optimize topologic graph and add delete node func

diagram/topologic_set.go

@@ -1,54 +1,151 @@
 package diagram
 
 import (
+	"errors"
 	"fmt"
+	"sync"
+
+	"github.com/gofrs/uuid"
 )
 
 // Graph represents a topological structure using an adjacency list
 type Graph struct {
-	vertices map[string][]string
+	sync.RWMutex
+	// 根节点
+	rootVertex uuid.UUID
+	// 游离节点
+	freeVertexs  map[string]struct{}
+	verticeLinks map[string][]uuid.UUID
+	// 存储多个上级节点同时指向同一下级节点的情况,key为下级节点,value为上级节点集合
+	backLinks map[string][]uuid.UUID
 }
 
 // NewGraph creates a new graph
-// TODO 修改结构为map[uuid][]orm.Topologic
-func NewGraph() *Graph {
+func NewGraph(root uuid.UUID) *Graph {
 	return &Graph{
-		vertices: make(map[string][]string),
+		rootVertex:   root,
+		freeVertexs:  make(map[string]struct{}),
+		verticeLinks: make(map[string][]uuid.UUID),
+		backLinks:    make(map[string][]uuid.UUID),
 	}
 }
 
-// AddVertex adds a vertex to the graph
-func (g *Graph) AddVertex(vertex string) {
-	if _, exists := g.vertices[vertex]; !exists {
-		g.vertices[vertex] = []string{}
+// AddNode adds a node to the graph
+func (g *Graph) AddNode(vertex string) {
+	if _, exists := g.verticeLinks[vertex]; !exists {
+		g.verticeLinks[vertex] = []uuid.UUID{}
 	}
 }
 
-// AddEdge adds an edge between two vertices
-func (g *Graph) AddEdge(from, to string) {
-	g.AddVertex(from)
-	g.AddVertex(to)
-	g.vertices[from] = append(g.vertices[from], to)
+// CreateBackLink adds a node to the graph
+func (g *Graph) CreateBackLink(vertex string) {
+	if _, exists := g.backLinks[vertex]; !exists {
+		g.backLinks[vertex] = []uuid.UUID{}
+	}
+}
+
+// AddEdge adds an edge between two verticeLinks
+func (g *Graph) AddEdge(from, to uuid.UUID) {
+	g.Lock()
+	defer g.Unlock()
+
+	fromKey := from.String()
+	toKey := to.String()
+
+	g.CreateBackLink(toKey)
+	g.backLinks[toKey] = append(g.backLinks[toKey], from)
+
+	g.AddNode(fromKey)
+	g.AddNode(toKey)
+	g.verticeLinks[fromKey] = append(g.verticeLinks[fromKey], to)
+
+	// 创建新的拓扑信息时，如果被链接的点已经存在于游离节点中
+	// 则将其移除
+	if _, exist := g.freeVertexs[toKey]; exist {
+		delete(g.freeVertexs, toKey)
+	}
+}
+
+// DelNode delete a node to the graph
+func (g *Graph) DelNode(vertex string) error {
+	childNodes, exists := g.verticeLinks[vertex]
+	if exists {
+		if len(childNodes) > 1 {
+			return errors.New("delete node failed,that vertex contains more than one child node")
+		}
+		delete(g.verticeLinks, vertex)
+	}
+
+	parentNodes, exists := g.backLinks[vertex]
+	if exists {
+		if len(parentNodes) > 1 {
+			return errors.New("delete node failed,that vertex contains more than one parent node")
+		}
+		delete(g.backLinks, vertex)
+	} else {
+		return errors.New("that vertex don't have parent node")
+	}
+	return nil
+}
+
+// DelEdge delete an edge between two verticeLinks
+func (g *Graph) DelEdge(from, to uuid.UUID) error {
+	g.Lock()
+	defer g.Unlock()
+
+	toKey := to.String()
+	var fromKeys []uuid.UUID
+	if _, exist := g.backLinks[toKey]; exist {
+		fromKeys = g.backLinks[toKey]
+	} else {
+		fromKeys = []uuid.UUID{from}
+	}
+
+	childvertex := g.verticeLinks[toKey]
+	err := g.DelNode(toKey)
+	if err != nil {
+		return fmt.Errorf("delete edge failed: %w", err)
+	}
+
+	for _, fromUUID := range fromKeys {
+		fromKey := fromUUID.String()
+		var delIndex int
+		for index, vertex := range g.verticeLinks[fromKey] {
+			if vertex == to {
+				delIndex = index
+			}
+		}
+		vertex := g.verticeLinks[fromKey]
+		copy(vertex[delIndex:], vertex[delIndex+1:])
+		vertex = vertex[:len(vertex)-1]
+		g.verticeLinks[fromKey] = vertex
+	}
+
+	fromKey := from.String()
+	g.verticeLinks[fromKey] = append(g.verticeLinks[fromKey], childvertex...)
+	return nil
 }
 
 // PrintGraph prints the graph in adjacency list format
 func (g *Graph) PrintGraph() {
-	for vertex, edges := range g.vertices {
+	g.RLock() // 读锁
+	defer g.RUnlock()
+	for vertex, edges := range g.verticeLinks {
 		fmt.Printf("%s -> %v\n", vertex, edges)
 	}
 }
 
-func main() {
-	graph := NewGraph()
+// func main() {
+// 	graph := NewGraph()
 
-	// Add vertices and edges
-	graph.AddEdge("A", "B")
-	graph.AddEdge("A", "C")
-	graph.AddEdge("B", "D")
-	graph.AddEdge("C", "D")
-	graph.AddEdge("C", "E")
-	graph.AddEdge("E", "F")
+// 	// Add verticeLinks and edges
+// 	graph.AddEdge("A", "B")
+// 	graph.AddEdge("A", "C")
+// 	graph.AddEdge("B", "D")
+// 	graph.AddEdge("C", "D")
+// 	graph.AddEdge("C", "E")
+// 	graph.AddEdge("E", "F")
 
-	// Print the graph
-	graph.PrintGraph()
-}
+// 	// Print the graph
+// 	graph.PrintGraph()
+// }