Add missing newline

Signed-off-by: Shane Loretz <sloretz@osrfoundation.org>

rclcpp/CMakeLists.txt

@@ -65,6 +65,7 @@ set(${PROJECT_NAME}_SRCS
   src/rclcpp/guard_condition.cpp
   src/rclcpp/init_options.cpp
   src/rclcpp/intra_process_manager.cpp
+  src/rclcpp/list_parameter_override_prefixes.cpp
   src/rclcpp/logger.cpp
   src/rclcpp/logging_mutex.cpp
   src/rclcpp/memory_strategies.cpp

rclcpp/include/rclcpp/list_parameter_override_prefixes.hpp

@@ -0,0 +1,67 @@
+// Copyright 2023 Intrisnic.ai
+//
+// 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.
+
+#ifndef RCLCPP__LIST_PARAMETER_OVERRIDE_PREFIXES_HPP_
+#define RCLCPP__LIST_PARAMETER_OVERRIDE_PREFIXES_HPP_
+
+#include <map>
+#include <string>
+#include <unordered_set>
+
+#include <rclcpp/node_interfaces/node_interfaces.hpp>
+#include <rclcpp/node_interfaces/node_parameters_interface.hpp>
+#include <rclcpp/parameter_value.hpp>
+
+namespace rclcpp
+{
+namespace detail
+{
+/** @brief Internal function for unit testing.
+ * @internal
+*/
+std::unordered_set<std::string>
+list_parameter_override_prefixes(
+  const std::map<std::string, rclcpp::ParameterValue> & overrides,
+  std::string prefix);
+}  // namespace detail
+
+/**
+ * @brief Get parameter overrides that have a given prefix
+ *
+ * Example:
+ *  Say the given parameter overrides are foo, foo.baz, foo.bar.baz, and foobar.baz
+ *  Given prefix "", this will return foo, and foobar
+ *  Given prefix "foo", this will return foo.baz and foo.bar
+ *  Given prefix "foo.bar", this will return foo.bar.baz
+ *  Given prefix "foo.baz", this will return an empty list
+ *
+ *  All overrides are searched and returned, so that this can be used to
+ *  conditionally declare parameters.
+ *  The returned names may or may not be valid parameters, but instead are
+ *  prefixes of valid parameters.
+ *  The prefix itself will never be in the returned output.
+ *
+ *
+ * @param[in] interfaces - The node interfaces used to get the parameter overrides
+ * @param[in] prefix - the parameter prefix
+ * @param[in] max_depth - how deep to return parameter override names, or 0 for
+ *    unlimited depth.
+*/
+std::unordered_set<std::string>
+list_parameter_override_prefixes(
+  node_interfaces::NodeInterfaces<node_interfaces::NodeParametersInterface> interfaces,
+  std::string prefix);
+}  // namespace rclcpp
+
+#endif  // RCLCPP__LIST_PARAMETER_OVERRIDE_PREFIXES_HPP_

rclcpp/src/rclcpp/list_parameter_override_prefixes.cpp

@@ -0,0 +1,66 @@
+// Copyright 2023 Intrisnic.ai
+//
+// 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.
+
+#include <rclcpp/list_parameter_override_prefixes.hpp>
+
+#include <cassert>
+#include <string>
+#include <unordered_set>
+
+
+namespace rclcpp
+{
+std::unordered_set<std::string>
+list_parameter_override_prefixes(
+  node_interfaces::NodeInterfaces<node_interfaces::NodeParametersInterface> interfaces,
+  std::string prefix)
+{
+  const std::map<std::string, rclcpp::ParameterValue> & overrides =
+    interfaces.get_node_parameters_interface()->get_parameter_overrides();
+  return detail::list_parameter_override_prefixes(overrides, prefix);
+}
+
+std::unordered_set<std::string>
+detail::list_parameter_override_prefixes(
+  const std::map<std::string, rclcpp::ParameterValue> & overrides,
+  std::string prefix)
+{
+  // TODO(sloretz) ROS 2 must have this in a header somewhere, right?
+  const char kParamSeparator = '.';
+
+  // Find all overrides starting with "prefix.", unless the prefix is empty.
+  // If the prefix is empty then look at all parameter overrides.
+  if (!prefix.empty() && prefix.back() != kParamSeparator) {
+    prefix += kParamSeparator;
+  }
+
+  std::unordered_set<std::string> output_names;
+  for (const auto & kv : overrides) {
+    const std::string & name = kv.first;
+    if (name.size() <= prefix.size()) {
+      // Too short, no point in checking
+      continue;
+    }
+    assert(prefix.size() < name.size());
+    // TODO(sloretz) use string::starts_with in c++20
+    if (name.rfind(prefix, 0) == 0) {  // if name starts with prefix
+      // Truncate names to the next separator
+      size_t separator_pos = name.find(kParamSeparator, prefix.size());
+      // Insert truncated name
+      output_names.insert(name.substr(0, separator_pos));
+    }
+  }
+  return output_names;
+}
+}  // namespace rclcpp

rclcpp/test/rclcpp/CMakeLists.txt

@@ -766,3 +766,8 @@ function(test_subscription_content_filter_for_rmw_implementation)
   endif()
 endfunction()
 call_for_each_rmw_implementation(test_subscription_content_filter_for_rmw_implementation)
+
+ament_add_gtest(test_list_parameter_override_prefixes test_list_parameter_override_prefixes.cpp)
+if(TARGET test_list_parameter_override_prefixes)
+  target_link_libraries(test_list_parameter_override_prefixes ${PROJECT_NAME})
+endif()

rclcpp/test/rclcpp/test_list_parameter_override_prefixes.cpp

@@ -0,0 +1,77 @@
+// Copyright 2023 Intrisnic.ai
+//
+// 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.
+
+#include <gtest/gtest.h>
+
+#include <map>
+#include <string>
+
+#include <rclcpp/list_parameter_override_prefixes.hpp>
+
+TEST(parameter, list_parameter_override_prefixes)
+{
+  const std::map<std::string, rclcpp::ParameterValue> overrides = {
+    {"foo", {}},
+    {"foo.baz", {}},
+    {"foo.bar", {}},
+    {"foo.bar.baz", {}},
+    {"foo.bar.baz.bing", {}},
+    {"foobar.baz", {}},
+    {"baz", {}}
+  };
+
+  {
+    auto matches = rclcpp::detail::list_parameter_override_prefixes(
+      overrides, "foo");
+    EXPECT_EQ(2u, matches.size());
+    EXPECT_NE(matches.end(), matches.find("foo.baz"));
+    EXPECT_NE(matches.end(), matches.find("foo.bar"));
+  }
+  {
+    auto matches = rclcpp::detail::list_parameter_override_prefixes(
+      overrides, "foo.bar");
+    EXPECT_EQ(1u, matches.size());
+    EXPECT_NE(matches.end(), matches.find("foo.bar.baz"));
+  }
+  {
+    auto matches = rclcpp::detail::list_parameter_override_prefixes(
+      overrides, "foo.bar.baz");
+    EXPECT_EQ(1u, matches.size());
+    EXPECT_NE(matches.end(), matches.find("foo.bar.baz.bing"));
+  }
+  {
+    auto matches = rclcpp::detail::list_parameter_override_prefixes(
+      overrides, "foo.baz");
+    EXPECT_EQ(0u, matches.size());
+  }
+  {
+    auto matches = rclcpp::detail::list_parameter_override_prefixes(
+      overrides, "foobar");
+    EXPECT_EQ(1u, matches.size());
+    EXPECT_NE(matches.end(), matches.find("foobar.baz"));
+  }
+  {
+    auto matches = rclcpp::detail::list_parameter_override_prefixes(
+      overrides, "dne");
+    EXPECT_EQ(0u, matches.size());
+  }
+  {
+    auto matches = rclcpp::detail::list_parameter_override_prefixes(
+      overrides, "");
+    EXPECT_EQ(3u, matches.size());
+    EXPECT_NE(matches.end(), matches.find("foo"));
+    EXPECT_NE(matches.end(), matches.find("foobar"));
+    EXPECT_NE(matches.end(), matches.find("baz"));
+  }
+}