1 files changed, 101 insertions, 0 deletions
diff --git a/third_party/libwebrtc/api/test/metrics/stdout_metrics_exporter.cc b/third_party/libwebrtc/api/test/metrics/stdout_metrics_exporter.cc
new file mode 100644
index 0000000000..22243e73e8
--- /dev/null
+++ b/third_party/libwebrtc/api/test/metrics/stdout_metrics_exporter.cc
@@ -0,0 +1,101 @@
+/*
+ *  Copyright (c) 2022 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#include "api/test/metrics/stdout_metrics_exporter.h"
+
+#include <stdio.h>
+
+#include <cmath>
+#include <string>
+
+#include "absl/types/optional.h"
+#include "api/array_view.h"
+#include "api/test/metrics/metric.h"
+#include "rtc_base/strings/string_builder.h"
+
+namespace webrtc {
+namespace test {
+namespace {
+
+// Returns positive integral part of the number.
+int64_t IntegralPart(double value) {
+  return std::lround(std::floor(std::abs(value)));
+}
+
+void AppendWithPrecision(double value,
+                         int digits_after_comma,
+                         rtc::StringBuilder& out) {
+  int64_t multiplier = std::lround(std::pow(10, digits_after_comma));
+  int64_t integral_part = IntegralPart(value);
+  double decimal_part = std::abs(value) - integral_part;
+
+  // If decimal part has leading zeros then when it will be multiplied on
+  // `multiplier`, leading zeros will be lost. To preserve them we add "1"
+  // so then leading digit will be greater than 0 and won't be removed.
+  //
+  // During conversion to the string leading digit has to be stripped.
+  //
+  // Also due to rounding it may happen that leading digit may be incremented,
+  // like with `digits_after_comma` 3 number 1.9995 will be rounded to 2. In
+  // such case this increment has to be propagated to the `integral_part`.
+  int64_t decimal_holder = std::lround((1 + decimal_part) * multiplier);
+  if (decimal_holder >= 2 * multiplier) {
+    // Rounding incremented added leading digit, so we need to transfer 1 to
+    // integral part.
+    integral_part++;
+    decimal_holder -= multiplier;
+  }
+  // Remove trailing zeros.
+  while (decimal_holder % 10 == 0) {
+    decimal_holder /= 10;
+  }
+
+  // Print serialized number to output.
+  if (value < 0) {
+    out << "-";
+  }
+  out << integral_part;
+  if (decimal_holder != 1) {
+    out << "." << std::to_string(decimal_holder).substr(1, digits_after_comma);
+  }
+}
+
+}  // namespace
+
+StdoutMetricsExporter::StdoutMetricsExporter() : output_(stdout) {}
+
+bool StdoutMetricsExporter::Export(rtc::ArrayView<const Metric> metrics) {
+  for (const Metric& metric : metrics) {
+    PrintMetric(metric);
+  }
+  return true;
+}
+
+void StdoutMetricsExporter::PrintMetric(const Metric& metric) {
+  rtc::StringBuilder value_stream;
+  value_stream << metric.test_case << " / " << metric.name << "= {mean=";
+  if (metric.stats.mean.has_value()) {
+    AppendWithPrecision(*metric.stats.mean, 8, value_stream);
+  } else {
+    value_stream << "-";
+  }
+  value_stream << ", stddev=";
+  if (metric.stats.stddev.has_value()) {
+    AppendWithPrecision(*metric.stats.stddev, 8, value_stream);
+  } else {
+    value_stream << "-";
+  }
+  value_stream << "} " << ToString(metric.unit) << " ("
+               << ToString(metric.improvement_direction) << ")";
+
+  fprintf(output_, "RESULT: %s\n", value_stream.str().c_str());
+}
+
+}  // namespace test
+}  // namespace webrtc