[#352] container: Implement iterators over attributes

Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

container/container.go

@@ -5,6 +5,7 @@ import (
 	"crypto/sha256"
 	"errors"
 	"fmt"
+	"iter"
 	"strconv"
 	"strings"
 	"time"
@@ -337,10 +338,41 @@ func (x Container) Attribute(key string) string {
 	return ""
 }
 
+// Attributes returns an iterator over all Container attributes.
+//
+// See also [Container.SetAttribute], [Container.UserAttributes].
+func (x Container) Attributes() iter.Seq2[string, string] {
+	return func(yield func(string, string) bool) {
+		attrs := x.v2.GetAttributes()
+		for i := range attrs {
+			if !yield(attrs[i].GetKey(), attrs[i].GetValue()) {
+				return
+			}
+		}
+	}
+}
+
+// Attributes returns an iterator over all non-system Container attributes.
+//
+// See also [Container.SetAttribute], [Container.Attributes].
+func (x Container) UserAttributes() iter.Seq2[string, string] {
+	return func(yield func(string, string) bool) {
+		for key, value := range x.Attributes() {
+			if !strings.HasPrefix(key, container.SysAttributePrefix) {
+				if !yield(key, value) {
+					return
+				}
+			}
+		}
+	}
+}
+
 // IterateAttributes iterates over all Container attributes and passes them
 // into f. The handler MUST NOT be nil.
 //
 // See also SetAttribute, Attribute.
+//
+// Deprecated: use [Container.Attributes] instead.
 func (x Container) IterateAttributes(f func(key, val string)) {
 	attrs := x.v2.GetAttributes()
 	for i := range attrs {
@@ -352,6 +384,8 @@ func (x Container) IterateAttributes(f func(key, val string)) {
 // into f. The handler MUST NOT be nil.
 //
 // See also SetAttribute, Attribute.
+//
+// Deprecated: use [Container.UserAttributes] instead.
 func (x Container) IterateUserAttributes(f func(key, val string)) {
 	attrs := x.v2.GetAttributes()
 	for _, attr := range attrs {

container/container_test.go

@@ -2,6 +2,7 @@ package container_test
 
 import (
 	"crypto/sha256"
+	"maps"
 	"strconv"
 	"testing"
 	"time"
@@ -159,9 +160,9 @@ func TestContainer_Attribute(t *testing.T) {
 	val.SetAttribute(attrKey2, attrVal2)
 
 	var i int
-	val.IterateUserAttributes(func(key, val string) {
+	for range val.UserAttributes() {
 		i++
-	})
+	}
 	require.Equal(t, 1, i)
 
 	var msg v2container.Container
@@ -177,11 +178,7 @@ func TestContainer_Attribute(t *testing.T) {
 	require.Equal(t, attrVal1, val2.Attribute(attrKey1))
 	require.Equal(t, attrVal2, val2.Attribute(attrKey2))
 
-	m := map[string]string{}
-
-	val2.IterateAttributes(func(key, val string) {
-		m[key] = val
-	})
+	m := maps.Collect(val2.Attributes())
 
 	require.GreaterOrEqual(t, len(m), 2)
 	require.Equal(t, attrVal1, m[attrKey1])

container/iterators_test.go

@@ -0,0 +1,95 @@
+package container_test
+
+import (
+	"testing"
+
+	containerAPI "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/api/container"
+	"git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container"
+	"github.com/stretchr/testify/require"
+)
+
+func TestContainer_Attributes(t *testing.T) {
+	t.Run("empty", func(t *testing.T) {
+		var n container.Container
+		t.Run("attributes", func(t *testing.T) {
+			for range n.Attributes() {
+				t.Fatalf("handler is called, but it shouldn't")
+			}
+		})
+		t.Run("user attributes", func(t *testing.T) {
+			for range n.UserAttributes() {
+				t.Fatalf("handler is called, but it shouldn't")
+			}
+		})
+	})
+
+	var n container.Container
+	n.SetAttribute(containerAPI.SysAttributeName, "myname")
+	n.SetAttribute("key1", "value1")
+	n.SetAttribute("key2", "value2")
+	n.SetAttribute(containerAPI.SysAttributeZone, "test")
+
+	t.Run("break", func(t *testing.T) {
+		t.Run("attributes", func(t *testing.T) {
+			var res [][2]string
+			for key, value := range n.Attributes() {
+				if key == "key2" {
+					break
+				}
+				res = append(res, [2]string{key, value})
+			}
+			require.Equal(t, [][2]string{{containerAPI.SysAttributeName, "myname"}, {"key1", "value1"}}, res)
+		})
+		t.Run("user attributes", func(t *testing.T) {
+			var res [][2]string
+			for key, value := range n.UserAttributes() {
+				if key == "key2" {
+					break
+				}
+				res = append(res, [2]string{key, value})
+			}
+			require.Equal(t, [][2]string{{"key1", "value1"}}, res)
+		})
+	})
+	t.Run("continue", func(t *testing.T) {
+		t.Run("attributes", func(t *testing.T) {
+			var res [][2]string
+			for key, value := range n.Attributes() {
+				if key == "key2" {
+					continue
+				}
+				res = append(res, [2]string{key, value})
+			}
+			require.Equal(t, [][2]string{{containerAPI.SysAttributeName, "myname"}, {"key1", "value1"}, {containerAPI.SysAttributeZone, "test"}}, res)
+		})
+		t.Run("user attributes", func(t *testing.T) {
+			var res [][2]string
+			for key, value := range n.UserAttributes() {
+				if key == "key2" {
+					continue
+				}
+				res = append(res, [2]string{key, value})
+			}
+			require.Equal(t, [][2]string{{"key1", "value1"}}, res)
+		})
+	})
+	t.Run("attributes", func(t *testing.T) {
+		var res [][2]string
+		for key, value := range n.Attributes() {
+			res = append(res, [2]string{key, value})
+		}
+		require.Equal(t, [][2]string{
+			{containerAPI.SysAttributeName, "myname"},
+			{"key1", "value1"},
+			{"key2", "value2"},
+			{containerAPI.SysAttributeZone, "test"},
+		}, res)
+	})
+	t.Run("user attributes", func(t *testing.T) {
+		var res [][2]string
+		for key, value := range n.UserAttributes() {
+			res = append(res, [2]string{key, value})
+		}
+		require.Equal(t, [][2]string{{"key1", "value1"}, {"key2", "value2"}}, res)
+	})
+}