HnswUtil (Lucene 9.12.2 core API)

java.lang.Object
- org.apache.lucene.util.hnsw.HnswUtil

```
public class HnswUtil
extends Object
```
Utilities for use in tests involving HNSW graphs

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static boolean`	`graphIsRooted(IndexReader reader, String vectorField)`	In graph theory, "connected components" are really defined only for undirected (ie bidirectional) graphs.

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

- Method Detail
  - graphIsRooted
```
public static boolean graphIsRooted(IndexReader reader,
                                    String vectorField)
                             throws IOException
```
    In graph theory, "connected components" are really defined only for undirected (ie bidirectional) graphs. Our graphs are directed, because of pruning, but they are *mostly* undirected. In this case we compute components starting from a single node so what we are really measuring is whether the graph is a "rooted graph". TODO: measure whether the graph is "strongly connected" ie there is a path from every node to every other node.
    
    Throws:
    
    IOException