com.hazelcast.map.impl.querycache.accumulator

Interface Accumulator<E extends Sequenced>

Type Parameters:

E - the allowed type for this accumulator to accumulate.

All Superinterfaces:

Iterable<E>

All Known Implementing Classes:

BasicAccumulator, SubscriberAccumulator

public interface Accumulator<E extends Sequenced>
extends Iterable<E>

Accumulator for events which have a sequence number. Only allows read access to elements in it, except reset() method.

See Also:

Sequenced

Method Summary

Modifier and Type	Method and Description
void	accumulate(E event) Adds event to this accumulator.
AccumulatorInfo	getInfo() Returns AccumulatorInfo of this accumulator.
boolean	isEmpty() Returns true if this accumulator contains no elements.
Iterator<E>	iterator() Returns an iterator over the items in this accumulator in proper sequence.
int	poll(AccumulatorHandler<E> handler, int maxItems) Reads this accumulator if it contains at least maxItems, otherwise do not read anything.
int	poll(AccumulatorHandler<E> handler, long delay, TimeUnit unit) Reads all expired items to the supplied handler.
void	reset() Resets this accumulator.
boolean	setHead(long sequence) Tries to set head of this accumulator to the supplied sequence and returns true, if that sequence is still exist in this accumulator.
int	size() Current size of accumulator.

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Method Detail

accumulate

void accumulate(E event)

Adds event to this accumulator.

Parameters:

event - event to add.

poll

int poll(AccumulatorHandler<E> handler,
         int maxItems)

Reads this accumulator if it contains at least maxItems, otherwise do not read anything. If this method adds items to the supplied handler, head of this accumulator advances. Used for batching purposes.

Parameters:

handler - handler to process this accumulator.

maxItems - read this accumulator if it contains at least maxItems

Returns:

the number of elements read.

poll

int poll(AccumulatorHandler<E> handler,
         long delay,
         TimeUnit unit)

Reads all expired items to the supplied handler. If this method adds items to the supplied handler, head of this accumulator advances.

Parameters:

handler - handler to process this accumulator.

delay - after this duration element will be poll-able.

unit - time-unit

Returns:

the number of elements polled.

iterator

Iterator<E> iterator()

Returns an iterator over the items in this accumulator in proper sequence. Also this methods advances head of this accumulator.

Specified by:

iterator in interface Iterable<E extends Sequenced>

Returns:

an iterator over the items in this list accumulator in proper sequence.

getInfo

AccumulatorInfo getInfo()

Returns AccumulatorInfo of this accumulator.

Returns:

AccumulatorInfo of this accumulator.

setHead

boolean setHead(long sequence)

Tries to set head of this accumulator to the supplied sequence and returns true, if that sequence is still exist in this accumulator. Otherwise, returns false.

Parameters:

sequence - the sequence number which will be the head of this accumulator.

Returns:

true if sequence is set, otherwise returns false

size

int size()

Current size of accumulator.

Returns:

returns current size of accumulator.

isEmpty

boolean isEmpty()

Returns true if this accumulator contains no elements.

Returns:

true if this accumulator contains no elements

reset

void reset()

Resets this accumulator. After return of this call, accumulator will be in its initial state.