attention_output, attn_weights = self.self(
- hidden_states,
- encoder_hidden_states=encoder_hidden_states,
- attention_mask=attention_mask,
- past_key_values=past_key_values,
- **kwargs,
- )
- attention_output = self.output(attention_output, hidden_states)
- return attention_output, attn_weights
- # Copied from transformers.models.bert.modeling_bert.BertIntermediate
- class ElectraIntermediate(nn.Module):
- def __init__(self, config):
- super().__init__()
- self.dense = nn.Linear(config.hidden_size, config.intermediate_size)
- if isinstance(config.hidden_act, str):
- self.intermediate_act_fn = ACT2FN[config.hidden_act]
- else:
- self.intermediate_act_fn = config.hidden_act
- def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
- hidden_states = self.dense(hidden_states)
- hidden_states = self.intermediate_act_fn(hidden_states)
- return hidden_states
- # Copied from transformers.models.bert.modeling_bert.BertOutput
- class ElectraOutput(nn.Module):
- def __init__(self, config):
- super().__init__()
- self.dense = nn.Linear(config.intermediate_size, config.hidden_size)
- self.LayerNorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps)
- self.dropout = nn.Dropout(config.hidden_dropout_prob)
- def forward(self, hidden_states: torch.Tensor, input_tensor: torch.Tensor) -> torch.Tensor:
- hidden_states = self.dense(hidden_states)
- hidden_states = self.dropout(hidden_states)
- hidden_states = self.LayerNorm(hidden_states + input_tensor)
- return hidden_states
- # Copied from transformers.models.bert.modeling_bert.BertLayer with Bert->Electra
- class ElectraLayer(GradientCheckpointingLayer):
- def __init__(self, config, layer_idx=None):
- super().__init__()
- self.chunk_size_feed_forward = config.chunk_size_feed_forward
- self.seq_len_dim = 1
- self.attention = ElectraAttention(config, is_causal=config.is_decoder, layer_idx=layer_idx)
- self.is_decoder = config.is_decoder
- self.add_cross_attention = config.add_cross_attention
- if self.add_cross_attention:
- if not self.is_decoder:
- raise ValueError(f"{self} should be used as a decoder model if cross attention is added")
- self.crossattention = ElectraAttention(
- config,
- is_causal=False,
- layer_idx=layer_idx,
- is_cross_attention=True,
- )
- self.intermediate = ElectraIntermediate(config)
- self.output = ElectraOutput(config)
- def forward(
- self,
- hidden_states: torch.Tensor,
- attention_mask: torch.FloatTensor | None = None,
- encoder_hidden_states: torch.FloatTensor | None = None,
- encoder_attention_mask: torch.FloatTensor | None = None,
- past_key_values: Cache | None = None,
- **kwargs: Unpack[TransformersKwargs],
- ) -> torch.Tensor:
- self_attention_output, _ = self.attention(
- hidden_states,
- attention_mask,
- past_key_values=past_key_values,
- **kwargs,
- )
- attention_output = self_attention_output
- if self.is_decoder and encoder_hidden_states is not None:
- if not hasattr(self, "crossattention"):
- raise ValueError(
- f"If `encoder_hidden_states` are passed, {self} has to be instantiated with cross-attention layers"
- " by setting `config.add_cross_attention=True`"
- )
- cross_attention_output, _ = self.crossattention(
- self_attention_output,
- None, # attention_mask
- encoder_hidden_states,
- encoder_attention_mask,
- past_key_values=past_key_values,
- **kwargs,
- )
- attention_output = cross_attention_output
- layer_output = apply_chunking_to_forward(
- self.feed_forward_chunk, self.chunk_size_feed_forward, self.seq_len_dim, attention_output
- )
- return layer_output
- def feed_forward_chunk(self, attention_output):
- intermediate_output = self.intermediate(attention_output)
- layer_output = self.output(intermediate_output, attention_output)
- return layer_output
- # Copied from transformers.models.bert.modeling_bert.BertEncoder with Bert->Electra
- class ElectraEncoder(nn.Module):
- def __init__(self, config):
- super().__init__()
- self.config = config
- self.layer = nn.ModuleList([ElectraLayer(config, layer_idx=i) for i in range(config.num_hidden_layers)])
- def forward(
- self,
- hidden_states: torch.Tensor,
- attention_mask: torch.FloatTensor | None = None,
- encoder_hidden_states: torch.FloatTensor | None = None,
- encoder_attention_mask: torch.FloatTensor | None = None,
- past_key_values: Cache | None = None,
- use_cache: bool | None = None,
- **kwargs: Unpack[TransformersKwargs],
- ) -> tuple[torch.Tensor] | BaseModelOutputWithPastAndCrossAttentions:
- for i, layer_module in enumerate(self.layer):
- hidden_states = layer_module(
- hidden_states,
- attention_mask,
- encoder_hidden_states, # as a positional argument for gradient checkpointing
- encoder_attention_mask=encoder_attention_mask,
- past_key_values=past_key_values,
- **kwargs,
- )
- return BaseModelOutputWithPastAndCrossAttentions(
- last_hidden_state=hidden_states,
- past_key_values=past_key_values if use_cache else None,
- )
- class ElectraDiscriminatorPredictions(nn.Module):
- """Prediction module for the discriminator, made up of two dense layers."""
- def __init__(self, config):
- super().__init__()
- self.dense = nn.Linear(config.hidden_size, config.hidden_size)
- self.activation = get_activation(config.hidden_act)
- self.dense_prediction = nn.Linear(config.hidden_size, 1)
- self.config = config
- def forward(self, discriminator_hidden_states):
- hidden_states = self.dense(discriminator_hidden_states)
- hidden_states = self.activation(hidden_states)
- logits = self.dense_prediction(hidden_states).squeeze(-1)
- return logits
- class ElectraGeneratorPredictions(nn.Module):
- """Prediction module for the generator, made up of two dense layers."""
- def __init__(self, config):
- super().__init__()
- self.activation = get_activation("gelu")
- self.LayerNorm = nn.LayerNorm(config.embedding_size, eps=config.layer_norm_eps)
- self.dense = nn.Linear(config.hidden_size, config.embedding_size)
- def forward(self, generator_hidden_states):
- hidden_states = self.dense(generator_hidden_states)
- hidden_states = self.activation(hidden_states)
- hidden_states = self.LayerNorm(hidden_states)
- return hidden_states
- @auto_docstring
- class ElectraPreTrainedModel(PreTrainedModel):
- config_class = ElectraConfig
- base_model_prefix = "electra"
- supports_gradient_checkpointing = True
- _supports_flash_attn = True
- _supports_sdpa = True
- _supports_flex_attn = True
- _supports_attention_backend = True
- _can_record_outputs = {
- "hidden_states": ElectraLayer,
- "attentions": ElectraSelfAttention,
- "cross_attentions": ElectraCrossAttention,
- }
- def _init_weights(self, module):
- super()._init_weights(module)
- if isinstance(module, ElectraEmbeddings):
- init.copy_(module.position_ids, torch.arange(module.position_ids.shape[-1]).expand((1, -1)))
- init.zeros_(module.token_type_ids)
- @dataclass
- @auto_docstring(
- custom_intro="""
- Output type of [`ElectraForPreTraining`].
- """
- )
- class ElectraForPreTrainingOutput(ModelOutput):
- r"""
- loss (*optional*, returned when `labels` is provided, `torch.FloatTensor` of shape `(1,)`):
- Total loss of the ELECTRA objective.
- logits (`torch.FloatTensor` of shape `(batch_size, sequence_length)`):
- Prediction scores of the head (scores for each token before SoftMax).
- """
- loss: torch.FloatTensor | None = None
- logits: torch.FloatTensor | None = None
- hidden_states: tuple[torch.FloatTensor] | None = None
- attentions: tuple[torch.FloatTensor] | None = None
- @auto_docstring
- class ElectraModel(ElectraPreTrainedModel):
- def __init__(self, config):
- super().__init__(config)
- self.embeddings = ElectraEmbeddings(config)
- if config.embedding_size != config.hidden_size:
- self.embeddings_project = nn.Linear(config.embedding_size, config.hidden_size)
- self.encoder = ElectraEncoder(config)
- self.config = config
- self.gradient_checkpointing = False
- # Initialize weights and apply final processing
- self.post_init()
- def get_input_embeddings(self):
- return self.embeddings.word_embeddings
- def set_input_embeddings(self, value):
- self.embeddings.word_embeddings = value
- @merge_with_config_defaults
- @capture_outputs
- @auto_docstring
- def forward(
- self,
- input_ids: torch.Tensor | None = None,
- attention_mask: torch.Tensor | None = None,
- token_type_ids: torch.Tensor | None = None,
- position_ids: torch.Tensor | None = None,
- inputs_embeds: torch.Tensor | None = None,
- encoder_hidden_states: torch.Tensor | None = None,
- encoder_attention_mask: torch.Tensor | None = None,
- past_key_values: list[torch.FloatTensor] | None = None,
- use_cache: bool | None = None,
- **kwargs: Unpack[TransformersKwargs],
- ) -> tuple[torch.Tensor] | BaseModelOutputWithCrossAttentions:
- if (input_ids is None) ^ (inputs_embeds is not None):
- raise ValueError("You must specify exactly one of input_ids or inputs_embeds")
- if self.config.is_decoder:
- use_cache = use_cache if use_cache is not None else self.config.use_cache
- else:
- use_cache = False
- if use_cache and past_key_values is None:
- past_key_values = (
- EncoderDecoderCache(DynamicCache(config=self.config), DynamicCache(config=self.config))
- if encoder_hidden_states is not None or self.config.is_encoder_decoder
- else DynamicCache(config=self.config)
- )
- past_key_values_length = past_key_values.get_seq_length() if past_key_values is not None else 0
- embedding_output = self.embeddings(
- input_ids=input_ids,
- position_ids=position_ids,
- token_type_ids=token_type_ids,
- inputs_embeds=inputs_embeds,
- past_key_values_length=past_key_values_length,
- )
- if hasattr(self, "embeddings_project"):
- embedding_output = self.embeddings_project(embedding_output)
- attention_mask, encoder_attention_mask = self._create_attention_masks(
- attention_mask=attention_mask,
- encoder_attention_mask=encoder_attention_mask,
- embedding_output=embedding_output,
- encoder_hidden_states=encoder_hidden_states,
- past_key_values=past_key_values,
- )
- encoder_outputs = self.encoder(
- embedding_output,
- attention_mask=attention_mask,
- encoder_hidden_states=encoder_hidden_states,
- encoder_attention_mask=encoder_attention_mask,
- past_key_values=past_key_values,
- use_cache=use_cache,
- position_ids=position_ids,
- **kwargs,
- )
- return BaseModelOutputWithPastAndCrossAttentions(
- last_hidden_state=encoder_outputs.last_hidden_state,
- past_key_values=encoder_outputs.past_key_values,
- )
- # Copied from transformers.models.bert.modeling_bert.BertModel._create_attention_masks
- def _create_attention_masks(
- self,
- attention_mask,
- encoder_attention_mask,
- embedding_output,
- encoder_hidden_states,
- past_key_values,
- ):
- if self.config.is_decoder:
- attention_mask = create_causal_mask(
- config=self.config,
- inputs_embeds=embedding_output,
- attention_mask=attention_mask,
- past_key_values=past_key_values,
- )
- else:
- attention_mask = create_bidirectional_mask(
- config=self.config,
- inputs_embeds=embedding_output,
- attention_mask=attention_mask,
- )
- if encoder_attention_mask is not None:
- encoder_attention_mask = create_bidirectional_mask(
- config=self.config,
- inputs_embeds=embedding_output,
- attention_mask=encoder_attention_mask,
- encoder_hidden_states=encoder_hidden_states,
- )
- return attention_mask, encoder_attention_mask
- class ElectraClassificationHead(nn.Module):
- """Head for sentence-level classification tasks."""
- def __init__(self, config):
- super().__init__()
- self.dense = nn.Linear(config.hidden_size, config.hidden_size)
- classifier_dropout = (
- config.classifier_dropout if config.classifier_dropout is not None else config.hidden_dropout_prob
- )
- self.activation = get_activation("gelu")
- self.dropout = nn.Dropout(classifier_dropout)
- self.out_proj = nn.Linear(config.hidden_size, config.num_labels)
- def forward(self, features, **kwargs):
- x = features[:, 0, :] # take <s> token (equiv. to [CLS])
- x = self.dropout(x)
- x = self.dense(x)
- x = self.activation(x) # although BERT uses tanh here, it seems Electra authors used gelu here
- x = self.dropout(x)
- x = self.out_proj(x)
- return x
- # Copied from transformers.models.xlm.modeling_xlm.XLMSequenceSummary with XLM->Electra
- class ElectraSequenceSummary(nn.Module):
- r"""
- Compute a single vector summary of a sequence hidden states.
- Args:
- config ([`ElectraConfig`]):
- 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.
- """
- def __init__(self, config: ElectraConfig):
- super().__init__()
- self.summary_type = getattr(config, "summary_type", "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.summary = nn.Identity()
- if hasattr(config, "summary_use_proj") and config.summary_use_proj:
- 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 = nn.Linear(config.hidden_size, num_classes)
- activation_string = getattr(config, "summary_activation", None)
- self.activation: Callable = get_activation(activation_string) if activation_string else nn.Identity()
- self.first_dropout = nn.Identity()
- if hasattr(config, "summary_first_dropout") and config.summary_first_dropout > 0:
- self.first_dropout = nn.Dropout(config.summary_first_dropout)
- self.last_dropout = nn.Identity()
- if hasattr(config, "summary_last_dropout") and config.summary_last_dropout > 0:
- self.last_dropout = nn.Dropout(config.summary_last_dropout)
- def forward(
- self, hidden_states: torch.FloatTensor, cls_index: torch.LongTensor | None = None
- ) -> torch.FloatTensor:
- """
- Compute a single vector summary of a sequence hidden states.
- Args:
- hidden_states (`torch.FloatTensor` of shape `[batch_size, seq_len, hidden_size]`):
- The hidden states of the last layer.
- cls_index (`torch.LongTensor` of shape `[batch_size]` or `[batch_size, ...]` where ... are optional leading dimensions of `hidden_states`, *optional*):
- Used if `summary_type == "cls_index"` and takes the last token of the sequence as classification token.
- Returns:
- `torch.FloatTensor`: The summary of the sequence hidden states.
- """
- if self.summary_type == "last":
- output = hidden_states[:, -1]
- elif self.summary_type == "first":
- output = hidden_states[:, 0]
- elif self.summary_type == "mean":
- output = hidden_states.mean(dim=1)
- elif self.summary_type == "cls_index":
- if cls_index is None:
- cls_index = torch.full_like(
- hidden_states[..., :1, :],
- hidden_states.shape[-2] - 1,
- dtype=torch.long,
- )
- else:
- cls_index = cls_index.unsqueeze(-1).unsqueeze(-1)
- 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 = hidden_states.gather(-2, cls_index).squeeze(-2) # shape (bsz, XX, hidden_size)
- elif self.summary_type == "attn":
- raise NotImplementedError
- output = self.first_dropout(output)
- output = self.summary(output)
- output = self.activation(output)
- output = self.last_dropout(output)
- return output
- @auto_docstring(
- custom_intro="""
- ELECTRA Model transformer with a sequence classification/regression head on top (a linear layer on top of the
- pooled output) e.g. for GLUE tasks.
- """
- )
- class ElectraForSequenceClassification(ElectraPreTrainedModel):
- def __init__(self, config):
- super().__init__(config)
- self.num_labels = config.num_labels
- self.config = config
- self.electra = ElectraModel(config)
- self.classifier = ElectraClassificationHead(config)
- # Initialize weights and apply final processing
- self.post_init()
- @can_return_tuple
- @auto_docstring
- def forward(
- self,
- input_ids: torch.Tensor | None = None,
- attention_mask: torch.Tensor | None = None,
- token_type_ids: torch.Tensor | None = None,
- position_ids: torch.Tensor | None = None,
- inputs_embeds: torch.Tensor | None = None,
- labels: torch.Tensor | None = None,
- **kwargs: Unpack[TransformersKwargs],
- ) -> tuple[torch.Tensor] | SequenceClassifierOutput:
- r"""
- labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
- Labels for computing the sequence classification/regression loss. Indices should be in `[0, ...,
- config.num_labels - 1]`. If `config.num_labels == 1` a regression loss is computed (Mean-Square loss), If
- `config.num_labels > 1` a classification loss is computed (Cross-Entropy).
- """
- discriminator_hidden_states = self.electra(
- input_ids,
- attention_mask=attention_mask,
- token_type_ids=token_type_ids,
- position_ids=position_ids,
- inputs_embeds=inputs_embeds,
- return_dict=True,
- **kwargs,
- )
- sequence_output = discriminator_hidden_states[0]
- logits = self.classifier(sequence_output)
- loss = None
- if labels is not None:
- if self.config.problem_type is None:
- if self.num_labels == 1:
- self.config.problem_type = "regression"
- elif self.num_labels > 1 and (labels.dtype == torch.long or labels.dtype == torch.int):
- self.config.problem_type = "single_label_classification"
- else:
- self.config.problem_type = "multi_label_classification"
- if self.config.problem_type == "regression":
- loss_fct = MSELoss()
- if self.num_labels == 1:
- loss = loss_fct(logits.squeeze(), labels.squeeze())
- else:
- loss = loss_fct(logits, labels)
- elif self.config.problem_type == "single_label_classification":
- loss_fct = CrossEntropyLoss()
- loss = loss_fct(logits.view(-1, self.num_labels), labels.view(-1))
- elif self.config.problem_type == "multi_label_classification":
- loss_fct = BCEWithLogitsLoss()
- loss = loss_fct(logits, labels)
- return SequenceClassifierOutput(
- loss=loss,
- logits=logits,
- hidden_states=discriminator_hidden_states.hidden_states,
- attentions=discriminator_hidden_states.attentions,
- )
- @auto_docstring(
- custom_intro="""
- Electra model with a binary classification head on top as used during pretraining for identifying generated tokens.
- It is recommended to load the discriminator checkpoint into that model.
- """
- )
- class ElectraForPreTraining(ElectraPreTrainedModel):
- def __init__(self, config):
- super().__init__(config)
- self.electra = ElectraModel(config)
- self.discriminator_predictions = ElectraDiscriminatorPredictions(config)
- # Initialize weights and apply final processing
- self.post_init()
- @can_return_tuple
- @auto_docstring
- def forward(
- self,
- input_ids: torch.Tensor | None = None,
- attention_mask: torch.Tensor | None = None,
- token_type_ids: torch.Tensor | None = None,
- position_ids: torch.Tensor | None = None,
- inputs_embeds: torch.Tensor | None = None,
- labels: torch.Tensor | None = None,
- **kwargs: Unpack[TransformersKwargs],
- ) -> tuple[torch.Tensor] | ElectraForPreTrainingOutput:
- r"""
- labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
- Labels for computing the ELECTRA loss. Input should be a sequence of tokens (see `input_ids` docstring)
- Indices should be in `[0, 1]`:
- - 0 indicates the token is an original token,
- - 1 indicates the token was replaced.
- Examples:
- ```python
- >>> from transformers import ElectraForPreTraining, AutoTokenizer
- >>> import torch
- >>> discriminator = ElectraForPreTraining.from_pretrained("google/electra-base-discriminator")
- >>> tokenizer = AutoTokenizer.from_pretrained("google/electra-base-discriminator")
- >>> sentence = "The quick brown fox jumps over the lazy dog"
- >>> fake_sentence = "The quick brown fox fake over the lazy dog"
- >>> fake_tokens = tokenizer.tokenize(fake_sentence, add_special_tokens=True)
- >>> fake_inputs = tokenizer.encode(fake_sentence, return_tensors="pt")
- >>> discriminator_outputs = discriminator(fake_inputs)
- >>> predictions = torch.round((torch.sign(discriminator_outputs[0]) + 1) / 2)
- >>> fake_tokens
- ['[CLS]', 'the', 'quick', 'brown', 'fox', 'fake', 'over', 'the', 'lazy', 'dog', '[SEP]']
- >>> predictions.squeeze().tolist()
- [0.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 0.0]
- ```"""
- discriminator_hidden_states = self.electra(
- input_ids,
- attention_mask=attention_mask,
- token_type_ids=token_type_ids,
- position_ids=position_ids,
- inputs_embeds=inputs_embeds,
- return_dict=True,
- **kwargs,
- )
- discriminator_sequence_output = discriminator_hidden_states[0]
- logits = self.discriminator_predictions(discriminator_sequence_output)
- loss = None
- if labels is not None:
- loss_fct = nn.BCEWithLogitsLoss()
- if attention_mask is not None:
- active_loss = attention_mask.view(-1, discriminator_sequence_output.shape[1]) == 1
- active_logits = logits.view(-1, discriminator_sequence_output.shape[1])[active_loss]
- active_labels = labels[active_loss]
- loss = loss_fct(active_logits, active_labels.float())
- else:
- loss = loss_fct(logits.view(-1, discriminator_sequence_output.shape[1]), labels.float())
- return ElectraForPreTrainingOutput(
- loss=loss,
- logits=logits,
- hidden_states=discriminator_hidden_states.hidden_states,
- attentions=discriminator_hidden_states.attentions,
- )
- @auto_docstring(
- custom_intro="""
- Electra model with a language modeling head on top.
- Even though both the discriminator and generator may be loaded into this model, the generator is the only model of
- the two to have been trained for the masked language modeling task.
- """
- )
- class ElectraForMaskedLM(ElectraPreTrainedModel):
- _tied_weights_keys = {"generator_lm_head.weight": "electra.embeddings.word_embeddings.weight"}
- def __init__(self, config):
- super().__init__(config)
- self.electra = ElectraModel(config)
- self.generator_predictions = ElectraGeneratorPredictions(config)
- self.generator_lm_head = nn.Linear(config.embedding_size, config.vocab_size)
- # Initialize weights and apply final processing
- self.post_init()
- def get_output_embeddings(self):
- return self.generator_lm_head
- def set_output_embeddings(self, word_embeddings):
- self.generator_lm_head = word_embeddings
- @can_return_tuple
- @auto_docstring
- def forward(
- self,
- input_ids: torch.Tensor | None = None,
- attention_mask: torch.Tensor | None = None,
- token_type_ids: torch.Tensor | None = None,
- position_ids: torch.Tensor | None = None,
- inputs_embeds: torch.Tensor | None = None,
- labels: torch.Tensor | None = None,
- **kwargs: Unpack[TransformersKwargs],
- ) -> tuple[torch.Tensor] | MaskedLMOutput:
- r"""
- labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
- Labels for computing the masked language modeling loss. Indices should be in `[-100, 0, ...,
- config.vocab_size]` (see `input_ids` docstring) Tokens with indices set to `-100` are ignored (masked), the
- loss is only computed for the tokens with labels in `[0, ..., config.vocab_size]`
- """
- generator_hidden_states = self.electra(
- input_ids,
- attention_mask=attention_mask,
- token_type_ids=token_type_ids,
- position_ids=position_ids,
- inputs_embeds=inputs_embeds,
- return_dict=True,
- **kwargs,
- )
- generator_sequence_output = generator_hidden_states[0]
- prediction_scores = self.generator_predictions(generator_sequence_output)
- prediction_scores = self.generator_lm_head(prediction_scores)
- loss = None
- # Masked language modeling softmax layer
- if labels is not None:
- loss_fct = nn.CrossEntropyLoss() # -100 index = padding token
- loss = loss_fct(prediction_scores.view(-1, self.config.vocab_size), labels.view(-1))
- return MaskedLMOutput(
- loss=loss,
- logits=prediction_scores,
- hidden_states=generator_hidden_states.hidden_states,
- attentions=generator_hidden_states.attentions,
- )
- @auto_docstring(
- custom_intro="""
- Electra model with a token classification head on top.
- Both the discriminator and generator may be loaded into this model.
- """
- )
- class ElectraForTokenClassification(ElectraPreTrainedModel):
- def __init__(self, config):
- super().__init__(config)
- self.num_labels = config.num_labels
- self.electra = ElectraModel(config)
- classifier_dropout = (
- config.classifier_dropout if config.classifier_dropout is not None else config.hidden_dropout_prob
- )
- self.dropout = nn.Dropout(classifier_dropout)
- self.classifier = nn.Linear(config.hidden_size, config.num_labels)
- # Initialize weights and apply final processing
- self.post_init()
- @can_return_tuple
- @auto_docstring
- def forward(
- self,
- input_ids: torch.Tensor | None = None,
- attention_mask: torch.Tensor | None = None,
- token_type_ids: torch.Tensor | None = None,
- position_ids: torch.Tensor | None = None,
- inputs_embeds: torch.Tensor | None = None,
- labels: torch.Tensor | None = None,
- **kwargs: Unpack[TransformersKwargs],
- ) -> tuple[torch.Tensor] | TokenClassifierOutput:
- r"""
- labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
- Labels for computing the token classification loss. Indices should be in `[0, ..., config.num_labels - 1]`.
- """
- discriminator_hidden_states = self.electra(
- input_ids,
- attention_mask=attention_mask,
- token_type_ids=token_type_ids,
- position_ids=position_ids,
- inputs_embeds=inputs_embeds,
- return_dict=True,
- **kwargs,
- )
- discriminator_sequence_output = discriminator_hidden_states[0]
- discriminator_sequence_output = self.dropout(discriminator_sequence_output)
- logits = self.classifier(discriminator_sequence_output)
- loss = None
- if labels is not None:
- loss_fct = CrossEntropyLoss()
- loss = loss_fct(logits.view(-1, self.num_labels), labels.view(-1))
- return TokenClassifierOutput(
- loss=loss,
- logits=logits,
- hidden_states=discriminator_hidden_states.hidden_states,
- attentions=discriminator_hidden_states.attentions,
- )
- @auto_docstring
- class ElectraForQuestionAnswering(ElectraPreTrainedModel):
- config_class = ElectraConfig
- base_model_prefix = "electra"
- def __init__(self, config):
- super().__init__(config)
- self.num_labels = config.num_labels
- self.electra = ElectraModel(config)
- self.qa_outputs = nn.Linear(config.hidden_size, config.num_labels)
- # Initialize weights and apply final processing
- self.post_init()
- @can_return_tuple
- @auto_docstring
- def forward(
- self,
- input_ids: torch.Tensor | None = None,
- attention_mask: torch.Tensor | None = None,
- token_type_ids: torch.Tensor | None = None,
- position_ids: torch.Tensor | None = None,
- inputs_embeds: torch.Tensor | None = None,
- start_positions: torch.Tensor | None = None,
- end_positions: torch.Tensor | None = None,
- **kwargs: Unpack[TransformersKwargs],
- ) -> tuple[torch.Tensor] | QuestionAnsweringModelOutput:
- discriminator_hidden_states = self.electra(
- input_ids,
- attention_mask=attention_mask,
- token_type_ids=token_type_ids,
- position_ids=position_ids,
- inputs_embeds=inputs_embeds,
- return_dict=True,
- **kwargs,
- )
- sequence_output = discriminator_hidden_states[0]
- logits = self.qa_outputs(sequence_output)
- start_logits, end_logits = logits.split(1, dim=-1)
- start_logits = start_logits.squeeze(-1).contiguous()
- end_logits = end_logits.squeeze(-1).contiguous()
- total_loss = None
- if start_positions is not None and end_positions is not None:
- # If we are on multi-GPU, split add a dimension
- if len(start_positions.size()) > 1:
- start_positions = start_positions.squeeze(-1)
- if len(end_positions.size()) > 1:
- end_positions = end_positions.squeeze(-1)
- # sometimes the start/end positions are outside our model inputs, we ignore these terms
- ignored_index = start_logits.size(1)
- start_positions = start_positions.clamp(0, ignored_index)
- end_positions = end_positions.clamp(0, ignored_index)
- loss_fct = CrossEntropyLoss(ignore_index=ignored_index)
- start_loss = loss_fct(start_logits, start_positions)
- end_loss = loss_fct(end_logits, end_positions)
- total_loss = (start_loss + end_loss) / 2
- return QuestionAnsweringModelOutput(
- loss=total_loss,
- start_logits=start_logits,
- end_logits=end_logits,
- hidden_states=discriminator_hidden_states.hidden_states,
- attentions=discriminator_hidden_states.attentions,
- )
- @auto_docstring
- class ElectraForMultipleChoice(ElectraPreTrainedModel):
- def __init__(self, config):
- super().__init__(config)
- self.electra = ElectraModel(config)
- self.sequence_summary = ElectraSequenceSummary(config)
- self.classifier = nn.Linear(config.hidden_size, 1)
- # Initialize weights and apply final processing
- self.post_init()
- @can_return_tuple
- @auto_docstring
- def forward(
- self,
- input_ids: torch.Tensor | None = None,
- attention_mask: torch.Tensor | None = None,
- token_type_ids: torch.Tensor | None = None,
- position_ids: torch.Tensor | None = None,
- inputs_embeds: torch.Tensor | None = None,
- labels: torch.Tensor | None = None,
- **kwargs: Unpack[TransformersKwargs],
- ) -> tuple[torch.Tensor] | MultipleChoiceModelOutput:
- r"""
- input_ids (`torch.LongTensor` of shape `(batch_size, num_choices, sequence_length)`):
- Indices of input sequence tokens in the vocabulary.
- Indices can be obtained using [`AutoTokenizer`]. See [`PreTrainedTokenizer.encode`] and
- [`PreTrainedTokenizer.__call__`] for details.
- [What are input IDs?](../glossary#input-ids)
- token_type_ids (`torch.LongTensor` of shape `(batch_size, num_choices, sequence_length)`, *optional*):
- Segment token indices to indicate first and second portions of the inputs. Indices are selected in `[0,
- 1]`:
- - 0 corresponds to a *sentence A* token,
- - 1 corresponds to a *sentence B* token.
- [What are token type IDs?](../glossary#token-type-ids)
- position_ids (`torch.LongTensor` of shape `(batch_size, num_choices, sequence_length)`, *optional*):
- Indices of positions of each input sequence tokens in the position embeddings. Selected in the range `[0,
- config.max_position_embeddings - 1]`.
- [What are position IDs?](../glossary#position-ids)
- inputs_embeds (`torch.FloatTensor` of shape `(batch_size, num_choices, sequence_length, hidden_size)`, *optional*):
- Optionally, instead of passing `input_ids` you can choose to directly pass an embedded representation. This
- is useful if you want more control over how to convert `input_ids` indices into associated vectors than the
- model's internal embedding lookup matrix.
- labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
- Labels for computing the multiple choice classification loss. Indices should be in `[0, ...,
- num_choices-1]` where `num_choices` is the size of the second dimension of the input tensors. (See
- `input_ids` above)
- """
- num_choices = input_ids.shape[1] if input_ids is not None else inputs_embeds.shape[1]
- input_ids = input_ids.view(-1, input_ids.size(-1)) if input_ids is not None else None
- attention_mask = attention_mask.view(-1, attention_mask.size(-1)) if attention_mask is not None else None
- token_type_ids = token_type_ids.view(-1, token_type_ids.size(-1)) if token_type_ids is not None else None
- position_ids = position_ids.view(-1, position_ids.size(-1)) if position_ids is not None else None
- inputs_embeds = (
- inputs_embeds.view(-1, inputs_embeds.size(-2), inputs_embeds.size(-1))
- if inputs_embeds is not None
- else None
- )
- discriminator_hidden_states = self.electra(
- input_ids,
- attention_mask=attention_mask,
- token_type_ids=token_type_ids,
- position_ids=position_ids,
- inputs_embeds=inputs_embeds,
- return_dict=True,
- **kwargs,
- )
- sequence_output = discriminator_hidden_states[0]
- pooled_output = self.sequence_summary(sequence_output)
- logits = self.classifier(pooled_output)
- reshaped_logits = logits.view(-1, num_choices)
- loss = None
- if labels is not None:
- loss_fct = CrossEntropyLoss()
- loss = loss_fct(reshaped_logits, labels)
- return MultipleChoiceModelOutput(
- loss=loss,
- logits=reshaped_logits,
- hidden_states=discriminator_hidden_states.hidden_states,
- attentions=discriminator_hidden_states.attentions,
- )
- @auto_docstring(
- custom_intro="""
- ELECTRA Model with a `language modeling` head on top for CLM fine-tuning.
- """
- )
- class ElectraForCausalLM(ElectraPreTrainedModel, GenerationMixin):
- _tied_weights_keys = {"generator_lm_head.weight": "electra.embeddings.word_embeddings.weight"}
- def __init__(self, config):
- super().__init__(config)
- if not config.is_decoder:
- logger.warning("If you want to use `ElectraForCausalLM` as a standalone, add `is_decoder=True.`")
- self.electra = ElectraModel(config)
- self.generator_predictions = ElectraGeneratorPredictions(config)
- self.generator_lm_head = nn.Linear(config.embedding_size, config.vocab_size)
- self.post_init()
- def get_output_embeddings(self):
- return self.generator_lm_head
- def set_output_embeddings(self, new_embeddings):
- self.generator_lm_head = new_embeddings
- @can_return_tuple
- @auto_docstring
- def forward(
- self,
- input_ids: torch.Tensor | None = None,
- attention_mask: torch.Tensor | None = None,
- token_type_ids: torch.Tensor | None = None,
- position_ids: torch.Tensor | None = None,
- inputs_embeds: torch.Tensor | None = None,
- encoder_hidden_states: torch.Tensor | None = None,
- encoder_attention_mask: torch.Tensor | None = None,
- labels: torch.Tensor | None = None,
- past_key_values: Cache | None = None,
- use_cache: bool | None = None,
- logits_to_keep: int | torch.Tensor = 0,
- **kwargs: Unpack[TransformersKwargs],
- ) -> tuple[torch.Tensor] | CausalLMOutputWithCrossAttentions:
- r"""
- labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
- Labels for computing the left-to-right language modeling loss (next word prediction). Indices should be in
- `[-100, 0, ..., config.vocab_size]` (see `input_ids` docstring) Tokens with indices set to `-100` are
- ignored (masked), the loss is only computed for the tokens with labels in `[0, ..., config.vocab_size]`
- Example:
- ```python
- >>> from transformers import AutoTokenizer, ElectraForCausalLM, ElectraConfig
- >>> import torch
- >>> tokenizer = AutoTokenizer.from_pretrained("google/electra-base-generator")
- >>> config = ElectraConfig.from_pretrained("google/electra-base-generator")
- >>> config.is_decoder = True
- >>> model = ElectraForCausalLM.from_pretrained("google/electra-base-generator", config=config)
- >>> inputs = tokenizer("Hello, my dog is cute", return_tensors="pt")
- >>> outputs = model(**inputs)
- >>> prediction_logits = outputs.logits
- ```"""
- if labels is not None:
- use_cache = False
- outputs: BaseModelOutputWithPastAndCrossAttentions = self.electra(
- input_ids,
- attention_mask=attention_mask,
- token_type_ids=token_type_ids,
- position_ids=position_ids,
- inputs_embeds=inputs_embeds,
- encoder_hidden_states=encoder_hidden_states,
- encoder_attention_mask=encoder_attention_mask,
- past_key_values=past_key_values,
- use_cache=use_cache,
- return_dict=True,
- **kwargs,
- )
- hidden_states = outputs.last_hidden_state
- # Only compute necessary logits, and do not upcast them to float if we are not computing the loss
- slice_indices = slice(-logits_to_keep, None) if isinstance(logits_to_keep, int) else logits_to_keep
- logits = self.generator_lm_head(self.generator_predictions(hidden_states[:, slice_indices, :]))
- loss = None
- if labels is not None:
- loss = self.loss_function(logits=logits, labels=labels, vocab_size=self.config.vocab_size, **kwargs)
- return CausalLMOutputWithCrossAttentions(
- loss=loss,
- logits=logits,
- past_key_values=outputs.past_key_values,
- hidden_states=outputs.hidden_states,
- attentions=outputs.attentions,
- cross_attentions=outputs.cross_attentions,
- )
- __all__ = [
- "ElectraForCausalLM",
- "ElectraForMaskedLM",
- "ElectraForMultipleChoice",
- "ElectraForPreTraining",
- "ElectraForQuestionAnswering",
- "ElectraForSequenceClassification",
- "ElectraForTokenClassification",
- "ElectraModel",
- "ElectraPreTrainedModel",
- ]
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