/**
   * Adds a new trait to an existing entity represented by a guid.
   *
   * @param guid globally unique identifier for the entity
   * @param traitInstance trait instance that needs to be added to entity
   * @throws RepositoryException
   */
  @Override
  @GraphTransaction
  public void addTrait(String guid, ITypedStruct traitInstance) throws RepositoryException {
    Preconditions.checkNotNull(traitInstance, "Trait instance cannot be null");
    final String traitName = traitInstance.getTypeName();
    LOG.debug("Adding a new trait={} for entity={}", traitName, guid);

    try {
      Vertex instanceVertex = graphHelper.getVertexForGUID(guid);

      // add the trait instance as a new vertex
      final String typeName = GraphHelper.getTypeName(instanceVertex);

      TypedInstanceToGraphMapper instanceToGraphMapper =
          new TypedInstanceToGraphMapper(graphToInstanceMapper, deleteHandler);
      instanceToGraphMapper.mapTraitInstanceToVertex(
          traitInstance, typeSystem.getDataType(ClassType.class, typeName), instanceVertex);

      // update the traits in entity once adding trait instance is successful
      GraphHelper.addProperty(instanceVertex, Constants.TRAIT_NAMES_PROPERTY_KEY, traitName);
      GraphHelper.setProperty(
          instanceVertex,
          Constants.MODIFICATION_TIMESTAMP_PROPERTY_KEY,
          RequestContext.get().getRequestTime());

    } catch (RepositoryException e) {
      throw e;
    } catch (Exception e) {
      throw new RepositoryException(e);
    }
  }
 private void verifyRestoredClassType(TypesDef types, String typeName) throws AtlasException {
   boolean clsTypeFound = false;
   List<HierarchicalTypeDefinition<ClassType>> classTypes = types.classTypesAsJavaList();
   for (HierarchicalTypeDefinition<ClassType> classType : classTypes) {
     if (classType.typeName.equals(typeName)) {
       ClassType expectedType = ts.getDataType(ClassType.class, classType.typeName);
       Assert.assertEquals(
           expectedType.immediateAttrs.size(), classType.attributeDefinitions.length);
       Assert.assertEquals(expectedType.superTypes.size(), classType.superTypes.size());
       Assert.assertEquals(classType.typeDescription, classType.typeName + DESCRIPTION);
       clsTypeFound = true;
     }
   }
   Assert.assertTrue(clsTypeFound, typeName + " type not restored");
 }
  @Test(dependsOnMethods = "testStore")
  public void testRestore() throws Exception {
    TypesDef types = typeStore.restore();

    // validate enum
    List<EnumTypeDefinition> enumTypes = types.enumTypesAsJavaList();
    Assert.assertEquals(1, enumTypes.size());
    EnumTypeDefinition orgLevel = enumTypes.get(0);
    Assert.assertEquals(orgLevel.name, "OrgLevel");
    Assert.assertEquals(orgLevel.description, "OrgLevel" + DESCRIPTION);
    Assert.assertEquals(orgLevel.enumValues.length, 2);
    EnumValue enumValue = orgLevel.enumValues[0];
    Assert.assertEquals(enumValue.value, "L1");
    Assert.assertEquals(enumValue.ordinal, 1);

    // validate class
    List<StructTypeDefinition> structTypes = types.structTypesAsJavaList();
    Assert.assertEquals(1, structTypes.size());

    verifyRestoredClassType(types, "Manager");

    // validate trait
    List<HierarchicalTypeDefinition<TraitType>> traitTypes = types.traitTypesAsJavaList();
    Assert.assertEquals(1, traitTypes.size());
    HierarchicalTypeDefinition<TraitType> trait = traitTypes.get(0);
    Assert.assertEquals("SecurityClearance", trait.typeName);
    Assert.assertEquals(trait.typeName + DESCRIPTION, trait.typeDescription);
    Assert.assertEquals(1, trait.attributeDefinitions.length);
    AttributeDefinition attribute = trait.attributeDefinitions[0];
    Assert.assertEquals("level", attribute.name);
    Assert.assertEquals(DataTypes.INT_TYPE.getName(), attribute.dataTypeName);

    // validate the new types
    ts.reset();
    ts.defineTypes(types);
  }
  @Override
  @GraphTransaction
  public ITypedReferenceableInstance getEntityDefinition(
      String entityType, String attribute, Object value) throws AtlasException {
    LOG.debug("Retrieving entity with type={} and {}={}", entityType, attribute, value);
    IDataType type = typeSystem.getDataType(IDataType.class, entityType);
    String propertyKey = getFieldNameInVertex(type, attribute);
    Vertex instanceVertex =
        graphHelper.findVertex(
            propertyKey,
            value,
            Constants.ENTITY_TYPE_PROPERTY_KEY,
            entityType,
            Constants.STATE_PROPERTY_KEY,
            Id.EntityState.ACTIVE.name());

    String guid = instanceVertex.getProperty(Constants.GUID_PROPERTY_KEY);
    return graphToInstanceMapper.mapGraphToTypedInstance(guid, instanceVertex);
  }
Ejemplo n.º 5
0
/** Utility class for graph operations. */
public final class GraphHelper {

  private static final Logger LOG = LoggerFactory.getLogger(GraphHelper.class);
  public static final String EDGE_LABEL_PREFIX = "__";

  private static final TypeSystem typeSystem = TypeSystem.getInstance();

  private static final GraphHelper INSTANCE =
      new GraphHelper(TitanGraphProvider.getGraphInstance());

  private TitanGraph titanGraph;

  private GraphHelper(TitanGraph titanGraph) {
    this.titanGraph = titanGraph;
  }

  public static GraphHelper getInstance() {
    return INSTANCE;
  }

  public Vertex createVertexWithIdentity(
      ITypedReferenceableInstance typedInstance, Set<String> superTypeNames) {
    final Vertex vertexWithIdentity =
        createVertexWithoutIdentity(
            typedInstance.getTypeName(), typedInstance.getId(), superTypeNames);

    // add identity
    final String guid = UUID.randomUUID().toString();
    setProperty(vertexWithIdentity, Constants.GUID_PROPERTY_KEY, guid);

    // add version information
    setProperty(vertexWithIdentity, Constants.VERSION_PROPERTY_KEY, typedInstance.getId().version);

    return vertexWithIdentity;
  }

  public Vertex createVertexWithoutIdentity(
      String typeName, Id typedInstanceId, Set<String> superTypeNames) {
    LOG.debug(
        "Creating vertex for type {} id {}",
        typeName,
        typedInstanceId != null ? typedInstanceId._getId() : null);
    final Vertex vertexWithoutIdentity = titanGraph.addVertex(null);

    // add type information
    setProperty(vertexWithoutIdentity, Constants.ENTITY_TYPE_PROPERTY_KEY, typeName);

    // add super types
    for (String superTypeName : superTypeNames) {
      addProperty(vertexWithoutIdentity, Constants.SUPER_TYPES_PROPERTY_KEY, superTypeName);
    }

    // add timestamp information
    setProperty(
        vertexWithoutIdentity, Constants.TIMESTAMP_PROPERTY_KEY, System.currentTimeMillis());

    return vertexWithoutIdentity;
  }

  public Edge addEdge(Vertex fromVertex, Vertex toVertex, String edgeLabel) {
    LOG.debug("Adding edge for {} -> label {} -> {}", fromVertex, edgeLabel, toVertex);

    return titanGraph.addEdge(null, fromVertex, toVertex, edgeLabel);
  }

  public Vertex findVertex(String propertyKey, Object value) {
    LOG.debug("Finding vertex for {}={}", propertyKey, value);

    GraphQuery query = titanGraph.query().has(propertyKey, value);
    Iterator<Vertex> results = query.vertices().iterator();
    // returning one since entityType, qualifiedName should be unique
    return results.hasNext() ? results.next() : null;
  }

  public static Iterable<Edge> getOutGoingEdgesByLabel(Vertex instanceVertex, String edgeLabel) {
    if (instanceVertex != null && edgeLabel != null) {
      return instanceVertex.getEdges(Direction.OUT, edgeLabel);
    }
    return null;
  }

  public Edge getOutGoingEdgeById(String edgeId) {
    if (edgeId != null) {
      return titanGraph.getEdge(edgeId);
    }
    return null;
  }

  public static String vertexString(final Vertex vertex) {
    StringBuilder properties = new StringBuilder();
    for (String propertyKey : vertex.getPropertyKeys()) {
      properties
          .append(propertyKey)
          .append("=")
          .append(vertex.getProperty(propertyKey).toString())
          .append(", ");
    }

    return "v[" + vertex.getId() + "], Properties[" + properties + "]";
  }

  public static String edgeString(final Edge edge) {
    return "e["
        + edge.getLabel()
        + "], ["
        + edge.getVertex(Direction.OUT)
        + " -> "
        + edge.getLabel()
        + " -> "
        + edge.getVertex(Direction.IN)
        + "]";
  }

  public static void setProperty(Vertex vertex, String propertyName, Object value) {
    LOG.debug("Setting property {} = \"{}\" to vertex {}", propertyName, value, vertex);
    Object existValue = vertex.getProperty(propertyName);
    if (value == null || (value instanceof Collection && ((Collection) value).isEmpty())) {
      if (existValue != null) {
        LOG.info("Removing property - {} value from vertex {}", propertyName, vertex);
        vertex.removeProperty(propertyName);
      }
    } else {
      if (!value.equals(existValue)) {
        vertex.setProperty(propertyName, value);
      }
    }
  }

  public static void addProperty(Vertex vertex, String propertyName, Object value) {
    LOG.debug("Setting property {} = \"{}\" to vertex {}", propertyName, value, vertex);
    ((TitanVertex) vertex).addProperty(propertyName, value);
  }

  public Edge removeRelation(String edgeId, boolean cascade) {
    LOG.debug("Removing edge with id {}", edgeId);
    final Edge edge = titanGraph.getEdge(edgeId);
    titanGraph.removeEdge(edge);
    LOG.info("Removed edge {}", edge);
    if (cascade) {
      Vertex referredVertex = edge.getVertex(Direction.IN);
      titanGraph.removeVertex(referredVertex);
      LOG.info("Removed vertex {}", referredVertex);
    }
    return edge;
  }

  public Vertex getVertexForGUID(String guid) throws EntityNotFoundException {
    return getVertexForProperty(Constants.GUID_PROPERTY_KEY, guid);
  }

  public Vertex getVertexForProperty(String propertyKey, Object value)
      throws EntityNotFoundException {
    Vertex instanceVertex = findVertex(propertyKey, value);
    if (instanceVertex == null) {
      LOG.debug("Could not find a vertex with {}={}", propertyKey, value);
      throw new EntityNotFoundException(
          "Could not find an entity in the repository with " + propertyKey + "=" + value);
    } else {
      LOG.debug("Found a vertex {} with {}={}", instanceVertex, propertyKey, value);
    }

    return instanceVertex;
  }

  public static String getQualifiedFieldName(
      ITypedInstance typedInstance, AttributeInfo attributeInfo) throws AtlasException {
    IDataType dataType = typeSystem.getDataType(IDataType.class, typedInstance.getTypeName());
    return getQualifiedFieldName(dataType, attributeInfo.name);
  }

  public static String getQualifiedFieldName(IDataType dataType, String attributeName)
      throws AtlasException {
    return dataType.getTypeCategory() == DataTypes.TypeCategory.STRUCT
        ? dataType.getName() + "." + attributeName
        // else class or trait
        : ((HierarchicalType) dataType).getQualifiedName(attributeName);
  }

  public static String getTraitLabel(String typeName, String attrName) {
    return typeName + "." + attrName;
  }

  public static List<String> getTraitNames(Vertex entityVertex) {
    ArrayList<String> traits = new ArrayList<>();
    for (TitanProperty property :
        ((TitanVertex) entityVertex).getProperties(Constants.TRAIT_NAMES_PROPERTY_KEY)) {
      traits.add((String) property.getValue());
    }

    return traits;
  }

  public static String getEdgeLabel(ITypedInstance typedInstance, AttributeInfo aInfo)
      throws AtlasException {
    IDataType dataType = typeSystem.getDataType(IDataType.class, typedInstance.getTypeName());
    return getEdgeLabel(dataType, aInfo);
  }

  public static String getEdgeLabel(IDataType dataType, AttributeInfo aInfo) throws AtlasException {
    return GraphHelper.EDGE_LABEL_PREFIX + getQualifiedFieldName(dataType, aInfo.name);
  }

  public static Id getIdFromVertex(String dataTypeName, Vertex vertex) {
    return new Id(
        vertex.<String>getProperty(Constants.GUID_PROPERTY_KEY),
        vertex.<Integer>getProperty(Constants.VERSION_PROPERTY_KEY),
        dataTypeName);
  }

  public static String getTypeName(Vertex instanceVertex) {
    return instanceVertex.getProperty(Constants.ENTITY_TYPE_PROPERTY_KEY);
  }

  /**
   * For the given type, finds an unique attribute and checks if there is an existing instance with
   * the same unique value
   *
   * @param classType
   * @param instance
   * @return
   * @throws AtlasException
   */
  public Vertex getVertexForInstanceByUniqueAttribute(
      ClassType classType, IReferenceableInstance instance) throws AtlasException {

    Vertex result = null;
    for (AttributeInfo attributeInfo : classType.fieldMapping().fields.values()) {
      if (attributeInfo.isUnique) {
        String propertyKey = getQualifiedFieldName(classType, attributeInfo.name);
        try {
          result = getVertexForProperty(propertyKey, instance.get(attributeInfo.name));
          LOG.debug(
              "Found vertex by unique attribute : "
                  + propertyKey
                  + "="
                  + instance.get(attributeInfo.name));
        } catch (EntityNotFoundException e) {
          // Its ok if there is no entity with the same unique value
        }
      }
    }

    return result;
  }

  public static void dumpToLog(final Graph graph) {
    LOG.debug("*******************Graph Dump****************************");
    LOG.debug("Vertices of {}", graph);
    for (Vertex vertex : graph.getVertices()) {
      LOG.debug(vertexString(vertex));
    }

    LOG.debug("Edges of {}", graph);
    for (Edge edge : graph.getEdges()) {
      LOG.debug(edgeString(edge));
    }
    LOG.debug("*******************Graph Dump****************************");
  }
}
Ejemplo n.º 6
0
 public static String getEdgeLabel(ITypedInstance typedInstance, AttributeInfo aInfo)
     throws AtlasException {
   IDataType dataType = typeSystem.getDataType(IDataType.class, typedInstance.getTypeName());
   return getEdgeLabel(dataType, aInfo);
 }
Ejemplo n.º 7
0
 public static String getQualifiedFieldName(
     ITypedInstance typedInstance, AttributeInfo attributeInfo) throws AtlasException {
   IDataType dataType = typeSystem.getDataType(IDataType.class, typedInstance.getTypeName());
   return getQualifiedFieldName(dataType, attributeInfo.name);
 }
 protected AttributeInfo getAttributeForEdge(String edgLabel) throws AtlasException {
   AtlasEdgeLabel atlasEdgeLabel = new AtlasEdgeLabel(edgLabel);
   IDataType referenceType = typeSystem.getDataType(IDataType.class, atlasEdgeLabel.getTypeName());
   return getFieldMapping(referenceType).fields.get(atlasEdgeLabel.getAttributeName());
 }
  /**
   * Deletes the edge between outvertex and inVertex. The edge is for attribute attributeName of
   * outVertex
   *
   * @param outVertex
   * @param inVertex
   * @param attributeName
   * @throws AtlasException
   */
  protected void deleteEdgeBetweenVertices(Vertex outVertex, Vertex inVertex, String attributeName)
      throws AtlasException {
    LOG.debug(
        "Removing edge from {} to {} with attribute name {}",
        string(outVertex),
        string(inVertex),
        attributeName);
    String typeName = GraphHelper.getTypeName(outVertex);
    String outId = GraphHelper.getIdFromVertex(outVertex);
    Id.EntityState state = GraphHelper.getState(outVertex);
    if ((outId != null && RequestContext.get().isDeletedEntity(outId))
        || state == Id.EntityState.DELETED) {
      // If the reference vertex is marked for deletion, skip updating the reference
      return;
    }

    IDataType type = typeSystem.getDataType(IDataType.class, typeName);
    AttributeInfo attributeInfo = getFieldMapping(type).fields.get(attributeName);
    String propertyName = GraphHelper.getQualifiedFieldName(type, attributeName);
    String edgeLabel = EDGE_LABEL_PREFIX + propertyName;
    Edge edge = null;

    switch (attributeInfo.dataType().getTypeCategory()) {
      case CLASS:
        // If its class attribute, its the only edge between two vertices
        if (attributeInfo.multiplicity.nullAllowed()) {
          edge = GraphHelper.getEdgeForLabel(outVertex, edgeLabel);
          if (shouldUpdateReverseAttribute) {
            GraphHelper.setProperty(outVertex, propertyName, null);
          }
        } else {
          // Cannot unset a required attribute.
          throw new NullRequiredAttributeException(
              "Cannot unset required attribute "
                  + GraphHelper.getQualifiedFieldName(type, attributeName)
                  + " on "
                  + string(outVertex)
                  + " edge = "
                  + edgeLabel);
        }
        break;

      case ARRAY:
        // If its array attribute, find the right edge between the two vertices and update array
        // property
        List<String> elements = outVertex.getProperty(propertyName);
        if (elements != null) {
          elements =
              new ArrayList<>(
                  elements); // Make a copy, else list.remove reflects on titan.getProperty()
          for (String elementEdgeId : elements) {
            Edge elementEdge = graphHelper.getEdgeByEdgeId(outVertex, edgeLabel, elementEdgeId);
            if (elementEdge == null) {
              continue;
            }

            Vertex elementVertex = elementEdge.getVertex(Direction.IN);
            if (elementVertex.getId().toString().equals(inVertex.getId().toString())) {
              edge = elementEdge;

              // TODO element.size includes deleted items as well. should exclude
              if (!attributeInfo.multiplicity.nullAllowed()
                  && elements.size() <= attributeInfo.multiplicity.lower) {
                // Deleting this edge would violate the attribute's lower bound.
                throw new NullRequiredAttributeException(
                    "Cannot remove array element from required attribute "
                        + GraphHelper.getQualifiedFieldName(type, attributeName)
                        + " on "
                        + string(outVertex)
                        + " "
                        + string(elementEdge));
              }

              if (shouldUpdateReverseAttribute) {
                // if composite attribute, remove the reference as well. else, just remove the edge
                // for example, when table is deleted, process still references the table
                // but when column is deleted, table will not reference the deleted column
                LOG.debug(
                    "Removing edge {} from the array attribute {}",
                    string(elementEdge),
                    attributeName);
                elements.remove(elementEdge.getId().toString());
                GraphHelper.setProperty(outVertex, propertyName, elements);
                break;
              }
            }
          }
        }
        break;

      case MAP:
        // If its map attribute, find the right edge between two vertices and update map property
        List<String> keys = outVertex.getProperty(propertyName);
        if (keys != null) {
          keys =
              new ArrayList<>(
                  keys); // Make a copy, else list.remove reflects on titan.getProperty()
          for (String key : keys) {
            String keyPropertyName = GraphHelper.getQualifiedNameForMapKey(propertyName, key);
            String mapEdgeId = outVertex.getProperty(keyPropertyName);
            Edge mapEdge = graphHelper.getEdgeByEdgeId(outVertex, keyPropertyName, mapEdgeId);
            Vertex mapVertex = mapEdge.getVertex(Direction.IN);
            if (mapVertex.getId().toString().equals(inVertex.getId().toString())) {
              // TODO keys.size includes deleted items as well. should exclude
              if (attributeInfo.multiplicity.nullAllowed()
                  || keys.size() > attributeInfo.multiplicity.lower) {
                edge = mapEdge;
              } else {
                // Deleting this entry would violate the attribute's lower bound.
                throw new NullRequiredAttributeException(
                    "Cannot remove map entry "
                        + keyPropertyName
                        + " from required attribute "
                        + GraphHelper.getQualifiedFieldName(type, attributeName)
                        + " on "
                        + string(outVertex)
                        + " "
                        + string(mapEdge));
              }

              if (shouldUpdateReverseAttribute) {
                // remove this key
                LOG.debug(
                    "Removing edge {}, key {} from the map attribute {}",
                    string(mapEdge),
                    key,
                    attributeName);
                keys.remove(key);
                GraphHelper.setProperty(outVertex, propertyName, keys);
                GraphHelper.setProperty(outVertex, keyPropertyName, null);
              }
              break;
            }
          }
        }
        break;

      case STRUCT:
      case TRAIT:
        break;

      default:
        throw new IllegalStateException(
            "There can't be an edge from "
                + string(outVertex)
                + " to "
                + string(inVertex)
                + " with attribute name "
                + attributeName
                + " which is not class/array/map attribute");
    }

    if (edge != null) {
      deleteEdge(edge, false);
      RequestContext requestContext = RequestContext.get();
      GraphHelper.setProperty(
          outVertex,
          Constants.MODIFICATION_TIMESTAMP_PROPERTY_KEY,
          requestContext.getRequestTime());
      requestContext.recordEntityUpdate(outId);
    }
  }
  /**
   * Deleting any type vertex. Goes over the complex attributes and removes the references
   *
   * @param instanceVertex
   * @throws AtlasException
   */
  protected void deleteTypeVertex(Vertex instanceVertex, boolean force) throws AtlasException {
    LOG.debug("Deleting {}", string(instanceVertex));
    String typeName = GraphHelper.getTypeName(instanceVertex);
    IDataType type = typeSystem.getDataType(IDataType.class, typeName);
    FieldMapping fieldMapping = getFieldMapping(type);

    for (AttributeInfo attributeInfo : fieldMapping.fields.values()) {
      LOG.debug("Deleting attribute {} for {}", attributeInfo.name, string(instanceVertex));
      String edgeLabel = GraphHelper.getEdgeLabel(type, attributeInfo);

      switch (attributeInfo.dataType().getTypeCategory()) {
        case CLASS:
          // If its class attribute, delete the reference
          deleteEdgeReference(
              instanceVertex, edgeLabel, DataTypes.TypeCategory.CLASS, attributeInfo.isComposite);
          break;

        case STRUCT:
          // If its struct attribute, delete the reference
          deleteEdgeReference(instanceVertex, edgeLabel, DataTypes.TypeCategory.STRUCT, false);
          break;

        case ARRAY:
          // For array attribute, if the element is struct/class, delete all the references
          IDataType elementType = ((DataTypes.ArrayType) attributeInfo.dataType()).getElemType();
          DataTypes.TypeCategory elementTypeCategory = elementType.getTypeCategory();
          if (elementTypeCategory == DataTypes.TypeCategory.STRUCT
              || elementTypeCategory == DataTypes.TypeCategory.CLASS) {
            Iterator<Edge> edges = GraphHelper.getOutGoingEdgesByLabel(instanceVertex, edgeLabel);
            if (edges != null) {
              while (edges.hasNext()) {
                Edge edge = edges.next();
                deleteEdgeReference(
                    edge, elementType.getTypeCategory(), attributeInfo.isComposite, false);
              }
            }
          }
          break;

        case MAP:
          // For map attribute, if the value type is struct/class, delete all the references
          DataTypes.MapType mapType = (DataTypes.MapType) attributeInfo.dataType();
          DataTypes.TypeCategory valueTypeCategory = mapType.getValueType().getTypeCategory();
          String propertyName = GraphHelper.getQualifiedFieldName(type, attributeInfo.name);

          if (valueTypeCategory == DataTypes.TypeCategory.STRUCT
              || valueTypeCategory == DataTypes.TypeCategory.CLASS) {
            List<String> keys = instanceVertex.getProperty(propertyName);
            if (keys != null) {
              for (String key : keys) {
                String mapEdgeLabel = GraphHelper.getQualifiedNameForMapKey(edgeLabel, key);
                deleteEdgeReference(
                    instanceVertex, mapEdgeLabel, valueTypeCategory, attributeInfo.isComposite);
              }
            }
          }
      }
    }

    deleteVertex(instanceVertex, force);
  }
 @Test
 public void testStore() throws AtlasException {
   ImmutableList<String> typeNames = ts.getTypeNames();
   typeStore.store(ts, typeNames);
   dumpGraph();
 }
 @AfterClass
 public void tearDown() throws Exception {
   ts.reset();
   AtlasGraphProvider.cleanup();
 }
 @BeforeClass
 public void setUp() throws Exception {
   ts = TypeSystem.getInstance();
   ts.reset();
   TestUtils.defineDeptEmployeeTypes(ts);
 }
  @Test(dependsOnMethods = "testStore")
  public void testTypeUpdate() throws Exception {
    // Add enum value
    String _description = "_description_updated";
    EnumTypeDefinition orgLevelEnum =
        new EnumTypeDefinition(
            "OrgLevel",
            "OrgLevel" + _description,
            new EnumValue("L1", 1),
            new EnumValue("L2", 2),
            new EnumValue("L3", 3));

    // Add attribute
    StructTypeDefinition addressDetails =
        createStructTypeDef(
            "Address",
            createRequiredAttrDef("street", DataTypes.STRING_TYPE),
            createRequiredAttrDef("city", DataTypes.STRING_TYPE),
            createOptionalAttrDef("state", DataTypes.STRING_TYPE));

    HierarchicalTypeDefinition<ClassType> deptTypeDef =
        createClassTypeDef(
            "Department",
            "Department" + _description,
            ImmutableSet.<String>of(),
            createRequiredAttrDef("name", DataTypes.STRING_TYPE),
            new AttributeDefinition(
                "employees",
                String.format("array<%s>", "Person"),
                Multiplicity.OPTIONAL,
                true,
                "department"));
    TypesDef typesDef =
        TypesUtil.getTypesDef(
            ImmutableList.of(orgLevelEnum),
            ImmutableList.of(addressDetails),
            ImmutableList.<HierarchicalTypeDefinition<TraitType>>of(),
            ImmutableList.of(deptTypeDef));

    Map<String, IDataType> typesAdded = ts.updateTypes(typesDef);
    typeStore.store(ts, ImmutableList.copyOf(typesAdded.keySet()));

    verifyEdges();

    // Validate the updated types
    TypesDef types = typeStore.restore();
    ts.reset();
    ts.defineTypes(types);

    // Assert new enum value
    EnumType orgLevel = ts.getDataType(EnumType.class, orgLevelEnum.name);
    Assert.assertEquals(orgLevel.name, orgLevelEnum.name);
    Assert.assertEquals(orgLevel.description, orgLevelEnum.description);
    Assert.assertEquals(orgLevel.values().size(), orgLevelEnum.enumValues.length);
    Assert.assertEquals(orgLevel.fromValue("L3").ordinal, 3);

    // Assert new attribute
    StructType addressType = ts.getDataType(StructType.class, addressDetails.typeName);
    Assert.assertEquals(addressType.numFields, 3);
    Assert.assertEquals(
        addressType.fieldMapping.fields.get("state").dataType(), DataTypes.STRING_TYPE);

    // Updating the definition again shouldn't add another edge
    typesDef =
        TypesUtil.getTypesDef(
            ImmutableList.<EnumTypeDefinition>of(),
            ImmutableList.<StructTypeDefinition>of(),
            ImmutableList.<HierarchicalTypeDefinition<TraitType>>of(),
            ImmutableList.of(deptTypeDef));
    typesAdded = ts.updateTypes(typesDef);
    typeStore.store(ts, ImmutableList.copyOf(typesAdded.keySet()));
    verifyEdges();
  }
/** An implementation backed by a Graph database provided as a Graph Service. */
@Singleton
public class GraphBackedMetadataRepository implements MetadataRepository {

  private static final Logger LOG = LoggerFactory.getLogger(GraphBackedMetadataRepository.class);

  private static TypeSystem typeSystem = TypeSystem.getInstance();

  private static final GraphHelper graphHelper = GraphHelper.getInstance();

  private final TitanGraph titanGraph;

  private DeleteHandler deleteHandler;

  private GraphToTypedInstanceMapper graphToInstanceMapper;

  @Inject
  public GraphBackedMetadataRepository(
      GraphProvider<TitanGraph> graphProvider, DeleteHandler deleteHandler) {
    this.titanGraph = graphProvider.get();
    graphToInstanceMapper = new GraphToTypedInstanceMapper(titanGraph);
    this.deleteHandler = deleteHandler;
  }

  public GraphToTypedInstanceMapper getGraphToInstanceMapper() {
    return graphToInstanceMapper;
  }

  @Override
  public String getTypeAttributeName() {
    return Constants.ENTITY_TYPE_PROPERTY_KEY;
  }

  @Override
  public String getStateAttributeName() {
    return Constants.STATE_PROPERTY_KEY;
  }

  /**
   * Returns the property key used to store super type names.
   *
   * @return property key used to store super type names.
   */
  @Override
  public String getSuperTypeAttributeName() {
    return Constants.SUPER_TYPES_PROPERTY_KEY;
  }

  public String getIdAttributeName() {
    return Constants.GUID_PROPERTY_KEY;
  }

  @Override
  public String getTraitLabel(IDataType<?> dataType, String traitName) {
    return GraphHelper.getTraitLabel(dataType.getName(), traitName);
  }

  @Override
  public String getFieldNameInVertex(IDataType<?> dataType, AttributeInfo aInfo)
      throws AtlasException {
    if (aInfo.name.startsWith(Constants.INTERNAL_PROPERTY_KEY_PREFIX)) {
      return aInfo.name;
    }
    return GraphHelper.getQualifiedFieldName(dataType, aInfo.name);
  }

  public String getFieldNameInVertex(IDataType<?> dataType, String attrName) throws AtlasException {
    return GraphHelper.getQualifiedFieldName(dataType, attrName);
  }

  @Override
  public String getEdgeLabel(IDataType<?> dataType, AttributeInfo aInfo) throws AtlasException {
    return GraphHelper.getEdgeLabel(dataType, aInfo);
  }

  @Override
  @GraphTransaction
  public List<String> createEntities(ITypedReferenceableInstance... entities)
      throws RepositoryException, EntityExistsException {
    LOG.debug("adding entities={}", entities);
    try {
      TypedInstanceToGraphMapper instanceToGraphMapper =
          new TypedInstanceToGraphMapper(graphToInstanceMapper, deleteHandler);
      instanceToGraphMapper.mapTypedInstanceToGraph(
          TypedInstanceToGraphMapper.Operation.CREATE, entities);
      return RequestContext.get().getCreatedEntityIds();
    } catch (EntityExistsException e) {
      throw e;
    } catch (AtlasException e) {
      throw new RepositoryException(e);
    }
  }

  @Override
  @GraphTransaction
  public ITypedReferenceableInstance getEntityDefinition(String guid)
      throws RepositoryException, EntityNotFoundException {
    LOG.debug("Retrieving entity with guid={}", guid);

    Vertex instanceVertex = graphHelper.getVertexForGUID(guid);

    try {
      return graphToInstanceMapper.mapGraphToTypedInstance(guid, instanceVertex);
    } catch (AtlasException e) {
      throw new RepositoryException(e);
    }
  }

  @Override
  @GraphTransaction
  public ITypedReferenceableInstance getEntityDefinition(
      String entityType, String attribute, Object value) throws AtlasException {
    LOG.debug("Retrieving entity with type={} and {}={}", entityType, attribute, value);
    IDataType type = typeSystem.getDataType(IDataType.class, entityType);
    String propertyKey = getFieldNameInVertex(type, attribute);
    Vertex instanceVertex =
        graphHelper.findVertex(
            propertyKey,
            value,
            Constants.ENTITY_TYPE_PROPERTY_KEY,
            entityType,
            Constants.STATE_PROPERTY_KEY,
            Id.EntityState.ACTIVE.name());

    String guid = instanceVertex.getProperty(Constants.GUID_PROPERTY_KEY);
    return graphToInstanceMapper.mapGraphToTypedInstance(guid, instanceVertex);
  }

  @Override
  @GraphTransaction
  public List<String> getEntityList(String entityType) throws RepositoryException {
    LOG.debug("Retrieving entity list for type={}", entityType);
    GraphQuery query = titanGraph.query().has(Constants.ENTITY_TYPE_PROPERTY_KEY, entityType);
    Iterator<Vertex> results = query.vertices().iterator();
    if (!results.hasNext()) {
      return Collections.emptyList();
    }

    ArrayList<String> entityList = new ArrayList<>();
    while (results.hasNext()) {
      Vertex vertex = results.next();
      entityList.add(vertex.<String>getProperty(Constants.GUID_PROPERTY_KEY));
    }

    return entityList;
  }

  /**
   * Gets the list of trait names for a given entity represented by a guid.
   *
   * @param guid globally unique identifier for the entity
   * @return a list of trait names for the given entity guid
   * @throws RepositoryException
   */
  @Override
  @GraphTransaction
  public List<String> getTraitNames(String guid) throws AtlasException {
    LOG.debug("Retrieving trait names for entity={}", guid);
    Vertex instanceVertex = graphHelper.getVertexForGUID(guid);
    return GraphHelper.getTraitNames(instanceVertex);
  }

  /**
   * Adds a new trait to an existing entity represented by a guid.
   *
   * @param guid globally unique identifier for the entity
   * @param traitInstance trait instance that needs to be added to entity
   * @throws RepositoryException
   */
  @Override
  @GraphTransaction
  public void addTrait(String guid, ITypedStruct traitInstance) throws RepositoryException {
    Preconditions.checkNotNull(traitInstance, "Trait instance cannot be null");
    final String traitName = traitInstance.getTypeName();
    LOG.debug("Adding a new trait={} for entity={}", traitName, guid);

    try {
      Vertex instanceVertex = graphHelper.getVertexForGUID(guid);

      // add the trait instance as a new vertex
      final String typeName = GraphHelper.getTypeName(instanceVertex);

      TypedInstanceToGraphMapper instanceToGraphMapper =
          new TypedInstanceToGraphMapper(graphToInstanceMapper, deleteHandler);
      instanceToGraphMapper.mapTraitInstanceToVertex(
          traitInstance, typeSystem.getDataType(ClassType.class, typeName), instanceVertex);

      // update the traits in entity once adding trait instance is successful
      GraphHelper.addProperty(instanceVertex, Constants.TRAIT_NAMES_PROPERTY_KEY, traitName);
      GraphHelper.setProperty(
          instanceVertex,
          Constants.MODIFICATION_TIMESTAMP_PROPERTY_KEY,
          RequestContext.get().getRequestTime());

    } catch (RepositoryException e) {
      throw e;
    } catch (Exception e) {
      throw new RepositoryException(e);
    }
  }

  /**
   * Deletes a given trait from an existing entity represented by a guid.
   *
   * @param guid globally unique identifier for the entity
   * @param traitNameToBeDeleted name of the trait
   * @throws RepositoryException
   */
  @Override
  @GraphTransaction
  public void deleteTrait(String guid, String traitNameToBeDeleted)
      throws TraitNotFoundException, EntityNotFoundException, RepositoryException {
    LOG.debug("Deleting trait={} from entity={}", traitNameToBeDeleted, guid);

    Vertex instanceVertex = graphHelper.getVertexForGUID(guid);

    List<String> traitNames = GraphHelper.getTraitNames(instanceVertex);
    if (!traitNames.contains(traitNameToBeDeleted)) {
      throw new TraitNotFoundException(
          "Could not find trait="
              + traitNameToBeDeleted
              + " in the repository for entity: "
              + guid);
    }

    try {
      final String entityTypeName = GraphHelper.getTypeName(instanceVertex);
      String relationshipLabel = GraphHelper.getTraitLabel(entityTypeName, traitNameToBeDeleted);
      Edge edge = GraphHelper.getEdgeForLabel(instanceVertex, relationshipLabel);
      deleteHandler.deleteEdgeReference(edge, DataTypes.TypeCategory.TRAIT, false, true);

      // update the traits in entity once trait removal is successful
      traitNames.remove(traitNameToBeDeleted);
      updateTraits(instanceVertex, traitNames);
    } catch (Exception e) {
      throw new RepositoryException(e);
    }
  }

  private void updateTraits(Vertex instanceVertex, List<String> traitNames) {
    // remove the key
    instanceVertex.removeProperty(Constants.TRAIT_NAMES_PROPERTY_KEY);

    // add it back again
    for (String traitName : traitNames) {
      GraphHelper.addProperty(instanceVertex, Constants.TRAIT_NAMES_PROPERTY_KEY, traitName);
    }
    GraphHelper.setProperty(
        instanceVertex,
        Constants.MODIFICATION_TIMESTAMP_PROPERTY_KEY,
        RequestContext.get().getRequestTime());
  }

  @Override
  @GraphTransaction
  public AtlasClient.EntityResult updateEntities(ITypedReferenceableInstance... entitiesUpdated)
      throws RepositoryException {
    LOG.debug("updating entity {}", entitiesUpdated);
    try {
      TypedInstanceToGraphMapper instanceToGraphMapper =
          new TypedInstanceToGraphMapper(graphToInstanceMapper, deleteHandler);
      instanceToGraphMapper.mapTypedInstanceToGraph(
          TypedInstanceToGraphMapper.Operation.UPDATE_FULL, entitiesUpdated);
      RequestContext requestContext = RequestContext.get();
      return new AtlasClient.EntityResult(
          requestContext.getCreatedEntityIds(),
          requestContext.getUpdatedEntityIds(),
          requestContext.getDeletedEntityIds());
    } catch (AtlasException e) {
      throw new RepositoryException(e);
    }
  }

  @Override
  @GraphTransaction
  public AtlasClient.EntityResult updatePartial(ITypedReferenceableInstance entity)
      throws RepositoryException {
    LOG.debug("updating entity {}", entity);
    try {
      TypedInstanceToGraphMapper instanceToGraphMapper =
          new TypedInstanceToGraphMapper(graphToInstanceMapper, deleteHandler);
      instanceToGraphMapper.mapTypedInstanceToGraph(
          TypedInstanceToGraphMapper.Operation.UPDATE_PARTIAL, entity);
      RequestContext requestContext = RequestContext.get();
      return new AtlasClient.EntityResult(
          requestContext.getCreatedEntityIds(),
          requestContext.getUpdatedEntityIds(),
          requestContext.getDeletedEntityIds());
    } catch (AtlasException e) {
      throw new RepositoryException(e);
    }
  }

  @Override
  @GraphTransaction
  public AtlasClient.EntityResult deleteEntities(List<String> guids) throws RepositoryException {

    if (guids == null || guids.size() == 0) {
      throw new IllegalArgumentException("guids must be non-null and non-empty");
    }

    for (String guid : guids) {
      if (guid == null) {
        LOG.warn("deleteEntities: Ignoring null guid");
        continue;
      }
      try {
        Vertex instanceVertex = graphHelper.getVertexForGUID(guid);
        deleteHandler.deleteEntity(instanceVertex);
      } catch (EntityNotFoundException e) {
        // Entity does not exist - treat as non-error, since the caller
        // wanted to delete the entity and it's already gone.
        LOG.info("Deletion request ignored for non-existent entity with guid " + guid);
        continue;
      } catch (AtlasException e) {
        throw new RepositoryException(e);
      }
    }
    RequestContext requestContext = RequestContext.get();
    return new AtlasClient.EntityResult(
        requestContext.getCreatedEntityIds(),
        requestContext.getUpdatedEntityIds(),
        requestContext.getDeletedEntityIds());
  }
}