Mercurial > hg
view hgext/logtoprocess.py @ 31395:361bccce566a
rebase: don't use mutable default argument value
author | Gregory Szorc <gregory.szorc@gmail.com> |
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date | Sun, 12 Mar 2017 21:56:39 -0700 |
parents | 1c5cbf28f007 |
children | 8e7feaad2d8d |
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# logtoprocess.py - send ui.log() data to a subprocess # # Copyright 2016 Facebook, Inc. # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """Send ui.log() data to a subprocess (EXPERIMENTAL) This extension lets you specify a shell command per ui.log() event, sending all remaining arguments to as environment variables to that command. Each positional argument to the method results in a `MSG[N]` key in the environment, starting at 1 (so `MSG1`, `MSG2`, etc.). Each keyword argument is set as a `OPT_UPPERCASE_KEY` variable (so the key is uppercased, and prefixed with `OPT_`). The original event name is passed in the `EVENT` environment variable, and the process ID of mercurial is given in `HGPID`. So given a call `ui.log('foo', 'bar', 'baz', spam='eggs'), a script configured for the `foo` event can expect an environment with `MSG1=bar`, `MSG2=baz`, and `OPT_SPAM=eggs`. Scripts are configured in the `[logtoprocess]` section, each key an event name. For example:: [logtoprocess] commandexception = echo "$MSG2$MSG3" > /var/log/mercurial_exceptions.log would log the warning message and traceback of any failed command dispatch. Scripts are run asynchronously as detached daemon processes; mercurial will not ensure that they exit cleanly. """ from __future__ import absolute_import import itertools import os import platform import subprocess import sys from mercurial import encoding # Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for # extensions which SHIP WITH MERCURIAL. Non-mainline extensions should # be specifying the version(s) of Mercurial they are tested with, or # leave the attribute unspecified. testedwith = 'ships-with-hg-core' def uisetup(ui): if platform.system() == 'Windows': # no fork on Windows, but we can create a detached process # https://msdn.microsoft.com/en-us/library/windows/desktop/ms684863.aspx # No stdlib constant exists for this value DETACHED_PROCESS = 0x00000008 _creationflags = DETACHED_PROCESS | subprocess.CREATE_NEW_PROCESS_GROUP def runshellcommand(script, env): # we can't use close_fds *and* redirect stdin. I'm not sure that we # need to because the detached process has no console connection. subprocess.Popen( script, shell=True, env=env, close_fds=True, creationflags=_creationflags) else: def runshellcommand(script, env): # double-fork to completely detach from the parent process # based on http://code.activestate.com/recipes/278731 pid = os.fork() if pid: # parent return # subprocess.Popen() forks again, all we need to add is # flag the new process as a new session. if sys.version_info < (3, 2): newsession = {'preexec_fn': os.setsid} else: newsession = {'start_new_session': True} try: # connect stdin to devnull to make sure the subprocess can't # muck up that stream for mercurial. subprocess.Popen( script, shell=True, stdin=open(os.devnull, 'r'), env=env, close_fds=True, **newsession) finally: # mission accomplished, this child needs to exit and not # continue the hg process here. os._exit(0) class logtoprocessui(ui.__class__): def log(self, event, *msg, **opts): """Map log events to external commands Arguments are passed on as environment variables. """ script = self.config('logtoprocess', event) if script: if msg: # try to format the log message given the remaining # arguments try: # Python string formatting with % either uses a # dictionary *or* tuple, but not both. If we have # keyword options, assume we need a mapping. formatted = msg[0] % (opts or msg[1:]) except (TypeError, KeyError): # Failed to apply the arguments, ignore formatted = msg[0] messages = (formatted,) + msg[1:] else: messages = msg # positional arguments are listed as MSG[N] keys in the # environment msgpairs = ( ('MSG{0:d}'.format(i), str(m)) for i, m in enumerate(messages, 1)) # keyword arguments get prefixed with OPT_ and uppercased optpairs = ( ('OPT_{0}'.format(key.upper()), str(value)) for key, value in opts.iteritems()) env = dict(itertools.chain(encoding.environ.items(), msgpairs, optpairs), EVENT=event, HGPID=str(os.getpid())) # Connect stdin to /dev/null to prevent child processes messing # with mercurial's stdin. runshellcommand(script, env) return super(logtoprocessui, self).log(event, *msg, **opts) # Replace the class for this instance and all clones created from it: ui.__class__ = logtoprocessui