Add SetBrowserRequestStreamingEnabled extension method

[campersau]

Add SetBrowserRequestStreamingEnabled extension method

Browser request streaming was implemented in dotnet/runtime#91295. This adds the corresponding extension method for it.

Description

Browser request streaming requires HTTP/2 or higher server support and is currently only supported in Chromium (Chrome / Edge / ...) e.g. it does not work in Firefox or Safari.
See also https://developer.chrome.com/articles/fetch-streaming-requests/

CC @pavelsavara

[ghost]

Thanks for your PR, @campersau. Someone from the team will get assigned to your PR shortly and we'll get it reviewed.

[mkArtakMSFT]

@MackinnonBuck can you please review this? Thanks!

[javiercn]

What does it happen on unsupported browsers. Does it fallback transparently?

I'm a bit worried of adding this as it can create a performance cliff when not running on chrome/edge, which might be a nasty surprise when you run the app in Safari if you only tested on Chrome/Edge

[campersau]

What does it happen on unsupported browsers. Does it fallback transparently?

Yes, it does fallback transparently. This is the same behavior as for response streaming.
With the difference being that response streaming is available in all browser now (which means we might enable it by default dotnet/runtime#77904 (comment)).

I would be fine with closing / delaying this PR until it is avaiable in more browsers.

[pavelsavara]

I'm a bit worried of adding this as it can create a performance cliff

If this stays opt-in, then it's "use if if you know what you are doing", no ?

Maybe we could xml-doc describing the fallback behavior and perf/memory/blocking consequences.
Something like
Note: On browsers which don't support request streaming, the full request body would need to be produced first, before the actual request is made. This is same behavior as without this flag. It will also consume memory in size of full request. Please make sure that your applications is also working on browsers other than Chromium.

[matthewreiter]

I'm a bit worried of adding this as it can create a performance cliff

If this stays opt-in, then it's "use if if you know what you are doing", no ?

Maybe we could xml-doc describing the fallback behavior and perf/memory/blocking consequences. Something like Note: On browsers which don't support request streaming, the full request body would need to be produced first, before the actual request is made. This is same behavior as without this flag. It will also consume memory in size of full request. Please make sure that your applications is also working on browsers other than Chromium.

Related to this, it would be good to publicly expose whether streaming is supported (i.e. the result of calling BrowserHttpInterop.SupportsStreamingRequest) so that user code can add value in such a situation, such as showing an upload progress indicator based on how many bytes were read from the stream, which would only work properly when using streaming requests.

[javiercn]

Since this is .NET 9.0 I have no objection on this going in right now, since we have time to adjust

[ghost]

Looks like this PR hasn't been active for some time and the codebase could have been changed in the meantime.
To make sure no conflicting changes have occurred, please rerun validation before merging. You can do this by leaving an /azp run comment here (requires commit rights), or by simply closing and reopening.

[danmoseley]

@MackinnonBuck is this ready to merge or waiting on something else

[MackinnonBuck]

@danmoseley Nope, this can be merged. I'm going to re-run CI first, though.

[MackinnonBuck]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 3 pipeline(s).

[ghost]

Looks like this PR hasn't been active for some time and the codebase could have been changed in the meantime.
To make sure no conflicting changes have occurred, please rerun validation before merging. You can do this by leaving an /azp run comment here (requires commit rights), or by simply closing and reopening.

[MackinnonBuck]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 3 pipeline(s).