Merge pull request #1357 from ydb-platform/xsync-set

added `internal/xsync.Map.Delete` + `internal/xsync.Set`

Author: asmyasnikov

internal/xsync/map.go

@@ -42,6 +42,12 @@ func (m *Map[K, V]) Store(key K, value V) {
 	m.m.Store(key, value)
 }
 
+func (m *Map[K, V]) Delete(key K) (ok bool) {
+	_, ok = m.LoadAndDelete(key)
+
+	return ok
+}
+
 func (m *Map[K, V]) LoadAndDelete(key K) (value V, ok bool) {
 	v, ok := m.m.LoadAndDelete(key)
 	if !ok {

internal/xsync/set.go

@@ -0,0 +1,39 @@
+package xsync
+
+import (
+	"sync"
+)
+
+type Set[K comparable] struct {
+	m sync.Map
+}
+
+func (m *Set[K]) Has(key K) bool {
+	_, ok := m.m.Load(key)
+
+	return ok
+}
+
+func (m *Set[K]) Add(key K) bool {
+	_, loaded := m.m.LoadOrStore(key, struct{}{})
+
+	return !loaded
+}
+
+func (m *Set[K]) Remove(key K) (ok bool) {
+	_, ok = m.m.LoadAndDelete(key)
+
+	return ok
+}
+
+func (m *Set[K]) Clear() (removed int) {
+	m.m.Range(func(k, v any) bool {
+		removed++
+
+		m.m.Delete(k)
+
+		return true
+	})
+
+	return removed
+}

internal/xsync/set_test.go

@@ -0,0 +1,19 @@
+package xsync
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestSet(t *testing.T) {
+	var s Set[int]
+	require.False(t, s.Has(1))
+	require.True(t, s.Add(1))
+	require.False(t, s.Add(1))
+	require.True(t, s.Has(1))
+	require.True(t, s.Add(2))
+	require.True(t, s.Remove(1))
+	require.False(t, s.Has(1))
+	require.Equal(t, 1, s.Clear())
+}