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  • Committer: Robert Collins
  • Date: 2007-07-04 08:08:13 UTC
  • mfrom: (2572 +trunk)
  • mto: This revision was merged to the branch mainline in revision 2587.
  • Revision ID: robertc@robertcollins.net-20070704080813-wzebx0r88fvwj5rq
Merge bzr.dev.

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bzrlib/lazy_import.py
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# Copyright (C) 2006 by Canonical Ltd
 
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# Copyright (C) 2006 Canonical Ltd
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#
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# This program is free software; you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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    to inherit from them).
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"""
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import re
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import sys
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from bzrlib import (
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    errors,
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    )
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class ScopeReplacer(object):
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    """A lazy object that will replace itself in the appropriate scope.
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    needed.
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    """
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    __slots__ = ('_scope', '_factory', '_name')
 
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    __slots__ = ('_scope', '_factory', '_name', '_real_obj')
 
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    # Setting this to True will allow you to do x = y, and still access members
 
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    # from both variables. This should not normally be enabled, but is useful
 
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    # when building documentation.
 
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    _should_proxy = False
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    def __init__(self, scope, factory, name):
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        """Create a temporary object in the specified scope.
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        self._scope = scope
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        self._factory = factory
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        self._name = name
 
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        self._real_obj = None
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        scope[name] = self
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    def _replace(self):
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                          " to another variable?",
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                extra=e)
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        obj = factory(self, scope, name)
 
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        if ScopeReplacer._should_proxy:
 
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            self._real_obj = obj
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        scope[name] = obj
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        return obj
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        # del self._name
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    def __getattribute__(self, attr):
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        _replace = object.__getattribute__(self, '_replace')
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        obj = _replace()
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        _cleanup = object.__getattribute__(self, '_cleanup')
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        _cleanup()
 
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        obj = object.__getattribute__(self, '_real_obj')
 
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        if obj is None:
 
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            _replace = object.__getattribute__(self, '_replace')
 
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            obj = _replace()
 
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            _cleanup = object.__getattribute__(self, '_cleanup')
 
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            _cleanup()
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        return getattr(obj, attr)
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    def __call__(self, *args, **kwargs):
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    # This is just a helper around ImportProcessor.lazy_import
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    proc = ImportProcessor(lazy_import_class=lazy_import_class)
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    return proc.lazy_import(scope, text)
 
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# The only module that this module depends on is 'bzrlib.errors'. But it
 
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# can actually be imported lazily, since we only need it if there is a
 
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# problem.
 
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lazy_import(globals(), """
 
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from bzrlib import errors
 
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""")