httpie-cli/httpie/internal/daemons.py
SADIK KUZU 542a2d35de
Fix typos in comment lines (#1405)
* httpie/internal/daemons.py
* httpie/utils.py
2022-05-19 16:22:50 +03:00

122 lines
3.3 KiB
Python

"""
This module provides an interface to spawn a detached task to be
run with httpie.internal.daemon_runner on a separate process. It is
based on DVC's daemon system.
https://github.com/iterative/dvc/blob/main/dvc/daemon.py
"""
import inspect
import os
import platform
import sys
import httpie.__main__
from contextlib import suppress
from subprocess import Popen, DEVNULL
from typing import Dict, List
from httpie.compat import is_frozen, is_windows
ProcessContext = Dict[str, str]
def _start_process(cmd: List[str], **kwargs) -> Popen:
prefix = [sys.executable]
# If it is frozen, sys.executable points to the binary (http).
# Otherwise it points to the python interpreter.
if not is_frozen:
main_entrypoint = httpie.__main__.__file__
prefix += [main_entrypoint]
return Popen(prefix + cmd, close_fds=True, shell=False, stdout=DEVNULL, stderr=DEVNULL, **kwargs)
def _spawn_windows(cmd: List[str], process_context: ProcessContext) -> None:
from subprocess import (
CREATE_NEW_PROCESS_GROUP,
CREATE_NO_WINDOW,
STARTF_USESHOWWINDOW,
STARTUPINFO,
)
# https://stackoverflow.com/a/7006424
# https://bugs.python.org/issue41619
creationflags = CREATE_NEW_PROCESS_GROUP | CREATE_NO_WINDOW
startupinfo = STARTUPINFO()
startupinfo.dwFlags |= STARTF_USESHOWWINDOW
_start_process(
cmd,
env=process_context,
creationflags=creationflags,
startupinfo=startupinfo,
)
def _spawn_posix(args: List[str], process_context: ProcessContext) -> None:
"""
Perform a double fork procedure* to detach from the parent
process so that we don't block the user even if their original
command's execution is done but the release fetcher is not.
[1]: https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap11.html#tag_11_01_03
"""
from httpie.core import main
try:
pid = os.fork()
if pid > 0:
return
except OSError:
os._exit(1)
os.setsid()
try:
pid = os.fork()
if pid > 0:
os._exit(0)
except OSError:
os._exit(1)
# Close all standard inputs/outputs
sys.stdin.close()
sys.stdout.close()
sys.stderr.close()
if platform.system() == 'Darwin':
# Double-fork is not reliable on MacOS, so we'll use a subprocess
# to ensure the task is isolated properly.
process = _start_process(args, env=process_context)
# Unlike windows, since we already completed the fork procedure
# we can simply join the process and wait for it.
process.communicate()
else:
os.environ.update(process_context)
with suppress(BaseException):
main(['http'] + args)
os._exit(0)
def _spawn(args: List[str], process_context: ProcessContext) -> None:
"""
Spawn a new process to run the given command.
"""
if is_windows:
_spawn_windows(args, process_context)
else:
_spawn_posix(args, process_context)
def spawn_daemon(task: str) -> None:
args = [task, '--daemon']
process_context = os.environ.copy()
if not is_frozen:
file_path = os.path.abspath(inspect.stack()[0][1])
process_context['PYTHONPATH'] = os.path.dirname(
os.path.dirname(os.path.dirname(file_path))
)
_spawn(args, process_context)