Add functions to convert between qos policy values and strings

rmw/CMakeLists.txt

@@ -32,6 +32,7 @@ set(rmw_sources
   "src/message_sequence.c"
   "src/names_and_types.c"
   "src/publisher_options.c"
+  "src/qos_string_conversions.c"
   "src/sanity_checks.c"
   "src/security_options.c"
   "src/subscription_options.c"

rmw/include/rmw/qos_string_conversions.h

@@ -0,0 +1,128 @@
+// 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.
+
+#ifndef RMW__QOS_STRING_CONVERSIONS_H_
+#define RMW__QOS_STRING_CONVERSIONS_H_
+
+#include "rmw/types.h"
+#include "rmw/visibility_control.h"
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif
+
+/// Return a string representing the policy value.
+/**
+ * Returns `NULL` when `value` is `RMW_QOS_POLICY_*_UNKNOWN` or an undefined enum value.
+ *
+ * The stringified version of the policy value can be obtained doing the follwing conversion:
+ * RMW_QOS_POLICY_<POLICY_KIND>_<POLICY_VALUE> -> lower_case(<POLICY_VALUE>)
+ *
+ * For example, the stringified version of `RMW_QOS_POLICY_LIVELINESS_MANUAL_BY_TOPIC` is
+ * "manual_by_topic" and `RMW_QOS_POLICY_RELIABILITY_BEST_EFFORT` is "best_effort".
+ *
+ * <hr>
+ * Attribute          | Adherence
+ * ------------------ | -------------
+ * Allocates Memory   | No
+ * Thread-Safe        | Yes
+ * Uses Atomics       | No
+ * Lock-Free          | Yes
+ *
+ * \param[in] value qos policy value to be stringified.
+ * \return a null terminated string representing the policy value, or
+ * \return `NULL` if value is `RMW_QOS_POLICY_*_UNKNOWN` or an undefined enum value.
+ */
+RMW_PUBLIC
+const char *
+rmw_qos_durability_policy_to_str(enum rmw_qos_durability_policy_t value);
+
+/// Return a string representing the policy value.
+/**
+ * See \ref rmw_qos_durability_policy_to_str() for more details.
+ */
+RMW_PUBLIC
+const char *
+rmw_qos_history_policy_to_str(enum rmw_qos_history_policy_t value);
+
+/// Return a string representing the policy value.
+/**
+ * See \ref rmw_qos_durability_policy_to_str() for more details.
+ */
+RMW_PUBLIC
+const char *
+rmw_qos_liveliness_policy_to_str(enum rmw_qos_liveliness_policy_t value);
+
+/// Return a string representing the policy value.
+/**
+ * See \ref rmw_qos_durability_policy_to_str() for more details.
+ */
+RMW_PUBLIC
+const char *
+rmw_qos_reliability_policy_to_str(enum rmw_qos_reliability_policy_t value);
+
+/// Return a enum value based on the provided string.
+/**
+ * Returns the enum value based on the provided string, or
+ * `RMW_QOS_POLICY_*_UNKNOWN` when the provided string is unexpected.
+ *
+ * How policy values are stringified is explained in \ref rmw_qos_durability_policy_to_str.
+ *
+ * <hr>
+ * Attribute          | Adherence
+ * ------------------ | -------------
+ * Allocates Memory   | No
+ * Thread-Safe        | Yes
+ * Uses Atomics       | No
+ * Lock-Free          | Yes
+ *
+ * \param[in] str string identifying a qos policy value.
+ * \return the policy value represented by the string, or
+ * \return `RMW_QOS_POLICY_*_UNKNOWN` if the string doesn't represent any value.
+ */
+RMW_PUBLIC
+enum rmw_qos_durability_policy_t
+rmw_qos_durability_policy_from_str(const char * str);
+
+/// Return a enum value based on the provided string.
+/**
+ * See \ref rmw_qos_durability_policy_from_str() for more details.
+ */
+RMW_PUBLIC
+enum rmw_qos_history_policy_t
+rmw_qos_history_policy_from_str(const char * str);
+
+/// Return a enum value based on the provided string.
+/**
+ * See \ref rmw_qos_durability_policy_from_str() for more details.
+ */
+RMW_PUBLIC
+enum rmw_qos_liveliness_policy_t
+rmw_qos_liveliness_policy_from_str(const char * str);
+
+
+/// Return a enum value based on the provided string.
+/**
+ * See \ref rmw_qos_durability_policy_from_str() for more details.
+ */
+RMW_PUBLIC
+enum rmw_qos_reliability_policy_t
+rmw_qos_reliability_policy_from_str(const char * str);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // RMW__QOS_STRING_CONVERSIONS_H_

rmw/src/qos_string_conversions.c

@@ -0,0 +1,142 @@
+// 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.
+
+#include "rmw/qos_string_conversions.h"
+
+const char *
+rmw_qos_durability_policy_to_str(enum rmw_qos_durability_policy_t value)
+{
+  switch (value) {
+    case RMW_QOS_POLICY_DURABILITY_SYSTEM_DEFAULT:
+      return "system_default";
+    case RMW_QOS_POLICY_DURABILITY_TRANSIENT_LOCAL:
+      return "transient_local";
+    case RMW_QOS_POLICY_DURABILITY_VOLATILE:
+      return "volatile";
+    case RMW_QOS_POLICY_DURABILITY_UNKNOWN:  // fallthrough
+    default:
+      return NULL;
+  }
+}
+
+const char *
+rmw_qos_history_policy_to_str(enum rmw_qos_history_policy_t value)
+{
+  switch (value) {
+    case RMW_QOS_POLICY_HISTORY_SYSTEM_DEFAULT:
+      return "system_default";
+    case RMW_QOS_POLICY_HISTORY_KEEP_LAST:
+      return "keep_last";
+    case RMW_QOS_POLICY_HISTORY_KEEP_ALL:
+      return "keep_all";
+    case RMW_QOS_POLICY_HISTORY_UNKNOWN:  // fallthrough
+    default:
+      return NULL;
+  }
+}
+
+const char *
+rmw_qos_liveliness_policy_to_str(enum rmw_qos_liveliness_policy_t value)
+{
+  switch (value) {
+    case RMW_QOS_POLICY_LIVELINESS_SYSTEM_DEFAULT:
+      return "system_default";
+    case RMW_QOS_POLICY_LIVELINESS_AUTOMATIC:
+      return "automatic";
+    case RMW_QOS_POLICY_LIVELINESS_MANUAL_BY_TOPIC:
+      return "manual_by_topic";
+    case RMW_QOS_POLICY_LIVELINESS_UNKNOWN:  // fallthrough
+    default:
+      return NULL;
+  }
+}
+
+const char *
+rmw_qos_reliability_policy_to_str(enum rmw_qos_reliability_policy_t value)
+{
+  switch (value) {
+    case RMW_QOS_POLICY_RELIABILITY_SYSTEM_DEFAULT:
+      return "system_default";
+    case RMW_QOS_POLICY_RELIABILITY_RELIABLE:
+      return "reliable";
+    case RMW_QOS_POLICY_RELIABILITY_BEST_EFFORT:
+      return "best_effort";
+    case RMW_QOS_POLICY_RELIABILITY_UNKNOWN:  // fallthrough
+    default:
+      return NULL;
+  }
+}
+
+#define RMW_QOS_STREQ_WITH_LITERAL(string_literal, string) \
+  (0 == strncmp(string_literal, str, sizeof(string_literal)))
+
+enum rmw_qos_durability_policy_t
+rmw_qos_durability_policy_from_str(const char * str)
+{
+  if (RMW_QOS_STREQ_WITH_LITERAL("system_default", str)) {
+    return RMW_QOS_POLICY_DURABILITY_SYSTEM_DEFAULT;
+  }
+  if (RMW_QOS_STREQ_WITH_LITERAL("transient_local", str)) {
+    return RMW_QOS_POLICY_DURABILITY_TRANSIENT_LOCAL;
+  }
+  if (RMW_QOS_STREQ_WITH_LITERAL("volatile", str)) {
+    return RMW_QOS_POLICY_DURABILITY_VOLATILE;
+  }
+  return RMW_QOS_POLICY_DURABILITY_UNKNOWN;
+}
+
+enum rmw_qos_history_policy_t
+rmw_qos_history_policy_from_str(const char * str)
+{
+  if (RMW_QOS_STREQ_WITH_LITERAL("system_default", str)) {
+    return RMW_QOS_POLICY_HISTORY_SYSTEM_DEFAULT;
+  }
+  if (RMW_QOS_STREQ_WITH_LITERAL("keep_last", str)) {
+    return RMW_QOS_POLICY_HISTORY_KEEP_LAST;
+  }
+  if (RMW_QOS_STREQ_WITH_LITERAL("keep_all", str)) {
+    return RMW_QOS_POLICY_HISTORY_KEEP_ALL;
+  }
+  return RMW_QOS_POLICY_HISTORY_UNKNOWN;
+}
+
+enum rmw_qos_liveliness_policy_t
+rmw_qos_liveliness_policy_from_str(const char * str)
+{
+  if (RMW_QOS_STREQ_WITH_LITERAL("system_default", str)) {
+    return RMW_QOS_POLICY_LIVELINESS_SYSTEM_DEFAULT;
+  }
+  if (RMW_QOS_STREQ_WITH_LITERAL("automatic", str)) {
+    return RMW_QOS_POLICY_LIVELINESS_AUTOMATIC;
+  }
+  if (RMW_QOS_STREQ_WITH_LITERAL("manual_by_topic", str)) {
+    return RMW_QOS_POLICY_LIVELINESS_MANUAL_BY_TOPIC;
+  }
+  return RMW_QOS_POLICY_LIVELINESS_UNKNOWN;
+}
+
+enum rmw_qos_reliability_policy_t
+rmw_qos_reliability_policy_from_str(const char * str)
+{
+  if (RMW_QOS_STREQ_WITH_LITERAL("system_default", str)) {
+    return RMW_QOS_POLICY_RELIABILITY_SYSTEM_DEFAULT;
+  }
+  if (RMW_QOS_STREQ_WITH_LITERAL("reliable", str)) {
+    return RMW_QOS_POLICY_RELIABILITY_RELIABLE;
+  }
+  if (RMW_QOS_STREQ_WITH_LITERAL("best_effort", str)) {
+    return RMW_QOS_POLICY_RELIABILITY_BEST_EFFORT;
+  }
+  return RMW_QOS_POLICY_RELIABILITY_UNKNOWN;
+}

rmw/test/CMakeLists.txt

@@ -75,6 +75,15 @@ if(TARGET test_publisher_options)
   target_link_libraries(test_publisher_options ${PROJECT_NAME})
 endif()
 
+ament_add_gtest(test_qos_string_conversions
+test_qos_string_conversions.cpp
+  # Append the directory of librmw so it is found at test time.
+  APPEND_LIBRARY_DIRS "$<TARGET_FILE_DIR:${PROJECT_NAME}>"
+)
+if(TARGET test_qos_string_conversions)
+  target_link_libraries(test_qos_string_conversions ${PROJECT_NAME})
+endif()
+
 ament_add_gmock(test_sanity_checks
   test_sanity_checks.cpp
   # Append the directory of librmw so it is found at test time.

rmw/test/test_qos_string_conversions.cpp

@@ -0,0 +1,55 @@
+// 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.
+
+#include <gtest/gtest.h>
+
+#include "rmw/qos_string_conversions.h"
+#include "rmw/types.h"
+
+// Converts to string and back to the policy value, check that it's the same
+#define TEST_QOS_POLICY_VALUE_STRINGIFY(kind, value) \
+  do { \
+    EXPECT_EQ( \
+      value, rmw_qos_ ## kind ## _policy_from_str(rmw_qos_ ## kind ## _policy_to_str(value))); \
+  } while (0)
+
+// Check unrecognized string as input of from_str, check UNKNOWN as input of to_str.
+#define TEST_QOS_POLICY_STRINGIFY_CORNER_CASES(kind, kind_upper) \
+  do { \
+    EXPECT_EQ( \
+      NULL, rmw_qos_ ## kind ## _policy_to_str(RMW_QOS_POLICY_ ## kind_upper ## _UNKNOWN)); \
+    EXPECT_EQ( \
+      RMW_QOS_POLICY_ ## kind_upper ## _UNKNOWN, \
+      rmw_qos_ ## kind ## _policy_from_str("this could never be a stringified policy value")); \
+  } while (0)
+
+TEST(test_qos_policy_stringify, test_normal_use) {
+  TEST_QOS_POLICY_VALUE_STRINGIFY(durability, RMW_QOS_POLICY_DURABILITY_SYSTEM_DEFAULT);
+  TEST_QOS_POLICY_VALUE_STRINGIFY(durability, RMW_QOS_POLICY_DURABILITY_TRANSIENT_LOCAL);
+  TEST_QOS_POLICY_VALUE_STRINGIFY(durability, RMW_QOS_POLICY_DURABILITY_VOLATILE);
+  TEST_QOS_POLICY_VALUE_STRINGIFY(history, RMW_QOS_POLICY_HISTORY_KEEP_LAST);
+  TEST_QOS_POLICY_VALUE_STRINGIFY(history, RMW_QOS_POLICY_HISTORY_KEEP_ALL);
+  TEST_QOS_POLICY_VALUE_STRINGIFY(history, RMW_QOS_POLICY_HISTORY_SYSTEM_DEFAULT);
+  TEST_QOS_POLICY_VALUE_STRINGIFY(liveliness, RMW_QOS_POLICY_LIVELINESS_AUTOMATIC);
+  TEST_QOS_POLICY_VALUE_STRINGIFY(liveliness, RMW_QOS_POLICY_LIVELINESS_MANUAL_BY_TOPIC);
+  TEST_QOS_POLICY_VALUE_STRINGIFY(liveliness, RMW_QOS_POLICY_LIVELINESS_SYSTEM_DEFAULT);
+  TEST_QOS_POLICY_VALUE_STRINGIFY(reliability, RMW_QOS_POLICY_RELIABILITY_BEST_EFFORT);
+  TEST_QOS_POLICY_VALUE_STRINGIFY(reliability, RMW_QOS_POLICY_RELIABILITY_RELIABLE);
+  TEST_QOS_POLICY_VALUE_STRINGIFY(reliability, RMW_QOS_POLICY_RELIABILITY_SYSTEM_DEFAULT);
+
+  TEST_QOS_POLICY_STRINGIFY_CORNER_CASES(durability, DURABILITY);
+  TEST_QOS_POLICY_STRINGIFY_CORNER_CASES(history, HISTORY);
+  TEST_QOS_POLICY_STRINGIFY_CORNER_CASES(liveliness, LIVELINESS);
+  TEST_QOS_POLICY_STRINGIFY_CORNER_CASES(reliability, RELIABILITY);
+}