add metadata to query request/response (#1215)

Author: dmitsh

state/azure/cosmosdb/cosmosdb_query.go

@@ -128,7 +128,7 @@ func (q *Query) setNextParameter(val string) string {
 	return pname
 }
 
-func (q *Query) execute(client *documentdb.DocumentDB, collection *documentdb.Collection) ([]state.QueryResult, string, error) {
+func (q *Query) execute(client *documentdb.DocumentDB, collection *documentdb.Collection) ([]state.QueryItem, string, error) {
 	opts := []documentdb.CallOption{documentdb.CrossPartition()}
 	if q.limit != 0 {
 		opts = append(opts, documentdb.Limit(q.limit))
@@ -143,7 +143,7 @@ func (q *Query) execute(client *documentdb.DocumentDB, collection *documentdb.Co
 	}
 	token := resp.Header.Get(documentdb.HeaderContinuation)
 
-	ret := make([]state.QueryResult, len(items))
+	ret := make([]state.QueryItem, len(items))
 	for i := range items {
 		ret[i].Key = items[i].ID
 		ret[i].ETag = ptr.String(items[i].Etag)

state/mongodb/mongodb_query.go

@@ -128,19 +128,19 @@ func (q *Query) Finalize(filters string, qq *query.Query) error {
 	return nil
 }
 
-func (q *Query) execute(ctx context.Context, collection *mongo.Collection) ([]state.QueryResult, string, error) {
+func (q *Query) execute(ctx context.Context, collection *mongo.Collection) ([]state.QueryItem, string, error) {
 	cur, err := collection.Find(ctx, q.filter, []*options.FindOptions{q.opts}...)
 	if err != nil {
 		return nil, "", err
 	}
 	defer cur.Close(ctx)
-	ret := []state.QueryResult{}
+	ret := []state.QueryItem{}
 	for cur.Next(ctx) {
 		var item Item
 		if err = cur.Decode(&item); err != nil {
 			return nil, "", err
 		}
-		result := state.QueryResult{
+		result := state.QueryItem{
 			Key:  item.Key,
 			ETag: &item.Etag,
 		}

state/requests.go

@@ -97,5 +97,6 @@ type KeyInt interface {
 }
 
 type QueryRequest struct {
-	Query query.Query `json:"query"`
+	Query    query.Query       `json:"query"`
+	Metadata map[string]string `json:"metadata,omitempty"`
 }

state/responses.go

@@ -23,12 +23,13 @@ type BulkGetResponse struct {
 
 // QueryResponse is the response object for querying state.
 type QueryResponse struct {
-	Results []QueryResult `json:"results"`
-	Token   string        `json:"token,omitempty"`
+	Results  []QueryItem       `json:"results"`
+	Token    string            `json:"token,omitempty"`
+	Metadata map[string]string `json:"metadata,omitempty"`
 }
 
-// QueryResult is an object representing a single entry in query result.
-type QueryResult struct {
+// QueryItem is an object representing a single entry in query results.
+type QueryItem struct {
 	Key   string  `json:"key"`
 	Data  []byte  `json:"data"`
 	ETag  *string `json:"etag,omitempty"`

tests/conformance/state/state.go

@@ -35,7 +35,7 @@ type scenario struct {
 
 type queryScenario struct {
 	query   string
-	results []state.QueryResult
+	results []state.QueryItem
 }
 
 type TestConfig struct {
@@ -213,7 +213,7 @@ func ConformanceTests(t *testing.T, props map[string]string, statestore state.St
 				}
 			}
 			`,
-			results: []state.QueryResult{
+			results: []state.QueryItem{
 				{
 					Key:  fmt.Sprintf("%s-struct", key),
 					Data: []byte(fmt.Sprintf("{\"message\":\"%s-test\"}", key)),