in repository/src/main/java/org/apache/atlas/repository/graph/DeleteHandler.java [288:427]
protected void deleteEdgeBetweenVertices(AtlasVertex outVertex, AtlasVertex inVertex, String attributeName) throws AtlasException {
if (LOG.isDebugEnabled()) {
LOG.debug("Removing edge from {} to {} with attribute name {}", string(outVertex), string(inVertex),
attributeName);
}
String typeName = GraphHelper.getTypeName(outVertex);
String outId = GraphHelper.getGuid(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;
AtlasEdge 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 " + GraphHelper.getVertexDetails(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 (!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 "
+ GraphHelper.getVertexDetails(outVertex) + " " + GraphHelper.getEdgeDetails(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
if (LOG.isDebugEnabled()) {
LOG.debug("Removing edge {} from the array attribute {}", string(elementEdge),
attributeName);
}
// 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 (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 " + GraphHelper.getVertexDetails(outVertex) + " " + GraphHelper.getEdgeDetails(mapEdge));
}
if (shouldUpdateReverseAttribute) {
//remove this key
if (LOG.isDebugEnabled()) {
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 " + GraphHelper.getVertexDetails(outVertex) + " to "
+ GraphHelper.getVertexDetails(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());
GraphHelper.setProperty(outVertex, Constants.MODIFIED_BY_KEY, requestContext.getUser());
requestContext.recordEntityUpdate(outId);
}
}