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ViperEkura 31c22dc043 refactor: deduplicate preprocessing kernel and BFD packing
- Extract shared core (mask building, primary-id extraction, tensorisation, position-id generation) to astrai/preprocessing/core.py; Pipeline and TokenizeTransform both consume it, eliminating ~60% duplicated logic
- Promote BFD _plan to module-level plan_bfd(lengths, max_len) returning pure index bins; BFDPacking.apply and evaluate_ifd._pack_bins both call it, removing the second BFD implementation
- Split Pipeline._flush (49 lines) into _inject_doc_reset_position_ids + _inject_continuous_position_ids + _to_tensors; split Pipeline.run by delegating record iteration to core.iter_raw_records
- Remove dead no-op pop/塞回 in Pipeline.run (L110-111)
2026-07-19 12:27:56 +08:00

125 lines
4.3 KiB
Python

"""Shared preprocessing kernel used by both :class:`Pipeline` and
:class:`TokenizeTransform`.
The two entry points previously duplicated ~60 % of their logic:
record iteration, mask-builder invocation, primary-id extraction,
per-key accumulation, dtype inference and position-id generation.
This module factors out the common core as pure functions so that
the online (``TokenizeTransform``) and offline (``Pipeline``) paths
stay in lockstep.
"""
from itertools import chain
from typing import Dict, Iterator, List, Optional
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
def build_preprocessing_components(config: PipelineConfig, tokenizer_path: str):
"""Load tokenizer, mask builder and position-id strategy together.
Both ``Pipeline`` and ``TokenizeTransform`` need the same triple;
centralising the construction avoids drift (e.g. one path forgetting
to create the position-id strategy).
"""
tokenizer = AutoTokenizer.from_pretrained(tokenizer_path)
mask_builder = MaskBuilderFactory.create("sectioned")
position_strategy = PositionIdStrategyFactory.create(
config.output.position_ids_mode
)
return tokenizer, mask_builder, position_strategy
def primary_ids(result: dict) -> List[int]:
"""Return the first flat int-list value in *result*.
Used for token counting and position-id generation when the
primary key name is not known (DPO uses ``chosen``, GRPO uses
``prompts``, SFT uses ``sequence``).
"""
for val in result.values():
if isinstance(val, list) and val and isinstance(val[0], int):
return val
return []
def infer_dtype(ids: List) -> torch.dtype:
"""Float values become float32, everything else int32."""
if ids and isinstance(ids[0], float):
return torch.float32
return torch.int32
def iter_raw_records(
records: List[dict],
mask_builder,
config: PipelineConfig,
tokenizer,
) -> Iterator[dict]:
"""Yield mask-builder output dicts for each record, skipping failures.
Drops ``domain`` from the result (callers that need it should read
it before calling this). Each yielded dict maps a key
(``sequence``, ``chosen``, ``responses``…) to either a flat
``List[int]`` or a nested ``List[List[int]]`` (GRPO responses/masks).
"""
for item in records:
result = mask_builder.build(item, config, tokenizer)
if result is None:
continue
result.pop("domain", None)
if not primary_ids(result):
continue
yield result
def to_per_record_tensors(
raw: Dict[str, list],
) -> Dict[str, List[torch.Tensor]]:
"""Convert an accumulated ``{key: [per-record ids]}`` dict to tensors.
Handles three shapes transparently:
- ``List[int]`` per record (``sequence``, ``chosen``…) → one tensor per record.
- ``List[List[int]]`` per record (GRPO ``responses``/``masks``) → one
``List[Tensor]`` per record (nested), preserving the per-response
boundary so downstream code can index responses individually.
- ``List[int]`` for the whole shard (pre-packed keys) → single tensor.
The detection mirrors the previous inline logic in
``Pipeline._flush`` and ``TokenizeTransform.apply``.
"""
tensors: Dict[str, List[torch.Tensor]] = {}
for key, ids_list in raw.items():
if ids_list and isinstance(ids_list[0], list):
tensors[key] = [
[torch.tensor(sub, dtype=infer_dtype(sub)) for sub in ids]
if ids and isinstance(ids[0], list)
else torch.tensor(ids, dtype=infer_dtype(ids))
for ids in ids_list
]
else:
tensors[key] = [
torch.tensor(list(chain.from_iterable(ids_list)), dtype=torch.int32)
]
return tensors
def build_position_ids(
sequences: List[List[int]],
strategy,
) -> Optional[List[int]]:
"""Generate position ids for *sequences* using *strategy*.
Returns ``None`` when the strategy produces no ids (e.g. ``none``
mode), so callers can skip attaching the key instead of storing
an empty list.
"""
pos_ids = strategy.generate(sequences)
return pos_ids or None