Package de.aristaflow.ilm.model.common.collection

Class AbstractIteratorHandler<T extends de.aristaflow.adept2.model.communication.ServerSideProxy,​I,​N>

  • Type Parameters:
    T - The type of the handled iterators.
    I - The type of the initial data provided when requesting the iterator.
    N - The type of the data when iterating.
    Direct Known Subclasses:
    IncWorklistHandler, IncWorklistUpdateHandler, RemoteIteratorHandler
    public class AbstractIteratorHandler<T extends de.aristaflow.adept2.model.communication.ServerSideProxy,​I,​N>
extends Object
    This class handles provides the basic means for handling iterators. This includes the data structure containing the iterators, runnables for removing iterators from the data structure and closing them as well as the corresponding scheduled executor service.

    Iterators and their handling classes are generic classes whereas the generic type specifies the elements of the iterator. However, Java's type system may become a problem for other languages. Therefore the ILM removes the generic type and makes it explicit. At runtime this handler needs to create and provide the concrete types without generics, so instantiation is delegated to suppliers provided when instantiating this handler.

    Due to the API of iterators being rather specific, this class is a mere sketch and a lot of logic has to happen in subclasses.

    See Also:
    RemoteIterator, IncrementalWorklist, IncrementalWorklistUpdate

    • Field Detail

      • logger

        protected final Logger logger
        The logger for logging problems, e. g. when implicitly closing after retrieving all data.

      • iteratorTypeName

        protected final String iteratorTypeName
        The name of the iterator type (for logging close problems).

      • iterators

        protected final Map<UUID,​T extends de.aristaflow.adept2.model.communication.ServerSideProxy> iterators
        The map containing iterators while they are active. The key is a random UUID identifying the iterator.
        The server-side proxies will either be explicitly closed, time out via removerService or being forcibly closed via running the remaining removers after shutting down the remover service.

      • removerService

        protected final LoggingScheduledThreadPoolExecutor removerService
        The scheduler service which closes and removes all registered iterators after their alive time has elapsed from this handler.

      • initDataCreator

        protected final Supplier<I> initDataCreator
        The creator for data provided initially when requesting the iterator.

      • dataCreator

        protected final Supplier<N> dataCreator
        The creator for data provided when iterating.

    • Constructor Detail

      • AbstractIteratorHandler

        @Deprecated(since="15.0.0",
            forRemoval=true)
public AbstractIteratorHandler​(Supplier<I> initDataCreator,
                               Supplier<N> dataCreator,
                               String name,
                               LogService logService)
        Deprecated, for removal: This API element is subject to removal in a future version.
        Use AbstractIteratorHandler(Supplier, Supplier, String, String, LogService) instead.
        Creates a new iteration handler.
        Parameters:
        initDataCreator - The creator for data provided initially when requesting the iterator.
        dataCreator - The creator for data provided when iterating.
        name - The name for the executor.
        logService - The log service to retrieve the logger for log messages from.

      • AbstractIteratorHandler

        public AbstractIteratorHandler​(Supplier<I> initDataCreator,
                               Supplier<N> dataCreator,
                               String iteratorTypeName,
                               String executorName,
                               LogService logService)
        Creates a new iteration handler.
        Parameters:
        initDataCreator - The creator for data provided initially when requesting the iterator.
        dataCreator - The creator for data provided when iterating.
        iteratorTypeName - The name of the iterator type (for logging close problems).
        executorName - The name for the executor.
        logService - The log service to retrieve the logger for log messages from.

    • Method Detail

      • shutdown

        public void shutdown()
        Shuts the executor service down and waits for the termination of running threads.

      • closeOrDefer

        protected void closeOrDefer​(boolean close,
                            UUID iteratorId,
                            T iterator)
        Closes the designated iterator immediately or registers for close notification so that the iterator will be removed from iterators.
        Parameters:
        close - Whether to close the designated iterator immediately.
        iteratorId - The ID of the designated iterator for logging purpose.
        iterator - The iterator which to close or which to remove later.

      • closeOrDefer

        @Deprecated(since="15.0.0",
            forRemoval=true)
protected void closeOrDefer​(boolean close,
                            UUID iteratorId,
                            T iterator,
                            de.aristaflow.adept2.model.communication.ServerSideProxy.LegacySspCloser legacyCloser)
        Deprecated, for removal: This API element is subject to removal in a future version.
        Use closeOrDefer(boolean, UUID, ServerSideProxy) instead unless having a proxy object of which the server-side object does not have ServerSideProxy.close() yet.
        Closes the designated iterator immediately or registers for close notification so that the iterator will be removed from iterators. In case of an UndeclaredThrowableException or a NoSuchMethodError, the designated LegacySspCloser will be called allowing to call the old method for closing instead of ServerSideProxy.close(). This is required for proxies stemming from servers before 15.0.0 where the server-side object does not implement ServerSideProxy.close().
        Parameters:
        close - Whether to close the designated iterator immediately.
        iteratorId - The ID of the designated iterator for logging purpose.
        iterator - The iterator which to close or which to remove later.
        legacyCloser - The methods for closing the ServerSideProxy with legacy methods instead of ServerSideProxy.close() or null to only use the standard ServerSideProxy.close().

      • getIterator

        protected T getIterator​(UUID iteratorId)
        Gets the iterator (with metadata) with the designated ID.
        Parameters:
        iteratorId - The ID of the iterator with metadata to retrieve.
        Returns:
        The iterator (with metadata) with the designated ID.
        Throws:
        IllegalArgumentException - If the designated ID does not refer to an iterator known by this handler, an IllegalArgumentException will be thrown.

      • close

        public void close​(@NotNull
                  @NotNull UUID iteratorId)
           throws IOException
        Calls ServerSideProxy.close() on the designated iterator and removes it from this handler.
        Parameters:
        iteratorId - The ID of the iterator to close.
        Throws:
        IllegalArgumentException - If the designated ID does not refer to a ServerSideProxy known by this handler, an IllegalArgumentException will be thrown.
        IOException - If there are problems accessing the underlying data source, an IOException will be thrown.
        de.aristaflow.adept2.model.communication.ServiceConnectionException - If the designated server-side proxy has been closed implicitly, a ServiceConnectionException will be thrown on client side.