Mercurial > hg
view hgdemandimport/demandimportpy2.py @ 45412:aaeccdb6e654 stable
repoview: pin revisions for `local` and `other` when a merge is active
I've hit this a couple of times, where pulling with a dirty `wdir` obsoletes
`p1` and updating to the successor results in merge conflicts. The problem was
resolving them failed immediately, complaining that the old checkout was
filtered.
The change in `test-rebase-obsolete.t` is because there's an outstanding merge
conflict in a rebase operation. The summary prompt to merge seems incorrect for
this scenario, but that's an existing issue.
Differential Revision: https://phab.mercurial-scm.org/D8980
author | Matt Harbison <matt_harbison@yahoo.com> |
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date | Fri, 04 Sep 2020 15:21:02 -0400 |
parents | be8552f25cab |
children | d4ba4d51f85f |
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# 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 __builtin__ as builtins import contextlib import sys from . import tracing contextmanager = contextlib.contextmanager _origimport = __import__ nothing = object() 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 Specify 1 as 'level' argument at construction, to import module relatively. """ def __init__(self, name, globals, locals, level): if '.' in name: head, rest = name.split('.', 1) after = [rest] else: head = name after = [] object.__setattr__( self, "_data", (head, globals, locals, after, level, set()) ) object.__setattr__(self, "_module", None) def _extend(self, name): """add to the list of submodules to load""" self._data[3].append(name) def _addref(self, name): """Record that the named module ``name`` imports this module. References to this proxy class having the name of this module will be replaced at module load time. We assume the symbol inside the importing module is identical to the "head" name of this module. We don't actually know if "as X" syntax is being used to change the symbol name because this information isn't exposed to __import__. """ self._data[5].add(name) def _load(self): if not self._module: with tracing.log('demandimport %s', self._data[0]): head, globals, locals, after, level, modrefs = self._data mod = _hgextimport( _origimport, head, globals, locals, None, level ) if mod is self: # In this case, _hgextimport() above should imply # _demandimport(). Otherwise, _hgextimport() never # returns _demandmod. This isn't intentional behavior, # in fact. (see also issue5304 for detail) # # If self._module is already bound at this point, self # should be already _load()-ed while _hgextimport(). # Otherwise, there is no way to import actual module # as expected, because (re-)invoking _hgextimport() # should cause same result. # This is reason why _load() returns without any more # setup but assumes self to be already bound. mod = self._module assert mod and mod is not self, "%s, %s" % (self, mod) return # 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__, level=1), ) elif t: subload(getattr(mod, h), t) for x in after: subload(mod, x) # Replace references to this proxy instance with the # actual module. if locals: if locals.get(head) is self: locals[head] = mod elif locals.get(head + 'mod') is self: locals[head + 'mod'] = mod for modname in modrefs: modref = sys.modules.get(modname, None) if modref and getattr(modref, head, None) is self: setattr(modref, 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 __getattr__(self, attr): self._load() return getattr(self._module, attr) def __setattr__(self, attr, val): self._load() setattr(self._module, attr, val) @property def __dict__(self): self._load() return self._module.__dict__ @property def __doc__(self): self._load() return self._module.__doc__ _pypy = '__pypy__' in sys.builtin_module_names def _demandimport(name, globals=None, locals=None, fromlist=None, level=-1): if locals is None or name in ignores or fromlist == ('*',): # these cases we can't really delay return _hgextimport(_origimport, 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 _origimport(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. # The name of the module the import statement is located in. globalname = globals.get('__name__') def processfromitem(mod, attr): """Process an imported symbol in the import statement. If the symbol doesn't exist in the parent module, and if the parent module is a package, it must be a module. We set missing modules up as _demandmod instances. """ symbol = getattr(mod, attr, nothing) nonpkg = getattr(mod, '__path__', nothing) is nothing if symbol is nothing: if nonpkg: # do not try relative import, which would raise ValueError, # and leave unknown attribute as the default __import__() # would do. the missing attribute will be detected later # while processing the import statement. return mn = '%s.%s' % (mod.__name__, attr) if mn in ignores: importfunc = _origimport else: importfunc = _demandmod symbol = importfunc(attr, mod.__dict__, locals, level=1) setattr(mod, attr, symbol) # Record the importing module references this symbol so we can # replace the symbol with the actual module instance at load # time. if globalname and isinstance(symbol, _demandmod): symbol._addref(globalname) def chainmodules(rootmod, modname): # recurse down the module chain, and return the leaf module mod = rootmod for comp in modname.split('.')[1:]: obj = getattr(mod, comp, nothing) if obj is nothing: obj = _demandmod(comp, mod.__dict__, mod.__dict__, level=1) setattr(mod, comp, obj) elif mod.__name__ + '.' + comp in sys.modules: # prefer loaded module over attribute (issue5617) obj = sys.modules[mod.__name__ + '.' + comp] mod = obj return mod if level >= 0: if name: # "from a import b" or "from .a import b" style rootmod = _hgextimport( _origimport, name, globals, locals, level=level ) mod = chainmodules(rootmod, name) elif _pypy: # PyPy's __import__ throws an exception if invoked # with an empty name and no fromlist. Recreate the # desired behaviour by hand. mn = globalname mod = sys.modules[mn] if getattr(mod, '__path__', nothing) is nothing: mn = mn.rsplit('.', 1)[0] mod = sys.modules[mn] if level > 1: mn = mn.rsplit('.', level - 1)[0] mod = sys.modules[mn] else: mod = _hgextimport( _origimport, name, globals, locals, level=level ) for x in fromlist: processfromitem(mod, x) 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) mod = chainmodules(mod, name) for x in fromlist: processfromitem(mod, x) return mod ignores = set() def init(ignoreset): global ignores ignores = ignoreset def isenabled(): return builtins.__import__ == _demandimport def enable(): """enable global demand-loading of modules""" 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()