Package org.camunda.bpm.engine.impl.db.entitymanager.cache

Class DbEntityCache

java.lang.Object
org.camunda.bpm.engine.impl.db.entitymanager.cache.DbEntityCache
public class DbEntityCache extends Object
A simple first level cache for Entities.
Author:
Daniel Meyer

  • Field Details

    • LOG

      protected static final EnginePersistenceLogger LOG

    • cachedEntites

      protected Map<Class<?>,Map<String,CachedDbEntity>> cachedEntites
      The cache itself: maps entity types (classes) to maps indexed by id (primary key). The motivation for indexing by type (class) is a) multiple entities of different types could have the same value as primary key. In the process engine, TaskEntity and HistoricTaskEntity have the same id value. b) performance (?)

    • cacheKeyMapping

      protected DbEntityCacheKeyMapping cacheKeyMapping

  • Constructor Details

    • DbEntityCache

      public DbEntityCache()

    • DbEntityCache

      public DbEntityCache(DbEntityCacheKeyMapping cacheKeyMapping)

  • Method Details

    • get

      public <T extends DbEntity> T get(Class<T> type, String id)
      get an object from the cache
      Parameters:
      type - the type of the object
      id - the id of the object
      Returns:
      the object or 'null' if the object is not in the cache
      Throws:
      ProcessEngineException - if an object for the given id can be found but is of the wrong type.

    • getEntitiesByType

      public <T extends DbEntity> List<T> getEntitiesByType(Class<T> type)

    • getCachedEntity

      public CachedDbEntity getCachedEntity(Class<?> type, String id)
      Looks up an entity in the cache.
      Parameters:
      type - the type of the object
      id - the id of the CachedEntity to lookup
      Returns:
      the cached entity or null if the entity does not exist.

    • getCachedEntity

      public CachedDbEntity getCachedEntity(DbEntity dbEntity)
      Looks up an entity in the cache.
      Parameters:
      dbEntity - the entity for which the CachedEntity should be looked up
      Returns:
      the cached entity or null if the entity does not exist.

    • putTransient

      public void putTransient(DbEntity e)
      Put a new, DbEntityState.TRANSIENT object into the cache.
      Parameters:
      e - the object to put into the cache

    • putPersistent

      public void putPersistent(DbEntity e)
      Put a DbEntityState.PERSISTENT object into the cache.
      Parameters:
      e - the object to put into the cache

    • putMerged

      public void putMerged(DbEntity e)
      Put a DbEntityState.MERGED object into the cache.
      Parameters:
      e - the object to put into the cache

    • putInternal

      protected void putInternal(CachedDbEntity entityToAdd)

    • remove

      public boolean remove(DbEntity e)
      Remove an entity from the cache
      Parameters:
      e - the entity to remove
      Returns:

    • remove

      public void remove(CachedDbEntity cachedDbEntity)
      Parameters:
      cachedDbEntity -

    • contains

      public boolean contains(DbEntity dbEntity)
      Allows checking whether the provided entity is present in the cache
      Parameters:
      dbEntity - the entity to check
      Returns:
      true if the the provided entity is present in the cache

    • isPersistent

      public boolean isPersistent(DbEntity dbEntity)
      Allows checking whether the provided entity is present in the cache and is DbEntityState.PERSISTENT.
      Parameters:
      dbEntity - the entity to check
      Returns:
      true if the provided entity is present in the cache and is DbEntityState.PERSISTENT.

    • isDeleted

      public boolean isDeleted(DbEntity dbEntity)
      Allows checking whether the provided entity is present in the cache and is marked to be deleted.
      Parameters:
      dbEntity - the entity to check
      Returns:
      true if the provided entity is present in the cache and is marked to be deleted

    • isTransient

      public boolean isTransient(DbEntity dbEntity)
      Allows checking whether the provided entity is present in the cache and is DbEntityState.TRANSIENT.
      Parameters:
      dbEntity - the entity to check
      Returns:
      true if the provided entity is present in the cache and is DbEntityState.TRANSIENT.

    • getCachedEntities

      public List<CachedDbEntity> getCachedEntities()

    • setDeleted

      public void setDeleted(DbEntity dbEntity)
      Sets an object to a deleted state. It will not be removed from the cache but transition to one of the DELETED states, depending on it's current state.
      Parameters:
      dbEntity - the object to mark deleted.

    • undoDelete

      public void undoDelete(DbEntity dbEntity)