service map graph structure

agent/pkg/api/service_map.go

@@ -0,0 +1,75 @@
+package api
+
+import (
+	"fmt"
+)
+
+const UnresolvedNode = "unresolved"
+
+type id string
+type edgeData struct {
+	count int
+}
+
+type graph struct {
+	Nodes map[id]struct{}
+	Edges map[id]map[id]*edgeData
+}
+
+func NewDirectedGraph() *graph {
+	return &graph{
+		Nodes: make(map[id]struct{}),
+		Edges: make(map[id]map[id]*edgeData),
+	}
+}
+
+func (g *graph) addNode(id id) {
+	if _, ok := g.Nodes[id]; ok {
+		return
+	}
+	g.Nodes[id] = struct{}{}
+}
+
+func (g *graph) AddEdge(u, v id) {
+	if len(u) == 0 {
+		u = UnresolvedNode
+	}
+	if len(v) == 0 {
+		v = UnresolvedNode
+	}
+
+	if _, ok := g.Nodes[u]; !ok {
+		g.addNode(u)
+	}
+	if _, ok := g.Nodes[v]; !ok {
+		g.addNode(v)
+	}
+
+	if _, ok := g.Edges[u]; !ok {
+		g.Edges[u] = make(map[id]*edgeData)
+	}
+
+	if e, ok := g.Edges[u][v]; ok {
+		e.count++
+	} else {
+		g.Edges[u][v] = &edgeData{count: 1}
+	}
+}
+
+func (g *graph) PrintNodes() {
+	fmt.Println("Printing all nodes...")
+
+	for k := range g.Nodes {
+		fmt.Printf("Node: %v\n", k)
+	}
+}
+
+func (g *graph) PrintAdjacentEdges() {
+	fmt.Println("Printing all edges...")
+	for u, m := range g.Edges {
+		for v := range m {
+			// Edge exists from u to v.
+			fmt.Printf("Edge: %v -> %v - Count: %v\n", u, v, g.Edges[u][v].count)
+		}
+	}
+}