CHANGELOG.md

Change log

All notable changes to the LaunchDarkly's EventSource implementation for C# will be documented in this file. This project adheres to Semantic Versioning.

5.2.0 (2025-02-24)

Features

• Report event source headers on open. (#104) (e2cba63)

[5.1.0] - 2023-10-04

Changed:

• Update minimum LaunchDarkly.Logging version to 2.0.0 to share the same min version as SDK implementations.

[5.0.1] - 2022-08-24

Changed:

• Relaxed dependency constraint to allow use of LaunchDarkly.Logging 1.x or 2.x.

[5.0.0] - 2022-08-18

Changed:

• Removed EOL target framework .NET Framework 4.5.2. Lowest compatible platform versions are now .NET Core 3.1, .NET Framework 4.6.2, .NET 6.0, and .NET Standard 2.0.
• EventSource now considers any server response with an encoding other than UTF-8 to be invalid. The Server-Sent Events specification states that event streams must always use UTF-8.

Removed:

• ConfigurationBuilder.DefaultEncoding (no longer relevant since the encoding must be UTF-8).

[4.2.0] - 2022-04-19

Added:

• ConfigurationBuilder. HttpRequestModifier, for making custom modifications to outgoing HTTP requests. (Thanks, acquleo!)

[4.1.3] - 2021-10-04

Changed:

• Updated LaunchDarkly.Logging dependency to 1.0.1, to match the version used in the latest server-side .NET SDK release. Since .NET Framework is stricter about dependency versions than .NET Core, it is desirable to keep transitive dependency versions in sync in all packages used by the SDK.

[4.1.2] - 2021-05-17

Fixed:

• Fixed a memory leak in which a CancellationTokenSource instance was not disposed of after reading from the stream. This bug was introduced in the 4.0.0 release. (#77)

[4.1.1] - 2021-05-04

(The 4.1.0 release was an accidental duplicate of 4.0.0 and did not include these changes.)

Added:

• ConfigurationBuilder.ResponseStartTimeout-- added as a more accurately named replacement for ConnectionTimeout.

Deprecated:

• ConfigurationBuilder.ConnectionTimeout

[4.1.0] - 2021-05-04

This release was an accidental duplicate of 4.0.0. Please use 4.1.1 instead.

[4.0.0] - 2021-02-22

Starting with this version, the API documentation for the latest release is viewable at https://launchdarkly.github.io/dotnet-eventsource.

The 4.x major version of LaunchDarkly.EventSource will be used in the upcoming major version releases of LaunchDarkly's .NET-based SDKs. This release streamlines the API, updates platform compatibility, and improves performance.

Added:

• EventSource.Restart: this method allows the caller to trigger a connection restart even if there was not an error on the stream.
• MessageEvent.Name: previously, the event name was only available as a property of MessageReceivedEventArgs.
• ConfigurationBuilder.DefaultEncoding: sets the character encoding to use for parsing the stream data if the server did not specify an encoding in its Content-Type.
• ConfigurationBuilder.PreferDataAsUtf8Bytes: an optional mode in which EventSource will read the data: property of events as a raw UTF-8 byte array (assuming the stream encoding is UTF-8) to avoid unnecessarily allocating a UTF-16 string. This is meant as an optimization for applications that will be processing the data with a UTF-8-based API such as System.Text.Json.
• Simple EventSource(Uri) constructor for cases where you do not need any other configuration options.
• Standard .NET XML documentation of all public types and methods is now produced in the build.
• The release now publishes a Source Link package.

Changed:

• The minimum .NET Standard compatibility version is now 2.0.
• The minimum .NET Framework compatibility version is now 4.5.2.
• Logging now works through the new LaunchDarkly.Logging facade which is used by LaunchDarkly .NET-based SDKs, instead of Common.Logging.
• ConfigurationBuilder methods no longer throw any exceptions, except for one case: passing null for the stream URI. In all cases where a property has a maximum and/or minimum value, if you try to set a value outside that range it will simply be changed to the closest valid value. If two properties do not make sense to use together (such as a non-null HttpClient and a non-null HttpMessageHandler), one will simply override the other as described in the API documentation.
• ConfigurationBuilder.DelayRetryDuration is named to InitialRetryDelay, which more accurately describes its meaning.
• ConfigurationBuilder.MessageHandler is renamed to HttpMessageHandler, since that's the name of its type (also, "message" has other meanings in this API).
• The type of Configuration.HttpContentFactory is now simply Func<HttpContent> rather than using a custom delegate type.
• If you pass a Dictionary of headers to ConfigurationBuilder.RequestHeaders, it will now be copied. Previously the configuration retained a reference to the original Dictionary, which could cause problems if it was later modified.
• EventSource now implements the stream read timeout in a way that uses the task scheduler more efficiently. Previously, it executed an additional task for each read with Task.Delay; now, it uses a timed cancellation token.
• Exception messages have been rewritten for clarity and style.

Fixed:

• ConfigurationBuilder.BackoffResetThreshold had no effect; the default value was being used regardless of what you set it to.
• When reading the SSE stream, EventSource was using a case-insensitive comparison to recognize field names like event and data. The SSE specification states that field name "must be compared literally, with no case folding performed," so a field name like EVENT is invalid.

Removed:

• Removed all types and methods that were marked as deprecated/obsolete in the last 3.x version.
• Configuration no longer has a public constructor. Instances must now be created with Configuration.Builder.
• The helper class ExponentialBackoffWithDecorrelation is no longer public.

[3.4.0] - 2020-12-03

Added:

• You can now tell EventSource to use an HttpClient instance that you provide by calling ConfigurationBuilder.HttpClient. (Thanks, thorstenfleischmann!)

[3.3.3] - 2020-11-05

Added:

• The package now has a specific target for .NET Standard 2.0, in addition to the previous targets of .NET Standard 1.4 and .NET Framework 4.5. There is no functional difference between the 2.0 and 1.4 builds, but it may be desirable for .NET Core/.NET Standard code to be able to avoid linking to any .NET Standard 1.x assemblies.

[3.3.2] - 2019-10-23

Fixed:

• If a stream connection is restarted, EventSource should send a Last-Event-Id header if it previously received an event with an id field. (Thanks, fracek!)

[3.3.1] - 2019-08-08

Fixed:

• If you don't explicitly provide an HttpMessageHandler in the configuration, EventSource will now use the default HttpClient constructor; previously, it would create an instance of the standard .NET HttpMessageHandler implementation and tell the HttpClient to use that. In .NET Framework and .NET Standard, this makes no difference, but in Xamarin, calling the default HttpClient constructor may allow it to use a better HTTP implementation based on native APIs.
• Expanded and improved documentation comments.

[3.3.0] - 2019-03-26

Added:

• The EventSource now implements IDisposable. Calling Dispose() has the same effect as calling Close().

Fixed:

• Under some circumstances, a CancellationTokenSource might not be disposed of after making an HTTP request, which could cause a timer object to be leaked.

[3.2.3] - 2019-01-14

Fixed:

• The assemblies in this package now have Authenticode signatures. The release note for 3.2.1 was an error; that release did not include signatures.

[3.2.2] - 2019-01-09

Removed

• The console applications for manual testing have been removed (because the unit tests now include full end-to-end tests against a stub HTTP server).

[3.2.1] - 2019-01-09

Changed

• The published assemblies are now digitally signed as well as strong-named. Also, they are now built in Release mode and do not contain debug information.

[3.2.0] - 2018-10-24

Added

• Previously, the delay before reconnect attempts would increase exponentially only if the previous connection could not be made at all or returned an HTTP error; if it received an HTTP 200 status, the delay would be reset to the minimum even if the connection then immediately failed. Now, the new configuration property BackoffResetThreshold (default: 1 minute) specifies the length of time that a connection must stay active in order for the reconnect delay to be reset. (#37)

Fixed

• Fixed an unobserved exception that could occur following a stream timeout, which could cause a crash in .NET 4.0.

• A NullReferenceException could sometimes be logged if a stream connection failed. (#24)

[3.1.5] - 2018-08-29

Duplicate of 3.1.4, created due to a problem in the release process.

[3.1.4] - 2018-08-29

Fixed

• Fixed a bug that prevented the event source from reconnecting to the stream if it received an HTTP error status from the server (as opposed to simply losing the connection).

[3.1.3] - 2018-08-13

Fixed

• The reconnection attempt counter is no longer shared among all EventSource instances. Previously, if you connected to more than one stream, all but the first would behave as if they were reconnecting and would have a backoff delay.

[3.1.2] - 2018-08-02

Changed

• The SDK was referencing some system assemblies via <PackageReference>, which could cause dependency conflicts. These have been changed to framework <Reference>s. A redundant reference to System.Runtime was removed.

Fixed

• If the stream connection fails, there should be an increasing backoff interval before each reconnect attempt. Previously, it would log a message about waiting some number of milliseconds, but then not actually wait.

[3.1.1] - 2018-06-28

Removed

• Removed an unused dependency on Newtonsoft.Json.

[3.1.0] - 2018-06-01

Added

• The new class ConfigurationBuilder provides a validated fluent builder pattern for Configuration instances.
• The HTTP method and request body can now be specified in ConfigurationBuilder or in the Configuration constructor. The default is still to use GET and not send a request body.

[3.0.0] - 2018-02-23

Changed

• Logging is now done via Common.Logging.

Added

• EventSource now uses the interface IEventSource.

[2.2.1] - 2018-02-05

• Downgrade Microsoft.Extensions.Logging to 1.0.2 to reduce dependencies brought in when building against .NET Framework.

[2.2.0] - 2018-01-19

Added

• Exposed EventSourceServiceCancelledException as a public class.

Changed

• Removed unused and transitive dependencies.
• Added a reference to the Apache 2.0 license in LaunchDarkly.EventSource.csproj
• Improved logging. Thanks @JeffAshton!

[2.1.1] - 2017-11-29

Changed

• Move from .NET Standard 1.6 to 1.4.

[2.1.0] - 2017-11-16

Added

• Exposed the ExponentialBackoffWithDecorrelation as a public class. This class may be used to calculate exponential backoff with jitter.

Changed

• Reconnects to EventSource are now handled inline, rather than using Polly for managing retry policies.

[2.0.0] - 2017-10-11

Changed

• Removed the closeOnEndOfStream property.

[1.1.0] 2017-10-02

Added

• ConnectToEventSourceAsync now takes in a new boolean parameter, closeOnEndOfStream, which, if true, will close the EventSource connection when the end of the stream is reached.

Changed

• Fixed a bug causing causing read timeouts to never propogate.

[1.0.1] 2017-09-27

Added

• Signed EventSource Assembly.

Changed

• Change dependency on Polly to Polly-Signed.

[1.0.0] 2017-09-22

Hello world!