BLI: add ScopedTimer

This adds a simple timer that can be used for performance measurements in C++.
More sophisticated timers are possible (e.g. one that takes averages, logs the results, ...).
However, I found that this simple timer is good enough for 99% of my use cases.

To use it just write `SCOPED_TIMER("my timer name");` or more commonly `SCOPED_TIMER(__func__);`
into some scope.

Reviewers: sergey

Differential Revision: https://developer.blender.org/D7491

1 files changed, 36 insertions, 0 deletions

diff --git a/source/blender/blenlib/intern/timeit.cc b/source/blender/blenlib/intern/timeit.cc
new file mode 100644
index 00000000000..bab8fd81746
--- /dev/null
+++ b/source/blender/blenlib/intern/timeit.cc
@@ -0,0 +1,36 @@
+/*
+ * 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 "BLI_timeit.hh"
+
+namespace BLI {
+namespace Timeit {
+
+void print_duration(Nanoseconds duration)
+{
+  if (duration < std::chrono::microseconds(100)) {
+    std::cout << duration.count() << " ns";
+  }
+  else if (duration < std::chrono::seconds(5)) {
+    std::cout << duration.count() / 1.0e6 << " ms";
+  }
+  else {
+    std::cout << duration.count() / 1.0e9 << " s";
+  }
+}
+
+}  // namespace Timeit
+}  // namespace BLI