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Viewing changes to lib/lp/services/longpoll/adapters/storm.py

  • Committer: Stuart Bishop
  • Date: 2011-09-28 12:49:24 UTC
  • mfrom: (9893.10.1 trivial)
  • mto: This revision was merged to the branch mainline in revision 14178.
  • Revision ID: stuart.bishop@canonical.com-20110928124924-m5a22fymqghw6c5i
Merged trivial into distinct-db-users.

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lib/lp/services/longpoll/adapters/storm.py
 
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# Copyright 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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"""Long-poll life-cycle adapters."""
 
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from __future__ import absolute_import
 
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__metaclass__ = type
 
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__all__ = []
 
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from lazr.lifecycle.interfaces import (
 
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    IObjectCreatedEvent,
 
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    IObjectDeletedEvent,
 
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    IObjectModifiedEvent,
 
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    )
 
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from storm.base import Storm
 
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from storm.info import get_obj_info
 
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from zope.component import adapter
 
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from zope.interface.interfaces import IAttribute
 
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from lp.services.longpoll.adapters.event import (
 
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    generate_event_key,
 
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    LongPollEvent,
 
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    )
 
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from lp.services.longpoll.interfaces import (
 
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    ILongPollEvent,
 
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    long_poll_event,
 
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    )
 
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@long_poll_event(Storm)
 
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class LongPollStormEvent(LongPollEvent):
 
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    """A `ILongPollEvent` for events of `Storm` objects.
 
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    This class knows how to construct a stable event key given a Storm object.
 
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    """
 
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    @property
 
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    def event_key(self):
 
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        """See `ILongPollEvent`.
 
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        Constructs the key from the table name and primary key values of the
 
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        Storm model object.
 
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        """
 
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        cls_info = get_obj_info(self.source).cls_info
 
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        return generate_event_key(
 
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            cls_info.table.name.lower(), *(
 
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                primary_key_column.__get__(self.source)
 
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                for primary_key_column in cls_info.primary_key))
 
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@adapter(Storm, IObjectCreatedEvent)
 
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def object_created(model_instance, object_event):
 
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    """Subscription handler for `Storm` creation events."""
 
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    event = ILongPollEvent(model_instance)
 
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    event.emit(what="created")
 
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@adapter(Storm, IObjectDeletedEvent)
 
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def object_deleted(model_instance, object_event):
 
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    """Subscription handler for `Storm` deletion events."""
 
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    event = ILongPollEvent(model_instance)
 
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    event.emit(what="deleted")
 
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@adapter(Storm, IObjectModifiedEvent)
 
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def object_modified(model_instance, object_event):
 
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    """Subscription handler for `Storm` modification events."""
 
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    edited_fields = object_event.edited_fields
 
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    if edited_fields is not None and len(edited_fields) != 0:
 
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        edited_field_names = sorted(
 
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            (field.__name__ if IAttribute.providedBy(field) else field)
 
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            for field in edited_fields)
 
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        event = ILongPollEvent(model_instance)
 
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        event.emit(what="modified", edited_fields=edited_field_names)