Graph.nodes() without given labels should return all nodes, not zero (

#159)
joernio · Mar 14, 2024 · 4c62caf · 4c62caf
1 parent 7cbc49b
commit 4c62caf
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Showing 2 changed files with 31 additions and 3 deletions.
diff --git a/core/src/main/scala/flatgraph/Graph.scala b/core/src/main/scala/flatgraph/Graph.scala
@@ -45,23 +45,28 @@ class Graph(val schema: Schema, val storagePathMaybe: Option[Path] = None) exten
   private[flatgraph] val livingNodeCountByKind: Array[Int] = new Array[Int](nodeKindCount)
 
   /** Note: this included `deleted` nodes! You might want to use `livingNodeCountByKind` instead. */
-  private[flatgraph] def nodeCountByKind(kind: Int): Int = nodesArray(kind).length
+  private[flatgraph] def nodeCountByKind(kind: Int): Int =
+    if (nodesArray.length <= kind) 0
+    else nodesArray(kind).length
 
   private[flatgraph] val properties     = new Array[AnyRef](nodeKindCount * propertiesCount * PropertySlotSize)
   private[flatgraph] val inverseIndices = new AtomicReferenceArray[Object](nodeKindCount * propertiesCount * PropertySlotSize)
   private[flatgraph] val nodesArray: Array[Array[GNode]] = makeNodesArray()
   private[flatgraph] val neighbors: Array[AnyRef]        = makeNeighbors()
 
   def _nodes(nodeKind: Int): InitNodeIterator[GNode] = {
-    if (nodeCountByKind(nodeKind) == livingNodeCountByKind(nodeKind)) new InitNodeIteratorArray[GNode](nodesArray(nodeKind))
+    if (nodeKind < 0 || schema.getNumberOfNodeKinds <= nodeKind) InitNodeIteratorArray(Array.empty[GNode])
+    else if (nodeCountByKind(nodeKind) == livingNodeCountByKind(nodeKind)) new InitNodeIteratorArray[GNode](nodesArray(nodeKind))
     else new InitNodeIteratorArrayFiltered[GNode](nodesArray(nodeKind))
   }
 
   def nodes(label: String): InitNodeIterator[GNode] =
     _nodes(schema.getNodeKindByLabel(label))
 
+  /** Lookup nodes for the given labels, or all nodes if no label is given (`.nodes()`) */
   def nodes(labels: String*): Iterator[GNode] =
-    labels.iterator.flatMap(nodes)
+    if (labels.isEmpty) allNodes
+    else labels.iterator.flatMap(nodes)
 
   /** Lookup node by id - note: this may return null or throw an exception if the referenced node doesn't exist */
   def node(id: Long): GNode =

diff --git a/core/src/test/scala/flatgraph/GraphTests.scala b/core/src/test/scala/flatgraph/GraphTests.scala
@@ -104,6 +104,29 @@ class GraphTests extends AnyWordSpec with Matchers {
     testSerialization(g)
   }
 
+  "some basic lookups" in {
+    val schema = TestSchema.make(2, 1)
+    val g      = new Graph(schema)
+    val V0_0   = new GenericDNode(0)
+    val V0_1   = new GenericDNode(0)
+    val V1_0   = new GenericDNode(1)
+    DiffGraphApplier.applyDiff(
+      g,
+      new DiffGraphBuilder(schema)
+        ._addEdge(V0_0, V0_0, 0)
+        ._addEdge(V0_1, V1_0, 0)
+    )
+
+    g.nodes().label.toSet shouldBe Set("V0", "V1")
+    g.allNodes.size shouldBe 3
+    g.nodes().size shouldBe 3
+    g.nodes("V0").size shouldBe 2
+    g.nodes("V1").size shouldBe 1
+    g.nodes("V0", "V1").size shouldBe 3
+    g.nodes("V0", "V1", "V2").size shouldBe 3
+    g.nodes("V2").size shouldBe 0
+  }
+
   "basically work with multiple edge and node types" in {
     val schema = TestSchema.make(3, 2)
     val g      = new Graph(schema)