feat(java,info): add remove vertex edge method (#773)

* add remove vertex edge, TODO: tests

* reformat only GraphInfo class, TODO: tests

* added basic tests for add and remove vertex

* format graphInfoTests

* format graphInfoTests

* refactoring 1

* added basic test for edges

* add test

* update filter

* update

* chores

---------

Co-authored-by: Selim Soufargi <ssoufargi.idealab.unical@gmail.com~>
Co-authored-by: yxk485490 <1320342065@qq.com>

Author: 3 people

maven-projects/info/src/main/java/org/apache/graphar/info/GraphInfo.java

@@ -179,6 +179,34 @@ public Optional<GraphInfo> addVertexAsNew(VertexInfo vertexInfo) {
                         edgeConcat2EdgeInfo));
     }
 
+    public Optional<GraphInfo> removeVertex(VertexInfo vertexInfo) {
+
+        if (vertexInfo == null || !hasVertexInfo(vertexInfo.getType())) {
+            return Optional.empty();
+        }
+
+        final List<VertexInfo> newVertexInfoList =
+                vertexInfos.stream()
+                        .filter(v -> !v.getType().equals(vertexInfo.getType()))
+                        .collect(Collectors.toList());
+
+        final Map<String, VertexInfo> newVertexInfoMap =
+                vertexType2VertexInfo.entrySet().stream()
+                        .filter(v -> !v.getKey().equals(vertexInfo.getType()))
+                        .collect(
+                                Collectors.toUnmodifiableMap(
+                                        Map.Entry::getKey, Map.Entry::getValue));
+        return Optional.of(
+                new GraphInfo(
+                        name,
+                        newVertexInfoList,
+                        edgeInfos,
+                        baseUri,
+                        version,
+                        newVertexInfoMap,
+                        edgeConcat2EdgeInfo));
+    }
+
     public Optional<GraphInfo> addEdgeAsNew(EdgeInfo edgeInfo) {
         if (edgeInfo == null
                 || hasEdgeInfo(
@@ -205,6 +233,38 @@ public Optional<GraphInfo> addEdgeAsNew(EdgeInfo edgeInfo) {
                         newEdgeConcat2EdgeInfo));
     }
 
+    public Optional<GraphInfo> removeEdge(EdgeInfo edgeInfo) {
+        if (edgeInfo == null
+                || !hasEdgeInfo(
+                        edgeInfo.getSrcType(), edgeInfo.getEdgeType(), edgeInfo.getDstType())) {
+            return Optional.empty();
+        }
+        final List<EdgeInfo> newEdgeInfos =
+                edgeInfos.stream()
+                        .filter(
+                                e ->
+                                        !(e.getSrcType().equals(edgeInfo.getSrcType())
+                                                && e.getDstType().equals(edgeInfo.getDstType())
+                                                && e.getEdgeType().equals(edgeInfo.getEdgeType())))
+                        .collect(Collectors.toList());
+
+        final Map<String, EdgeInfo> newEdgeConcat2EdgeInfo =
+                edgeConcat2EdgeInfo.entrySet().stream()
+                        .filter(e -> !e.getKey().equals(edgeInfo.getConcat()))
+                        .collect(
+                                Collectors.toUnmodifiableMap(
+                                        Map.Entry::getKey, Map.Entry::getValue));
+        return Optional.of(
+                new GraphInfo(
+                        name,
+                        vertexInfos,
+                        newEdgeInfos,
+                        baseUri,
+                        version,
+                        vertexType2VertexInfo,
+                        newEdgeConcat2EdgeInfo));
+    }
+
     public boolean hasVertexInfo(String type) {
         return vertexType2VertexInfo.containsKey(type);
     }

maven-projects/info/src/test/java/org/apache/graphar/info/GraphInfoTest.java

@@ -24,6 +24,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Optional;
 import org.apache.graphar.info.loader.GraphInfoLoader;
 import org.apache.graphar.info.loader.impl.LocalFileSystemStreamGraphInfoLoader;
 import org.apache.graphar.info.type.AdjListType;
@@ -110,6 +111,60 @@ public void testGraphInfoBasics() {
                 illegalArgumentException.getMessage());
         // test version gar/v1
         Assert.assertEquals(1, graphInfo.getVersion().getVersion());
+        // basic tests for addVertex and removeVertex
+        VertexInfo testingVertexInfo =
+                new VertexInfo(
+                        "test_vertex",
+                        100,
+                        Arrays.asList(TestUtil.pg1),
+                        "vertex/person/",
+                        "gar/v1");
+        GraphInfo testingVertexGraphInfo =
+                new GraphInfo("graphVertexTest", new ArrayList<>(), new ArrayList<>(), "", "");
+        // remove non-existent vertex from an empty graph
+        Assert.assertTrue(testingVertexGraphInfo.removeVertex(testingVertexInfo).isEmpty());
+        // add the created vertex on an empty graph
+        Optional<GraphInfo> addVertexAsNewGraph =
+                testingVertexGraphInfo.addVertexAsNew(testingVertexInfo);
+        Assert.assertTrue(addVertexAsNewGraph.isPresent());
+        testingVertexGraphInfo = addVertexAsNewGraph.get();
+        Assert.assertEquals(1, addVertexAsNewGraph.get().getVertexInfos().size());
+        // try to add the same vertex again
+        Assert.assertTrue(testingVertexGraphInfo.addVertexAsNew(testingVertexInfo).isEmpty());
+        // test remove vertex
+        addVertexAsNewGraph = testingVertexGraphInfo.removeVertex(testingVertexInfo);
+        Assert.assertTrue(addVertexAsNewGraph.isPresent());
+        Assert.assertEquals(0, addVertexAsNewGraph.get().getVertexInfos().size());
+
+        // same tests as vertices for edges
+        GraphInfo testingEdgeGraphInfo =
+                new GraphInfo("graphEdgeTest", new ArrayList<>(), new ArrayList<>(), "", "");
+        EdgeInfo testingEdgeInfo =
+                new EdgeInfo(
+                        "person",
+                        "knows",
+                        "person",
+                        1024,
+                        100,
+                        100,
+                        false,
+                        URI.create("edge/person_knows_person/"),
+                        "gar/v1",
+                        List.of(TestUtil.orderedBySource),
+                        List.of(TestUtil.pg3));
+        // remove non-existent edge from an empty graph
+        Assert.assertTrue(testingEdgeGraphInfo.removeEdge(testingEdgeInfo).isEmpty());
+        // add the created edge on an empty graph
+        Optional<GraphInfo> addEdgeAsNewGraph = testingEdgeGraphInfo.addEdgeAsNew(testingEdgeInfo);
+        Assert.assertTrue(addEdgeAsNewGraph.isPresent());
+        testingEdgeGraphInfo = addEdgeAsNewGraph.get();
+        Assert.assertEquals(1, addEdgeAsNewGraph.get().getEdgeInfos().size());
+        // try to add the same edge again
+        Assert.assertTrue(testingEdgeGraphInfo.addEdgeAsNew(testingEdgeInfo).isEmpty());
+        // test remove edge
+        addEdgeAsNewGraph = testingEdgeGraphInfo.removeEdge(testingEdgeInfo);
+        Assert.assertTrue(addEdgeAsNewGraph.isPresent());
+        Assert.assertEquals(0, addEdgeAsNewGraph.get().getEdgeInfos().size());
     }
 
     @Test