Package org.hibernate.cache

Interface CacheConcurrencyStrategy

All Known Implementing Classes:

NonstrictReadWriteCache, ReadOnlyCache, ReadWriteCache, TransactionalCache

public interface CacheConcurrencyStrategy

Deprecated.

As of 3.3; see for details.

Implementors manage transactional access to cached data. Transactions pass in a timestamp indicating transaction start time. Two different implementation patterns are provided for.

• A transaction-aware cache implementation might be wrapped by a "synchronous" concurrency strategy, where updates to the cache are written to the cache inside the transaction.
• A non transaction-aware cache would be wrapped by an "asynchronous" concurrency strategy, where items are merely "soft locked" during the transaction and then updated during the "after transaction completion" phase; the soft lock is not an actual lock on the database row - only upon the cached representation of the item.

In terms of entity caches, the expected call sequences are:

• DELETES : lock(java.lang.Object, java.lang.Object) -> evict(java.lang.Object) -> release(java.lang.Object, org.hibernate.cache.access.SoftLock)
• UPDATES : lock(java.lang.Object, java.lang.Object) -> update(java.lang.Object, java.lang.Object, java.lang.Object, java.lang.Object) -> afterUpdate(java.lang.Object, java.lang.Object, java.lang.Object, org.hibernate.cache.access.SoftLock)
• INSERTS : insert(java.lang.Object, java.lang.Object, java.lang.Object) -> afterInsert(java.lang.Object, java.lang.Object, java.lang.Object)

In terms of collection caches, all modification actions actually just invalidate the entry(s). The call sequence here is: lock(java.lang.Object, java.lang.Object) -> evict(java.lang.Object) -> release(java.lang.Object, org.hibernate.cache.access.SoftLock)

Note that, for an asynchronous cache, cache invalidation must be a two step process (lock->release, or lock-afterUpdate), since this is the only way to guarantee consistency with the database for a nontransactional cache implementation. For a synchronous cache, cache invalidation is a single step process (evict, or update). Hence, this interface defines a three step process, to cater for both models.

Note that query result caching does not go through a concurrency strategy; they are managed directly against the underlying cache regions.

Method Summary

Modifier and Type	Method	Description
boolean	afterInsert(Object key, Object value, Object version)	Deprecated. Called after an item has been inserted (after the transaction completes), instead of calling release().
boolean	afterUpdate(Object key, Object value, Object version, SoftLock lock)	Deprecated. Called after an item has been updated (after the transaction completes), instead of calling release().
void	clear()	Deprecated. Evict all items from the cache immediately.
void	destroy()	Deprecated. Clean up all resources.
void	evict(Object key)	Deprecated. Called after an item has become stale (before the transaction completes).
Object	get(Object key, long txTimestamp)	Deprecated. Attempt to retrieve an object from the cache.
Cache	getCache()	Deprecated. Get the wrapped cache implementation
String	getRegionName()	Deprecated. Get the cache region name
boolean	insert(Object key, Object value, Object currentVersion)	Deprecated. Called after an item has been inserted (before the transaction completes), instead of calling evict().
SoftLock	lock(Object key, Object version)	Deprecated. We are going to attempt to update/delete the keyed object.
boolean	put(Object key, Object value, long txTimestamp, Object version, Comparator versionComparator, boolean minimalPut)	Deprecated. Attempt to cache an object, after loading from the database.
void	release(Object key, SoftLock lock)	Deprecated. Called when we have finished the attempted update/delete (which may or may not have been successful), after transaction completion.
void	remove(Object key)	Deprecated. Evict an item from the cache immediately (without regard for transaction isolation).
void	setCache(Cache cache)	Deprecated. Set the underlying cache implementation.
boolean	update(Object key, Object value, Object currentVersion, Object previousVersion)	Deprecated. Called after an item has been updated (before the transaction completes), instead of calling evict().

Method Details

get

Object get(Object key,
 long txTimestamp)
    throws CacheException

Deprecated.

Attempt to retrieve an object from the cache. Mainly used in attempting to resolve entities/collections from the second level cache.

Parameters:

key -

txTimestamp - a timestamp prior to the transaction start time

Returns:

the cached object or null

Throws:

CacheException

put

boolean put(Object key,
 Object value,
 long txTimestamp,
 Object version,
 Comparator versionComparator,
 boolean minimalPut)
     throws CacheException

Deprecated.

Attempt to cache an object, after loading from the database.

Parameters:

key -

value -

txTimestamp - a timestamp prior to the transaction start time

version - the item version number

versionComparator - a comparator used to compare version numbers

minimalPut - indicates that the cache should avoid a put is the item is already cached

Returns:

true if the object was successfully cached

Throws:

CacheException

lock

SoftLock lock(Object key,
 Object version)
       throws CacheException

Deprecated.

We are going to attempt to update/delete the keyed object. This method is used by "asynchronous" concurrency strategies.

The returned object must be passed back to release(), to release the lock. Concurrency strategies which do not support client-visible locks may silently return null.

Parameters:

key -

version -

Throws:

CacheException

evict

void evict(Object key)
    throws CacheException

Deprecated.

Called after an item has become stale (before the transaction completes). This method is used by "synchronous" concurrency strategies.

Throws:

CacheException

update

boolean update(Object key,
 Object value,
 Object currentVersion,
 Object previousVersion)
        throws CacheException

Deprecated.

Called after an item has been updated (before the transaction completes), instead of calling evict(). This method is used by "synchronous" concurrency strategies.

Throws:

CacheException

insert

boolean insert(Object key,
 Object value,
 Object currentVersion)
        throws CacheException

Deprecated.

Called after an item has been inserted (before the transaction completes), instead of calling evict(). This method is used by "synchronous" concurrency strategies.

Throws:

CacheException

release

void release(Object key,
 SoftLock lock)
      throws CacheException

Deprecated.

Called when we have finished the attempted update/delete (which may or may not have been successful), after transaction completion. This method is used by "asynchronous" concurrency strategies.

Parameters:

key -

Throws:

CacheException

afterUpdate

boolean afterUpdate(Object key,
 Object value,
 Object version,
 SoftLock lock)
             throws CacheException

Deprecated.

Called after an item has been updated (after the transaction completes), instead of calling release(). This method is used by "asynchronous" concurrency strategies.

Throws:

CacheException

afterInsert

boolean afterInsert(Object key,
 Object value,
 Object version)
             throws CacheException

Deprecated.

Called after an item has been inserted (after the transaction completes), instead of calling release(). This method is used by "asynchronous" concurrency strategies.

Throws:

CacheException

remove

void remove(Object key)
     throws CacheException

Deprecated.

Evict an item from the cache immediately (without regard for transaction isolation).

Parameters:

key -

Throws:

CacheException

clear

void clear()
    throws CacheException

Deprecated.

Evict all items from the cache immediately.

Throws:

CacheException

destroy

void destroy()

Deprecated.

Clean up all resources.

setCache

void setCache(Cache cache)

Deprecated.

Set the underlying cache implementation.

Parameters:

cache -

getRegionName

String getRegionName()

Deprecated.

Get the cache region name

getCache

Cache getCache()

Deprecated.

Get the wrapped cache implementation