[Zope-Checkins] CVS: Zope/lib/python/Persistence - IPersistent.py:1.1.2.1

Jim Fulton jim@zope.com
Thu, 8 Nov 2001 15:51:22 -0500


Update of /cvs-repository/Zope/lib/python/Persistence
In directory cvs.zope.org:/tmp/cvs-serv18003

Added Files:
      Tag: ComponentArchitecture-branch
	IPersistent.py 
Log Message:
Added to support initial work toward ExtensionClass-less
implementation for Python 2.2.


=== Added File Zope/lib/python/Persistence/IPersistent.py ===
##############################################################################
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# Hack to overcome absense of Interface package
try:
    from Interface import Interface, Attribute
except ImportError:
    class Interface: pass
    def Attribute(*args): return args

class IPersistent(Interface):
    """Python persistence interface

    Note that there is a separate C API that is n ot included here.
    The C API requires a specific data layouit and defines an
    additional state, 'sticky' that is used to pevent object
    deactivation while in C routines.
    """

    _p_jar=Attribute(
        """The data manager for the object

        If there is no data manager, then this is None.
        """)

    _p_oid=Attribute(
        """The object id

        It is up to the data manager to assign this.
        The special value None is resrved to indicate that an object
        id has not been assigned.
        """)

    _p_changed=Attribute(
        """The persistence state of the object

        This is one of:

        None -- The object is a ghost. It is not active.

        false -- The object is up to date (or has never been saved.

        true -- The object has been modified.

        The object state may be changed by assigning this attribute,
        however, assigning None is ignored if the object is not in the
        up-to-date state.

        Deleting this attribute forces deactivation independent of
        existing state.

        Note that an attribute is used for this to allow optimized
        cache implementations.
        """)

    _p_serial=Attribute(
        """The object serial number

        This is an arbitrary object.

        Note: The current implementation requires this to be an
              8-charactr string. This is a bug.
        """)

    def __getstate__():
        """Get the object state data.

        The state should not include peristent attributes ("_p_name")
        """

    def __setstate__(state):
        """Set the object state data

        Note that this does not affect the object's persistence state.
        """
    
    def _p_deactivate():
        """Deactivate the object

        Change the object to the ghost state is it is in the
        up-to-date state."""