feat: logs api

lib/src/api/logs/log_record.dart

@@ -0,0 +1,30 @@
+// 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
+
+enum Severity {
+  unspecified,
+  trace,
+  trace2,
+  trace3,
+  trace4,
+  debug,
+  debug2,
+  debug3,
+  debug4,
+  info,
+  info2,
+  info3,
+  info4,
+  warn,
+  warn2,
+  warn3,
+  warn4,
+  error,
+  error2,
+  error3,
+  error4,
+  fatal,
+  fatal2,
+  fatal3,
+  fatal4,
+}

lib/src/api/logs/logger.dart

@@ -0,0 +1,18 @@
+// 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 '../../../api.dart' as api;
+import '../../../sdk.dart' as sdk;
+import 'log_record.dart';
+
+abstract class Logger {
+  void emit({
+    sdk.Attributes? attributes,
+    api.Context? context,
+    dynamic body,
+    DateTime? observedTimestamp,
+    Severity? severityNumber,
+    String? severityText,
+    DateTime? timeStamp,
+  });
+}

lib/src/api/logs/logger_provider.dart

@@ -0,0 +1,24 @@
+// 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';
+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],
+  /// [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.
+  /// The [version] specifies the version of the instrumentation scope if the
+  /// scope has a version (e.g. a library version). The [schemaUrl] identifies
+  /// the schema this provider adheres to.  The [attributes] specifies
+  /// attributes to associate with emitted telemetry.
+  Logger get(
+    String name, {
+    String version = '',
+    String schemaUrl = '',
+    List<Attribute> attributes = const [],
+  });
+}

lib/src/api/logs/noop/noop_logger.dart

@@ -0,0 +1,22 @@
+// 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/src/api/context/context.dart';
+import 'package:opentelemetry/src/api/logs/log_record.dart';
+import 'package:opentelemetry/src/api/logs/logger.dart';
+import 'package:opentelemetry/src/sdk/common/attributes.dart';
+
+class NoopLogger implements Logger {
+  const NoopLogger();
+
+  @override
+  void emit({
+    Attributes? attributes,
+    Context? context,
+    dynamic body,
+    DateTime? observedTimestamp,
+    Severity? severityNumber,
+    String? severityText,
+    DateTime? timeStamp,
+  }) {}
+}

lib/src/api/logs/noop/noop_logger_provider.dart

@@ -0,0 +1,18 @@
+// 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/src/api/common/attribute.dart';
+import 'package:opentelemetry/src/api/logs/logger.dart';
+import 'package:opentelemetry/src/api/logs/logger_provider.dart';
+import 'package:opentelemetry/src/api/logs/noop/noop_logger.dart';
+
+class NoopLoggerProvider implements LoggerProvider {
+  @override
+  Logger get(
+    String name, {
+    String version = '',
+    String schemaUrl = '',
+    List<Attribute> attributes = const [],
+  }) =>
+      const NoopLogger();
+}

lib/src/api/open_telemetry.dart

@@ -6,16 +6,21 @@ 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;
 api.TracerProvider _tracerProvider = _noopTracerProvider;
 api.TextMapPropagator _textMapPropagator = _noopTextMapPropagator;
 
 api.TracerProvider get globalTracerProvider => _tracerProvider;
 
+LoggerProvider get globalLogProvider => _logProvider;
+
 api.TextMapPropagator get globalTextMapPropagator => _textMapPropagator;
 
 void registerGlobalTracerProvider(api.TracerProvider tracerProvider) {
@@ -28,6 +33,16 @@ void registerGlobalTracerProvider(api.TracerProvider tracerProvider) {
   _tracerProvider = tracerProvider;
 }
 
+void registerGlobalLogProvider(LoggerProvider logProvider) {
+  if (_logProvider != _noopLoggerProvider) {
+    throw StateError('A global LoggerProvider has already been created. '
+        'registerGlobalLoggerProvider must be called only once before any '
+        'calls to the getter globalLoggerProvider.');
+  }
+
+  _logProvider = logProvider;
+}
+
 void registerGlobalTextMapPropagator(api.TextMapPropagator textMapPropagator) {
   if (_textMapPropagator != _noopTextMapPropagator) {
     throw StateError('A global TextMapPropagator has already been created. '

lib/src/experimental_api.dart

@@ -15,3 +15,8 @@ export 'api/metrics/meter_provider.dart' show MeterProvider;
 export 'api/metrics/meter.dart' show Meter;
 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;

test/unit/api/logs/noop/noop_logger_provider_test.dart

@@ -0,0 +1,13 @@
+// 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
+
+@TestOn('vm')
+import 'package:opentelemetry/src/experimental_api.dart' as api;
+import 'package:test/test.dart';
+
+void main() {
+  test('returns noop logger', () {
+    final noopLoggerProvider = api.NoopLoggerProvider();
+    expect(noopLoggerProvider.get('test'), const api.NoopLogger());
+  });
+}