## org.hibernate.cache
Interface OptimisticCache

All Superinterfaces:
  Cache

    public interface OptimisticCache

extends Cache

A contract for transactional cache implementations which support optimistic locking of items within the cache.

The optimisitic locking capabilities are only utilized for the entity cache regions.

Unlike the methods on the `Cache` interface, all the methods here will only ever be called from access scenarios where versioned data is actually a possiblity (i.e., entity data). Be sure to consult with `OptimisticCacheSource.isVersioned()` to determine whether versioning is actually in effect.

Author:
  Steve Ebersole

Method Summary
`void` `setSource(OptimisticCacheSource source)` Indicates the "source" of the cached data.
`void` `writeInsert(Object key, Object value, Object currentVersion)` Called during `CacheConcurrencyStrategy.insert(java.lang.Object, java.lang.Object, java.lang.Object)` processing for transactional strategies.
`void` `writeLoad(Object key, Object value, Object currentVersion)` Called during `CacheConcurrencyStrategy.put(java.lang.Object, java.lang.Object, long, java.lang.Object, java.util.Comparator, boolean)` processing for transactional strategies.
`void` `writeUpdate(Object key, Object value, Object currentVersion, Object previousVersion)` Called during `CacheConcurrencyStrategy.update(java.lang.Object, java.lang.Object, java.lang.Object, java.lang.Object)` processing for transactional strategies.

Methods inherited from interface org.hibernate.cache.Cache
`clear, destroy, get, getElementCountInMemory, getElementCountOnDisk, getRegionName, getSizeInMemory, getTimeout, lock, nextTimestamp, put, read, remove, toMap, unlock, update`

Method Detail

### setSource

    void setSource(OptimisticCacheSource source)

  Indicates the "source" of the cached data. Currently this will only ever represent an `EntityPersister`.

  Made available to the cache so that it can access certain information about versioning strategy.

  Parameters:
    `source` - The source.

### writeInsert

    void writeInsert(Object key,
                     Object value,
                     Object currentVersion)

  Called during `CacheConcurrencyStrategy.insert(java.lang.Object, java.lang.Object, java.lang.Object)` processing for transactional strategies. Indicates we have just performed an insert into the DB and now need to cache that entity's data.

  Parameters:
    `key` - The cache key.
    `value` - The data to be cached.
    `currentVersion` - The entity's version; or null if not versioned.

### writeUpdate

    void writeUpdate(Object key,
                     Object value,
                     Object currentVersion,
                     Object previousVersion)

  Called during `CacheConcurrencyStrategy.update(java.lang.Object, java.lang.Object, java.lang.Object, java.lang.Object)` processing for transactional strategies. Indicates we have just performed an update against the DB and now need to cache the updated state.

  Parameters:
    `key` - The cache key.
    `value` - The data to be cached.
    `currentVersion` - The entity's current version
    `previousVersion` - The entity's previous version (before the update); or null if not versioned.

### writeLoad

    void writeLoad(Object key,
                   Object value,
                   Object currentVersion)

  Called during `CacheConcurrencyStrategy.put(java.lang.Object, java.lang.Object, long, java.lang.Object, java.util.Comparator, boolean)` processing for transactional strategies. Indicates we have just loaded an entity's state from the database and need it cached.

  Parameters:
    `key` - The cache key.
    `value` - The data to be cached.
    `currentVersion` - The entity's version; or null if not versioned.

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