benchmark prival from string (#379)

Add a benchmark test for stumpless_prival_from_string.

This fixes #378 which can be referenced for more information.

CMakeLists.txt

@@ -1014,7 +1014,11 @@ add_custom_target(examples
 
 # performance tests
 add_performance_test(element
-  SOURCES test/performance/element.cpp
+SOURCES test/performance/element.cpp
+)
+
+add_performance_test(priority
+SOURCES test/performance/priority.cpp
 )
 
 add_performance_test(entry

test/performance/priority.cpp

@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: Apache-2.0
+
+/*
+ * Copyright 2020-2022 Joel E. Anderson
+ *
+ * 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 <benchmark/benchmark.h>
+#include <stumpless.h>
+#include "test/helper/memory_counter.hpp"
+#include <string>
+
+NEW_MEMORY_COUNTER( prival_from_string )
+
+static void PrivalFromString(benchmark::State& state) {
+  // Create a list of priorities.
+  std::vector<std::string> priority_list = {"191", "user.emerg", "uucp.err", "local7.debug"};
+
+  INIT_MEMORY_COUNTER( prival_from_string );
+
+  // Measure the time it takes to call the function.
+  for (auto _ : state) {
+    for (const auto& priority : priority_list) {
+      int result = stumpless_prival_from_string(priority.c_str());
+      if ( result< 0) {
+        state.SkipWithError("could not get the prival from the string");
+      }
+    }
+  }
+  SET_STATE_COUNTERS( state, prival_from_string );
+}
+
+BENCHMARK(PrivalFromString);