io.smallrye.reactive.messaging.annotations.OnOverflow Maven / Gradle / Ivy
package io.smallrye.reactive.messaging.annotations;
import static java.lang.annotation.ElementType.CONSTRUCTOR;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.PARAMETER;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Allows configuring the back pressure policy on injected {@link Emitter}:
*
*
* {
* @code
* @Channel("channel")
* @OnOverflow(value = OnOverflow.Strategy.BUFFER, bufferSize = 256)
* Emitter emitter;
* }
*
*
*
* When not used, a {@link OnOverflow.Strategy#BUFFER} strategy is used with a buffer limited to 128 elements.
*
* @deprecated Use {@link org.eclipse.microprofile.reactive.messaging.OnOverflow} instead
*/
@Retention(RetentionPolicy.RUNTIME)
@Target({ METHOD, CONSTRUCTOR, FIELD, PARAMETER })
@Deprecated
public @interface OnOverflow {
/**
* The back pressure strategy.
*/
enum Strategy {
/**
* Buffers all values until the downstream consumes it.
* This creates a buffer with the size specified by {@link #bufferSize()} if present.
* Otherwise, the size will be the value of the config property
* mp.messaging.emitter.default-buffer-size.
* If the buffer is full, an error will be propagated.
*/
BUFFER,
/**
* Buffers all values until the downstream consumes it.
* This creates an unbounded buffer. If the buffer is full, the application will die of {@code OutOfMemory}.
*/
UNBOUNDED_BUFFER,
/**
* Drops the most recent value if the downstream can't keep up. It means that new values emitted by the upstream
* are ignored.
*/
DROP,
/**
* Propagates a failure in case the downstream can't keep up.
*/
FAIL,
/**
* Keeps only the latest value, dropping any previous values if the downstream can't keep up.
*/
LATEST,
/**
* The values are propagated without any back pressure strategy. It's the responsibility from the downstream to
* implement a strategy to deal with overflow.
*/
NONE
}
/**
* @return the name of the strategy to be used on overflow.
*/
Strategy value();
/**
* @return the size of the buffer when {@link Strategy#BUFFER} is used. If not set and if the {@link Strategy#BUFFER}
* strategy is used, the buffer size will be defaulted to the value of the config property
* mp.messaging.emitter.default-buffer-size. If set the value must be strictly positive.
*/
long bufferSize() default 0;
}