Merge pull request #1631 from ydb-platform/xsync-slice

added `xsync.Slice`

Author: asmyasnikov

internal/xsync/slice.go

@@ -0,0 +1,62 @@
+package xsync
+
+import (
+	"sync"
+)
+
+type Slice[T any] struct {
+	m sync.RWMutex
+	s []T
+}
+
+func (s *Slice[T]) Append(v T) {
+	s.m.Lock()
+	defer s.m.Unlock()
+
+	s.s = append(s.s, v)
+}
+
+func (s *Slice[T]) Size() int {
+	s.m.RLock()
+	defer s.m.RUnlock()
+
+	return len(s.s)
+}
+
+func (s *Slice[T]) Range(f func(idx int, v T) bool) {
+	s.m.RLock()
+	defer s.m.RUnlock()
+
+	for idx, v := range s.s {
+		if !f(idx, v) {
+			break
+		}
+	}
+}
+
+func (s *Slice[T]) Remove(idx int) bool {
+	s.m.Lock()
+	defer s.m.Unlock()
+
+	if idx >= len(s.s) {
+		return false
+	}
+
+	s.s = append(s.s[:idx], s.s[idx+1:]...)
+
+	return true
+}
+
+func (s *Slice[T]) Clear() (removed int) {
+	s.m.Lock()
+	defer s.m.Unlock()
+
+	if s.s == nil {
+		return 0
+	}
+
+	l := len(s.s)
+	s.s = s.s[:0]
+
+	return l
+}

internal/xsync/slice_test.go

@@ -0,0 +1,32 @@
+package xsync
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestSlice(t *testing.T) {
+	var s Slice[int]
+	require.Equal(t, 0, s.Size())
+	require.Equal(t, 0, s.Clear())
+	s.Append(1)
+	require.Equal(t, 1, s.Size())
+	s.Range(func(idx int, v int) bool {
+		require.Equal(t, 0, idx)
+		require.Equal(t, 1, v)
+
+		return true
+	})
+	require.False(t, s.Remove(1))
+	s.Append(2)
+	var rangeFuncCounter int
+	s.Range(func(idx int, v int) bool {
+		rangeFuncCounter++
+
+		return false
+	})
+	require.Equal(t, 1, rangeFuncCounter)
+	require.True(t, s.Remove(1))
+	require.Equal(t, 1, s.Clear())
+}