Package com.apple.foundationdb.async

Interface AsyncPeekCallbackIterator<T>

Type Parameters:
T - type of elements returned by the scan
All Superinterfaces:
AsyncIterator<T>, AsyncPeekIterator<T>, Iterator<T>
public interface AsyncPeekCallbackIterator<T> extends AsyncPeekIterator<T>
An AsyncPeekCallbackIterator is an extension of the AsyncPeekIterator interface that can be given a callback to call after each time it advances. Note that the AsyncPeekCallbackIterator is mostly a tag interface and does not contain any logic for executing the callback after yielding each result; conforming implementations must implement that logic.

  • Method Details

    • wrap

      static <T> AsyncPeekCallbackIterator<T> wrap(@Nonnull AsyncIterator<T> iterator, @Nonnull Consumer<T> callback)
      Wrap an AsyncIterator with an AsyncPeekCallbackIterator. The returned iterator returns the same sequence of elements as the supplied AsyncIterator instance in the same order. The wrapping implementation is free to advance the underlying iterator, so it is unsafe to modify iterator directly after calling this method. The returned iterator is also not thread safe, so concurrent calls to onHasNext, for example, may lead to unexpected behavior.
      Type Parameters:
      T - type of items returned by the scan
      Parameters:
      iterator - AsyncIterator to wrap
      callback - a callback to call when AsyncIterator.next() produces a result
      Returns:
      an iterator over the same values as iterator that supports peek and callback semantics

    • setCallback

      void setCallback(@Nonnull Consumer<T> callback)
      Set the callback to the provided Consumer.
      Parameters:
      callback - a consumer to call when a new result is produced by AsyncIterator.next()

    • getCallback

      @Nonnull Consumer<T> getCallback()
      Return the callback that this iterator calls before a new result is returned by AsyncIterator.next().
      Returns:
      the callback that this iterator calls before a new result is returned by AsyncIterator.next();W