util-profiler: Easy to use profiling helper

CMakeLists.txt

@@ -347,6 +347,8 @@ list(APPEND PROJECT_PRIVATE_SOURCE
 	"source/utility.hpp"
 	"source/utility.cpp"
 	"source/util-event.hpp"
+	"source/util-profiler.cpp"
+	"source/util-profiler.hpp"
 	"source/util-threadpool.cpp"
 	"source/util-threadpool.hpp"
 

source/util-profiler.cpp

@@ -0,0 +1,170 @@
+/*
+ * Modern effects for a modern Streamer
+ * Copyright (C) 2020 Michael Fabian Dirks
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+#include "util-profiler.hpp"
+#include <iterator>
+
+util::profiler::profiler() {}
+
+util::profiler::~profiler() {}
+
+std::shared_ptr<util::profiler::instance> util::profiler::track()
+{
+	return std::make_shared<util::profiler::instance>(shared_from_this());
+}
+
+void util::profiler::track(std::chrono::nanoseconds duration)
+{
+	std::unique_lock<std::mutex> ul(_timings_lock);
+	auto                         itr = _timings.find(duration);
+	if (itr == _timings.end()) {
+		_timings.insert({duration, 1});
+	} else {
+		itr->second++;
+	}
+}
+
+uint64_t util::profiler::count()
+{
+	uint64_t count = 0;
+
+	std::map<std::chrono::nanoseconds, size_t> copy_timings;
+	{
+		std::unique_lock<std::mutex> ul(_timings_lock);
+		copy(_timings.begin(), _timings.end(), std::inserter(copy_timings, copy_timings.end()));
+	}
+
+	for (auto kv : copy_timings) {
+		count += kv.second;
+	}
+
+	return count;
+}
+
+std::chrono::nanoseconds util::profiler::total_duration()
+{
+	std::chrono::nanoseconds duration{0};
+
+	std::map<std::chrono::nanoseconds, size_t> copy_timings;
+	{
+		std::unique_lock<std::mutex> ul(_timings_lock);
+		copy(_timings.begin(), _timings.end(), std::inserter(copy_timings, copy_timings.end()));
+	}
+
+	for (auto kv : copy_timings) {
+		duration += kv.first * kv.second;
+	}
+
+	return duration;
+}
+
+double_t util::profiler::average_duration()
+{
+	std::chrono::nanoseconds duration{0};
+	uint64_t                 count = 0;
+
+	std::map<std::chrono::nanoseconds, size_t> copy_timings;
+	{
+		std::unique_lock<std::mutex> ul(_timings_lock);
+		copy(_timings.begin(), _timings.end(), std::inserter(copy_timings, copy_timings.end()));
+	}
+
+	for (auto kv : copy_timings) {
+		duration += kv.first * kv.second;
+		count += kv.second;
+	}
+
+	return double_t(duration.count()) / double_t(count);
+}
+
+template<typename T>
+inline bool is_equal(T a, T b, T c)
+{
+	return (a == b) || ((a >= (b - c)) && (a <= (b + c)));
+}
+
+std::chrono::nanoseconds util::profiler::percentile(double_t percentile, bool by_time)
+{
+	uint64_t calls = count();
+
+	std::map<std::chrono::nanoseconds, size_t> copy_timings;
+	{
+		std::unique_lock<std::mutex> ul(_timings_lock);
+		copy(_timings.begin(), _timings.end(), inserter(copy_timings, copy_timings.end()));
+	}
+	if (by_time) { // Return by time percentile.
+		// Find largest and smallest time.
+		std::chrono::nanoseconds smallest = copy_timings.begin()->first;
+		std::chrono::nanoseconds largest  = copy_timings.rbegin()->first;
+
+		std::chrono::nanoseconds variance = largest - smallest;
+		std::chrono::nanoseconds threshold =
+			std::chrono::nanoseconds(smallest.count() + int64_t(variance.count() * percentile));
+
+		for (auto kv : copy_timings) {
+			double_t kv_pct = double_t((kv.first - smallest).count()) / double_t(variance.count());
+			if (is_equal(kv_pct, percentile, 0.00005) || (kv_pct > percentile)) {
+				return std::chrono::nanoseconds(kv.first);
+			}
+		}
+	} else { // Return by call percentile.
+		if (percentile == 0.0) {
+			return copy_timings.begin()->first;
+		}
+
+		uint64_t accu_calls_now = 0;
+		for (auto kv : copy_timings) {
+			uint64_t accu_calls_last = accu_calls_now;
+			accu_calls_now += kv.second;
+
+			double_t percentile_last = double_t(accu_calls_last) / double_t(calls);
+			double_t percentile_now  = double_t(accu_calls_now) / double_t(calls);
+
+			if (is_equal(percentile, percentile_now, 0.0005)
+				|| ((percentile_last < percentile) && (percentile_now > percentile))) {
+				return std::chrono::nanoseconds(kv.first);
+			}
+		}
+	}
+
+	return std::chrono::nanoseconds(-1);
+}
+
+util::profiler::instance::instance(std::shared_ptr<util::profiler> parent)
+	: _parent(parent), _start(std::chrono::high_resolution_clock::now())
+{}
+
+util::profiler::instance::~instance()
+{
+	auto end = std::chrono::high_resolution_clock::now();
+	auto dur = end - _start;
+	if (_parent) {
+		_parent->track(dur);
+	}
+}
+
+void util::profiler::instance::cancel()
+{
+	_parent.reset();
+}
+
+void util::profiler::instance::reparent(std::shared_ptr<util::profiler> parent)
+{
+	parent = parent;
+}

source/util-profiler.hpp

@@ -0,0 +1,70 @@
+/*
+ * Modern effects for a modern Streamer
+ * Copyright (C) 2020 Michael Fabian Dirks
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+#include <chrono>
+#include <cstddef>
+#include <map>
+#include <memory>
+#include <mutex>
+
+namespace util {
+	class profiler : public std::enable_shared_from_this<util::profiler> {
+		std::map<std::chrono::nanoseconds, size_t> _timings;
+		std::mutex                                 _timings_lock;
+
+		public:
+		class instance {
+			std::shared_ptr<profiler>                      _parent;
+			std::chrono::high_resolution_clock::time_point _start;
+
+			public:
+			instance(std::shared_ptr<profiler> parent);
+
+			~instance();
+
+			void cancel();
+
+			void reparent(std::shared_ptr<profiler> parent);
+		};
+
+		private:
+		profiler();
+
+		public:
+		~profiler();
+
+		std::shared_ptr<class util::profiler::instance> track();
+
+		void track(std::chrono::nanoseconds duration);
+
+		std::uint64_t count();
+
+		std::chrono::nanoseconds total_duration();
+
+		double_t average_duration();
+
+		std::chrono::nanoseconds percentile(double_t percentile, bool by_time = false);
+
+		public:
+		static std::shared_ptr<util::profiler> create()
+		{
+			return std::shared_ptr<util::profiler>{new profiler()};
+		}
+	};
+} // namespace util