sorted queue

sorted_queue/main.go

@@ -0,0 +1,69 @@
+package queue
+
+import "sync"
+
+type Item struct {
+	ID       string
+	Data     string
+	Priority int
+}
+
+type queue struct {
+	m     map[string]struct{}
+	queue []*Item
+	mu    *sync.Mutex
+}
+
+func NewQueue() *queue {
+	return &queue{
+		m:     map[string]struct{}{},
+		mu:    &sync.Mutex{},
+		queue: []*Item{},
+	}
+}
+
+// put on the queue with no duplicates
+func (q *queue) Put(r *Item) bool {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+
+	_, ok := q.m[r.ID]
+	if ok {
+		return false
+	}
+
+	q.m[r.ID] = struct{}{}
+
+	q.queue = append(q.queue, r)
+
+	if len(q.queue) > 0 {
+		// sort the queue
+		for i := len(q.queue); i > 0; i-- {
+			if q.queue[i].Priority > q.queue[i-1].Priority {
+				q.queue[i] = q.queue[i-1]
+				q.queue[i-1] = q.queue[i]
+			}
+		}
+	}
+
+	return true
+}
+
+func (q *queue) GetNext() *Item {
+	q.mu.Lock()
+	defer q.mu.Unlock()
+
+	if len(q.m) == 0 {
+		return nil
+	}
+
+	r := q.queue[0]
+
+	// delete the id from the map
+	delete(q.m, r.ID)
+
+	// delete from the front of the list
+	q.queue = q.queue[1:]
+
+	return r
+}