Mercurial > hg
view mercurial/fancyopts.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 | 56b2bcea2529 |
children | e1f0ec0b7d2d |
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# fancyopts.py - better command line parsing # # Copyright 2005-2009 Matt Mackall <mpm@selenic.com> and others # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import getopt from .i18n import _ from . import error def gnugetopt(args, options, longoptions): """Parse options mostly like getopt.gnu_getopt. This is different from getopt.gnu_getopt in that an argument of - will become an argument of - instead of vanishing completely. """ extraargs = [] if '--' in args: stopindex = args.index('--') extraargs = args[stopindex + 1:] args = args[:stopindex] opts, parseargs = getopt.getopt(args, options, longoptions) args = [] while parseargs: arg = parseargs.pop(0) if arg and arg[0] == '-' and len(arg) > 1: parseargs.insert(0, arg) topts, newparseargs = getopt.getopt(parseargs, options, longoptions) opts = opts + topts parseargs = newparseargs else: args.append(arg) args.extend(extraargs) return opts, args def fancyopts(args, options, state, gnu=False): """ read args, parse options, and store options in state each option is a tuple of: short option or '' long option default value description option value label(optional) option types include: boolean or none - option sets variable in state to true string - parameter string is stored in state list - parameter string is added to a list integer - parameter strings is stored as int function - call function with parameter non-option args are returned """ namelist = [] shortlist = '' argmap = {} defmap = {} for option in options: if len(option) == 5: short, name, default, comment, dummy = option else: short, name, default, comment = option # convert opts to getopt format oname = name name = name.replace('-', '_') argmap['-' + short] = argmap['--' + oname] = name defmap[name] = default # copy defaults to state if isinstance(default, list): state[name] = default[:] elif callable(default): state[name] = None else: state[name] = default # does it take a parameter? if not (default is None or default is True or default is False): if short: short += ':' if oname: oname += '=' if short: shortlist += short if name: namelist.append(oname) # parse arguments if gnu: parse = gnugetopt else: parse = getopt.getopt opts, args = parse(args, shortlist, namelist) # transfer result to state for opt, val in opts: name = argmap[opt] obj = defmap[name] t = type(obj) if callable(obj): state[name] = defmap[name](val) elif t is type(1): try: state[name] = int(val) except ValueError: raise error.Abort(_('invalid value %r for option %s, ' 'expected int') % (val, opt)) elif t is type(''): state[name] = val elif t is type([]): state[name].append(val) elif t is type(None) or t is type(False): state[name] = True # return unparsed args return args