hgext/logtoprocess.py

subrepo: fix a crash when archiving an svn or git subrepo

Only hgsubrepos have a repository attribute.  This is pretty hacky, but probably
the best we can do on stable.  Pushing the lfstatus check down into the wrapper
for hgsubrepo (and dropping the check for lfstatus at the top of
`hgsubrepoarchive()`) resulted in various test failures because:

  1) hgsubrepoarchive isn't returning the number of files archived at the
     bottom, resulting in an error about += NoneType
  2) These copypasta archive wrappers don't use progress bars
  3) Largefiles are *not* currently archived when using extdiff (68822b7cdd01),
     but pushing this context manager down into the subrepo resulted in it
     apparently doing so (as evidenced by progress bars being dropped)

The other uses of `lfstatus()` are not in the substate processing loop, so they
shouldn't be an issue.

I initially put testcases in this test for largefiles-{on,off}, and it flagged
a bunch of exit code differences for `cat` and `diff`, so I backed that off.

Differential Revision: https://phab.mercurial-scm.org/D7714

# 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.

Positional arguments construct a log message, which is passed in the `MSG1`
environment variables. 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 %s\n', 'baz', spam='eggs'), a script
configured for the `foo` event can expect an environment with `MSG1=bar baz`,
and `OPT_SPAM=eggs`.

Scripts are configured in the `[logtoprocess]` section, each key an event name.
For example::

  [logtoprocess]
  commandexception = echo "$MSG1" > /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 os

from mercurial.utils import procutil

# 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 = b'ships-with-hg-core'


class processlogger(object):
    """Map log events to external commands

    Arguments are passed on as environment variables.
    """

    def __init__(self, ui):
        self._scripts = dict(ui.configitems(b'logtoprocess'))

    def tracked(self, event):
        return bool(self._scripts.get(event))

    def log(self, ui, event, msg, opts):
        script = self._scripts[event]
        env = {
            b'EVENT': event,
            b'HGPID': os.getpid(),
            b'MSG1': msg,
        }
        # keyword arguments get prefixed with OPT_ and uppercased
        env.update(
            (b'OPT_%s' % key.upper(), value) for key, value in opts.items()
        )
        fullenv = procutil.shellenviron(env)
        procutil.runbgcommand(script, fullenv, shell=True)


def uipopulate(ui):
    ui.setlogger(b'logtoprocess', processlogger(ui))