mercurial/peer.py

encoding: add fast-path for ASCII uppercase.

This copies the performance hack from encoding.lower (c481761033bd).

The case-folding logic that kicks in on case-insensitive filesystems
hits encoding.upper hard: with a repository with 75k files, the
timings went from

  hg perfstatus
  ! wall 3.156000 comb 3.156250 user 1.625000 sys 1.531250 (best of 3)

to

  hg perfstatus
  ! wall 2.390000 comb 2.390625 user 1.078125 sys 1.312500 (best of 5)

This is a 24% decrease. For comparison, Mercurial 2.0 gives:

  hg perfstatus
  ! wall 2.172000 comb 2.171875 user 0.984375 sys 1.187500 (best of 5)

so we're only 10% slower than before we added the extra case-folding
logic.

The same decrease is seen when executing 'hg status' as normal, where
we go from:

  hg status --time
  time: real 4.322 secs (user 2.219+0.000 sys 2.094+0.000)

to

  hg status --time
  time: real 3.307 secs (user 1.750+0.000 sys 1.547+0.000)

# peer.py - repository base classes for mercurial
#
# Copyright 2005, 2006 Matt Mackall <[e-mail]>
# Copyright 2006 Vadim Gelfer <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from i18n import _
import error

class peerrepository(object):

    def capable(self, name):
        '''tell whether repo supports named capability.
        return False if not supported.
        if boolean capability, return True.
        if string capability, return string.'''
        caps = self._capabilities()
        if name in caps:
            return True
        name_eq = name + '='
        for cap in caps:
            if cap.startswith(name_eq):
                return cap[len(name_eq):]
        return False

    def requirecap(self, name, purpose):
        '''raise an exception if the given capability is not present'''
        if not self.capable(name):
            raise error.CapabilityError(
                _('cannot %s; remote repository does not '
                  'support the %r capability') % (purpose, name))

    def local(self):
        '''return peer as a localrepo, or None'''
        return None

    def peer(self):
        return self

    def peer(self):
        return self

    def canpush(self):
        return True

    def close(self):
        pass