Rework project's structure

internal/utils/queue.go

@@ -0,0 +1,40 @@
+package utils
+
+import (
+	"sync"
+)
+
+type Queue[T any] struct {
+	lock  sync.Mutex
+	items []T
+}
+
+func NewQueue[T any]() *Queue[T] {
+	return &Queue[T]{
+		items: []T{},
+	}
+}
+
+func (s *Queue[T]) Enqueue(item T) int {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	s.items = append(s.items, item)
+
+	return len(s.items)
+}
+
+func (s *Queue[T]) Dequeue(n int) ([]T, int) {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	l := len(s.items)
+	if n > l {
+		n = l
+	}
+
+	items := s.items[0:n]
+	s.items = s.items[n:l]
+
+	return items, l - n
+}

internal/utils/queue_test.go

@@ -0,0 +1,38 @@
+package utils
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestQueue(t *testing.T) {
+	t.Run("Enqueue", func(t *testing.T) {
+		s := NewQueue[string]()
+		require.Equal(t, 1, s.Enqueue("username1"))
+		require.Equal(t, 2, s.Enqueue("username2"))
+		require.Equal(t, 3, s.Enqueue("username3"))
+	})
+
+	t.Run("Dequeue", func(t *testing.T) {
+		s := NewQueue[string]()
+		s.Enqueue("username1")
+		s.Enqueue("username2")
+		s.Enqueue("username3")
+		s.Enqueue("username4")
+		s.Enqueue("username5")
+
+		items, queueLen := s.Dequeue(2)
+		require.Len(t, items, 2)
+		require.Equal(t, 3, queueLen)
+		require.Equal(t, "username1", items[0])
+		require.Equal(t, "username2", items[1])
+
+		items, queueLen = s.Dequeue(40)
+		require.Len(t, items, 3)
+		require.Equal(t, 0, queueLen)
+		require.Equal(t, "username3", items[0])
+		require.Equal(t, "username4", items[1])
+		require.Equal(t, "username5", items[2])
+	})
+}

internal/utils/time.go

@@ -0,0 +1,7 @@
+package utils
+
+import "time"
+
+func UnixMillisecond(t time.Time) int64 {
+	return t.UnixNano() / int64(time.Millisecond)
+}

internal/utils/time_test.go

@@ -0,0 +1,16 @@
+package utils
+
+import (
+	"time"
+
+	"testing"
+
+	assert "github.com/stretchr/testify/require"
+)
+
+func TestUnixMillisecond(t *testing.T) {
+	loc, _ := time.LoadLocation("CET")
+	d := time.Date(2021, 02, 26, 00, 43, 57, 987654321, loc)
+
+	assert.Equal(t, int64(1614296637987), UnixMillisecond(d))
+}