ColossalAI/applications/Chat/coati/replay_buffer/naive.py

58 lines
2.0 KiB
Python

import random
from typing import List
import torch
from coati.experience_maker.base import Experience
from .base import ReplayBuffer
from .utils import BufferItem, make_experience_batch, split_experience_batch
class NaiveReplayBuffer(ReplayBuffer):
"""Naive replay buffer class. It stores experience.
Args:
sample_batch_size (int): Batch size when sampling.
limit (int, optional): Limit of number of experience samples. A number <= 0 means unlimited. Defaults to 0.
cpu_offload (bool, optional): Whether to offload experience to cpu when sampling. Defaults to True.
"""
def __init__(self, sample_batch_size: int, limit: int = 0, cpu_offload: bool = True) -> None:
super().__init__(sample_batch_size, limit)
self.cpu_offload = cpu_offload
self.target_device = torch.device(f'cuda:{torch.cuda.current_device()}')
# TODO(ver217): add prefetch
self.items: List[BufferItem] = []
@torch.no_grad()
def append(self, experience: Experience) -> None:
if self.cpu_offload:
experience.to_device(torch.device('cpu'))
items = split_experience_batch(experience)
self.items.extend(items)
if self.limit > 0:
samples_to_remove = len(self.items) - self.limit
if samples_to_remove > 0:
self.items = self.items[samples_to_remove:]
def clear(self) -> None:
self.items.clear()
@torch.no_grad()
def sample(self) -> Experience:
items = random.sample(self.items, self.sample_batch_size)
experience = make_experience_batch(items)
if self.cpu_offload:
experience.to_device(self.target_device)
return experience
def __len__(self) -> int:
return len(self.items)
def __getitem__(self, idx: int) -> BufferItem:
return self.items[idx]
def collate_fn(self, batch) -> Experience:
experience = make_experience_batch(batch)
return experience