Package io.permazen.kv.raft.msg

Class AppendResponse

java.lang.Object

io.permazen.kv.raft.msg.Message

io.permazen.kv.raft.msg.AppendResponse

public class AppendResponse
extends Message

Sent from a follower to a leader in response to an AppendRequest.

Also contains information about the follower's log.

Constructor Summary

Constructors

Constructor	Description
AppendResponse(int clusterId, String senderId, String recipientId, long term, Timestamp leaderTimestamp, boolean success, long matchIndex, long lastLogIndex)	Constructor.

Method Summary

Modifier and Type	Method	Description
protected int	calculateSize(int version)	Calculate an upper bound on the number of bytes required by writeTo().
long	getLastLogIndex()	Get the index of the last log entry in the follower's log.
Timestamp	getLeaderTimestamp()	Get the leaderTimestamp from the corresponding AppendRequest.
long	getMatchIndex()	Get the index of the most recent log entry known to match leader.
boolean	isSuccess()	Determine whether the request was successful, i.e., the previous log entry term and index matched.
String	toString()
void	visit(MessageSwitch handler)	Apply the visitor pattern based on this instance's type.
void	writeTo(ByteBuffer dest, int version)	Serialize this instance into the given buffer.

Methods inherited from class io.permazen.kv.raft.msg.Message

calculateSize, calculateSize, calculateSize, decode, decodeProtocolVersion, encode, getBoolean, getByteBuffer, getClusterId, getCurrentProtocolVersion, getRecipientId, getSenderId, getString, getTerm, getTimestamp, isLeaderMessage, putBoolean, putByteBuffer, putString, putTimestamp

Methods inherited from class java.lang.Object

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

Constructor Details

AppendResponse

public AppendResponse(int clusterId,
 String senderId,
 String recipientId,
 long term,
 Timestamp leaderTimestamp,
 boolean success,
 long matchIndex,
 long lastLogIndex)

Constructor.

Parameters:

clusterId - cluster ID

senderId - identity of sender

recipientId - identity of recipient

term - sender's current term

leaderTimestamp - copy of AppendRequest.getLeaderTimestamp()

success - if request successfully matched

matchIndex - highest known matching log index

lastLogIndex - index of follower's last log entry

Method Details

getLeaderTimestamp

public Timestamp getLeaderTimestamp()

Get the leaderTimestamp from the corresponding AppendRequest.

Returns:

request leader timestamp

See Also:

• AppendRequest.getLeaderTimestamp()

isSuccess

public boolean isSuccess()

Determine whether the request was successful, i.e., the previous log entry term and index matched.

Returns:

true if the corresponding request matched

getMatchIndex

public long getMatchIndex()

Get the index of the most recent log entry known to match leader. In case of a successful request, this will be equal to the log entry sent (or the previous log entry in case of a probe). In case of a failed request, this will be equal to the follower's state machine last applied index.

Returns:

highest known matching log entry index

getLastLogIndex

public long getLastLogIndex()

Get the index of the last log entry in the follower's log.

Returns:

last log entry index

visit

public void visit(MessageSwitch handler)

Description copied from class: Message

Apply the visitor pattern based on this instance's type.

Specified by:

visit in class Message

Parameters:

handler - target for visit

writeTo

public void writeTo(ByteBuffer dest,
 int version)

Description copied from class: Message

Serialize this instance into the given buffer.

Overrides:

writeTo in class Message

Parameters:

dest - destination for encoded data

version - protocol encoding version number

calculateSize

protected int calculateSize(int version)

Description copied from class: Message

Calculate an upper bound on the number of bytes required by writeTo().

Overrides:

calculateSize in class Message

Parameters:

version - protocol encoding version

Returns:

an upper bound on the number of encoded bytes

toString

public String toString()

Specified by:

toString in class Message