Mercurial > hg
view hgext/pager.py @ 27430:e240e914d226 stable
revlog: seek to end of file before writing (issue4943)
Revlogs were recently refactored to open file handles in "a+" and use a
persistent file handle for reading and writing. This drastically
reduced the number of file handles being opened.
Unfortunately, it appears that some versions of Solaris lose the file
offset when performing a write after the handle has been seeked.
The simplest workaround is to seek to EOF on files opened in a+ mode
before writing to them, which is what this patch does.
Ideally, this code would exist in the vfs layer. However, this would
require creating a proxy class for file objects in order to provide a
custom implementation of write(). This would add overhead. Since
revlogs are the only files we open in a+ mode, the one-off workaround
in revlog.py should be sufficient.
This patch appears to have little to no impact on performance on my
Linux machine.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Thu, 17 Dec 2015 17:16:02 -0800 |
parents | 62c5e937f477 |
children | efceacd6a0c6 |
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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 To set the pager that should be used, set the application variable:: [pager] pager = less -FRX If no pager is set, the pager extensions uses the environment variable $PAGER. If neither pager.pager, nor $PAGER is set, no pager is used. You can disable the pager for certain commands by adding them to the pager.ignore list:: [pager] ignore = version, help, update You can also enable the pager only for certain commands using pager.attend. Below is the default list of commands to be paged:: [pager] attend = annotate, cat, diff, export, glog, log, qdiff Setting pager.attend to an empty value will cause all commands to be paged. If pager.attend is present, pager.ignore will be ignored. Lastly, you can enable and disable paging for individual commands with the attend-<command> option. This setting takes precedence over existing attend and ignore options and defaults:: [pager] attend-cat = false To ignore global commands like :hg:`version` or :hg:`help`, you have to specify them in your user configuration file. The --pager=... option can also be used to control when the pager is used. Use a boolean value like yes, no, on, off, or use auto for normal behavior. ''' import atexit, sys, os, signal, subprocess from mercurial import commands, dispatch, util, extensions, cmdutil from mercurial.i18n import _ # Note for extension authors: ONLY specify testedwith = 'internal' 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 = 'internal' def _runpager(ui, p): pager = subprocess.Popen(p, shell=True, bufsize=-1, close_fds=util.closefds, stdin=subprocess.PIPE, stdout=sys.stdout, stderr=sys.stderr) # back up original file objects and descriptors olduifout = ui.fout oldstdout = sys.stdout stdoutfd = os.dup(sys.stdout.fileno()) stderrfd = os.dup(sys.stderr.fileno()) # create new line-buffered stdout so that output can show up immediately ui.fout = sys.stdout = newstdout = os.fdopen(sys.stdout.fileno(), 'wb', 1) os.dup2(pager.stdin.fileno(), sys.stdout.fileno()) if ui._isatty(sys.stderr): os.dup2(pager.stdin.fileno(), sys.stderr.fileno()) @atexit.register def killpager(): if util.safehasattr(signal, "SIGINT"): signal.signal(signal.SIGINT, signal.SIG_IGN) pager.stdin.close() ui.fout = olduifout sys.stdout = oldstdout # close new stdout while it's associated with pager; otherwise stdout # fd would be closed when newstdout is deleted newstdout.close() # restore original fds: stdout is open again os.dup2(stdoutfd, sys.stdout.fileno()) os.dup2(stderrfd, sys.stderr.fileno()) pager.wait() def uisetup(ui): if '--debugger' in sys.argv or not ui.formatted(): return def pagecmd(orig, ui, options, cmd, cmdfunc): p = ui.config("pager", "pager", os.environ.get("PAGER")) usepager = False always = util.parsebool(options['pager']) auto = options['pager'] == 'auto' if not p: pass elif always: usepager = True elif not auto: usepager = False else: attend = ui.configlist('pager', 'attend', attended) ignore = ui.configlist('pager', 'ignore') cmds, _ = cmdutil.findcmd(cmd, commands.table) for cmd in cmds: var = 'attend-%s' % cmd if ui.config('pager', var): usepager = ui.configbool('pager', var) break if (cmd in attend or (cmd not in ignore and not attend)): usepager = True break setattr(ui, 'pageractive', usepager) if usepager: ui.setconfig('ui', 'formatted', ui.formatted(), 'pager') ui.setconfig('ui', 'interactive', False, 'pager') if util.safehasattr(signal, "SIGPIPE"): signal.signal(signal.SIGPIPE, signal.SIG_DFL) _runpager(ui, p) return orig(ui, options, cmd, cmdfunc) # Wrap dispatch._runcommand after color is loaded so color can see # ui.pageractive. Otherwise, if we loaded first, color's wrapped # dispatch._runcommand would run without having access to ui.pageractive. def afterloaded(loaded): extensions.wrapfunction(dispatch, '_runcommand', pagecmd) extensions.afterloaded('color', afterloaded) def extsetup(ui): commands.globalopts.append( ('', 'pager', 'auto', _("when to paginate (boolean, always, auto, or never)"), _('TYPE'))) attended = ['annotate', 'cat', 'diff', 'export', 'glog', 'log', 'qdiff']