Package net.minecraftforge.network

Class HandshakeHandler

java.lang.Object

net.minecraftforge.network.HandshakeHandler

public class HandshakeHandler
extends Object

Instance responsible for handling the overall FML impl handshake.

An instance is created during ClientIntentionPacket handling, and attached to the Connection.channel() via NetworkConstants.FML_HANDSHAKE_HANDLER.

The NetworkConstants.handshakeChannel is a SimpleChannel with standard messages flowing in both directions.

The loginWrapper transforms these messages into ServerboundCustomQueryPacket and ClientboundCustomQueryPacket compatible messages, by means of wrapping.

The handshake is ticked #tickLogin(NetworkManager) from the ServerLoginPacketListenerImpl.tick() method, utilizing the ServerLoginPacketListenerImpl.State#NEGOTIATING state, which is otherwise unused in vanilla code.

During client to server initiation, on the server, the NetworkEvent.GatherLoginPayloadsEvent is fired, which solicits all registered channels at the NetworkRegistry for any NetworkRegistry.LoginPayload they wish to supply.

The collected NetworkRegistry.LoginPayload are sent, one per tick, via the FMLLoginWrapper#wrapPacket(ResourceLocation, net.minecraft.impl.FriendlyByteBuf) mechanism to the incoming client connection. Each packet is indexed via ServerboundCustomQueryPacket.getTransactionId(), which is the only mechanism available for tracking request/response pairs.

Each packet sent from the server should be replied by the client, though not necessarily in sent order. The reply should contain the index of the server's packet it is replying to. The LoginWrapper class handles indexing replies correctly automatically.

Once all packets have been dispatched, we wait for all replies to be received. Once all replies are received, the final login phase will commence.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	HandshakeHandler.HandshakeConsumer<MSG extends IntSupplier>

Field Summary

Fields

Modifier and Type	Field	Description
private final NetworkDirection	direction
(package private) static final org.apache.logging.log4j.Marker	FMLHSMARKER
private static final org.apache.logging.log4j.Logger	LOGGER
private static final LoginWrapper	loginWrapper
private final Connection	manager
private List<NetworkRegistry.LoginPayload>	messageList
private boolean	negotiationStarted
private int	packetPosition
private final List<Future<Void>>	pendingFutures
private Set<ResourceLocation>	registriesToReceive
private Map<ResourceLocation,String>	registryHashes
private Map<ResourceLocation,ForgeRegistry.Snapshot>	registrySnapshots
private List<Integer>	sentMessages

Constructor Summary

Constructors

Modifier	Constructor	Description
private	HandshakeHandler(Connection networkManager, NetworkDirection side)

Method Summary

Modifier and Type	Method	Description
static <MSG extends IntSupplier> BiConsumer<MSG,Supplier<NetworkEvent.Context>>	biConsumerFor(HandshakeHandler.HandshakeConsumer<MSG> consumer)	Transforms a two-argument instance method reference into a BiConsumer based on the getHandshake(Supplier) function.
private static HandshakeHandler	getHandshake(Supplier<NetworkEvent.Context> contextSupplier)	Retrieve the handshake from the NetworkEvent.Context
(package private) void	handleClientAck(HandshakeMessages.C2SAcknowledge msg, Supplier<NetworkEvent.Context> contextSupplier)
(package private) void	handleClientModListOnServer(HandshakeMessages.C2SModListReply clientModList, Supplier<NetworkEvent.Context> c)
(package private) void	handleConfigSync(HandshakeMessages.S2CConfigData msg, Supplier<NetworkEvent.Context> contextSupplier)
(package private) <MSG extends IntSupplier> void	handleIndexedMessage(MSG message, Supplier<NetworkEvent.Context> c)
(package private) void	handleModData(HandshakeMessages.S2CModData serverModData, Supplier<NetworkEvent.Context> c)
(package private) void	handleModMismatchData(HandshakeMessages.S2CChannelMismatchData modMismatchData, Supplier<NetworkEvent.Context> c)
private boolean	handleRegistryLoading(Supplier<NetworkEvent.Context> contextSupplier)
(package private) void	handleRegistryMessage(HandshakeMessages.S2CRegistry registryPacket, Supplier<NetworkEvent.Context> contextSupplier)
(package private) void	handleServerModListOnClient(HandshakeMessages.S2CModList serverModList, Supplier<NetworkEvent.Context> c)
static <MSG extends IntSupplier> BiConsumer<MSG,Supplier<NetworkEvent.Context>>	indexFirst(HandshakeHandler.HandshakeConsumer<MSG> next)	Transforms a two-argument instance method reference into a BiConsumer biConsumerFor(HandshakeConsumer), first calling the handleIndexedMessage(IntSupplier, Supplier) method to handle index tracking.
static boolean	packetNeedsResponse(Connection mgr, int packetPosition)	Helper method to determine if the S2C packet at the given packet position needs a response in form of a packet handled in handleIndexedMessage(MSG, java.util.function.Supplier<net.minecraftforge.network.NetworkEvent.Context>) for the handshake to progress.
(package private) static void	registerHandshake(Connection manager, NetworkDirection direction)	Create a new handshake instance.
(package private) static boolean	tickLogin(Connection networkManager)
boolean	tickServer()	FML will send packets, from Server to Client, from the messages queue until the queue is drained.

Methods inherited from class java.lang.Object

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

Field Details

FMLHSMARKER

static final org.apache.logging.log4j.Marker FMLHSMARKER

LOGGER

private static final org.apache.logging.log4j.Logger LOGGER

loginWrapper

private static final LoginWrapper loginWrapper

messageList

private List<NetworkRegistry.LoginPayload> messageList

sentMessages

private List<Integer> sentMessages

direction

private final NetworkDirection direction

manager

private final Connection manager

packetPosition

private int packetPosition

registrySnapshots

private Map<ResourceLocation,ForgeRegistry.Snapshot> registrySnapshots

registriesToReceive

private Set<ResourceLocation> registriesToReceive

registryHashes

private Map<ResourceLocation,String> registryHashes

negotiationStarted

private boolean negotiationStarted

pendingFutures

private final List<Future<Void>> pendingFutures

Constructor Details

HandshakeHandler

private HandshakeHandler(Connection networkManager,
 NetworkDirection side)

Method Details

registerHandshake

static void registerHandshake(Connection manager,
 NetworkDirection direction)

Create a new handshake instance. Called when connection is first created during the ClientIntentionPacket handling.

Parameters:

manager - The impl manager for this connection

direction - The NetworkDirection for this connection: NetworkDirection.LOGIN_TO_SERVER or NetworkDirection.LOGIN_TO_CLIENT

tickLogin

static boolean tickLogin(Connection networkManager)

biConsumerFor

public static <MSG extends IntSupplier>
BiConsumer<MSG,Supplier<NetworkEvent.Context>> biConsumerFor(HandshakeHandler.HandshakeConsumer<MSG> consumer)

Transforms a two-argument instance method reference into a BiConsumer based on the getHandshake(Supplier) function. This should only be used for login message types.

Type Parameters:

MSG - message type

Parameters:

consumer - A two argument instance method reference

Returns:

A BiConsumer for use in message handling

indexFirst

public static <MSG extends IntSupplier>
BiConsumer<MSG,Supplier<NetworkEvent.Context>> indexFirst(HandshakeHandler.HandshakeConsumer<MSG> next)

Transforms a two-argument instance method reference into a BiConsumer biConsumerFor(HandshakeConsumer), first calling the handleIndexedMessage(IntSupplier, Supplier) method to handle index tracking. Used for client to server replies. This should only be used for login messages.

Type Parameters:

MSG - message type

Parameters:

next - The method reference to call after index handling

Returns:

A BiConsumer for use in message handling

getHandshake

private static HandshakeHandler getHandshake(Supplier<NetworkEvent.Context> contextSupplier)

Retrieve the handshake from the NetworkEvent.Context

Parameters:

contextSupplier - the NetworkEvent.Context

Returns:

The handshake handler for the connection

handleServerModListOnClient

void handleServerModListOnClient(HandshakeMessages.S2CModList serverModList,
 Supplier<NetworkEvent.Context> c)

handleModData

void handleModData(HandshakeMessages.S2CModData serverModData,
 Supplier<NetworkEvent.Context> c)

handleIndexedMessage

<MSG extends IntSupplier> void handleIndexedMessage(MSG message,
 Supplier<NetworkEvent.Context> c)

handleClientModListOnServer

void handleClientModListOnServer(HandshakeMessages.C2SModListReply clientModList,
 Supplier<NetworkEvent.Context> c)

handleModMismatchData

void handleModMismatchData(HandshakeMessages.S2CChannelMismatchData modMismatchData,
 Supplier<NetworkEvent.Context> c)

handleRegistryMessage

void handleRegistryMessage(HandshakeMessages.S2CRegistry registryPacket,
 Supplier<NetworkEvent.Context> contextSupplier)

handleRegistryLoading

private boolean handleRegistryLoading(Supplier<NetworkEvent.Context> contextSupplier)

handleClientAck

void handleClientAck(HandshakeMessages.C2SAcknowledge msg,
 Supplier<NetworkEvent.Context> contextSupplier)

handleConfigSync

void handleConfigSync(HandshakeMessages.S2CConfigData msg,
 Supplier<NetworkEvent.Context> contextSupplier)

tickServer

public boolean tickServer()

FML will send packets, from Server to Client, from the messages queue until the queue is drained. Each message will be indexed, and placed into the "pending acknowledgement" queue. As indexed packets are received at the server, they will be removed from the "pending acknowledgement" queue. Once the pending queue is drained, this method returns true - indicating that login processing can proceed to the next step.

Returns:

true if there is no more need to tick this login connection.

packetNeedsResponse

public static boolean packetNeedsResponse(Connection mgr,
 int packetPosition)

Helper method to determine if the S2C packet at the given packet position needs a response in form of a packet handled in handleIndexedMessage(MSG, java.util.function.Supplier<net.minecraftforge.network.NetworkEvent.Context>) for the handshake to progress.

Parameters:

mgr - The impl manager for this connection

packetPosition - The packet position of the packet that the status is queried of

Returns:

true if the packet at the given packet position needs a response and thus may stop the handshake from progressing