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

[Jim Fulton]

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 ===
##############################################################################
# 
# Zope Public License (ZPL) Version 1.0
# -------------------------------------
# 
# Copyright (c) Digital Creations.  All rights reserved.
# 
# This license has been certified as Open Source(tm).
# 
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
# 
# 1. Redistributions in source code must retain the above copyright
#    notice, this list of conditions, and the following disclaimer.
# 
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions, and the following disclaimer in
#    the documentation and/or other materials provided with the
#    distribution.
# 
# 3. Digital Creations requests that attribution be given to Zope
#    in any manner possible. Zope includes a "Powered by Zope"
#    button that is installed by default. While it is not a license
#    violation to remove this button, it is requested that the
#    attribution remain. A significant investment has been put
#    into Zope, and this effort will continue if the Zope community
#    continues to grow. This is one way to assure that growth.
# 
# 4. All advertising materials and documentation mentioning
#    features derived from or use of this software must display
#    the following acknowledgement:
# 
#      "This product includes software developed by Digital Creations
#      for use in the Z Object Publishing Environment
#      (http://www.zope.org/)."
# 
#    In the event that the product being advertised includes an
#    intact Zope distribution (with copyright and license included)
#    then this clause is waived.
# 
# 5. Names associated with Zope or Digital Creations must not be used to
#    endorse or promote products derived from this software without
#    prior written permission from Digital Creations.
# 
# 6. Modified redistributions of any form whatsoever must retain
#    the following acknowledgment:
# 
#      "This product includes software developed by Digital Creations
#      for use in the Z Object Publishing Environment
#      (http://www.zope.org/)."
# 
#    Intact (re-)distributions of any official Zope release do not
#    require an external acknowledgement.
# 
# 7. Modifications are encouraged but must be packaged separately as
#    patches to official Zope releases.  Distributions that do not
#    clearly separate the patches from the original work must be clearly
#    labeled as unofficial distributions.  Modifications which do not
#    carry the name Zope may be packaged in any form, as long as they
#    conform to all of the clauses above.
# 
# 
# Disclaimer
# 
#   THIS SOFTWARE IS PROVIDED BY DIGITAL CREATIONS ``AS IS'' AND ANY
#   EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
#   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
#   PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL DIGITAL CREATIONS OR ITS
#   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
#   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
#   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
#   USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
#   ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
#   OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
#   OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
#   SUCH DAMAGE.
# 
# 
# This software consists of contributions made by Digital Creations and
# many individuals on behalf of Digital Creations.  Specific
# attributions are listed in the accompanying credits file.
# 
##############################################################################

# 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."""