Add get node names method to Node class

rcljava/CMakeLists.txt

@@ -143,9 +143,7 @@ set(${PROJECT_NAME}_sources
   "src/main/java/org/ros2/rcljava/events/PublisherEventStatus.java"
   "src/main/java/org/ros2/rcljava/events/SubscriptionEventStatus.java"
   "src/main/java/org/ros2/rcljava/graph/NameAndTypes.java"
-  "src/main/java/org/ros2/rcljava/publisher/statuses/LivelinessLost.java"
-  "src/main/java/org/ros2/rcljava/publisher/statuses/OfferedDeadlineMissed.java"
-  "src/main/java/org/ros2/rcljava/publisher/statuses/OfferedQosIncompatible.java"
+  "src/main/java/org/ros2/rcljava/graph/NodeNameInfo.java"
   "src/main/java/org/ros2/rcljava/executors/AnyExecutable.java"
   "src/main/java/org/ros2/rcljava/executors/BaseExecutor.java"
   "src/main/java/org/ros2/rcljava/executors/Executor.java"
@@ -173,6 +171,9 @@ set(${PROJECT_NAME}_sources
   "src/main/java/org/ros2/rcljava/parameters/service/ParameterServiceImpl.java"
   "src/main/java/org/ros2/rcljava/publisher/Publisher.java"
   "src/main/java/org/ros2/rcljava/publisher/PublisherImpl.java"
+  "src/main/java/org/ros2/rcljava/publisher/statuses/LivelinessLost.java"
+  "src/main/java/org/ros2/rcljava/publisher/statuses/OfferedDeadlineMissed.java"
+  "src/main/java/org/ros2/rcljava/publisher/statuses/OfferedQosIncompatible.java"
   "src/main/java/org/ros2/rcljava/qos/policies/Durability.java"
   "src/main/java/org/ros2/rcljava/qos/policies/History.java"
   "src/main/java/org/ros2/rcljava/qos/policies/Liveliness.java"

rcljava/include/org_ros2_rcljava_node_NodeImpl.h

@@ -92,6 +92,15 @@ JNIEXPORT jlong
 JNICALL Java_org_ros2_rcljava_node_NodeImpl_nativeCreateTimerHandle(
   JNIEnv *, jclass, jlong, jlong, jlong);
 
+/*
+ * Class:     org_ros2_rcljava_node_NodeImpl
+ * Method:    nativeGetNodeNames
+ * Signature: (JLjava/util/List;)V
+ */
+JNIEXPORT void
+JNICALL Java_org_ros2_rcljava_node_NodeImpl_nativeGetNodeNames(
+  JNIEnv *, jclass, jlong, jobject);
+
 /*
  * Class:     org_ros2_rcljava_node_NodeImpl
  * Method:    nativeGetTopicNamesAndTypes

rcljava/src/main/cpp/org_ros2_rcljava_node_NodeImpl.cpp

@@ -254,6 +254,84 @@ Java_org_ros2_rcljava_node_NodeImpl_nativeCreateTimerHandle(
   return jtimer;
 }
 
+JNIEXPORT void JNICALL
+Java_org_ros2_rcljava_node_NodeImpl_nativeGetNodeNames(
+  JNIEnv * env, jclass, jlong handle, jobject jnode_names_info)
+{
+  rcl_node_t * node = reinterpret_cast<rcl_node_t *>(handle);
+  if (!node) {
+    rcljava_throw_exception(env, "java/lang/IllegalArgumentException", "node handle is NULL");
+    return;
+  }
+
+  jclass list_clazz = env->GetObjectClass(jnode_names_info);
+  jmethodID list_add_mid = env->GetMethodID(list_clazz, "add", "(Ljava/lang/Object;)Z");
+  RCLJAVA_COMMON_CHECK_FOR_EXCEPTION(env);
+  jclass node_info_clazz = env->FindClass("org/ros2/rcljava/graph/NodeNameInfo");
+  RCLJAVA_COMMON_CHECK_FOR_EXCEPTION(env);
+  jmethodID node_info_init_mid = env->GetMethodID(node_info_clazz, "<init>", "()V");
+  RCLJAVA_COMMON_CHECK_FOR_EXCEPTION(env);
+  jfieldID name_fid = env->GetFieldID(node_info_clazz, "name", "Ljava/lang/String;");
+  RCLJAVA_COMMON_CHECK_FOR_EXCEPTION(env);
+  jfieldID namespace_fid = env->GetFieldID(node_info_clazz, "namespace", "Ljava/lang/String;");
+  RCLJAVA_COMMON_CHECK_FOR_EXCEPTION(env);
+  jfieldID enclave_fid = env->GetFieldID(node_info_clazz, "enclave", "Ljava/lang/String;");
+  RCLJAVA_COMMON_CHECK_FOR_EXCEPTION(env);
+
+  rcl_allocator_t allocator = rcl_get_default_allocator();
+  rcutils_string_array_t node_names = rcutils_get_zero_initialized_string_array();
+  rcutils_string_array_t node_namespaces = rcutils_get_zero_initialized_string_array();
+  rcutils_string_array_t enclaves = rcutils_get_zero_initialized_string_array();
+
+  rcl_ret_t ret = rcl_get_node_names_with_enclaves(
+    node,
+    allocator,
+    &node_names,
+    &node_namespaces,
+    &enclaves);
+  RCLJAVA_COMMON_THROW_FROM_RCL(env, ret, "rcl_get_node_names_with_enclaves failed");
+  auto on_scope_exit = rcpputils::make_scope_exit(
+    [pnames = &node_names, pnamespaces = &node_namespaces, penclaves = &enclaves, env]() {
+      rcl_ret_t ret = rcutils_string_array_fini(pnames);
+      if (!env->ExceptionCheck() && RCL_RET_OK != ret) {
+        rcljava_throw_rclexception(env, ret, "failed to fini node names string array");
+      }
+      ret = rcutils_string_array_fini(pnamespaces);
+      if (!env->ExceptionCheck() && RCL_RET_OK != ret) {
+        rcljava_throw_rclexception(env, ret, "failed to fini node namespaces string array");
+      }
+      ret = rcutils_string_array_fini(penclaves);
+      if (!env->ExceptionCheck() && RCL_RET_OK != ret) {
+        rcljava_throw_rclexception(env, ret, "failed to fini enclaves string array");
+      }
+    }
+  );
+
+  if (node_names.size != node_namespaces.size || node_names.size != enclaves.size) {
+    rcljava_throw_exception(
+      env,
+      "java/lang/IllegalStateException",
+      "names, namespaces and enclaves array leghts don't match");
+    return;
+  }
+
+  for (size_t i = 0; i < node_names.size; i++) {
+    jstring jnode_name = env->NewStringUTF(node_names.data[i]);
+    RCLJAVA_COMMON_CHECK_FOR_EXCEPTION(env);
+    jstring jnode_namespace = env->NewStringUTF(node_namespaces.data[i]);
+    RCLJAVA_COMMON_CHECK_FOR_EXCEPTION(env);
+    jstring jenclave = env->NewStringUTF(enclaves.data[i]);
+    RCLJAVA_COMMON_CHECK_FOR_EXCEPTION(env);
+    jobject jitem = env->NewObject(node_info_clazz, node_info_init_mid);
+    RCLJAVA_COMMON_CHECK_FOR_EXCEPTION(env);
+    env->SetObjectField(jitem, name_fid, jnode_name);
+    env->SetObjectField(jitem, namespace_fid, jnode_namespace);
+    env->SetObjectField(jitem, enclave_fid, jenclave);
+    env->CallBooleanMethod(jnode_names_info, list_add_mid, jitem);
+    RCLJAVA_COMMON_CHECK_FOR_EXCEPTION(env);
+  }
+}
+
 JNIEXPORT void JNICALL
 Java_org_ros2_rcljava_node_NodeImpl_nativeGetTopicNamesAndTypes(
   JNIEnv * env, jclass, jlong handle, jobject jnames_and_types)

rcljava/src/main/java/org/ros2/rcljava/graph/NodeNameInfo.java

@@ -0,0 +1,68 @@
+/* Copyright 2020 Open Source Robotics Foundation, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.ros2.rcljava.graph;
+
+import java.util.Objects;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.ros2.rcljava.common.JNIUtils;
+
+/**
+ * Class that represents the queried information of a node in the graph.
+ */
+public class NodeNameInfo {
+  /// The node name
+  public String name;
+  /// The node namespace
+  public String namespace;
+  /// The security enclave of the node.
+  /**
+   * For further details, see:
+   * @{link http://design.ros2.org/articles/ros2_security_enclaves.html}
+   */
+  public String enclave;
+
+  /// Constructor
+  public NodeNameInfo(final String name, final String namespace, final String enclave) {
+    this.name = name;
+    this.namespace = namespace;
+    this.enclave = enclave;
+  }
+
+  /// Default constructor, used from jni.
+  private NodeNameInfo() {}
+
+  @Override
+  public boolean equals(Object o) {
+    if (o == this) {
+      return true;
+    }
+    if (!(o instanceof NodeNameInfo)) {
+      return false;
+    }
+    NodeNameInfo other = (NodeNameInfo) o;
+    return Objects.equals(this.name, other.name) &&
+      Objects.equals(this.namespace, other.namespace) &&
+      Objects.equals(this.enclave, other.enclave);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(this.name, this.namespace, this.enclave);
+  }
+}

rcljava/src/main/java/org/ros2/rcljava/node/Node.java

@@ -26,6 +26,7 @@
 import org.ros2.rcljava.consumers.TriConsumer;
 import org.ros2.rcljava.graph.EndpointInfo;
 import org.ros2.rcljava.graph.NameAndTypes;
+import org.ros2.rcljava.graph.NodeNameInfo;
 import org.ros2.rcljava.interfaces.Disposable;
 import org.ros2.rcljava.interfaces.MessageDefinition;
 import org.ros2.rcljava.interfaces.ServiceDefinition;
@@ -552,6 +553,12 @@ <T extends ServiceDefinition> Client<T> createClient(final Class<T> serviceType,
    */
   rcl_interfaces.msg.ListParametersResult listParameters(List<String> prefixes, long depth);
 
+  /**
+   * Returns a collection of node names that were detected in the ROS graph.
+   * See @{link NodeNameInfo} for more information about the return value.
+   */
+  Collection<NodeNameInfo> getNodeNames();
+
   /**
    * Return the topics names and types that were detected in the graph.
    * See @{link graph#NameAndTypes} for more information about the returned value.

rcljava/src/main/java/org/ros2/rcljava/node/NodeImpl.java

@@ -22,6 +22,7 @@
 import org.ros2.rcljava.concurrent.Callback;
 import org.ros2.rcljava.consumers.Consumer;
 import org.ros2.rcljava.consumers.TriConsumer;
+import org.ros2.rcljava.graph.NodeNameInfo;
 import org.ros2.rcljava.contexts.Context;
 import org.ros2.rcljava.graph.EndpointInfo;
 import org.ros2.rcljava.graph.NameAndTypes;
@@ -741,6 +742,14 @@ public rcl_interfaces.msg.ListParametersResult listParameters(
     }
   }
 
+  public final Collection<NodeNameInfo> getNodeNames() {
+    ArrayList<NodeNameInfo> nodeNames = new ArrayList();
+    nativeGetNodeNames(this.handle, nodeNames);
+    return nodeNames;
+  }
+
+  private native static final void nativeGetNodeNames(long handle, ArrayList<NodeNameInfo> nodeNames);
+
   public final Collection<NameAndTypes> getTopicNamesAndTypes() {
     Collection<NameAndTypes> namesAndTypes = new ArrayList();
     nativeGetTopicNamesAndTypes(this.handle, namesAndTypes);

rcljava/src/test/java/org/ros2/rcljava/node/NodeTest.java

@@ -45,6 +45,7 @@
 import org.ros2.rcljava.executors.SingleThreadedExecutor;
 import org.ros2.rcljava.graph.EndpointInfo;
 import org.ros2.rcljava.graph.NameAndTypes;
+import org.ros2.rcljava.graph.NodeNameInfo;
 import org.ros2.rcljava.node.Node;
 import org.ros2.rcljava.publisher.Publisher;
 import org.ros2.rcljava.qos.policies.Reliability;
@@ -867,6 +868,64 @@ public Node getNode() {
     assertEquals(0, subscriptionOne.getHandle());
     subscriptionTwo.dispose();
     assertEquals(0, subscriptionTwo.getHandle());
+    publisherNode.dispose();
+    assertEquals(0, publisherNode.getHandle());
+    subscriptionNodeOne.dispose();
+    assertEquals(0, subscriptionNodeOne.getHandle());
+    subscriptionNodeTwo.dispose();
+    assertEquals(0, subscriptionNodeTwo.getHandle());
+  }
+
+  @Test
+  public final void testGetNodeNames() throws Exception {
+    final Node node1 = RCLJava.createNode("test_get_node_names_1");
+    final Node node2 = RCLJava.createNode("test_get_node_names_2");
+    final Node node3 = RCLJava.createNode("test_get_node_names_3");
+
+    Consumer<Collection<NodeNameInfo>> validateNodeNameInfo =
+    new Consumer<Collection<NodeNameInfo>>() {
+      public void accept(final Collection<NodeNameInfo> nodeNamesInfo) {
+        assertEquals(4, nodeNamesInfo.size());
+        assertTrue(
+          "node 'test_node' was not discovered",
+          nodeNamesInfo.contains(new NodeNameInfo("test_node", "/", "/")));
+        assertTrue(
+          "node 'test_get_node_names_1' was not discovered",
+          nodeNamesInfo.contains(new NodeNameInfo("test_get_node_names_1", "/", "/")));
+        assertTrue(
+          "node 'test_get_node_names_2' was not discovered",
+          nodeNamesInfo.contains(new NodeNameInfo("test_get_node_names_1", "/", "/")));
+        assertTrue(
+          "node 'test_get_node_names_3' was not discovered",
+          nodeNamesInfo.contains(new NodeNameInfo("test_get_node_names_1", "/", "/")));
+      }
+    };
+
+    long start = System.currentTimeMillis();
+    boolean ok = false;
+    Collection<NodeNameInfo> nodeNamesInfo = null;
+    do {
+      nodeNamesInfo = this.node.getNodeNames();
+      try {
+        validateNodeNameInfo.accept(nodeNamesInfo);
+        ok = true;
+      } catch (AssertionError err) {
+        // ignore here, it's going to be validated again at the end.
+      }
+      // TODO(ivanpauno): We could wait for the graph guard condition to be triggered if that
+      // would be available.
+      try {
+        TimeUnit.MILLISECONDS.sleep(100);
+      } catch (InterruptedException err) {
+        // ignore
+      }
+    } while (!ok && System.currentTimeMillis() < start + 1000);
+    assertNotNull(nodeNamesInfo);
+    validateNodeNameInfo.accept(nodeNamesInfo);
+
+    node1.dispose();
+    node2.dispose();
+    node3.dispose();
   }
 
   @Test