EasyCV/easycv/datasets/loader/sampler.py

470 lines
17 KiB
Python

# Copyright (c) Alibaba, Inc. and its affiliates.
from __future__ import division
import math
import os
import random
import numpy as np
import torch
from mmcv.runner import get_dist_info
from torch.utils.data import DistributedSampler as _DistributedSampler
from torch.utils.data import Sampler
class DistributedMPSampler(_DistributedSampler):
def __init__(self,
dataset,
num_replicas=None,
rank=None,
shuffle=True,
split_huge_listfile_byrank=False):
""" A Distribute sampler which support sample m instance from one class once for classification dataset
dataset: pytorch dataset object
num_replicas (optional): Number of processes participating in
distributed training.
rank (optional): Rank of the current process within num_replicas.
shuffle (optional): If true (default), sampler will shuffle the indices
split_huge_listfile_byrank: if split, return all indice for each rank, because list for each rank has been
split before build dataset in dist training
"""
super().__init__(dataset, num_replicas=num_replicas, rank=rank)
current_env = os.environ.copy()
self.local_rank = int(current_env['LOCAL_RANK'])
self.shuffle = shuffle
self.unif_sampling_flag = False
self.split_huge_listfile_byrank = split_huge_listfile_byrank
self.get_label_dict()
def __iter__(self):
# deterministically shuffle based on epoch
indice_list = self.generate_indice()
return iter(indice_list)
def generate_indice(self):
if self.shuffle:
random.shuffle(self.label_list)
for k in self.label_dict.keys():
random.shuffle(self.label_dict[k])
this_label_list, this_label_list_size = self.calculate_this_label_list(
)
if self.rank == 0:
print('Each epoch has %d buckets of M imgs for per class' %
(self.buckets_num))
m_per_class = self.dataset.m_per_class
indice_list = [] # [this_label_list_size x (m * buckets_num)]
for label in this_label_list:
idx_list = self.label_dict[label]
if len(idx_list) < self.buckets_num * m_per_class:
# this place need(could) add more random .
idx_list = idx_list * int(self.buckets_num * m_per_class /
len(idx_list) + 1)
idx_list = idx_list[0:self.buckets_num * m_per_class]
indice_list.append(idx_list)
indice_list = np.array(indice_list).reshape(
(this_label_list_size * self.buckets_num), m_per_class)
if self.shuffle:
np.random.shuffle(indice_list)
indice_list = list(indice_list.astype(int).flatten())
return indice_list
def get_label_dict(self):
self.label_dict = {}
self.label_list = []
if not self.dataset.data_source.has_labels:
raise 'MPSampler need initial with classification datasets which has label!'
for idx, label in enumerate(self.dataset.data_source.labels):
if label in self.label_dict.keys():
self.label_dict[label].append(idx)
else:
self.label_dict[label] = [idx]
self.label_list.append(label)
if self.rank == 0:
print(
self.rank, ' : Total %d Label in %s' %
(len(self.label_list), type(self.dataset)))
# calculate the After mpsampler, dataset length change and buckets_num
self.calculate_this_label_list()
if self.rank == 0:
print('Before original dataset length is %d' %
self.dataset.data_source.get_length())
print('After MPRefine dataset length is %d' % (self.length))
print('Total %d Label in %s' %
(len(self.label_list), type(self.dataset)))
return
def calculate_this_label_list(self):
label_size = len(self.label_list)
if not self.split_huge_listfile_byrank:
refine_label_size = int(1 + label_size /
self.num_replicas) * self.num_replicas
refine_label_list = self.label_list + self.label_list[0:(
refine_label_size - label_size)]
this_label_list_size = int(
len(refine_label_list) / self.num_replicas)
this_label_list = refine_label_list[self.rank *
this_label_list_size:
(self.rank + 1) *
this_label_list_size]
m_per_class = self.dataset.m_per_class
self.buckets_num = int(
int(self.dataset.data_source.get_length() / self.num_replicas)
/ (m_per_class * this_label_list_size)) + 1
self.length = self.buckets_num * m_per_class * int(
1 +
len(self.label_list) / self.num_replicas) # self.num_replicas
else:
this_label_list = self.label_list
this_label_list_size = label_size
m_per_class = self.dataset.m_per_class
# this is a huge bug for split situation
buckets_num = torch.Tensor([
int(self.dataset.data_source.get_length() /
(m_per_class * this_label_list_size))
]).to(self.local_rank)
torch.distributed.all_reduce(buckets_num,
torch.distributed.ReduceOp.MIN)
torch.distributed.barrier()
self.buckets_num = int(max(buckets_num, 1))
self.length = self.buckets_num * m_per_class * int(
len(self.label_list))
return this_label_list, this_label_list_size
def __len__(self):
return self.length
class DistributedSampler(_DistributedSampler):
def __init__(
self,
dataset,
num_replicas=None,
rank=None,
shuffle=True,
replace=False,
split_huge_listfile_byrank=False,
):
""" A Distribute sampler which support sample m instance from one class once for classification dataset
Args:
dataset: pytorch dataset object
num_replicas (optional): Number of processes participating in
distributed training.
rank (optional): Rank of the current process within num_replicas.
shuffle (optional): If true (default), sampler will shuffle the indices
split_huge_listfile_byrank: if split, return all indice for each rank, because list for each rank has been
split before build dataset in dist training
"""
super().__init__(dataset, num_replicas=num_replicas, rank=rank)
self.shuffle = shuffle
self.replace = replace
self.unif_sampling_flag = False
self.split_huge_listfile_byrank = split_huge_listfile_byrank
def __iter__(self):
# deterministically shuffle based on epoch
if not self.unif_sampling_flag:
self.generate_new_list()
else:
self.unif_sampling_flag = False
if not self.split_huge_listfile_byrank:
return iter(
self.indices[self.rank * self.num_samples:(self.rank + 1) *
self.num_samples])
else:
return iter(self.indices)
def generate_new_list(self):
if self.shuffle:
g = torch.Generator()
g.manual_seed(self.epoch)
if self.replace:
indices = torch.randint(
low=0,
high=len(self.dataset),
size=(len(self.dataset), ),
generator=g).tolist()
else:
indices = torch.randperm(
len(self.dataset), generator=g).tolist()
else:
indices = torch.arange(len(self.dataset)).tolist()
# add extra samples to make it evenly divisible
indices += indices[:(self.total_size - len(indices))]
assert len(indices) == self.total_size
self.indices = indices
def set_uniform_indices(self, labels, num_classes):
self.unif_sampling_flag = True
assert self.shuffle, 'Using uniform sampling, the indices must be shuffled.'
np.random.seed(self.epoch)
assert (len(labels) == len(self.dataset))
N = len(labels)
size_per_label = int(N / num_classes) + 1
indices = []
images_lists = [[] for i in range(num_classes)]
for i, l in enumerate(labels):
images_lists[l].append(i)
for i, l in enumerate(images_lists):
if len(l) == 0:
continue
indices.extend(
np.random.choice(
l, size_per_label, replace=(len(l) <= size_per_label)))
indices = np.array(indices)
np.random.shuffle(indices)
indices = indices[:N].astype(np.int).tolist()
# add extra samples to make it evenly divisible
assert len(indices) <= self.total_size, \
'{} vs {}'.format(len(indices), self.total_size)
indices += indices[:(self.total_size - len(indices))]
assert len(indices) == self.total_size, \
'{} vs {}'.format(len(indices), self.total_size)
self.indices = indices
def __len__(self):
return self.num_samples if not self.split_huge_listfile_byrank else self.num_samples * self.num_replicas
class GroupSampler(Sampler):
def __init__(self, dataset, samples_per_gpu=1):
assert hasattr(dataset, 'flag')
self.dataset = dataset
self.samples_per_gpu = samples_per_gpu
self.flag = dataset.flag.astype(np.int64)
self.group_sizes = np.bincount(self.flag)
self.num_samples = 0
for i, size in enumerate(self.group_sizes):
self.num_samples += int(np.ceil(
size / self.samples_per_gpu)) * self.samples_per_gpu
def __iter__(self):
indices = []
for i, size in enumerate(self.group_sizes):
if size == 0:
continue
indice = np.where(self.flag == i)[0]
assert len(indice) == size
np.random.shuffle(indice)
num_extra = int(np.ceil(size / self.samples_per_gpu)
) * self.samples_per_gpu - len(indice)
indice = np.concatenate(
[indice, np.random.choice(indice, num_extra)])
indices.append(indice)
indices = np.concatenate(indices)
indices = [
indices[i * self.samples_per_gpu:(i + 1) * self.samples_per_gpu]
for i in np.random.permutation(
range(len(indices) // self.samples_per_gpu))
]
indices = np.concatenate(indices)
indices = indices.astype(np.int64).tolist()
assert len(indices) == self.num_samples
return iter(indices)
def __len__(self):
return self.num_samples
class DistributedGroupSampler(Sampler):
"""Sampler that restricts data loading to a subset of the dataset.
It is especially useful in conjunction with
:class:`torch.nn.parallel.DistributedDataParallel`. In such case, each
process can pass a DistributedSampler instance as a DataLoader sampler,
and load a subset of the original dataset that is exclusive to it.
.. note::
Dataset is assumed to be of constant size.
Args:
dataset: Dataset used for sampling.
num_replicas (optional): Number of processes participating in
distributed training.
rank (optional): Rank of the current process within num_replicas.
"""
def __init__(self,
dataset,
samples_per_gpu=1,
num_replicas=None,
rank=None):
_rank, _num_replicas = get_dist_info()
if num_replicas is None:
num_replicas = _num_replicas
if rank is None:
rank = _rank
self.dataset = dataset
self.samples_per_gpu = samples_per_gpu
self.num_replicas = num_replicas
self.rank = rank
self.epoch = 0
assert hasattr(self.dataset, 'flag')
self.flag = self.dataset.flag
self.group_sizes = np.bincount(self.flag)
self.num_samples = 0
for i, j in enumerate(self.group_sizes):
self.num_samples += int(
math.ceil(self.group_sizes[i] * 1.0 / self.samples_per_gpu /
self.num_replicas)) * self.samples_per_gpu
self.total_size = self.num_samples * self.num_replicas
def __iter__(self):
# deterministically shuffle based on epoch
g = torch.Generator()
g.manual_seed(self.epoch)
indices = []
for i, size in enumerate(self.group_sizes):
if size > 0:
indice = np.where(self.flag == i)[0]
assert len(indice) == size
indice = indice[list(torch.randperm(int(size),
generator=g))].tolist()
extra = int(
math.ceil(
size * 1.0 / self.samples_per_gpu / self.num_replicas)
) * self.samples_per_gpu * self.num_replicas - len(indice)
# pad indice
tmp = indice.copy()
for _ in range(extra // size):
indice.extend(tmp)
indice.extend(tmp[:extra % size])
indices.extend(indice)
assert len(indices) == self.total_size
indices = [
indices[j] for i in list(
torch.randperm(
len(indices) // self.samples_per_gpu, generator=g))
for j in range(i * self.samples_per_gpu, (i + 1) *
self.samples_per_gpu)
]
# subsample
offset = self.num_samples * self.rank
indices = indices[offset:offset + self.num_samples]
assert len(indices) == self.num_samples
return iter(indices)
def __len__(self):
return self.num_samples
def set_epoch(self, epoch):
self.epoch = epoch
class DistributedGivenIterationSampler(Sampler):
def __init__(self,
dataset,
total_iter,
batch_size,
num_replicas=None,
rank=None,
last_iter=-1):
rank, world_size = get_dist_info()
assert rank < world_size
self.dataset = dataset
self.total_iter = total_iter
self.batch_size = batch_size
self.world_size = world_size
self.rank = rank
self.last_iter = last_iter
self.total_size = self.total_iter * self.batch_size
self.indices = self.gen_new_list()
def __iter__(self):
return iter(self.indices[(self.last_iter + 1) * self.batch_size:])
def set_uniform_indices(self, labels, num_classes):
np.random.seed(0)
assert (len(labels) == len(self.dataset))
N = len(labels)
size_per_label = int(N / num_classes) + 1
indices = []
images_lists = [[] for i in range(num_classes)]
for i, l in enumerate(labels):
images_lists[l].append(i)
for i, l in enumerate(images_lists):
if len(l) == 0:
continue
indices.extend(
np.random.choice(
l, size_per_label, replace=(len(l) <= size_per_label)))
indices = np.array(indices)
np.random.shuffle(indices)
indices = indices[:N].astype(np.int)
# repeat
all_size = self.total_size * self.world_size
indices = indices[:all_size]
num_repeat = (all_size - 1) // indices.shape[0] + 1
indices = np.tile(indices, num_repeat)
indices = indices[:all_size]
np.random.shuffle(indices)
# slice
beg = self.total_size * self.rank
indices = indices[beg:beg + self.total_size]
assert len(indices) == self.total_size
# set
self.indices = indices
def gen_new_list(self):
# each process shuffle all list with same seed, and pick one piece according to rank
np.random.seed(0)
all_size = self.total_size * self.world_size
indices = np.arange(len(self.dataset))
indices = indices[:all_size]
num_repeat = (all_size - 1) // indices.shape[0] + 1
indices = np.tile(indices, num_repeat)
indices = indices[:all_size]
np.random.shuffle(indices)
beg = self.total_size * self.rank
indices = indices[beg:beg + self.total_size]
assert len(indices) == self.total_size
return indices
def __len__(self):
# note here we do not take last iter into consideration, since __len__
# should only be used for displaying, the correct remaining size is
# handled by dataloader
# return self.total_size - (self.last_iter+1)*self.batch_size
return self.total_size
def set_epoch(self, epoch):
pass