Package org.eclipse.persistence.sessions.interceptors

Class CacheInterceptor

java.lang.Object
org.eclipse.persistence.sessions.interceptors.CacheInterceptor
All Implemented Interfaces:
Cloneable, org.eclipse.persistence.internal.identitymaps.IdentityMap
public abstract class CacheInterceptor extends Object implements org.eclipse.persistence.internal.identitymaps.IdentityMap

Purpose: Define a class through which Cache access can be intercepted.

Description: EclipseLink makes extensive use of caching functionality. This class provides the mechanism for intercepting the cache access. Once intercepted applications can allow the process to continue by calling the method on the class attribute targetIdentityMap as described in the API javadocs or redirect the process entirely. * As with IdentityMaps an entire class inheritance hierarchy will share the same interceptor.

To implement a CacheInterceptor users should subclass this class implementing those methods they wish to intercept.

Configuration: Interceptors may be added to a session by using a Session or Descriptor customizer to set the class name of the interceptor on the target ClassDescriptor through the method setCacheInterceptorClass(Class).

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected org.eclipse.persistence.internal.sessions.AbstractSession
    interceptedSession
     
    protected org.eclipse.persistence.internal.identitymaps.IdentityMap
    targetIdentityMap
    This attribute stores the actual IdentityMap as configured by the user.

  • Constructor Summary

    Constructors
    Constructor
    Description
    CacheInterceptor(org.eclipse.persistence.internal.identitymaps.IdentityMap targetIdentityMap, org.eclipse.persistence.internal.sessions.AbstractSession interceptedSession)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    org.eclipse.persistence.internal.identitymaps.CacheKey
    acquireDeferredLock(Object primaryKey, boolean isCacheCheckComplete)
    Acquire a deferred lock on the object.
    org.eclipse.persistence.internal.identitymaps.CacheKey
    acquireLock(Object primaryKey, boolean forMerge, boolean isCacheCheckComplete)
    Acquire an active lock on the object.
    org.eclipse.persistence.internal.identitymaps.CacheKey
    acquireLockNoWait(Object primaryKey, boolean forMerge)
    Acquire an active lock on the object, if not already locked.
    org.eclipse.persistence.internal.identitymaps.CacheKey
    acquireLockWithWait(Object primaryKey, boolean forMerge, int wait)
    Acquire an active lock on the object, if not already locked.
    org.eclipse.persistence.internal.identitymaps.CacheKey
    acquireReadLockOnCacheKey(Object primaryKey)
    Acquire a read lock on the object.
    org.eclipse.persistence.internal.identitymaps.CacheKey
    acquireReadLockOnCacheKeyNoWait(Object primaryKey)
    Acquire a read lock on the object, if not already locked.
    abstract Object
    clone()
    Clone the map and all of the CacheKeys.
    Enumeration<org.eclipse.persistence.internal.identitymaps.CacheKey>
    cloneKeys()
    Allow for the CacheKey elements to be iterated.
    void
    collectLocks(HashMap threadList)
    Add all locked CacheKeys to the map grouped by thread.
    boolean
    containsKey(Object primaryKey)
    Return true if an CacheKey with the primary key is in the map.
    protected abstract CacheKeyInterceptor
    createCacheKeyInterceptor(org.eclipse.persistence.internal.identitymaps.CacheKey wrappedCacheKey)
     
    Enumeration
    elements()
    Allow for the cache to be iterated on.
    Object
    get(Object primaryKey)
    Return the object cached in the identity map or null if it could not be found.
    abstract Map<Object,org.eclipse.persistence.internal.identitymaps.CacheKey>
    getAllCacheKeysFromIdentityMapWithEntityPK(Object[] pkList, ClassDescriptor descriptor, org.eclipse.persistence.internal.sessions.AbstractSession session)
    ADVANCED: Using a list of Entity PK this method will attempt to bulk load the entire list from the cache.
    abstract Map<Object,Object>
    getAllFromIdentityMapWithEntityPK(Object[] pkList, ClassDescriptor descriptor, org.eclipse.persistence.internal.sessions.AbstractSession session)
    ADVANCED: Using a list of Entity PK this method will attempt to bulk load the entire list from the cache.
    org.eclipse.persistence.internal.identitymaps.CacheKey
    getCacheKey(Object primaryKey, boolean forMerge)
    Get the cache key (with object) for the primary key.
    org.eclipse.persistence.internal.identitymaps.CacheKey
    getCacheKeyForLock(Object primaryKey)
    Get the cache key (with object) for the primary key.
    ClassDescriptor
    getDescriptor()
    Return the descriptor that this is the map for.
    Class
    getDescriptorClass()
    Return the class that this is the map for.
    int
    getMaxSize()
     
    int
    getSize()
    Return the number of CacheKeys in the IdentityMap.
    int
    getSize(Class myClass, boolean recurse)
    Return the number of actual objects of type myClass in the IdentityMap.
    org.eclipse.persistence.internal.identitymaps.IdentityMap
    getTargetIdenttyMap()
    Return the instance of the IdentityMap that this intercpetor is wrapping.
    Object
    getWrapper(Object primaryKey)
    Get the wrapper object from the cache key associated with the given primary key, this is used for EJB2.
    Object
    getWriteLockValue(Object primaryKey)
    Get the write lock value from the cache key associated to the primarykey.
    Enumeration<org.eclipse.persistence.internal.identitymaps.CacheKey>
    keys()
    Allow for the CacheKey elements to be iterated.
    Enumeration<org.eclipse.persistence.internal.identitymaps.CacheKey>
    keys(boolean checkReadLocks)
    Allow for the CacheKey elements to be iterated.
    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
    org.eclipse.persistence.internal.identitymaps.CacheKey
    put(Object primaryKey, Object object, Object writeLockValue, long readTime)
    Store the object in the cache at its primary key.
    Object
    remove(Object primaryKey, Object object)
    Remove the CacheKey with the primaryKey from the map.
    Object
    remove(org.eclipse.persistence.internal.identitymaps.CacheKey cacheKey)
    Remove the CacheKey from the map.
    void
    setDescriptor(ClassDescriptor descriptor)
    Set the descriptor that this is the map for.
    void
    setWrapper(Object primaryKey, Object wrapper)
    Update the wrapper object in the CacheKey associated with the given primaryKey, this is used for EJB2.
    void
    setWriteLockValue(Object primaryKey, Object writeLockValue)
    Update the write lock value of the CacheKey associated with the given primaryKey.
    String
    toString()
     
    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.

    Methods inherited from class java.lang.Object

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

    Methods inherited from interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    release

  • Field Details

    • targetIdentityMap

      protected org.eclipse.persistence.internal.identitymaps.IdentityMap targetIdentityMap
      This attribute stores the actual IdentityMap as configured by the user.

    • interceptedSession

      protected org.eclipse.persistence.internal.sessions.AbstractSession interceptedSession

  • Constructor Details

    • CacheInterceptor

      public CacheInterceptor(org.eclipse.persistence.internal.identitymaps.IdentityMap targetIdentityMap, org.eclipse.persistence.internal.sessions.AbstractSession interceptedSession)

  • Method Details

    • acquireDeferredLock

      public org.eclipse.persistence.internal.identitymaps.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.
      Specified by:
      acquireDeferredLock in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • acquireLock

      public org.eclipse.persistence.internal.identitymaps.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.
      Specified by:
      acquireLock in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • acquireLockNoWait

      public org.eclipse.persistence.internal.identitymaps.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.
      Specified by:
      acquireLockNoWait in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • acquireLockWithWait

      public org.eclipse.persistence.internal.identitymaps.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.
      Specified by:
      acquireLockWithWait in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • acquireReadLockOnCacheKey

      public org.eclipse.persistence.internal.identitymaps.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.
      Specified by:
      acquireReadLockOnCacheKey in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • acquireReadLockOnCacheKeyNoWait

      public org.eclipse.persistence.internal.identitymaps.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.
      Specified by:
      acquireReadLockOnCacheKeyNoWait in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • collectLocks

      public void collectLocks(HashMap threadList)
      Add all locked CacheKeys to the map grouped by thread. Used to print all the locks in the identity map.
      Specified by:
      collectLocks in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • clone

      public abstract 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.
      Specified by:
      clone in interface org.eclipse.persistence.internal.identitymaps.IdentityMap
      Overrides:
      clone in class Object

    • containsKey

      public boolean containsKey(Object primaryKey)
      Return true if an CacheKey with the primary key is in the map. User API.
      Specified by:
      containsKey in interface org.eclipse.persistence.internal.identitymaps.IdentityMap
      Parameters:
      primaryKey - is the primary key for the object to search for.

    • createCacheKeyInterceptor

      protected abstract CacheKeyInterceptor createCacheKeyInterceptor(org.eclipse.persistence.internal.identitymaps.CacheKey wrappedCacheKey)

    • elements

      public Enumeration elements()
      Allow for the cache to be iterated on. This method is only used during debugging when validateCache() has been called to print out the contents of the cache.
      Specified by:
      elements in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • get

      public Object get(Object primaryKey)
      Return the object cached in the identity map or null if it could not be found. User API.
      Specified by:
      get in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • getAllFromIdentityMapWithEntityPK

      public abstract Map<Object,Object> getAllFromIdentityMapWithEntityPK(Object[] pkList, ClassDescriptor descriptor, org.eclipse.persistence.internal.sessions.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.
      Specified by:
      getAllFromIdentityMapWithEntityPK in interface org.eclipse.persistence.internal.identitymaps.IdentityMap
      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
      Throws:
      QueryException

    • getAllCacheKeysFromIdentityMapWithEntityPK

      public abstract Map<Object,org.eclipse.persistence.internal.identitymaps.CacheKey> getAllCacheKeysFromIdentityMapWithEntityPK(Object[] pkList, ClassDescriptor descriptor, org.eclipse.persistence.internal.sessions.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.
      Specified by:
      getAllCacheKeysFromIdentityMapWithEntityPK in interface org.eclipse.persistence.internal.identitymaps.IdentityMap
      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
      Throws:
      QueryException

    • getCacheKey

      public org.eclipse.persistence.internal.identitymaps.CacheKey getCacheKey(Object primaryKey, boolean forMerge)
      Get the cache key (with object) for the primary key.
      Specified by:
      getCacheKey in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • getCacheKeyForLock

      public org.eclipse.persistence.internal.identitymaps.CacheKey getCacheKeyForLock(Object primaryKey)
      Get the cache key (with object) for the primary key.
      Specified by:
      getCacheKeyForLock in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • getDescriptor

      public ClassDescriptor getDescriptor()
      Return the descriptor that this is the map for.
      Specified by:
      getDescriptor in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • getDescriptorClass

      public Class getDescriptorClass()
      Return the class that this is the map for.
      Specified by:
      getDescriptorClass in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • getMaxSize

      public int getMaxSize()
      Specified by:
      getMaxSize in interface org.eclipse.persistence.internal.identitymaps.IdentityMap
      Returns:
      The maxSize for the IdentityMap (NOTE: some subclasses may use this differently).

    • getSize

      public int getSize()
      Return the number of CacheKeys in the IdentityMap. This may contain weak referenced objects that have been garbage collected.
      Specified by:
      getSize in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • getSize

      public 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.
      Specified by:
      getSize in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • getTargetIdenttyMap

      public org.eclipse.persistence.internal.identitymaps.IdentityMap getTargetIdenttyMap()
      Return the instance of the IdentityMap that this intercpetor is wrapping. Any call that is to be passed on to the underlying EclipseLink cache should be passed to this IdentityMap.

    • getWrapper

      public Object getWrapper(Object primaryKey)
      Get the wrapper object from the cache key associated with the given primary key, this is used for EJB2.
      Specified by:
      getWrapper in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • getWriteLockValue

      public Object getWriteLockValue(Object primaryKey)
      Get the write lock value from the cache key associated to the primarykey. User API.
      Specified by:
      getWriteLockValue in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • keys

      public Enumeration<org.eclipse.persistence.internal.identitymaps.CacheKey> keys()
      Allow for the CacheKey elements to be iterated. CacheKey Collection is reused so this iteration may not be thread safe.
      Specified by:
      keys in interface org.eclipse.persistence.internal.identitymaps.IdentityMap
      Returns:
      Enumeration of CacheKey instances.

    • cloneKeys

      public Enumeration<org.eclipse.persistence.internal.identitymaps.CacheKey> cloneKeys()
      Allow for the CacheKey elements to be iterated. Clone of CacheKey Collection is returned so this iteration should be thread safe.
      Specified by:
      cloneKeys in interface org.eclipse.persistence.internal.identitymaps.IdentityMap
      Returns:
      Enumeration with clone of the CacheKey Collection

    • keys

      public Enumeration<org.eclipse.persistence.internal.identitymaps.CacheKey> keys(boolean checkReadLocks)
      Allow for the CacheKey elements to be iterated. CacheKey Collection is reused so this iteration may not be thread safe.
      Specified by:
      keys in interface org.eclipse.persistence.internal.identitymaps.IdentityMap
      Parameters:
      checkReadLocks - value of true if read lock on the CacheKey instances should be checked or false otherwise
      Returns:
      Enumeration of CacheKey instances.

    • lazyRelationshipLoaded

      public 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
      Specified by:
      lazyRelationshipLoaded in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • put

      public org.eclipse.persistence.internal.identitymaps.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.
      Specified by:
      put in interface org.eclipse.persistence.internal.identitymaps.IdentityMap
      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.

    • remove

      public 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.
      Specified by:
      remove in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • remove

      public Object remove(org.eclipse.persistence.internal.identitymaps.CacheKey cacheKey)
      Remove the CacheKey from the map.
      Specified by:
      remove in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • updateMaxSize

      public 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.
      Specified by:
      updateMaxSize in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • setDescriptor

      public void setDescriptor(ClassDescriptor descriptor)
      Set the descriptor that this is the map for.
      Specified by:
      setDescriptor in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • setWrapper

      public void setWrapper(Object primaryKey, Object wrapper)
      Update the wrapper object in the CacheKey associated with the given primaryKey, this is used for EJB2.
      Specified by:
      setWrapper in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • setWriteLockValue

      public 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.
      Specified by:
      setWriteLockValue in interface org.eclipse.persistence.internal.identitymaps.IdentityMap

    • toString

      public String toString()
      Specified by:
      toString in interface org.eclipse.persistence.internal.identitymaps.IdentityMap
      Overrides:
      toString in class Object