Interface IEventSource

This interface defines the public members of EventSource.

Namespace: LaunchDarkly.EventSource

Assembly: LaunchDarkly.EventSource.dll

Syntax

public interface IEventSource

Properties

ReadyState

Gets the state of the EventSource connection.

Declaration

ReadyState ReadyState { get; }

Property Value

Type	Description
ReadyState

Methods

ClearTemporaryRetryDelayBounds()

Discards any bounds installed by SetTemporaryRetryDelayBounds(TimeSpan, TimeSpan), restoring the configured MaxRetryDelay(TimeSpan) and, unless a server-directed retry: value is in effect, the configured InitialRetryDelay(TimeSpan).

Declaration

void ClearTemporaryRetryDelayBounds()

Remarks

Restoring the configured bounds resets the backoff level. If no temporary bounds are in effect this does nothing. The count of reconnection attempts is not reset. Calling this is not required as the configured bounds are also restored automatically after a connection stays open for BackoffResetThreshold(TimeSpan).

A server-directed reconnection time received via the SSE retry: field is not discarded and continues to supersede InitialRetryDelay(TimeSpan), so the configured minimum may not be the one actually in use afterwards. Only a later retry: value replaces it. MaxRetryDelay(TimeSpan) is unaffected and is always restored.

See Also

SetTemporaryRetryDelayBounds(TimeSpan, TimeSpan)

Close()

Closes the connection to the SSE server. The EventSource cannot be reopened after this.

Declaration

void Close()

Restart(bool)

Triggers the same "close and retry" behavior as if an error had been encountered on the stream.

Declaration

void Restart(bool resetBackoffDelay)

Parameters

Type	Name	Description
bool	resetBackoffDelay	true if the delay before reconnection should be reset to the lowest level of the currently active bounds, which could be the temporary bounds if SetTemporaryRetryDelayBounds(TimeSpan, TimeSpan) is in effect; false if it should increase according to the usual exponential backoff logic

Remarks

If the stream is currently active, this closes the connection, waits for some amount of time as determined by the usual backoff behavior (and resetBackoffDelay), and then attempts to reconnect. If the stream is not yet connected, is already waiting to reconnect, or has been permanently shut down, this has no effect.

The method returns immediately without waiting for the reconnection to happen. You will receive Closed and Opened events when it does happen (or an Error event if the new connection attempt fails).

SetTemporaryRetryDelayBounds(TimeSpan, TimeSpan)

Temporarily replaces the bounds used to compute reconnection delays.

Declaration

void SetTemporaryRetryDelayBounds(TimeSpan initialDelay, TimeSpan maxDelay)

Parameters

Type	Name	Description
TimeSpan	initialDelay	the lowest delay to use while these bounds are in effect, unless a server-directed retry: value supersedes it
TimeSpan	maxDelay	the highest delay to use while these bounds are in effect

Remarks

The configured InitialRetryDelay(TimeSpan) and MaxRetryDelay(TimeSpan) normally govern the exponential backoff between reconnection attempts. This method installs different bounds at runtime, so a caller can slow reconnection down without reconfiguring or recreating the EventSource.

The bounds are temporary: they remain in effect until either a connection stays open for at least BackoffResetThreshold(TimeSpan), at which point the configured bounds are restored automatically, or ClearTemporaryRetryDelayBounds() is called.

Changing the bounds resets the backoff level, so the next delay is computed from the new initialDelay rather than continuing to grow from where it left off. Calling this with bounds that are already in effect does nothing, so it is safe to call repeatedly.

Negative values are changed to zero. If initialDelay is greater than maxDelay, delays are limited to maxDelay. No argument causes this method to throw, and no argument can cause a later reconnect to fail.

A server-directed reconnection time received via the SSE retry: field supersedes initialDelay, and the configured InitialRetryDelay(TimeSpan) along with it. Such a value does not affect maxDelay, so the ceiling set here continues to bound reconnection.

It is safe to call this from any thread, including from an Error handler.

See Also

ClearTemporaryRetryDelayBounds()

StartAsync()

Initiates a connection to the SSE server and begins parsing events.

Declaration

Task StartAsync()

Returns

Type	Description
Task	a Task that will be completed only when the EventSource is closed

Exceptions

Type	Condition
InvalidOperationException	if the method was called again after the stream connection was already active

Events

Closed

Occurs when the connection to the EventSource API has been closed.

Declaration

event EventHandler<StateChangedEventArgs> Closed

Event Type

Type	Description
EventHandler<StateChangedEventArgs>

CommentReceived

Occurs when a comment has been received from the EventSource API.

Declaration

event EventHandler<CommentReceivedEventArgs> CommentReceived

Event Type

Type	Description
EventHandler<CommentReceivedEventArgs>

Error

Occurs when an error has happened when the EventSource is open and processing Server Sent Events.

Declaration

event EventHandler<ExceptionEventArgs> Error

Event Type

Type	Description
EventHandler<ExceptionEventArgs>

MessageReceived

Occurs when a Server Sent Event from the EventSource API has been received.

Declaration

event EventHandler<MessageReceivedEventArgs> MessageReceived

Event Type

Type	Description
EventHandler<MessageReceivedEventArgs>

Opened

Occurs when the connection to the EventSource API has been opened.

Declaration

event EventHandler<StateChangedEventArgs> Opened

Event Type

Type	Description
EventHandler<StateChangedEventArgs>