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              : import '../data/metric.dart';
       7              : import '../data/metric_point.dart';
       8              : import '../meter.dart';
       9              : import '../storage/sum_storage.dart';
      10              : import 'base_instrument.dart';
      11              : 
      12              : /// UpDownCounter is a synchronous instrument that records additive values.
      13              : ///
      14              : /// An UpDownCounter is used to measure a value that increases and decreases.
      15              : /// For example, the number of active requests, queue size, pool size.
      16              : class UpDownCounter<T extends num>
      17              :     implements APIUpDownCounter<T>, SDKInstrument {
      18              :   /// The underlying API UpDownCounter.
      19              :   final APIUpDownCounter<T> _apiCounter;
      20              : 
      21              :   /// The Meter that created this UpDownCounter.
      22              :   final Meter _meter;
      23              : 
      24              :   /// Storage for accumulating up-down counter measurements.
      25              :   final SumStorage<T> _storage = SumStorage<T>(isMonotonic: false);
      26              : 
      27              :   /// Creates a new UpDownCounter instance.
      28            5 :   UpDownCounter({required APIUpDownCounter<T> apiCounter, required Meter meter})
      29              :       : _apiCounter = apiCounter,
      30              :         _meter = meter {
      31              :     // Register this instrument with the meter provider
      32           25 :     _meter.provider.registerInstrument(_meter.name, this);
      33              :   }
      34              : 
      35            5 :   @override
      36           10 :   String get name => _apiCounter.name;
      37              : 
      38            2 :   @override
      39            4 :   String? get unit => _apiCounter.unit;
      40              : 
      41            2 :   @override
      42            4 :   String? get description => _apiCounter.description;
      43              : 
      44            1 :   @override
      45            2 :   bool get enabled => _meter.enabled;
      46              : 
      47            5 :   @override
      48            5 :   APIMeter get meter => _meter;
      49              : 
      50            1 :   @override
      51              :   bool get isCounter => false;
      52              : 
      53            1 :   @override
      54              :   bool get isUpDownCounter => true;
      55              : 
      56            1 :   @override
      57              :   bool get isGauge => false;
      58              : 
      59            1 :   @override
      60              :   bool get isHistogram => false;
      61              : 
      62            3 :   @override
      63              :   void add(T value, [Attributes? attributes]) {
      64              :     // First use the API implementation (no-op by default)
      65            6 :     _apiCounter.add(value, attributes);
      66              : 
      67              :     // In the SDK, we only check the meter's enabled state
      68            6 :     if (!_meter.enabled) return;
      69              : 
      70              :     // Record the measurement in our storage
      71            6 :     _storage.record(value, attributes);
      72              :   }
      73              : 
      74            1 :   @override
      75              :   void addWithMap(T value, Map<String, Object> attributeMap) {
      76              :     // Just convert to Attributes and call add
      77              :     final attributes =
      78            2 :         attributeMap.isEmpty ? null : attributeMap.toAttributes();
      79            1 :     add(value, attributes);
      80              :   }
      81              : 
      82              :   /// Gets the current value of the counter for a specific set of attributes.
      83              :   /// If no attributes are provided, returns the sum of all values across all attributes.
      84            3 :   T getValue([Attributes? attributes]) {
      85            6 :     return _storage.getValue(attributes);
      86              :   }
      87              : 
      88              :   /// Gets the current points for this counter.
      89              :   /// This is used by the SDK to collect metrics.
      90            1 :   List<MetricPoint<T>> collectPoints() {
      91            2 :     return _storage.collectPoints();
      92              :   }
      93              : 
      94            1 :   @override
      95              :   List<Metric> collectMetrics() {
      96            2 :     if (!enabled) return [];
      97              : 
      98              :     // Get the points from storage
      99            1 :     final points = collectPoints();
     100              : 
     101            1 :     if (points.isEmpty) return [];
     102              : 
     103              :     // Create a metric with the collected points
     104            1 :     final metric = Metric(
     105            1 :       name: name,
     106            1 :       description: description,
     107            1 :       unit: unit,
     108              :       type: MetricType.sum, // UpDownCounter is still a sum, just not monotonic
     109              :       points: points,
     110              :     );
     111              : 
     112            1 :     return [metric];
     113              :   }
     114              : 
     115              :   /// Resets the counter. This is only used for Delta temporality.
     116            2 :   void reset() {
     117            4 :     _storage.reset();
     118              :   }
     119              : }