com.couchbase.client.core.endpoint

Class AbstractGenericHandler<RESPONSE,ENCODED,REQUEST extends CouchbaseRequest>

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.channel.ChannelDuplexHandler

io.netty.handler.codec.MessageToMessageCodec<RESPONSE,REQUEST>

com.couchbase.client.core.endpoint.AbstractGenericHandler<RESPONSE,ENCODED,REQUEST>

All Implemented Interfaces:

ChannelHandler, ChannelInboundHandler, ChannelOutboundHandler

Direct Known Subclasses:

ConfigHandler, DCPHandler, KeyValueHandler, QueryHandler, SearchHandler, ViewHandler

public abstract class AbstractGenericHandler<RESPONSE,ENCODED,REQUEST extends CouchbaseRequest>
extends MessageToMessageCodec<RESPONSE,REQUEST>

Generic handler which acts as the common base type for all implementing handlers.

Since:

1.0

Author:

Michael Nitschinger

Nested Class Summary

Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler

ChannelHandler.Sharable

Field Summary

Fields

Modifier and Type	Field and Description
protected static Charset	CHARSET The default charset to use for all requests and responses.
protected static byte[]	EMPTY_BYTES Empty bytes to reuse.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractGenericHandler(AbstractEndpoint endpoint, com.lmax.disruptor.EventSink<ResponseEvent> responseBuffer, boolean isTransient) Creates a new AbstractGenericHandler with the default queue.
protected	AbstractGenericHandler(AbstractEndpoint endpoint, com.lmax.disruptor.EventSink<ResponseEvent> responseBuffer, Queue<REQUEST> queue, boolean isTransient) Creates a new AbstractGenericHandler with a custom queue.

Method Summary

Modifier and Type	Method and Description
static void	addHttpBasicAuth(ChannelHandlerContext ctx, HttpRequest request, String user, String password) Add basic authentication headers to a HttpRequest.
void	channelActive(ChannelHandlerContext ctx)
void	channelInactive(ChannelHandlerContext ctx)
void	channelWritabilityChanged(ChannelHandlerContext ctx)
void	connect(ChannelHandlerContext ctx, SocketAddress remoteAddress, SocketAddress localAddress, ChannelPromise future)
protected CouchbaseRequest	createKeepAliveRequest() Override to return a non-null request to be fired in the pipeline in case a keep alive is triggered.
protected REQUEST	currentRequest() Returns the current request if set.
protected void	currentRequest(REQUEST request) Sets current request.
protected void	decode(ChannelHandlerContext ctx, RESPONSE msg, List<Object> out)
protected abstract CouchbaseResponse	decodeResponse(ChannelHandlerContext ctx, RESPONSE msg) Decodes the incoming response and transforms it into a CouchbaseResponse.
protected void	encode(ChannelHandlerContext ctx, REQUEST msg, List<Object> out)
protected abstract ENCODED	encodeRequest(ChannelHandlerContext ctx, REQUEST msg) Encode the outgoing request and return it in encoded format.
protected AbstractEndpoint	endpoint() The parent endpoint.
protected CoreEnvironment	env() Returns environment.
void	exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
protected void	finishedDecoding() Notify that decoding is finished.
void	handlerRemoved(ChannelHandlerContext ctx)
protected static String	logIdent(ChannelHandlerContext ctx, Endpoint endpoint) Simple log helper to give logs a common prefix.
protected void	onKeepAliveFired(ChannelHandlerContext ctx, CouchbaseRequest keepAliveRequest) Override to customize the behavior when a keep alive has been triggered and a keep alive request sent.
protected void	onKeepAliveResponse(ChannelHandlerContext ctx, CouchbaseResponse keepAliveResponse) Override to customize the behavior when a keep alive has been responded to.
protected void	publishResponse(CouchbaseResponse response, Subject<CouchbaseResponse,CouchbaseResponse> observable) Publishes a response with the attached observable.
protected String	remoteHostname()
protected String	remoteHttpHost(ChannelHandlerContext ctx) Helper method to return the remote http host, cached.
protected abstract ServiceType	serviceType() Returns the ServiceType associated with this handler.
protected void	sideEffectRequestToCancel(REQUEST request) This method can be overridden as it is called every time an operation is cancelled.
void	userEventTriggered(ChannelHandlerContext ctx, Object evt)

Methods inherited from class io.netty.handler.codec.MessageToMessageCodec

acceptInboundMessage, acceptOutboundMessage, channelRead, write

Methods inherited from class io.netty.channel.ChannelDuplexHandler

bind, close, deregister, disconnect, flush, read

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter

channelReadComplete, channelRegistered, channelUnregistered

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

handlerAdded, isSharable

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.netty.channel.ChannelHandler

handlerAdded

Field Detail

CHARSET

protected static final Charset CHARSET

The default charset to use for all requests and responses.

EMPTY_BYTES

protected static final byte[] EMPTY_BYTES

Empty bytes to reuse.

Constructor Detail

AbstractGenericHandler

protected AbstractGenericHandler(AbstractEndpoint endpoint,
                                 com.lmax.disruptor.EventSink<ResponseEvent> responseBuffer,
                                 boolean isTransient)

Creates a new AbstractGenericHandler with the default queue.

Parameters:

endpoint - the endpoint reference.

responseBuffer - the response buffer.

AbstractGenericHandler

protected AbstractGenericHandler(AbstractEndpoint endpoint,
                                 com.lmax.disruptor.EventSink<ResponseEvent> responseBuffer,
                                 Queue<REQUEST> queue,
                                 boolean isTransient)

Creates a new AbstractGenericHandler with a custom queue.

Parameters:

endpoint - the endpoint reference.

responseBuffer - the response buffer.

queue - the queue.

Method Detail

encodeRequest

protected abstract ENCODED encodeRequest(ChannelHandlerContext ctx,
                                         REQUEST msg)
                                  throws Exception

Encode the outgoing request and return it in encoded format.

This method needs to be implemented by the child handler and is responsible for the actual conversion.

Parameters:

ctx - the context passed in.

msg - the outgoing message.

Returns:

the encoded request.

Throws:

Exception - as a generic error.

decodeResponse

protected abstract CouchbaseResponse decodeResponse(ChannelHandlerContext ctx,
                                                    RESPONSE msg)
                                             throws Exception

Decodes the incoming response and transforms it into a CouchbaseResponse.

Note that the actual notification is handled by this generic handler, the implementing class only is concerned about the conversion itself.

Parameters:

ctx - the context passed in.

msg - the incoming message.

Returns:

a response or null if nothing should be returned.

Throws:

Exception - as a generic error. It will be bubbled up to the user (wrapped in a CouchbaseException) in the onError of the request’s Observable.

serviceType

protected abstract ServiceType serviceType()

Returns the ServiceType associated with this handler.

Returns:

the service type.

encode

protected void encode(ChannelHandlerContext ctx,
                      REQUEST msg,
                      List<Object> out)
               throws Exception

Specified by:

encode in class MessageToMessageCodec<RESPONSE,REQUEST extends CouchbaseRequest>

Throws:

Exception

decode

protected void decode(ChannelHandlerContext ctx,
                      RESPONSE msg,
                      List<Object> out)
               throws Exception

Specified by:

decode in class MessageToMessageCodec<RESPONSE,REQUEST extends CouchbaseRequest>

Throws:

Exception

publishResponse

protected void publishResponse(CouchbaseResponse response,
                               Subject<CouchbaseResponse,CouchbaseResponse> observable)

Publishes a response with the attached observable.

Parameters:

response - the response to publish.

observable - pushing into the event sink.

finishedDecoding

protected void finishedDecoding()

Notify that decoding is finished. This needs to be called by the child handlers in order to signal that operations are done.

channelInactive

public void channelInactive(ChannelHandlerContext ctx)
                     throws Exception

Specified by:

channelInactive in interface ChannelInboundHandler

Overrides:

channelInactive in class ChannelInboundHandlerAdapter

Throws:

Exception

channelActive

public void channelActive(ChannelHandlerContext ctx)
                   throws Exception

Specified by:

channelActive in interface ChannelInboundHandler

Overrides:

channelActive in class ChannelInboundHandlerAdapter

Throws:

Exception

channelWritabilityChanged

public void channelWritabilityChanged(ChannelHandlerContext ctx)
                               throws Exception

Specified by:

channelWritabilityChanged in interface ChannelInboundHandler

Overrides:

channelWritabilityChanged in class ChannelInboundHandlerAdapter

Throws:

Exception

connect

public void connect(ChannelHandlerContext ctx,
                    SocketAddress remoteAddress,
                    SocketAddress localAddress,
                    ChannelPromise future)
             throws Exception

Specified by:

connect in interface ChannelOutboundHandler

Overrides:

connect in class ChannelDuplexHandler

Throws:

Exception

exceptionCaught

public void exceptionCaught(ChannelHandlerContext ctx,
                            Throwable cause)
                     throws Exception

Specified by:

exceptionCaught in interface ChannelHandler

Specified by:

exceptionCaught in interface ChannelInboundHandler

Overrides:

exceptionCaught in class ChannelInboundHandlerAdapter

Throws:

Exception

handlerRemoved

public void handlerRemoved(ChannelHandlerContext ctx)
                    throws Exception

Specified by:

handlerRemoved in interface ChannelHandler

Overrides:

handlerRemoved in class ChannelHandlerAdapter

Throws:

Exception

sideEffectRequestToCancel

protected void sideEffectRequestToCancel(REQUEST request)

This method can be overridden as it is called every time an operation is cancelled.

Overriding implementations may do some custom logic with them, for example freeing resources they know of to avoid leaking.

Parameters:

request - the request to side effect on.

userEventTriggered

public void userEventTriggered(ChannelHandlerContext ctx,
                               Object evt)
                        throws Exception

Specified by:

userEventTriggered in interface ChannelInboundHandler

Overrides:

userEventTriggered in class ChannelInboundHandlerAdapter

Throws:

Exception

createKeepAliveRequest

protected CouchbaseRequest createKeepAliveRequest()

Override to return a non-null request to be fired in the pipeline in case a keep alive is triggered.

Returns:

a CouchbaseRequest to be fired in case of keep alive (null by default).

onKeepAliveFired

protected void onKeepAliveFired(ChannelHandlerContext ctx,
                                CouchbaseRequest keepAliveRequest)

Override to customize the behavior when a keep alive has been triggered and a keep alive request sent.

The default behavior is to log the event at debug level.

Parameters:

ctx - the channel context.

keepAliveRequest - the keep alive request that was sent when keep alive was triggered

onKeepAliveResponse

protected void onKeepAliveResponse(ChannelHandlerContext ctx,
                                   CouchbaseResponse keepAliveResponse)

Override to customize the behavior when a keep alive has been responded to.

The default behavior is to log the event and the response status at trace level.

Parameters:

ctx - the channel context.

keepAliveResponse - the keep alive request that was sent when keep alive was triggered

currentRequest

protected REQUEST currentRequest()

Returns the current request if set.

Returns:

the current request.

currentRequest

protected void currentRequest(REQUEST request)

Sets current request.

FIXME this is temporary solution for DCPHandler

Parameters:

request - request to become the current one

remoteHostname

protected String remoteHostname()

Returns:

stringified version of the remote node’s hostname

env

protected CoreEnvironment env()

Returns environment.

Returns:

the environment

endpoint

protected AbstractEndpoint endpoint()

The parent endpoint.

logIdent

protected static String logIdent(ChannelHandlerContext ctx,
                                 Endpoint endpoint)

Simple log helper to give logs a common prefix.

Parameters:

ctx - the context.

endpoint - the endpoint.

Returns:

a prefix string for logs.

addHttpBasicAuth

public static void addHttpBasicAuth(ChannelHandlerContext ctx,
                                    HttpRequest request,
                                    String user,
                                    String password)

Add basic authentication headers to a HttpRequest.

The given information is Base64 encoded and the authorization header is set appropriately. Since this needs to be done for every request, it is refactored out.

Parameters:

ctx - the handler context.

request - the request where the header should be added.

user - the username for auth.

password - the password for auth.

remoteHttpHost

protected String remoteHttpHost(ChannelHandlerContext ctx)

Helper method to return the remote http host, cached.

Parameters:

ctx - the handler context.

Returns:

the remote http host.