Line data    Source code

       1              : // Copyright The OpenTelemetry Authors
       2              : // SPDX-License-Identifier: Apache-2.0
       3              : 
       4              : import 'package:dartastic_opentelemetry_api/dartastic_opentelemetry_api.dart';
       5              : 
       6              : /// Implementation of the APIObservableResult interface for asynchronous instruments.
       7              : ///
       8              : /// ObservableResult is used by asynchronous instruments to collect measurements
       9              : /// during observation callbacks. When a callback is invoked, it receives an
      10              : /// ObservableResult that it can use to record observations.
      11              : ///
      12              : /// More information:
      13              : /// https://opentelemetry.io/docs/specs/otel/metrics/api/#asynchronous-instruments
      14              : class ObservableResult<T extends num> implements APIObservableResult<T> {
      15              :   /// The list of measurements recorded during this observation.
      16              :   final List<Measurement<T>> _measurements = [];
      17              : 
      18              :   /// Records an observation with this result.
      19              :   ///
      20              :   /// This method records a measurement with the specified value and optional
      21              :   /// attributes. The measurement will be associated with the current timestamp.
      22              :   ///
      23              :   /// @param value The observed value to record
      24              :   /// @param attributes Optional attributes to associate with this observation
      25           10 :   @override
      26              :   void observe(T value, [Attributes? attributes]) {
      27              :     // Make sure we have a valid OTelFactory
      28              :     if (OTelFactory.otelFactory == null) {
      29            1 :       if (OTelLog.isWarn()) {
      30            1 :         OTelLog.warn(
      31              :           'Warning: OTelFactory.otelFactory is null in ObservableResult.observe',
      32              :         );
      33              :       }
      34              :       return;
      35              :     }
      36              : 
      37              :     // Add the measurement
      38           10 :     final measurement = OTelFactory.otelFactory!.createMeasurement<T>(
      39              :       value,
      40              :       attributes,
      41              :     );
      42           20 :     _measurements.add(measurement);
      43              :   }
      44              : 
      45              :   /// Records an observation with attributes specified as a map.
      46              :   ///
      47              :   /// This is a convenience method that converts the map to Attributes
      48              :   /// and calls observe().
      49              :   ///
      50              :   /// @param value The observed value to record
      51              :   /// @param attributes Map of attribute names to values
      52            1 :   @override
      53              :   void observeWithMap(T value, Map<String, Object> attributes) {
      54              :     if (OTelFactory.otelFactory == null) {
      55            1 :       if (OTelLog.isWarn()) {
      56            1 :         OTelLog.warn(
      57              :           'Warning: OTelFactory.otelFactory is null in '
      58              :           'ObservableResult.observeWithMap',
      59              :         );
      60              :       }
      61              :       return;
      62              :     }
      63            2 :     observe(value, attributes.toAttributes());
      64              :   }
      65              : 
      66              :   /// Returns all measurements recorded by this result.
      67              :   ///
      68              :   /// This method is used by the SDK to collect measurements after
      69              :   /// an observation callback has been executed.
      70              :   ///
      71              :   /// @return An unmodifiable list of all measurements recorded
      72           10 :   @override
      73           20 :   List<Measurement<T>> get measurements => List.unmodifiable(_measurements);
      74              : }