import torch.nn as nn from transformers.models.gpt2.modeling_gpt2 import GPT2Attention, GPT2MLP from typing import Optional, Tuple, Union, List from transformers import GPT2LMHeadModel import torch from transformers.deepspeed import is_deepspeed_zero3_enabled from transformers.generation.logits_process import LogitsProcessorList from transformers.generation.stopping_criteria import StoppingCriteriaList from transformers.generation.utils import GreedySearchOutput, GreedySearchEncoderDecoderOutput, BeamSearchOutput, BeamSearchEncoderDecoderOutput from transformers.generation.beam_search import BeamScorer class _GPT2LMHeadModel(GPT2LMHeadModel): def _init_(self, config): super(GPT2LMHeadModel, self).init_(config) self.config = config def prepare_inputs_for_generation(self, input_ids, past_key_values=None, encoder_outputs=None, **kwargs): ''' This function is an edited version of the prepare_inputs_for_generation function from HuggingFace's transformers https://github.com/huggingface/transformers/blob/main/src/transformers/models/gpt2/modeling_gpt2.py ''' token_type_ids = kwargs.get("token_type_ids", None) # only last token for inputs_ids if past is defined in kwargs if past_key_values: input_ids = input_ids[:, -1].unsqueeze(-1) if token_type_ids is not None: token_type_ids = token_type_ids[:, -1].unsqueeze(-1) attention_mask = kwargs.get("attention_mask", None) position_ids = kwargs.get("position_ids", None) if self.config.prot2text_version=="1.1" or self.config.prot2text_version=="1.2": encoder_attention_mask = kwargs.get("encoder_attention_mask", None) elif self.config.prot2text_version=="1.0": encoder_attention_mask = None if attention_mask is not None and position_ids is None: position_ids = attention_mask.long().cumsum(-1) - 1 position_ids.masked_fill_(attention_mask == 0, 1) if past_key_values: position_ids = position_ids[:, -1].unsqueeze(-1) else: position_ids = None model_specific_kwargs = { "encoder_hidden_states": encoder_outputs['hidden_states'], } return { "input_ids": input_ids, "past_key_values": past_key_values, "use_cache": kwargs.get("use_cache"), "position_ids": position_ids, "attention_mask": attention_mask, "token_type_ids": token_type_ids, "encoder_attention_mask": encoder_attention_mask, **model_specific_kwargs } def greedy_search( self, input_ids: torch.LongTensor, logits_processor: Optional[LogitsProcessorList] = None, stopping_criteria: Optional[StoppingCriteriaList] = None, max_length: Optional[int] = None, pad_token_id: Optional[int] = None, eos_token_id: Optional[Union[int, List[int]]] = None, output_attentions: Optional[bool] = None, output_hidden_states: Optional[bool] = None, output_scores: Optional[bool] = None, return_dict_in_generate: Optional[bool] = None, synced_gpus: bool = False, streamer: Optional["BaseStreamer"] = None, **model_kwargs, ) -> Union[GreedySearchOutput, torch.LongTensor]: ''' This function is an edited version of the greedy_search function from HuggingFace's transformers https://github.com/huggingface/transformers/blob/main/src/transformers/generation/utils.py ''' # init values logits_processor = logits_processor if logits_processor is not None else LogitsProcessorList() stopping_criteria = stopping_criteria if stopping_criteria is not None else StoppingCriteriaList() if max_length is not None: warnings.warn( "`max_length` is deprecated in this function, use" " `stopping_criteria=StoppingCriteriaList([MaxLengthCriteria(max_length=max_length)])` instead.", UserWarning, ) stopping_criteria = validate_stopping_criteria(stopping_criteria, max_length) pad_token_id = pad_token_id if pad_token_id is not None else self.generation_config.pad_token_id eos_token_id = eos_token_id if eos_token_id is not None else self.generation_config.eos_token_id if isinstance(eos_token_id, int): eos_token_id = [eos_token_id] eos_token_id_tensor = torch.tensor(eos_token_id).to(input_ids.device) if eos_token_id is not None else None output_scores = output_scores if output_scores is not None else self.generation_config.output_scores output_attentions = ( output_attentions if output_attentions is not None else self.generation_config.output_attentions ) output_hidden_states = ( output_hidden_states if output_hidden_states is not None else self.generation_config.output_hidden_states ) return_dict_in_generate = ( return_dict_in_generate if return_dict_in_generate is not None else self.generation_config.return_dict_in_generate ) # init attention / hidden states / scores tuples scores = () if (return_dict_in_generate and output_scores) else None decoder_attentions = () if (return_dict_in_generate and output_attentions) else None cross_attentions = () if (return_dict_in_generate and output_attentions) else None decoder_hidden_states = () if (return_dict_in_generate and output_hidden_states) else None # if model is an encoder-decoder, retrieve encoder attention weights and hidden states if return_dict_in_generate and self.config.is_encoder_decoder: encoder_attentions = model_kwargs["encoder_outputs"].get("attentions") if output_attentions else None encoder_hidden_states = ( model_kwargs["encoder_outputs"].get("hidden_states") if output_hidden_states else None ) # keep track of which sequences are already finished unfinished_sequences = torch.ones(input_ids.shape[0], dtype=torch.long, device=input_ids.device) this_peer_finished = False # used by synced_gpus only while True: if synced_gpus: # Under synced_gpus the `forward` call must continue until all gpus complete their sequence. # The following logic allows an early break if all peers finished generating their sequence this_peer_finished_flag = torch.tensor(0.0 if this_peer_finished else 1.0).to(input_ids.device) # send 0.0 if we finished, 1.0 otherwise dist.all_reduce(this_peer_finished_flag, op=dist.ReduceOp.SUM) # did all peers finish? the reduced sum will be 0.0 then if this_peer_finished_flag.item() == 0.0: break # prepare model inputs model_inputs = self.prepare_inputs_for_generation(input_ids, **model_kwargs) # forward pass to get next token outputs = self( **model_inputs, return_dict=True, output_attentions=output_attentions, output_hidden_states=output_hidden_states, ) if synced_gpus and this_peer_finished: continue # don't waste resources running the code we don't need next_token_logits = outputs.logits[:, -1, :] # pre-process distribution next_tokens_scores = logits_processor(input_ids, next_token_logits) # Store scores, attentions and hidden_states when required if return_dict_in_generate: if output_scores: scores += (next_tokens_scores,) if output_attentions: decoder_attentions += ( (outputs.decoder_attentions,) if not self.config.is_encoder_decoder else (outputs.attentions,) ) if self.config.is_encoder_decoder: cross_attentions += (outputs.cross_attentions,) if output_hidden_states: decoder_hidden_states += ( (outputs.decoder_hidden_states,) if self.config.is_encoder_decoder else (outputs.hidden_states,) ) # argmax next_tokens = torch.argmax(next_tokens_scores, dim=-1) # finished sentences should have their next token be a padding token if eos_token_id is not None: if pad_token_id is None: raise ValueError("If `eos_token_id` is defined, make sure that `pad_token_id` is defined.") next_tokens = next_tokens * unfinished_sequences + pad_token_id * (1 - unfinished_sequences) # update generated ids, model inputs, and length for next step input_ids = torch.cat([input_ids, next_tokens[:, None]], dim=-1) if streamer is not None: streamer.put(next_tokens.cpu()) model_kwargs = self._update_model_kwargs_for_generation( outputs, model_kwargs, is_encoder_decoder=self.config.is_encoder_decoder ) # if eos_token was found in one sentence, set sentence to finished if eos_token_id_tensor is not None: unfinished_sequences = unfinished_sequences.mul( next_tokens.tile(eos_token_id_tensor.shape[0], 1).ne(eos_token_id_tensor.unsqueeze(1)).prod(dim=0) ) # stop when each sentence is finished if unfinished_sequences.max() == 0: this_peer_finished = True # stop if we exceed the maximum length try: if stopping_criteria(input_ids, scores): this_peer_finished = True except: if all(stopping_criteria(input_ids, scores)): this_peer_finished = True if this_peer_finished and not synced_gpus: break if streamer is not None: streamer.end() if return_dict_in_generate: if self.config.is_encoder_decoder: return GreedySearchEncoderDecoderOutput( sequences=input_ids, scores=scores, encoder_attentions=encoder_attentions, encoder_hidden_states=encoder_hidden_states, decoder_attentions=decoder_attentions, cross_attentions=cross_attentions, decoder_hidden_states=decoder_hidden_states, ) else: return GreedySearchDecoderOnlyOutput( sequences=input_ids, scores=scores, attentions=decoder_attentions, hidden_states=decoder_hidden_states, ) else: return input_ids def _greedy_search( self, input_ids: torch.LongTensor, logits_processor: Optional[LogitsProcessorList] = None, stopping_criteria: Optional[StoppingCriteriaList] = None, max_length: Optional[int] = None, pad_token_id: Optional[int] = None, eos_token_id: Optional[Union[int, List[int]]] = None, output_attentions: Optional[bool] = None, output_hidden_states: Optional[bool] = None, output_scores: Optional[bool] = None, return_dict_in_generate: Optional[bool] = None, synced_gpus: bool = False, streamer: Optional["BaseStreamer"] = None, **model_kwargs, ) -> Union[GreedySearchOutput, torch.LongTensor]: return self.greedy_search( input_ids, logits_processor, stopping_criteria, max_length, pad_token_id, eos_token_id, output_attentions, output_hidden_states, output_scores, return_dict_in_generate, synced_gpus, streamer, **model_kwargs, ) def _beam_search( self, input_ids: torch.LongTensor, beam_scorer: BeamScorer, logits_processor: Optional[LogitsProcessorList] = None, stopping_criteria: Optional[StoppingCriteriaList] = None, max_length: Optional[int] = None, pad_token_id: Optional[int] = None, eos_token_id: Optional[Union[int, List[int]]] = None, output_attentions: Optional[bool] = None, output_hidden_states: Optional[bool] = None, output_scores: Optional[bool] = None, return_dict_in_generate: Optional[bool] = None, synced_gpus: bool = False, **model_kwargs, ) -> Union[BeamSearchOutput, torch.LongTensor]: return self.beam_search( input_ids, beam_scorer, logits_processor, stopping_criteria, max_length, pad_token_id, eos_token_id, output_attentions, output_hidden_states, output_scores, return_dict_in_generate, synced_gpus, **model_kwargs, ) def beam_search( self, input_ids: torch.LongTensor, beam_scorer: BeamScorer, logits_processor: Optional[LogitsProcessorList] = None, stopping_criteria: Optional[StoppingCriteriaList] = None, max_length: Optional[int] = None, pad_token_id: Optional[int] = None, eos_token_id: Optional[Union[int, List[int]]] = None, output_attentions: Optional[bool] = None, output_hidden_states: Optional[bool] = None, output_scores: Optional[bool] = None, return_dict_in_generate: Optional[bool] = None, synced_gpus: bool = False, **model_kwargs, ) -> Union[BeamSearchOutput, torch.LongTensor]: ''' This function is an edited version of the beam_search function from HuggingFace's transformers https://github.com/huggingface/transformers/blob/main/src/transformers/generation/utils.py ''' # init values logits_processor = logits_processor if logits_processor is not None else LogitsProcessorList() stopping_criteria = stopping_criteria if stopping_criteria is not None else StoppingCriteriaList() if max_length is not None: warnings.warn( "`max_length` is deprecated in this function, use" " `stopping_criteria=StoppingCriteriaList(MaxLengthCriteria(max_length=max_length))` instead.", UserWarning, ) stopping_criteria = validate_stopping_criteria(stopping_criteria, max_length) if len(stopping_criteria) == 0: warnings.warn("You don't have defined any stopping_criteria, this will likely loop forever", UserWarning) pad_token_id = pad_token_id if pad_token_id is not None else self.generation_config.pad_token_id eos_token_id = eos_token_id if eos_token_id is not None else self.generation_config.eos_token_id if isinstance(eos_token_id, int): eos_token_id = [eos_token_id] output_scores = output_scores if output_scores is not None else self.generation_config.output_scores output_attentions = ( output_attentions if output_attentions is not None else self.generation_config.output_attentions ) output_hidden_states = ( output_hidden_states if output_hidden_states is not None else self.generation_config.output_hidden_states ) return_dict_in_generate = ( return_dict_in_generate if return_dict_in_generate is not None else self.generation_config.return_dict_in_generate ) batch_size = len(beam_scorer._beam_hyps) num_beams = beam_scorer.num_beams batch_beam_size, cur_len = input_ids.shape if num_beams * batch_size != batch_beam_size: raise ValueError( f"Batch dimension of `input_ids` should be {num_beams * batch_size}, but is {batch_beam_size}." ) # init attention / hidden states / scores tuples scores = () if (return_dict_in_generate and output_scores) else None beam_indices = ( tuple(() for _ in range(batch_beam_size)) if (return_dict_in_generate and output_scores) else None ) decoder_attentions = () if (return_dict_in_generate and output_attentions) else None cross_attentions = () if (return_dict_in_generate and output_attentions) else None decoder_hidden_states = () if (return_dict_in_generate and output_hidden_states) else None # if model is an encoder-decoder, retrieve encoder attention weights and hidden states if return_dict_in_generate and self.config.is_encoder_decoder: encoder_attentions = model_kwargs["encoder_outputs"].get("attentions") if output_attentions else None encoder_hidden_states = ( model_kwargs["encoder_outputs"].get("hidden_states") if output_hidden_states else None ) # initialise score of first beam with 0 and the rest with -1e9. This makes sure that only tokens # of the first beam are considered to avoid sampling the exact same tokens across all beams. beam_scores = torch.zeros((batch_size, num_beams), dtype=torch.float, device=input_ids.device) beam_scores[:, 1:] = -1e9 beam_scores = beam_scores.view((batch_size * num_beams,)) this_peer_finished = False # used by synced_gpus only while True: if synced_gpus: # Under synced_gpus the `forward` call must continue until all gpus complete their sequence. # The following logic allows an early break if all peers finished generating their sequence this_peer_finished_flag = torch.tensor(0.0 if this_peer_finished else 1.0).to(input_ids.device) # send 0.0 if we finished, 1.0 otherwise dist.all_reduce(this_peer_finished_flag, op=dist.ReduceOp.SUM) # did all peers finish? the reduced sum will be 0.0 then if this_peer_finished_flag.item() == 0.0: break model_inputs = self.prepare_inputs_for_generation(input_ids, **model_kwargs) outputs = self( **model_inputs, return_dict=True, output_attentions=output_attentions, output_hidden_states=output_hidden_states, ) if synced_gpus and this_peer_finished: cur_len = cur_len + 1 continue # don't waste resources running the code we don't need next_token_logits = outputs.logits[:, -1, :] # hack: adjust tokens for Marian. For Marian we have to make sure that the `pad_token_id` # cannot be generated both before and after the `nn.functional.log_softmax` operation. # next_token_logits = self.adjust_logits_during_generation(next_token_logits, cur_len=cur_len) next_token_scores = nn.functional.log_softmax( next_token_logits, dim=-1 ) # (batch_size * num_beams, vocab_size) next_token_scores_processed = logits_processor(input_ids, next_token_scores) # next_token_scores = next_token_scores_processed + beam_scores[:, None].expand_as(next_token_scores) next_token_scores = next_token_scores_processed + beam_scores[:, None].expand_as( next_token_scores_processed ) # Store scores, attentions and hidden_states when required if return_dict_in_generate: if output_scores: scores += (next_token_scores_processed,) if output_attentions: decoder_attentions += ( (outputs.decoder_attentions,) if not self.config.is_encoder_decoder else (outputs.attentions,) ) if self.config.is_encoder_decoder: cross_attentions += (outputs.cross_attentions,) if output_hidden_states: decoder_hidden_states += ( (outputs.decoder_hidden_states,) if self.config.is_encoder_decoder else (outputs.hidden_states,) ) # reshape for beam search vocab_size = next_token_scores.shape[-1] next_token_scores = next_token_scores.view(batch_size, num_beams * vocab_size) # Sample 2 next tokens for each beam (so we have some spare tokens and match output of beam search) next_token_scores, next_tokens = torch.topk( next_token_scores, 2 * num_beams, dim=1, largest=True, sorted=True ) next_indices = torch.div(next_tokens, vocab_size, rounding_mode="floor") next_tokens = next_tokens % vocab_size # stateless beam_outputs = beam_scorer.process( input_ids, next_token_scores, next_tokens, next_indices, pad_token_id=pad_token_id, eos_token_id=eos_token_id, beam_indices=beam_indices, ) beam_scores = beam_outputs["next_beam_scores"] beam_next_tokens = beam_outputs["next_beam_tokens"] beam_idx = beam_outputs["next_beam_indices"] input_ids = torch.cat([input_ids[beam_idx, :], beam_next_tokens.unsqueeze(-1)], dim=-1) model_kwargs = self._update_model_kwargs_for_generation( outputs, model_kwargs, is_encoder_decoder=self.config.is_encoder_decoder ) if model_kwargs["past_key_values"] is not None: model_kwargs["past_key_values"] = self._reorder_cache(model_kwargs["past_key_values"], beam_idx) if return_dict_in_generate and output_scores: beam_indices = tuple((beam_indices[beam_idx[i]] + (beam_idx[i],) for i in range(len(beam_indices)))) # increase cur_len cur_len = cur_len + 1 try: if beam_scorer.is_done or stopping_criteria(input_ids, scores): if not synced_gpus: break else: this_peer_finished = True except: if beam_scorer.is_done or all(stopping_criteria(input_ids, scores)): if not synced_gpus: break else: this_peer_finished = True sequence_outputs = beam_scorer.finalize( input_ids, beam_scores, next_tokens, next_indices, pad_token_id=pad_token_id, eos_token_id=eos_token_id, max_length=stopping_criteria.max_length, beam_indices=beam_indices, ) if return_dict_in_generate: if not output_scores: sequence_outputs["sequence_scores"] = None if self.config.is_encoder_decoder: return BeamSearchEncoderDecoderOutput( sequences=sequence_outputs["sequences"], sequences_scores=sequence_outputs["sequence_scores"], scores=scores, beam_indices=sequence_outputs["beam_indices"], encoder_attentions=encoder_attentions, encoder_hidden_states=encoder_hidden_states, decoder_attentions=decoder_attentions, cross_attentions=cross_attentions, decoder_hidden_states=decoder_hidden_states, ) else: return BeamSearchDecoderOnlyOutput( sequences=sequence_outputs["sequences"], sequences_scores=sequence_outputs["sequence_scores"], scores=scores, beam_indices=sequence_outputs["beam_indices"], attentions=decoder_attentions, hidden_states=decoder_hidden_states, ) else: return sequence_outputs["sequences"] class CABlock(nn.Module): ''' This function is an edited version of the gpt2 decoder block function from HuggingFace's transformers https://github.com/huggingface/transformers/blob/main/src/transformers/models/gpt2/modeling_gpt2.py ''' def __init__(self, config, layer_idx=None): super().__init__() hidden_size = config.hidden_size inner_dim = config.n_inner if config.n_inner is not None else 4 * hidden_size self.ln_2 = nn.LayerNorm(hidden_size, eps=config.layer_norm_epsilon) self.crossattention = GPT2Attention(config, is_cross_attention=True, layer_idx=layer_idx) self.ln_cross_attn = nn.LayerNorm(hidden_size, eps=config.layer_norm_epsilon) self.mlp = GPT2MLP(inner_dim, config) def forward( self, hidden_states: Optional[Tuple[torch.FloatTensor]], layer_past: Optional[Tuple[torch.Tensor]] = None, attention_mask: Optional[torch.FloatTensor] = None, head_mask: Optional[torch.FloatTensor] = None, encoder_hidden_states: Optional[torch.Tensor] = None, encoder_attention_mask: Optional[torch.FloatTensor] = None, use_cache: Optional[bool] = False, output_attentions: Optional[bool] = False, ) -> Union[Tuple[torch.Tensor], Optional[Tuple[torch.Tensor, Tuple[torch.FloatTensor, ...]]]]: residual = hidden_states hidden_states = self.ln_cross_attn(hidden_states) cross_attn_outputs = self.crossattention( hidden_states, attention_mask=attention_mask, head_mask=head_mask, encoder_hidden_states=encoder_hidden_states, encoder_attention_mask=encoder_attention_mask, output_attentions=output_attentions, ) attn_output = cross_attn_outputs[0] # residual connection hidden_states = residual + attn_output residual = hidden_states hidden_states = self.ln_2(hidden_states) feed_forward_hidden_states = self.mlp(hidden_states) # residual connection hidden_states = residual + feed_forward_hidden_states return (hidden_states,)