Rosnode list (#304)

* expose list of nodes

* uncrustify

* review comments

* warn for memory leak

* extend year of copyright

rclcpp/include/rclcpp/node_interfaces/node_graph.hpp

@@ -1,4 +1,4 @@
-// Copyright 2016 Open Source Robotics Foundation, Inc.
+// Copyright 2016-2017 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.
@@ -59,6 +59,11 @@ public:
   std::map<std::string, std::string>
   get_topic_names_and_types() const;
 
+  RCLCPP_PUBLIC
+  virtual
+  std::vector<std::string>
+  get_node_names() const;
+
   RCLCPP_PUBLIC
   virtual
   size_t

rclcpp/include/rclcpp/node_interfaces/node_graph_interface.hpp

@@ -1,4 +1,4 @@
-// Copyright 2016 Open Source Robotics Foundation, Inc.
+// Copyright 2016-2017 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.
@@ -18,6 +18,7 @@
 #include <chrono>
 #include <map>
 #include <string>
+#include <vector>
 
 #include "rcl/guard_condition.h"
 
@@ -46,6 +47,12 @@ public:
   std::map<std::string, std::string>
   get_topic_names_and_types() const = 0;
 
+  /// Return a vector of existing node names (string).
+  RCLCPP_PUBLIC
+  virtual
+  std::vector<std::string>
+  get_node_names() const = 0;
+
   /// Return the number of publishers that are advertised on a given topic.
   RCLCPP_PUBLIC
   virtual

rclcpp/src/rclcpp/node_interfaces/node_graph.cpp

@@ -16,6 +16,7 @@
 
 #include <map>
 #include <string>
+#include <vector>
 
 #include "rcl/graph.h"
 #include "rclcpp/exceptions.hpp"
@@ -75,6 +76,37 @@ NodeGraph::get_topic_names_and_types() const
   return topics;
 }
 
+std::vector<std::string>
+NodeGraph::get_node_names() const
+{
+  rcl_string_array_t node_names_c =
+    rcl_get_zero_initialized_string_array();
+
+  auto ret = rcl_get_node_names(node_base_->get_rcl_node_handle(),
+      &node_names_c);
+  if (ret != RMW_RET_OK) {
+    if (rmw_destroy_node_names(&node_names_c) != RMW_RET_OK) {
+      RMW_SET_ERROR_MSG("Fatal: Leaking node_name memory.");
+    }
+    // *INDENT-OFF*
+    throw std::runtime_error(
+      std::string("could not get node names: ") + rmw_get_error_string_safe());
+    // *INDENT-ON*
+  }
+
+  std::vector<std::string> node_names(&node_names_c.data[0],
+    &node_names_c.data[0 + node_names_c.size]);
+  ret = rmw_destroy_node_names(&node_names_c);
+  if (ret != RMW_RET_OK) {
+    // *INDENT-OFF*
+    throw std::runtime_error(
+      std::string("could not destroy node names: ") + rmw_get_error_string_safe());
+    // *INDENT-ON*
+  }
+
+  return node_names;
+}
+
 size_t
 NodeGraph::count_publishers(const std::string & topic_name) const
 {