extend GraphPersistenceStrategy to expose IdAttrName and materialization of internal Id StructType

repository/src/main/java/org/apache/hadoop/metadata/discovery/graph/DefaultGraphPersistenceStrategy.java

@@ -108,8 +108,17 @@ public class DefaultGraphPersistenceStrategy implements GraphPersistenceStrategi
                     TitanVertex structVertex = (TitanVertex) value;
                     StructType structType = (StructType) dataType;
                     ITypedStruct structInstance = structType.createInstance();
-                    metadataRepository.getGraphToInstanceMapper().mapVertexToInstance(
-                            structVertex, structInstance, structType.fieldMapping().fields);
+
+                    if ( dataType.getName() == TypeUtils.INSTANCE_ID_TYP().getName()) {
+                        structInstance.set(TypeUtils.INSTANCE_ID_TYP_TYPENAME_ATTRNAME(),
+                                structVertex.getProperty(typeAttributeName()));
+                        structInstance.set(TypeUtils.INSTANCE_ID_TYP_ID_ATTRNAME(),
+                                structVertex.getProperty(idAttributeName()));
+
+                    } else {
+                        metadataRepository.getGraphToInstanceMapper().mapVertexToInstance(
+                                structVertex, structInstance, structType.fieldMapping().fields);
+                    }
                     return dataType.convert(structInstance, Multiplicity.OPTIONAL);
 
                 case TRAIT:
@@ -180,4 +189,14 @@ public class DefaultGraphPersistenceStrategy implements GraphPersistenceStrategi
     public String loopObjectExpression(IDataType<?> dataType) {
         return "{it.object." + typeAttributeName() + " == '" + dataType.getName() + "'}";
     }
+
+    @Override
+    public String instanceToTraitEdgeDirection() { return "out"; }
+
+    @Override
+    public String traitToInstanceEdgeDirection() { return "in"; }
+
+    @Override
+    public String idAttributeName() { return metadataRepository.getIdAttributeName(); }
+
 }

repository/src/main/java/org/apache/hadoop/metadata/repository/graph/GraphBackedMetadataRepository.java

@@ -96,6 +96,10 @@ public class GraphBackedMetadataRepository implements MetadataRepository {
         return Constants.ENTITY_TYPE_PROPERTY_KEY;
     }
 
+    public String getIdAttributeName() {
+        return Constants.GUID_PROPERTY_KEY;
+    }
+
     @Override
     public String getTraitLabel(IDataType<?> dataType, String traitName) {
         return dataType.getName() + "." + traitName;

repository/src/main/scala/org/apache/hadoop/metadata/query/GraphPersistenceStrategies.scala

@@ -45,12 +45,24 @@ trait GraphPersistenceStrategies {
     def typeAttributeName: String
 
     /**
+     * Name of attribute used to store guid in vertex
+     */
+    def idAttributeName : String
+
+    /**
      * Given a dataType and a reference attribute, how is edge labeled
      */
     def edgeLabel(iDataType: IDataType[_], aInfo: AttributeInfo): String
 
     def traitLabel(cls: IDataType[_], traitName: String): String
 
+    def instanceToTraitEdgeDirection : String = "out"
+    def traitToInstanceEdgeDirection = instanceToTraitEdgeDirection match {
+      case "out" => "in"
+      case "in" => "out"
+      case x => x
+    }
+
     /**
      * The propertyKey used to store the attribute in a Graph Vertex.
      * @param dataType
@@ -101,6 +113,7 @@ trait GraphPersistenceStrategies {
 
 object GraphPersistenceStrategy1 extends GraphPersistenceStrategies {
     val typeAttributeName = "typeName"
+    val idAttributeName = "guid"
 
     def edgeLabel(dataType: IDataType[_], aInfo: AttributeInfo) = s"${dataType.getName}.${aInfo.name}"
 
@@ -125,6 +138,16 @@ object GraphPersistenceStrategy1 extends GraphPersistenceStrategies {
     def constructInstance[U](dataType: IDataType[U], v: AnyRef): U = {
         dataType.getTypeCategory match {
             case DataTypes.TypeCategory.PRIMITIVE => dataType.convert(v, Multiplicity.OPTIONAL)
+            case DataTypes.TypeCategory.STRUCT if dataType.getName == TypeUtils.INSTANCE_ID_TYP.getName => {
+              val sType = dataType.asInstanceOf[StructType]
+              val sInstance = sType.createInstance()
+              val tV = v.asInstanceOf[TitanVertex]
+              sInstance.set(TypeUtils.INSTANCE_ID_TYP_TYPENAME_ATTRNAME,
+                tV.getProperty[java.lang.String](typeAttributeName))
+              sInstance.set(TypeUtils.INSTANCE_ID_TYP_ID_ATTRNAME,
+                tV.getProperty[java.lang.String](idAttributeName))
+              dataType.convert(sInstance, Multiplicity.OPTIONAL)
+            }
             case DataTypes.TypeCategory.STRUCT => {
                 val sType = dataType.asInstanceOf[StructType]
                 val sInstance = sType.createInstance()

repository/src/main/scala/org/apache/hadoop/metadata/query/TypeUtils.scala

@@ -65,6 +65,18 @@ object TypeUtils {
             aDefs:_*);
     }
 
+    val INSTANCE_ID_TYP_ID_ATTRNAME = "guid"
+    val INSTANCE_ID_TYP_TYPENAME_ATTRNAME = "typeName"
+    val INSTANCE_ID_TYP_NAME = TEMP_STRUCT_NAME_PREFIX + "_IdType"
+    val INSTANCE_ID_TYP = {
+      val idAttr = new AttributeDefinition(INSTANCE_ID_TYP_ID_ATTRNAME,
+        DataTypes.STRING_TYPE.getName, Multiplicity.REQUIRED, false, null)
+      val typNmAttr =
+        new AttributeDefinition(INSTANCE_ID_TYP_TYPENAME_ATTRNAME,
+          DataTypes.STRING_TYPE.getName, Multiplicity.REQUIRED, false, null)
+      typSystem.defineQueryResultType(INSTANCE_ID_TYP_NAME, idAttr, typNmAttr);
+    }
+
     def fieldMapping(iDataType: IDataType[_]) : Option[FieldMapping] = iDataType match {
         case c : ClassType => Some(c.fieldMapping())
         case t : TraitType => Some(t.fieldMapping())