feat: finalize logger

README.md

@@ -8,12 +8,13 @@ This repository is the Dart implementation of the [OpenTelemetry project](https:
 | - | - |
 | Traces | Beta |
 | Metrics | Alpha |
-| Logs | Unimplemented |
+| Logs | Beta |
 
 ## Getting Started
 
 This section will show you how to initialize the OpenTelemetry SDK, capture a span, and propagate context.
 
+### Tacers
 ### Initialize the OpenTelemetry SDK
 
 ```dart
@@ -62,6 +63,45 @@ void main(List<String> args) {
 }
 ```
 
+### Logs
+#### Initialize the OpenTelemetry SDK
+
+```dart
+import 'package:opentelemetry/sdk.dart'
+    show
+    BatchLogRecordProcessor,
+        OTLPLogExporter,
+        ConsoleExporter,
+        SimpleLogRecordProcessor,
+        TracerProviderBase;
+import 'package:opentelemetry/api.dart'
+    show registerGlobalLogProvider, globalLogProvider;
+
+void main(List<String> args) {
+  final logProvider = TracerProviderBase(processors: [
+    BatchLogRecordProcessor(
+        OTLPLogExporter(Uri.parse('https://my-collector.com/v1/traces'))),
+    SimpleLogRecordProcessor(ConsoleLogRecordExporter())
+  ]);
+
+  registerGlobalLogProvider(logProvider);
+  final tracer = globalLogProvider.get('logger-name');
+}
+```
+
+### Capture a Log 
+```dart
+import 'package:opentelemetry/api.dart' show StatusCode, globalLogProvider;
+
+void main(List<String> args) {
+  final logger = globalLogProvider.get('logger-name');
+
+  logger.emit(body: "Hello World!");
+}
+```
+
+
+
 ### Propagate Context
 
 ### Intra-process

lib/api.dart

@@ -5,22 +5,21 @@ export 'src/api/common/attribute.dart' show Attribute;
 export 'src/api/common/resource_attributes.dart' show ResourceAttributes;
 export 'src/api/common/semantic_attributes.dart' show SemanticAttributes;
 export 'src/api/context/context.dart'
-    show
-        Context,
-        ContextKey,
-        contextWithSpan,
-        contextWithSpanContext,
-        spanContextFromContext,
-        spanFromContext,
-        zone;
-export 'src/api/context/context_manager.dart'
-    show globalContextManager, registerGlobalContextManager;
+    show Context, ContextKey, contextWithSpan, contextWithSpanContext, spanContextFromContext, spanFromContext, zone;
+export 'src/api/context/context_manager.dart' show globalContextManager, registerGlobalContextManager;
 export 'src/api/exporters/span_exporter.dart' show SpanExporter;
 export 'src/api/instrumentation_library.dart' show InstrumentationLibrary;
+export 'src/api/logs/log_record.dart' show Severity;
+export 'src/api/logs/logger.dart' show Logger;
+export 'src/api/logs/logger_provider.dart' show LoggerProvider;
+export 'src/api/logs/noop/noop_logger.dart' show NoopLogger;
+export 'src/api/logs/noop/noop_logger_provider.dart' show NoopLoggerProvider;
 export 'src/api/open_telemetry.dart'
     show
+        globalLogProvider,
         globalTextMapPropagator,
         globalTracerProvider,
+        registerGlobalLogProvider,
         registerGlobalTextMapPropagator,
         registerGlobalTracerProvider,
         trace,
@@ -30,8 +29,7 @@ export 'src/api/open_telemetry.dart'
 export 'src/api/propagation/extractors/text_map_getter.dart' show TextMapGetter;
 export 'src/api/propagation/injectors/text_map_setter.dart' show TextMapSetter;
 export 'src/api/propagation/text_map_propagator.dart' show TextMapPropagator;
-export 'src/api/propagation/w3c_trace_context_propagator.dart'
-    show W3CTraceContextPropagator;
+export 'src/api/propagation/w3c_trace_context_propagator.dart' show W3CTraceContextPropagator;
 export 'src/api/span_processors/span_processor.dart' show SpanProcessor;
 export 'src/api/trace/id_generator.dart' show IdGenerator;
 export 'src/api/trace/span.dart' show Span, SpanKind;

lib/sdk.dart

@@ -1,30 +1,38 @@
 // Copyright 2021-2022 Workiva.
 // Licensed under the Apache License, Version 2.0. Please see https://github.com/Workiva/opentelemetry-dart/blob/master/LICENSE for more information
 
-export 'src/sdk/instrumentation_library.dart' show InstrumentationLibrary;
 export 'src/sdk/common/attributes.dart' show Attributes;
 export 'src/sdk/common/instrumentation_scope.dart' show InstrumentationScope;
+export 'src/sdk/instrumentation_library.dart' show InstrumentationLibrary;
+export 'src/sdk/logs/export_result.dart' show ExportResult, ExportResultCode;
+export 'src/sdk/logs/exporters/console_log_record_exporter.dart' show ConsoleLogRecordExporter;
+export 'src/sdk/logs/exporters/inmemory_log_record_exporter.dart' show InMemoryLogRecordExporter;
+export 'src/sdk/logs/exporters/log_record_exporter.dart' show LogRecordExporter;
+export 'src/sdk/logs/exporters/otlp_log_exporter.dart' show OTLPLogExporter;
+export 'src/sdk/logs/log_record.dart' show ReadableLogRecord, ReadWriteLogRecord, LogRecord;
+export 'src/sdk/logs/log_record_limit.dart' show LogRecordLimits;
+export 'src/sdk/logs/logger.dart' show Logger;
+export 'src/sdk/logs/logger_provider.dart' show LoggerProvider;
+export 'src/sdk/logs/processors/batch_log_record_processor.dart' show BatchLogRecordProcessor;
+export 'src/sdk/logs/processors/log_record_processor.dart' show LogRecordProcessor;
+export 'src/sdk/logs/processors/noop_log_processor.dart' show NoopLogRecordProcessor;
+export 'src/sdk/logs/processors/simple_log_record_processor.dart' show SimpleLogRecordProcessor;
 export 'src/sdk/resource/resource.dart' show Resource;
-export 'src/sdk/time_providers/datetime_time_provider.dart'
-    show DateTimeTimeProvider;
+export 'src/sdk/time_providers/datetime_time_provider.dart' show DateTimeTimeProvider;
 export 'src/sdk/time_providers/time_provider.dart' show TimeProvider;
-export 'src/sdk/trace/exporters/span_exporter.dart' show SpanExporter;
 export 'src/sdk/trace/exporters/collector_exporter.dart' show CollectorExporter;
 export 'src/sdk/trace/exporters/console_exporter.dart' show ConsoleExporter;
+export 'src/sdk/trace/exporters/span_exporter.dart' show SpanExporter;
 export 'src/sdk/trace/id_generator.dart' show IdGenerator;
+export 'src/sdk/trace/read_only_span.dart' show ReadOnlySpan;
+export 'src/sdk/trace/read_write_span.dart' show ReadWriteSpan;
 export 'src/sdk/trace/sampling/always_off_sampler.dart' show AlwaysOffSampler;
 export 'src/sdk/trace/sampling/always_on_sampler.dart' show AlwaysOnSampler;
-export 'src/sdk/trace/sampling/parent_based_sampler.dart'
-    show ParentBasedSampler;
+export 'src/sdk/trace/sampling/parent_based_sampler.dart' show ParentBasedSampler;
 export 'src/sdk/trace/sampling/sampler.dart' show Sampler;
-export 'src/sdk/trace/sampling/sampling_result.dart'
-    show Decision, SamplingResult;
-export 'src/sdk/trace/read_only_span.dart' show ReadOnlySpan;
-export 'src/sdk/trace/read_write_span.dart' show ReadWriteSpan;
+export 'src/sdk/trace/sampling/sampling_result.dart' show Decision, SamplingResult;
 export 'src/sdk/trace/span_limits.dart' show SpanLimits;
+export 'src/sdk/trace/span_processors/batch_processor.dart' show BatchSpanProcessor;
+export 'src/sdk/trace/span_processors/simple_processor.dart' show SimpleSpanProcessor;
 export 'src/sdk/trace/span_processors/span_processor.dart' show SpanProcessor;
-export 'src/sdk/trace/span_processors/batch_processor.dart'
-    show BatchSpanProcessor;
-export 'src/sdk/trace/span_processors/simple_processor.dart'
-    show SimpleSpanProcessor;
 export 'src/sdk/trace/tracer_provider.dart' show TracerProviderBase;

lib/src/api/context/context.dart

@@ -7,7 +7,7 @@ import 'package:collection/collection.dart';
 import 'package:logging/logging.dart';
 import 'package:meta/meta.dart';
 
-import '../../../api.dart';
+import '../../../api.dart' hide Logger;
 import '../trace/nonrecording_span.dart' show NonRecordingSpan;
 
 final Logger _log = Logger('opentelemetry');

lib/src/api/logs/logger_provider.dart

@@ -7,7 +7,7 @@ import 'package:opentelemetry/src/api/logs/logger.dart';
 abstract class LoggerProvider {
   /// Gets or creates a [Logger] instance.
   ///
-  /// The meter is identified by the combination of [name], [version],
+  /// The logger is identified by the combination of [name], [version],
   /// [schemaUrl] and [attributes]. The [name] SHOULD uniquely identify the
   /// instrumentation scope, such as the instrumentation library
   /// (e.g. io.opentelemetry.contrib.mongodb), package, module or class name.

lib/src/api/open_telemetry.dart

@@ -6,20 +6,19 @@ import 'dart:async';
 import 'package:meta/meta.dart';
 
 import '../../api.dart' as api;
-import '../experimental_api.dart';
 import 'propagation/noop_text_map_propagator.dart';
 import 'trace/noop_tracer_provider.dart';
 
 final api.TracerProvider _noopTracerProvider = NoopTracerProvider();
 final api.TextMapPropagator _noopTextMapPropagator = NoopTextMapPropagator();
-final LoggerProvider _noopLoggerProvider = NoopLoggerProvider();
-LoggerProvider _logProvider = _noopLoggerProvider;
+final api.LoggerProvider _noopLoggerProvider = api.NoopLoggerProvider();
+api.LoggerProvider _logProvider = _noopLoggerProvider;
 api.TracerProvider _tracerProvider = _noopTracerProvider;
 api.TextMapPropagator _textMapPropagator = _noopTextMapPropagator;
 
 api.TracerProvider get globalTracerProvider => _tracerProvider;
 
-LoggerProvider get globalLogProvider => _logProvider;
+api.LoggerProvider get globalLogProvider => _logProvider;
 
 api.TextMapPropagator get globalTextMapPropagator => _textMapPropagator;
 
@@ -33,7 +32,7 @@ void registerGlobalTracerProvider(api.TracerProvider tracerProvider) {
   _tracerProvider = tracerProvider;
 }
 
-void registerGlobalLogProvider(LoggerProvider logProvider) {
+void registerGlobalLogProvider(api.LoggerProvider logProvider) {
   if (_logProvider != _noopLoggerProvider) {
     throw StateError('A global LoggerProvider has already been created. '
         'registerGlobalLoggerProvider must be called only once before any '

lib/src/experimental_api.dart

@@ -11,12 +11,7 @@ export 'api/context/noop_context_manager.dart' show NoopContextManager;
 export 'api/context/zone_context.dart' show ZoneContext;
 export 'api/context/zone_context_manager.dart' show ZoneContextManager;
 export 'api/metrics/counter.dart' show Counter;
-export 'api/metrics/meter_provider.dart' show MeterProvider;
 export 'api/metrics/meter.dart' show Meter;
+export 'api/metrics/meter_provider.dart' show MeterProvider;
 export 'api/metrics/noop/noop_meter.dart' show NoopMeter;
 export 'api/trace/nonrecording_span.dart' show NonRecordingSpan;
-export 'api/logs/logger.dart' show Logger;
-export 'api/logs/log_record.dart' show Severity;
-export 'api/logs/logger_provider.dart' show LoggerProvider;
-export 'api/logs/noop/noop_logger.dart' show NoopLogger;
-export 'api/logs/noop/noop_logger_provider.dart' show NoopLoggerProvider;

lib/src/experimental_sdk.dart

@@ -7,6 +7,6 @@ library experimental_sdk;
 import 'package:meta/meta.dart';
 
 export 'sdk/metrics/counter.dart' show Counter;
-export 'sdk/metrics/meter_provider.dart' show MeterProvider;
 export 'sdk/metrics/meter.dart' show Meter;
+export 'sdk/metrics/meter_provider.dart' show MeterProvider;
 export 'sdk/resource/resource.dart' show Resource;

lib/src/sdk/common/limits.dart

@@ -4,6 +4,7 @@ import 'package:meta/meta.dart';
 
 import '../../../api.dart' as api;
 import '../../../sdk.dart' as sdk;
+import '../logs/log_record_limit.dart';
 
 /// Applies given [sdk.SpanLimits] to a list of [api.SpanLink]s.
 @protected
@@ -77,6 +78,24 @@ api.Attribute applyAttributeLimits(api.Attribute attr, sdk.SpanLimits limits) {
   return attr;
 }
 
+@protected
+api.Attribute applyAttributeLimitsForLog(api.Attribute attr, LogRecordLimits limits) {
+  // if maxNumAttributeLength is less than zero, then it has unlimited length.
+  if (limits.attributeValueLengthLimit < 0) return attr;
+
+  if (attr.value is String) {
+    attr = api.Attribute.fromString(
+        attr.key, applyAttributeLengthLimit(attr.value as String, limits.attributeValueLengthLimit));
+  } else if (attr.value is List<String>) {
+    final listString = attr.value as List<String>;
+    for (var j = 0; j < listString.length; j++) {
+      listString[j] = applyAttributeLengthLimit(listString[j], limits.attributeValueLengthLimit);
+    }
+    attr = api.Attribute.fromStringList(attr.key, listString);
+  }
+  return attr;
+}
+
 /// Truncate just strings which length is longer than configuration.
 /// Reference: https://github.com/open-telemetry/opentelemetry-java/blob/14ffacd1cdd22f5aa556eeda4a569c7f144eadf2/sdk/common/src/main/java/io/opentelemetry/sdk/internal/AttributeUtil.java#L80
 @protected

lib/src/sdk/logs/export_result.dart

@@ -0,0 +1,15 @@
+// Copyright 2021-2022 Workiva.
+// Licensed under the Apache License, Version 2.0. Please see https://github.com/Workiva/opentelemetry-dart/blob/master/LICENSE for more information
+
+class ExportResult {
+  final ExportResultCode code;
+  final Exception? error;
+  final StackTrace? stackTrace;
+
+  ExportResult({required this.code, this.error, this.stackTrace});
+}
+
+enum ExportResultCode {
+  success,
+  failed,
+}

lib/src/sdk/logs/exporters/console_log_record_exporter.dart

@@ -0,0 +1,64 @@
+// Copyright 2021-2022 Workiva.
+// Licensed under the Apache License, Version 2.0. Please see https://github.com/Workiva/opentelemetry-dart/blob/master/LICENSE for more information
+
+import 'package:opentelemetry/api.dart' as api;
+import 'package:opentelemetry/sdk.dart' as sdk;
+
+/// This is implementation of [sdk.ReadWriteLogRecordExporter] that prints LogRecords to the
+/// console. This class can be used for diagnostic purposes.
+///
+/// NOTE: This [sdk.LogRecordExporter] is intended for diagnostics use only, output rendered to the console may change at any time.
+class ConsoleLogRecordExporter implements sdk.LogRecordExporter {
+  @override
+  Future<sdk.ExportResult> export(List<sdk.ReadableLogRecord> logs) async {
+    return _sendLogRecords(logs);
+  }
+
+  /// Shutdown the exporter.
+  @override
+  Future<void> shutdown() async {}
+
+  /// Showing logs  in console
+  sdk.ExportResult _sendLogRecords(List<sdk.ReadableLogRecord> logs) {
+    for (final log in logs) {
+      print(_makeObject(log));
+    }
+    return sdk.ExportResult(code: sdk.ExportResultCode.success);
+  }
+
+  /// converts logRecord info into more readable format
+  Map<String, dynamic> _makeObject(sdk.ReadableLogRecord log) {
+    final contextInfo = {};
+    if (log.spanContext != null) {
+      contextInfo.addAll({
+        'traceId': log.spanContext!.traceId,
+        'spanId': log.spanContext!.spanId,
+        'traceFlags': log.spanContext!.traceFlags,
+      });
+    }
+    return {
+      'resource': {
+        'attributes': {
+          for (final attribute in log.resource?.attributes.keys ?? <String>[])
+            attribute: log.resource!.attributes.get(attribute),
+        },
+      },
+      'instrumentationScope': {
+        'name': log.instrumentationScope?.name,
+        'version': log.instrumentationScope?.version,
+        'schemaUrl': log.instrumentationScope?.schemaUrl,
+        'attributes': {
+          for (final attribute in log.instrumentationScope?.attributes ?? <api.Attribute>[]) attribute.key: attribute.value,
+        }
+      },
+      'timestamp': log.timeStamp,
+      'severityText': log.severityText,
+      'severityNumber': log.severityNumber,
+      'body': log.body,
+      'attributes': {
+        for (final attribute in log.attributes?.keys ?? <String>[]) attribute: log.resource!.attributes.get(attribute),
+      },
+      ...contextInfo,
+    };
+  }
+}

lib/src/sdk/logs/exporters/inmemory_log_record_exporter.dart

@@ -0,0 +1,43 @@
+// Copyright 2021-2022 Workiva.
+// Licensed under the Apache License, Version 2.0. Please see https://github.com/Workiva/opentelemetry-dart/blob/master/LICENSE for more information
+
+import 'package:meta/meta.dart';
+import 'package:opentelemetry/sdk.dart' as sdk;
+
+/// This class can be used for testing purposes. It stores the exported LogRecords
+/// in a list in memory that can be retrieved using the `getFinishedLogRecords()`
+/// method.
+class InMemoryLogRecordExporter implements sdk.LogRecordExporter {
+  var _finishedLogRecords = <sdk.ReadableLogRecord>[];
+
+  /// Indicates if the exporter has been "shutdown."
+  /// When false, exported log records will not be stored in-memory.
+  @protected
+  bool _stopped = false;
+
+  @override
+  Future<sdk.ExportResult> export(List<sdk.ReadableLogRecord> logs) async {
+    if (_stopped) {
+      return sdk.ExportResult(
+        code: sdk.ExportResultCode.failed,
+        error: Exception('Exporter has been stopped'),
+        stackTrace: StackTrace.current,
+      );
+    }
+    _finishedLogRecords.addAll(logs);
+
+    return sdk.ExportResult(code: sdk.ExportResultCode.success);
+  }
+
+  @override
+  Future<void> shutdown() async {
+    _stopped = true;
+    reset();
+  }
+
+  List<sdk.ReadableLogRecord> get finishedLogRecords => List.unmodifiable(_finishedLogRecords);
+
+  void reset() {
+    _finishedLogRecords = <sdk.ReadableLogRecord>[];
+  }
+}

lib/src/sdk/logs/exporters/log_record_exporter.dart

@@ -0,0 +1,10 @@
+// Copyright 2021-2022 Workiva.
+// Licensed under the Apache License, Version 2.0. Please see https://github.com/Workiva/opentelemetry-dart/blob/master/LICENSE for more information
+
+import 'package:opentelemetry/sdk.dart' as sdk;
+
+abstract class LogRecordExporter {
+  Future<sdk.ExportResult> export(List<sdk.ReadableLogRecord> logs);
+
+  Future<void> shutdown();
+}