Module org.eclipse.persistence.core
Package org.eclipse.persistence.internal.identitymaps

Interface IdentityMap

All Superinterfaces:
Cloneable
All Known Implementing Classes:
AbstractIdentityMap, CacheIdentityMap, CacheInterceptor, FullIdentityMap, HardCacheWeakIdentityMap, NoIdentityMap, SoftCacheWeakIdentityMap, SoftIdentityMap, UnitOfWorkIdentityMap, WeakIdentityMap, WeakUnitOfWorkIdentityMap
public interface IdentityMap extends Cloneable

Purpose: Provides the interface for IdentityMap interaction.

Responsibilities: Provides access to all of the public interface for the EclipseLink IdentityMaps. This interface can be used if implementing custom identity maps that are radically different than the stock IdentityMaps otherwise simply extending the appropriate IdentityMap implementation is the best approach.

Since:
EclipseLink 1.0M7
See Also:

  • Method Details

    • acquireDeferredLock

      CacheKey acquireDeferredLock(Object primaryKey, boolean isCacheCheckComplete)
      Acquire a deferred lock on the object. This is used while reading if the object has relationships without indirection. This first thread will get an active lock. Other threads will get deferred locks, all threads will wait until all other threads are complete before releasing their locks.

    • acquireLock

      CacheKey acquireLock(Object primaryKey, boolean forMerge, boolean isCacheCheckComplete)
      Acquire an active lock on the object. This is used by reading (when using indirection or no relationships) and by merge.

    • acquireLockNoWait

      CacheKey acquireLockNoWait(Object primaryKey, boolean forMerge)
      Acquire an active lock on the object, if not already locked. This is used by merge for missing existing objects.

    • acquireLockWithWait

      CacheKey acquireLockWithWait(Object primaryKey, boolean forMerge, int wait)
      Acquire an active lock on the object, if not already locked. This is used by merge for missing existing objects.

    • acquireReadLockOnCacheKey

      CacheKey acquireReadLockOnCacheKey(Object primaryKey)
      Acquire a read lock on the object. This is used by UnitOfWork cloning. This will allow multiple users to read the same object but prevent writes to the object while the read lock is held.

    • acquireReadLockOnCacheKeyNoWait

      CacheKey acquireReadLockOnCacheKeyNoWait(Object primaryKey)
      Acquire a read lock on the object, if not already locked. This is used by UnitOfWork cloning. This will allow multiple users to read the same object but prevent writes to the object while the read lock is held.

    • clone

      Object clone()
      Clone the map and all of the CacheKeys. This is used by UnitOfWork commitAndResumeOnFailure to avoid corrupting the cache during a failed commit.

    • collectLocks

      void collectLocks(HashMap threadList)
      Add all locked CacheKeys to the map grouped by thread. Used to print all the locks in the identity map.

    • containsKey

      boolean containsKey(Object primaryKey)
      Return true if an CacheKey with the primary key is in the map. User API.
      Parameters:
      primaryKey - is the primary key for the object to search for.

    • elements

      Enumeration elements()
      Allow for the cache to be iterated on.

    • get

      Object get(Object primaryKey)
      Return the object cached in the identity map or null if it could not be found. User API.

    • getAllFromIdentityMapWithEntityPK

      Map<Object,Object> getAllFromIdentityMapWithEntityPK(Object[] pkList, ClassDescriptor descriptor, AbstractSession session)
      ADVANCED: Using a list of Entity PK this method will attempt to bulk load the entire list from the cache. In certain circumstances this can have large performance improvements over loading each item individually.
      Parameters:
      pkList - List of Entity PKs to extract from the cache
      descriptor - Descriptor type to be retrieved.
      Returns:
      Map of Entity PKs associated to the Entities that were retrieved

    • getAllCacheKeysFromIdentityMapWithEntityPK

      Map<Object,CacheKey> getAllCacheKeysFromIdentityMapWithEntityPK(Object[] pkList, ClassDescriptor descriptor, AbstractSession session)
      ADVANCED: Using a list of Entity PK this method will attempt to bulk load the entire list from the cache. In certain circumstances this can have large performance improvements over loading each item individually.
      Parameters:
      pkList - List of Entity PKs to extract from the cache
      descriptor - Descriptor type to be retrieved.
      Returns:
      Map of Entity PKs associated to the Entities that were retrieved

    • getCacheKey

      CacheKey getCacheKey(Object primaryKey, boolean forMerge)
      Get the cache key (with object) for the primary key.

    • getCacheKeyForLock

      CacheKey getCacheKeyForLock(Object primaryKey)
      Get the cache key (with object) for the primary key in order to acquire a lock.

    • getDescriptorClass

      Class<?> getDescriptorClass()
      Return the class that this is the map for.

    • getDescriptor

      ClassDescriptor getDescriptor()
      Return the descriptor that this is the map for.

    • getMaxSize

      int getMaxSize()
      Returns:
      The maxSize for the IdentityMap (NOTE: some subclasses may use this differently).

    • getSize

      int getSize()
      Return the number of CacheKeys in the IdentityMap. This may contain weak referenced objects that have been garbage collected.

    • getSize

      int getSize(Class<?> myClass, boolean recurse)
      Return the number of actual objects of type myClass in the IdentityMap. Recurse = true will include subclasses of myClass in the count.

    • getWrapper

      Object getWrapper(Object primaryKey)
      Get the wrapper object from the cache key associated with the given primary key, this is used for EJB2.

    • getWriteLockValue

      Object getWriteLockValue(Object primaryKey)
      Get the write lock value from the cache key associated to the primarykey. User API.

    • keys

      Enumeration<CacheKey> keys()
      Allow for the CacheKeys to be iterated on. Read locks should be checked

    • cloneKeys

      Enumeration<CacheKey> cloneKeys()
      Allow for the CacheKeys to be iterated on using copy of keys enumeration. This is thread safe access to keys.
      Returns:
      clone of the CacheKeys enumeration

    • keys

      Enumeration<CacheKey> keys(boolean checkReadLocks)
      Allow for the CacheKeys to be iterated on.
      Parameters:
      checkReadLocks - - true if readLocks should be checked, false otherwise.

    • lazyRelationshipLoaded

      void lazyRelationshipLoaded(Object rootEntity, ValueHolderInterface valueHolder, ForeignReferenceMapping mapping)
      Notify the cache that a lazy relationship has been triggered in the object and the cache may need to be updated

    • put

      CacheKey put(Object primaryKey, Object object, Object writeLockValue, long readTime)
      Store the object in the cache at its primary key. This is used by InsertObjectQuery, typically into the UnitOfWork identity map. Merge and reads do not use put, but acquireLock. Also an advanced (very) user API.
      Parameters:
      primaryKey - is the primary key for the object.
      object - is the domain object to cache.
      writeLockValue - is the current write lock value of object, if null the version is ignored.

    • release

      void release()
      This method may be called during initialize all identity maps. It allows the identity map or interceptor the opportunity to release any resources before being thrown away.

    • remove

      Object remove(Object primaryKey, Object object)
      Remove the CacheKey with the primaryKey from the map. This is used by DeleteObjectQuery and merge. This is also an advanced (very) user API.

    • remove

      Object remove(CacheKey cacheKey)
      Remove the CacheKey from the map.

    • updateMaxSize

      void updateMaxSize(int maxSize)
      This method will be used to update the max cache size, any objects exceeding the max cache size will be remove from the cache. Please note that this does not remove the object from the identityMap, except in the case of the CacheIdentityMap.

    • setDescriptor

      void setDescriptor(ClassDescriptor descriptor)
      Set the descriptor that this is the map for.

    • setWrapper

      void setWrapper(Object primaryKey, Object wrapper)
      Update the wrapper object in the CacheKey associated with the given primaryKey, this is used for EJB2.

    • setWriteLockValue

      void setWriteLockValue(Object primaryKey, Object writeLockValue)
      Update the write lock value of the CacheKey associated with the given primaryKey. This is used by UpdateObjectQuery, and is also an advanced (very) user API.

    • toString

      String toString()
      Overrides:
      toString in class Object