org.apache.flink.runtime.state

Interface InternalPriorityQueue<T>

Type Parameters:

T - type of elements in the ordered set.

All Known Subinterfaces:

KeyGroupedInternalPriorityQueue<T>

All Known Implementing Classes:

AbstractHeapPriorityQueue, HeapPriorityQueue, HeapPriorityQueueSet, KeyGroupPartitionedPriorityQueue, RocksDBCachingPriorityQueueSet

@Internal
public interface InternalPriorityQueue<T>

Interface for collection that gives in order access to elements w.r.t their priority.

Method Summary

Modifier and Type	Method and Description
boolean	add(T toAdd) Adds the given element to the set, if it is not already contained.
void	addAll(Collection<? extends T> toAdd) Adds all the given elements to the set.
boolean	isEmpty() Check if the set contains any elements.
CloseableIterator<T>	iterator() Iterator over all elements, no order guaranteed.
T	peek() Retrieves, but does not remove, the element (w.r.t.
T	poll() Retrieves and removes the first element (w.r.t.
boolean	remove(T toRemove) Removes the given element from the set, if is contained in the set.
int	size() Returns the number of elements in this set.

Method Detail

poll

@Nullable
T poll()

Retrieves and removes the first element (w.r.t. the order) of this set, or returns null if this set is empty.

Returns:

the first element of this ordered set, or null if this set is empty.

peek

@Nullable
T peek()

Retrieves, but does not remove, the element (w.r.t. order) of this set, or returns null if this set is empty.

Returns:

the first element (w.r.t. order) of this ordered set, or null if this set is empty.

add

boolean add(@Nonnull
            T toAdd)

Adds the given element to the set, if it is not already contained.

Parameters:

toAdd - the element to add to the set.

Returns:

true if the operation changed the head element or if it is unclear if the head element changed. Only returns false if the head element was not changed by this operation.

remove

boolean remove(@Nonnull
               T toRemove)

Removes the given element from the set, if is contained in the set.

Parameters:

toRemove - the element to remove.

Returns:

true if the operation changed the head element or if it is unclear if the head element changed. Only returns false if the head element was not changed by this operation.

isEmpty

boolean isEmpty()

Check if the set contains any elements.

Returns:

true if the set is empty, i.e. no element is contained.

size

@Nonnegative
int size()

Returns the number of elements in this set.

Returns:

the number of elements in this set.

addAll

void addAll(@Nullable
            Collection<? extends T> toAdd)

Adds all the given elements to the set.

iterator

@Nonnull
CloseableIterator<T> iterator()

Iterator over all elements, no order guaranteed. Iterator must be closed after usage.