Files
AstrAI/astrai/trainer/train_context.py
T
ViperEkura a74e5b91a3 feat: add record-mode to Store for DPO/GRPO
- Store gains fetch_record/num_records alongside stream fetch/__len__
- save_bin/load_bin support per-record offsets via record_keys param
- H5Store/MmapStore/JsonlStore all support dual stream+record access
- DPODataset/GRPODataset use fetch_record, no cross-record concat
- dpo_collate_fn + collate_fn wired through TrainConfig
- fixes attention context leakage in DPO from windowed concatenation
2026-07-18 21:02:29 +08:00

219 lines
7.4 KiB
Python

from dataclasses import dataclass, field
from pathlib import Path
from typing import Any, Dict, Optional, Self
import torch
import torch.nn as nn
from torch.utils.data import DataLoader, random_split
from astrai.config.train_config import TrainConfig
from astrai.dataset import RDSampler
from astrai.model.components.lora import inject_lora
from astrai.parallel.executor import BaseExecutor, ExecutorFactory
from astrai.parallel.setup import get_current_device, get_rank, get_world_size
from astrai.protocols import OptimizerProtocol, SchedulerProtocol
from astrai.serialization import Checkpoint, load_json
from astrai.trainer.strategy import BaseStrategy, StrategyFactory, create_ref_model
@dataclass
class TrainContext:
model: nn.Module = field(default=None)
strategy: BaseStrategy = field(default=None)
dataloader: DataLoader = field(default=None)
optimizer: OptimizerProtocol = field(default=None)
scheduler: SchedulerProtocol = field(default=None)
checkpoint: Checkpoint = field(default=None)
config: TrainConfig = field(default=None)
model_config: dict = field(default_factory=dict)
executor: BaseExecutor = field(default=None)
epoch: int = field(default=0)
consumed_samples: int = field(default=0)
loss: float = field(default=0.0)
grad_norm: Optional[float] = field(default=None)
val_dataloader: Optional[DataLoader] = field(default=None)
val_loss: Optional[float] = field(default=None)
world_size: int = field(default=1)
rank: int = field(default=0)
kwargs: Dict[str, Any] = field(default_factory=dict)
@property
def optimizer_step(self) -> int:
return self.consumed_samples // (
self.config.batch_per_device
* self.world_size
* self.config.grad_accum_steps
)
class TrainContextBuilder:
def __init__(
self,
config: TrainConfig,
):
self.config = config
self._param_path: Optional[str] = None
self._resume: bool = False
def with_param_path(self, param_path: Optional[str], resume: bool = False) -> Self:
self._param_path = param_path
self._resume = resume
return self
def build(self) -> TrainContext:
cfg = self.config
device = get_current_device()
executor = ExecutorFactory.create(
cfg.parallel_mode,
grad_accum_steps=cfg.grad_accum_steps,
**cfg.executor_kwargs,
)
model = cfg.model_fn()
model = model.to(device=device)
model_config = {}
if self._param_path:
config_path = Path(self._param_path) / "config.json"
if config_path.exists():
model_config = load_json(config_path)
if not model_config and hasattr(model, "config"):
model_config = model.config.to_dict()
context = TrainContext(
model=model,
world_size=get_world_size(),
rank=get_rank(),
config=cfg,
model_config=model_config,
executor=executor,
)
if self._param_path:
checkpoint = Checkpoint.load_any(self._param_path)
if checkpoint is not None:
model.load_state_dict(checkpoint.state_dict, strict=False)
if checkpoint.config:
context.model_config = checkpoint.config
if self._resume:
context.epoch = checkpoint.epoch or cfg.start_epoch
if checkpoint.consumed_samples > 0:
per_step = (
cfg.batch_per_device
* context.world_size
* cfg.grad_accum_steps
)
context.consumed_samples = (
checkpoint.consumed_samples // per_step
) * per_step
else:
context.consumed_samples = (
cfg.start_samples * context.world_size
)
context.checkpoint = checkpoint
if cfg.lora is not None:
inject_lora(
model,
r=cfg.lora.r,
alpha=cfg.lora.alpha,
target_modules=set(cfg.lora.target_modules),
)
context.optimizer = cfg.optimizer_fn(model)
context.scheduler = cfg.scheduler_fn(context.optimizer)
train_dataset = cfg.dataset
val_dataset = cfg.val_dataset
if val_dataset is None and cfg.val_split is not None:
n_total = len(cfg.dataset)
n_val = max(1, int(n_total * cfg.val_split))
n_train = n_total - n_val
generator = torch.Generator().manual_seed(cfg.random_seed)
train_dataset, val_dataset = random_split(
cfg.dataset, [n_train, n_val], generator=generator
)
sampler_offset = context.consumed_samples // context.world_size
sampler = RDSampler(
data_source=train_dataset,
start_epoch=context.epoch,
start_iter=sampler_offset,
seed=cfg.random_seed,
)
context.dataloader = DataLoader(
train_dataset,
batch_size=cfg.batch_per_device,
sampler=sampler,
num_workers=cfg.num_workers,
pin_memory=cfg.pin_memory,
prefetch_factor=cfg.prefetch_factor,
collate_fn=cfg.collate_fn,
)
if val_dataset is not None:
val_sampler = RDSampler(
data_source=val_dataset,
start_epoch=0,
start_iter=0,
seed=cfg.random_seed,
shuffle=False,
)
context.val_dataloader = DataLoader(
val_dataset,
batch_size=cfg.batch_per_device,
sampler=val_sampler,
num_workers=cfg.num_workers,
pin_memory=cfg.pin_memory,
prefetch_factor=cfg.prefetch_factor,
collate_fn=cfg.collate_fn,
)
context.model, context.optimizer, context.dataloader, context.scheduler = (
executor.prepare(
model,
context.optimizer,
context.dataloader,
context.scheduler,
)
)
if context.checkpoint and context.checkpoint.extra:
extra = context.checkpoint.extra
for name in ("optimizer", "scheduler"):
if name in extra:
obj = getattr(context, name, None)
if obj is not None:
obj.load_state_dict(extra[name])
strategy_kwargs = dict(cfg.extra_kwargs)
if cfg.strategy in ("dpo", "grpo"):
ref_model = create_ref_model(
cfg.model_fn, executor.unwrap_model(context.model)
).to(device=device)
strategy_kwargs["ref_model"] = ref_model
if cfg.strategy == "grpo":
old_model = create_ref_model(
cfg.model_fn, executor.unwrap_model(context.model)
).to(device=device)
strategy_kwargs["old_model"] = old_model
context.strategy = StrategyFactory.create(
cfg.strategy,
model=context.model,
device=device,
executor=executor,
model_fn=cfg.model_fn,
**strategy_kwargs,
)
return context