org.eclipse.jgit.internal.ketch

Class LogIndex

java.lang.Object

org.eclipse.jgit.lib.AnyObjectId

org.eclipse.jgit.lib.ObjectId

org.eclipse.jgit.internal.ketch.LogIndex

All Implemented Interfaces:

Serializable, Comparable<AnyObjectId>

public class LogIndex
extends ObjectId

An ObjectId for a commit extended with incrementing log index.

For any two LogIndex instances, A is an ancestor of C reachable through parent edges in the graph if A.index < C.index. LogIndex provides a performance optimization for Ketch, the same information can be obtained from RevWalk.

Index values are only valid within a single KetchLeader instance after it has won an election. By restricting scope to a single leader new leaders do not need to traverse the entire history to determine the next index for new proposals. This differs from Raft, where leader election uses the log index and the term number to determine which replica holds a sufficiently up-to-date log. Since Ketch uses Git objects for storage of its replicated log, it keeps the term number as Raft does but uses standard Git operations to imply the log index.

Round.runAsync(AnyObjectId) bumps the index as each new round is constructed.

See Also:

Serialized Form

Method Summary

Modifier and Type	Method and Description
String	describeForLog() Create string suitable for debug logging containing the log index and abbreviated ObjectId.
long	getIndex() Get index provided by the current leader instance.
String	toString()

Methods inherited from class org.eclipse.jgit.lib.ObjectId

equals, fromRaw, fromRaw, fromRaw, fromRaw, fromString, fromString, isId, toObjectId, toString, zeroId

Methods inherited from class org.eclipse.jgit.lib.AnyObjectId

abbreviate, compareTo, compareTo, compareTo, copy, copyRawTo, copyRawTo, copyRawTo, copyRawTo, copyTo, copyTo, copyTo, copyTo, copyTo, copyTo, equals, equals, equals, getByte, getFirstByte, getName, hashCode, name, startsWith

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

getIndex

public long getIndex()

Get index provided by the current leader instance.

Returns:

index provided by the current leader instance.

describeForLog

public String describeForLog()

Create string suitable for debug logging containing the log index and abbreviated ObjectId.

Returns:

string suitable for debug logging containing the log index and abbreviated ObjectId.

toString

public String toString()

Overrides:

toString in class AnyObjectId