Class References as part of the Object graph

[tschuehly]

We are building an application where the Idea is that it is extensible by allowing to create new DataItems.

A new module could for example create "Person.java" class that extends the abstract class "DataItem.java".

We are using EclipseStore for persistence and have root object:

public class DataItemRoot {
    final Map<Class<? extends DataItem>, Map<UUID,Lazy<DataItem>>> dataItemDefinitionsByType = new ConcurrentHashMap<>();
}

The idea is that you can create a generic DataItemRepository and pass in the class of DataItem you want to work with.

This way we can create a basic CrudRepository really fast:

  @Override
  @Read
  public <T extends DataItem> List<T> getAll(Class<T> clazz) {
    return getUuidMapByClass(clazz).values()
        .stream()
        .map(Referencing::get)
        .map(it -> (T) it)
        .toList();
  }

Is this a valid way of working with EclipseStore?
I sometimes run into Exceptions that the ooid does not match with the loaded from the storage.

org.eclipse.serializer.persistence.exceptions.PersistenceExceptionConsistencyObjectId: Inconsistent Object id. Registered: 1000000000000000650, passed: 1000000000000000069
	at org.eclipse.serializer.persistence.types.DefaultObjectRegistry.synchValidateObjectNotYetRegistered(DefaultObjectRegistry.java:757) ~[persistence-1.3.1.jar:na]
	at org.eclipse.serializer.persistence.types.DefaultObjectRegistry.synchAddGetCheck(DefaultObjectRegistry.java:675) ~[persistence-1.3.1.jar:na]
	at org.eclipse.serializer.persistence.types.DefaultObjectRegistry.synchAddGet(DefaultObjectRegistry.java:765) ~[persistence-1.3.1.jar:na]
	at org.eclipse.serializer.persistence.types.DefaultObjectRegistry.optionalRegisterObject(DefaultObjectRegistry.java:583) ~[persistence-1.3.1.jar:na]
	at org.eclipse.serializer.persistence.binary.types.BinaryLoader$Default.getEffectiveInstance(BinaryLoader.java:316) ~[persistence-binary-1.3.1.jar:na]
	at org.eclipse.serializer.persistence.binary.types.BinaryLoader$Default.getBuildInstance(BinaryLoader.java:646) ~[persistence-binary-1.3.1.jar:na]
	at org.eclipse.serializer.persistence.binary.types.BinaryLoader$Default.lookupObject(BinaryLoader.java:335) ~[persistence-binary-1.3.1.jar:na]
	at org.eclipse.serializer.persistence.binary.types.BinaryValueFunctions$27.setValueToMemory(BinaryValueFunctions.java:468) ~[persistence-binary-1.3.1.jar:na]
	at org.eclipse.serializer.persistence.binary.types.Binary.updateFixedSize(Binary.java:2045) ~[persistence-binary-1.3.1.jar:na]
	at org.eclipse.serializer.persistence.binary.types.AbstractBinaryHandlerReflective.updateState(AbstractBinaryHandlerReflective.java:542) ~[persistence-binary-1.3.1.jar:na]
	at org.eclipse.serializer.persistence.binary.types.AbstractBinaryHandlerReflective.updateState(AbstractBinaryHandlerReflective.java:44) ~[persistence-binary-1.3.1.jar:na]
	at org.eclipse.serializer.persistence.types.PersistenceTypeHandler.initializeState(PersistenceTypeHandler.java:84) ~[persistence-1.3.1.jar:na]
	at org.eclipse.serializer.persistence.binary.types.BinaryLoader$Default.buildInstances(BinaryLoader.java:458) ~[persistence-binary-1.3.1.jar:na]
	at org.eclipse.serializer.persistence.binary.types.BinaryLoader$Default.build(BinaryLoader.java:396) ~[persistence-binary-1.3.1.jar:na]
	at org.eclipse.serializer.persistence.binary.types.BinaryLoader$Default.getObject(BinaryLoader.java:843) ~[persistence-binary-1.3.1.jar:na]
	at org.eclipse.serializer.persistence.types.PersistenceManager$Default.getObject(PersistenceManager.java:411) ~[persistence-1.3.1.jar:na]
	at org.eclipse.store.storage.types.StorageConnection.getObject(StorageConnection.java:455) ~[storage-1.3.1.jar:na]
	at org.eclipse.store.storage.types.Database$Default.getObject(Database.java:159) ~[storage-1.3.1.jar:na]
	at org.eclipse.serializer.reference.Lazy$Default.load(Lazy.java:435) ~[base-1.3.1.jar:na]
	at org.eclipse.serializer.reference.Lazy$Default.get(Lazy.java:416) ~[base-1.3.1.jar:na]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
	at java.base/java.util.HashMap$ValueSpliterator.forEachRemaining(HashMap.java:1787) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:575) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.evaluateToArrayNode(AbstractPipeline.java:260) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline.toArray(ReferencePipeline.java:616) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline.toArray(ReferencePipeline.java:622) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline.toList(ReferencePipeline.java:627) ~[na:na]
	at io.alanda.davinci.dataitem.store.EclipseStoreDataItemRepository.getAll(EclipseStoreDataItemRepository.java:62) ~[classes/:na]
	at io.alanda.davinci.dataitem.GenericDataItemRepository.getAll(GenericDataItemRepository.java:16) ~[classes/:na]

[hg-ms]

Hi,
Your code snippets are OK, the exception must have another reason.
I’m not able to reproduce the PersistenceExceptionConsistencyObjectId exception.
Can you provide a build-able reproduction example?
The exception indicates that an object, that gets lazy loaded, is already registered to the storage.

You also may check if your code ensures that there are no modifications done to object graph when a store operation is in progress.

[tschuehly]

We switched to non lazy lists for now, will create an example if it happens again