cmd/q.py

313 lines
9.4 KiB
Python

import argparse
import hashlib
import os
import re
import sys
import time
import traceback
# make this on your pythonpath like this:
# EXTENSION_COMMANDS = {
# 'ytqueue': ('youtube-dl', '{id}'),
# }
import qcommands
from voussoirkit import backoff
from voussoirkit import betterhelp
from voussoirkit import dotdict
from voussoirkit import operatornotify
from voussoirkit import pathclass
from voussoirkit import vlogging
log = vlogging.getLogger(__name__, 'q')
# When no more queuefiles are discovered, the program will sleep for increasing
# amounts of time to reduce the amount of disk activity.
sleeping_backoff = backoff.Linear(m=1, b=10, max=600)
# Each file gets an individual backoff object when it encounters an error, so
# we can continue processing other files while and come back to the problematic
# ones later, with increasing timeouts.
error_backoffs = {}
# If a file demonstrates unrecoverable errors, we blacklist it and never touch
# it again. If the file ever disappears then we remove it from the blacklist.
error_blacklist = set()
def filter_collaborate(files, collaborate):
if collaborate is None:
return files
newfiles = []
for file in files:
bits = int(hashlib.md5(file.basename.encode('utf-8')).hexdigest(), 16)
if ((bits % collaborate.mod) + 1) == collaborate.mine:
newfiles.append(file)
return newfiles
def get_extension_command(extension):
for (key, (command, argument)) in qcommands.EXTENSION_COMMANDS.items():
if isinstance(key, str):
if key == extension:
return (command, argument)
continue
match = re.match(key, extension)
if not match:
continue
groups = match.groups()
if not groups:
return (command, argument)
command = re.sub(key, command, extension)
return (command, argument)
def handle_blacklist(file, reason=''):
if reason:
log.warning('%s is blacklisted because:\n%s', file.absolute_path, reason)
else:
log.warning('%s is blacklisted.', file.absolute_path)
error_blacklist.add(file)
def handle_failure(file):
err_bo = error_backoffs.get(file)
if err_bo is None:
err_bo = backoff.Linear(m=3600, b=3600, max=86400)
error_backoffs[file] = err_bo
if (err_bo.x % 3) == 1:
log.warning('%s is having repeated problems.', file.absolute_path)
timeout = err_bo.next()
log.info('%s is in time out for %d.', file.absolute_path, timeout)
err_bo.expire_at = time.time() + timeout
def override_extension_commands(extension, command):
extension = extension.lower().strip('.')
print(command)
if command:
command = [f'"{x}"' if ' ' in x else x for x in command]
command = ' '.join(command).strip()
else:
command = qcommands.EXTENSION_COMMANDS[extension]
qcommands.EXTENSION_COMMANDS.clear()
qcommands.EXTENSION_COMMANDS[extension] = (command, '{id}')
def parse_collaborate(collaborate):
if collaborate is None:
return None
collaborate = collaborate.strip()
if not collaborate:
return None
(mod, mine) = collaborate.split('.')
if mod == 1:
return None
mod = int(mod)
mine = int(mine)
if mine == 0:
raise ValueError('Collaborate values are 1-indexed, don\'t use 0.')
collaborate = dotdict.DotDict(mod=mod, mine=mine)
return collaborate
def process_file(file, args=None):
# Race condition
if not file.exists:
return
if file in error_blacklist:
return
err_bo = error_backoffs.get(file)
if err_bo is not None and time.time() < err_bo.expire_at:
return
extension = file.extension.no_dot.lower()
if not get_extension_command(extension):
return
############################################################################
sleeping_backoff.reset()
commands = []
if file.size > 0:
links = read_file_links(file)
(command, argument) = get_extension_command(extension)
commands.extend(f'{command} "{link}"' for link in links)
else:
(command, argument) = get_extension_command(extension)
base = file.replace_extension('').basename
argument = argument.format(id=base)
commands.append(f'{command} {argument}')
exit_code = 0
for command in commands:
log.info(f'Handling {file.basename} with `{command}`')
exit_code = os.system(command)
if exit_code != 0:
handle_failure(file)
break
if exit_code == 0:
try:
os.remove(file)
except FileNotFoundError:
# Race condition
pass
except PermissionError:
handle_blacklist(file, reason=traceback.format_exc())
def prune_blacklist():
if not error_blacklist:
return
for file in list(error_blacklist):
if not file.exists:
error_blacklist.remove(file)
def prune_error_backoffs():
if not error_backoffs:
return
now = time.time()
for (file, err_bo) in list(error_backoffs.items()):
if not file.exists:
error_backoffs.pop(file)
continue
def read_file_links(file):
links = file.open('r').read().splitlines()
links = (l.strip() for l in links)
links = (l for l in links if l)
links = (l for l in links if not l.startswith('#'))
return links
def queue_once(folders, collaborate=None):
log.info(time.strftime('%H:%M:%S Looking for files.'))
files = []
for folder in folders:
try:
files.extend(folder.listdir_files())
except Exception as exc:
log.warning('listdir %s raised:\ntraceback.format_exc()', folder)
files = filter_collaborate(files, collaborate)
for file in files:
process_file(file)
prune_error_backoffs()
prune_blacklist()
def queue_forever(folders, collaborate=None):
while True:
queue_once(folders, collaborate=collaborate)
time.sleep(sleeping_backoff.next())
def q_argparse(args):
if args.extension:
override_extension_commands(args.extension, args.command)
if args.folders:
folders = [pathclass.Path(d) for d in args.folders]
else:
folders = [pathclass.cwd()]
for folder in folders:
folder.assert_is_directory()
if args.once:
queue_once(folders=folders)
return 0
try:
queue_forever(folders=folders, collaborate=args.collaborate)
except KeyboardInterrupt:
return 0
@operatornotify.main_decorator(subject='q.py', notify_every_line=True)
@vlogging.main_decorator
def main(argv):
parser = argparse.ArgumentParser(description='''
This program is used to process so-called "queuefiles".
The queuefile is a file where the extension indicates what command
should be used to handle it, and the command's argument is either the
file's name, or the content of the file.
If the queuefile is zero bytes, then the name of the file is the
argument to the command. If the file is non-empty, then the contents
are read as lines, and the command is invoked once for each line as
an argument.
For example, 0123456789a.youtube could be a zero-byte queuefile
that will be handled by youtube-dl to download the youtube video
with 0123456789a.
On the other hand, 012345789.wayback could be a queuefile that contains
an HTTP link inside, and the command will post it to web.archive.org.
''')
parser.add_argument(
'extension',
nargs='?',
default=None,
help='''
Process only queuefiles with this particular extension. Leave blank
to process all recognized extensions.
''',
)
parser.add_argument(
'command',
nargs='*',
default=None,
)
parser.add_argument('--folders', nargs='*', default=None)
parser.add_argument(
'--once',
dest='once',
action='store_true',
help='''
Process queuefiles until there are none left, then stop the program.
''',
)
parser.add_argument(
'--collaborate',
dest='collaborate',
default=None,
type=parse_collaborate,
metavar='mod.mine',
help='''
Due to youtube download throttling, I want to run multiple q processes
to download multiple videos simultaneously, but I don't necessarily want to
deal with multiprocess management within this program because each process
makes lots of console output. So the idea is that we run multiple copies of
this file with different --collaborate settings and they collaboratively
partition the files amongst themselves. Another way of doing this is to put
the queuefiles into separate folders and run one process per folder, but
that puts the burden on the side that creates the queuefiles.
The way this argument works is two numbers separated by a period: `mod.mine`.
All of the q processes should have the same number for `mod`, and each
process should have a different number for `mine`, counting 1, 2, 3,
until mod.
If you want to collaborate with three processes, you'd use
--collaborate 3.1 for one instance, --collaborate 3.2 for the second, and
--collaborate 3.3 for the third.
''',
)
parser.set_defaults(func=q_argparse)
return betterhelp.go(parser, argv)
if __name__ == '__main__':
raise SystemExit(main(sys.argv[1:]))