def _add_node(self, node, depth=0):
if depth > self._depth_threshold:
raise DagException("Node dependency too deep")
if node.id in self._nodes:
return self._nodes[id]
else:
self._nodes[id] = node
if self._is_node_terminal(node):
node.satisfied = True
return node
# find node ancestors and generators
for generator_class in self._generators:
required_events = generator_class.required_events(node.params)
if required_events is None:
continue
for events_join in required_events:
edge = Edge(generator_class)
for event in events_join:
parent_node = self._add_node(Node(event), depth + 1)
edge.nodes[parent_node.id] = parent_node
if edge.id in self._edges:
edge = self._edges[edge.id]
else:
self._edges[edge.id] = edge
node.edges[edge.id] = edge
return node
def add_node(self, params, demand, depth=0, session=None):
session_was_none = session is None
if session_was_none:
session = self._open_session()
node, created = Node.get_or_create(params, session)
if not created:
return node
if depth < self.depth_threshold:
self._extend_graph(node, depth, session)
if demand > 0:
node.add_demand(demand)
if session_was_none:
session.commit()
return node
def add_event(self, params):
session = self._open_session()
node, _ = Node.get_or_create(params, session)
node.satisfy(session)
session.commit()