Package com.linkedin.davinci.blobtransfer.server

Class P2PFileTransferServerHandler

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.channel.SimpleChannelInboundHandler<io.netty.handler.codec.http.FullHttpRequest>

com.linkedin.davinci.blobtransfer.server.P2PFileTransferServerHandler

All Implemented Interfaces:

io.netty.channel.ChannelHandler, io.netty.channel.ChannelInboundHandler

@Sharable
public class P2PFileTransferServerHandler
extends io.netty.channel.SimpleChannelInboundHandler<io.netty.handler.codec.http.FullHttpRequest>

The server-side Netty handler to process requests for P2P file transfer. It's shareable among multiple requests since it doesn't maintain states.

Nested Class Summary

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

io.netty.channel.ChannelHandler.Sharable

Constructor Summary

Constructors

Constructor	Description
P2PFileTransferServerHandler(String baseDir, int blobTransferMaxTimeoutInMin, BlobSnapshotManager blobSnapshotManager, int maxAllowedConcurrentSnapshotUsers)

Method Summary

Modifier and Type	Method	Description
void	channelInactive(io.netty.channel.ChannelHandlerContext ctx)	This method is called when the channel is inactive.
protected void	channelRead0(io.netty.channel.ChannelHandlerContext ctx, io.netty.handler.codec.http.FullHttpRequest httpRequest)	This method is called with the request that is received from the client.
void	exceptionCaught(io.netty.channel.ChannelHandlerContext ctx, Throwable cause)
void	sendMetadata(io.netty.channel.ChannelHandlerContext ctx, BlobTransferPartitionMetadata metadata)	Send metadata for the given blob transfer request
void	userEventTriggered(io.netty.channel.ChannelHandlerContext ctx, Object event)	Netty calls this function when events that we have registered for, occur (in this case we are specifically waiting for IdleStateEvent so that we close connections that have been idle too long - maybe due to client failure)

Methods inherited from class io.netty.channel.SimpleChannelInboundHandler

acceptInboundMessage, channelRead

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter

channelActive, channelReadComplete, channelRegistered, channelUnregistered, channelWritabilityChanged

Methods inherited from class 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 io.netty.channel.ChannelHandler

handlerAdded, handlerRemoved

Constructor Details

P2PFileTransferServerHandler

public P2PFileTransferServerHandler(String baseDir,
 int blobTransferMaxTimeoutInMin,
 BlobSnapshotManager blobSnapshotManager,
 int maxAllowedConcurrentSnapshotUsers)

Method Details

channelRead0

protected void channelRead0(io.netty.channel.ChannelHandlerContext ctx,
 io.netty.handler.codec.http.FullHttpRequest httpRequest)
                     throws Exception

This method is called with the request that is received from the client. It validates the incoming request, and currently it only supports GET

Specified by:

channelRead0 in class io.netty.channel.SimpleChannelInboundHandler<io.netty.handler.codec.http.FullHttpRequest>

Parameters:

ctx - the ChannelHandlerContext which this SimpleChannelInboundHandler belongs to

httpRequest - the message to handle

Throws:

Exception

channelInactive

public void channelInactive(io.netty.channel.ChannelHandlerContext ctx)

This method is called when the channel is inactive. It is used to decrease the concurrent user count. Because the channel is inactive, we can assume that the transfer is complete. If we decrease the concurrent user at channelRead0, when the connection is break in half, we will not be able to decrease the count in server side

Specified by:

channelInactive in interface io.netty.channel.ChannelInboundHandler

Overrides:

channelInactive in class io.netty.channel.ChannelInboundHandlerAdapter

Parameters:

ctx -

userEventTriggered

public void userEventTriggered(io.netty.channel.ChannelHandlerContext ctx,
 Object event)
                        throws Exception

Netty calls this function when events that we have registered for, occur (in this case we are specifically waiting for IdleStateEvent so that we close connections that have been idle too long - maybe due to client failure)

Specified by:

userEventTriggered in interface io.netty.channel.ChannelInboundHandler

Overrides:

userEventTriggered in class io.netty.channel.ChannelInboundHandlerAdapter

Parameters:

ctx - The ChannelHandlerContext that can be used to perform operations on the channel.

event - The event that occurred.

Throws:

Exception

exceptionCaught

public void exceptionCaught(io.netty.channel.ChannelHandlerContext ctx,
 Throwable cause)
                     throws Exception

Specified by:

exceptionCaught in interface io.netty.channel.ChannelHandler

Specified by:

exceptionCaught in interface io.netty.channel.ChannelInboundHandler

Overrides:

exceptionCaught in class io.netty.channel.ChannelInboundHandlerAdapter

Throws:

Exception

sendMetadata

public void sendMetadata(io.netty.channel.ChannelHandlerContext ctx,
 BlobTransferPartitionMetadata metadata)
                  throws com.fasterxml.jackson.core.JsonProcessingException

Send metadata for the given blob transfer request

Parameters:

ctx - the channel context

metadata - the metadata to be sent

Throws:

com.fasterxml.jackson.core.JsonProcessingException