mercurial/fancyopts.py

largefiles: don't allow corruption to propagate after detection

basestore.get uses util.atomictempfile when checking and receiving a new
largefile ... but the close/discard logic was too clever for largefiles.
Largefiles relied on being able to discard the file and thus prevent it from
being written to the store. That was however too brittle. lfutil.copyandhash
closes the infile after writing to it ... with a 'blecch' comment. The discard
was thus a silent noop, and as a result of that corruption would be detected
... and then the corrupted files would be used anyway.

Instead we now use a tmp file and rename or unlink it after validating it.

A better solution should be implemented ... but not now.

# fancyopts.py - better command line parsing
#
#  Copyright 2005-2009 Matt Mackall <[e-mail]> 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.

import getopt, util
from i18n import _

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 getattr(default, '__call__', False):
            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]
        t = type(defmap[name])
        if t is type(fancyopts):
            state[name] = defmap[name](val)
        elif t is type(1):
            try:
                state[name] = int(val)
            except ValueError:
                raise util.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