File size: 8,108 Bytes
64a20cd
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
from dataclasses import dataclass
from typing import Optional, List
from transformers import AutoModelForSeq2SeqLM, AutoTokenizer, GenerationConfig
import regex as re
import torch
import torch.nn.functional as F

PROGRAM_SPECIAL_TOKEN="<extra_id_124>"
UTTERANCES_SPECIAL_TOKEN="<extra_id_123>"
GT_PROGRAM_SPECIAL_TOKEN="<extra_id_122>"

def consistent(rx, spec):
    # spec is in the form of (string, '+'/'-') pairs
    for s, label in spec:
        if not label in ['+', '-']:
            return None
        try:
            if re.fullmatch(rx, s, timeout=1):
                if label == '-':
                    return False
            else:
                if label == '+':
                    return False
        except re.error:
            return None
        except TimeoutError:
            return None

    return True

def get_utterance_processing_functions(label_pos, idx, separator=' '):
    if label_pos == "suffix":
        if idx:
            def utterances_to_string(spec):
                return ''.join([f"<extra_id_{i}>{s}{label}" for i, (s, label) in enumerate(spec)])
        else:
            def utterances_to_string(spec):
                return separator.join([f"{s}{label}" for s, label in spec])
    else:
        if idx:
            def utterances_to_string(spec):
                return ''.join([f"<extra_id_{i}>{label}{s}" for i, (s, label) in enumerate(spec)])
        else:
            def utterances_to_string(spec):
                return separator.join([f"{label}{s}" for s, label in spec])
    
    if label_pos == "suffix":
        if idx:
            def string_to_utterances(string):
                string = re.sub(r'<extra_id_\d+>', ' ', string)
                return [(s[:-1], s[-1]) for s in string.split(' ') if len(s) > 0]
        else:
            def string_to_utterances(string):
                return [(s[:-1], s[-1]) for s in string.split(separator) if len(s) > 0]
    else:
        if idx:
            def string_to_utterances(string):
                string = re.sub(r'<extra_id_\d+>', '', string)
                return [(s[1:], s[0]) for s in string.split(separator) if len(s) > 0]
        else:
            def string_to_utterances(string):
                return [(s[1:], s[0]) for s in string.split(separator) if len(s) > 0]
    
    return utterances_to_string, string_to_utterances

def decode(c):
    if c < 3:
        return f"<{c}>"
    elif c < 258:
        return chr(c - 3)
    else:
        return f"<extra_id_{c - 259}>"
    
def byt5_decode_batch(outputs, skip_special_tokens=True, skip_position_token=False):
    skipped_tokens = outputs
    if skip_special_tokens:
        skipped_tokens = [
            [[t for t in x if t >= 3] for x in beam]
            for beam in skipped_tokens
            ]
    
    if skip_position_token:
        skipped_tokens = [
            [[t for t in x if t <= 258] for x in beam] 
            for beam in skipped_tokens
            ]

    return [
        [''.join([decode(t) for t in x]) for x in beam]
        for beam in skipped_tokens
    ]

class Agent:
    def __init__(self, 
                model_path: str,
                gen_config: dict, 
                device: str = "cuda", 
                ):
        self.device = device
        self.model = AutoModelForSeq2SeqLM.from_pretrained(model_path).to(device)
        self.tokenizer = AutoTokenizer.from_pretrained(model_path)
        self.gen_config = GenerationConfig(**gen_config)

@dataclass
class ListenerOutput:
    programs: List[List[str]]
    idx: Optional[List[List[int]]] = None
    decoded: Optional[List[List[str]]] = None
    decoded_scores: Optional[List[List[float]]] = None
    pruned: Optional[List[List[str]]] = None


class Listener(Agent):
    def __init__(self, 
        model_path, 
        gen_config,
        device="cuda",
        label_pos="suffix",
        idx: bool=True,
        program_special_token=PROGRAM_SPECIAL_TOKEN,
        utterances_special_token=UTTERANCES_SPECIAL_TOKEN
    ):
        super().__init__(
            model_path, 
            gen_config,
            device=device
        )
        self.label_pos = label_pos
        self.idx = idx
        self.program_special_token = program_special_token
        self.utterances_special_token = utterances_special_token
        self.utterances_to_string, self.string_to_utterances = (
            get_utterance_processing_functions(
                label_pos, idx, separator=utterances_special_token
                )
            )
    
    def synthesize(self, context, return_scores=False, enforce_consistency=True):
        # If context is a list of utterances, convert to string
        if isinstance(context[0], list):
            context_str = list(map(self.utterances_to_string, context))
        else:
            context_str = context

        context_tokens = self.tokenizer(
            [f"{self.utterances_special_token}{c}" if not c.startswith(self.utterances_special_token) else c 
            for c in context_str], 
            return_tensors="pt",
            padding=True
            ).to(self.device)
        
        decoder_inputs = self.tokenizer(
            [self.program_special_token for _ in context], return_tensors="pt",
            add_special_tokens=False
            ).to(self.device)

        outputs = self.model.generate(**context_tokens, 
                                      decoder_input_ids=decoder_inputs.input_ids,
                                      generation_config=self.gen_config, 
                                      return_dict_in_generate=True, 
                                      output_scores=True
                                      )

        decoded_batch = byt5_decode_batch(outputs.sequences.reshape((len(context), -1, outputs.sequences.shape[-1])).tolist(), skip_position_token=True, skip_special_tokens=True)

        consistent_programs = []
        idxs = []
        for decoded, ctx in zip(decoded_batch, context):
            cp = []
            idx = []
            for i, p in enumerate(decoded):
                if enforce_consistency:
                    if consistent(p, ctx):
                        cp.append(p)
                        idx.append(i)
                else:
                    cp.append(p)
                    idx.append(i)
            
            consistent_programs.append(cp)
            idxs.append(idx)
        
        logprobs = torch.stack(outputs.scores, dim=1).log_softmax(dim=-1)
        gen_probs = torch.gather(logprobs, 2, outputs.sequences[:, 1:, None]).squeeze(-1)
        gen_probs.masked_fill_(gen_probs.isinf(), 0)
        scores = gen_probs.sum(-1)
        n_decoded = scores.shape[0]
        n_seq = n_decoded // len(context)
        scores = scores.reshape((len(context), n_seq))
        scores_list = scores.tolist()

        if return_scores:
            return ListenerOutput(
                consistent_programs,
                idxs, 
                decoded_batch, 
                scores_list
                )
        else:
            return ListenerOutput(consistent_programs)

    
    def score_program(self, contexts, programs):
        if isinstance(contexts[0], list):
            context_str = list(map(self.utterances_to_string, contexts))
        else:
            context_str = contexts

        context_tokens = self.tokenizer(
            [f"{self.utterances_special_token}{c}" if not c.startswith(self.utterances_special_token) else c 
            for c in context_str], 
            return_tensors="pt",
            padding=True
            ).to(self.device)

        program_tokens = self.tokenizer([f"{self.program_special_token}{p}" for p in programs], return_tensors="pt").to(self.device)
        outputs = self.model(input_ids=context_tokens.input_ids, decoder_input_ids=program_tokens.input_ids, return_dict=True)
        
        logprobs = torch.gather(F.log_softmax(outputs.logits, dim=-1), 2, program_tokens.input_ids[:, 1:, None]).squeeze(-1)
        
        logprobs.masked_fill_(program_tokens.input_ids[:, 1:] == 0, 0)

        scores = logprobs.sum(-1)
        
        return scores.tolist()