Package one.microstream.persistence.types

Interface Persister

All Superinterfaces:
ObjectSwizzling, PersistenceStoring
All Known Subinterfaces:
Database, EmbeddedStorageManager, PersistenceManager<D>, StorageConnection, StorageManager, ViewerBinaryPersistenceManager
All Known Implementing Classes:
Database.Default, EmbeddedStorageManager.Default, PersistenceManager.Default, StorageConnection.Default, ViewerBinaryPersistenceManager.Default
public interface Persister
extends ObjectSwizzling, PersistenceStoring

  • Method Summary

    Modifier and Type Method Description
    Storer createEagerStorer()
    Creates a new Storer instance with eager storing behavior.
    Storer createLazyStorer()
    Creates a new Storer instance with lazy storing behavior.
    Storer createStorer()
    Creates a new Storer instance with default storing behavior.
    Object getObject​(long objectId)
    Retrieves the instance associated with the passed objectId.
    long store​(Object instance)
    Stores the passed instance in any case and all referenced instances of persistable references recursively, but stores referenced instances only if they are newly encountered (e.g.
    void storeAll​(Iterable<?> instances)
    Convenience method to PersistenceStoring.store(Object) all instances of an Iterable type, usually a collection.
    The passed instance itself is NOT stored.
    Note that this method does not return an array of objectIds, since the amount of instances supplied by the passed Iterable cannot be known until after all instances have been stored and the memory and performance overhead to collect them dynamically would not be worth it in most cases since the returned array is hardly ever needed.
    long[] storeAll​(Object... instances)
    Convenience method to PersistenceStoring.store(Object) multiple instances.

  • Method Details

    • getObject

      Object getObject​(long objectId)
      Retrieves the instance associated with the passed objectId. Retrieving means guaranteeing that the associated instance is returned. If it does not yet exist, it will be created from persisted data, including all non-lazily referenced objects it is connected to.
      Specified by:
      getObject in interface ObjectSwizzling
      Parameters:
      objectId - the objectId defining which instance to return.
      Returns:
      the instance associated with the passed objectId.

    • store

      long store​(Object instance)
      Stores the passed instance in any case and all referenced instances of persistable references recursively, but stores referenced instances only if they are newly encountered (e.g. don't have an id associated with them in the object registry, yet and are therefore required to be handled). This is useful for the common case of just storing an updated instance and potentially newly created instances along with it while skipping all existing (and normally unchanged) referenced instances.

      Specified by:
      store in interface PersistenceStoring
      Parameters:
      instance - the root instance of the subgraph of required instances to be stored.
      Returns:
      the object id representing the passed instance.

    • storeAll

      long[] storeAll​(Object... instances)
      Convenience method to PersistenceStoring.store(Object) multiple instances. The passed array (maybe implicitely created by the compiler) itself is NOT stored.
      Specified by:
      storeAll in interface PersistenceStoring
      Parameters:
      instances - multiple root instances of the subgraphs of required instances to be stored.
      Returns:
      an array containing the object ids representing the passed instances.

    • storeAll

      void storeAll​(Iterable<?> instances)
      Convenience method to PersistenceStoring.store(Object) all instances of an Iterable type, usually a collection.
      The passed instance itself is NOT stored.
      Note that this method does not return an array of objectIds, since the amount of instances supplied by the passed Iterable cannot be known until after all instances have been stored and the memory and performance overhead to collect them dynamically would not be worth it in most cases since the returned array is hardly ever needed. If it should be needed, the desired behavior can be easily achieved with a tiny custom-made utility method.
      Specified by:
      storeAll in interface PersistenceStoring
      Parameters:
      instances - multiple root instances of the subgraphs of required instances to be stored.

    • createLazyStorer

      Storer createLazyStorer()
      Creates a new Storer instance with lazy storing behavior. This means an entity instance encountered while traversing the entity graph is only stored if it is not yet known to the persistence context, i.e. does not have an objectId associated with it in the persistence context's PersistenceObjectRegistry.
      Returns:
      the newly created Storer instance.

    • createStorer

      Storer createStorer()
      Creates a new Storer instance with default storing behavior. The default is lazy storing. See createLazyStorer().
      Returns:
      the newly created Storer instance.

    • createEagerStorer

      Storer createEagerStorer()
      Creates a new Storer instance with eager storing behavior. This means an entity instance encountered while traversing the entity graph is always stored, regardless of if it is already known to the persistence context or not, i.e. does have an objectId associated with it in the persistence context's PersistenceObjectRegistry.

      Note: Eager storing is a dangerous behavior since - depending on the entity graph's referential layout - it can cause the whole entity graph present in the heap to be stored. Therefore, it is stronly advised to instead use lazy storing logic (see createLazyStorer()) or some other kind of limiting storing logic.

      Returns:
      the newly created Storer instance.