adding iterator interface and removing GetAll() method from attribute list

instrumentation/opentelemetry/span.go

@@ -15,6 +15,27 @@ import (
 	"go.opentelemetry.io/otel/trace"
 )
 
+var _ sdk.Iterator = (*Iterator)(nil)
+
+type Iterator struct {
+	size  int
+	curr  int
+	attrs []attribute.KeyValue
+}
+
+func (i *Iterator) HasNext() bool {
+	return i.curr < i.size
+}
+
+func (i *Iterator) Next() sdk.Attribute {
+	attr := sdk.Attribute{
+		Key:   string(i.attrs[i.curr].Key),
+		Value: i.attrs[i.curr].Value.AsInterface(),
+	}
+	i.curr++
+	return attr
+}
+
 var _ sdk.AttributeList = (*AttributeList)(nil)
 
 type AttributeList struct {
@@ -31,13 +52,12 @@ func (l *AttributeList) GetValue(key string) interface{} {
 	return nil
 }
 
-func (l *AttributeList) GetAll() []sdk.Attribute {
-	size := len(l.attrs)
-	attributes := make([]sdk.Attribute, size)
-	for i := 0; i < size; i++ {
-		attributes[i] = sdk.Attribute{Key: string(l.attrs[i].Key), Value: l.attrs[i].Value.AsInterface()}
+func (l *AttributeList) GetIterator() sdk.Iterator {
+	return &Iterator{
+		size:  len(l.attrs),
+		curr:  0,
+		attrs: l.attrs,
 	}
-	return attributes
 }
 
 var _ sdk.Span = (*Span)(nil)

instrumentation/opentelemetry/span_test.go

@@ -110,7 +110,7 @@ func TestGetAttributes(t *testing.T) {
 	assert.Equal(t, nil, attrs.GetValue("non_existent"))
 }
 
-func TestGetAllAttributes(t *testing.T) {
+func TestGetIterator(t *testing.T) {
 	sampler := sdktrace.AlwaysSample()
 	tp := sdktrace.NewTracerProvider(
 		sdktrace.WithSampler(sampler),
@@ -119,15 +119,18 @@ func TestGetAllAttributes(t *testing.T) {
 	_, s, _ := StartSpan(context.Background(), "test_span", &sdk.SpanOptions{})
 	s.SetAttribute("k1", "v1")
 	s.SetAttribute("k2", 200)
-	attrs := s.GetAttributes().GetAll()
+	itr := s.GetAttributes().GetIterator()
 
-	// service.instance.id is added implicitly in StartSpan so 3 attributes will be present.
-	assert.Equal(t, 3, len(attrs))
-	for _, attr := range attrs {
+	numAttrs := 0
+	for itr.HasNext() {
+		numAttrs++
+		attr := itr.Next()
 		if attr.Key == "k1" {
 			assert.Equal(t, "v1", fmt.Sprintf("%v", attr.Value))
 		} else if attr.Key == "k2" {
 			assert.Equal(t, "200", fmt.Sprintf("%v", attr.Value))
 		}
 	}
+	// service.instance.id is added implicitly in StartSpan so 3 attributes will be present.
+	assert.Equal(t, 3, numAttrs)
 }

sdk/internal/mock/span.go

@@ -19,6 +19,29 @@ type Status struct {
 	Message string
 }
 
+var _ sdk.Iterator = (*Iterator)(nil)
+
+type Iterator struct {
+	size   int
+	curr   int
+	keySet []string
+	attrs  map[string]interface{}
+}
+
+func (i *Iterator) HasNext() bool {
+	return i.curr < i.size
+}
+
+func (i *Iterator) Next() sdk.Attribute {
+	key := i.keySet[i.curr]
+	attr := sdk.Attribute{
+		Key:   key,
+		Value: i.attrs[key],
+	}
+	i.curr++
+	return attr
+}
+
 var _ sdk.AttributeList = (*AttributeList)(nil)
 
 type AttributeList struct {
@@ -29,15 +52,21 @@ func (l *AttributeList) GetValue(key string) interface{} {
 	return l.attrs[key]
 }
 
-func (l *AttributeList) GetAll() []sdk.Attribute {
+func (l *AttributeList) GetIterator() sdk.Iterator {
 
-	attributes := make([]sdk.Attribute, len(l.attrs))
+	keySet := make([]string, len(l.attrs))
 	i := 0
-	for key, value := range l.attrs {
-		attributes[i] = sdk.Attribute{Key: key, Value: value}
+	for k := range l.attrs {
+		keySet[i] = k
 		i++
 	}
-	return attributes
+
+	return &Iterator{
+		size:   len(l.attrs),
+		curr:   0,
+		keySet: keySet,
+		attrs:  l.attrs,
+	}
 }
 
 var _ sdk.Span = &Span{}

sdk/span.go

@@ -10,9 +10,14 @@ type Attribute struct {
 	Value interface{}
 }
 
+type Iterator interface {
+	HasNext() bool
+	Next() Attribute
+}
+
 type AttributeList interface {
 	GetValue(key string) interface{}
-	GetAll() []Attribute
+	GetIterator() Iterator
 }
 
 // Span is an interface that accepts attributes and can be