KnnGraphValues (Lucene 9.0.0 core API)

java.lang.Object
- org.apache.lucene.index.KnnGraphValues

Direct Known Subclasses:

HnswGraph
```
public abstract class KnnGraphValues
extends Object
```
Access to per-document neighbor lists in a (hierarchical) knn search graph.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Field Summary

Fields
Modifier and Type Field Description

static KnnGraphValues EMPTY
Empty graph value

Constructor Summary

Constructors
Modifier Constructor Description

protected KnnGraphValues()
Sole constructor

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`abstract int`	`nextNeighbor()`	Iterates over the neighbor list.
`abstract void`	`seek(int target)`	Move the pointer to exactly `target`, the id of a node in the graph.
`abstract int`	`size()`	Returns the number of nodes in the graph

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

- Field Detail
  - EMPTY
```
public static KnnGraphValues EMPTY
```
    Empty graph value
- Constructor Detail
  - KnnGraphValues
```
protected KnnGraphValues()
```
    Sole constructor
- Method Detail
  - seek
```
public abstract void seek(int target)
                   throws IOException
```
    Move the pointer to exactly target, the id of a node in the graph. After this method returns, call nextNeighbor() to return successive (ordered) connected node ordinals.
    
    Parameters:
    
    target - must be a valid node in the graph, ie. ≥ 0 and < VectorValues.size().
    
    Throws:
    
    IOException
  - size
```
public abstract int size()
```
    Returns the number of nodes in the graph
  - nextNeighbor
```
public abstract int nextNeighbor()
                          throws IOException
```
    Iterates over the neighbor list. It is illegal to call this method after it returns NO_MORE_DOCS without calling seek(int), which resets the iterator.
    
    Returns:
    
    a node ordinal in the graph, or NO_MORE_DOCS if the iteration is complete.
    
    Throws:
    
    IOException