Support return query result as a Json string (#2824)

* add toJson() to all datatypes

* add UT for vertex, edge, path

add UT for containers

* add UT for response serialization

* add more UTs

* Fix json format

* Fix UT

* Fix datetime string format in UTC

* Address comments change toJsonObj() to toJson()

src/common/datatypes/DataSet.h

@@ -7,6 +7,8 @@
 #ifndef COMMON_DATATYPES_DATASET_H_
 #define COMMON_DATATYPES_DATASET_H_
 
+#include <folly/dynamic.h>
+
 #include <iostream>
 #include <iterator>
 #include <sstream>
@@ -153,6 +155,44 @@ struct DataSet {
  return os.str();
  }
 
+ // format:
+ // [
+ // {
+ // "row": [ row-data ],
+ // "meta": [ metadata ]
+ // },
+ // ]
+ folly::dynamic toJson() const {
+ // parse rows to json
+ auto dataBody = folly::dynamic::array();
+ for (auto& row : rows) {
+ dataBody.push_back(rowToJson(row));
+ }
+
+ return dataBody;
+ }
+
+ // parse Nebula::Row to json
+ // format:
+ // {
+ // "row": [ row-data ],
+ // "meta": [ metadata ]
+ // }
+ folly::dynamic rowToJson(const Row& row) const {
+ folly::dynamic rowJsonObj = folly::dynamic::object();
+ auto rowDataList = folly::dynamic::array();
+ auto metaDataList = folly::dynamic::array();
+
+ for (const auto& ele : row.values) {
+ rowDataList.push_back(ele.toJson());
+ metaDataList.push_back(ele.getMetaData());
+ }
+
+ rowJsonObj.insert("row", rowDataList);
+ rowJsonObj.insert("meta", metaDataList);
+ return rowJsonObj;
+ }
+
  bool operator==(const DataSet& rhs) const { return colNames == rhs.colNames && rows == rhs.rows; }
 };
 

src/common/datatypes/Date.h

@@ -7,6 +7,8 @@
 #ifndef COMMON_DATATYPES_DATE_H_
 #define COMMON_DATATYPES_DATE_H_
 
+#include <folly/dynamic.h>
+
 #include <string>
 
 namespace nebula {
@@ -62,6 +64,7 @@ struct Date {
  Date operator-(int64_t days) const;
 
  std::string toString() const;
+ folly::dynamic toJson() const { return toString(); }
 
  // Return the number of days since -32768/1/1
  int64_t toInt() const;
@@ -113,6 +116,8 @@ struct Time {
  }
 
  std::string toString() const;
+ // 'Z' representing UTC timezone
+ folly::dynamic toJson() const { return toString() + "Z"; }
 };
 
 inline std::ostream& operator<<(std::ostream& os, const Time& d) {
@@ -203,6 +208,8 @@ struct DateTime {
  }
 
  std::string toString() const;
+ // 'Z' representing UTC timezone
+ folly::dynamic toJson() const { return toString() + "Z"; }
 };
 
 inline std::ostream& operator<<(std::ostream& os, const DateTime& d) {

src/common/datatypes/Edge.cpp

@@ -32,6 +32,45 @@ std::string Edge::toString() const {
  return os.str();
 }
 
+// format:
+// {
+// "prop1": val1,
+// "prop2": val2,
+// }
+folly::dynamic Edge::toJson() const {
+ folly::dynamic propObj = folly::dynamic::object();
+
+ for (const auto& iter : props) {
+ propObj.insert(iter.first, iter.second.toJson());
+ }
+
+ return propObj;
+}
+
+// Used in Json form query result
+// format:
+// {
+// "id": {
+// "name": _name,
+// "src": srcVID,
+// "dst": dstVID,
+// "type": _type,
+// "ranking": _rankding
+// }
+// "type": "edge"
+// }
+folly::dynamic Edge::getMetaData() const {
+ folly::dynamic edgeMetadataObj = folly::dynamic::object();
+
+ folly::dynamic edgeIdObj = folly::dynamic::object("name", name)("src", src.toJson())(
+ "dst", dst.toJson())("type", type)("ranking", ranking);
+
+ edgeMetadataObj.insert("id", edgeIdObj);
+ edgeMetadataObj.insert("type", "edge");
+
+ return edgeMetadataObj;
+}
+
 bool Edge::contains(const Value& key) const {
  if (!key.isStr()) {
  return false;

src/common/datatypes/Edge.h

@@ -50,6 +50,9 @@ struct Edge {
  void __clear() { clear(); }
 
  std::string toString() const;
+ folly::dynamic toJson() const;
+ // Used in Json form query result
+ folly::dynamic getMetaData() const;
 
  bool operator==(const Edge& rhs) const;
 

src/common/datatypes/List.cpp

@@ -22,4 +22,24 @@ std::string List::toString() const {
  return os.str();
 }
 
+folly::dynamic List::toJson() const {
+ auto listJsonObj = folly::dynamic::array();
+
+ for (const auto& val : values) {
+ listJsonObj.push_back(val.toJson());
+ }
+
+ return listJsonObj;
+}
+
+folly::dynamic List::getMetaData() const {
+ auto listMetadataObj = folly::dynamic::array();
+
+ for (const auto& val : values) {
+ listMetadataObj.push_back(val.getMetaData());
+ }
+
+ return listMetadataObj;
+}
+
 } // namespace nebula

src/common/datatypes/List.h

@@ -65,6 +65,9 @@ struct List {
  size_t size() const { return values.size(); }
 
  std::string toString() const;
+ folly::dynamic toJson() const;
+ // Extract the metadata of each element
+ folly::dynamic getMetaData() const;
 };
 
 inline std::ostream& operator<<(std::ostream& os, const List& l) { return os << l.toString(); }

src/common/datatypes/Map.cpp

@@ -14,7 +14,7 @@ namespace nebula {
 
 std::string Map::toString() const {
  std::vector<std::string> value(kvs.size());
- std::transform(kvs.begin(), kvs.end(), value.begin(), [](const auto &iter) -> std::string {
+ std::transform(kvs.begin(), kvs.end(), value.begin(), [](const auto& iter) -> std::string {
  std::stringstream out;
  out << iter.first << ":" << iter.second;
  return out.str();
@@ -25,4 +25,24 @@ std::string Map::toString() const {
  return os.str();
 }
 
+folly::dynamic Map::toJson() const {
+ folly::dynamic mapJsonObj = folly::dynamic::object();
+
+ for (const auto& iter : kvs) {
+ mapJsonObj.insert(iter.first, iter.second.toJson());
+ }
+
+ return mapJsonObj;
+}
+
+folly::dynamic Map::getMetaData() const {
+ auto mapMetadataObj = folly::dynamic::array();
+
+ for (const auto& kv : kvs) {
+ mapMetadataObj.push_back(kv.second.getMetaData());
+ }
+
+ return mapMetadataObj;
+}
+
 } // namespace nebula

src/common/datatypes/Map.h

@@ -43,6 +43,9 @@ struct Map {
  // the configs of rocksdb will use the interface, so the value need modify to
  // string
  std::string toString() const;
+ folly::dynamic toJson() const;
+ // Extract the metadata of the value of each kv pair
+ folly::dynamic getMetaData() const;
 
  bool operator==(const Map& rhs) const { return kvs == rhs.kvs; }
 

src/common/datatypes/Path.h

@@ -130,6 +130,55 @@ struct Path {
  return os.str();
  }
 
+ folly::dynamic toJson() const {
+ folly::dynamic pathJsonObj = folly::dynamic::array();
+ auto srcVertex = src;
+ pathJsonObj.push_back(srcVertex.toJson());
+
+ for (const auto& s : steps) {
+ folly::dynamic edgeJsonObj = folly::dynamic::object();
+ // parse edge props map as json
+ for (const auto& iter : s.props) {
+ edgeJsonObj.insert(iter.first, iter.second.toJson());
+ }
+ // add edge json obj to path
+ pathJsonObj.push_back(edgeJsonObj);
+
+ // reset src vertex and add vertex json obj to path
+ srcVertex = s.dst;
+ pathJsonObj.push_back(srcVertex.toJson());
+ }
+
+ return pathJsonObj;
+ }
+
+ // Used in Json form query result
+ // format:
+ // [vertex1_metadata, edge1_metadata, vertex2_metadata, edge2_metadata,....]
+ folly::dynamic getMetaData() const {
+ auto dynamicObj = folly::dynamic::array();
+ auto srcVertex = src;
+ dynamicObj.push_back(srcVertex.getMetaData());
+
+ // Construct edge metadata
+ for (const auto& s : steps) {
+ folly::dynamic edgeIdObj = folly::dynamic::object();
+ edgeIdObj.insert("src", srcVertex.vid.toJson());
+ edgeIdObj.insert("dst", s.dst.vid.toJson());
+ edgeIdObj.insert("type", s.type);
+ edgeIdObj.insert("name", s.name);
+ edgeIdObj.insert("ranking", s.ranking);
+
+ folly::dynamic edgeMetadataObj = folly::dynamic::object("id", edgeIdObj)("type", "edge");
+ dynamicObj.push_back(edgeMetadataObj);
+ dynamicObj.push_back(s.dst.getMetaData());
+ // reset src vertex
+ srcVertex = s.dst;
+ }
+
+ return dynamicObj;
+ }
+
  Path& operator=(Path&& rhs) noexcept {
  if (&rhs != this) {
  src = std::move(rhs.src);

src/common/datatypes/Set.cpp

@@ -22,4 +22,24 @@ std::string Set::toString() const {
  return os.str();
 }
 
+folly::dynamic Set::toJson() const {
+ auto setJsonObj = folly::dynamic::array();
+
+ for (const auto& val : values) {
+ setJsonObj.push_back(val.toJson());
+ }
+
+ return setJsonObj;
+}
+
+folly::dynamic Set::getMetaData() const {
+ auto setMetadataObj = folly::dynamic::array();
+
+ for (const auto& val : values) {
+ setMetadataObj.push_back(val.getMetaData());
+ }
+
+ return setMetadataObj;
+}
+
 } // namespace nebula

src/common/datatypes/Set.h

@@ -26,6 +26,9 @@ struct Set {
  void __clear() { clear(); }
 
  std::string toString() const;
+ folly::dynamic toJson() const;
+ // Extract the metadata of each element
+ folly::dynamic getMetaData() const;
 
  Set& operator=(const Set& rhs) {
  if (this == &rhs) {