Spliterators.AbstractLongSpliterator

public static abstract class Spliterators.AbstractLongSpliterator
extends Object implements Spliterator.OfLong

java.lang.Object
   ↳ java.util.Spliterators.AbstractLongSpliterator


An abstract Spliterator.OfLong that implements trySplit to permit limited parallelism.

To implement a spliterator an extending class need only implement tryAdvance. The extending class should override forEachRemaining if it can provide a more performant implementation.

Summary

Inherited constants

int CONCURRENT

Characteristic value signifying that the element source may be safely concurrently modified (allowing additions, replacements, and/or removals) by multiple threads without external synchronization.

int DISTINCT

Characteristic value signifying that, for each pair of encountered elements x, y, !x.equals(y).

int IMMUTABLE

Characteristic value signifying that the element source cannot be structurally modified; that is, elements cannot be added, replaced, or removed, so such changes cannot occur during traversal.

int NONNULL

Characteristic value signifying that the source guarantees that encountered elements will not be null.

int ORDERED

Characteristic value signifying that an encounter order is defined for elements.

int SIZED

Characteristic value signifying that the value returned from estimateSize() prior to traversal or splitting represents a finite size that, in the absence of structural source modification, represents an exact count of the number of elements that would be encountered by a complete traversal.

int SORTED

Characteristic value signifying that encounter order follows a defined sort order.

int SUBSIZED

Characteristic value signifying that all Spliterators resulting from trySplit() will be both SIZED and SUBSIZED.

Protected constructors

AbstractLongSpliterator(long est, int additionalCharacteristics)

Creates a spliterator reporting the given estimated size and characteristics.

Public methods

int characteristics()

Returns a set of characteristics of this Spliterator and its elements.

long estimateSize()

Returns an estimate of the number of elements that would be encountered by a forEachRemaining(Consumer) traversal, or returns Long.MAX_VALUE if infinite, unknown, or too expensive to compute.

Spliterator.OfLong trySplit()

If this spliterator can be partitioned, returns a Spliterator covering elements, that will, upon return from this method, not be covered by this Spliterator. This implementation permits limited parallelism.

Inherited methods

Object clone()

Creates and returns a copy of this object.

boolean equals(Object obj)

Indicates whether some other object is "equal to" this one.

void finalize()

Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.

final Class<?> getClass()

Returns the runtime class of this Object.

int hashCode()

Returns a hash code value for the object.

final void notify()

Wakes up a single thread that is waiting on this object's monitor.

final void notifyAll()

Wakes up all threads that are waiting on this object's monitor.

String toString()

Returns a string representation of the object.

final void wait(long timeoutMillis, int nanos)

Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

final void wait(long timeoutMillis)

Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

final void wait()

Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

default void forEachRemaining(LongConsumer action)
default void forEachRemaining(Consumer<? super Long> action)

abstract boolean tryAdvance(LongConsumer action)
default boolean tryAdvance(Consumer<? super Long> action)

abstract Spliterator.OfLong trySplit()

If this spliterator can be partitioned, returns a Spliterator covering elements, that will, upon return from this method, not be covered by this Spliterator.

default void forEachRemaining(LongConsumer action)

Performs the given action for each remaining element, sequentially in the current thread, until all elements have been processed or the action throws an exception.

abstract boolean tryAdvance(LongConsumer action)

If a remaining element exists, performs the given action on it, returning true; else returns false.

abstract T_SPLITR trySplit()

If this spliterator can be partitioned, returns a Spliterator covering elements, that will, upon return from this method, not be covered by this Spliterator.

abstract int characteristics()

Returns a set of characteristics of this Spliterator and its elements.

abstract long estimateSize()

Returns an estimate of the number of elements that would be encountered by a forEachRemaining(Consumer) traversal, or returns Long.MAX_VALUE if infinite, unknown, or too expensive to compute.

default void forEachRemaining(Consumer<? super T> action)

Performs the given action for each remaining element, sequentially in the current thread, until all elements have been processed or the action throws an exception.

default Comparator<? super T> getComparator()

If this Spliterator's source is SORTED by a Comparator, returns that Comparator.

default long getExactSizeIfKnown()

Convenience method that returns estimateSize() if this Spliterator is SIZED, else -1.

default boolean hasCharacteristics(int characteristics)

Returns true if this Spliterator's characteristics() contain all of the given characteristics.

abstract boolean tryAdvance(Consumer<? super T> action)

If a remaining element exists: performs the given action on it, returning true; else returns false.

abstract Spliterator<Long> trySplit()

If this spliterator can be partitioned, returns a Spliterator covering elements, that will, upon return from this method, not be covered by this Spliterator.

Protected constructors

AbstractLongSpliterator

Added in API level 24
protected AbstractLongSpliterator (long est, 
                int additionalCharacteristics)

Creates a spliterator reporting the given estimated size and characteristics.

Parameters
est long: the estimated size of this spliterator if known, otherwise Long.MAX_VALUE.

additionalCharacteristics int: properties of this spliterator's source or elements. If SIZED is reported then this spliterator will additionally report SUBSIZED.

Public methods

characteristics

Added in API level 24
public int characteristics ()

Returns a set of characteristics of this Spliterator and its elements. The result is represented as ORed values from ORDERED, DISTINCT, SORTED, SIZED, NONNULL, IMMUTABLE, CONCURRENT, SUBSIZED. Repeated calls to characteristics() on a given spliterator, prior to or in-between calls to trySplit, should always return the same result.

If a Spliterator reports an inconsistent set of characteristics (either those returned from a single invocation or across multiple invocations), no guarantees can be made about any computation using this Spliterator.

Implementation Requirements:
  • This implementation returns the characteristics as reported when created.
Returns
int a representation of characteristics

estimateSize

Added in API level 24
public long estimateSize ()

Returns an estimate of the number of elements that would be encountered by a forEachRemaining(Consumer) traversal, or returns Long.MAX_VALUE if infinite, unknown, or too expensive to compute.

If this Spliterator is SIZED and has not yet been partially traversed or split, or this Spliterator is SUBSIZED and has not yet been partially traversed, this estimate must be an accurate count of elements that would be encountered by a complete traversal. Otherwise, this estimate may be arbitrarily inaccurate, but must decrease as specified across invocations of trySplit().

Implementation Requirements:
  • This implementation returns the estimated size as reported when created and, if the estimate size is known, decreases in size when split.
Returns
long the estimated size, or Long.MAX_VALUE if infinite, unknown, or too expensive to compute.

trySplit

Added in API level 24
public Spliterator.OfLong trySplit ()

If this spliterator can be partitioned, returns a Spliterator covering elements, that will, upon return from this method, not be covered by this Spliterator.

If this Spliterator is ORDERED, the returned Spliterator must cover a strict prefix of the elements.

Unless this Spliterator covers an infinite number of elements, repeated calls to trySplit() must eventually return null. Upon non-null return:

  • the value reported for estimateSize() before splitting, must, after splitting, be greater than or equal to estimateSize() for this and the returned Spliterator; and
  • if this Spliterator is SUBSIZED, then estimateSize() for this spliterator before splitting must be equal to the sum of estimateSize() for this and the returned Spliterator after splitting.

This method may return null for any reason, including emptiness, inability to split after traversal has commenced, data structure constraints, and efficiency considerations. This implementation permits limited parallelism.

Returns
Spliterator.OfLong a Spliterator covering some portion of the elements, or null if this spliterator cannot be split