Class ProtocolNegotiator

java.lang.Object

com.loomcache.common.protocol.ProtocolNegotiator

public final class ProtocolNegotiator
extends Object

Negotiates protocol version during peer handshake.

When two nodes connect, they perform a handshake to: 1. Exchange LoomVersion information (major.minor.patch) 2. Exchange protocol version integers 3. Determine compatibility 4. Confirm both peers use the single wire version supported by this build

This build does not include versioned codecs. Rolling upgrades are supported only when both peers advertise MessageCodec.PROTOCOL_VERSION. Feature flags may still disable optional behavior within that exact wire version.

Thread-safe: Each connection has one negotiator instance (used during handshake only).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	ProtocolNegotiator.IncompatibleVersionException	Exception thrown when version negotiation fails.

Constructor Summary

Constructors

Constructor	Description
ProtocolNegotiator(LoomVersion localVersion, int localProtocolVersion)	Create a protocol negotiator.

Method Summary

Modifier and Type	Method	Description
static ProtocolNegotiator	forCurrentVersion()	Create a negotiator with current version.
void	performHandshake(LoomVersion remoteVersion, int remoteProtocolVersion)	Perform version handshake with a remote peer.
void	performHandshake(LoomVersion remoteVersion, LoomVersion remoteMinCompatibleVersion, int remoteProtocolVersion)	Perform version handshake with a remote peer using the peer's advertised minimum compatible version.

Methods inherited from class Object

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

Constructor Details

ProtocolNegotiator

public ProtocolNegotiator(LoomVersion localVersion,
 int localProtocolVersion)

Create a protocol negotiator.

Parameters:

localVersion - the local LoomVersion (must not be null)

localProtocolVersion - the local protocol version (must be > 0)

Throws:

IllegalArgumentException - if localVersion is null or localProtocolVersion is invalid input: '<'= 0

Method Details

forCurrentVersion

public static ProtocolNegotiator forCurrentVersion()

Create a negotiator with current version.

Returns:

a new ProtocolNegotiator with current version

performHandshake

public void performHandshake(LoomVersion remoteVersion,
 int remoteProtocolVersion)

Perform version handshake with a remote peer.

When the remote peer's advertised minimum-compatible version is unavailable, this overload conservatively assumes the peer only accepts its current version.

Parameters:

remoteVersion - the remote node's LoomVersion (must not be null)

remoteProtocolVersion - the remote node's protocol version (must be > 0)

Throws:

ProtocolNegotiator.IncompatibleVersionException - if versions are incompatible

IllegalArgumentException - if parameters are invalid

performHandshake

public void performHandshake(LoomVersion remoteVersion,
 LoomVersion remoteMinCompatibleVersion,
 int remoteProtocolVersion)

Perform version handshake with a remote peer using the peer's advertised minimum compatible version.

Validates that: 1. The remote version satisfies the local minimum-compatible floor 2. The local version satisfies the remote minimum-compatible floor 3. Both sides agree on minimum protocol version 4. Negotiated protocol version is set for serialization

Rejects the handshake if versions are incompatible.

Parameters:

remoteVersion - the remote node's LoomVersion (must not be null)

remoteMinCompatibleVersion - the remote node's minimum compatible LoomVersion (must not be null)

remoteProtocolVersion - the remote node's protocol version (must be > 0)

Throws:

ProtocolNegotiator.IncompatibleVersionException - if versions are incompatible

IllegalArgumentException - if parameters are invalid