Package org.apache.flink.queryablestate.network

Class AbstractServerHandler<REQ extends MessageBody,RESP extends MessageBody>

java.lang.Object

org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerAdapter

org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandlerAdapter

org.apache.flink.queryablestate.network.AbstractServerHandler<REQ,RESP>

Type Parameters:

REQ - the type of request the server expects to receive.

RESP - the type of response the server will send.

All Implemented Interfaces:

org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandler, org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandler

@Internal
@Sharable
public abstract class AbstractServerHandler<REQ extends MessageBody,RESP extends MessageBody>
extends org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandlerAdapter

The base class of every handler used by an AbstractServerBase.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandler

org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandler.Sharable

Field Summary

Fields

Modifier and Type	Field	Description
protected final ExecutorService	queryExecutor	Thread pool for query execution.

Constructor Summary

Constructors

Constructor	Description
AbstractServerHandler(AbstractServerBase<REQ,RESP> server, MessageSerializer<REQ,RESP> serializer, KvStateRequestStats stats)	Create the handler.

Method Summary

Modifier and Type	Method	Description
void	channelActive(org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext ctx)
void	channelInactive(org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext ctx)
void	channelRead(org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext ctx, Object msg)
void	exceptionCaught(org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext ctx, Throwable cause)
protected String	getServerName()
abstract CompletableFuture<RESP>	handleRequest(long requestId, REQ request)	Handles an incoming request and returns a CompletableFuture containing the corresponding response.
abstract CompletableFuture<Void>	shutdown()	Shuts down any handler-specific resources, e.g. thread pools etc and returns a CompletableFuture.

Methods inherited from class org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandlerAdapter

channelReadComplete, channelRegistered, channelUnregistered, channelWritabilityChanged, userEventTriggered

Methods inherited from class org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, handlerAdded, handlerRemoved, isSharable

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandler

handlerAdded, handlerRemoved

Field Details

queryExecutor

protected final ExecutorService queryExecutor

Thread pool for query execution.

Constructor Details

AbstractServerHandler

public AbstractServerHandler(AbstractServerBase<REQ,RESP> server,
 MessageSerializer<REQ,RESP> serializer,
 KvStateRequestStats stats)

Create the handler.

Parameters:

serializer - the serializer used to (de-)serialize messages

stats - statistics collector

Method Details

getServerName

protected String getServerName()

channelActive

public void channelActive(org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext ctx)
                   throws Exception

Specified by:

channelActive in interface org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandler

Overrides:

channelActive in class org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandlerAdapter

Throws:

Exception

channelInactive

public void channelInactive(org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext ctx)
                     throws Exception

Specified by:

channelInactive in interface org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandler

Overrides:

channelInactive in class org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandlerAdapter

Throws:

Exception

channelRead

public void channelRead(org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext ctx,
 Object msg)
                 throws Exception

Specified by:

channelRead in interface org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandler

Overrides:

channelRead in class org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandlerAdapter

Throws:

Exception

exceptionCaught

public void exceptionCaught(org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext ctx,
 Throwable cause)
                     throws Exception

Specified by:

exceptionCaught in interface org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandler

Specified by:

exceptionCaught in interface org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandler

Overrides:

exceptionCaught in class org.apache.flink.shaded.netty4.io.netty.channel.ChannelInboundHandlerAdapter

Throws:

Exception

handleRequest

public abstract CompletableFuture<RESP> handleRequest(long requestId,
 REQ request)

Handles an incoming request and returns a CompletableFuture containing the corresponding response.

NOTE: This method is called by multiple threads.

Parameters:

requestId - the id of the received request to be handled.

request - the request to be handled.

Returns:

A future with the response to be forwarded to the client.

shutdown

public abstract CompletableFuture<Void> shutdown()

Shuts down any handler-specific resources, e.g. thread pools etc and returns a CompletableFuture.

If an exception is thrown during the shutdown process, then that exception will be included in the returned future.

Returns:

A CompletableFuture that will be completed when the shutdown process actually finishes.