InfluxDB: Add support for LIST arrow type (#93227)

Add support for LIST arrow type

pkg/tsdb/influxdb/fsql/arrow.go

@@ -151,6 +151,9 @@ func newField(f arrow.Field) *data.Field {
 		return newDataField[time.Time](f)
 	case arrow.DURATION:
 		return newDataField[int64](f)
+	case arrow.LIST:
+		nestedType := f.Type.(*arrow.ListType).ElemField()
+		return newField(nestedType)
 	default:
 		return newDataField[json.RawMessage](f)
 	}
@@ -166,6 +169,8 @@ func newDataField[T any](f arrow.Field) *data.Field {
 }
 
 // copyData copies the contents of an Arrow column into a Data Frame field.
+//
+//nolint:gocyclo
 func copyData(field *data.Field, col arrow.Array) error {
 	defer func() {
 		if r := recover(); r != nil {
@@ -174,7 +179,6 @@ func copyData(field *data.Field, col arrow.Array) error {
 	}()
 
 	colData := col.Data()
-
 	switch col.DataType().ID() {
 	case arrow.TIMESTAMP:
 		v := array.NewTimestampData(colData)
@@ -221,6 +225,19 @@ func copyData(field *data.Field, col arrow.Array) error {
 			}
 			field.Append(json.RawMessage(b))
 		}
+	case arrow.LIST:
+		v := array.NewListData(colData)
+		for i := 0; i < v.Len(); i++ {
+			sc, err := scalar.GetScalar(v, i)
+			if err != nil {
+				return err
+			}
+
+			err = copyData(field, sc.(*scalar.List).Value)
+			if err != nil {
+				return err
+			}
+		}
 	case arrow.STRING:
 		copyBasic[string](field, array.NewStringData(colData))
 	case arrow.UINT8:

pkg/tsdb/influxdb/fsql/arrow_test.go

@@ -37,6 +37,8 @@ func TestNewQueryDataResponse(t *testing.T) {
 			{Name: "utf8", Type: &arrow.StringType{}},
 			{Name: "duration", Type: &arrow.DurationType{}},
 			{Name: "timestamp", Type: &arrow.TimestampType{}},
+
+			{Name: "item", Type: arrow.ListOf(&arrow.StringType{})},
 		},
 		nil,
 	)
@@ -58,6 +60,8 @@ func TestNewQueryDataResponse(t *testing.T) {
 		newJSONArray(`["foo", "bar", "baz"]`, &arrow.StringType{}),
 		newJSONArray(`[0, 1, -2]`, &arrow.DurationType{}),
 		newJSONArray(`[0, 1, 2]`, &arrow.TimestampType{}),
+
+		newJSONArray(`[["test", "test1", "test2"],[],[]]`, arrow.ListOf(&arrow.StringType{})),
 	}
 
 	arr := make([]arrow.Array, 0, len(strValues))
@@ -82,7 +86,7 @@ func TestNewQueryDataResponse(t *testing.T) {
 	resp := newQueryDataResponse(errReader{RecordReader: reader}, query, metadata.MD{})
 	assert.NoError(t, resp.Error)
 	assert.Len(t, resp.Frames, 1)
-	assert.Len(t, resp.Frames[0].Fields, 13)
+	assert.Len(t, resp.Frames[0].Fields, 14)
 
 	frame := resp.Frames[0]
 	f0 := frame.Fields[0]
@@ -156,6 +160,14 @@ func TestNewQueryDataResponse(t *testing.T) {
 		},
 		extractFieldValues[time.Time](t, f12),
 	)
+
+	s1 := "test"
+	s2 := "test1"
+	s3 := "test2"
+	f13 := frame.Fields[13]
+	assert.Equal(t, f13.Name, "item")
+	assert.Equal(t, f13.Type(), data.FieldTypeNullableString)
+	assert.Equal(t, []*string{&s1, &s2, &s3}, extractFieldValues[*string](t, f13))
 }
 
 type jsonArray struct {