lerobot/lerobot/common/optim/factory.py

62 lines
2.7 KiB
Python

#!/usr/bin/env python
# Copyright 2024 The HuggingFace Inc. team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from pathlib import Path
import torch
from torch.optim import Optimizer
from torch.optim.lr_scheduler import LRScheduler
from lerobot.common.logger import TRAINING_STATE
from lerobot.common.policies.pretrained import PreTrainedPolicy
from lerobot.common.utils.utils import get_global_random_state, set_global_random_state
from lerobot.configs.train import TrainPipelineConfig
def make_optimizer_and_scheduler(
cfg: TrainPipelineConfig, policy: PreTrainedPolicy
) -> tuple[Optimizer, LRScheduler | None]:
"""Generates the optimizer and scheduler based on configs.
Args:
cfg (TrainPipelineConfig): The training config that contains optimizer and scheduler configs
policy (PreTrainedPolicy): The policy config from which parameters and presets must be taken from.
Returns:
tuple[Optimizer, LRScheduler | None]: The couple (Optimizer, Scheduler). Scheduler can be `None`.
"""
params = policy.get_optim_params() if cfg.use_policy_training_preset else policy.parameters()
optimizer = cfg.optimizer.build(params)
lr_scheduler = cfg.scheduler.build(optimizer, cfg.offline.steps) if cfg.scheduler is not None else None
return optimizer, lr_scheduler
def load_training_state(checkpoint_dir: Path, optimizer: Optimizer, scheduler: LRScheduler | None) -> int:
"""
Given the checkpoint directory, load the optimizer state, scheduler state, and random state, and
return the global training step.
"""
# TODO(aliberts): use safetensors instead as weights_only=False is unsafe
training_state = torch.load(checkpoint_dir / TRAINING_STATE, weights_only=False)
optimizer.load_state_dict(training_state["optimizer"])
if scheduler is not None:
scheduler.load_state_dict(training_state["scheduler"])
elif "scheduler" in training_state:
raise ValueError("The checkpoint contains a scheduler state_dict, but no LRScheduler was provided.")
# Small HACK to get the expected keys: use `get_global_random_state`.
set_global_random_state({k: training_state[k] for k in get_global_random_state()})
return training_state["step"], optimizer, scheduler