in repository/src/main/java/org/apache/atlas/repository/store/graph/v1/DeleteHandlerV1.java [420:555]
protected void deleteEdgeBetweenVertices(AtlasVertex outVertex, AtlasVertex inVertex, AtlasAttribute attribute) throws AtlasBaseException {
LOG.debug("Removing edge from {} to {} with attribute name {}", string(outVertex), string(inVertex),
attribute.getName());
String typeName = GraphHelper.getTypeName(outVertex);
String outId = GraphHelper.getGuid(outVertex);
AtlasObjectId objId = new AtlasObjectId(outId, typeName);
AtlasEntity.Status state = AtlasGraphUtilsV1.getState(outVertex);
if (state == AtlasEntity.Status.DELETED || (outId != null && RequestContextV1.get().isDeletedEntity(objId))) {
//If the reference vertex is marked for deletion, skip updating the reference
return;
}
AtlasStructType parentType = (AtlasStructType) typeRegistry.getType(typeName);
String propertyName = AtlasGraphUtilsV1.getQualifiedAttributePropertyKey(parentType, attribute.getName());
String edgeLabel = EDGE_LABEL_PREFIX + propertyName;
AtlasEdge edge = null;
AtlasAttributeDef attrDef = attribute.getAttributeDef();
AtlasType attrType = attribute.getAttributeType();
switch (attrType.getTypeCategory()) {
case OBJECT_ID_TYPE:
//If its class attribute, its the only edge between two vertices
if (attrDef.getIsOptional()) {
edge = graphHelper.getEdgeForLabel(outVertex, edgeLabel);
if (shouldUpdateInverseReferences) {
GraphHelper.setProperty(outVertex, propertyName, null);
}
} else {
// Cannot unset a required attribute.
throw new AtlasBaseException("Cannot unset required attribute " + propertyName +
" on " + GraphHelper.vertexString(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 = GraphHelper.getListProperty(outVertex, propertyName);
if (elements != null) {
elements = new ArrayList<>(elements); //Make a copy, else list.remove reflects on titan.getProperty()
for (String elementEdgeId : elements) {
AtlasEdge elementEdge = graphHelper.getEdgeByEdgeId(outVertex, edgeLabel, elementEdgeId);
if (elementEdge == null) {
continue;
}
AtlasVertex elementVertex = elementEdge.getInVertex();
if (elementVertex.equals(inVertex)) {
edge = elementEdge;
//TODO element.size includes deleted items as well. should exclude
if (!attrDef.getIsOptional()
&& elements.size() <= attrDef.getValuesMinCount()) {
// Deleting this edge would violate the attribute's lower bound.
throw new AtlasBaseException(
"Cannot remove array element from required attribute " +
propertyName + " on "
+ GraphHelper.getVertexDetails(outVertex) + " " + GraphHelper.getEdgeDetails(elementEdge));
}
if (shouldUpdateInverseReferences) {
//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),
attribute.getName());
// Remove all occurrences of the edge ID from the list.
// This prevents dangling edge IDs (i.e. edge IDs for deleted edges)
// from the remaining in the list if there are duplicates.
elements.removeAll(Collections.singletonList(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 = GraphHelper.getListProperty(outVertex, 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 = GraphHelper.getSingleValuedProperty(outVertex, keyPropertyName, String.class);
AtlasEdge mapEdge = graphHelper.getEdgeByEdgeId(outVertex, keyPropertyName, mapEdgeId);
if(mapEdge != null) {
AtlasVertex mapVertex = mapEdge.getInVertex();
if (mapVertex.getId().toString().equals(inVertex.getId().toString())) {
//TODO keys.size includes deleted items as well. should exclude
if (attrDef.getIsOptional() || keys.size() > attrDef.getValuesMinCount()) {
edge = mapEdge;
} else {
// Deleting this entry would violate the attribute's lower bound.
throw new AtlasBaseException(
"Cannot remove map entry " + keyPropertyName + " from required attribute " +
propertyName + " on " + GraphHelper.getVertexDetails(outVertex) + " " + GraphHelper.getEdgeDetails(mapEdge));
}
if (shouldUpdateInverseReferences) {
//remove this key
LOG.debug("Removing edge {}, key {} from the map attribute {}", string(mapEdge), key,
attribute.getName());
keys.remove(key);
GraphHelper.setProperty(outVertex, propertyName, keys);
GraphHelper.setProperty(outVertex, keyPropertyName, null);
}
break;
}
}
}
}
break;
case STRUCT:
case CLASSIFICATION:
break;
default:
throw new IllegalStateException("There can't be an edge from " + GraphHelper.getVertexDetails(outVertex) + " to "
+ GraphHelper.getVertexDetails(inVertex) + " with attribute name " + attribute.getName() + " which is not class/array/map attribute. found " + attrType.getTypeCategory().name());
}
if (edge != null) {
deleteEdge(edge, false);
RequestContextV1 requestContext = RequestContextV1.get();
GraphHelper.setProperty(outVertex, Constants.MODIFICATION_TIMESTAMP_PROPERTY_KEY,
requestContext.getRequestTime());
GraphHelper.setProperty(outVertex, Constants.MODIFIED_BY_KEY, requestContext.getUser());
requestContext.recordEntityUpdate(new AtlasObjectId(outId, typeName));
}
}