Class SelectiveCache

java.lang.Object
io.fluxzero.sdk.persisting.caching.SelectiveCache
All Implemented Interfaces:
Cache
public class SelectiveCache extends Object implements Cache
A Cache implementation that partitions values across two internal caches based on a provided Predicate.

If a value matches the selector, it is stored in the delegate cache; otherwise, it is stored in the nextCache. This is particularly useful when certain types of objects (e.g., aggregates, projections) require specialized caching behavior while others do not.

Chaining: SelectiveCache instances can be chained by using another SelectiveCache as the nextCache. This enables complex multi-level cache routing logic, where each level applies a different selector to direct objects to a different backing cache.

Example use case: Route aggregates to one cache and all other entities to a fallback cache: 

Predicate<Object> aggregateSelector = SelectiveCache.aggregateSelector(MyAggregate.class);
Cache aggregateCache = new DefaultCache();
Cache fallbackCache = new DefaultCache();
Cache selectiveCache = new SelectiveCache(aggregateCache, aggregateSelector, fallbackCache);

  • Constructor Details

    • SelectiveCache

      public SelectiveCache(Cache nextCache, Predicate<Object> selector)
      Constructs a SelectiveCache with a default in-memory delegate cache.
      Parameters:
      nextCache - The fallback cache used when selector does not match a value
      selector - A predicate to decide which cache a value should go into

  • Method Details

    • aggregateSelector

      public static Predicate<Object> aggregateSelector(Class<?> type)
      Utility predicate to match aggregates of a given root type. This checks the type of the value inside an Entity, or the declared type if the value is null.

    • put

      public Object put(Object id, Object value)
      Description copied from interface: Cache
      Puts a value in the cache for the given id, overwriting any existing value.
      Specified by:
      put in interface Cache
      Parameters:
      id - the key with which the specified value is to be associated
      value - the value to be associated with the specified key
      Returns:
      the previous value associated with the id, or null if none

    • putIfAbsent

      public Object putIfAbsent(Object id, Object value)
      Description copied from interface: Cache
      Associates the specified value with the given id only if no value is currently associated.
      Specified by:
      putIfAbsent in interface Cache
      Parameters:
      id - the key to check for presence
      value - the value to associate if absent
      Returns:
      the existing value associated with the key, or null if the new value was successfully put

    • computeIfAbsent

      public <T> T computeIfAbsent(Object id, Function<? super Object, T> mappingFunction)
      Description copied from interface: Cache
      If a value is not already associated with the given id, computes and stores one using the given function.
      Specified by:
      computeIfAbsent in interface Cache
      Type Parameters:
      T - the expected type of the value
      Parameters:
      id - the key to check or compute
      mappingFunction - the function to compute a value if absent
      Returns:
      the current or newly computed value

    • computeIfPresent

      public <T> T computeIfPresent(Object id, BiFunction<? super Object, ? super T, ? extends T> mappingFunction)
      Description copied from interface: Cache
      If a value is already associated with the given id, computes a new value using the provided function and replaces the old one.
      Specified by:
      computeIfPresent in interface Cache
      Type Parameters:
      T - the expected type of the value
      Parameters:
      id - the key to compute for
      mappingFunction - the function to compute a new value from the current one
      Returns:
      the newly computed value, or null if the mapping function returned null

    • compute

      public <T> T compute(Object id, BiFunction<? super Object, ? super T, ? extends T> mappingFunction)
      Description copied from interface: Cache
      Computes and stores a new value for the given id using the provided function.

      The previous value (if any) is provided to the function. The result is stored in the cache.

      Specified by:
      compute in interface Cache
      Type Parameters:
      T - the expected type of the value
      Parameters:
      id - the key to compute for
      mappingFunction - the function to compute a new value
      Returns:
      the newly computed value, or null if the mapping function returned null

    • get

      public <T> T get(Object id)
      Description copied from interface: Cache
      Retrieves the value associated with the given id, or null if not found.
      Specified by:
      get in interface Cache
      Type Parameters:
      T - the expected type of the value
      Parameters:
      id - the key to retrieve
      Returns:
      the cached value, or null if absent

    • containsKey

      public boolean containsKey(Object id)
      Description copied from interface: Cache
      Checks whether the cache contains an entry for the given id.
      Specified by:
      containsKey in interface Cache
      Parameters:
      id - the key to check
      Returns:
      true if the key exists in the cache, false otherwise

    • remove

      public <T> T remove(Object id)
      Description copied from interface: Cache
      Removes the entry associated with the given id, if present.
      Specified by:
      remove in interface Cache
      Type Parameters:
      T - the expected type of the removed value
      Parameters:
      id - the key to remove
      Returns:
      the removed value, or null if no value was associated with the key

    • clear

      public void clear()
      Description copied from interface: Cache
      Removes all entries from the cache.
      Specified by:
      clear in interface Cache

    • modifyEach

      public <T> void modifyEach(BiFunction<? super Object, ? super T, ? extends T> modifierFunction)
      Description copied from interface: Cache
      Applies the given modifier function to all values currently in the cache.

      This is useful for bulk modifications, e.g. adjusting internal state after a system-wide change.

      Specified by:
      modifyEach in interface Cache
      Type Parameters:
      T - the expected type of the values
      Parameters:
      modifierFunction - the function to apply to each entry

    • size

      public int size()
      Description copied from interface: Cache
      Returns the number of entries currently stored in the cache.
      Specified by:
      size in interface Cache
      Returns:
      the number of entries

    • registerEvictionListener

      public Registration registerEvictionListener(Consumer<CacheEviction> listener)
      Description copied from interface: Cache
      Registers a listener to be notified whenever a cache entry is evicted or removed.
      Specified by:
      registerEvictionListener in interface Cache
      Parameters:
      listener - a function that consumes CacheEvictions
      Returns:
      a registration that can be used to cancel the listener

    • close

      public void close()
      Description copied from interface: Cache
      Closes the cache and releases all associated resources.
      Specified by:
      close in interface Cache