view hgext/logtoprocess.py @ 40757:2f14d1bbc9a7

match: remove obsolete catching of OverflowError

Since 0f6a1bdf89fb (match: handle large regexes, 2007-08-19), we catch
an OverflowError from the regex engine and split up the regex if that
happens. In 59a9dc9562e2 (ignore: split up huge patterns, 2008-02-11),
that was extended to raise an OverflowError in our code even if the
regex engine doesn't raise it. It's unclear if there was a range of
regex sizes where the OverflowError would be raised from the regex
engine but that were still below the limit we added in our
code. Either way, both limitations were probably removed in Python
2.7.4 when the regex code width was extended from 16bit to 32bit (or
Py_UCS4) integer (thanks to Yuya for finding that out).

If at least the first limitation was removed, we no longer should be
using OverflowError for flow control, so this patch changes that.

Differential Revision: https://phab.mercurial-scm.org/D5309

# 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 import (
    pycompat,
)
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 = '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[0] % msg[1:],
        }
        # keyword arguments get prefixed with OPT_ and uppercased
        env.update((b'OPT_%s' % key.upper(), value)
                   for key, value in pycompat.byteskwargs(opts).items())
        fullenv = procutil.shellenviron(env)
        procutil.runbgcommand(script, fullenv, shell=True)

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