voussoirkit/voussoirkit/downloady.py

492 lines
15 KiB
Python

import argparse
import os
import requests
import sys
import urllib
from voussoirkit import bytestring
from voussoirkit import dotdict
from voussoirkit import pathclass
from voussoirkit import pipeable
from voussoirkit import ratelimiter
from voussoirkit import vlogging
log = vlogging.getLogger(__name__, 'downloady')
USERAGENT = '''
'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko)
Chrome/42.0.2311.152 Safari/537.36'
'''.strip().replace('\n', ' ')
HEADERS = {
'User-Agent': USERAGENT,
}
FILENAME_BADCHARS = '*?"<>|\r\n'
CHUNKSIZE = 4 * bytestring.KIBIBYTE
TIMEOUT = 60
TEMP_EXTENSION = '.downloadytemp'
if os.name == 'nt':
SPECIAL_FILENAMES = pathclass.WINDOWS_RESERVED_NAMES
else:
SPECIAL_FILENAMES = [os.devnull]
SPECIAL_FILENAMES = [os.path.normcase(x) for x in SPECIAL_FILENAMES]
class DownloadyException(Exception):
pass
class NotEnoughBytes(DownloadyException):
pass
class ServerNoRange(DownloadyException):
pass
class SpecialPath:
def __init__(self, path):
self.absolute_path = path
def open(self, *args, **kwargs):
return open(self.absolute_path, *args, **kwargs)
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,
):
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):
if not isinstance(plan.download_into, SpecialPath):
plan.download_into.parent.makedirs(exist_ok=True)
plan.download_into.touch()
if plan.plan_type in ['resume', 'partial']:
file_handle = plan.download_into.open('r+b')
file_handle.seek(plan.seek_to)
bytes_downloaded = plan.seek_to
elif plan.plan_type == 'fulldownload':
file_handle = plan.download_into.open('wb')
bytes_downloaded = 0
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,
)
log.info('Downloading %s into "%s"', plan.url, plan.real_localname.absolute_path)
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 or other special names
if isinstance(plan.real_localname, SpecialPath):
return plan.real_localname
temp_localsize = plan.download_into.size
undersized = plan.plan_type != 'partial' and temp_localsize < plan.remote_total_bytes
if undersized and plan.raise_for_undersized:
message = 'File does not contain expected number of bytes. Received {size} / {total}'
message = message.format(size=temp_localsize, total=plan.remote_total_bytes)
raise NotEnoughBytes(message)
if plan.download_into != plan.real_localname:
os.rename(plan.download_into.absolute_path, plan.real_localname.absolute_path)
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
url = sanitize_url(url)
if localname in [None, '']:
localname = basename_from_url(url)
if is_special_file(localname):
real_localname = SpecialPath(localname)
temp_localname = SpecialPath(localname)
real_exists = False
temp_exists = False
else:
localname = pathclass.Path(localname)
if localname.is_dir:
localname = localname.with_child(basename_from_url(url))
localname = sanitize_filename(localname.absolute_path)
real_localname = pathclass.Path(localname)
temp_localname = real_localname.add_extension(TEMP_EXTENSION)
real_exists = real_localname.exists
temp_exists = temp_localname.exists
if real_exists and overwrite is False and not user_provided_range:
log.debug('File exists and overwrite is off. Nothing to do.')
return None
if isinstance(real_localname, SpecialPath):
temp_localsize = 0
else:
temp_localsize = int(temp_exists and temp_localname.size)
# 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
if user_provided_range and not do_head:
raise DownloadyException('Cannot determine range support without the head request')
temp_headers = headers.copy()
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:
raise ServerNoRange('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 = dotdict.DotDict(
plan_base,
download_into=temp_localname,
header_range_min=None,
header_range_max=None,
plan_type='fulldownload',
seek_to=0,
)
plan_resume = dotdict.DotDict(
plan_base,
download_into=temp_localname,
header_range_min=temp_localsize,
header_range_max='',
plan_type='resume',
seek_to=temp_localsize,
)
plan_partial = dotdict.DotDict(
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:
log.info('Resume from byte %d' % plan_resume.seek_to)
return plan_resume
else:
if user_provided_range:
return plan_partial
return plan_fulldownload
raise DownloadyException('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(1.00, percent)
if self.limiter.limit(1) is False and percent < 1.00:
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,
)
pipeable.stderr(message, end=end)
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 / self.total_bytes
percent = min(1.00, percent)
if self.limiter.limit(1) is False and percent < 1.00:
return
percent *= 100
percent_string = f'{percent:08.4f}'
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,
)
pipeable.stderr(message, end=end)
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.rsplit('/', 1)[-1]
return localname
def is_special_file(file):
if isinstance(file, pathclass.Path):
return False
file = pathclass.normalize_sep(file)
file = file.rsplit(os.sep)[-1]
file = os.path.normcase(file)
return file in SPECIAL_FILENAMES
def request(method, url, headers=None, timeout=TIMEOUT, verify_ssl=True, **kwargs):
if headers is None:
headers = {}
else:
headers = headers.copy()
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, headers=headers, timeout=timeout, verify=verify_ssl, **kwargs)
req.raise_for_status()
return req
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 download_argparse(args):
url = args.url
url = pipeable.input(url, split_lines=False)
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
@vlogging.main_decorator
def main(argv):
parser = argparse.ArgumentParser(description=__doc__)
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', 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:]))