Trace-based benchmarking via a mojo app.

apps/benchmark/measurements.cc

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "apps/benchmark/measurements.h"
+
+namespace benchmark {
+namespace {
+
+bool Match(const Event& event, const EventSpec& spec) {
+  return event.name == spec.name && event.category == spec.category;
+}
+
+}  // namespace
+
+EventSpec::EventSpec() {}
+
+EventSpec::EventSpec(std::string name, std::string category)
+    : name(name), category(category) {}
+
+EventSpec::~EventSpec() {}
+
+Measurement::Measurement() {}
+
+Measurement::Measurement(MeasurementType type,
+                         std::string target_name,
+                         std::string target_category)
+    : type(type), target_event(target_name, target_category) {}
+
+Measurement::~Measurement() {}
+
+Measurements::Measurements(std::vector<Event> events,
+                           base::TimeTicks time_origin)
+    : events_(events), time_origin_(time_origin) {}
+
+Measurements::~Measurements() {}
+
+double Measurements::Measure(const Measurement& measurement) {
+  switch (measurement.type) {
+    case MeasurementType::TIME_UNTIL:
+      return TimeUntil(measurement.target_event);
+    case MeasurementType::AVG_DURATION:
+      return AvgDuration(measurement.target_event);
+    default:
+      NOTREACHED();
+      return double();
+  }
+}
+
+double Measurements::TimeUntil(const EventSpec& event_spec) {
+  base::TimeTicks earliest;
+  bool found = false;
+  for (const Event& event : events_) {
+    if (event.category == "__metadata")
+      continue;
+
+    if (!Match(event, event_spec))
+      continue;
+
+    if (found) {
+      earliest = std::min(earliest, event.timestamp);
+    } else {
+      earliest = event.timestamp;
+      found = true;
+    }
+  }
+  if (!found)
+    return -1.0;
+  return (earliest - time_origin_).InMillisecondsF();
+}
+
+double Measurements::AvgDuration(const EventSpec& event_spec) {
+  double sum = 0.0;
+  int count = 0;
+  for (const Event& event : events_) {
+    if (event.category == "__metadata")
+      continue;
+
+    if (!Match(event, event_spec))
+      continue;
+
+    sum += event.duration.InMillisecondsF();
+    count += 1;
+  }
+
+  if (!count)
+    return -1.0;
+  return sum / count;
+}
+
+}  // namespace benchmark