Add sample performance test

.gitignore

@@ -28,3 +28,4 @@
 *.app
 
 build/
+cmake-build*/

CMakeLists.txt

@@ -44,3 +44,4 @@ EXPORT(TARGETS EventBus FILE EventBusConfig.cmake)
 
 ENABLE_TESTING()
 ADD_SUBDIRECTORY(test/)
+ADD_SUBDIRECTORY(performance/)

performance/CMakeLists.txt

@@ -0,0 +1,10 @@
+# http://www.levelofindirection.com/journal/2010/12/28/unit-testing-in-c-and-objective-c-just-got-easier.html
+# Thanks for CATCH!
+
+ADD_SUBDIRECTORY(benchmark/)
+
+ADD_EXECUTABLE(EventBusPerformance
+		eventbus/EventBusPerformance.cpp
+		)
+
+TARGET_LINK_LIBRARIES(EventBusPerformance PUBLIC Dexode::EventBus benchmark)

performance/README.md

@@ -0,0 +1,31 @@
+# Performace
+
+This is maybe not perfect but can show something. All result are run using RELESE build.  
+Why?
+
+Sample DEBUG run:  
+```commandline
+Run on (8 X 3600 MHz CPU s)
+2017-08-05 12:44:53
+***WARNING*** Library was built as DEBUG. Timings may be affected.
+---------------------------------------------------------------
+Benchmark                        Time           CPU Iterations
+---------------------------------------------------------------
+checkSimpleNotification        293 ns        293 ns    2319171
+```
+
+Sample RELEASE run:  
+```commandline
+Run on (8 X 3600 MHz CPU s)
+2017-08-05 12:45:43
+---------------------------------------------------------------
+Benchmark                        Time           CPU Iterations
+---------------------------------------------------------------
+checkSimpleNotification          6 ns          6 ns  116492914
+```
+
+So below all numbers are in release.
+
+This library as you can read in main README.md was inspured by [CCNotificationCenter](https://github.com/cocos2d/cocos2d-x/blob/v2/cocos2dx/support/CCNotificationCenter.h) from cocos2d-x game engine.  
+So i want to present comparision of performance of this two. Of course this is only showcase.
+

performance/eventbus/EventBusPerformance.cpp

@@ -0,0 +1,129 @@
+//
+// Created by Dawid Drozd aka Gelldur on 05.08.17.
+//
+#include <random>
+
+#include <benchmark/benchmark.h>
+#include <eventbus/Notifier.h>
+
+namespace
+{
+
+MAKE_NOTIFICATION(SimpleNotification, int);
+
+void checkSimpleNotification(benchmark::State& state)
+{
+	Dexode::Notifier bus;
+	int sum = 0;
+	bus.listen(getNotificationSimpleNotification(), [&](int value)
+	{
+		sum += value * 2;
+	});
+
+	while (state.KeepRunning())
+	{
+		bus.notify(getNotificationSimpleNotification(), 2);
+	}
+}
+
+void check100Listeners(benchmark::State& state)
+{
+	Dexode::Notifier bus;
+	int sum = 0;
+	for (int i = 0; i < 100; ++i)
+	{
+		bus.listen(getNotificationSimpleNotification(), [&](int value)
+		{
+			sum += value * 2;
+		});
+	}
+
+	while (state.KeepRunning())
+	{
+		bus.notify(getNotificationSimpleNotification(), 2);
+	}
+}
+
+void check1kListeners(benchmark::State& state)
+{
+	Dexode::Notifier bus;
+	int sum = 0;
+	for (int i = 0; i < 1000; ++i)
+	{
+		bus.listen(getNotificationSimpleNotification(), [&](int value)
+		{
+			sum += value * 2;
+		});
+	}
+
+	while (state.KeepRunning())
+	{
+		bus.notify(getNotificationSimpleNotification(), 2);
+	}
+}
+
+void checkNNotificationsForNListeners(benchmark::State& state, const int notificationsCount, const int listenersCount)
+{
+	std::mt19937 generator(311281);
+	std::uniform_int_distribution<int> uniformDistribution(0, notificationsCount - 1);
+
+	//We generate here N different notifications
+	std::vector<Dexode::Notification<int>> notifications;
+	notifications.reserve(notificationsCount);
+	for (int i = 0; i < notificationsCount; ++i)
+	{
+		notifications.emplace_back(691283);
+	}
+
+	Dexode::Notifier bus;
+	int sum = 0;
+	//We register 1k listeners for N notifications using uniform distribution
+	for (int i = 0; i < listenersCount; ++i)
+	{
+		const auto& notification = notifications.at(uniformDistribution(generator));
+		bus.listen(notification, [&](int value)
+		{
+			benchmark::DoNotOptimize(sum += value * 2);//we use it to prevent some? optimizations
+		});
+	}
+
+	//Performance area!
+	while (state.KeepRunning())
+	{
+		//Pick random notification
+		const auto& notification = notifications.at(uniformDistribution(generator));
+		bus.notify(notification, uniformDistribution(generator));
+	}
+}
+
+void check10NotificationsFor1kListeners(benchmark::State& state)
+{
+	checkNNotificationsForNListeners(state, 10, 1000);
+}
+
+void check100NotificationsFor1kListeners(benchmark::State& state)
+{
+	checkNNotificationsForNListeners(state, 100, 1000);
+}
+
+void check1kNotificationsFor1kListeners(benchmark::State& state)
+{
+	checkNNotificationsForNListeners(state, 1000, 1000);
+}
+
+void check100NotificationsFor10kListeners(benchmark::State& state)
+{
+	checkNNotificationsForNListeners(state, 100, 10000);
+}
+
+}
+
+BENCHMARK(checkSimpleNotification);
+BENCHMARK(check100Listeners);
+BENCHMARK(check1kListeners);
+BENCHMARK(check10NotificationsFor1kListeners);
+BENCHMARK(check100NotificationsFor1kListeners);
+BENCHMARK(check1kNotificationsFor1kListeners);
+BENCHMARK(check100NotificationsFor10kListeners);
+
+BENCHMARK_MAIN();