mammography-plugin/download.py

77 lines
2.6 KiB
Python

# Orthanc plugin for mammography
# Copyright (C) 2024 Edouard Chatzopoulos and Sebastien Jodogne,
# ICTEAM UCLouvain, Belgium
#
# This program is free software: you can redistribute it and/or
# modify it under the terms of the GNU Affero General Public License
# as published by the Free Software Foundation, either version 3 of
# the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
import hashlib
import io
import os
import requests
import sys
def get(target, url, expected_size, expected_md5):
print('Downloading: %s' % url)
if os.path.isfile(target):
with open(target, 'rb') as f:
content = f.read()
if (len(content) == expected_size and
hashlib.md5(content).hexdigest() == expected_md5):
print(' File already downloaded')
return
else:
raise Exception('Target file already exists with bad content, please remove it: %s' % target)
r = requests.get(url, stream = True)
r.raise_for_status()
content_length = int(r.headers['Content-Length'])
if content_length != expected_size:
raise Exception('Bad file size on the server: %d (actual) vs. %d (expected)' % (content_length, expected_size))
bar_width = 30
with io.BytesIO() as f:
progress = 0
for chunk in r.iter_content(chunk_size = 1024 * 1024):
f.write(chunk)
progress += len(chunk)
percent = float(progress) / float(content_length)
sys.stdout.write('\r')
sys.stdout.write(' Completed: [{:{}}] {:>3}%'
.format('=' * round(percent * float(bar_width)),
bar_width, round(percent * 100.0)))
sys.stdout.flush()
sys.stdout.write('\n')
sys.stdout.flush()
f.seek(0)
content = f.read()
if len(content) != expected_size:
raise Exception('Server has not returned the expected number of bytes: %d (actual) vs. %d (expected)' % (len(content), expected_size))
actual_md5 = hashlib.md5(content).hexdigest()
if actual_md5 != expected_md5:
raise Exception('Bad MD5 checksum: %s (actual) vs. %s (expected)' % (actual_md5, expected_md5))
with open(target, 'wb') as f:
f.write(content)