Package org.gcube.informationsystem.resourceregistry.persistence.orientdb.instances

Class OrphanCandidates

java.lang.Object

org.gcube.informationsystem.resourceregistry.persistence.orientdb.instances.OrphanCandidates

public class OrphanCandidates
extends Object

The targets reached by a dropped cascadeWhenOrphan relation while an instance is removed from one Context. The constraint is evaluated on the final state of the operation: the avalanche only records the targets, and removeOrphans(org.gcube.informationsystem.resourceregistry.environments.instances.InstanceEnvironment, com.orientechnologies.orient.core.db.document.ODatabaseDocument, java.util.Map<java.util.UUID, org.gcube.com.fasterxml.jackson.databind.JsonNode>) decides when it has finished, so the outcome does not depend on the order the graph is visited in.

One instance is shared by the whole avalanche of one Context, as the visited set of an addition is.

Constructor Summary

Constructors

Constructor	Description
OrphanCandidates()	Creates an empty record.

Method Summary

Modifier and Type	Method	Description
void	record(EntityManagement<?,?> target)	Records the target of a dropped cascadeWhenOrphan relation.
void	removeOrphans(InstanceEnvironment instanceEnvironment, com.orientechnologies.orient.core.db.document.ODatabaseDocument oDatabaseDocument, Map<UUID,org.gcube.com.fasterxml.jackson.databind.JsonNode> affectedInstances)	Removes from the Context every recorded target left with no incoming relation in it.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

OrphanCandidates

public OrphanCandidates()

Creates an empty record.

Method Details

record

public void record(EntityManagement<?,?> target)

Records the target of a dropped cascadeWhenOrphan relation.

Parameters:

target - the management of the target, configured as for a cascade

removeOrphans

public void removeOrphans(InstanceEnvironment instanceEnvironment,
 com.orientechnologies.orient.core.db.document.ODatabaseDocument oDatabaseDocument,
 Map<UUID,org.gcube.com.fasterxml.jackson.databind.JsonNode> affectedInstances)
                   throws org.gcube.informationsystem.resourceregistry.api.exceptions.ResourceRegistryException

Removes from the Context every recorded target left with no incoming relation in it. Every incoming relation present in the Context counts, whatever its source. Removing an orphan follows the remove constraints of its own relations, which can record new targets and leave a target evaluated before without incoming relations: the evaluation is repeated until nothing changes. The record is empty when the method returns.

Parameters:

instanceEnvironment - the Context the removal acts on

oDatabaseDocument - the session whose open transaction is evaluated

affectedInstances - the affected instances of the operation, completed with what is removed here

Throws:

org.gcube.informationsystem.resourceregistry.api.exceptions.ResourceRegistryException - if a removal fails