/// <summary>
/// Creates a new client to connect to LaunchDarkly with a custom configuration.
/// </summary>
/// <remarks>
/// <para>
/// Applications should instantiate a single instance for the lifetime of the application. In
/// unusual cases where an application needs to evaluate feature flags from different LaunchDarkly
/// projects or environments, you may create multiple clients, but they should still be retained
/// for the lifetime of the application rather than created per request or per thread.
/// </para>
/// <para>
/// Normally, the client will begin attempting to connect to LaunchDarkly as soon as you call the
/// constructor. The constructor returns as soon as any of the following things has happened:
/// </para>
/// <list type="number">
/// <item><description> It has successfully connected to LaunchDarkly and received feature flag data. In this
/// case, <see cref="Initialized"/> will be true, and the <see cref="DataSourceStatusProvider"/>
/// will return a state of <see cref="DataSourceState.Valid"/>. </description></item>
/// <item><description> It has not succeeded in connecting within the <see cref="ConfigurationBuilder.StartWaitTime(TimeSpan)"/>
/// timeout (the default for this is 5 seconds). This could happen due to a network problem or a
/// temporary service outage. In this case, <see cref="Initialized"/> will be false, and the
/// <see cref="DataSourceStatusProvider"/> will return a state of <see cref="DataSourceState.Initializing"/>,
/// indicating that the SDK will still continue trying to connect in the background. </description></item>
/// <item><description> It has encountered an unrecoverable error: for instance, LaunchDarkly has rejected the
/// SDK key. Since an invalid key will not become valid, the SDK will not retry in this case.
/// <see cref="Initialized"/> will be false, and the <see cref="DataSourceStatusProvider"/> will
/// return a state of <see cref="DataSourceState.Off"/>. </description></item>
/// </list>
/// <para>
/// If you have specified <see cref="ConfigurationBuilder.Offline"/> mode or
/// <see cref="Components.ExternalUpdatesOnly"/>, the constructor returns immediately without
/// trying to connect to LaunchDarkly.
/// </para>
/// <para>
/// Failure to connect to LaunchDarkly will never cause the constructor to throw an exception.
/// Under any circumstance where it is not able to get feature flag data from LaunchDarkly (and
/// therefore <see cref="Initialized"/> is false), if it does not have any other source of data
/// (such as a persistent data store) then feature flag evaluations will behave the same as if
/// the flags were not found: that is, they will return whatever default value is specified in
/// your code.
/// </para>
/// </remarks>
/// <param name="config">a client configuration object (which includes an SDK key)</param>
/// <example>
/// <code>
/// var config = Configuration.Builder("my-sdk-key")
/// .AllAttributesPrivate(true)
/// .EventCapacity(1000)
/// .Build();
/// var client = new LDClient(config);
/// </code>
/// </example>
/// <seealso cref="LdClient.LdClient(string)"/>
public LdClient(Configuration config)
{
_configuration = config;
var logConfig = (config.LoggingConfigurationFactory ?? Components.Logging())
.CreateLoggingConfiguration();
_log = logConfig.LogAdapter.Logger(logConfig.BaseLoggerName ?? LogNames.DefaultBase);
_log.Info("Starting LaunchDarkly client {0}",
AssemblyVersions.GetAssemblyVersionStringForType(typeof(LdClient)));
_evalLog = _log.SubLogger(LogNames.EvaluationSubLog);
var basicConfig = new BasicConfiguration(config, _log);
var httpConfig = (config.HttpConfigurationFactory ?? Components.HttpConfiguration())
.CreateHttpConfiguration(basicConfig);
ServerDiagnosticStore diagnosticStore = _configuration.DiagnosticOptOut ? null :
new ServerDiagnosticStore(_configuration, basicConfig, httpConfig);
var taskExecutor = new TaskExecutor(this, _log);
var clientContext = new LdClientContext(basicConfig, httpConfig, diagnosticStore, taskExecutor);
var dataStoreUpdates = new DataStoreUpdatesImpl(taskExecutor, _log.SubLogger(LogNames.DataStoreSubLog));
_dataStore = (_configuration.DataStoreFactory ?? Components.InMemoryDataStore)
.CreateDataStore(clientContext, dataStoreUpdates);
_dataStoreStatusProvider = new DataStoreStatusProviderImpl(_dataStore, dataStoreUpdates);
var bigSegmentsConfig = (_configuration.BigSegmentsConfigurationFactory ?? Components.BigSegments(null))
.CreateBigSegmentsConfiguration(clientContext);
_bigSegmentStoreWrapper = bigSegmentsConfig.Store is null ? null :
new BigSegmentStoreWrapper(
bigSegmentsConfig,
taskExecutor,
_log.SubLogger(LogNames.BigSegmentsSubLog)
);
_bigSegmentStoreStatusProvider = new BigSegmentStoreStatusProviderImpl(_bigSegmentStoreWrapper);
_evaluator = new Evaluator(
GetFlag,
GetSegment,
_bigSegmentStoreWrapper == null ? (Func <string, BigSegmentsInternalTypes.BigSegmentsQueryResult>)null :
_bigSegmentStoreWrapper.GetUserMembership,
_log
);
var eventProcessorFactory =
config.Offline ? Components.NoEvents :
(_configuration.EventProcessorFactory ?? Components.SendEvents());
_eventProcessor = eventProcessorFactory.CreateEventProcessor(clientContext);
var dataSourceUpdates = new DataSourceUpdatesImpl(_dataStore, _dataStoreStatusProvider,
taskExecutor, _log, logConfig.LogDataSourceOutageAsErrorAfter);
IDataSourceFactory dataSourceFactory =
config.Offline ? Components.ExternalUpdatesOnly :
(_configuration.DataSourceFactory ?? Components.StreamingDataSource());
_dataSource = dataSourceFactory.CreateDataSource(clientContext, dataSourceUpdates);
_dataSourceStatusProvider = new DataSourceStatusProviderImpl(dataSourceUpdates);
_flagTracker = new FlagTrackerImpl(dataSourceUpdates,
(string key, User user) => JsonVariation(key, user, LdValue.Null));
var initTask = _dataSource.Start();
if (!(_dataSource is ComponentsImpl.NullDataSource))
{
_log.Info("Waiting up to {0} milliseconds for LaunchDarkly client to start...",
_configuration.StartWaitTime.TotalMilliseconds);
}
try
{
var success = initTask.Wait(_configuration.StartWaitTime);
if (!success)
{
_log.Warn("Timeout encountered waiting for LaunchDarkly client initialization");
}
}
catch (AggregateException)
{
// StreamProcessor may throw an exception if initialization fails, because we want that behavior
// in the Xamarin client. However, for backward compatibility we do not want to throw exceptions
// from the LdClient constructor in the .NET client, so we'll just swallow this.
}
}
LdClient(Configuration configuration, User user, TimeSpan startWaitTime)
{
if (user == null)
{
throw new ArgumentNullException(nameof(user));
}
_config = configuration ?? throw new ArgumentNullException(nameof(configuration));
var diagnosticStore = _config.DiagnosticOptOut ? null :
new ClientDiagnosticStore(_config, startWaitTime);
var diagnosticDisabler = _config.DiagnosticOptOut ? null :
new DiagnosticDisablerImpl();
_context = new LdClientContext(configuration, this, diagnosticStore, diagnosticDisabler);
_log = _context.BaseLogger;
_taskExecutor = _context.TaskExecutor;
diagnosticStore?.SetContext(_context);
_log.Info("Starting LaunchDarkly Client {0}", Version);
var persistenceConfiguration = (configuration.PersistenceConfigurationBuilder ?? Components.Persistence())
.CreatePersistenceConfiguration(_context);
_dataStore = new FlagDataManager(
configuration.MobileKey,
persistenceConfiguration,
_log.SubLogger(LogNames.DataStoreSubLog)
);
_userDecorator = new UserDecorator(configuration.DeviceInfo ?? new DefaultDeviceInfo(),
_dataStore.PersistentStore);
_user = _userDecorator.DecorateUser(user);
// If we had cached data for the new user, set the current in-memory flag data state to use
// that data, so that any Variation calls made before Identify has completed will use the
// last known values.
var cachedData = _dataStore.GetCachedData(_user);
if (cachedData != null)
{
_log.Debug("Cached flag data is available for this user");
_dataStore.Init(_user, cachedData.Value, false); // false means "don't rewrite the flags to persistent storage"
}
var dataSourceUpdateSink = new DataSourceUpdateSinkImpl(
_dataStore,
configuration.Offline,
_taskExecutor,
_log.SubLogger(LogNames.DataSourceSubLog)
);
_dataSourceUpdateSink = dataSourceUpdateSink;
_dataSourceStatusProvider = new DataSourceStatusProviderImpl(dataSourceUpdateSink);
_flagTracker = new FlagTrackerImpl(dataSourceUpdateSink);
var dataSourceFactory = configuration.DataSourceFactory ?? Components.StreamingDataSource();
_connectivityStateManager = Factory.CreateConnectivityStateManager(configuration);
var isConnected = _connectivityStateManager.IsConnected;
diagnosticDisabler?.SetDisabled(!isConnected || configuration.Offline);
_eventProcessor = (configuration.EventProcessorFactory ?? Components.SendEvents())
.CreateEventProcessor(_context);
_eventProcessor.SetOffline(configuration.Offline || !isConnected);
_connectionManager = new ConnectionManager(
_context,
dataSourceFactory,
_dataSourceUpdateSink,
_eventProcessor,
diagnosticDisabler,
configuration.EnableBackgroundUpdating,
_user,
_log
);
_connectionManager.SetForceOffline(configuration.Offline);
_connectionManager.SetNetworkEnabled(isConnected);
if (configuration.Offline)
{
_log.Info("Starting LaunchDarkly client in offline mode");
}
_connectivityStateManager.ConnectionChanged += networkAvailable =>
{
_log.Debug("Setting online to {0} due to a connectivity change event", networkAvailable);
_ = _connectionManager.SetNetworkEnabled(networkAvailable); // do not await the result
};
// Send an initial identify event, but only if we weren't explicitly set to be offline
if (!configuration.Offline)
{
_eventProcessor.RecordIdentifyEvent(new EventProcessorTypes.IdentifyEvent
{
Timestamp = UnixMillisecondTime.Now,
User = user
});
}
_backgroundModeManager = _config.BackgroundModeManager ?? new DefaultBackgroundModeManager();
_backgroundModeManager.BackgroundModeChanged += OnBackgroundModeChanged;
}
