Add Timing, TimingData and Timed classes for time measurement to pbd/timing.h

3 files changed, 248 insertions, 0 deletions

diff --git a/libs/pbd/pbd/timing.h b/libs/pbd/pbd/timing.h
new file mode 100644
index 0000000000..2ba9cab8ff
--- /dev/null
+++ b/libs/pbd/pbd/timing.h
@@ -0,0 +1,181 @@
+/*
+    Copyright (C) 2014 Tim Mayberry
+
+    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., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#ifndef __libpbd_timing_h__
+#define __libpbd_timing_h__
+
+#include <glib.h>
+
+#include <stdint.h>
+
+#include <string>
+#include <vector>
+
+#include "pbd/libpbd_visibility.h"
+
+namespace PBD {
+
+LIBPBD_API bool get_min_max_avg_total (const std::vector<uint64_t>& values, uint64_t& min, uint64_t& max, uint64_t& avg, uint64_t& total);
+
+LIBPBD_API std::string timing_summary (const std::vector<uint64_t>& values);
+
+/**
+ * This class allows collecting timing data using two different
+ * techniques. The first is using start() and update() and then
+ * calling elapsed() to get the elapsed time. This is useful when
+ * you want to measure the elapsed time between two different
+ * execution points. e.g
+ *
+ * timing.start();
+ * do_stuff();
+ * timing.update();
+ * cerr << "do_stuff took: "
+ *      << timing.elapsed()
+ *      << "usecs" << endl;
+ *
+ * The other is timing intervals using start() and calling
+ * get_interval() periodically to measure the time intervals
+ * between the same execution point. The difference is necessary
+ * to get the most accurate timing information when timing
+ * intervals but I didn't feel it necessary to have two separate
+ * classes.
+ */
+class LIBPBD_API Timing
+{
+public:
+
+	Timing ()
+		: m_start_val(0)
+		, m_last_val(0)
+	{ start ();}
+
+	bool valid () const {
+		return (m_start_val != 0 && m_last_val != 0);
+	}
+
+	void start () {
+		m_start_val = g_get_monotonic_time ();
+		m_last_val = 0;
+	}
+
+	void update () {
+		m_last_val = g_get_monotonic_time ();
+	}
+
+	void reset () {
+		m_start_val = m_last_val = 0;
+	}
+
+	uint64_t get_interval () {
+		uint64_t elapsed = 0;
+		update ();
+		if (valid()) {
+			elapsed = m_last_val - m_start_val;
+			m_start_val = m_last_val;
+			m_last_val = 0;
+		}
+		return elapsed;
+	}
+
+	/// Elapsed time in microseconds
+	uint64_t elapsed () const {
+		return m_last_val - m_start_val;
+	}
+
+private:
+
+	uint64_t m_start_val;
+	uint64_t m_last_val;
+
+};
+
+class LIBPBD_API TimingData
+{
+public:
+	TimingData () : m_reserve_size(256)
+	{ reset (); }
+
+	void start_timing () {
+		m_timing.start ();
+	}
+
+	void add_elapsed () {
+		m_timing.update ();
+		if (m_timing.valid()) {
+			m_elapsed_values.push_back (m_timing.elapsed());
+		}
+	}
+
+	void add_interval () {
+		uint64_t interval = m_timing.get_interval ();
+		m_elapsed_values.push_back (interval);
+	}
+
+	void reset () {
+		m_elapsed_values.clear ();
+		m_elapsed_values.reserve (m_reserve_size);
+	}
+
+	std::string summary () const
+	{ return timing_summary (m_elapsed_values); }
+
+	bool get_min_max_avg_total (uint64_t& min,
+	                            uint64_t& max,
+	                            uint64_t& avg,
+	                            uint64_t& total) const
+	{ return PBD::get_min_max_avg_total (m_elapsed_values, min, max, avg, total); }
+
+	void reserve (uint32_t reserve_size)
+	{ m_reserve_size = reserve_size; reset (); }
+
+	uint32_t size () const
+	{ return m_elapsed_values.size(); }
+
+private:
+
+	Timing m_timing;
+
+	uint32_t m_reserve_size;
+
+	std::vector<uint64_t> m_elapsed_values;
+};
+
+class LIBPBD_API Timed
+{
+public:
+	Timed (TimingData& data)
+		: m_data(data)
+	{
+		m_data.start_timing ();
+	}
+
+	~Timed ()
+	{
+		m_data.add_elapsed ();
+	}
+
+private:
+
+	TimingData& m_data;
+
+};
+
+} // namespace PBD
+
+#endif // __libpbd_timing_h__
diff --git a/libs/pbd/timing.cc b/libs/pbd/timing.cc
new file mode 100644
index 0000000000..b811c09f96
--- /dev/null
+++ b/libs/pbd/timing.cc
@@ -0,0 +1,66 @@
+/*
+    Copyright (C) 2014 Tim Mayberry
+
+    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., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include "pbd/timing.h"
+
+#include <sstream>
+#include <limits>
+
+namespace PBD {
+
+bool
+get_min_max_avg_total (const std::vector<uint64_t>& values, uint64_t& min, uint64_t& max, uint64_t& avg, uint64_t& total)
+{
+	if (values.empty()) {
+		return false;
+	}
+
+	total = 0;
+	min = std::numeric_limits<uint64_t>::max();
+	max = 0; avg = 0;
+
+	for (std::vector<uint64_t>::const_iterator ci = values.begin(); ci != values.end(); ++ci) {
+		total += *ci;
+		min = std::min (min, *ci);
+		max = std::max (max, *ci);
+	}
+
+	avg = total / values.size();
+	return true;
+}
+
+std::string
+timing_summary (const std::vector<uint64_t>& values)
+{
+	std::ostringstream oss;
+
+	uint64_t min, max, avg, total;
+
+	if (get_min_max_avg_total (values, min, max, avg, total)) {
+		oss << "Count: " << values.size()
+		    << " Min: " << min
+		    << " Max: " << max
+		    << " Avg: " << avg
+		    << " Total: " << total
+		    << std::endl;
+	}
+	return oss.str();
+}
+
+} // namespace PBD
diff --git a/libs/pbd/wscript b/libs/pbd/wscript
index f6ea66f504..1535f6446e 100644
--- a/libs/pbd/wscript
+++ b/libs/pbd/wscript
@@ -75,6 +75,7 @@ libpbd_sources = [
     'strsplit.cc',
     'system_exec.cc',
     'textreceiver.cc',
+    'timing.cc',
     'transmitter.cc',
     'undo.cc',
     'uuid.cc',