org.apache.dubbo.rpc.cluster.router.state

Interface StateRouter<T>

All Known Implementing Classes:

AbstractStateRouter, AppStateRouter, ConditionStateRouter, ListenableStateRouter, MeshRuleRouter, MockInvokersSelector, ScriptStateRouter, ServiceStateRouter, StandardMeshRuleRouter, TagStateRouter, TailStateRouter

public interface StateRouter<T>

State Router. (SPI, Prototype, ThreadSafe)

Routing It is recommended to implement StateRouter by extending AbstractStateRouter

Since:

3.0

See Also:

Cluster.join(Directory, boolean), AbstractStateRouter, Directory.list(Invocation)

Method Summary

Modifier and Type	Method and Description
String	buildSnapshot() Build Router's Current State Snapshot for QoS
org.apache.dubbo.common.URL	getUrl() Get the router url.
boolean	isForce() To decide whether this router should take effect when none of the invoker can match the router rule, which means the route(BitList, URL, Invocation, boolean, Holder) would be empty.
boolean	isRuntime() To decide whether this router need to execute every time an RPC comes or should only execute when addresses or rule change.
void	notify(BitList<Invoker<T>> invokers) Notify the router the invoker list.
BitList<Invoker<T>>	route(BitList<Invoker<T>> invokers, org.apache.dubbo.common.URL url, Invocation invocation, boolean needToPrintMessage, org.apache.dubbo.common.utils.Holder<RouterSnapshotNode<T>> nodeHolder) Filter invokers with current routing rule and only return the invokers that comply with the rule.
void	setNextRouter(StateRouter<T> nextRouter) Notify next router node to current router.
default void	stop()

Method Detail

getUrl

org.apache.dubbo.common.URL getUrl()

Get the router url.

Returns:

url

route

BitList<Invoker<T>> route(BitList<Invoker<T>> invokers,
                          org.apache.dubbo.common.URL url,
                          Invocation invocation,
                          boolean needToPrintMessage,
                          org.apache.dubbo.common.utils.Holder<RouterSnapshotNode<T>> nodeHolder)
                   throws RpcException

Filter invokers with current routing rule and only return the invokers that comply with the rule. Caching address lists in BitMap mode improves routing performance.

Parameters:

invokers - invoker bit list

url - refer url

invocation - invocation

needToPrintMessage - whether to print router state. Such as `use router branch a`.

Returns:

state with route result

Throws:

RpcException

Since:

3.0

isRuntime

boolean isRuntime()

To decide whether this router need to execute every time an RPC comes or should only execute when addresses or rule change.

Returns:

true if the router need to execute every time.

isForce

boolean isForce()

To decide whether this router should take effect when none of the invoker can match the router rule, which means the route(BitList, URL, Invocation, boolean, Holder) would be empty. Most of time, most router implementation would default this value to false.

Returns:

true to execute if none of invokers matches the current router

notify

void notify(BitList<Invoker<T>> invokers)

Notify the router the invoker list. Invoker list may change from time to time. This method gives the router a chance to prepare before route(BitList, URL, Invocation, boolean, Holder) gets called. No need to notify next node.

Parameters:

invokers - invoker list

buildSnapshot

String buildSnapshot()

Build Router's Current State Snapshot for QoS

Returns:

Current State

stop

default void stop()

setNextRouter

void setNextRouter(StateRouter<T> nextRouter)

Notify next router node to current router.

Parameters:

nextRouter - next router node