reactor.core

Enum Scannable.Attr

java.lang.Object

java.lang.Enum<Scannable.Attr>

reactor.core.Scannable.Attr

All Implemented Interfaces:

Serializable, Comparable<Scannable.Attr>

Enclosing interface:

Scannable

public static enum Scannable.Attr
extends Enum<Scannable.Attr>

A list of reserved keys for component state scanning

Enum Constant Summary

Enum Constants

Enum Constant and Description
ACTUAL The direct dependent component downstream reference if any.
BUFFERED A Integer attribute implemented by components with a backlog capacity.
CANCELLED A Boolean attribute indicating whether or not a downstream component has interrupted consuming this scanned component, e.g., a cancelled subscription.
CAPACITY Return an an Integer capacity when no PREFETCH is defined or when an arbitrary maximum limit is applied to the backlog capacity of the scanned component.
DELAY_ERROR Delay_Error exposes a Boolean whether the scanned component actively supports error delaying if it manages a backlog instead of fast error-passing which might drop pending backlog.
ERROR a Throwable attribute which indicate an error state if the scanned component keeps track of it.
PARENT Parent key exposes the direct upstream relationship of the scanned component.
PREFETCH Prefetch is an Integer attribute defining the rate of processing in a component which has capacity to request and hold a backlog of data.
REQUESTED_FROM_DOWNSTREAM A Long attribute exposing the current pending demand of a downstream component.
TERMINATED A Boolean attribute indicating whether or not an upstream component terminated this scanned component.

Method Summary

Modifier and Type	Method and Description
static Scannable.Attr	valueOf(String name) Returns the enum constant of this type with the specified name.
static Scannable.Attr[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

PARENT

public static final Scannable.Attr PARENT

Parent key exposes the direct upstream relationship of the scanned component. It can be a Publisher source to an operator, a Subscription to a Subscriber (main flow if ambiguous with inner Subscriptions like flatMap), a Scheduler to a Worker.

Scannable.parents() can be used to navigate the parent chain.

DELAY_ERROR

public static final Scannable.Attr DELAY_ERROR

Delay_Error exposes a Boolean whether the scanned component actively supports error delaying if it manages a backlog instead of fast error-passing which might drop pending backlog.

Note: This attribute usually resolves to a constant value

PREFETCH

public static final Scannable.Attr PREFETCH

Prefetch is an Integer attribute defining the rate of processing in a component which has capacity to request and hold a backlog of data. It usually maps to a component capacity when no arbitrary CAPACITY is set. Integer.MAX_VALUE signal unlimited capacity and therefore unbounded demand.

Note: This attribute usually resolves to a constant value

CAPACITY

public static final Scannable.Attr CAPACITY

Return an an Integer capacity when no PREFETCH is defined or when an arbitrary maximum limit is applied to the backlog capacity of the scanned component. Integer.MAX_VALUE signal unlimited capacity.

Note: This attribute usually resolves to a constant value

ACTUAL

public static final Scannable.Attr ACTUAL

The direct dependent component downstream reference if any. Operators in Flux/Mono for instance delegate to a target Subscriber, which is going to be the actual chain navigated with this reference key.

A reference chain downstream can be navigated via Scannable.actuals().

ERROR

public static final Scannable.Attr ERROR

a Throwable attribute which indicate an error state if the scanned component keeps track of it.

BUFFERED

public static final Scannable.Attr BUFFERED

A Integer attribute implemented by components with a backlog capacity. It will expose current queue size or similar related to user-provided held data.

REQUESTED_FROM_DOWNSTREAM

public static final Scannable.Attr REQUESTED_FROM_DOWNSTREAM

A Long attribute exposing the current pending demand of a downstream component. Note that Long.MAX_VALUE indicates an unbounded (push-style) demand as specified in Subscription.request(long).

CANCELLED

public static final Scannable.Attr CANCELLED

A Boolean attribute indicating whether or not a downstream component has interrupted consuming this scanned component, e.g., a cancelled subscription. Note that it differs from TERMINATED which is intended for "normal" shutdown cycles.

TERMINATED

public static final Scannable.Attr TERMINATED

A Boolean attribute indicating whether or not an upstream component terminated this scanned component. e.g. a post onComplete/onError subscriber. By opposition to CANCELLED which determines if a downstream component interrupted this scanned component.

Method Detail

values

public static Scannable.Attr[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (Scannable.Attr c : Scannable.Attr.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static Scannable.Attr valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null