mirror of
https://github.com/google-deepmind/deepmind-research.git
synced 2026-05-09 21:07:49 +08:00
Florent Altché
106 lines
3.5 KiB
Python
106 lines
3.5 KiB
Python
# Copyright 2020 DeepMind Technologies Limited.
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#
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# https://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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"""Checkpoint saving and restoring utilities."""
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import os
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import time
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from typing import Mapping, Text, Tuple, Union
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from absl import logging
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import dill
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import jax
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import jax.numpy as jnp
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from byol.utils import helpers
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class Checkpointer:
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"""A checkpoint saving and loading class."""
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def __init__(
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self,
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use_checkpointing: bool,
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checkpoint_dir: Text,
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save_checkpoint_interval: int,
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filename: Text):
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if (not use_checkpointing or
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checkpoint_dir is None or
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save_checkpoint_interval <= 0):
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self._checkpoint_enabled = False
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return
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self._checkpoint_enabled = True
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self._checkpoint_dir = checkpoint_dir
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os.makedirs(self._checkpoint_dir, exist_ok=True)
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self._filename = filename
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self._checkpoint_path = os.path.join(self._checkpoint_dir, filename)
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self._last_checkpoint_time = 0
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self._checkpoint_every = save_checkpoint_interval
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def maybe_save_checkpoint(
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self,
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experiment_state: Mapping[Text, jnp.ndarray],
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step: int,
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rng: jnp.ndarray,
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is_final: bool):
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"""Saves a checkpoint if enough time has passed since the previous one."""
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current_time = time.time()
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if (not self._checkpoint_enabled or
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jax.host_id() != 0 or # Only checkpoint the first worker.
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(not is_final and
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current_time - self._last_checkpoint_time < self._checkpoint_every)):
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return
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checkpoint_data = dict(
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experiment_state=jax.tree_map(
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lambda x: jax.device_get(x[0]), experiment_state),
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step=step,
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rng=rng)
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with open(self._checkpoint_path + '_tmp', 'wb') as checkpoint_file:
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dill.dump(checkpoint_data, checkpoint_file, protocol=2)
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try:
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os.rename(self._checkpoint_path, self._checkpoint_path + '_old')
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remove_old = True
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except FileNotFoundError:
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remove_old = False # No previous checkpoint to remove
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os.rename(self._checkpoint_path + '_tmp', self._checkpoint_path)
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if remove_old:
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os.remove(self._checkpoint_path + '_old')
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self._last_checkpoint_time = current_time
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def maybe_load_checkpoint(
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self) -> Union[Tuple[Mapping[Text, jnp.ndarray], int, jnp.ndarray], None]:
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"""Loads a checkpoint if any is found."""
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checkpoint_data = load_checkpoint(self._checkpoint_path)
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if checkpoint_data is None:
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logging.info('No existing checkpoint found at %s', self._checkpoint_path)
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return None
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step = checkpoint_data['step']
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rng = checkpoint_data['rng']
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experiment_state = jax.tree_map(
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helpers.bcast_local_devices, checkpoint_data['experiment_state'])
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del checkpoint_data
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return experiment_state, step, rng
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def load_checkpoint(checkpoint_path):
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try:
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with open(checkpoint_path, 'rb') as checkpoint_file:
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checkpoint_data = dill.load(checkpoint_file)
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logging.info('Loading checkpoint from %s, saved at step %d',
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checkpoint_path, checkpoint_data['step'])
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return checkpoint_data
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except FileNotFoundError:
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return None
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