cache2k version 0.27-BETA “Fort Lauderdale”

New and Noteworthy

A lot of API movement, since we work towards 1.0. See Potential breakages and API changes. The API is not completely stable yet, but almost.

• Use of Java 8 features (StampedLock), when available, to improve performance of cache mutations
• Eviction allows segmentation, to improve multi core performance of insert and remove operations on the cache (Cache2kBuilder.evictionSegmentCount)
• Various other performance improvements
• Lots of work on the documentation. Not yet published. See the GitHub source

Potential breakages

Changes in semantics or API that may break existing applications are listed here. Modifications in the statistics output will not listed as breakage.

• null values are not allowed (any more!) by default. The use of a null value can be enabled again via permitNullValues. The old deprecated builder (CacheBuilder) configures the cache to permit null values by default to be backwards compatible to applications still using the version 0.20-ish interfaces.
• LoadCompletedListener renamed to CacheOperationCompletionListener
• Cache.load and Cache.reload: Signature change, swap the two parameters
• Cache.invoke and Cache.invokeAll: Remove var arg argument for arbitrary objects. Better aligned to Java 8 lambdas.

Bug fixes

If something is listed here it might affect an existing application and updating is recommended.

Fixes and Improvements

• getAll() returns a stable map, not affected by expiry and parallel cache modifications.
• Fixed possible inconsistency between CacheEntry.getValue() and CacheEntry.getLastModification(), when concurrent update happens
• Eviction implementation cleanup and simplification
• JCache: Custom classloader used for serialization of keys and values
• JCache: improved performance when not using custom expiry policy
• JCache: extended configuration of cache2k features via JCache is possible
• Exceptions in the expiry policy and resilience policy will be propagated as CacheLoaderException if happened during load
• asMap() provided ConcurrentMap interface view of the cache
• Reduce memory footprint: history size of Clock-Pro eviction reduced to one half of the capacity
• getAll() returns empty map if no loader is defined and requested keys are not in cache
• get() return null if no loader is defined and entry is not in cache (was exception before).
• CacheEntry.getValue() and MutableCacheEntry.getValue() throws exception if loader exception happened
• Cache.invoke: Exceptions from entry processor propagated correctly as EntryProcessingException
• Global ExceptionPropagator customizable via tunable mechanism.
• CacheEntryProcessor renamed to EntryProcessor
• CacheEntryProcessingException renamed to EntryProcessingException
• Cache2kBuilder.keepDataAfterExpired: has become false by default
• EntryProcessor: Triggers load when MutableEntry.getException is called
• EntryProcessor: MutableEntry.setException or MutableEntry.setExpiry work correctly after loading the value
• Statistics: Correct usage counter in case of a race at entry mutation
• new Cache2kBuilder(){}, yields proper exception instead of just ClassCastException
• new Cache2kBuilder<Object, Object>(){}, yields IllegalArgumentException, use Cache2kBuilder.forUnkownTypes()
• lots of internal cleanup
• Interface ExpiryTimeValues with constants for special expiry times

API Changes and new methods

• contains() replaced with containsKey()
• expire() expires an entry manually or resets the expiry time
• Rename:CacheConfiguration to Cache2kConfiguration
• Removed clearTimingStatistics operation from JMX
• Cache.iterator() is deprecated, alternative is Cache.entries() or Cache.keys()
• Cache.invoke and Cache.invokeAll: Remove var arg argument for arbitrary objects. Better aligned to Java 8 lambdas.

Using this cache2k version

    <dependency>
      <groupId>org.cache2k</groupId>
      <artifactId>cache2k-api</artifactId>
      <version>0.27-BETA</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.cache2k</groupId>
      <artifactId>cache2k-all</artifactId>
      <version>0.27-BETA</version>
      <scope>runtime</scope>
    </dependency>

    <dependency>
      <groupId>org.cache2k</groupId>
      <artifactId>cache2k-api</artifactId>
      <version>0.27-BETA</version>
    </dependency>
    <dependency>
      <groupId>org.cache2k</groupId>
      <artifactId>cache2k-core</artifactId>
      <version>0.27-BETA</version>
      <scope>runtime</scope>
    </dependency>

    <dependency>
      <groupId>org.cache2k</groupId>
      <artifactId>cache2k-jcache</artifactId>
      <version>0.27-BETA</version>
    </dependency>
    <dependency>
      <groupId>javax.cache</groupId>
      <artifactId>cache-api</artifactId>
      <version>1.0.0</version>
    </dependency>