feat: implement task cancellation feature and update task handling

queue/queue.go

@@ -8,30 +8,58 @@ import (
 )
 
 type TaskQueue struct {
-	list  *list.List
-	cond  *sync.Cond
-	mutex *sync.Mutex
+	list      *list.List
+	cond      *sync.Cond
+	mutex     *sync.Mutex
+	activeMap map[string]*types.Task
 }
 
-func (q *TaskQueue) AddTask(task types.Task) {
+func (q *TaskQueue) AddTask(task *types.Task) {
 	q.mutex.Lock()
 	defer q.mutex.Unlock()
-	q.list.PushBack(task)
-	q.cond.Signal()
+	if task.Status == types.Pending {
+		q.list.PushBack(task)
+		q.cond.Signal()
+	} else {
+		delete(q.activeMap, task.Key())
+	}
 }
 
-func (q *TaskQueue) GetTask() types.Task {
+func (q *TaskQueue) GetTask() *types.Task {
 	q.mutex.Lock()
 	defer q.mutex.Unlock()
 	for q.list.Len() == 0 {
 		q.cond.Wait()
 	}
 	e := q.list.Front()
-	task := e.Value.(types.Task)
+	task := e.Value.(*types.Task)
 	q.list.Remove(e)
+	q.activeMap[task.Key()] = task
 	return task
 }
 
+func (q *TaskQueue) CancelTask(key string) bool {
+	q.mutex.Lock()
+	defer q.mutex.Unlock()
+	if task, ok := q.activeMap[key]; ok {
+		if task.Cancel != nil {
+			task.Cancel()
+			return true
+		}
+	}
+	for e := q.list.Front(); e != nil; e = e.Next() {
+		task := e.Value.(*types.Task)
+		if task.Key() == key {
+			if task.Cancel != nil {
+				task.Cancel()
+			}
+			q.list.Remove(e)
+			return true
+		}
+	}
+	return false
+}
+
 func (q *TaskQueue) Len() int {
 	q.mutex.Lock()
 	defer q.mutex.Unlock()
@@ -47,20 +75,25 @@ func init() {
 func NewQueue() *TaskQueue {
 	m := &sync.Mutex{}
 	return &TaskQueue{
-		list:  list.New(),
-		cond:  sync.NewCond(m),
-		mutex: m,
+		list:      list.New(),
+		cond:      sync.NewCond(m),
+		mutex:     m,
+		activeMap: make(map[string]*types.Task),
 	}
 }
 
-func AddTask(task types.Task) {
+func AddTask(task *types.Task) {
 	Queue.AddTask(task)
 }
 
-func GetTask() types.Task {
+func GetTask() *types.Task {
 	return Queue.GetTask()
 }
 
 func Len() int {
 	return Queue.Len()
 }
+
+func CancelTask(key string) bool {
+	return Queue.CancelTask(key)
+}