Add Meter and MeterProvider in the SDK

api/include/opentelemetry/metrics/meter.h

@@ -39,12 +39,12 @@ class Meter
   virtual nostd::shared_ptr<Counter<long>> CreateLongCounter(
       nostd::string_view name,
       nostd::string_view description = "",
-      nostd::string_view unit        = "1") noexcept = 0;
+      nostd::string_view unit        = "") noexcept = 0;
 
   virtual nostd::shared_ptr<Counter<double>> CreateDoubleCounter(
       nostd::string_view name,
       nostd::string_view description = "",
-      nostd::string_view unit        = "1") noexcept = 0;
+      nostd::string_view unit        = "") noexcept = 0;
 
   /**
    * Creates a Asynchronouse (Observable) counter with the passed characteristics and returns a
@@ -60,13 +60,13 @@ class Meter
       nostd::string_view name,
       void (*callback)(ObserverResult<long> &),
       nostd::string_view description = "",
-      nostd::string_view unit        = "1") noexcept = 0;
+      nostd::string_view unit        = "") noexcept = 0;
 
   virtual nostd::shared_ptr<ObservableCounter<double>> CreateDoubleObservableCounter(
       nostd::string_view name,
       void (*callback)(ObserverResult<double> &),
       nostd::string_view description = "",
-      nostd::string_view unit        = "1") noexcept = 0;
+      nostd::string_view unit        = "") noexcept = 0;
 
   /**
    * Creates a Histogram with the passed characteristics and returns a shared_ptr to that Histogram.
@@ -79,12 +79,12 @@ class Meter
   virtual nostd::shared_ptr<Histogram<long>> CreateLongHistogram(
       nostd::string_view name,
       nostd::string_view description = "",
-      nostd::string_view unit        = "1") noexcept = 0;
+      nostd::string_view unit        = "") noexcept = 0;
 
   virtual nostd::shared_ptr<Histogram<double>> CreateDoubleHistogram(
       nostd::string_view name,
       nostd::string_view description = "",
-      nostd::string_view unit        = "1") noexcept = 0;
+      nostd::string_view unit        = "") noexcept = 0;
 
   /**
    * Creates a Asynchronouse (Observable) Gauge with the passed characteristics and returns a
@@ -100,13 +100,13 @@ class Meter
       nostd::string_view name,
       void (*callback)(ObserverResult<long> &),
       nostd::string_view description = "",
-      nostd::string_view unit        = "1") noexcept = 0;
+      nostd::string_view unit        = "") noexcept = 0;
 
   virtual nostd::shared_ptr<ObservableGauge<double>> CreateDoubleObservableGauge(
       nostd::string_view name,
       void (*callback)(ObserverResult<double> &),
       nostd::string_view description = "",
-      nostd::string_view unit        = "1") noexcept = 0;
+      nostd::string_view unit        = "") noexcept = 0;
 
   /**
    * Creates an UpDownCounter with the passed characteristics and returns a shared_ptr to that
@@ -120,12 +120,12 @@ class Meter
   virtual nostd::shared_ptr<UpDownCounter<long>> CreateLongUpDownCounter(
       nostd::string_view name,
       nostd::string_view description = "",
-      nostd::string_view unit        = "1") noexcept = 0;
+      nostd::string_view unit        = "") noexcept = 0;
 
   virtual nostd::shared_ptr<UpDownCounter<double>> CreateDoubleUpDownCounter(
       nostd::string_view name,
       nostd::string_view description = "",
-      nostd::string_view unit        = "1") noexcept = 0;
+      nostd::string_view unit        = "") noexcept = 0;
 
   /**
    * Creates a Asynchronouse (Observable) UpDownCounter with the passed characteristics and returns
@@ -141,13 +141,13 @@ class Meter
       nostd::string_view name,
       void (*callback)(ObserverResult<long> &),
       nostd::string_view description = "",
-      nostd::string_view unit        = "1") noexcept = 0;
+      nostd::string_view unit        = "") noexcept = 0;
 
   virtual nostd::shared_ptr<ObservableUpDownCounter<double>> CreateDoubleObservableUpDownCounter(
       nostd::string_view name,
       void (*callback)(ObserverResult<double> &),
       nostd::string_view description = "",
-      nostd::string_view unit        = "1") noexcept = 0;
+      nostd::string_view unit        = "") noexcept = 0;
 };
 }  // namespace metrics
 OPENTELEMETRY_END_NAMESPACE

sdk/include/opentelemetry/sdk/common/global_log_handler.h

@@ -164,12 +164,12 @@ OPENTELEMETRY_END_NAMESPACE
 #endif
 
 #if OTEL_INTERNAL_LOG_LEVEL >= OTEL_INTERNAL_LOG_LEVEL_WARN
-#  define OTEL_INTERNAL_LOG_WARN_1_ARGS(message)                                                  \
-    OTEL_INTERNAL_LOG_DISPATCH(opentelemetry::sdk::common::internal_log::LogLevel::Warn, message, \
-                               {})
-#  define OTEL_INTERNAL_LOG_WARN_2_ARGS(message, attributes)                                      \
-    OTEL_INTERNAL_LOG_DISPATCH(opentelemetry::sdk::common::internal_log::LogLevel::Warn, message, \
-                               attributes)
+#  define OTEL_INTERNAL_LOG_WARN_1_ARGS(message)                                            \
+    OTEL_INTERNAL_LOG_DISPATCH(opentelemetry::sdk::common::internal_log::LogLevel::Warning, \
+                               message, {})
+#  define OTEL_INTERNAL_LOG_WARN_2_ARGS(message, attributes)                                \
+    OTEL_INTERNAL_LOG_DISPATCH(opentelemetry::sdk::common::internal_log::LogLevel::Warning, \
+                               message, attributes)
 #  define OTEL_INTERNAL_LOG_WARN_MACRO(...)                                   \
     OTEL_INTERNAL_LOG_GET_3RD_ARG(__VA_ARGS__, OTEL_INTERNAL_LOG_WARN_2_ARGS, \
                                   OTEL_INTERNAL_LOG_WARN_1_ARGS)

sdk/include/opentelemetry/sdk/metrics/meter.h

@@ -0,0 +1,109 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+#ifndef ENABLE_METRICS_PREVIEW
+#  include <chrono>
+#  include "opentelemetry/metrics/meter.h"
+#  include "opentelemetry/sdk/instrumentationlibrary/instrumentation_library.h"
+#  include "opentelemetry/sdk/metrics/meter_context.h"
+#  include "opentelemetry/sdk/resource/resource.h"
+#  include "opentelemetry/version.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace sdk
+{
+namespace metrics
+{
+class Meter final : public opentelemetry::metrics::Meter
+{
+public:
+  /** Construct a new Meter with the given  pipeline. */
+  explicit Meter(std::shared_ptr<sdk::metrics::MeterContext> context,
+                 std::unique_ptr<opentelemetry::sdk::instrumentationlibrary::InstrumentationLibrary>
+                     instrumentation_library =
+                         opentelemetry::sdk::instrumentationlibrary::InstrumentationLibrary::Create(
+                             "")) noexcept;
+
+  nostd::shared_ptr<opentelemetry::metrics::Counter<long>> CreateLongCounter(
+      nostd::string_view name,
+      nostd::string_view description = "",
+      nostd::string_view unit        = "") noexcept override;
+
+  nostd::shared_ptr<opentelemetry::metrics::Counter<double>> CreateDoubleCounter(
+      nostd::string_view name,
+      nostd::string_view description = "",
+      nostd::string_view unit        = "") noexcept override;
+
+  nostd::shared_ptr<opentelemetry::metrics::ObservableCounter<long>> CreateLongObservableCounter(
+      nostd::string_view name,
+      void (*callback)(opentelemetry::metrics::ObserverResult<long> &),
+      nostd::string_view description = "",
+      nostd::string_view unit        = "") noexcept override;
+
+  nostd::shared_ptr<opentelemetry::metrics::ObservableCounter<double>>
+  CreateDoubleObservableCounter(nostd::string_view name,
+                                void (*callback)(opentelemetry::metrics::ObserverResult<double> &),
+                                nostd::string_view description = "",
+                                nostd::string_view unit        = "1") noexcept override;
+
+  nostd::shared_ptr<opentelemetry::metrics::Histogram<long>> CreateLongHistogram(
+      nostd::string_view name,
+      nostd::string_view description = "",
+      nostd::string_view unit        = "") noexcept override;
+
+  nostd::shared_ptr<opentelemetry::metrics::Histogram<double>> CreateDoubleHistogram(
+      nostd::string_view name,
+      nostd::string_view description = "",
+      nostd::string_view unit        = "") noexcept override;
+
+  nostd::shared_ptr<opentelemetry::metrics::ObservableGauge<long>> CreateLongObservableGauge(
+      nostd::string_view name,
+      void (*callback)(opentelemetry::metrics::ObserverResult<long> &),
+      nostd::string_view description = "",
+      nostd::string_view unit        = "") noexcept override;
+
+  nostd::shared_ptr<opentelemetry::metrics::ObservableGauge<double>> CreateDoubleObservableGauge(
+      nostd::string_view name,
+      void (*callback)(opentelemetry::metrics::ObserverResult<double> &),
+      nostd::string_view description = "",
+      nostd::string_view unit        = "") noexcept override;
+
+  nostd::shared_ptr<opentelemetry::metrics::UpDownCounter<long>> CreateLongUpDownCounter(
+      nostd::string_view name,
+      nostd::string_view description = "",
+      nostd::string_view unit        = "") noexcept override;
+
+  nostd::shared_ptr<opentelemetry::metrics::UpDownCounter<double>> CreateDoubleUpDownCounter(
+      nostd::string_view name,
+      nostd::string_view description = "",
+      nostd::string_view unit        = "") noexcept override;
+
+  nostd::shared_ptr<opentelemetry::metrics::ObservableUpDownCounter<long>>
+  CreateLongObservableUpDownCounter(
+      nostd::string_view name,
+      void (*callback)(opentelemetry::metrics::ObserverResult<long> &),
+      nostd::string_view description = "",
+      nostd::string_view unit        = "") noexcept override;
+
+  nostd::shared_ptr<opentelemetry::metrics::ObservableUpDownCounter<double>>
+  CreateDoubleObservableUpDownCounter(
+      nostd::string_view name,
+      void (*callback)(opentelemetry::metrics::ObserverResult<double> &),
+      nostd::string_view description = "",
+      nostd::string_view unit        = "") noexcept override;
+
+  /** Returns the associated instruementation library */
+  const sdk::instrumentationlibrary::InstrumentationLibrary &GetInstrumentationLibrary()
+      const noexcept;
+
+private:
+  // order of declaration is important here - instrumentation library should destroy after
+  // meter-context.
+  std::shared_ptr<sdk::instrumentationlibrary::InstrumentationLibrary> instrumentation_library_;
+  std::shared_ptr<sdk::metrics::MeterContext> context_;
+};
+}  // namespace metrics
+}  // namespace sdk
+OPENTELEMETRY_END_NAMESPACE
+#endif

sdk/include/opentelemetry/sdk/metrics/meter_context.h

@@ -0,0 +1,98 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#pragma once
+#ifndef ENABLE_METRICS_PREVIEW
+#  include <chrono>
+#  include <memory>
+#  include <vector>
+#  include "opentelemetry/sdk/metrics/metric_exporter.h"
+#  include "opentelemetry/sdk/metrics/metric_reader.h"
+#  include "opentelemetry/sdk/metrics/view.h"
+#  include "opentelemetry/sdk/resource/resource.h"
+#  include "opentelemetry/version.h"
+
+OPENTELEMETRY_BEGIN_NAMESPACE
+namespace sdk
+{
+namespace metrics
+{
+/**
+ * A class which stores the MeterProvider context.
+
+ */
+class MeterContext
+{
+public:
+  /**
+   * Initialize a new meter provider
+   * @param exporters The exporters to be configured with meter context
+   * @param readers The readers to be configured with meter context.
+   * @param views The views to be configured with meter context.
+   * @param resource  The resource for this meter context.
+   */
+  MeterContext(std::vector<std::unique_ptr<sdk::metrics::MetricExporter>> &&exporters,
+               std::vector<std::unique_ptr<MetricReader>> &&readers,
+               std::vector<std::unique_ptr<View>> &&views,
+               opentelemetry::sdk::resource::Resource resource =
+                   opentelemetry::sdk::resource::Resource::Create({})) noexcept;
+
+  /**
+   * Obtain the resource associated with this meter context.
+   * @return The resource for this meter context
+   */
+  const opentelemetry::sdk::resource::Resource &GetResource() const noexcept;
+
+  /**
+   * Attaches a metric exporter to list of configured exporters for this Meter context.
+   * @param exporter The metric exporter for this meter context. This
+   * must not be a nullptr.
+   *
+   * Note: This exporter may not receive any in-flight meter data, but will get newly created meter
+   * data. Note: This method is not thread safe, and should ideally be called from main thread.
+   */
+  void AddMetricExporter(std::unique_ptr<MetricExporter> exporter) noexcept;
+
+  /**
+   * Attaches a metric reader to list of configured readers for this Meter context.
+   * @param reader The metric reader for this meter context. This
+   * must not be a nullptr.
+   *
+   * Note: This reader may not receive any in-flight meter data, but will get newly created meter
+   * data. Note: This method is not thread safe, and should ideally be called from main thread.
+   */
+  void AddMetricReader(std::unique_ptr<MetricReader> reader) noexcept;
+
+  /**
+   * Attaches a View to list of configured Views for this Meter context.
+   * @param view The Views for this meter context. This
+   * must not be a nullptr.
+   *
+   * Note: This view may not receive any in-flight meter data, but will get newly created meter
+   * data. Note: This method is not thread safe, and should ideally be called from main thread.
+   */
+  void AddView(std::unique_ptr<View> view) noexcept;
+
+  /**
+   * Force all active Exporters and Readers to flush any buffered meter data
+   * within the given timeout.
+   */
+
+  bool ForceFlush(std::chrono::microseconds timeout = (std::chrono::microseconds::max)()) noexcept;
+
+  /**
+   * Shutdown the Exporters and Readers associated with this meter provider.
+   */
+  bool Shutdown() noexcept;
+
+private:
+  opentelemetry::sdk::resource::Resource resource_;
+  std::vector<std::unique_ptr<MetricExporter>> exporters_;
+  std::vector<std::unique_ptr<MetricReader>> readers_;
+  std::vector<std::unique_ptr<View>> views_;
+};
+
+}  // namespace metrics
+}  // namespace sdk
+OPENTELEMETRY_END_NAMESPACE
+#endif