treemanifest: lazily load manifests
Most operations on treemanifests already visit only relevant
submanifests. Notable examples include __getitem__, __contains__,
walk/matches with matcher, diff. By making submanifests lazily loaded,
we speed up all these operations.
The lazy loading is achieved by adding a _load() method that gets
defined where we currently eagerly parse the manifest. We make sure to
call it before any access to _dirs, _files or _flags.
Some timings on the Mozilla repo (with flat manifest timings for
reference):
hg cat -r . README.txt: 1.644s -> 0.096s (0.255s)
hg diff -r .^ -r . : 1.746s -> 0.137s (0.431s)
hg files -r . python : 1.508s -> 0.146s (0.335s)
hg files -r . : 2.125s -> 2.203s (0.712s)
# peer.py - repository base classes for mercurial
#
# Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>
# Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>
#
# 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