mercurial/peer.py

revset: add fast path for _list() of integer revisions

This can greatly speed up chained 'or' of integer revisions.

1) reduce nesting of chained 'or' operations
2) optimize to a list
3) fast path for integer revisions (this patch)

revset #0: 0 + 1 + 2 + ... + 1000
1) wall 0.483341 comb 0.480000 user 0.480000 sys 0.000000 (best of 20)
2) wall 0.025393 comb 0.020000 user 0.020000 sys 0.000000 (best of 107)
3) wall 0.008371 comb 0.000000 user 0.000000 sys 0.000000 (best of 317)

revset #1: sort(0 + 1 + 2 + ... + 1000)
1) wall 0.035240 comb 0.040000 user 0.040000 sys 0.000000 (best of 100)
2) wall 0.026432 comb 0.030000 user 0.030000 sys 0.000000 (best of 102)
3) wall 0.008418 comb 0.000000 user 0.000000 sys 0.000000 (best of 322)

revset #2: first(0 + 1 + 2 + ... + 1000)
1) wall 0.028949 comb 0.030000 user 0.030000 sys 0.000000 (best of 100)
2) wall 0.025503 comb 0.030000 user 0.030000 sys 0.000000 (best of 106)
3) wall 0.008423 comb 0.010000 user 0.010000 sys 0.000000 (best of 319)

But I admit that it is still slower than the spanset.

revset #3: 0:1000
3) wall 0.000132 comb 0.000000 user 0.000000 sys 0.000000 (best of 19010)

# 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 canpush(self):
        return True

    def close(self):
        pass