Mercurial > hg
view mercurial/scmposix.py @ 31956:c13ff31818b0
ui: add special-purpose atexit functionality
In spite of its longstanding use, Python's built-in atexit code is
not suitable for Mercurial's purposes, for several reasons:
* Handlers run after application code has finished.
* Because of this, the code that runs handlers swallows exceptions
(since there's no possible stacktrace to associate errors with).
If we're lucky, we'll get something spat out to stderr (if stderr
still works), which of course isn't any use in a big deployment
where it's important that exceptions get logged and aggregated.
* Mercurial's current atexit handlers make unfortunate assumptions
about process state (specifically stdio) that, coupled with the
above problems, make it impossible to deal with certain categories
of error (try "hg status > /dev/full" on a Linux box).
* In Python 3, the atexit implementation is completely hidden, so
we can't hijack the platform's atexit code to run handlers at a
time of our choosing.
As a result, here's a perfectly cromulent atexit-like implementation
over which we have control. This lets us decide exactly when the
handlers run (after each request has completed), and control what
the process state is when that occurs (and afterwards).
author | Bryan O'Sullivan <bryano@fb.com> |
---|---|
date | Tue, 11 Apr 2017 14:54:12 -0700 |
parents | 7c09b071318a |
children | bf5e13e38390 |
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from __future__ import absolute_import import array import errno import fcntl import os import sys from . import ( encoding, osutil, pycompat, ) def _rcfiles(path): rcs = [os.path.join(path, 'hgrc')] rcdir = os.path.join(path, 'hgrc.d') try: rcs.extend([os.path.join(rcdir, f) for f, kind in osutil.listdir(rcdir) if f.endswith(".rc")]) except OSError: pass return rcs def systemrcpath(): path = [] if pycompat.sysplatform == 'plan9': root = 'lib/mercurial' else: root = 'etc/mercurial' # old mod_python does not set sys.argv if len(getattr(sys, 'argv', [])) > 0: p = os.path.dirname(os.path.dirname(pycompat.sysargv[0])) if p != '/': path.extend(_rcfiles(os.path.join(p, root))) path.extend(_rcfiles('/' + root)) return path def userrcpath(): if pycompat.sysplatform == 'plan9': return [encoding.environ['home'] + '/lib/hgrc'] elif pycompat.sysplatform == 'darwin': return [os.path.expanduser('~/.hgrc')] else: confighome = encoding.environ.get('XDG_CONFIG_HOME') if confighome is None or not os.path.isabs(confighome): confighome = os.path.expanduser('~/.config') return [os.path.expanduser('~/.hgrc'), os.path.join(confighome, 'hg', 'hgrc')] def termsize(ui): try: import termios TIOCGWINSZ = termios.TIOCGWINSZ # unavailable on IRIX (issue3449) except (AttributeError, ImportError): return 80, 24 for dev in (ui.ferr, ui.fout, ui.fin): try: try: fd = dev.fileno() except AttributeError: continue if not os.isatty(fd): continue arri = fcntl.ioctl(fd, TIOCGWINSZ, '\0' * 8) height, width = array.array(r'h', arri)[:2] if width > 0 and height > 0: return width, height except ValueError: pass except IOError as e: if e[0] == errno.EINVAL: pass else: raise return 80, 24