sorted queue

sorted_queue/coverage.out

@@ -0,0 +1 @@
+mode: set

sorted_queue/go.mod

@@ -0,0 +1,3 @@
+module github.com/cubixle/playground/sorted_queue
+
+go 1.22.0

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
+}

sorted_queue/main_test.go

@@ -0,0 +1,32 @@
+package queue_test
+
+import (
+	"testing"
+
+	queue "github.com/cubixle/playground/sorted_queue"
+)
+
+func TestQueue(t *testing.T) {
+	q := queue.NewQueue()
+	q.Put(&queue.Item{ID: "aaa", Priority: 6})
+	q.Put(&queue.Item{ID: "bbb", Priority: 7})
+	q.Put(&queue.Item{ID: "ccc", Priority: 2})
+	q.Put(&queue.Item{ID: "ddd", Priority: 1})
+
+	v := q.GetNext()
+	if v == nil {
+		t.Fatal("didn't get a item")
+	}
+	if v.ID != "bbb" {
+		t.Fatal("id wasn't what we expected")
+	}
+	if v.ID != "aaa" {
+		t.Fatal("id wasn't what we expected")
+	}
+	if v.ID != "ccc" {
+		t.Fatal("id wasn't what we expected")
+	}
+	if v.ID != "ddd" {
+		t.Fatal("id wasn't what we expected")
+	}
+}