Line data    Source code

       1              : // Copyright The OpenTelemetry Authors
       2              : // SPDX-License-Identifier: Apache-2.0
       3              : 
       4              : library;
       5              : 
       6              : import 'package:dartastic_opentelemetry_api/dartastic_opentelemetry_api.dart';
       7              : import 'package:meta/meta.dart';
       8              : 
       9              : import '../otel.dart';
      10              : 
      11              : part 'resource_create.dart';
      12              : 
      13              : /// Represents a resource, which captures identifying information about the entities
      14              : /// for which signals (stats, traces, and logs) are reported.
      15              : ///
      16              : /// A Resource is an immutable collection of attributes that provide information
      17              : /// about the entity producing telemetry. Resources are a core concept of OpenTelemetry's
      18              : /// identity model.
      19              : ///
      20              : /// More information:
      21              : /// https://opentelemetry.io/docs/specs/otel/resource/sdk/
      22              : ///
      23              : /// Note: Per [OTEP 0265](https://github.com/open-telemetry/opentelemetry-specification/blob/main/oteps/0265-event-vision.md),
      24              : /// span events are being deprecated and will be replaced by the Logging API.
      25              : @immutable
      26              : class Resource {
      27              :   final Attributes _attributes;
      28              :   final String? _schemaUrl;
      29              : 
      30              :   /// An empty resource with no attributes.
      31              :   ///
      32              :   /// This is a convenience constant for when no resource attributes are needed.
      33          270 :   static final Resource empty = Resource._(OTel.attributesFromMap({}));
      34              : 
      35              :   /// Gets the attributes describing this resource.
      36          256 :   Attributes get attributes => _attributes;
      37              : 
      38              :   /// Gets the schema URL for this resource's attributes, if any.
      39            4 :   String? get schemaUrl => _schemaUrl;
      40              : 
      41              :   /// Private constructor for creating Resource instances.
      42              :   ///
      43              :   /// Resources should be created through the [OTel.resource] method
      44              :   /// or [ResourceCreate.create] method, not directly.
      45          128 :   Resource._(Attributes attributes, [String? schemaUrl])
      46              :       : _attributes = attributes,
      47              :         _schemaUrl = schemaUrl;
      48              : 
      49              :   /// Merges this resource with another resource.
      50              :   ///
      51              :   /// The resulting resource contains the combined attributes of both resources.
      52              :   /// If there are attributes with the same key, the attributes from the other
      53              :   /// resource will take precedence.
      54              :   ///
      55              :   /// For schema URLs, the following rules apply:
      56              :   /// - If one schema URL is empty, use the non-empty one
      57              :   /// - If both schema URLs are the same, use that schema URL
      58              :   /// - If both schema URLs are different and non-empty, use the other resource's schema URL
      59              :   ///
      60              :   /// @param other The resource to merge with this resource
      61              :   /// @return A new resource with the merged attributes
      62           54 :   Resource merge(Resource other) {
      63           54 :     final mergedMap = <String, Object>{};
      64              : 
      65              :     // Add current attributes
      66          215 :     _attributes.toMap().forEach((key, value) {
      67          106 :       mergedMap[key] = value.value;
      68              :     });
      69              : 
      70              :     // Add other resource's attributes (they take precedence)
      71          216 :     other._attributes.toMap().forEach((key, value) {
      72          108 :       mergedMap[key] = value.value;
      73              :     });
      74              : 
      75              :     // Handle schema URL merging according to spec
      76              :     String? mergedSchemaUrl;
      77           56 :     if (_schemaUrl == null || _schemaUrl!.isEmpty) {
      78           54 :       mergedSchemaUrl = other._schemaUrl;
      79            3 :     } else if (other._schemaUrl == null || other._schemaUrl!.isEmpty) {
      80            1 :       mergedSchemaUrl = _schemaUrl;
      81            3 :     } else if (_schemaUrl == other._schemaUrl) {
      82            1 :       mergedSchemaUrl = _schemaUrl;
      83              :     } else {
      84              :       // Schema URLs are different and non-empty - this is a merging error
      85              :       // The spec says the result is implementation-specific
      86              :       // We'll choose to use the updating resource's schema URL
      87            1 :       mergedSchemaUrl = other._schemaUrl;
      88              :     }
      89              : 
      90           54 :     final result = Resource._(
      91           54 :       OTel.attributesFromMap(mergedMap),
      92              :       mergedSchemaUrl,
      93              :     );
      94              : 
      95           54 :     if (OTelLog.isDebug()) {
      96           54 :       OTelLog.debug('Resource merge result attributes:');
      97          216 :       result._attributes.toList().forEach((attr) {
      98          216 :         if (attr.key == 'tenant_id' || attr.key == 'service.name') {
      99          208 :           OTelLog.debug('  ${attr.key}: ${attr.value}');
     100              :         }
     101              :       });
     102              :     }
     103              : 
     104              :     return result;
     105              :   }
     106              : }