Interface FunctionalMap<K,​V>

  • All Superinterfaces:
    All Known Subinterfaces:
    FunctionalMap.ReadOnlyMap<K,​V>, FunctionalMap.ReadWriteMap<K,​V>, FunctionalMap.WriteOnlyMap<K,​V>

    public interface FunctionalMap<K,​V>
    extends java.lang.AutoCloseable
    Top level functional map interface offering common functionality for the read-only, read-write, and write-only operations that can be run against a functional map asynchronously.

    Lambdas passed in as parameters to functional map methods define the type of operation that is executed, but since lambdas are transparent to the internal logic, it was decided to separate the API into three types of operation: read-only, write-only, and read-write. This separation helps the user understand the group of functions and their possibilities.

    This conscious decision to separate read-only, write-only and read-write interfaces helps type safety. So, if a user gets a read-only map, it can't write to it by mistake since no such APIs are exposed. The same happens with write-only maps, the user can only write and cannot make the mistake of reading from the entry view because read operations are not exposed.

    Lambdas passed in to read-write and write-only operations, when running in a cluster, must be marshallable. One option to do so is to mark them as being Serializable but this is expensive in terms of payload size. Alternatively, you can provide an Infinispan Externalizer for it which drastically reduces the payload size. Marshallable lambdas for some of the most popular lambda functions used by ConcurrentMap and javax.cache.Cache are available via the MarshallableFunctions helper class.

    Being an asynchronous API, all methods that return a single result, return a CompletableFuture which wraps the result. To avoid blocking, it offers the possibility to receive callbacks when the CompletableFuture has completed, or it can be chained or composes with other CompletableFuture instances.

    For those operations that return multiple results, the API returns instances of a Traversable interface which offers a lazy pull­style API for working with multiple results. Although push­style interfaces for handling multiple results, such as RxJava, are fully asynchronous, they're harder to use from a user’s perspective. Traversable,​ being a lazy pull­style API, can still be asynchronous underneath since the user can decide to work on the Traversable at a later stage, and the implementation itself can decide when to compute those results.

    • Method Detail

      • withParams

        FunctionalMap<K,​V> withParams​(Param<?>... ps)
        Tweak functional map executions providing Param instances.
      • getName

        java.lang.String getName()
        Functional map's name.
      • isEncoded

        default boolean isEncoded()
        Tells if the underlying cache is using encoding or not
        true if the underlying cache is encoded