Add preview feature-flag/macro for metrics

api/include/opentelemetry/metrics/async_instruments.h

@@ -1,7 +1,8 @@
-#pragma once
+#ifdef ENABLE_METRICS_PREVIEW
+#  pragma once
 
-#include "instrument.h"
-#include "observer_result.h"
+#  include "instrument.h"
+#  include "observer_result.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
 namespace metrics
@@ -81,3 +82,4 @@ class UpDownSumObserver : virtual public AsynchronousInstrument<T>
 
 }  // namespace metrics
 OPENTELEMETRY_END_NAMESPACE
+#endif

api/include/opentelemetry/metrics/instrument.h

@@ -1,10 +1,11 @@
-#pragma once
+#ifdef ENABLE_METRIC_PREVIEW
+#  pragma once
 
-#include <iostream>
-#include "opentelemetry/common/attribute_value.h"
-#include "opentelemetry/common/key_value_iterable_view.h"
-#include "opentelemetry/nostd/shared_ptr.h"
-#include "opentelemetry/nostd/string_view.h"
+#  include <iostream>
+#  include "opentelemetry/common/attribute_value.h"
+#  include "opentelemetry/common/key_value_iterable_view.h"
+#  include "opentelemetry/nostd/shared_ptr.h"
+#  include "opentelemetry/nostd/string_view.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
 namespace metrics
@@ -202,3 +203,4 @@ class AsynchronousInstrument : virtual public Instrument
 
 }  // namespace metrics
 OPENTELEMETRY_END_NAMESPACE
+#endif

api/include/opentelemetry/metrics/meter.h

@@ -1,12 +1,13 @@
-#pragma once
+#ifdef ENABLE_METRIC_PREVIEW
+#  pragma once
 
-#include "opentelemetry/metrics/async_instruments.h"
-#include "opentelemetry/metrics/instrument.h"
-#include "opentelemetry/metrics/sync_instruments.h"
-#include "opentelemetry/nostd/shared_ptr.h"
-#include "opentelemetry/nostd/span.h"
-#include "opentelemetry/nostd/string_view.h"
-#include "opentelemetry/version.h"
+#  include "opentelemetry/metrics/async_instruments.h"
+#  include "opentelemetry/metrics/instrument.h"
+#  include "opentelemetry/metrics/sync_instruments.h"
+#  include "opentelemetry/nostd/shared_ptr.h"
+#  include "opentelemetry/nostd/span.h"
+#  include "opentelemetry/nostd/string_view.h"
+#  include "opentelemetry/version.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
 namespace metrics
@@ -281,3 +282,4 @@ class Meter
 };
 }  // namespace metrics
 OPENTELEMETRY_END_NAMESPACE
+#endif

api/include/opentelemetry/metrics/meter_provider.h

@@ -1,8 +1,9 @@
-#pragma once
+#ifdef ENABLE_METRIC_PREVIEW
+#  pragma once
 
-#include "opentelemetry/metrics/meter.h"
-#include "opentelemetry/nostd/shared_ptr.h"
-#include "opentelemetry/nostd/string_view.h"
+#  include "opentelemetry/metrics/meter.h"
+#  include "opentelemetry/nostd/shared_ptr.h"
+#  include "opentelemetry/nostd/string_view.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
 namespace metrics
@@ -25,3 +26,4 @@ class MeterProvider
 };
 }  // namespace metrics
 OPENTELEMETRY_END_NAMESPACE
+#endif

api/include/opentelemetry/metrics/noop.h

@@ -1,19 +1,20 @@
-#pragma once
+#ifdef ENABLE_METRIC_PREVIEW
+#  pragma once
 // Please refer to provider.h for documentation on how to obtain a Meter object.
 //
 // This file is part of the internal implementation of OpenTelemetry. Nothing in this file should be
 // used directly. Please refer to meter.h for documentation on these interfaces.
 
-#include "opentelemetry/metrics/async_instruments.h"
-#include "opentelemetry/metrics/instrument.h"
-#include "opentelemetry/metrics/meter.h"
-#include "opentelemetry/metrics/meter_provider.h"
-#include "opentelemetry/metrics/sync_instruments.h"
-#include "opentelemetry/nostd/string_view.h"
-#include "opentelemetry/nostd/unique_ptr.h"
-#include "opentelemetry/version.h"
+#  include "opentelemetry/metrics/async_instruments.h"
+#  include "opentelemetry/metrics/instrument.h"
+#  include "opentelemetry/metrics/meter.h"
+#  include "opentelemetry/metrics/meter_provider.h"
+#  include "opentelemetry/metrics/sync_instruments.h"
+#  include "opentelemetry/nostd/string_view.h"
+#  include "opentelemetry/nostd/unique_ptr.h"
+#  include "opentelemetry/version.h"
 
-#include <memory>
+#  include <memory>
 
 // TODO: Create generic short pattern for opentelemetry::common and opentelemetry::trace and others
 // as necessary
@@ -647,3 +648,4 @@ class NoopMeterProvider final : public opentelemetry::metrics::MeterProvider
 };
 }  // namespace metrics
 OPENTELEMETRY_END_NAMESPACE
+#endif

api/include/opentelemetry/metrics/observer_result.h

@@ -1,7 +1,8 @@
-#pragma once
+#ifdef ENABLE_METRIC_PREVIEW
+#  pragma once
 
-#include "instrument.h"
-#include "opentelemetry/nostd/shared_ptr.h"
+#  include "instrument.h"
+#  include "opentelemetry/nostd/shared_ptr.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
 namespace metrics
@@ -34,3 +35,4 @@ class ObserverResult
 
 }  // namespace metrics
 OPENTELEMETRY_END_NAMESPACE
+#endif

api/include/opentelemetry/metrics/provider.h

@@ -1,11 +1,12 @@
-#pragma once
+#ifdef ENABLE_METRIC_PREVIEW
+#  pragma once
 
-#include <mutex>
+#  include <mutex>
 
-#include "opentelemetry/common/spin_lock_mutex.h"
-#include "opentelemetry/metrics/meter_provider.h"
-#include "opentelemetry/metrics/noop.h"
-#include "opentelemetry/nostd/shared_ptr.h"
+#  include "opentelemetry/common/spin_lock_mutex.h"
+#  include "opentelemetry/metrics/meter_provider.h"
+#  include "opentelemetry/metrics/noop.h"
+#  include "opentelemetry/nostd/shared_ptr.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
 namespace metrics
@@ -53,3 +54,4 @@ class Provider
 
 }  // namespace metrics
 OPENTELEMETRY_END_NAMESPACE
+#endif

api/include/opentelemetry/metrics/sync_instruments.h

@@ -1,6 +1,7 @@
-#pragma once
+#ifdef ENABLE_METRIC_PREVIEW
+#  pragma once
 
-#include "instrument.h"
+#  include "instrument.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
 namespace metrics
@@ -174,3 +175,4 @@ class ValueRecorder : virtual public SynchronousInstrument<T>
 
 }  // namespace metrics
 OPENTELEMETRY_END_NAMESPACE
+#endif

api/test/metrics/meter_provider_test.cc

@@ -1,8 +1,9 @@
-#include "opentelemetry/metrics/provider.h"
-#include "opentelemetry/nostd/shared_ptr.h"
-
 #include <gtest/gtest.h>
 
+#ifdef ENABLE_METRIC_PREVIEW
+#  include "opentelemetry/metrics/provider.h"
+#  include "opentelemetry/nostd/shared_ptr.h"
+
 using opentelemetry::metrics::Meter;
 using opentelemetry::metrics::MeterProvider;
 using opentelemetry::metrics::Provider;
@@ -39,3 +40,9 @@ TEST(Provider, MultipleMeterProviders)
 
   ASSERT_NE(Provider::GetMeterProvider(), tf);
 }
+#else
+TEST(Provider, DummyTest)
+{
+  // empty
+}
+#endif

api/test/metrics/noop_instrument_test.cc

@@ -1,8 +1,10 @@
 #include <gtest/gtest.h>
-#include <cstring>
-#include <map>
-#include <string>
-#include "opentelemetry/metrics/noop.h"
+
+#ifdef ENABLE_METRIC_PREVIEW
+#  include <cstring>
+#  include <map>
+#  include <string>
+#  include "opentelemetry/metrics/noop.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
 namespace metrics
@@ -183,3 +185,9 @@ TEST(ValueRecorder, Record)
 
 }  // namespace metrics
 OPENTELEMETRY_END_NAMESPACE
+#else
+TEST(ValueRecorder, DummyTest)
+{
+  // empty
+}
+#endif

api/test/metrics/noop_metrics_test.cc

@@ -1,11 +1,13 @@
 #include <gtest/gtest.h>
-#include "opentelemetry/metrics/instrument.h"
-#include "opentelemetry/metrics/noop.h"
-#include "opentelemetry/metrics/observer_result.h"
-#include "opentelemetry/metrics/sync_instruments.h"
 
-#include <array>
-#include <memory>
+#ifdef ENABLE_METRIC_PREVIEW
+#  include "opentelemetry/metrics/instrument.h"
+#  include "opentelemetry/metrics/noop.h"
+#  include "opentelemetry/metrics/observer_result.h"
+#  include "opentelemetry/metrics/sync_instruments.h"
+
+#  include <array>
+#  include <memory>
 
 OPENTELEMETRY_BEGIN_NAMESPACE
 
@@ -76,3 +78,9 @@ TEST(NoopMeter, RecordBatch)
   m->RecordDoubleBatch(labelkv, dsp, dval);
 }
 OPENTELEMETRY_END_NAMESPACE
+#else
+TEST(NoopMeter, DummyTest)
+{
+  // empty
+}
+#endif

examples/metrics_simple/main.cc

@@ -1,9 +1,10 @@
-#include "opentelemetry/exporters/ostream/metrics_exporter.h"
-#include "opentelemetry/metrics/provider.h"
-#include "opentelemetry/sdk/metrics/controller.h"
-#include "opentelemetry/sdk/metrics/meter.h"
-#include "opentelemetry/sdk/metrics/meter_provider.h"
-#include "opentelemetry/sdk/metrics/ungrouped_processor.h"
+#ifdef ENABLE_METRIC_PREVIEW
+#  include "opentelemetry/exporters/ostream/metrics_exporter.h"
+#  include "opentelemetry/metrics/provider.h"
+#  include "opentelemetry/sdk/metrics/controller.h"
+#  include "opentelemetry/sdk/metrics/meter.h"
+#  include "opentelemetry/sdk/metrics/meter_provider.h"
+#  include "opentelemetry/sdk/metrics/ungrouped_processor.h"
 
 namespace sdkmetrics = opentelemetry::sdk::metrics;
 namespace nostd      = opentelemetry::nostd;
@@ -105,3 +106,9 @@ int main()
   }
   ControllerStateful.stop();
 }
+#else
+int main()
+{
+  // empty
+}
+#endif

exporters/ostream/src/metrics_exporter.cc

@@ -1,4 +1,5 @@
-#include "opentelemetry/exporters/ostream/metrics_exporter.h"
+#ifdef ENABLE_METRICS_PREVIEW
+#  include "opentelemetry/exporters/ostream/metrics_exporter.h"
 
 OPENTELEMETRY_BEGIN_NAMESPACE
 namespace exporter
@@ -48,3 +49,4 @@ sdk::common::ExportResult OStreamMetricsExporter::Export(
 }  // namespace metrics
 }  // namespace exporter
 OPENTELEMETRY_END_NAMESPACE
+#endif

exporters/ostream/test/ostream_metrics_test.cc

@@ -1,14 +1,16 @@
-#include "opentelemetry/exporters/ostream/metrics_exporter.h"
-#include "opentelemetry/sdk/metrics/aggregator/counter_aggregator.h"
-#include "opentelemetry/sdk/metrics/aggregator/exact_aggregator.h"
-#include "opentelemetry/sdk/metrics/aggregator/gauge_aggregator.h"
-#include "opentelemetry/sdk/metrics/aggregator/min_max_sum_count_aggregator.h"
-#include "opentelemetry/sdk/metrics/aggregator/sketch_aggregator.h"
-#include "opentelemetry/sdk/metrics/exporter.h"
-#include "opentelemetry/sdk/metrics/record.h"
-
 #include <gtest/gtest.h>
-#include <iostream>
+#ifdef ENABLE_METRICS_PREVIEW
+
+#  include "opentelemetry/exporters/ostream/metrics_exporter.h"
+#  include "opentelemetry/sdk/metrics/aggregator/counter_aggregator.h"
+#  include "opentelemetry/sdk/metrics/aggregator/exact_aggregator.h"
+#  include "opentelemetry/sdk/metrics/aggregator/gauge_aggregator.h"
+#  include "opentelemetry/sdk/metrics/aggregator/min_max_sum_count_aggregator.h"
+#  include "opentelemetry/sdk/metrics/aggregator/sketch_aggregator.h"
+#  include "opentelemetry/sdk/metrics/exporter.h"
+#  include "opentelemetry/sdk/metrics/record.h"
+
+#  include <iostream>
 
 namespace sdkmetrics  = opentelemetry::sdk::metrics;
 namespace metrics_api = opentelemetry::metrics;
@@ -288,3 +290,9 @@ TEST(OStreamMetricsExporter, PrintSketch)
 
   ASSERT_EQ(stdoutOutput.str(), expectedOutput);
 }
+#else
+TEST(OStreamMetricsExporter, DummyTest)
+{
+  // empty
+}
+#endif

exporters/prometheus/include/opentelemetry/exporters/prometheus/prometheus_collector.h

@@ -13,17 +13,17 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+#ifdef ENABLE_METRIC_PREVIEW
+#  pragma once
 
-#pragma once
+#  include <memory>
+#  include <mutex>
+#  include <vector>
 
-#include <memory>
-#include <mutex>
-#include <vector>
-
-#include "opentelemetry/sdk/metrics/record.h"
-#include "prometheus/collectable.h"
-#include "prometheus/metric_family.h"
-#include "prometheus_exporter_utils.h"
+#  include "opentelemetry/sdk/metrics/record.h"
+#  include "prometheus/collectable.h"
+#  include "prometheus/metric_family.h"
+#  include "prometheus_exporter_utils.h"
 
 namespace prometheus_client = ::prometheus;
 namespace metric_sdk        = opentelemetry::sdk::metrics;
@@ -98,3 +98,4 @@ class PrometheusCollector : public prometheus_client::Collectable
 }  // namespace prometheus
 }  // namespace exporter
 OPENTELEMETRY_END_NAMESPACE
+#endif

exporters/prometheus/include/opentelemetry/exporters/prometheus/prometheus_exporter_utils.h

@@ -14,13 +14,14 @@
  * limitations under the License.
  */
 
-#pragma once
+#ifdef ENABLE_METRIC_PREVIEW
+#  pragma once
 
-#include <string>
-#include <vector>
+#  include <string>
+#  include <vector>
 
-#include "opentelemetry/sdk/metrics/record.h"
-#include "prometheus/metric_family.h"
+#  include "opentelemetry/sdk/metrics/record.h"
+#  include "prometheus/metric_family.h"
 
 namespace metric_sdk = opentelemetry::sdk::metrics;
 
@@ -180,3 +181,4 @@ class PrometheusExporterUtils
 }  // namespace prometheus
 }  // namespace exporter
 OPENTELEMETRY_END_NAMESPACE
+#endif