E- The type of event this history contains.
@ThreadSafe public interface UserHistory<E extends Event> extends List<E>
|Modifier and Type||Method and Description|
Filter the user history to only contain elements of a particular type.
Filter the user history with a predicate.
Retrieve the user ID.
Get the set of items touched by events in this history.
Apply a function to this history, memoizing its return value.
add, add, addAll, addAll, clear, contains, containsAll, equals, get, hashCode, indexOf, isEmpty, iterator, lastIndexOf, listIterator, listIterator, remove, remove, removeAll, replaceAll, retainAll, set, size, sort, spliterator, subList, toArray, toArray
<T extends Event> UserHistory<T> filter(Class<T> type)
T- The type of element to include.
type- The type of elements to include.
UserHistory<E> filter(Predicate<? super E> pred)
pred- The predicate to with which to filter the history.
<T> T memoize(Function<? super UserHistory<E>,? extends T> func)
Object.hashCode()methods in order for memoization to work well.
This method is not guaranteed to be synchronized. It is safe to memoize
distinct functions in parallel, but potentially-parallel use of the same
function must be synchronized by client code or the function may be called
twice. The implementation in
AbstractUserHistory uses a
ConcurrentHashMap. Multiple calls are therefore safe, but may
result in extra work. All implementations must maintain this safety
guarantee, although they may do so by synchronizing this method.
T- The return type of the function.
func- The function to call and memoize.