File size: 9,873 Bytes
b87a3ce
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
import tiktoken
from typing import TYPE_CHECKING, Any, Dict, Generator, List, Literal, Union
from itertools import chain

from llmtuner.extras.constants import IGNORE_INDEX
from llmtuner.extras.template import get_template_and_fix_tokenizer

if TYPE_CHECKING:
    from datasets import Dataset, IterableDataset
    from transformers import Seq2SeqTrainingArguments
    from transformers.tokenization_utils import PreTrainedTokenizer
    from llmtuner.hparams import DataArguments


def preprocess_dataset(
    dataset: Union["Dataset", "IterableDataset"],
    tokenizer: "PreTrainedTokenizer",
    data_args: "DataArguments",
    training_args: "Seq2SeqTrainingArguments",
    stage: Literal["pt", "sft", "rm", "ppo"]
) -> Union["Dataset", "IterableDataset"]:
    column_names = list(next(iter(dataset)).keys())
    template = get_template_and_fix_tokenizer(data_args.template, tokenizer)

    def construct_example(examples: Dict[str, List[Any]]) -> Generator[Any, None, None]:
        for i in range(len(examples["prompt"])):
            query, response = examples["prompt"][i], examples["response"][i]
            query = query + "\n" + examples["query"][i] if "query" in examples and examples["query"][i] else query
            history = examples["history"][i] if "history" in examples else None
            system = examples["system"][i] if "system" in examples else None
            yield query, response, history, system

    def preprocess_pretrain_dataset(examples: Dict[str, List[Any]]) -> Dict[str, Any]:
        # build grouped texts with format `X1 X2 X3 ...`
        if isinstance(getattr(tokenizer, "tokenizer", None), tiktoken.Encoding):
            kwargs = dict(allowed_special="all") # for tiktoken tokenizer (Qwen)
        else:
            kwargs = dict(add_special_tokens=True)

        if hasattr(tokenizer, "add_bos_token") and hasattr(tokenizer, "add_eos_token"):
            setattr(tokenizer, "add_bos_token", True) # for LLaMA tokenizer
            setattr(tokenizer, "add_eos_token", True)

        tokenized_examples = tokenizer(examples["prompt"], **kwargs)
        concatenated_examples = {k: list(chain(*tokenized_examples[k])) for k in tokenized_examples.keys()}
        total_length = len(concatenated_examples[list(concatenated_examples.keys())[0]])
        block_size = data_args.cutoff_len
        # we drop the small remainder, and if the total_length < block_size, we exclude this batch
        total_length = (total_length // block_size) * block_size
        # split by chunks of cutoff_len
        result = {
            k: [t[i: i + block_size] for i in range(0, total_length, block_size)]
            for k, t in concatenated_examples.items()
        }
        return result

    def preprocess_supervised_dataset(examples: Dict[str, List[Any]]) -> Dict[str, Any]:
        # build inputs with format `<bos> X Y <eos>` and labels with format `<ignore> ... <ignore> Y <eos>`
        # for multiturn examples, we only mask the prompt part in each prompt-response pair.
        model_inputs = {"input_ids": [], "attention_mask": [], "labels": []}

        for query, response, history, system in construct_example(examples):
            input_ids, labels = [], []

            for turn_idx, (source_ids, target_ids) in enumerate(template.encode_multiturn(
                tokenizer, query, response, history, system
            )):
                total_len = len(source_ids) + len(target_ids)
                max_source_len = int(data_args.cutoff_len * (len(source_ids) / total_len))
                max_target_len = int(data_args.cutoff_len * (len(target_ids) / total_len))

                if len(source_ids) > max_source_len:
                    source_ids = source_ids[:max_source_len]
                if len(target_ids) > max_target_len:
                    target_ids = target_ids[:max_target_len]

                if turn_idx != 0 and template.efficient_eos:
                    source_mask = [tokenizer.eos_token_id] + [IGNORE_INDEX] * (len(source_ids) - 1)
                else:
                    source_mask = [IGNORE_INDEX] * len(source_ids)

                input_ids += source_ids + target_ids
                labels += source_mask + target_ids

            if template.efficient_eos:
                input_ids += [tokenizer.eos_token_id]
                labels += [tokenizer.eos_token_id]

            if len(input_ids) > data_args.cutoff_len:
                input_ids = input_ids[:data_args.cutoff_len]
                labels = labels[:data_args.cutoff_len]

            model_inputs["input_ids"].append(input_ids)
            model_inputs["attention_mask"].append([1] * len(input_ids))
            model_inputs["labels"].append(labels)

        return model_inputs

    def preprocess_unsupervised_dataset(examples: Dict[str, List[Any]]) -> Dict[str, Any]:
        # build inputs with format `<bos> X` and labels with format `Y <eos>`
        model_inputs = {"input_ids": [], "attention_mask": [], "labels": []}

        for query, response, history, system in construct_example(examples):
            input_ids, labels = template.encode_oneturn(tokenizer, query, response, history, system)

            if template.efficient_eos:
                labels += [tokenizer.eos_token_id]

            if len(input_ids) > data_args.cutoff_len:
                input_ids = input_ids[:data_args.cutoff_len]
            if len(labels) > data_args.cutoff_len:
                labels = labels[:data_args.cutoff_len]

            model_inputs["input_ids"].append(input_ids)
            model_inputs["attention_mask"].append([1] * len(input_ids))
            model_inputs["labels"].append(labels)

        return model_inputs

    def preprocess_pairwise_dataset(examples):
        # build input pairs with format `<bos> X`, `Y1 <eos>` and `Y2 <eos>`
        model_inputs = {"prompt_ids": [], "chosen_ids": [], "rejected_ids": []}
        for query, response, history, system in construct_example(examples):
            prompt_ids, chosen_ids = template.encode_oneturn(tokenizer, query, response[0], history, system)
            _, rejected_ids = template.encode_oneturn(tokenizer, query, response[1], history, system)

            if template.efficient_eos:
                chosen_ids += [tokenizer.eos_token_id]
                rejected_ids += [tokenizer.eos_token_id]

            total_len = len(prompt_ids) + max(len(chosen_ids), len(rejected_ids))
            max_source_len = int(data_args.cutoff_len * (len(prompt_ids) / total_len))
            max_target_len = int(data_args.cutoff_len * (max(len(chosen_ids), len(rejected_ids)) / total_len))

            if len(prompt_ids) > max_source_len:
                prompt_ids = prompt_ids[:max_source_len]
            if len(chosen_ids) > max_target_len:
                chosen_ids = chosen_ids[:max_target_len]
            if len(rejected_ids) > max_target_len:
                rejected_ids = rejected_ids[:max_target_len]

            model_inputs["prompt_ids"].append(prompt_ids)
            model_inputs["chosen_ids"].append(chosen_ids)
            model_inputs["rejected_ids"].append(rejected_ids)
        return model_inputs

    def print_supervised_dataset_example(example):
        print("input_ids:\n{}".format(example["input_ids"]))
        print("inputs:\n{}".format(tokenizer.decode(example["input_ids"], skip_special_tokens=False)))
        print("label_ids:\n{}".format(example["labels"]))
        print("labels:\n{}".format(
            tokenizer.decode(list(filter(lambda x: x != IGNORE_INDEX, example["labels"])), skip_special_tokens=False)
        ))

    def print_pairwise_dataset_example(example):
        print("prompt_ids:\n{}".format(example["prompt_ids"]))
        print("prompt:\n{}".format(tokenizer.decode(example["prompt_ids"], skip_special_tokens=False)))
        print("chosen_ids:\n{}".format(example["chosen_ids"]))
        print("chosen:\n{}".format(tokenizer.decode(example["chosen_ids"], skip_special_tokens=False)))
        print("rejected_ids:\n{}".format(example["rejected_ids"]))
        print("rejected:\n{}".format(tokenizer.decode(example["rejected_ids"], skip_special_tokens=False)))

    def print_unsupervised_dataset_example(example):
        print("input_ids:\n{}".format(example["input_ids"]))
        print("inputs:\n{}".format(tokenizer.decode(example["input_ids"], skip_special_tokens=False)))

    if stage == "pt":
        dataset = dataset.filter(lambda example: example["prompt"])
        preprocess_function = preprocess_pretrain_dataset
        print_function = print_unsupervised_dataset_example
    elif stage == "sft" and not training_args.predict_with_generate:
        dataset = dataset.filter(lambda example: example["prompt"] and example["response"])
        preprocess_function = preprocess_supervised_dataset
        print_function = print_supervised_dataset_example
    elif stage == "rm":
        dataset = dataset.filter(lambda example: example["prompt"] and len(example["response"]) > 1)
        preprocess_function = preprocess_pairwise_dataset
        print_function = print_pairwise_dataset_example
    else:
        dataset = dataset.filter(lambda example: example["prompt"])
        preprocess_function = preprocess_unsupervised_dataset
        print_function = print_unsupervised_dataset_example

    with training_args.main_process_first(desc="dataset map pre-processing"):
        kwargs = {}
        if not data_args.streaming:
            kwargs = dict(
                num_proc=data_args.preprocessing_num_workers,
                load_from_cache_file=not data_args.overwrite_cache,
                desc="Running tokenizer on dataset"
            )

        dataset = dataset.map(
            preprocess_function,
            batched=True,            
            remove_columns=column_names,
            **kwargs
        )

        print_function(next(iter(dataset)))
        return dataset