feat: add example

dag/dag.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"log"
 	"net/http"
+	"strings"
 	"sync"
 	"time"
 
@@ -24,11 +25,11 @@ func NewTask(id string, payload json.RawMessage, nodeKey string) *mq.Task {
 
 type EdgeType int
 
-func (c EdgeType) IsValid() bool { return c >= SimpleEdge && c <= LoopEdge }
+func (c EdgeType) IsValid() bool { return c >= Simple && c <= Iterator }
 
 const (
-	SimpleEdge EdgeType = iota
-	LoopEdge
+	Simple EdgeType = iota
+	Iterator
 )
 
 type Node struct {
@@ -50,8 +51,9 @@ type Edge struct {
 }
 
 type (
-	When string
-	Then string
+	FromNode string
+	When     string
+	Then     string
 )
 
 type DAG struct {
@@ -59,7 +61,7 @@ type DAG struct {
 	nodes       map[string]*Node
 	server      *mq.Broker
 	taskContext map[string]*TaskManager
-	conditions  map[string]map[When]Then
+	conditions  map[FromNode]map[When]Then
 	mu          sync.RWMutex
 	paused      bool
 	opts        []mq.Option
@@ -69,7 +71,7 @@ func NewDAG(opts ...mq.Option) *DAG {
 	d := &DAG{
 		nodes:       make(map[string]*Node),
 		taskContext: make(map[string]*TaskManager),
-		conditions:  make(map[string]map[When]Then),
+		conditions:  make(map[FromNode]map[When]Then),
 	}
 	opts = append(opts, mq.WithCallback(d.onTaskCallback), mq.WithConsumerOnSubscribe(d.onConsumerJoin), mq.WithConsumerOnClose(d.onConsumerClose))
 	d.server = mq.NewBroker(opts...)
@@ -77,6 +79,99 @@ func NewDAG(opts ...mq.Option) *DAG {
 	return d
 }
 
+// PrintGraph prints the DAG's adjacency list
+func (tm *DAG) PrintGraph() {
+	tm.mu.RLock()
+	defer tm.mu.RUnlock()
+
+	fmt.Println("DAG Graph structure:")
+	for _, node := range tm.nodes {
+		fmt.Printf("Node: %s (%s) -> ", node.Name, node.Key)
+		if conditions, ok := tm.conditions[FromNode(node.Key)]; ok {
+			var c []string
+			for when, then := range conditions {
+				if target, ok := tm.nodes[string(then)]; ok {
+					c = append(c, fmt.Sprintf("If [%s] Then %s (%s)", when, target.Name, target.Key))
+				}
+			}
+			fmt.Println(strings.Join(c, ", "))
+		}
+		var c []string
+		for _, edge := range node.Edges {
+			for _, target := range edge.To {
+				c = append(c, fmt.Sprintf("%s (%s)", target.Name, target.Key))
+			}
+		}
+		fmt.Println(strings.Join(c, ", "))
+	}
+}
+
+func (tm *DAG) ClassifyEdges(startNodes ...string) {
+	startNode := tm.GetStartNode()
+	tm.mu.RLock()
+	defer tm.mu.RUnlock()
+	if len(startNodes) > 0 && startNodes[0] != "" {
+		startNode = startNodes[0]
+	}
+	visited := make(map[string]bool)
+	discoveryTime := make(map[string]int)
+	finishedTime := make(map[string]int)
+	timeVal := 0
+	if startNode == "" {
+		firstNode := tm.findStartNode()
+		if firstNode != nil {
+			startNode = firstNode.Key
+		}
+	}
+	if startNode != "" {
+		tm.dfs(startNode, visited, discoveryTime, finishedTime, &timeVal)
+	}
+}
+
+func (tm *DAG) dfs(v string, visited map[string]bool, discoveryTime, finishedTime map[string]int, timeVal *int) {
+	visited[v] = true
+	*timeVal++
+	discoveryTime[v] = *timeVal
+	node := tm.nodes[v]
+	for _, edge := range node.Edges {
+		for _, adj := range edge.To {
+			switch edge.Type {
+			case Simple:
+				if !visited[adj.Key] {
+					fmt.Printf("Simple Edge: %s -> %s\n", v, adj.Key)
+					tm.dfs(adj.Key, visited, discoveryTime, finishedTime, timeVal)
+				}
+			case Iterator:
+				if !visited[adj.Key] {
+					fmt.Printf("Iterator Edge: %s -> %s\n", v, adj.Key)
+					tm.dfs(adj.Key, visited, discoveryTime, finishedTime, timeVal)
+				}
+			}
+
+		}
+	}
+	tm.handleConditionalEdges(v, visited, discoveryTime, finishedTime, timeVal)
+	*timeVal++
+	finishedTime[v] = *timeVal
+}
+
+// handleConditionalEdges processes the conditional edges based on the task result
+func (tm *DAG) handleConditionalEdges(v string, visited map[string]bool, discoveryTime, finishedTime map[string]int, time *int) {
+	node := tm.nodes[v]
+	for when, then := range tm.conditions[FromNode(node.Key)] {
+		if targetNodeKey, ok := tm.nodes[string(then)]; ok {
+			if !visited[targetNodeKey.Key] {
+				fmt.Printf("Conditional Edge [%s]: %s -> %s\n", when, v, targetNodeKey.Key)
+				tm.dfs(targetNodeKey.Key, visited, discoveryTime, finishedTime, time)
+			} else {
+				if discoveryTime[v] > discoveryTime[targetNodeKey.Key] {
+					fmt.Printf("Conditional Loop Edge [%s]: %s -> %s\n", when, v, targetNodeKey.Key)
+				}
+			}
+		}
+	}
+}
+
 func (tm *DAG) onTaskCallback(ctx context.Context, result mq.Result) mq.Result {
 	if taskContext, ok := tm.taskContext[result.TaskID]; ok && result.Topic != "" {
 		return taskContext.handleCallback(ctx, result)
@@ -178,18 +273,18 @@ func (tm *DAG) IsReady() bool {
 	return true
 }
 
-func (tm *DAG) AddCondition(fromNode string, conditions map[When]Then) {
+func (tm *DAG) AddCondition(fromNode FromNode, conditions map[When]Then) {
 	tm.mu.Lock()
 	defer tm.mu.Unlock()
 	tm.conditions[fromNode] = conditions
 }
 
 func (tm *DAG) AddLoop(from string, targets ...string) {
-	tm.addEdge(LoopEdge, from, targets...)
+	tm.addEdge(Iterator, from, targets...)
 }
 
 func (tm *DAG) AddEdge(from string, targets ...string) {
-	tm.addEdge(SimpleEdge, from, targets...)
+	tm.addEdge(Simple, from, targets...)
 }
 
 func (tm *DAG) addEdge(edgeType EdgeType, from string, targets ...string) {
@@ -257,7 +352,7 @@ func (tm *DAG) findStartNode() *Node {
 
 			}
 		}
-		if cond, ok := tm.conditions[node.Key]; ok {
+		if cond, ok := tm.conditions[FromNode(node.Key)]; ok {
 			for _, target := range cond {
 				connectedNodes[string(target)] = true
 				incomingEdges[string(target)] = true

dag/task_manager.go

@@ -82,7 +82,7 @@ func (tm *TaskManager) getConditionalEdges(node *Node, result mq.Result) []Edge
 	edges := make([]Edge, len(node.Edges))
 	copy(edges, node.Edges)
 	if result.Status != "" {
-		if conditions, ok := tm.dag.conditions[result.Topic]; ok {
+		if conditions, ok := tm.dag.conditions[FromNode(result.Topic)]; ok {
 			if targetNodeKey, ok := conditions[When(result.Status)]; ok {
 				if targetNode, ok := tm.dag.nodes[string(targetNodeKey)]; ok {
 					edges = append(edges, Edge{From: node, To: []*Node{targetNode}})
@@ -113,7 +113,7 @@ func (tm *TaskManager) handleCallback(ctx context.Context, result mq.Result) mq.
 	}
 	for _, edge := range edges {
 		switch edge.Type {
-		case LoopEdge:
+		case Iterator:
 			var items []json.RawMessage
 			err := json.Unmarshal(result.Payload, &items)
 			if err != nil {
@@ -126,7 +126,7 @@ func (tm *TaskManager) handleCallback(ctx context.Context, result mq.Result) mq.
 					go tm.processNode(ctx, target, item)
 				}
 			}
-		case SimpleEdge:
+		case Simple:
 			for _, target := range edge.To {
 				ctx = mq.SetHeaders(ctx, map[string]string{consts.QueueKey: target.Key})
 				go tm.processNode(ctx, target, result.Payload)

examples/dag.go

@@ -1,126 +1,104 @@
 package main
 
 import (
+	"context"
+	"encoding/json"
 	"fmt"
-	"sort"
+	"io"
+	"net/http"
+
+	"github.com/oarkflow/mq/consts"
+	"github.com/oarkflow/mq/examples/tasks"
+
+	"github.com/oarkflow/mq"
+	"github.com/oarkflow/mq/dag"
 )
 
-// DAG represents a Directed Acyclic Graph
-type DAG struct {
-	vertices int
-	adjList  map[int][]int // adjacency list to represent edges
-}
+var (
+	d = dag.NewDAG(
+		// mq.WithSyncMode(true),
+		mq.WithNotifyResponse(tasks.NotifyResponse),
+		mq.WithSecretKey([]byte("wKWa6GKdBd0njDKNQoInBbh6P0KTjmob")),
+	)
+	// d = dag.NewDAG(mq.WithSyncMode(true), mq.WithTLS(true, "./certs/server.crt", "./certs/server.key"), mq.WithCAPath("./certs/ca.cert"))
+)
 
-// NewDAG creates a new DAG with a given number of vertices
-func NewDAG(vertices int) *DAG {
-	return &DAG{
-		vertices: vertices,
-		adjList:  make(map[int][]int),
-	}
-}
-
-// AddEdge adds a directed edge from u to v
-func (d *DAG) AddEdge(u, v int) {
-	d.adjList[u] = append(d.adjList[u], v)
-}
-
-// PrintGraph prints the graph's adjacency list
-func (d *DAG) PrintGraph() {
-	for vertex, edges := range d.adjList {
-		fmt.Printf("Vertex %d -> %v\n", vertex, edges)
-	}
-}
-
-// DFS traversal function to classify edges as tree, forward, or cross
-func (d *DAG) ClassifyEdges() {
-	visited := make([]bool, d.vertices)
-	discoveryTime := make([]int, d.vertices)
-	finishedTime := make([]int, d.vertices)
-	time := 0
-
-	for i := 0; i < d.vertices; i++ {
-		if !visited[i] {
-			d.dfs(i, visited, discoveryTime, finishedTime, &time)
-		}
-	}
-}
-
-// dfs performs a DFS and classifies the edges
-func (d *DAG) dfs(v int, visited []bool, discoveryTime []int, finishedTime []int, time *int) {
-	visited[v] = true
-	*time++
-	discoveryTime[v] = *time
-
-	for _, adj := range d.adjList[v] {
-		if !visited[adj] {
-			// Tree Edge: adj not visited, and it's being discovered
-			fmt.Printf("Tree Edge: %d -> %d\n", v, adj)
-			d.dfs(adj, visited, discoveryTime, finishedTime, time)
-		} else {
-			if discoveryTime[v] < discoveryTime[adj] {
-				// Forward Edge: adj is a descendant but already discovered
-				fmt.Printf("Forward Edge: %d -> %d\n", v, adj)
-			} else if finishedTime[adj] == 0 {
-				// Cross Edge: adj is in a different branch (adj was visited, but not fully processed)
-				fmt.Printf("Cross Edge: %d -> %d\n", v, adj)
-			}
-		}
-	}
-
-	*time++
-	finishedTime[v] = *time
-}
-
-// TopologicalSort returns a topologically sorted order of the DAG vertices
-func (d *DAG) TopologicalSort() []int {
-	visited := make([]bool, d.vertices)
-	stack := []int{}
-
-	for i := 0; i < d.vertices; i++ {
-		if !visited[i] {
-			d.topologicalSortUtil(i, visited, &stack)
-		}
-	}
-
-	// Reverse the stack to get the topological order
-	sort.Slice(stack, func(i, j int) bool { return stack[i] > stack[j] })
-	return stack
-}
-
-// Helper function for topological sorting using DFS
-func (d *DAG) topologicalSortUtil(v int, visited []bool, stack *[]int) {
-	visited[v] = true
-
-	for _, adj := range d.adjList[v] {
-		if !visited[adj] {
-			d.topologicalSortUtil(adj, visited, stack)
-		}
-	}
-
-	*stack = append(*stack, v)
-}
-
-// Main function to demonstrate DAG edge classification
 func main() {
-	// Create a new DAG
-	dag := NewDAG(6)
+	d.AddNode("A", "A", tasks.Node1, true)
+	d.AddNode("B", "B", tasks.Node2)
+	d.AddNode("C", "C", tasks.Node3)
+	d.AddNode("D", "D", tasks.Node4)
+	d.AddNode("E", "E", tasks.Node5)
+	d.AddNode("F", "F", tasks.Node6)
+	d.AddNode("G", "G", tasks.Node7)
+	d.AddNode("H", "H", tasks.Node8)
 
-	// Add edges (vertices start from 0)
-	dag.AddEdge(0, 1)
-	dag.AddEdge(0, 2)
-	dag.AddEdge(1, 3)
-	dag.AddEdge(2, 3)
-	dag.AddEdge(3, 4)
-	dag.AddEdge(4, 5)
+	d.AddLoop("A", "B")
+	d.AddCondition("C", map[dag.When]dag.Then{"PASS": "D", "FAIL": "E"})
+	d.AddEdge("B", "C")
+	d.AddEdge("D", "F")
+	d.AddEdge("E", "F")
+	d.AddEdge("F", "G", "H")
 
-	fmt.Println("Graph adjacency list:")
-	dag.PrintGraph()
+	// Classify edges
+	d.ClassifyEdges()
 
-	fmt.Println("\nClassifying edges:")
-	dag.ClassifyEdges()
-
-	// Perform topological sorting
-	fmt.Println("\nTopologically sorted order:")
-	order := dag.TopologicalSort()
-	fmt.Println(order)
+	http.HandleFunc("POST /publish", requestHandler("publish"))
+	http.HandleFunc("POST /request", requestHandler("request"))
+	http.HandleFunc("/pause-consumer/{id}", func(writer http.ResponseWriter, request *http.Request) {
+		id := request.PathValue("id")
+		if id != "" {
+			d.PauseConsumer(request.Context(), id)
+		}
+	})
+	http.HandleFunc("/resume-consumer/{id}", func(writer http.ResponseWriter, request *http.Request) {
+		id := request.PathValue("id")
+		if id != "" {
+			d.ResumeConsumer(request.Context(), id)
+		}
+	})
+	http.HandleFunc("/pause", func(writer http.ResponseWriter, request *http.Request) {
+		d.Pause(true)
+	})
+	http.HandleFunc("/resume", func(writer http.ResponseWriter, request *http.Request) {
+		d.Pause(false)
+	})
+	err := d.Start(context.TODO(), ":8083")
+	if err != nil {
+		panic(err)
+	}
+}
+
+func requestHandler(requestType string) func(w http.ResponseWriter, r *http.Request) {
+	return func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			http.Error(w, "Invalid request method", http.StatusMethodNotAllowed)
+			return
+		}
+		var payload []byte
+		if r.Body != nil {
+			defer r.Body.Close()
+			var err error
+			payload, err = io.ReadAll(r.Body)
+			if err != nil {
+				http.Error(w, "Failed to read request body", http.StatusBadRequest)
+				return
+			}
+		} else {
+			http.Error(w, "Empty request body", http.StatusBadRequest)
+			return
+		}
+		ctx := r.Context()
+		if requestType == "request" {
+			ctx = mq.SetHeaders(ctx, map[string]string{consts.AwaitResponseKey: "true"})
+		}
+		// ctx = context.WithValue(ctx, "initial_node", "E")
+		rs := d.ProcessTask(ctx, payload)
+		if rs.Error != nil {
+			http.Error(w, fmt.Sprintf("[DAG Error] - %v", rs.Error), http.StatusInternalServerError)
+			return
+		}
+		w.Header().Set("Content-Type", "application/json")
+		json.NewEncoder(w).Encode(rs)
+	}
 }