feat: Add support for configuration changed event.

Remove handler on shutdown.

Async send provider events.

Fix events.

src/LaunchDarkly.OpenFeature.ServerProvider/Provider.StatusProvider.cs

@@ -46,9 +46,9 @@ private async Task SafeWrite(ProviderEventPayload payload)
  {
  await _eventChannel.Writer.WriteAsync(payload).ConfigureAwait(false);
  }
- catch
+ catch(System.Exception e)
  {
- _logger.Warn("Failed to send provider status event");
+ _logger.Warn($"Failed to send provider status event: {e.Message}");
  }
  }
 

src/LaunchDarkly.OpenFeature.ServerProvider/Provider.cs

@@ -1,5 +1,7 @@
 using System;
+using System.Collections.Generic;
 using System.Threading.Tasks;
+using LaunchDarkly.Logging;
 using LaunchDarkly.Sdk;
 using LaunchDarkly.Sdk.Internal.Concurrent;
 using LaunchDarkly.Sdk.Server;
@@ -28,19 +30,22 @@ public sealed partial class Provider : FeatureProvider
  private readonly ILdClient _client;
  private readonly EvalContextConverter _contextConverter;
  private readonly StatusProvider _statusProvider;
+
  private readonly AtomicBoolean _initializeCalled = new AtomicBoolean(false);
+
  // There is no support for void task completion, so we use bool as a dummy result type.
  private readonly TaskCompletionSource<bool> _initCompletion = new TaskCompletionSource<bool>();
+ private readonly Logger _logger;
 
  private const string ProviderShutdownMessage =
  "the provider has encountered a permanent error or been shutdown";
 
  internal Provider(ILdClient client)
  {
  _client = client;
- var logger = _client.GetLogger().SubLogger(NameSpace);
- _statusProvider = new StatusProvider(EventChannel, _metadata.Name, logger);
- _contextConverter = new EvalContextConverter(logger);
+ _logger = _client.GetLogger().SubLogger(NameSpace);
+ _statusProvider = new StatusProvider(EventChannel, _metadata.Name, _logger);
+ _contextConverter = new EvalContextConverter(_logger);
  }
 
  /// <summary>
@@ -127,6 +132,8 @@ public override Task Initialize(EvaluationContext context)
  return _initCompletion.Task;
  }
 
+ _client.FlagTracker.FlagChanged += FlagChangeHandler;
+
  _client.DataSourceStatusProvider.StatusChanged += StatusChangeHandler;
 
  // We start listening for status changes and then we check the current status change. If we do not check
@@ -152,13 +159,36 @@ public override Task Initialize(EvaluationContext context)
  public override Task Shutdown()
  {
  _client.DataSourceStatusProvider.StatusChanged -= StatusChangeHandler;
+ _client.FlagTracker.FlagChanged -= FlagChangeHandler;
  (_client as IDisposable)?.Dispose();
  _statusProvider.SetStatus(ProviderStatus.NotReady);
  return Task.CompletedTask;
  }
 
  #endregion
 
+ private void FlagChangeHandler(object sender, FlagChangeEvent changeEvent)
+ {
+ Task.Run(() => SafeWriteChangeEvent(changeEvent)).ConfigureAwait(false);
+ }
+
+ private async Task SafeWriteChangeEvent(FlagChangeEvent changeEvent)
+ {
+ try
+ {
+ await EventChannel.Writer.WriteAsync(new ProviderEventPayload
+ {
+ ProviderName = _metadata.Name,
+ Type = ProviderEventTypes.ProviderConfigurationChanged,
+ FlagsChanged = new List<string>{changeEvent.Key},
+ }).ConfigureAwait(false);
+ }
+ catch(Exception e)
+ {
+ _logger.Warn($"Encountered an error sending configuration changed events: {e.Message}");
+ }
+ }
+
  private void StatusChangeHandler(object sender, DataSourceStatus status)
  {
  switch (status.State)