Files
AstrAI/astrai/preprocessing/transform.py
T
ViperEkura b33250dc28 refactor: decouple tokenizer from Store into Transform layer
- Extract tokenization/mask/position logic from JsonlStore into TokenizeTransform
- JsonlStore now pure reader: reads JSON records, delegates to transform
- Store no longer imports tokenizer or preprocessing components
- Replace per_record param with segments_are_records class attribute
- Store subclasses declare segment semantics as format-level property
2026-07-18 21:37:31 +08:00

104 lines
3.8 KiB
Python

"""Tokenization transform for JSONL record streams.
Bridges the Reader layer (``JsonlStore`` reads raw JSON records) and the
Dataset layer (expects per-record tensors). Holds the tokenizer,
mask-builder and position-id strategy together so that I/O code stays
free of model dependencies.
"""
import json
from pathlib import Path
from typing import Dict, List
import torch
from astrai.config.preprocess_config import PipelineConfig
from astrai.preprocessing.builder import MaskBuilderFactory
from astrai.preprocessing.position_id import PositionIdStrategyFactory
from astrai.tokenize import AutoTokenizer
class TokenizeTransform:
"""Tokenize raw JSONL record dicts into per-key tensor lists.
Owns the three preprocessing concerns that were previously inlined in
``JsonlStore``: tokenization, loss-mask construction and position-id
generation. Constructing it loads the tokenizer, so it is intentionally
cheap to pass around once built.
Args:
config: Pipeline config describing sections / masks / position mode.
tokenizer_path: Path passed to ``AutoTokenizer.from_pretrained``.
"""
def __init__(self, config: PipelineConfig, tokenizer_path: str):
self.config = config
self.tokenizer = AutoTokenizer.from_pretrained(tokenizer_path)
self.mask_builder = MaskBuilderFactory.create("sectioned")
self.position_strategy = PositionIdStrategyFactory.create(
config.output.position_ids_mode
)
@classmethod
def from_config_file(cls, config_path: str) -> "TokenizeTransform":
"""Build from a ``dataset_config.json`` file path.
The config file follows :class:`PipelineConfig` schema with an
extra ``tokenizer_path`` field. When omitted, the config's
parent directory is used as the tokenizer path.
"""
root = Path(config_path).parent
with open(config_path, "r", encoding="utf-8") as f:
raw_config = json.load(f)
tokenizer_path = raw_config.pop("tokenizer_path", None) or str(root)
config = PipelineConfig.from_dict(raw_config)
return cls(config, tokenizer_path)
def apply(self, records: List[dict]) -> Dict[str, list]:
"""Tokenize a list of raw record dicts.
Returns a dict mapping key (``sequence``, ``chosen``, ``responses``,
…) to a list of per-record tensors (or nested tensor lists for
multi-response keys such as GRPO ``responses``).
"""
raw: Dict[str, list] = {}
doc_sequences: List[List[int]] = []
for item in records:
result = self.mask_builder.build(item, self.config, self.tokenizer)
if result is None:
continue
result.pop("domain", None)
primary_ids = self._primary_ids(result)
if not primary_ids:
continue
doc_sequences.append(primary_ids)
for key, ids in result.items():
if key not in raw:
raw[key] = []
if ids and isinstance(ids[0], list):
raw[key].append(
[torch.tensor(sub, dtype=self._infer_dtype(sub)) for sub in ids]
)
else:
raw[key].append(torch.tensor(ids, dtype=self._infer_dtype(ids)))
pos_ids = self.position_strategy.generate(doc_sequences)
if pos_ids:
raw["position_ids"] = [torch.tensor(pos_ids, dtype=torch.int32)]
return raw
@staticmethod
def _primary_ids(result: dict) -> List[int]:
for val in result.values():
if isinstance(val, list) and val and isinstance(val[0], int):
return val
return []
@staticmethod
def _infer_dtype(ids: List) -> torch.dtype:
if ids and isinstance(ids[0], float):
return torch.float32
return torch.int32