def __init__(self, cache=None):
# {(InstanceInfo(instance).model_info.model, instance.pk): InstanceInfo, ...}}
self._alive = WeakValueDictionary()
# {InstanceInfo(instance): instance, ...}}
self._dirty = {}
if cache is not None:
self._cache = cache
else:
self._cache = MRUCache(settings.MAX_CACHE)
signals.register(
(
"instance-deleted",
"start-tracking-changes",
"stop-tracking-changes",
"model-pre-init",
"model-post-init",
"model-pre-save",
"model-post-save",
"model-pre-delete",
"model-post-delete",
"model-pre-update",
"model-post-update",
# "model-history-reset",
# "model-history-redo",
# "model-history-undo",
"relation-pre-get",
"relation-post-get",
"relation-pre-set",
"relation-post-set",
"relation-pre-delete",
"relation-post-delete",
"relation-pre-add",
"relation-post-add",
"relation-pre-remove",
"relation-post-remove",
"model-do-cache",
"model-do-not-cache",
),
self
)
signals.register_with_callback("cache-rollback", self, "rollback")
class Storage(object):
def __init__(self, cache=None):
# {(InstanceInfo(instance).model_info.model, instance.pk): InstanceInfo, ...}}
self._alive = WeakValueDictionary()
# {InstanceInfo(instance): instance, ...}}
self._dirty = {}
if cache is not None:
self._cache = cache
else:
self._cache = MRUCache(settings.MAX_CACHE)
signals.register(
(
"instance-deleted",
"start-tracking-changes",
"stop-tracking-changes",
"model-pre-init",
"model-post-init",
"model-pre-save",
"model-post-save",
"model-pre-delete",
"model-post-delete",
"model-pre-update",
"model-post-update",
# "model-history-reset",
# "model-history-redo",
# "model-history-undo",
"relation-pre-get",
"relation-post-get",
"relation-pre-set",
"relation-post-set",
"relation-pre-delete",
"relation-post-delete",
"relation-pre-add",
"relation-post-add",
"relation-pre-remove",
"relation-post-remove",
"model-do-cache",
"model-do-not-cache",
),
self
)
signals.register_with_callback("cache-rollback", self, "rollback")
def get(self, query):
return QuerySetIterator(query, self)
def clear(self):
self._dirty.clear()
self._alive.clear()
self._cache.clear()
def set_dirty(self, inst_info):
self._dirty[inst_info] = inst_info.get_inst()
def cache(self, inf):
self._alive.pop((inf.model_info.model, inf._lazypkval), None)
self._alive[(inf.model_info.model, inf.get_pk_as_key())] = inf
self._cache.add(inf)
def uncache(self, inf):
if inf in self._cache:
self._cache.remove(inf)
self._dirty.pop(inf, None)
self._alive.pop((inf.model_info.model, inf.get_pk_as_key()), None)
self._alive.pop((inf.model_info.model, inf._lazypkval), None)
### signals ###
#??? what is this used for?
def instance_deleted(self, inst_info):
print "instance_deleted", inst_info
def model_pre_init(self, instance, **kwargs):
signals.fire("stop-tracking-changes", instance=instance)
def model_post_init(self, instance, **kwargs):
inf = get_inst_info(instance)
signals.fire("start-tracking-changes", instance=instance)
self._alive[(inf.model_info.model, inf.get_pk_as_key())] = inf
# If instance was not initialized with a value for primary key,
# then it has not been saved yet and goes into self._dirty.
if instance.pk is None:
self.set_dirty(inf)
def start_tracking_changes(self, instance):
get_inst_info(instance)._meta["track-changes"] = True
def stop_tracking_changes(self, instance):
get_inst_info(instance)._meta["track-changes"] = False
def model_pre_save(self, instance):
pass
def model_post_save(self, instance, created):
inf = get_inst_info(instance)
if not inf._meta["do-cache"]:
return
self.cache(inf)
self._dirty.pop(inf, None)
# On calling Model.delete, tracking of changes is stopped, so start
# tracking now.
signals.fire("start-tracking-changes", instance=instance)
def model_pre_update(self, instance, value, fieldname):
# instance._inst_info.record_change(fieldname, value)
pass
def model_post_update(self, instance, value, fieldname):
inf = get_inst_info(instance)
if not inf in self._dirty:
self.set_dirty(inf)
def model_pre_delete(self, instance):
signals.fire("stop-tracking-changes", instance=instance)
def model_post_delete(self, instance, deleted):
if not deleted:
return
inf = get_inst_info(instance)
self.uncache(inf)
instance.id = None
def model_do_cache(self, instance):
inf = get_inst_info(instance)
self.cache(inf)
self.set_dirty(inf)
inf._meta["do-cache"] = True
signals.fire("start-tracking-changes", instance=instance)
def model_do_not_cache(self, instance):
inf = get_inst_info(instance)
self.uncache(inf)
inf._meta["do-cache"] = False
signals.fire("stop-tracking-changes", instance=instance)
def model_history_reset(self, instance, **kwargs):
raise NotImplementedError
def model_history_undo(self, instance, fieldname, **kwargs):
raise NotImplementedError
def model_history_redo(self, instance, fieldname, **kwargs):
raise NotImplementedError
def relation_pre_get(self, manager, **kwargs):
pass
def relation_post_get(self, manager, **kwargs):
pass
def relation_pre_set(self, manager, values, **kwargs):
pass
def relation_post_set(self, manager, values, **kwargs):
pass
def relation_pre_delete(self, manager, **kwargs):
pass
def relation_post_delete(self, manager, **kwargs):
pass
def relation_pre_add(self, manager, values, **kwargs):
pass
def relation_post_add(self, manager, values, **kwargs):
pass
def relation_pre_remove(self, manager, values, **kwargs):
pass
def relation_post_remove(self, manager, values, **kwargs):
pass
