radial sugiyama positioning integration

backend_go/graph_snapshot.go

@@ -168,40 +168,56 @@ func fetchGraphSnapshot(
 
 	nodes := acc.nodes
 	edges := acc.edges
+	routeSegments := []RouteSegment(nil)
+	layoutEngine := "go"
+	var layoutRootIRI *string
 
-	// Layout: invert edges for hierarchy (target -> source).
-	hierEdges := make([][2]int, 0, len(edges))
-	for _, e := range edges {
-		hierEdges = append(hierEdges, [2]int{int(e.Target), int(e.Source)})
-	}
-
-	layers, cycleErr := levelSynchronousKahnLayers(len(nodes), hierEdges)
-	if cycleErr != nil {
-		sample := make([]string, 0, 20)
-		for _, nid := range cycleErr.RemainingNodeIDs {
-			if len(sample) >= 20 {
-				break
-			}
-			if nid >= 0 && nid < len(nodes) {
-				sample = append(sample, nodes[nid].IRI)
-			}
+	if shouldUseRustHierarchyLayout(cfg, graphQueryID) {
+		layoutResult, err := layoutHierarchyWithRust(ctx, cfg, nodes, edges, preds)
+		if err != nil {
+			return GraphResponse{}, err
+		}
+		nodes = layoutResult.Nodes
+		edges = layoutResult.Edges
+		routeSegments = layoutResult.RouteSegments
+		layoutEngine = rustHierarchyLayoutEngineID
+		rootIRI := cfg.HierarchyLayoutRootIRI
+		layoutRootIRI = &rootIRI
+	} else {
+		// Layout: invert edges for hierarchy (target -> source).
+		hierEdges := make([][2]int, 0, len(edges))
+		for _, e := range edges {
+			hierEdges = append(hierEdges, [2]int{int(e.Target), int(e.Source)})
 		}
-		cycleErr.RemainingIRISample = sample
-		return GraphResponse{}, cycleErr
-	}
 
-	idToIRI := make([]string, len(nodes))
-	for i := range nodes {
-		idToIRI[i] = nodes[i].IRI
-	}
-	for _, layer := range layers {
-		sortLayerByIRI(layer, idToIRI)
-	}
+		layers, cycleErr := levelSynchronousKahnLayers(len(nodes), hierEdges)
+		if cycleErr != nil {
+			sample := make([]string, 0, 20)
+			for _, nid := range cycleErr.RemainingNodeIDs {
+				if len(sample) >= 20 {
+					break
+				}
+				if nid >= 0 && nid < len(nodes) {
+					sample = append(sample, nodes[nid].IRI)
+				}
+			}
+			cycleErr.RemainingIRISample = sample
+			return GraphResponse{}, cycleErr
+		}
 
-	xs, ys := radialPositionsFromLayers(len(nodes), layers, 5000.0)
-	for i := range nodes {
-		nodes[i].X = xs[i]
-		nodes[i].Y = ys[i]
+		idToIRI := make([]string, len(nodes))
+		for i := range nodes {
+			idToIRI[i] = nodes[i].IRI
+		}
+		for _, layer := range layers {
+			sortLayerByIRI(layer, idToIRI)
+		}
+
+		xs, ys := radialPositionsFromLayers(len(nodes), layers, 5000.0)
+		for i := range nodes {
+			nodes[i].X = xs[i]
+			nodes[i].Y = ys[i]
+		}
 	}
 
 	// Attach labels for URI nodes.
@@ -240,9 +256,11 @@ func fetchGraphSnapshot(
 		EdgeLimit:      edgeLimit,
 		Nodes:          len(nodes),
 		Edges:          len(edges),
+		LayoutEngine:   layoutEngine,
+		LayoutRootIRI:  layoutRootIRI,
 	}
 
-	return GraphResponse{Nodes: nodes, Edges: edges, Meta: meta}, nil
+	return GraphResponse{Nodes: nodes, Edges: edges, RouteSegments: routeSegments, Meta: meta}, nil
 }
 
 type bestLabel struct {