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lerobot/src/lerobot/rl/data_sources/data_mixer.py
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Steven Palma 7e0fd0d653 refactor(types): change module name (#4232)
* refactor(types): change module name

Co-authored-by: saiteja6006 <saiteja6006@gmail.com>

* chore(test): remove package import test

* chore: remove ruff exception

---------

Co-authored-by: saiteja6006 <saiteja6006@gmail.com>
2026-07-30 15:27:51 +02:00

98 lines
3.1 KiB
Python

# Copyright 2026 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 __future__ import annotations
import abc
from lerobot.lerobot_types import BatchType
from ..buffer import ReplayBuffer, concatenate_batch_transitions
class DataMixer(abc.ABC):
"""Abstract interface for all data mixing strategies."""
@abc.abstractmethod
def sample(self, batch_size: int) -> BatchType:
"""Draw one batch of ``batch_size`` transitions."""
raise NotImplementedError
def get_iterator(
self,
batch_size: int,
async_prefetch: bool = True,
queue_size: int = 2,
):
"""Infinite iterator that yields batches."""
while True:
yield self.sample(batch_size)
class OnlineOfflineMixer(DataMixer):
"""Mixes transitions from an online and an offline replay buffer."""
def __init__(
self,
online_buffer: ReplayBuffer,
offline_buffer: ReplayBuffer | None = None,
online_ratio: float = 1.0,
):
if not 0.0 <= online_ratio <= 1.0:
raise ValueError(f"online_ratio must be in [0, 1], got {online_ratio}")
self.online_buffer = online_buffer
self.offline_buffer = offline_buffer
self.online_ratio = online_ratio
def sample(self, batch_size: int) -> BatchType:
if self.offline_buffer is None:
return self.online_buffer.sample(batch_size)
n_online = max(1, int(batch_size * self.online_ratio))
n_offline = batch_size - n_online
online_batch = self.online_buffer.sample(n_online)
offline_batch = self.offline_buffer.sample(n_offline)
return concatenate_batch_transitions(online_batch, offline_batch)
def get_iterator(
self,
batch_size: int,
async_prefetch: bool = True,
queue_size: int = 2,
):
"""Yield batches by composing buffer async iterators."""
n_online = max(1, int(batch_size * self.online_ratio))
online_iter = self.online_buffer.get_iterator(
batch_size=n_online,
async_prefetch=async_prefetch,
queue_size=queue_size,
)
if self.offline_buffer is None:
yield from online_iter
return
n_offline = batch_size - n_online
offline_iter = self.offline_buffer.get_iterator(
batch_size=n_offline,
async_prefetch=async_prefetch,
queue_size=queue_size,
)
while True:
yield concatenate_batch_transitions(next(online_iter), next(offline_iter))