voussoirkit/voussoirkit/downloady.py
2020-02-25 10:39:30 -08:00

466 lines
14 KiB
Python

import argparse
import os
import requests
import sys
import urllib
import warnings
from voussoirkit import bytestring
from voussoirkit import ratelimiter
from voussoirkit import clipext
warnings.simplefilter('ignore')
HEADERS = {
'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.152 Safari/537.36'
}
FILENAME_BADCHARS = '*?"<>|\r\n'
last_request = 0
CHUNKSIZE = 4 * bytestring.KIBIBYTE
TIMEOUT = 60
TEMP_EXTENSION = '.downloadytemp'
PRINT_LIMITER = ratelimiter.Ratelimiter(allowance=5, mode='reject')
class NotEnoughBytes(Exception):
pass
def download_file(
url,
localname=None,
auth=None,
bytespersecond=None,
callback_progress=None,
do_head=True,
headers=None,
overwrite=False,
raise_for_undersized=True,
timeout=None,
verbose=False,
verify_ssl=True,
):
headers = headers or {}
url = sanitize_url(url)
if localname in [None, '']:
localname = basename_from_url(url)
if os.path.isdir(localname):
localname = os.path.join(localname, basename_from_url(url))
localname = sanitize_filename(localname)
if localname != os.devnull:
localname = os.path.abspath(localname)
if verbose:
safeprint(' URL:', url)
safeprint('File:', localname)
plan = prepare_plan(
url,
localname,
auth=auth,
bytespersecond=bytespersecond,
callback_progress=callback_progress,
do_head=do_head,
headers=headers,
overwrite=overwrite,
raise_for_undersized=raise_for_undersized,
timeout=timeout,
verify_ssl=verify_ssl,
)
if plan is None:
return
return download_plan(plan)
def download_plan(plan):
localname = plan['download_into']
directory = os.path.split(localname)[0]
if directory != '':
os.makedirs(directory, exist_ok=True)
touch(localname)
file_handle = open(localname, 'r+b')
file_handle.seek(plan['seek_to'])
if plan['header_range_min'] is not None:
plan['headers']['range'] = 'bytes={min}-{max}'.format(
min=plan['header_range_min'],
max=plan['header_range_max'],
)
if plan['plan_type'] == 'resume':
bytes_downloaded = plan['seek_to']
elif plan['plan_type'] == 'partial':
bytes_downloaded = plan['seek_to']
else:
bytes_downloaded = 0
download_stream = request(
'get',
plan['url'],
stream=True,
auth=plan['auth'],
headers=plan['headers'],
timeout=plan['timeout'],
verify_ssl=plan['verify_ssl'],
)
if plan['remote_total_bytes'] is None:
# Since we didn't do a head, let's fill this in now.
plan['remote_total_bytes'] = int(download_stream.headers.get('Content-Length', 0))
callback_progress = plan['callback_progress']
if callback_progress is not None:
callback_progress = callback_progress(plan['remote_total_bytes'])
for chunk in download_stream.iter_content(chunk_size=CHUNKSIZE):
bytes_downloaded += len(chunk)
file_handle.write(chunk)
if callback_progress is not None:
callback_progress.step(bytes_downloaded)
if plan['limiter'] is not None and bytes_downloaded < plan['remote_total_bytes']:
plan['limiter'].limit(len(chunk))
file_handle.close()
# Don't try to rename /dev/null
if os.devnull not in [localname, plan['real_localname']]:
localsize = os.path.getsize(localname)
undersized = plan['plan_type'] != 'partial' and localsize < plan['remote_total_bytes']
if plan['raise_for_undersized'] and undersized:
message = 'File does not contain expected number of bytes. Received {size} / {total}'
message = message.format(size=localsize, total=plan['remote_total_bytes'])
raise NotEnoughBytes(message)
if localname != plan['real_localname']:
os.rename(localname, plan['real_localname'])
return plan['real_localname']
def prepare_plan(
url,
localname,
auth=None,
bytespersecond=None,
callback_progress=None,
do_head=True,
headers=None,
overwrite=False,
raise_for_undersized=True,
timeout=TIMEOUT,
verify_ssl=True,
):
# Chapter 1: File existence
headers = headers or {}
user_provided_range = 'range' in headers
real_localname = localname
temp_localname = localname + TEMP_EXTENSION
real_exists = os.path.exists(real_localname)
if real_exists and overwrite is False and not user_provided_range:
print('File exists and overwrite is off. Nothing to do.')
return None
temp_exists = os.path.exists(temp_localname)
real_localsize = int(real_exists and os.path.getsize(real_localname))
temp_localsize = int(temp_exists and os.path.getsize(temp_localname))
# Chapter 2: Ratelimiting
if bytespersecond is None:
limiter = None
elif isinstance(bytespersecond, ratelimiter.Ratelimiter):
limiter = bytespersecond
else:
limiter = ratelimiter.Ratelimiter(allowance=bytespersecond)
# Chapter 3: Extracting range
if user_provided_range:
user_range_min = int(headers['range'].split('bytes=')[1].split('-')[0])
user_range_max = headers['range'].split('-')[1]
if user_range_max != '':
user_range_max = int(user_range_max)
else:
user_range_min = None
user_range_max = None
# Chapter 4: Server range support
# Always include a range on the first request to figure out whether the
# server supports it. Use 0- to get correct remote_total_bytes
temp_headers = headers
temp_headers.update({'range': 'bytes=0-'})
if do_head:
# I'm using a GET instead of an actual HEAD here because some servers respond
# differently, even though they're not supposed to.
head = request('get', url, stream=True, headers=temp_headers, auth=auth)
remote_total_bytes = int(head.headers.get('content-length', 0))
server_respects_range = (head.status_code == 206 and 'content-range' in head.headers)
head.connection.close()
else:
remote_total_bytes = None
server_respects_range = False
if user_provided_range and not server_respects_range:
if not do_head:
raise Exception('Cannot determine range support without the head request')
else:
raise Exception('Server did not respect your range header')
# Chapter 5: Plan definitions
plan_base = {
'url': url,
'auth': auth,
'callback_progress': callback_progress,
'limiter': limiter,
'headers': headers,
'real_localname': real_localname,
'raise_for_undersized': raise_for_undersized,
'remote_total_bytes': remote_total_bytes,
'timeout': timeout,
'verify_ssl': verify_ssl,
}
plan_fulldownload = dict(
plan_base,
download_into=temp_localname,
header_range_min=None,
header_range_max=None,
plan_type='fulldownload',
seek_to=0,
)
plan_resume = dict(
plan_base,
download_into=temp_localname,
header_range_min=temp_localsize,
header_range_max='',
plan_type='resume',
seek_to=temp_localsize,
)
plan_partial = dict(
plan_base,
download_into=real_localname,
header_range_min=user_range_min,
header_range_max=user_range_max,
plan_type='partial',
seek_to=user_range_min,
)
# Chapter 6: Redeem your meal vouchers here
if real_exists:
if overwrite:
os.remove(real_localname)
if user_provided_range:
return plan_partial
return plan_fulldownload
elif temp_exists and temp_localsize > 0:
if overwrite:
return plan_fulldownload
if user_provided_range:
return plan_partial
if server_respects_range:
print('Resume from byte %d' % plan_resume['seek_to'])
return plan_resume
else:
if user_provided_range:
return plan_partial
return plan_fulldownload
raise Exception('No plan was chosen?')
class Progress1:
def __init__(self, total_bytes):
self.limiter = ratelimiter.Ratelimiter(allowance=8, mode='reject')
self.limiter.balance = 1
self.total_bytes = max(1, total_bytes)
self.divisor = bytestring.get_appropriate_divisor(total_bytes)
self.total_format = bytestring.bytestring(total_bytes, force_unit=self.divisor)
self.downloaded_format = '{:>%d}' % len(self.total_format)
self.blank_char = ' '
self.solid_char = ''
def step(self, bytes_downloaded):
percent = bytes_downloaded / self.total_bytes
percent = min(1, percent)
if self.limiter.limit(1) is False and percent < 1:
return
downloaded_string = bytestring.bytestring(bytes_downloaded, force_unit=self.divisor)
downloaded_string = self.downloaded_format.format(downloaded_string)
block_count = 50
solid_blocks = self.solid_char * int(block_count * percent)
statusbar = solid_blocks.ljust(block_count, self.blank_char)
statusbar = self.solid_char + statusbar + self.solid_char
end = '\n' if percent == 1 else ''
message = '\r{bytes_downloaded} {statusbar} {total_bytes}'
message = message.format(
bytes_downloaded=downloaded_string,
total_bytes=self.total_format,
statusbar=statusbar,
)
print(message, end=end, flush=True)
class Progress2:
def __init__(self, total_bytes):
self.total_bytes = max(1, total_bytes)
self.limiter = ratelimiter.Ratelimiter(allowance=8, mode='reject')
self.limiter.balance = 1
self.total_bytes_string = '{:,}'.format(self.total_bytes)
self.bytes_downloaded_string = '{:%d,}' % len(self.total_bytes_string)
def step(self, bytes_downloaded):
percent = (bytes_downloaded * 100) / self.total_bytes
percent = min(100, percent)
if self.limiter.limit(1) is False and percent < 100:
return
percent_string = '%08.4f' % percent
bytes_downloaded_string = self.bytes_downloaded_string.format(bytes_downloaded)
end = '\n' if percent == 100 else ''
message = '\r{bytes_downloaded} / {total_bytes} / {percent}%'
message = message.format(
bytes_downloaded=bytes_downloaded_string,
total_bytes=self.total_bytes_string,
percent=percent_string,
)
print(message, end=end, flush=True)
def basename_from_url(url):
'''
Determine the local filename appropriate for a URL.
'''
localname = urllib.parse.unquote(url)
localname = localname.rstrip('/')
localname = localname.split('?')[0]
localname = localname.split('/')[-1]
return localname
def get_permission(prompt='y/n\n>', affirmative=['y', 'yes']):
permission = input(prompt)
return permission.lower() in affirmative
def request(method, url, stream=False, headers=None, timeout=TIMEOUT, verify_ssl=True, **kwargs):
if headers is None:
headers = {}
for (key, value) in HEADERS.items():
headers.setdefault(key, value)
session = requests.Session()
a = requests.adapters.HTTPAdapter(max_retries=30)
b = requests.adapters.HTTPAdapter(max_retries=30)
session.mount('http://', a)
session.mount('https://', b)
session.max_redirects = 40
method = {
'get': session.get,
'head': session.head,
'post': session.post,
}[method]
req = method(url, stream=stream, headers=headers, timeout=timeout, verify=verify_ssl, **kwargs)
req.raise_for_status()
return req
def safeprint(*texts, **kwargs):
texts = [str(text).encode('ascii', 'replace').decode() for text in texts]
print(*texts, **kwargs)
def sanitize_filename(text, exclusions=''):
to_remove = FILENAME_BADCHARS
for exclude in exclusions:
to_remove = to_remove.replace(exclude, '')
for char in to_remove:
text = text.replace(char, '')
(drive, path) = os.path.splitdrive(text)
path = path.replace(':', '')
text = drive + path
return text
def sanitize_url(url):
url = url.replace('%3A//', '://')
return url
def touch(filename):
f = open(filename, 'ab')
f.close()
return
def download_argparse(args):
url = args.url
url = clipext.resolve(url)
callback = {
None: Progress1,
'1': Progress1,
'2': Progress2,
}.get(args.callback, args.callback)
bytespersecond = args.bytespersecond
if bytespersecond is not None:
bytespersecond = bytestring.parsebytes(bytespersecond)
headers = {}
if args.range is not None:
headers['range'] = 'bytes=%s' % args.range
retry = args.retry
if not retry:
retry = 1
while retry != 0:
# Negative numbers permit infinite retries.
try:
download_file(
url=url,
localname=args.localname,
bytespersecond=bytespersecond,
callback_progress=callback,
do_head=args.no_head is False,
headers=headers,
overwrite=args.overwrite,
timeout=args.timeout,
verbose=True,
verify_ssl=args.no_ssl is False,
)
except (NotEnoughBytes, requests.exceptions.ConnectionError, requests.exceptions.ChunkedEncodingError):
retry -= 1
if retry == 0:
raise
else:
break
def main(argv):
parser = argparse.ArgumentParser()
parser.add_argument('url')
parser.add_argument('localname', nargs='?', default=None)
parser.add_argument('-c', '--callback', dest='callback', default=Progress1)
parser.add_argument('-bps', '--bytespersecond', dest='bytespersecond', default=None)
parser.add_argument('-ow', '--overwrite', dest='overwrite', action='store_true')
parser.add_argument('-r', '--range', dest='range', default=None)
parser.add_argument('--timeout', dest='timeout', type=int, default=TIMEOUT)
parser.add_argument('--retry', dest='retry', const=-1, nargs='?', type=int, default=1)
parser.add_argument('--no-head', dest='no_head', action='store_true')
parser.add_argument('--no-ssl', dest='no_ssl', action='store_true')
parser.set_defaults(func=download_argparse)
args = parser.parse_args(argv)
return args.func(args)
if __name__ == '__main__':
raise SystemExit(main(sys.argv[1:]))