File size: 11,372 Bytes
62f1812
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ee8156c
62f1812
 
 
 
 
 
 
 
 
 
 
 
 
ee8156c
 
 
 
 
62f1812
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ee8156c
62f1812
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
import warnings
from typing import Any, Dict, List, Optional, Union

import torch

from transformers import GenerationMixin, LogitsProcessorList, StoppingCriteriaList
from transformers.generation import validate_stopping_criteria, EosTokenCriteria
from transformers.generation.utils import GenerateNonBeamOutput, GenerateEncoderDecoderOutput, GenerateDecoderOnlyOutput
from transformers.utils import ModelOutput


class TSGenerationMixin(GenerationMixin):

    def _greedy_search(
            self,
            input_ids: torch.Tensor,
            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,
            output_logits: Optional[bool] = None,
            return_dict_in_generate: Optional[bool] = None,
            synced_gpus: bool = False,
            streamer: Optional["BaseStreamer"] = None,
            **model_kwargs,
    ) -> Union[GenerateNonBeamOutput, torch.Tensor]:
        if len(input_ids.shape) == 2:
            batch_size, cur_len = input_ids.shape
        else:
            raise ValueError('Input shape must be: [batch_size, seq_len]')
        # 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
        if eos_token_id is not None:
            stopping_criteria.append(EosTokenCriteria(eos_token_id=eos_token_id))
        else:
            # remove when the method is totally private
            # need to get `eos_token_id` and add stopping criteria, so that generation does not go forever
            eos_token_id = [
                criteria.eos_token_id.tolist() for criteria in stopping_criteria if hasattr(criteria, "eos_token_id")
            ]
            eos_token_id = eos_token_id[0] if eos_token_id else None
            if eos_token_id is None and self.generation_config.eos_token_id is not None:
                eos_token_id = self.generation_config.eos_token_id
                stopping_criteria.append(EosTokenCriteria(eos_token_id=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
        )

        # init attention / hidden states / scores tuples
        raw_logits = () if (return_dict_in_generate and output_logits) else None
        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
        if "inputs_embeds" in model_kwargs:
            cur_len = model_kwargs["inputs_embeds"].shape[1]
        this_peer_finished = False
        unfinished_sequences = torch.ones(batch_size, dtype=torch.long, device=input_ids.device)
        model_kwargs["cache_position"] = torch.arange(cur_len, device=input_ids.device)

        max_length = stopping_criteria.max_length
        while self._has_unfinished_sequences(this_peer_finished, synced_gpus, device=input_ids.device):
            # prepare model inputs
            model_inputs = self.prepare_inputs_for_generation(input_ids, **model_kwargs)

            input_length = input_ids.shape[1]

            # forward pass to get next token
            outputs = self(
                **model_inputs,
                return_dict=True,
                output_attentions=output_attentions,
                output_hidden_states=output_hidden_states,
                max_horizon_length=max_length - input_length,
            )

            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_logits:
                    raw_logits += (next_token_logits,)
                if output_attentions:
                    decoder_attentions += (
                        (outputs.decoder_attentions,) if 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)
            next_tokens = next_tokens_scores

            # 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
            next_tokens = next_tokens.reshape(batch_size, -1, self.config.input_size)
            horizon_length = next_tokens.shape[1]

            input_ids = torch.cat([input_ids, next_tokens], dim=-2)
            if streamer is not None:
                streamer.put(next_tokens.cpu())
            model_kwargs = self._update_model_kwargs_for_generation(
                outputs,
                model_kwargs,
                horizon_length=horizon_length,
                is_encoder_decoder=self.config.is_encoder_decoder,
            )

            unfinished_sequences = unfinished_sequences & ~stopping_criteria(input_ids[..., 0], scores)
            this_peer_finished = unfinished_sequences.max() == 0

        if input_ids.shape[1] > max_length:
            input_ids = input_ids[:, :max_length]

        if streamer is not None:
            streamer.end()

        if return_dict_in_generate:
            if self.config.is_encoder_decoder:
                return GenerateEncoderDecoderOutput(
                    sequences=input_ids,
                    scores=scores,
                    logits=raw_logits,
                    encoder_attentions=encoder_attentions,
                    encoder_hidden_states=encoder_hidden_states,
                    decoder_attentions=decoder_attentions,
                    cross_attentions=cross_attentions,
                    decoder_hidden_states=decoder_hidden_states,
                    past_key_values=model_kwargs.get("past_key_values"),
                )
            else:
                return GenerateDecoderOnlyOutput(
                    sequences=input_ids,
                    scores=scores,
                    logits=raw_logits,
                    attentions=decoder_attentions,
                    hidden_states=decoder_hidden_states,
                    past_key_values=model_kwargs.get("past_key_values"),
                )
        else:
            return input_ids.squeeze(dim=-1)

    def _update_model_kwargs_for_generation(
            self,
            outputs: ModelOutput,
            model_kwargs: Dict[str, Any],
            horizon_length: int = 1,
            is_encoder_decoder: bool = False,
            standardize_cache_format: bool = False,
    ) -> Dict[str, Any]:
        # update past_key_values
        model_kwargs["past_key_values"] = self._extract_past_from_model_output(
            outputs, standardize_cache_format=standardize_cache_format
        )
        if getattr(outputs, "state", None) is not None:
            model_kwargs["state"] = outputs.state

        # update token_type_ids with last value
        if "token_type_ids" in model_kwargs:
            token_type_ids = model_kwargs["token_type_ids"]
            model_kwargs["token_type_ids"] = torch.cat([token_type_ids, token_type_ids[:, -1].unsqueeze(-1)], dim=-1)

        if not is_encoder_decoder:
            # update attention mask
            if "attention_mask" in model_kwargs:
                attention_mask = model_kwargs["attention_mask"]
                model_kwargs["attention_mask"] = torch.cat(
                    [attention_mask, attention_mask.new_ones((attention_mask.shape[0], horizon_length))], dim=-1
                )
        else:
            # update decoder attention mask
            if "decoder_attention_mask" in model_kwargs:
                decoder_attention_mask = model_kwargs["decoder_attention_mask"]
                model_kwargs["decoder_attention_mask"] = torch.cat(
                    [decoder_attention_mask, decoder_attention_mask.new_ones((decoder_attention_mask.shape[0], 1))],
                    dim=-1,
                )

        if "cache_position" in model_kwargs and model_kwargs["cache_position"] is not None:
            # model_kwargs["cache_position"] = model_kwargs["cache_position"][-1:] + horizon_length
            model_kwargs["cache_position"] = model_kwargs["cache_position"][-1:] + 1

        return model_kwargs