docs: sync architecture/dataflow/training/params with code

- dataflow.md: update DatasetFactory.load signature, stream vs record access, Store._offsets
- architecture.md: add tokenizer to Pipeline, TokenizeTransform class, RecordDataset, Streamable/Recordable mixins, fix GRPOStrategy (old_model/sync_old_model)
- training.md: DPO reduction="sum", GRPO rho_t uses pi_old, gradient_clipping always registered
- params.md: --max_grad_norm default None
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2026-07-19 12:33:35 +08:00
parent 31c22dc043
commit d655b65027
4 changed files with 112 additions and 40 deletions
+36 -18
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@@ -61,41 +61,59 @@ StoreFactory.create("bin") → MmapStore
StoreFactory.create("jsonl") → JsonlStore
```
**H5Store**: Reads HDF5 files. Tensors are loaded into host memory and normalized into segmented storage.
All three inherit `Store` (base, owns `_data`/`_cum`/`_offsets`/`_normalize`) plus the `Streamable` and `Recordable` mixins, so every backend supports both `fetch(begin, end, keys)` (stream) and `fetch_record(index, keys)` (record) APIs.
**MmapStore**: Memory-maps `.bin` files. OS page cache sharing is native — no explicit `share_memory_()` needed. Uses `torch.from_numpy(np.memmap(...))`.
**H5Store**: Reads HDF5 files. Tensors are loaded into host memory and normalized into segmented storage. `segments_are_records=True` — each `data_i` dataset is one record.
**JsonlStore**: On-the-fly tokenization of raw JSONL files at load time. Requires a `dataset_config.json` alongside the `.jsonl` files following the same `PipelineConfig` schema with an additional `tokenizer_path` field.
**MmapStore**: Memory-maps `.bin` files. OS page cache sharing is native — no explicit `share_memory_()` needed. Uses `torch.from_numpy(np.memmap(...))`. `segments_are_records=False` — bin segments are contiguous streams; record access is driven by `_offsets` (written when `save_bin(..., record_keys=...)` was used at preprocessing time).
All backends normalise tensors into `Store._data[Dict[str, List[Tensor]]]` + `Store._cum[Dict[str, List[int]]]` (cumulative lengths for bisect-based indexing).
**JsonlStore**: On-the-fly tokenization of raw JSONL files at load time. Requires a `dataset_config.json` alongside the `.jsonl` files following the same `PipelineConfig` schema with an additional `tokenizer_path` field. Two modes: eager (default, applies `TokenizeTransform` to all records at load) and lazy (`processor=fn` given, defers tokenisation to `fetch_record` — used by DPO/GRPO).
All backends normalise tensors into `Store._data[Dict[str, List[Tensor]]]` + `Store._cum[Dict[str, List[int]]]` (cumulative lengths for bisect-based stream indexing) + `Store._offsets[Dict[str, List[int]]]` (per-record offsets for record-mode indexing). Nested keys (GRPO `responses`/`masks` as `List[List[Tensor]]`) are stored as-is and excluded from both bookkeepings — they are only accessed record-by-record.
## Data Keys by Training Type
| Type | Storage Keys |
|------|-------------|
| `seq` | `sequence` (→ input_ids, target_ids via offset-by-1) |
| `sft` | `sequence`, `loss_mask`, `position_ids` |
| `dpo` | `chosen`, `rejected`, `chosen_mask`, `rejected_mask` |
| `grpo` | `prompts`, `responses`, `masks`, `rewards` |
| Type | Storage Keys | Access Mode |
|------|-------------|-------------|
| `seq` | `sequence` (→ input_ids, target_ids via offset-by-1) | stream (`fetch`) |
| `sft` | `sequence`, `loss_mask`, `position_ids` | stream (`fetch`) |
| `dpo` | `chosen`, `rejected`, `chosen_mask`, `rejected_mask` | record (`fetch_record`) |
| `grpo` | `prompts`, `responses`, `masks`, `rewards` | record (`fetch_record`) |
## Dataset Architecture
```
DatasetFactory.load(train_type, load_path, window_size, stride=None, storage_type=None)
DatasetFactory.load(train_type, load_path, window_size, stride=None,
storage_type=None, tokenizer_path=None,
max_len=2048, store=None)
→ BaseDataset.load(load_path, storage_type=None)
→ detect_format(load_path)
→ StoreFactory.create(storage_type)
→ Store.load(load_path)
→ _normalize(raw) # base Store, shared by both backends
→ Store._data[Dict[str, List[Tensor]]] + _cum[Dict[str, List[int]]]
→ BaseDataset.__getitem__(idx)
→ get_index(idx) → [begin, end)
→ Store.fetch(begin, end, keys) → Tensor / Dict[str, Tensor]
→ Store._data[Dict[str, List[Tensor]]]
+ _cum[Dict[str, List[int]]] (stream mode)
+ _offsets[Dict[str, List[int]]] (record mode)
Stream datasets (SEQ/SFT):
BaseDataset.__getitem__(idx)
→ get_index(idx) → [begin, end)
→ Store.fetch(begin, end, keys) → Tensor / Dict[str, Tensor]
Record datasets (DPO/GRPO via RecordDataset):
RecordDataset.__getitem__(idx)
→ Store.fetch_record(idx, keys) → Tensor / Dict[str, Tensor]
```
`window_size` = max input length, `stride` = step between consecutive samples (defaults to `window_size`, optional). `storage_type` defaults to `None` (auto-detect via `detect_format`).
Class hierarchy: `BaseDataset``SEQDataset` / `SFTDataset` (stream); `BaseDataset``RecordDataset``DPODataset` / `GRPODataset` (record).
`Store.fetch(begin, end, keys)` accepts a single key (`str`) returning a `Tensor`, or a list of keys returning `Dict[str, Tensor]`. Internally uses `bisect` across multi-segment tensors. Raises `RuntimeError("Store not loaded")` if called before `load()`.
`window_size` = max input length, `stride` = step between consecutive samples (defaults to `window_size`, optional). Only meaningful for stream datasets — record datasets ignore both. `storage_type` defaults to `None` (auto-detect via `detect_format`).
`tokenizer_path` triggers lazy on-the-fly tokenisation for record datasets on raw JSONL (DPO builds a `dpo_processor`; SEQ/SFT/pre-tokenised backends ignore it). `store` (pre-built `Store`) bypasses `load_path`/`storage_type`/`tokenizer_path` entirely — the caller controls Store construction.
`Store.fetch(begin, end, keys)` (stream mode, on `Streamable`): accepts a single key (`str`) returning a `Tensor`, or a list of keys returning `Dict[str, Tensor]`. Internally uses `bisect` across multi-segment tensors. Raises `RuntimeError("Store not loaded")` if called before `load()`.
`Store.fetch_record(index, keys)` (record mode, on `Recordable`): same key API. Uses `_offsets[key]` when present (bin layout with per-record offsets), otherwise indexes `_data[key]` directly (H5/JSONL where each segment is one record).
## Sampler
@@ -109,4 +127,4 @@ DatasetFactory.load(train_type, load_path, window_size, stride=None, storage_typ
Standard PyTorch `DataLoader` with configurable `batch_size`, `num_workers`, `pin_memory`, `prefetch_factor`. Sampler produces indices; dataloader fetches tensor batches via `__getitem__`.
> Document Update Time: 2026-07-09
> Document Update Time: 2026-07-19