exchange: teach pull about requested stream clones
An upcoming patch will move the invocation of stream cloning logic to
the normal pull code path (from localrepository.clone). In preparation
for this, we teach pull() and pulloperation about whether a streaming
clone is requested.
The return logic in localrepository.clone() has been reformatted
slightly because of line length issues.
# demandimport.py - global demand-loading of modules for Mercurial
#
# Copyright 2006, 2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''
demandimport - automatic demandloading of modules
To enable this module, do:
import demandimport; demandimport.enable()
Imports of the following forms will be demand-loaded:
import a, b.c
import a.b as c
from a import b,c # a will be loaded immediately
These imports will not be delayed:
from a import *
b = __import__(a)
'''
from __future__ import absolute_import
import contextlib
import os
import sys
# __builtin__ in Python 2, builtins in Python 3.
try:
import __builtin__ as builtins
except ImportError:
import builtins
contextmanager = contextlib.contextmanager
_origimport = __import__
nothing = object()
# Python 3 doesn't have relative imports nor level -1.
level = -1
if sys.version_info[0] >= 3:
level = 0
_import = _origimport
def _hgextimport(importfunc, name, globals, *args, **kwargs):
try:
return importfunc(name, globals, *args, **kwargs)
except ImportError:
if not globals:
raise
# extensions are loaded with "hgext_" prefix
hgextname = 'hgext_%s' % name
nameroot = hgextname.split('.', 1)[0]
contextroot = globals.get('__name__', '').split('.', 1)[0]
if nameroot != contextroot:
raise
# retry to import with "hgext_" prefix
return importfunc(hgextname, globals, *args, **kwargs)
class _demandmod(object):
"""module demand-loader and proxy"""
def __init__(self, name, globals, locals, level=level):
if '.' in name:
head, rest = name.split('.', 1)
after = [rest]
else:
head = name
after = []
object.__setattr__(self, "_data",
(head, globals, locals, after, level))
object.__setattr__(self, "_module", None)
def _extend(self, name):
"""add to the list of submodules to load"""
self._data[3].append(name)
def _load(self):
if not self._module:
head, globals, locals, after, level = self._data
mod = _hgextimport(_import, head, globals, locals, None, level)
# load submodules
def subload(mod, p):
h, t = p, None
if '.' in p:
h, t = p.split('.', 1)
if getattr(mod, h, nothing) is nothing:
setattr(mod, h, _demandmod(p, mod.__dict__, mod.__dict__))
elif t:
subload(getattr(mod, h), t)
for x in after:
subload(mod, x)
# are we in the locals dictionary still?
if locals and locals.get(head) == self:
locals[head] = mod
object.__setattr__(self, "_module", mod)
def __repr__(self):
if self._module:
return "<proxied module '%s'>" % self._data[0]
return "<unloaded module '%s'>" % self._data[0]
def __call__(self, *args, **kwargs):
raise TypeError("%s object is not callable" % repr(self))
def __getattribute__(self, attr):
if attr in ('_data', '_extend', '_load', '_module'):
return object.__getattribute__(self, attr)
self._load()
return getattr(self._module, attr)
def __setattr__(self, attr, val):
self._load()
setattr(self._module, attr, val)
def _demandimport(name, globals=None, locals=None, fromlist=None, level=level):
if not locals or name in ignore or fromlist == ('*',):
# these cases we can't really delay
return _hgextimport(_import, name, globals, locals, fromlist, level)
elif not fromlist:
# import a [as b]
if '.' in name: # a.b
base, rest = name.split('.', 1)
# email.__init__ loading email.mime
if globals and globals.get('__name__', None) == base:
return _import(name, globals, locals, fromlist, level)
# if a is already demand-loaded, add b to its submodule list
if base in locals:
if isinstance(locals[base], _demandmod):
locals[base]._extend(rest)
return locals[base]
return _demandmod(name, globals, locals, level)
else:
# There is a fromlist.
# from a import b,c,d
# from . import b,c,d
# from .a import b,c,d
# level == -1: relative and absolute attempted (Python 2 only).
# level >= 0: absolute only (Python 2 w/ absolute_import and Python 3).
# The modern Mercurial convention is to use absolute_import everywhere,
# so modern Mercurial code will have level >= 0.
if level >= 0:
# Mercurial's enforced import style does not use
# "from a import b,c,d" or "from .a import b,c,d" syntax. In
# addition, this appears to be giving errors with some modules
# for unknown reasons. Since we shouldn't be using this syntax
# much, work around the problems.
if name:
return _hgextimport(_origimport, name, globals, locals,
fromlist, level)
mod = _hgextimport(_origimport, name, globals, locals, level=level)
for x in fromlist:
# Missing symbols mean they weren't defined in the module
# itself which means they are sub-modules.
if getattr(mod, x, nothing) is nothing:
setattr(mod, x,
_demandmod(x, mod.__dict__, locals, level=level))
return mod
# But, we still need to support lazy loading of standard library and 3rd
# party modules. So handle level == -1.
mod = _hgextimport(_origimport, name, globals, locals)
# recurse down the module chain
for comp in name.split('.')[1:]:
if getattr(mod, comp, nothing) is nothing:
setattr(mod, comp,
_demandmod(comp, mod.__dict__, mod.__dict__))
mod = getattr(mod, comp)
for x in fromlist:
# set requested submodules for demand load
if getattr(mod, x, nothing) is nothing:
setattr(mod, x, _demandmod(x, mod.__dict__, locals))
return mod
ignore = [
'__future__',
'_hashlib',
'_xmlplus',
'fcntl',
'win32com.gen_py',
'_winreg', # 2.7 mimetypes needs immediate ImportError
'pythoncom',
# imported by tarfile, not available under Windows
'pwd',
'grp',
# imported by profile, itself imported by hotshot.stats,
# not available under Windows
'resource',
# this trips up many extension authors
'gtk',
# setuptools' pkg_resources.py expects "from __main__ import x" to
# raise ImportError if x not defined
'__main__',
'_ssl', # conditional imports in the stdlib, issue1964
'rfc822',
'mimetools',
# setuptools 8 expects this module to explode early when not on windows
'distutils.msvc9compiler'
]
def isenabled():
return builtins.__import__ == _demandimport
def enable():
"enable global demand-loading of modules"
if os.environ.get('HGDEMANDIMPORT') != 'disable':
builtins.__import__ = _demandimport
def disable():
"disable global demand-loading of modules"
builtins.__import__ = _origimport
@contextmanager
def deactivated():
"context manager for disabling demandimport in 'with' blocks"
demandenabled = isenabled()
if demandenabled:
disable()
try:
yield
finally:
if demandenabled:
enable()