Synchronous Metric collection (Delta , Cumulative)

exporters/ostream/BUILD

@@ -43,36 +43,35 @@ cc_library(
     ],
 )
 
-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",
-    ],
-)
+#TODO MetricData is still changing, uncomment once it is final
+#    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",

sdk/include/opentelemetry/sdk/metrics/aggregation/aggregation.h

@@ -11,24 +11,42 @@ namespace sdk
 {
 namespace metrics
 {
-class InstrumentMonotonicityAwareAggregation
-{
-public:
-  InstrumentMonotonicityAwareAggregation(bool is_monotonic) : is_monotonic_(is_monotonic) {}
-  bool IsMonotonic() { return is_monotonic_; }
-
-private:
-  bool is_monotonic_;
-};
-
 class Aggregation
 {
 public:
   virtual void Aggregate(long value, const PointAttributes &attributes = {}) noexcept = 0;
 
   virtual void Aggregate(double value, const PointAttributes &attributes = {}) noexcept = 0;
 
-  virtual PointType Collect() noexcept = 0;
+  /**
+   * Returns the result of the merge of the two aggregations.
+   *
+   * This should always assume that the aggregations do not overlap and merge together for a new
+   * cumulative report.
+   *
+   * @param delta the newly captured (delta) aggregation
+   * @return the result of the merge of the given aggregation.
+   */
+
+  virtual std::unique_ptr<Aggregation> Merge(Aggregation &delta) noexcept = 0;
+
+  /**
+   * Returns a new DELTA aggregation by comparing two cumulative measurements.
+   *
+   * @param next the newly captured (cumulative) aggregation.
+   * @return The resulting delta aggregation.
+   */
+  virtual std::unique_ptr<Aggregation> Diff(Aggregation &next) noexcept = 0;
+
+  /**
+   * Returns the point data that the aggregation will produce.
+   *
+   * @return PointType
+   */
+
+  virtual PointType ToPoint() noexcept = 0;
+
+  virtual ~Aggregation() = default;
 };
 
 }  // namespace metrics

sdk/include/opentelemetry/sdk/metrics/aggregation/default_aggregation.h

@@ -30,8 +30,8 @@ class DefaultAggregation
       case InstrumentType::kUpDownCounter:
       case InstrumentType::kObservableUpDownCounter:
         return (instrument_descriptor.value_type_ == InstrumentValueType::kLong)
-                   ? std::move(std::unique_ptr<Aggregation>(new LongSumAggregation(true)))
-                   : std::move(std::unique_ptr<Aggregation>(new DoubleSumAggregation(true)));
+                   ? std::move(std::unique_ptr<Aggregation>(new LongSumAggregation()))
+                   : std::move(std::unique_ptr<Aggregation>(new DoubleSumAggregation()));
         break;
       case InstrumentType::kHistogram:
         return (instrument_descriptor.value_type_ == InstrumentValueType::kLong)
@@ -79,11 +79,11 @@ class DefaultAggregation
       case AggregationType::kSum:
         if (instrument_descriptor.value_type_ == InstrumentValueType::kLong)
         {
-          return std::unique_ptr<Aggregation>(new LongSumAggregation(true));
+          return std::unique_ptr<Aggregation>(new LongSumAggregation());
         }
         else
         {
-          return std::unique_ptr<Aggregation>(new DoubleSumAggregation(true));
+          return std::unique_ptr<Aggregation>(new DoubleSumAggregation());
         }
         break;
       default:

sdk/include/opentelemetry/sdk/metrics/aggregation/drop_aggregation.h

@@ -14,6 +14,10 @@ namespace sdk
 namespace metrics
 {
 
+/**
+ * A null Aggregation which denotes no aggregation should occur.
+ */
+
 class DropAggregation : public Aggregation
 {
 public:
@@ -23,7 +27,21 @@ class DropAggregation : public Aggregation
 
   void Aggregate(double value, const PointAttributes &attributes = {}) noexcept override {}
 
-  PointType Collect() noexcept override { return DropPointData(); }
+  std::unique_ptr<Aggregation> Merge(Aggregation &delta) noexcept override
+  {
+    return std::unique_ptr<Aggregation>(new DropAggregation());
+  }
+
+  std::unique_ptr<Aggregation> Diff(Aggregation &next) noexcept override
+  {
+    return std::unique_ptr<Aggregation>(new DropAggregation());
+  }
+
+  PointType ToPoint() noexcept override
+  {
+    static DropPointData point_data;
+    return point_data;
+  }
 };
 }  // namespace metrics
 }  // namespace sdk

sdk/include/opentelemetry/sdk/metrics/aggregation/histogram_aggregation.h

@@ -13,57 +13,47 @@ namespace sdk
 {
 namespace metrics
 {
-template <class T>
-static inline void PopulateHistogramDataPoint(HistogramPointData &histogram,
-                                              opentelemetry::common::SystemTimestamp epoch_nanos,
-                                              T sum,
-                                              uint64_t count,
-                                              std::vector<uint64_t> &counts,
-                                              std::vector<T> boundaries)
-{
-  histogram.epoch_nanos_ = epoch_nanos;
-  histogram.boundaries_  = boundaries;
-  histogram.sum_         = sum;
-  histogram.counts_      = counts;
-  histogram.count_       = count;
-}
 
 class LongHistogramAggregation : public Aggregation
 {
 public:
   LongHistogramAggregation();
+  LongHistogramAggregation(HistogramPointData &&);
 
   void Aggregate(long value, const PointAttributes &attributes = {}) noexcept override;
 
   void Aggregate(double value, const PointAttributes &attributes = {}) noexcept override {}
 
-  PointType Collect() noexcept override;
+  virtual std::unique_ptr<Aggregation> Merge(Aggregation &delta) noexcept override;
+
+  virtual std::unique_ptr<Aggregation> Diff(Aggregation &next) noexcept override;
+
+  PointType ToPoint() noexcept override;
 
 private:
   opentelemetry::common::SpinLockMutex lock_;
-  std::vector<long> boundaries_;
-  long sum_;
-  std::vector<uint64_t> counts_;
-  uint64_t count_;
+  HistogramPointData point_data_;
 };
 
 class DoubleHistogramAggregation : public Aggregation
 {
 public:
   DoubleHistogramAggregation();
+  DoubleHistogramAggregation(HistogramPointData &&);
 
   void Aggregate(long value, const PointAttributes &attributes = {}) noexcept override {}
 
   void Aggregate(double value, const PointAttributes &attributes = {}) noexcept override;
 
-  PointType Collect() noexcept override;
+  virtual std::unique_ptr<Aggregation> Merge(Aggregation &delta) noexcept override;
+
+  virtual std::unique_ptr<Aggregation> Diff(Aggregation &next) noexcept override;
+
+  PointType ToPoint() noexcept override;
 
 private:
   opentelemetry::common::SpinLockMutex lock_;
-  std::vector<double> boundaries_;
-  double sum_;
-  std::vector<uint64_t> counts_;
-  uint64_t count_;
+  HistogramPointData point_data_;
 };
 
 }  // namespace metrics

sdk/include/opentelemetry/sdk/metrics/aggregation/lastvalue_aggregation.h

@@ -17,34 +17,42 @@ class LongLastValueAggregation : public Aggregation
 {
 public:
   LongLastValueAggregation();
+  LongLastValueAggregation(LastValuePointData &&);
 
   void Aggregate(long value, const PointAttributes &attributes = {}) noexcept override;
 
   void Aggregate(double value, const PointAttributes &attributes = {}) noexcept override {}
 
-  PointType Collect() noexcept override;
+  virtual std::unique_ptr<Aggregation> Merge(Aggregation &delta) noexcept override;
+
+  virtual std::unique_ptr<Aggregation> Diff(Aggregation &next) noexcept override;
+
+  PointType ToPoint() noexcept override;
 
 private:
   opentelemetry::common::SpinLockMutex lock_;
-  long value_;
-  bool is_lastvalue_valid_;
+  LastValuePointData point_data_;
 };
 
 class DoubleLastValueAggregation : public Aggregation
 {
 public:
   DoubleLastValueAggregation();
+  DoubleLastValueAggregation(LastValuePointData &&);
 
   void Aggregate(long value, const PointAttributes &attributes = {}) noexcept override {}
 
   void Aggregate(double value, const PointAttributes &attributes = {}) noexcept override;
 
-  PointType Collect() noexcept override;
+  virtual std::unique_ptr<Aggregation> Merge(Aggregation &delta) noexcept override;
+
+  virtual std::unique_ptr<Aggregation> Diff(Aggregation &next) noexcept override;
+
+  PointType ToPoint() noexcept override;
 
 private:
   opentelemetry::common::SpinLockMutex lock_;
-  double value_;
-  bool is_lastvalue_valid_;
+  LastValuePointData point_data_;
 };
 
 }  // namespace metrics

sdk/include/opentelemetry/sdk/metrics/aggregation/sum_aggregation.h

@@ -14,52 +14,46 @@ namespace sdk
 namespace metrics
 {
 
-template <class T>
-static inline void PopulateSumPointData(SumPointData &sum,
-                                        opentelemetry::common::SystemTimestamp start_ts,
-                                        opentelemetry::common::SystemTimestamp end_ts,
-                                        T value,
-                                        bool is_monotonic)
-{
-  sum.start_epoch_nanos_       = start_ts;
-  sum.end_epoch_nanos_         = end_ts;
-  sum.value_                   = value;
-  sum.is_monotonic_            = is_monotonic;
-  sum.aggregation_temporality_ = AggregationTemporality::kDelta;
-}
-
-class LongSumAggregation : public Aggregation, InstrumentMonotonicityAwareAggregation
+class LongSumAggregation : public Aggregation
 {
 public:
-  LongSumAggregation(bool is_monotonic);
+  LongSumAggregation();
+  LongSumAggregation(SumPointData &&);
 
   void Aggregate(long value, const PointAttributes &attributes = {}) noexcept override;
 
   void Aggregate(double value, const PointAttributes &attributes = {}) noexcept override {}
 
-  PointType Collect() noexcept override;
+  virtual std::unique_ptr<Aggregation> Merge(Aggregation &delta) noexcept override;
+
+  virtual std::unique_ptr<Aggregation> Diff(Aggregation &next) noexcept override;
+
+  PointType ToPoint() noexcept override;
 
 private:
   opentelemetry::common::SpinLockMutex lock_;
-  opentelemetry::common::SystemTimestamp start_epoch_nanos_;
-  long sum_;
+  SumPointData point_data_;
 };
 
-class DoubleSumAggregation : public Aggregation, InstrumentMonotonicityAwareAggregation
+class DoubleSumAggregation : public Aggregation
 {
 public:
-  DoubleSumAggregation(bool is_monotonic);
+  DoubleSumAggregation();
+  DoubleSumAggregation(SumPointData &&);
 
   void Aggregate(long value, const PointAttributes &attributes = {}) noexcept override {}
 
   void Aggregate(double value, const PointAttributes &attributes = {}) noexcept override;
 
-  PointType Collect() noexcept override;
+  virtual std::unique_ptr<Aggregation> Merge(Aggregation &delta) noexcept override;
+
+  virtual std::unique_ptr<Aggregation> Diff(Aggregation &next) noexcept override;
+
+  PointType ToPoint() noexcept override;
 
 private:
   opentelemetry::common::SpinLockMutex lock_;
-  opentelemetry::common::SystemTimestamp start_epoch_nanos_;
-  double sum_;
+  SumPointData point_data_;
 };
 
 }  // namespace metrics

sdk/include/opentelemetry/sdk/metrics/data/metric_data.h

@@ -17,18 +17,23 @@ namespace sdk
 namespace metrics
 {
 
-using PointAttributes = opentelemetry::sdk::common::AttributeMap;
+using PointAttributes = opentelemetry::sdk::common::OrderedAttributeMap;
 using PointType       = opentelemetry::nostd::
     variant<SumPointData, HistogramPointData, LastValuePointData, DropPointData>;
 
+struct PointDataAttributes
+{
+  PointAttributes attributes;
+  PointType point_data;
+};
+
 class MetricData
 {
 public:
-  opentelemetry::sdk::resource::Resource *resource_;
-  opentelemetry::sdk::instrumentationlibrary::InstrumentationLibrary *instrumentation_library_;
-  PointAttributes attributes_;
   InstrumentDescriptor instrument_descriptor;
-  PointType point_data_;
+  opentelemetry::common::SystemTimestamp start_ts;
+  opentelemetry::common::SystemTimestamp end_ts;
+  std::vector<PointDataAttributes> point_data_attr_;
 };
 
 }  // namespace metrics