Add SubscriberTopicStatisticsNode and tests (#112)

* Add subscriber_topic_statistics class and tests

Signed-off-by: Prajakta Gokhale <prajaktg@amazon.com>

* Rebase on changes in interfaces, address feedback

Signed-off-by: Prajakta Gokhale <prajaktg@amazon.com>

* Fix unit test and try to increase coverage

Signed-off-by: Prajakta Gokhale <prajaktg@amazon.com>

* Address review feedback

Signed-off-by: Prajakta Gokhale <prajaktg@amazon.com>

* Fix incorrect handling of publish timer and review comments

Signed-off-by: Prajakta Gokhale <prajaktg@amazon.com>

* Resolve conflicts

Signed-off-by: Prajakta Gokhale <prajaktg@amazon.com>

* New utility header and more review comments

Signed-off-by: Prajakta Gokhale <prajaktg@amazon.com>

libstatistics_collector/include/libstatistics_collector/topic_statistics_collector/constants.hpp

@@ -27,6 +27,9 @@ namespace topic_statistics_constants
 constexpr const char kMsgAgeStatName[] = "message_age";
 constexpr const char kMsgPeriodStatName[] = "message_period";
 constexpr const char kMillisecondUnitName[] = "ms";
+
+constexpr const char kCollectStatsTopicNameParam[] = "collect_topic_name";
+constexpr const char kPublishStatsTopicNameParam[] = "publish_topic_name";
 }  // namespace topic_statistics_constants
 
 }  // namespace topic_statistics_collector

system_metrics_collector/CMakeLists.txt

@@ -127,6 +127,11 @@ if(BUILD_TESTING)
           test/system_metrics_collector/test_utilities.cpp)
   target_link_libraries(test_utilities system_metrics_collector)
   ament_target_dependencies(test_utilities rclcpp)
+
+  ament_add_gtest(test_subscriber_topic_statistics
+          test/topic_statistics_collector/test_subscriber_topic_statistics.cpp)
+  target_link_libraries(test_subscriber_topic_statistics system_metrics_collector)
+  ament_target_dependencies(test_subscriber_topic_statistics rcl rclcpp sensor_msgs)
 endif()
 
 # Install launch files

system_metrics_collector/package.xml

@@ -27,6 +27,7 @@
   <test_depend>ament_lint_common</test_depend>
   <test_depend>class_loader</test_depend>
   <test_depend>lifecycle_msgs</test_depend>
+  <test_depend>sensor_msgs</test_depend>
 
   <!--Required for e2e test file-->
   <test_depend>python3-retrying</test_depend>

system_metrics_collector/src/topic_statistics_collector/parameter_utils.hpp

@@ -0,0 +1,90 @@
+// Copyright 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// 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 TOPIC_STATISTICS_COLLECTOR__PARAMETER_UTILS_HPP_
+#define TOPIC_STATISTICS_COLLECTOR__PARAMETER_UTILS_HPP_
+
+#include <limits>
+#include <string>
+
+#include "rcpputils/asserts.hpp"
+
+namespace topic_statistics_collector
+{
+/**
+ * Build a positive integer range to use in parameter descriptors.
+ *
+ * @return a positive integer range with specififies start, end and step values
+ */
+static rcl_interfaces::msg::IntegerRange BuildIntegerRange(
+  int64_t from,
+  int64_t to,
+  uint64_t step)
+{
+  rcl_interfaces::msg::IntegerRange range;
+  range.from_value = from;
+  range.to_value = to;
+  range.step = step;
+
+  return range;
+}
+
+/**
+ * Build a parameter description for period node parameters.
+ *
+ * @return a read-only integer range topic descriptor
+ */
+static rcl_interfaces::msg::ParameterDescriptor BuildPeriodParameterDescriptor(
+  const std::string & description)
+{
+  const auto range = BuildIntegerRange(
+    1,
+    std::numeric_limits<decltype(rcl_interfaces::msg::IntegerRange::to_value)>::max(),
+    1
+  );
+
+  rcl_interfaces::msg::ParameterDescriptor period_descriptor;
+  period_descriptor.read_only = true;
+  period_descriptor.integer_range.push_back(range);
+  period_descriptor.description = description;
+
+  return period_descriptor;
+}
+
+/**
+ * Build a parameter description for string node parameters.
+ *
+ * @return a read-only topic descriptor
+ */
+static rcl_interfaces::msg::ParameterDescriptor BuildTopicParameterDescriptor(
+  const std::string & description)
+{
+  rcl_interfaces::msg::ParameterDescriptor topic_descriptor;
+  topic_descriptor.description = description;
+  topic_descriptor.read_only = true;
+
+  return topic_descriptor;
+}
+
+/**
+ * Validate the values assigned to string node parameters.
+ *
+ * @throws std::invalid_argument if the parameter value is empty
+ */
+static void ValidateStringParam(const std::string & name, const std::string & value)
+{
+  rcpputils::require_true(!value.empty(), name + " node parameter cannot be empty");
+}
+}  // namespace topic_statistics_collector
+#endif  // TOPIC_STATISTICS_COLLECTOR__PARAMETER_UTILS_HPP_