com.netflix.hollow.tools.traverse

Class TransitiveSetTraverser

java.lang.Object

com.netflix.hollow.tools.traverse.TransitiveSetTraverser

public class TransitiveSetTraverser
extends java.lang.Object

The TransitiveSetTraverser can be used to find children and parent references for a selected set of records. A selection is represented with a Map<String, BitSet>, where each key in the map represents a type, and the corresponding BitSet represents the ordinals of the selected records. Entries in this Map will indicate a type, plus the ordinals of the selected records:

 
 Map<String, BitSet> selection = new HashMap<String, BitSet>();
  
 /// select the movies with ordinals 1 and 4.
 BitSet selectedMovies = new BitSet();
 selectedMovies.set(1);
 selectedMovies.set(4);
  
 selection.put("Movie", movies);
 
 

We can add the references, and the transitive references, of our selection. After the following call returns, our selection will be augmented with these matches:

  TransitiveSetTraverser.addTransitiveMatches(readEngine, selection);
 

Given a selection, we can also add any records which reference anything in the selection. This is essentially the opposite operation as above; it can be said that addTransitiveMatches traverses down, while addReferencingOutsideClosure traverses up. After the following call returns, our selection will be augmented with this selection:

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	TransitiveSetTraverser.TransitiveSetTraverserAction

Constructor Summary

Constructors

Constructor and Description
TransitiveSetTraverser()

Method Summary

Modifier and Type	Method and Description
static void	addReferencingOutsideClosure(HollowReadStateEngine stateEngine, java.util.Map<java.lang.String,java.util.BitSet> matches) Augment the given selection with any records outside the selection which reference (or transitively reference) any records in the selection.
static void	addTransitiveMatches(HollowReadStateEngine stateEngine, java.util.Map<java.lang.String,java.util.BitSet> matches) Augment the given selection by adding the references, and the transitive references, of our selection.
static void	removeReferencedOutsideClosure(HollowReadStateEngine stateEngine, java.util.Map<java.lang.String,java.util.BitSet> matches) Remove any records from the given selection which are referenced by other records not in the selection.

Methods inherited from class java.lang.Object

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

Constructor Detail

TransitiveSetTraverser

public TransitiveSetTraverser()

Method Detail

addTransitiveMatches

public static void addTransitiveMatches(HollowReadStateEngine stateEngine,
                                        java.util.Map<java.lang.String,java.util.BitSet> matches)

Augment the given selection by adding the references, and the transitive references, of our selection.

Parameters:

stateEngine - the state engine

matches - the map to which matches are placed

removeReferencedOutsideClosure

public static void removeReferencedOutsideClosure(HollowReadStateEngine stateEngine,
                                                  java.util.Map<java.lang.String,java.util.BitSet> matches)

Remove any records from the given selection which are referenced by other records not in the selection.

Parameters:

stateEngine - the state engine

matches - the matches

addReferencingOutsideClosure

public static void addReferencingOutsideClosure(HollowReadStateEngine stateEngine,
                                                java.util.Map<java.lang.String,java.util.BitSet> matches)

Augment the given selection with any records outside the selection which reference (or transitively reference) any records in the selection.

Parameters:

stateEngine - the state engine

matches - the matches