[NLA-262] Improves getting subresource

alexandria-service/src/main/java/nl/knaw/huygens/alexandria/service/TinkerPopService.java

@@ -49,6 +49,7 @@
 import org.apache.commons.lang.NotImplementedException;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.tinkerpop.gremlin.structure.Element;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
 import org.jooq.lambda.Unchecked;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
@@ -234,17 +235,16 @@ public Optional<AlexandriaAnnotationBody> findAnnotationBodyWithTypeAndValue(Str
 
   @Override
   public Optional<AlexandriaResource> findSubresourceWithSubAndParentId(String sub, UUID parentId) {
-    // TODO: find the gremlin way to do this in one:
-    // in cypher: match (r:Resource{uuid:parentId})<-[:PART_OF]-(s:Resource{cargo:sub}) return s.uuid
     return storage.runInTransaction(//
-        () -> storage.find(ResourceVF.class)//
-            .has("cargo", sub)//
+        () -> storage.getResourceVertexTraversal()//
+            .has(Storage.IDENTIFIER_PROPERTY, parentId.toString())//
+            .in(ResourceVF.PART_OF)//
+            .has(ResourceVF.Properties.CARGO, sub)//
             .toList()//
-            .stream()//
-            .filter(r -> r.getParentResource() != null//
-                && r.getParentResource().getUuid().equals(parentId.toString()))//
+            .parallelStream()//
             .map(this::deframeResource)//
-            .findFirst());
+            .findAny()//
+    );
   }
 
   @Override
@@ -617,6 +617,11 @@ private AlexandriaAnnotation createAnnotation(AlexandriaTextLocator textLocator,
     return alexandriaAnnotation;
   }
 
+  private AlexandriaResource deframeResource(Vertex v) {
+    ResourceVF rvf = storage.frameVertex(v, ResourceVF.class);
+    return deframeResource(rvf);
+  }
+
   private AlexandriaResource deframeResource(ResourceVF rvf) {
     TentativeAlexandriaProvenance provenance = deframeProvenance(rvf);
     UUID uuid = getUUID(rvf);

alexandria-service/src/main/java/nl/knaw/huygens/alexandria/storage/Storage.java

@@ -10,12 +10,12 @@
  * it under the terms of the GNU General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
- * 
+ *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU General Public
  * License along with this program.  If not, see
  * <http://www.gnu.org/licenses/gpl-3.0.html>.
@@ -37,6 +37,7 @@
 import org.apache.tinkerpop.gremlin.structure.Element;
 import org.apache.tinkerpop.gremlin.structure.Graph;
 import org.apache.tinkerpop.gremlin.structure.Graph.Features.GraphFeatures;
+import org.apache.tinkerpop.gremlin.structure.T;
 import org.apache.tinkerpop.gremlin.structure.Vertex;
 import org.apache.tinkerpop.gremlin.structure.io.IoCore;
 import org.apache.tinkerpop.gremlin.structure.io.graphml.GraphMLIo;
@@ -177,6 +178,10 @@ public GraphTraversal<Vertex, Vertex> getVertexTraversal(Object... vertexIds) {
     return graph.traversal().V(vertexIds);
   }
 
+  public GraphTraversal<Vertex, Vertex> getResourceVertexTraversal(Object... vertexIds) {
+    return getVertexTraversal(vertexIds).has(T.label, "Resource");
+  }
+
   // graph methods
 
   public void removeExpiredTentatives(final Long threshold) {
@@ -253,6 +258,11 @@ public void destroy() {
     }
     // Log.info("destroy done");
   }
+
+  public <A extends AlexandriaVF> A frameVertex(Vertex v, Class<A> vfClass) {
+    return framedGraph.frame(v, vfClass);
+  }
+
   // - private methods - //
 
   private <A extends AlexandriaVF> FramedGraphTraversal<Object, A> find(final Class<A> vfClass, final UUID uuid) {

alexandria-service/src/main/java/nl/knaw/huygens/alexandria/storage/frames/ResourceVF.java

@@ -32,6 +32,9 @@
 
 @Vertex(Labels.RESOURCE)
 public abstract class ResourceVF extends AlexandriaVF {
+  public static class Properties {
+    public static final String CARGO = "cargo";
+  }
   public static final String PART_OF = "part_of";
 
   public abstract String getCargo();