LogIndex

java.lang.Object
- org.eclipse.jgit.lib.AnyObjectId
- - org.eclipse.jgit.lib.ObjectId
  - - org.eclipse.jgit.internal.ketch.LogIndex

All Implemented Interfaces:

java.io.Serializable, java.lang.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

Field Summary

Fields
Modifier and Type Field Description

private long index

Constructor Summary

Constructors
Modifier Constructor Description

private LogIndex(AnyObjectId id, long index)

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`java.lang.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.
`(package private) boolean`	`isBefore(LogIndex c)`	Check if this log position committed before another log position.
`(package private) LogIndex`	`nextIndex(AnyObjectId id)`
`java.lang.String`	`toString()`
`(package private) static LogIndex`	`unknown(AnyObjectId id)`

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, isEqual, name, startsWith

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - index
```
private final long index
```
- Constructor Detail
  - LogIndex
```
private LogIndex(AnyObjectId id,
                 long index)
```
- Method Detail
  - unknown
```
static LogIndex unknown(AnyObjectId id)
```
  - nextIndex
```
LogIndex nextIndex(AnyObjectId id)
```
  - getIndex
```
public long getIndex()
```
    Get index provided by the current leader instance.
    
    Returns:
    
    index provided by the current leader instance.
  - isBefore
```
boolean isBefore(LogIndex c)
```
    Check if this log position committed before another log position.
    Only valid for log positions in memory for the current leader.
    
    Parameters:
    
    c - other (more recent) log position.
    
    Returns:
    
    true if this log position was before c or equal to c and therefore any agreement of c implies agreement on this log position.
  - describeForLog
```
public java.lang.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 java.lang.String toString()
```
    Overrides:
    
    toString in class AnyObjectId