/*
* gets the prevailing policy in a module (e.g. a query, relation, view)
*/
private PolicyType getPrevailingPolicy(
EvolutionEvent<V> event, V nr, PolicyType previousPolicyType) {
EvolutionPolicies policies = nr.getPolicies();
// if policy for this event exist override previousPolicy coming from provider node
for (EvolutionPolicy<V> nrPolicy : policies) {
if ((nrPolicy.getSourceEvent().getEventNode().equals(event.getEventNode()))
&& (nrPolicy.getSourceEvent().getEventType() == event.getEventType())) {
return nrPolicy.getPolicyType();
}
}
// If no policy is returned check parents' policy for this event to override provider's policy
if (this.getParentNode(nr) != null) {
EvolutionEvent<V> newEvent = new EvolutionEvent<V>(/*nr,*/ event.getEventType());
return getPrevailingPolicy(newEvent, this.getParentNode(nr), previousPolicyType);
}
// if no self or parents policy exists then return provider's policy
return previousPolicyType;
}
/** makes the necessary initializations to execute propagateChanges() */
public void initializeChange(EvolutionEvent<V> event) {
for (Entry<V, Pair<Map<V, E>>> entry : this.vertices.entrySet()) { // Clear statuses of nodes.
entry.getKey().setStatus(StatusType.NO_STATUS, true);
}
for (Entry<E, Pair<V>> entry : this.edges.entrySet()) { // Clear statuses of edges.
entry.getKey().setStatus(StatusType.NO_STATUS, true);
}
V node = event.getEventNode();
V toNode = null;
V toSchema = null;
String parameter = "";
switch (node.getType()) {
case NODE_TYPE_RELATION:
case NODE_TYPE_QUERY:
case NODE_TYPE_VIEW:
toNode = node;
for (int i = 0; i < node.getOutEdges().size(); i++) {
toSchema = (V) node.getOutEdges().get(i).getToNode();
if (toSchema.getType() == NodeType.NODE_TYPE_OUTPUT) {
parameter = node.getName();
break;
}
}
break;
case NODE_TYPE_OUTPUT:
case NODE_TYPE_SEMANTICS:
toSchema = node;
for (int i = 0; i < node.getInEdges().size(); i++) {
if (node.getInEdges().get(i).getType() == EdgeType.EDGE_TYPE_OUTPUT
|| node.getInEdges().get(i).getType() == EdgeType.EDGE_TYPE_SEMANTICS) {
toNode = (V) node.getInEdges().get(i).getFromNode();
break;
}
parameter = node.getName();
if (event.getEventType() == EventType.ADD_ATTRIBUTE) {
parameter = "";
}
}
break;
default:
for (int i = 0; i < node.getInEdges().size(); i++) {
if (node.getInEdges().get(i).getFromNode().getType() == NodeType.NODE_TYPE_OUTPUT) {
toSchema = (V) node.getInEdges().get(i).getFromNode();
for (int j = 0; j < toSchema.getInEdges().size(); j++) {
if (toSchema.getInEdges().get(j).getFromNode().getType()
== NodeType.NODE_TYPE_RELATION
|| toSchema.getInEdges().get(j).getFromNode().getType()
== NodeType.NODE_TYPE_QUERY
|| toSchema.getInEdges().get(j).getFromNode().getType()
== NodeType.NODE_TYPE_VIEW) {
toNode = (V) toSchema.getInEdges().get(j).getFromNode();
}
}
parameter = node.getName();
if (event.getEventType() == EventType.DELETE_SELF) {
event.setEventType(EventType.DELETE_ATTRIBUTE);
} else if (event.getEventType() == EventType.RENAME_SELF) {
event.setEventType(EventType.RENAME_ATTRIBUTE);
}
break;
}
}
if (toSchema == null) {
while (toNode == null) {
toSchema = (V) node.getInEdges().get(0).getFromNode();
if (toSchema.getType() == NodeType.NODE_TYPE_SEMANTICS) {
event.setEventType(EventType.ALTER_SEMANTICS);
toNode = (V) toSchema.getInEdges().get(0).getFromNode();
}
}
}
break;
}
Message<V, E> firstMessage =
new Message<V, E>(toNode, toSchema, event.getEventType(), parameter);
propagateChanges(firstMessage);
}
