ostream metrics example (#1312)

examples/common/metrics_foo_library/BUILD

@@ -0,0 +1,17 @@
+package(default_visibility = ["//visibility:public"])
+
+cc_library(
+    name = "common_metrics_foo_library",
+    srcs = [
+        "foo_library.cc",
+    ],
+    hdrs = [
+        "foo_library.h",
+    ],
+    defines = ["BAZEL_BUILD"],
+    deps = [
+        "//api",
+        "//sdk:headers",
+        "//sdk/src/metrics",
+    ],
+)

examples/common/metrics_foo_library/foo_library.cc

@@ -0,0 +1,25 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#ifndef ENABLE_METRICS_PREVIEW
+#  include <chrono>
+#  include <thread>
+#  include "opentelemetry/metrics/provider.h"
+
+namespace nostd       = opentelemetry::nostd;
+namespace metrics_api = opentelemetry::metrics;
+
+void foo_library(const std::string &name)
+{
+  // Get the Meter from the MeterProvider
+  auto provider                               = metrics_api::Provider::GetMeterProvider();
+  nostd::shared_ptr<metrics_api::Meter> meter = provider->GetMeter(name, "1.2.0");
+  auto double_counter                         = meter->CreateDoubleCounter(name);
+  double_counter->Add(28.5);
+  std::this_thread::sleep_for(std::chrono::milliseconds(500));
+  double_counter->Add(3.14);
+  std::this_thread::sleep_for(std::chrono::milliseconds(500));
+  double_counter->Add(23.5);
+  std::this_thread::sleep_for(std::chrono::milliseconds(5000));
+}
+#endif

examples/common/metrics_foo_library/foo_library.h

@@ -0,0 +1,9 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+#ifndef ENABLE_METRICS_PREVIEW
+#  include <string>
+
+void foo_library(const std::string &name);
+#endif

examples/metrics_simple/BUILD

@@ -11,3 +11,18 @@ cc_binary(
         "//sdk/src/_metrics:metrics_deprecated",
     ],
 )
+
+cc_binary(
+    name = "metrics_ostream_example",
+    srcs = [
+        "metrics_ostream.cc",
+    ],
+    linkopts = ["-pthread"],
+    tags = ["ostream"],
+    deps = [
+        "//api",
+        "//examples/common/metrics_foo_library:common_metrics_foo_library",
+        "//exporters/ostream:ostream_metric_exporter",
+        "//sdk/src/metrics",
+    ],
+)

examples/metrics_simple/metrics_ostream.cc

@@ -0,0 +1,65 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#ifndef ENABLE_METRICS_PREVIEW
+#  include <memory>
+#  include "opentelemetry/exporters/ostream/metric_exporter.h"
+#  include "opentelemetry/metrics/provider.h"
+#  include "opentelemetry/sdk/metrics/aggregation/default_aggregation.h"
+#  include "opentelemetry/sdk/metrics/aggregation/histogram_aggregation.h"
+#  include "opentelemetry/sdk/metrics/export/periodic_exporting_metric_reader.h"
+#  include "opentelemetry/sdk/metrics/meter.h"
+#  include "opentelemetry/sdk/metrics/meter_provider.h"
+
+#  ifdef BAZEL_BUILD
+#    include "examples/common/metrics_foo_library/foo_library.h"
+#  else
+#    include "metrics_foo_library/foo_library.h"
+#  endif
+
+namespace metric_sdk      = opentelemetry::sdk::metrics;
+namespace nostd           = opentelemetry::nostd;
+namespace common          = opentelemetry::common;
+namespace exportermetrics = opentelemetry::exporter::metrics;
+namespace metrics_api     = opentelemetry::metrics;
+
+namespace
+{
+
+void initMetrics(const std::string &name)
+{
+  std::unique_ptr<metric_sdk::MetricExporter> exporter{new exportermetrics::OStreamMetricExporter};
+  std::vector<std::unique_ptr<metric_sdk::MetricExporter>> exporters;
+
+  std::string version{"1.2.0"};
+  std::string schema{"https://opentelemetry.io/schemas/1.2.0"};
+
+  // Initialize and set the global MeterProvider
+  metric_sdk::PeriodicExportingMetricReaderOptions options;
+  options.export_interval_millis = std::chrono::milliseconds(1000);
+  options.export_timeout_millis  = std::chrono::milliseconds(500);
+  std::unique_ptr<metric_sdk::MetricReader> reader{
+      new metric_sdk::PeriodicExportingMetricReader(std::move(exporter), options)};
+  auto provider = std::shared_ptr<metrics_api::MeterProvider>(
+      new metric_sdk::MeterProvider(std::move(exporters)));
+  auto p = std::static_pointer_cast<metric_sdk::MeterProvider>(provider);
+  p->AddMetricReader(std::move(reader));
+  std::unique_ptr<metric_sdk::InstrumentSelector> instrument_selector{
+      new metric_sdk::InstrumentSelector(metric_sdk::InstrumentType::kCounter, name)};
+  std::unique_ptr<metric_sdk::MeterSelector> meter_selector{
+      new metric_sdk::MeterSelector(name, version, schema)};
+  std::unique_ptr<metric_sdk::View> view{
+      new metric_sdk::View{name, "description", metric_sdk::AggregationType::kSum}};
+  p->AddView(std::move(instrument_selector), std::move(meter_selector), std::move(view));
+  metrics_api::Provider::SetMeterProvider(provider);
+}
+}  // namespace
+int main()
+{
+  std::string name{"ostream_metric_example"};
+  initMetrics(name);
+  foo_library(name);
+}
+#else
+int main() {}
+#endif

exporters/ostream/BUILD

@@ -43,37 +43,36 @@ cc_library(
     ],
 )
 
-# TODO - Uncomment once MetricData interface is finalised
-#cc_library(
-#    name = "ostream_metric_exporter",
-#    srcs = [
-#        "src/metric_exporter.cc",
-#    ],
-#    hdrs = [
-#        "include/opentelemetry/exporters/ostream/metric_exporter.h",
-#    ],
-#    strip_include_prefix = "include",
-#    tags = [
-#        "metrics",
-#        "ostream",
-#    ],
-#    deps = [
-#        "//sdk/src/metrics",
-#    ],
-#)
+cc_library(
+    name = "ostream_metric_exporter",
+    srcs = [
+        "src/metric_exporter.cc",
+    ],
+    hdrs = [
+        "include/opentelemetry/exporters/ostream/metric_exporter.h",
+    ],
+    strip_include_prefix = "include",
+    tags = [
+        "metrics",
+        "ostream",
+    ],
+    deps = [
+        "//sdk/src/metrics",
+    ],
+)
 
-#cc_test(
-#    name = "ostream_metric_test",
-#    srcs = ["test/ostream_metric_test.cc"],
-#    tags = [
-#        "ostream",
-#        "test",
-#    ],
-#    deps = [
-#        ":ostream_metric_exporter",
-#        "@com_google_googletest//:gtest_main",
-#    ],
-#)
+cc_test(
+    name = "ostream_metric_test",
+    srcs = ["test/ostream_metric_test.cc"],
+    tags = [
+        "ostream",
+        "test",
+    ],
+    deps = [
+        ":ostream_metric_exporter",
+        "@com_google_googletest//:gtest_main",
+    ],
+)
 
 cc_test(
     name = "ostream_metrics_test_deprecated",

exporters/ostream/include/opentelemetry/exporters/ostream/metric_exporter.h

@@ -35,11 +35,9 @@ class OStreamMetricExporter final : public opentelemetry::sdk::metrics::MetricEx
 
   /**
    * Export
-   * @param records a span of unique pointers to metrics data
+   * @param data metrics data
    */
-  sdk::common::ExportResult Export(
-      const nostd::span<std::unique_ptr<opentelemetry::sdk::metrics::MetricData>> &records) noexcept
-      override;
+  sdk::common::ExportResult Export(const sdk::metrics::ResourceMetrics &data) noexcept override;
 
   /**
    * Force flush the exporter.
@@ -60,7 +58,9 @@ class OStreamMetricExporter final : public opentelemetry::sdk::metrics::MetricEx
   bool is_shutdown_ = false;
   mutable opentelemetry::common::SpinLockMutex lock_;
   bool isShutdown() const noexcept;
-  void printPointData(opentelemetry::sdk::metrics::PointType &point_data);
+  void printInstrumentationInfoMetricData(
+      const sdk::metrics::InstrumentationInfoMetrics &info_metrics);
+  void printPointData(const opentelemetry::sdk::metrics::PointType &point_data);
 };
 }  // namespace metrics
 }  // namespace exporter

exporters/ostream/src/metric_exporter.cc

@@ -1,68 +1,90 @@
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0
 
+#include <chrono>
 #ifndef ENABLE_METRICS_PREVIEW
-#  include "opentelemetry/exporters/ostream/metric_exporter.h"
 #  include <algorithm>
+#  include "opentelemetry/exporters/ostream/metric_exporter.h"
 #  include "opentelemetry/sdk/metrics/aggregation/default_aggregation.h"
 #  include "opentelemetry/sdk/metrics/aggregation/histogram_aggregation.h"
 #  include "opentelemetry/sdk_config.h"
 
+namespace
+{
+std::string timeToString(opentelemetry::common::SystemTimestamp time_stamp)
+{
+  std::time_t epoch_time = std::chrono::system_clock::to_time_t(time_stamp);
+  return std::ctime(&epoch_time);
+}
+}  // namespace
+
 OPENTELEMETRY_BEGIN_NAMESPACE
 namespace exporter
 {
 namespace metrics
 {
 
+template <typename Container>
+inline void printVec(std::ostream &os, Container &vec)
+{
+  using T = typename std::decay<decltype(*vec.begin())>::type;
+  os << '[';
+  if (vec.size() > 1)
+  {
+    std::copy(vec.begin(), vec.end(), std::ostream_iterator<T>(os, ", "));
+  }
+  os << ']';
+}
+
 OStreamMetricExporter::OStreamMetricExporter(std::ostream &sout) noexcept : sout_(sout) {}
 
 sdk::common::ExportResult OStreamMetricExporter::Export(
-    const nostd::span<std::unique_ptr<opentelemetry::sdk::metrics::MetricData>> &records) noexcept
+    const sdk::metrics::ResourceMetrics &data) noexcept
 {
   if (isShutdown())
   {
     OTEL_INTERNAL_LOG_ERROR("[OStream Metric] Exporting "
-                            << records.size() << " records(s) failed, exporter is shutdown");
+                            << data.instrumentation_info_metric_data_.size()
+                            << " records(s) failed, exporter is shutdown");
     return sdk::common::ExportResult::kFailure;
   }
 
-  for (auto &record : records)
+  for (auto &record : data.instrumentation_info_metric_data_)
   {
-    sout_ << "{"
-          << "\n  name        : " << record->instrumentation_library_->GetName()
-          << "\n  version     : " << record->instrumentation_library_->GetVersion();
-    printPointData(record->point_data_);
-    sout_ << "\n}\n";
+    printInstrumentationInfoMetricData(record);
   }
   return sdk::common::ExportResult::kSuccess;
 }
 
-template <typename T>
-inline void printVec(std::ostream &os, std::vector<T> &vec)
+void OStreamMetricExporter::printInstrumentationInfoMetricData(
+    const sdk::metrics::InstrumentationInfoMetrics &info_metric)
 {
-  os << '[';
-  if (vec.size() > 1)
-  {
-    std::copy(vec.begin(), vec.end() - 1, std::ostream_iterator<T>(os, ", "));
-  }
-  if (!vec.empty())
+  sout_ << "{";
+  sout_ << "\n  name\t\t: " << info_metric.instrumentation_library_->GetName()
+        << "\n  schema url\t: " << info_metric.instrumentation_library_->GetSchemaURL()
+        << "\n  version\t: " << info_metric.instrumentation_library_->GetVersion();
+  for (const auto &record : info_metric.metric_data_)
   {
-    os << vec.back();
+    sout_ << "\n  start time\t: " << timeToString(record.start_ts)
+          << "  end time\t: " << timeToString(record.end_ts)
+          << "  description\t: " << record.instrument_descriptor.description_
+          << "\n  unit\t\t: " << record.instrument_descriptor.unit_;
+
+    for (const auto &pd : record.point_data_attr_)
+    {
+      printPointData(pd.point_data);
+    }
   }
-  os << ']';
+  sout_ << "\n}\n";
 }
 
-void OStreamMetricExporter::printPointData(opentelemetry::sdk::metrics::PointType &point_data)
+void OStreamMetricExporter::printPointData(const opentelemetry::sdk::metrics::PointType &point_data)
 {
   if (nostd::holds_alternative<sdk::metrics::SumPointData>(point_data))
   {
     auto sum_point_data = nostd::get<sdk::metrics::SumPointData>(point_data);
-    sout_ << "\n  type     : SumPointData";
-    sout_ << "\n  start timestamp     : "
-          << std::to_string(sum_point_data.start_epoch_nanos_.time_since_epoch().count());
-    sout_ << "\n  end timestamp     : "
-          << std::to_string(sum_point_data.end_epoch_nanos_.time_since_epoch().count());
-    sout_ << "\n  value     : ";
+    sout_ << "\n  type\t\t: SumPointData";
+    sout_ << "\n  value\t\t: ";
     if (nostd::holds_alternative<double>(sum_point_data.value_))
     {
       sout_ << nostd::get<double>(sum_point_data.value_);
@@ -76,8 +98,6 @@ void OStreamMetricExporter::printPointData(opentelemetry::sdk::metrics::PointTyp
   {
     auto histogram_point_data = nostd::get<sdk::metrics::HistogramPointData>(point_data);
     sout_ << "\n  type     : HistogramPointData";
-    sout_ << "\n  timestamp     : "
-          << std::to_string(histogram_point_data.epoch_nanos_.time_since_epoch().count());
     sout_ << "\n  count     : " << histogram_point_data.count_;
     sout_ << "\n  sum     : ";
     if (nostd::holds_alternative<double>(histogram_point_data.sum_))
@@ -90,14 +110,14 @@ void OStreamMetricExporter::printPointData(opentelemetry::sdk::metrics::PointTyp
     }
 
     sout_ << "\n  buckets     : ";
-    if (nostd::holds_alternative<std::vector<double>>(histogram_point_data.boundaries_))
+    if (nostd::holds_alternative<std::list<double>>(histogram_point_data.boundaries_))
     {
-      auto &double_boundaries = nostd::get<std::vector<double>>(histogram_point_data.boundaries_);
+      auto &double_boundaries = nostd::get<std::list<double>>(histogram_point_data.boundaries_);
       printVec(sout_, double_boundaries);
     }
-    else if (nostd::holds_alternative<std::vector<long>>(histogram_point_data.boundaries_))
+    else if (nostd::holds_alternative<std::list<long>>(histogram_point_data.boundaries_))
     {
-      auto &long_boundaries = nostd::get<std::vector<long>>(histogram_point_data.boundaries_);
+      auto &long_boundaries = nostd::get<std::list<long>>(histogram_point_data.boundaries_);
       printVec(sout_, long_boundaries);
     }
 
@@ -109,8 +129,8 @@ void OStreamMetricExporter::printPointData(opentelemetry::sdk::metrics::PointTyp
     auto last_point_data = nostd::get<sdk::metrics::LastValuePointData>(point_data);
     sout_ << "\n  type     : LastValuePointData";
     sout_ << "\n  timestamp     : "
-          << std::to_string(last_point_data.epoch_nanos_.time_since_epoch().count())
-          << std::boolalpha << "\n  valid     : " << last_point_data.is_lastvalue_valid_;
+          << std::to_string(last_point_data.sample_ts_.time_since_epoch().count()) << std::boolalpha
+          << "\n  valid     : " << last_point_data.is_lastvalue_valid_;
     sout_ << "\n  value     : ";
     if (nostd::holds_alternative<double>(last_point_data.value_))
     {