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Viewing changes to lib/lpresults/repository/state.py

  • Committer: Marc Tardif
  • Date: 2011-08-09 15:46:45 UTC
  • Revision ID: marc.tardif@canonical.com-20110809154645-i151emhk6onjggx5
Added hardware for systems and system units.

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lib/lpresults/repository/state.py
 
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# Copyright 2010-2011 Canonical Ltd.  This software is licensed under the
 
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# GNU Affero General Public License version 3 (see the file LICENSE).
 
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__metaclass__ = type
 
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__all__ = [
 
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    "State",
 
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    ]
 
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_state_types = {}
 
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def register_state(state):
 
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    """Register a class to be an implementation for L{State}s.
 
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    The class's C{__state_name__} must be defined as a string and
 
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    C{__state_parent__} as a class.
 
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    """
 
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    if "__state_name__" not in state.__dict__:
 
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        state.__state_name__ = ""
 
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    if "__state_parent__" not in state.__dict__:
 
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        state.__state_parent__ = None
 
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    _state_types[state] = {}
 
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    if state.__state_parent__ is not None:
 
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        if state.__state_parent__ not in _state_types:
 
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            raise RuntimeError("%r state ancestor does not exist already"
 
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                % state.__state_parent__)
 
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        if state.__state_name__ in _state_types[state.__state_parent__]:
 
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            raise RuntimeError("%s state name already in ancestor %r"
 
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                % (state.__state_name__, state.__state_parent__))
 
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        _state_types[state.__state_parent__][state.__state_name__] = state
 
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class StateMeta(type):
 
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    def __init__(cls, name, bases, dict):
 
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        super(StateMeta, cls).__init__(name, bases, dict)
 
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        register_state(cls)
 
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class State:
 
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    __metaclass__ = StateMeta
 
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    __slots__ = ("parent",)
 
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    def __init__(self, parent=None):
 
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        self.parent = parent
 
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    @property
 
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    def depth(self):
 
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        depth = 0
 
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        state = self.parent
 
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        while state is not None:
 
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            depth += 1
 
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            state = state.parent
 
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        return depth
 
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    def getSibling(self):
 
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        cls = self.__class__
 
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        return cls(self.parent)
 
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    def getChild(self, name=""):
 
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        cls = self.__class__
 
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        children = _state_types[cls]
 
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        if not children:
 
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            raise Exception("State has no children: %s" % cls)
 
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        if name not in children:
 
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            raise Exception("State does not have child: %s" % name)
 
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        return children[name](self)
 
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    def handleEntry(self, result, *args):
 
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        pass