mmclassification/mmcls/datasets/utils.py

154 lines
4.4 KiB
Python

# Copyright (c) OpenMMLab. All rights reserved.
import gzip
import hashlib
import os
import os.path
import shutil
import tarfile
import urllib.error
import urllib.request
import zipfile
__all__ = ['rm_suffix', 'check_integrity', 'download_and_extract_archive']
def rm_suffix(s, suffix=None):
if suffix is None:
return s[:s.rfind('.')]
else:
return s[:s.rfind(suffix)]
def calculate_md5(fpath, chunk_size=1024 * 1024):
md5 = hashlib.md5()
with open(fpath, 'rb') as f:
for chunk in iter(lambda: f.read(chunk_size), b''):
md5.update(chunk)
return md5.hexdigest()
def check_md5(fpath, md5, **kwargs):
return md5 == calculate_md5(fpath, **kwargs)
def check_integrity(fpath, md5=None):
if not os.path.isfile(fpath):
return False
if md5 is None:
return True
return check_md5(fpath, md5)
def download_url_to_file(url, fpath):
with urllib.request.urlopen(url) as resp, open(fpath, 'wb') as of:
shutil.copyfileobj(resp, of)
def download_url(url, root, filename=None, md5=None):
"""Download a file from a url and place it in root.
Args:
url (str): URL to download file from.
root (str): Directory to place downloaded file in.
filename (str | None): Name to save the file under.
If filename is None, use the basename of the URL.
md5 (str | None): MD5 checksum of the download.
If md5 is None, download without md5 check.
"""
root = os.path.expanduser(root)
if not filename:
filename = os.path.basename(url)
fpath = os.path.join(root, filename)
os.makedirs(root, exist_ok=True)
if check_integrity(fpath, md5):
print(f'Using downloaded and verified file: {fpath}')
else:
try:
print(f'Downloading {url} to {fpath}')
download_url_to_file(url, fpath)
except (urllib.error.URLError, IOError) as e:
if url[:5] == 'https':
url = url.replace('https:', 'http:')
print('Failed download. Trying https -> http instead.'
f' Downloading {url} to {fpath}')
download_url_to_file(url, fpath)
else:
raise e
# check integrity of downloaded file
if not check_integrity(fpath, md5):
raise RuntimeError('File not found or corrupted.')
def _is_tarxz(filename):
return filename.endswith('.tar.xz')
def _is_tar(filename):
return filename.endswith('.tar')
def _is_targz(filename):
return filename.endswith('.tar.gz')
def _is_tgz(filename):
return filename.endswith('.tgz')
def _is_gzip(filename):
return filename.endswith('.gz') and not filename.endswith('.tar.gz')
def _is_zip(filename):
return filename.endswith('.zip')
def extract_archive(from_path, to_path=None, remove_finished=False):
if to_path is None:
to_path = os.path.dirname(from_path)
if _is_tar(from_path):
with tarfile.open(from_path, 'r') as tar:
tar.extractall(path=to_path)
elif _is_targz(from_path) or _is_tgz(from_path):
with tarfile.open(from_path, 'r:gz') as tar:
tar.extractall(path=to_path)
elif _is_tarxz(from_path):
with tarfile.open(from_path, 'r:xz') as tar:
tar.extractall(path=to_path)
elif _is_gzip(from_path):
to_path = os.path.join(
to_path,
os.path.splitext(os.path.basename(from_path))[0])
with open(to_path, 'wb') as out_f, gzip.GzipFile(from_path) as zip_f:
out_f.write(zip_f.read())
elif _is_zip(from_path):
with zipfile.ZipFile(from_path, 'r') as z:
z.extractall(to_path)
else:
raise ValueError(f'Extraction of {from_path} not supported')
if remove_finished:
os.remove(from_path)
def download_and_extract_archive(url,
download_root,
extract_root=None,
filename=None,
md5=None,
remove_finished=False):
download_root = os.path.expanduser(download_root)
if extract_root is None:
extract_root = download_root
if not filename:
filename = os.path.basename(url)
download_url(url, download_root, filename, md5)
archive = os.path.join(download_root, filename)
print(f'Extracting {archive} to {extract_root}')
extract_archive(archive, extract_root, remove_finished)