com.hazelcast.map.impl.querycache.accumulator

Interface CyclicBuffer<E extends Sequenced>

Type Parameters:

E - the type of elements in this buffer.

All Known Implementing Classes:

DefaultCyclicBuffer

public interface CyclicBuffer<E extends Sequenced>

A cyclic buffer to store Sequenced events. Only additions can be done to this buffer. If capacity is not sufficient subsequent additions will be done by overwriting existing ones. Also read access to any element is possible by providing the sequence number.

Method Summary

Modifier and Type	Method and Description
void	add(E event) Adds an event to this buffer and sets tail to the sequence of given event.
E	get(long sequence) Returns the element in this buffer which has the supplied sequence.
E	getAndAdvance() Returns next unread event from this buffer and advances head sequence of this buffer by one.
long	getHeadSequence() Returns the sequence number of the element in the head index of this buffer if there exists any, otherwise -1L will be returned.
void	reset() Resets this buffer; after the return of this method buffer will be empty and all elements in it will be null.
boolean	setHead(long sequence) Sets head of this buffer to the supplied sequence and returns true, if that sequence is still in this buffer.
int	size() Returns the size of unread events in this buffer according to the current head.

Method Detail

add

void add(E event)

Adds an event to this buffer and sets tail to the sequence of given event.

Parameters:

event - the event to be added.

getAndAdvance

E getAndAdvance()

Returns next unread event from this buffer and advances head sequence of this buffer by one.

Returns:

next unread event.

get

E get(long sequence)

Returns the element in this buffer which has the supplied sequence.

Parameters:

sequence - the sequence number of the event.

Returns:

the element with the supplied sequence.

setHead

boolean setHead(long sequence)

Sets head of this buffer to the supplied sequence and returns true, if that sequence is still in this buffer. Otherwise, returns false

Parameters:

sequence - the sequence number which will be set to head of this buffer.

Returns:

true if sequence is set to head, otherwise returns false.

getHeadSequence

long getHeadSequence()

Returns the sequence number of the element in the head index of this buffer if there exists any, otherwise -1L will be returned.

Returns:

the sequence number of the element in the head index or -1L.

reset

void reset()

Resets this buffer; after the return of this method buffer will be empty and all elements in it will be null.

size

int size()

Returns the size of unread events in this buffer according to the current head.

Returns:

the size of unread events in this buffer.