Roadmap

Development notes for pending tasks.

Version 2.0

A major revision that includes API incompatible changes.

• RemovalListener
  • Use friendlier typed lambda syntax to chain as (k, v, cause) -> ...
  • RemovalNotification retained as helper, but not used in the API
• AsyncLocalCache
  • Consider extending Cache<K, CompletableFuture<V>> interface
    • Cache: Conflict on get(k, k -> v) with get(k, k -> future)
    • LoadingCache: Conflicts on getAll returning future<map> vs map<k, future>
  • Add asMap() view of key -> futures
• Tracing
  • Remove deprecated methods
  • Use snake case for system properties (consistency with Typesafe Config library)

Pending

• Add CacheWriter
  • Simplifies support for write-through / write-behind caching, e.g. layered caches
  • Executed synchronously within atomic block that writes/deletes the cache entry
• JCache eviction listener ordering
  • Spec says that listeners must be notified in sequence of key operations
  • All implementations use asynchronous (unordered) notifications on eviction
  • Implement race handling to delay a events until the preceding evict is sent
• Ticker should only be read from when needed
  • The ticker is enabled if either statistics, expiration, or refresh are enabled
  • This causes the current time to be read for no-op calls, e.g. disabled expiration
  • On some operating systems this can significantly degrade performance (Mac, Windows)
• Reduce excessive padding
  • Currently copy-and-pasted for quick development
  • Uses 128-byte padding to protect from adjacent fields
• Rename SerializationAwareCopyStrategy to JavaSerializationCopyStrategy

Code Review

• Expired entries (eligible but not evicted)
  • Do all map methods screen and behave as if no entry exists?
  • Are the statistics recorded as a miss?
• Reference collected values (eligible but not evicted)
  • Do all map methods screen and behave as if no entry exists?
  • Are the statistics recorded as a miss?
• Removal listener notification
  • Is the listener notified after the operation completes?
  • Is the listener sent the correct notification?

Future

• Collections
  • Lazy MPMC linked queue
  • MPSC linked array queue [slides]
• Simulator
  • Add weight and expiration support
  • Advanced eviction policies
    • 2Q and OpenBSD's adaption
    • LIRS
    • Clock-Pro
    • TinyLFU