1236219 - Handle EventStream requests

Status: NEW

(DevTools :: Netmonitor, enhancement)

Description

[Rob Janssen]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:43.0) Gecko/20100101 Firefox/43.0
Build ID: 2015121300

Steps to reproduce:

Open a website that uses the "event source" mechanism (Content-type: text/event-stream) and opened Tools->Web Console, clicked the event source and then Network->Response.


Actual results:

Nothing was shown at that time.  Later, a whole bunch of events were shown at once.
Probably the events are read in a buffer of e.g. 4K before being displayed.


Expected results:

The events should be shown immediately when they arrive, or after a short timeout of
e.g. half a second.
When the event source produces little output, it should be possible to see it "immediately".

Comment 1

[Rob Janssen]

Actually it looks more like there is no fixed buffer but the "timeout" before displaying what
has come in is very long.

Comment 2

[Nicolas Chevobbe [:nchevobbe]]

Hello Rob, sorry for the very late reply !

Do you still experience this ? I can't find how to reproduce the issue with the link you provided.
Thanks !

Comment 3

[Rob Janssen]

I tested it and it still doesn't work in Firefix ESR 52.9.0
Probably I am just expecting too much.  I expected to see the eventsource "live" as it comes
in (in tail -f fashion) and it looks like the consile simply isn't offering that.

Comment 4

[Nicolas Chevobbe [:nchevobbe]]

(In reply to Rob Janssen from comment #3)
> I tested it and it still doesn't work in Firefix ESR 52.9.0
> Probably I am just expecting too much.  I expected to see the eventsource
> "live" as it comes
> in (in tail -f fashion) and it looks like the consile simply isn't offering
> that.

52 is pretty old right now , could you test on 60 *which is ESR too) ? Thanks !

Comment 5

[Rob Janssen]

I am using Debian Buster which has 52.9.0 which is dated Jun 25, 2018 which I would not
consider pretty old on Aug 3.   It is also the product firefox-esr-latest on the download server.

Anyway, I don't believe in bugs like this magically fixing themselves.

Comment 6

[Julien Wajsberg [:julienw]]

Hey Rob,

Debian now has Firefox 60 as its firefox-esr. Can you please check if the issue still happens on your side with this version? Thanks a lot!
The console was completely rewritten between 52 and 60, that's why the problem might have resolved.

Comment 7

[Rob Janssen]

I have now version 60.3.0esr and indeed the look of the console is completely different, but the
behaviour appears to be the same.  The eventsources are displayed without info until some large
timeout and then they show what was received up to that point.  There is no dynamic trace.
You can try it yourself using the URL in the Details.
When you open that page and look around, and you see some red and yellow bar in the output, at
that time eventsource data is coming in that changes the size of the bar continuously and while
you see it in action on the screen, nothing is shown in the Network Response window until you
wait two minutes and then suddenly a chunk appears.
(when there are only static grey bars there is no activity on the system being monitored there
and the eventsource is nearly silent.  try it at some other time near morning and evening MET)

Comment 8

[Julien Wajsberg [:julienw]]

NI Nicolas for coming up with further actions.

Comment 9

[Nicolas Chevobbe [:nchevobbe]]

okay, I opened it in Chrome and now it makes more sense to me.
So in chrome, there's an "EventStream" tab, that displays the messages received.

Comment 10

[Nicolas Chevobbe [:nchevobbe]]

Attachment: Chrome DevTools "EventStream" tab