fix: the graph to show mandatory passthrough transformers on a new li…

…ne (#1014)

Signed-off-by: Harikrishnan Balagopal <[email protected]>

graph/layout.go

@@ -1,5 +1,5 @@
 /*
- *  Copyright IBM Corporation 2022
+ *  Copyright IBM Corporation 2023
  *
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -37,7 +37,7 @@ func GetNodesAndEdges(graph graphtypes.Graph) ([]graphtypes.Node, []graphtypes.E
 		}
 		node := graphtypes.Node{
 			Id:       fmt.Sprintf("v-%d", vertex.Id),
-			Position: graphtypes.Position{X: 0, Y: vertex.Iteration}, // store the iteration in the Y coordinate
+			Position: graphtypes.Position{X: 0, Y: vertex.Iteration}, // store the iteration in the Y coordinate (sub iterations in X coordinate)
 			Data:     graphtypes.Data{Label: vertex.Name, PathMappings: pathMappings},
 		}
 		if vertex.Id == 0 {
@@ -62,6 +62,31 @@ func GetNodesAndEdges(graph graphtypes.Graph) ([]graphtypes.Node, []graphtypes.E
 	return nodes, edges
 }
 
+type graphIterAndSubIter struct {
+	Iter int
+	Sub  int
+}
+
+type graphSortIters struct {
+	Items []graphIterAndSubIter
+}
+
+// Len is the number of elements in the collection.
+func (x *graphSortIters) Len() int {
+	return len(x.Items)
+}
+
+// Less reports whether the element with index i
+// must sort before the element with index j.
+func (x *graphSortIters) Less(i, j int) bool {
+	return x.Items[i].Iter < x.Items[j].Iter || (x.Items[i].Iter == x.Items[j].Iter && x.Items[i].Sub < x.Items[j].Sub)
+}
+
+// Swap swaps the elements with indexes i and j.
+func (x *graphSortIters) Swap(i, j int) {
+	x.Items[i], x.Items[j] = x.Items[j], x.Items[i]
+}
+
 // BfsUpdatePositions updates the positions of the nodes using a layered layout algorithm that utilizes Breadth First Search.
 func BfsUpdatePositions(nodes []graphtypes.Node, edges []graphtypes.EdgeT) {
 	adjMat := map[string]map[string]struct{}{}
@@ -72,39 +97,56 @@ func BfsUpdatePositions(nodes []graphtypes.Node, edges []graphtypes.EdgeT) {
 		adjMat[edge.Source][edge.Target] = struct{}{}
 	}
 
-	// the bread first search algorithm
-	queue := []string{"v-0"}
+	iterSubIterToY := map[graphIterAndSubIter]int{}
+	{
+		// depth first search to calculate sub-iterations
+		subIters := map[graphIterAndSubIter]struct{}{}
+		visited := map[string]struct{}{"v-0": {}}
+		dfsRecursive(nodes, subIters, visited, adjMat, "v-0", -1)
+		sortIters := graphSortIters{}
+		for subIter := range subIters {
+			sortIters.Items = append(sortIters.Items, subIter)
+		}
+		sort.Stable(&sortIters)
+		for i, x := range sortIters.Items {
+			iterSubIterToY[x] = i * 200
+		}
+	}
+
 	visited := map[string]struct{}{"v-0": {}}
-	xsPerIteration := map[int]int{}
-	for len(queue) > 0 {
-		// pop a vertex from the queue
-		current := queue[0]
-		queue = queue[1:]
-		// add its neighbours to the queue for processing later
-		neighbours := adjMat[current]
-		sortedNotVisitedNeighbours := []string{}
-		for neighbour := range neighbours {
-			if _, ok := visited[neighbour]; !ok {
-				sortedNotVisitedNeighbours = append(sortedNotVisitedNeighbours, neighbour)
-				visited[neighbour] = struct{}{}
+	iterSubIterToX := map[graphIterAndSubIter]int{}
+	{
+		// the bread first search algorithm
+		queue := []string{"v-0"}
+		for len(queue) > 0 {
+			// pop a vertex from the queue
+			current := queue[0]
+			queue = queue[1:]
+			// add its neighbours to the queue for processing later
+			neighbours := adjMat[current]
+			sortedNotVisitedNeighbours := []string{}
+			for neighbour := range neighbours {
+				if _, ok := visited[neighbour]; !ok {
+					sortedNotVisitedNeighbours = append(sortedNotVisitedNeighbours, neighbour)
+					visited[neighbour] = struct{}{}
+				}
 			}
+			sort.StringSlice(sortedNotVisitedNeighbours).Sort()
+			queue = append(queue, sortedNotVisitedNeighbours...)
+			// calculate the new position for the current node
+			idx := common.FindIndex(nodes, func(n graphtypes.Node) bool { return n.Id == current })
+			if idx < 0 {
+				logrus.Errorf("failed to find a node for the vertex with id '%s'", current)
+				continue
+			}
+			node := nodes[idx]
+			ii := graphIterAndSubIter{Iter: node.Position.Y, Sub: node.Position.X}
+			newX := iterSubIterToX[ii]
+			iterSubIterToX[ii] = newX + 200
+			node.Position.X = newX
+			node.Position.Y = iterSubIterToY[ii]
+			nodes[idx] = node
 		}
-		sort.StringSlice(sortedNotVisitedNeighbours).Sort()
-		queue = append(queue, sortedNotVisitedNeighbours...)
-		// calculate the new position for the current node
-		idx := common.FindIndex(nodes, func(n graphtypes.Node) bool { return n.Id == current })
-		if idx < 0 {
-			logrus.Errorf("failed to find a node for the vertex with id '%s'", current)
-			continue
-		}
-		node := nodes[idx]
-		iteration := node.Position.Y
-		newX := xsPerIteration[iteration]
-		xsPerIteration[iteration] = newX + 200
-		newY := iteration * 200
-		node.Position.X = newX
-		node.Position.Y = newY
-		nodes[idx] = node
 	}
 
 	// handle islands
@@ -115,12 +157,46 @@ func BfsUpdatePositions(nodes []graphtypes.Node, edges []graphtypes.EdgeT) {
 		logrus.Errorf("found an unvisited node: %+v", node)
 		visited[node.Id] = struct{}{}
 		// calculate the new position for the current node
-		iteration := node.Position.Y
-		newX := xsPerIteration[iteration]
-		xsPerIteration[iteration] = newX + 200
-		newY := iteration * 200
+		ii := graphIterAndSubIter{Iter: node.Position.Y, Sub: node.Position.X}
+		newX := iterSubIterToX[ii]
+		iterSubIterToX[ii] = newX + 200
 		node.Position.X = newX
-		node.Position.Y = newY
+		node.Position.Y = iterSubIterToY[ii]
 		nodes[i] = node
 	}
 }
+
+func dfsRecursive(
+	nodes []graphtypes.Node,
+	subIters map[graphIterAndSubIter]struct{},
+	visited map[string]struct{},
+	adjMat map[string]map[string]struct{},
+	current string,
+	parentIdx int,
+) {
+	visited[current] = struct{}{}
+	currentIdx := common.FindIndex(nodes, func(n graphtypes.Node) bool { return n.Id == current })
+	if currentIdx < 0 {
+		logrus.Errorf("failed to find the vertex with id '%s' in the list of nodes", current)
+		return
+	}
+	// calculate sub-iteration
+	currentNode := nodes[currentIdx]
+	if parentIdx >= 0 {
+		parentNode := nodes[parentIdx]
+		parentIteration := parentNode.Position.Y
+		currentIteration := currentNode.Position.Y
+		if parentIteration == currentIteration {
+			// store the sub iteration in the X coordinate
+			currentNode.Position.X = parentNode.Position.X + 1
+			nodes[currentIdx] = currentNode
+		}
+	}
+	subIters[graphIterAndSubIter{Iter: currentNode.Position.Y, Sub: currentNode.Position.X}] = struct{}{}
+	neighbours := adjMat[current]
+	for neighbour := range neighbours {
+		if _, ok := visited[neighbour]; !ok {
+			dfsRecursive(nodes, subIters, visited, adjMat, neighbour, currentIdx)
+		}
+	}
+}

types/graph/graph.go

@@ -28,10 +28,11 @@ type Graph struct {
 
 // Vertex is a single transformer.
 type Vertex struct {
-	Id        int                    `json:"id"`
-	Iteration int                    `json:"iteration"`
-	Name      string                 `json:"name"`
-	Data      map[string]interface{} `json:"data,omitempty"`
+	Id           int                    `json:"id"`
+	Iteration    int                    `json:"iteration"`
+	SubIteration int                    `json:"subiteration"`
+	Name         string                 `json:"name"`
+	Data         map[string]interface{} `json:"data,omitempty"`
 }
 
 // Edge is an artifact.