Module io.helidon.common.reactive

Package io.helidon.common.reactive

Class RequestedCounter

java.lang.Object

io.helidon.common.reactive.RequestedCounter

public class RequestedCounter
extends Object

Requested event counter. This utility class helps to safely track and process the back-pressure of Flow.Subscribers.

Constructor Summary

Constructors

Constructor	Description
RequestedCounter()	Create new request counter with strict mode off.
RequestedCounter(boolean strictMode)	Create new request counter, with strict mode true are all operations with counter protected by lock.

Method Summary

Modifier and Type	Method	Description
long	get()	Gets the current requested event counter value.
void	increment(long increment, Consumer<? super IllegalArgumentException> errorHandler)	Increments safely a requested event counter to prevent Long.MAX_VALUE overflow.
void	lock()	Lock internal counter if strict mode is on.
boolean	tryDecrement()	Tries to safely decrement a positive requested counter value, making sure the value does not drop below zero.
void	unlock()	Unlock internal counter.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

RequestedCounter

public RequestedCounter()

Create new request counter with strict mode off.

RequestedCounter

public RequestedCounter(boolean strictMode)

Create new request counter, with strict mode true are all operations with counter protected by lock.

Parameters:

strictMode - true for turning strict mode on

Method Details

increment

public void increment(long increment,
 Consumer<? super IllegalArgumentException> errorHandler)

Increments safely a requested event counter to prevent Long.MAX_VALUE overflow.

Parameters:

increment - amount of additional events to request.

errorHandler - a consumer of IllegalArgumentException to process errors

tryDecrement

public boolean tryDecrement()

Tries to safely decrement a positive requested counter value, making sure the value does not drop below zero.

Returns:

true if the initial positive value has been decremented successfully, false in case the initial counter value was already set to zero.

lock

public void lock()

Lock internal counter if strict mode is on.

unlock

public void unlock()

Unlock internal counter.

get

public long get()

Gets the current requested event counter value.

Returns:

current value of the requested event counter.