Package org.opends.server.replication.protocol

Class ReplicationMsg

java.lang.Object

org.opends.server.replication.protocol.ReplicationMsg

Direct Known Subclasses:

AckMsg, ChangeStatusMsg, ChangeTimeHeartbeatMsg, HeartbeatMsg, MonitorMsg, MonitorRequestMsg, ResetGenerationIdMsg, RoutableMsg, StartMsg, StartSessionMsg, StopMsg, TopologyMsg, UpdateMsg, WindowMsg, WindowProbeMsg

public abstract class ReplicationMsg
extends Object

Abstract class that must be used when defining messages that can be sent for replication purpose between servers. When extending this class one should also create a new MSG_TYPE and should update the generateMsg() method.

Field Summary

Fields

Modifier and Type	Field	Description
static byte	MSG_TYPE_DISK_ENCODING	Reserved type for uses other than protocol messages.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	ReplicationMsg()	Protected constructor.

Method Summary

Modifier and Type	Method	Description
static ReplicationMsg	generateMsg(byte[] buffer, short protocolVersion)	Generates a ReplicationMsg from its encoded form.
abstract byte[]	getBytes(short protocolVersion)	Serializes the PDU using the provided replication protocol version.
boolean	isEncodableFor(short protocolVersion)	Whether this message has an encoding for a peer which negotiated the provided replication protocol version.

Methods inherited from class java.lang.Object

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

Field Detail

MSG_TYPE_DISK_ENCODING

public static final byte MSG_TYPE_DISK_ENCODING

Reserved type for uses other than protocol messages.

See Also:

Constant Field Values

Constructor Detail

ReplicationMsg

protected ReplicationMsg()

Protected constructor.

Method Detail

getBytes

public abstract byte[] getBytes(short protocolVersion)

Serializes the PDU using the provided replication protocol version. WARNING: should be overwritten by a PDU (sub class) we want to support older protocol version serialization for.

Parameters:

protocolVersion - The protocol version to use for serialization. The version should normally be older than the current one.

Returns:

The encoded PDU, or null if the message isn't supported in that protocol version.

isEncodableFor

public boolean isEncodableFor(short protocolVersion)

Whether this message has an encoding for a peer which negotiated the provided replication protocol version.

A message which has none is dropped by Session.publish(ReplicationMsg) - its getBytes(short) returns null - with nothing on the wire and nothing in the log, so a caller which goes on to report what the peer was told must ask this before it publishes.

Parameters:

protocolVersion - The protocol version negotiated with the peer.

Returns:

true if this message can be encoded for that version, false if it has no encoding for it at all.

generateMsg

public static ReplicationMsg generateMsg(byte[] buffer,
                                         short protocolVersion)
                                  throws DataFormatException,
                                         NotSupportedOldVersionPDUException

Generates a ReplicationMsg from its encoded form. This un-serialization is done taking into account the various supported replication protocol versions.

Parameters:

buffer - The encode form of the ReplicationMsg.

protocolVersion - The version to use to decode the msg.

Returns:

The generated SynchronizationMessage.

Throws:

DataFormatException - If the encoded form was not a valid msg.

NotSupportedOldVersionPDUException - If the PDU is part of an old protocol version and we do not support it.