Mercurial > hg
view hgext/pager.py @ 45095:8e04607023e5
procutil: ensure that procutil.std{out,err}.write() writes all bytes
Python 3 offers different kind of streams and it’s not guaranteed for all of
them that calling write() writes all bytes.
When Python is started in unbuffered mode, sys.std{out,err}.buffer are
instances of io.FileIO, whose write() can write less bytes for
platform-specific reasons (e.g. Linux has a 0x7ffff000 bytes maximum and could
write less if interrupted by a signal; when writing to Windows consoles, it’s
limited to 32767 bytes to avoid the "not enough space" error). This can lead to
silent loss of data, both when using sys.std{out,err}.buffer (which may in fact
not be a buffered stream) and when using the text streams sys.std{out,err}
(I’ve created a CPython bug report for that:
https://bugs.python.org/issue41221).
Python may fix the problem at some point. For now, we implement our own wrapper
for procutil.std{out,err} that calls the raw stream’s write() method until all
bytes have been written. We don’t use sys.std{out,err} for larger writes, so I
think it’s not worth the effort to patch them.
author | Manuel Jacob <me@manueljacob.de> |
---|---|
date | Fri, 10 Jul 2020 12:27:58 +0200 |
parents | 687b865b95ad |
children | 89a2afe31e82 |
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# pager.py - display output using a pager # # Copyright 2008 David Soria Parra <dsp@php.net> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. # # To load the extension, add it to your configuration file: # # [extension] # pager = # # Run 'hg help pager' to get info on configuration. '''browse command output with an external pager (DEPRECATED) Forcibly enable paging for individual commands that don't typically request pagination with the attend-<command> option. This setting takes precedence over ignore options and defaults:: [pager] attend-cat = false ''' from __future__ import absolute_import from mercurial import ( cmdutil, commands, dispatch, extensions, registrar, ) # 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' configtable = {} configitem = registrar.configitem(configtable) configitem( b'pager', b'attend', default=lambda: attended, ) def uisetup(ui): def pagecmd(orig, ui, options, cmd, cmdfunc): auto = options[b'pager'] == b'auto' if auto and not ui.pageractive: usepager = False attend = ui.configlist(b'pager', b'attend') ignore = ui.configlist(b'pager', b'ignore') cmds, _ = cmdutil.findcmd(cmd, commands.table) for cmd in cmds: var = b'attend-%s' % cmd if ui.config(b'pager', var, None): usepager = ui.configbool(b'pager', var, True) break if cmd in attend or (cmd not in ignore and not attend): usepager = True break if usepager: # Slight hack: the attend list is supposed to override # the ignore list for the pager extension, but the # core code doesn't know about attend, so we have to # lobotomize the ignore list so that the extension's # behavior is preserved. ui.setconfig(b'pager', b'ignore', b'', b'pager') ui.pager(b'extension-via-attend-' + cmd) else: ui.disablepager() return orig(ui, options, cmd, cmdfunc) extensions.wrapfunction(dispatch, b'_runcommand', pagecmd) attended = [b'annotate', b'cat', b'diff', b'export', b'glog', b'log', b'qdiff']