AstrAI/astrai/trainer/train_context.py

156 lines
5.1 KiB
Python

from dataclasses import dataclass, field
from pathlib import Path
from typing import Optional, Self
import torch.nn as nn
from torch.utils.data import DataLoader
from astrai.config.train_config import TrainConfig
from astrai.dataset import ResumableDistributedSampler
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_model_weights
from astrai.trainer.strategy import BaseStrategy, StrategyFactory
@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)
executor: BaseExecutor = field(default=None)
epoch: int = field(default=0)
iteration: int = field(default=0)
loss: float = field(default=0.0)
val_dataloader: DataLoader = field(default=None)
val_loss: float = field(default=0.0)
world_size: int = field(default=1)
rank: int = field(default=0)
kwargs: dict = field(default_factory=dict)
class TrainContextBuilder:
def __init__(
self,
config: TrainConfig,
):
self.config = config
self._resume_dir: Optional[str] = None
def with_resume_dir(self, resume_dir: Optional[str]) -> Self:
self._resume_dir = resume_dir
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)
context = TrainContext(
model=model,
world_size=get_world_size(),
rank=get_rank(),
config=cfg,
executor=executor,
)
if self._resume_dir is not None:
resume_path = Path(self._resume_dir)
if (resume_path / "meta.json").exists():
checkpoint = Checkpoint.load(self._resume_dir)
state_dict = checkpoint.state_dict
else:
checkpoint = None
state_dict = load_model_weights(self._resume_dir)
model.load_state_dict(state_dict, strict=False)
if checkpoint is not None:
context.epoch = cfg.start_epoch
context.iteration = cfg.start_batch
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)
sampler_offset = context.iteration * cfg.batch_per_device
sampler = ResumableDistributedSampler(
data_source=cfg.dataset,
start_epoch=context.epoch,
start_iter=sampler_offset,
seed=cfg.random_seed,
)
context.dataloader = DataLoader(
cfg.dataset,
batch_size=cfg.batch_per_device,
sampler=sampler,
num_workers=cfg.num_workers,
pin_memory=cfg.pin_memory,
prefetch_factor=cfg.prefetch_factor,
)
if cfg.val_dataset is not None:
val_sampler = ResumableDistributedSampler(
data_source=cfg.val_dataset,
start_epoch=0,
start_iter=0,
seed=cfg.random_seed,
shuffle=False,
)
context.val_dataloader = DataLoader(
cfg.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,
)
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])
context.strategy = StrategyFactory.create(
model=context.model,
train_type=cfg.strategy,
device=device,
**cfg.extra_kwargs,
)
return context