We now treat util like a leaf module and
use "require" to import it everywhere it's used.
An earlier version of this commit moved
util into our "shared" library, but we
decided to wait on that. Once we're ready
to do that, we should only need to do a
simple search/replace on various
require/zrequire statements plus a small
tweak to one of the custom linter checks.
It turns out we don't really need util.js
for our most immediate code-sharing goal,
which is to reuse our markdown code on
mobile. There's a little bit of cleanup
still remaining to break the dependency,
but it's minor.
The util module still calls the global
blueslip module in one place, but that
code is about to be removed in the next
few commits.
I am pretty confident that once we start
sharing things like the typeahead code
more aggressively, we'll start having
dependencies on util. The module is barely
more than 300 lines long, so we'll probably
just move the whole thing into shared
rather than break it apart. Also, we
can continue to nibble away at the
cruftier parts of the module.
Zulip has had a small use of WebSockets (specifically, for the code
path of sending messages, via the webapp only) since ~2013. We
originally added this use of WebSockets in the hope that the latency
benefits of doing so would allow us to avoid implementing a markdown
local echo; they were not. Further, HTTP/2 may have eliminated the
latency difference we hoped to exploit by using WebSockets in any
case.
While we’d originally imagined using WebSockets for other endpoints,
there was never a good justification for moving more components to the
WebSockets system.
This WebSockets code path had a lot of downsides/complexity,
including:
* The messy hack involving constructing an emulated request object to
hook into doing Django requests.
* The `message_senders` queue processor system, which increases RAM
needs and must be provisioned independently from the rest of the
server).
* A duplicate check_send_receive_time Nagios test specific to
WebSockets.
* The requirement for users to have their firewalls/NATs allow
WebSocket connections, and a setting to disable them for networks
where WebSockets don’t work.
* Dependencies on the SockJS family of libraries, which has at times
been poorly maintained, and periodically throws random JavaScript
exceptions in our production environments without a deep enough
traceback to effectively investigate.
* A total of about 1600 lines of our code related to the feature.
* Increased load on the Tornado system, especially around a Zulip
server restart, and especially for large installations like
zulipchat.com, resulting in extra delay before messages can be sent
again.
As detailed in
https://github.com/zulip/zulip/pull/12862#issuecomment-536152397, it
appears that removing WebSockets moderately increases the time it
takes for the `send_message` API query to return from the server, but
does not significantly change the time between when a message is sent
and when it is received by clients. We don’t understand the reason
for that change (suggesting the possibility of a measurement error),
and even if it is a real change, we consider that potential small
latency regression to be acceptable.
If we later want WebSockets, we’ll likely want to just use Django
Channels.
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
This commit was originally automatically generated using `tools/lint
--only=eslint --fix`. It was then modified by tabbott to contain only
changes to a set of files that are unlikely to result in significant
merge conflicts with any open pull request, excluding about 20 files.
His plan is to merge the remaining changes with more precise care,
potentially involving merging parts of conflicting pull requests
before running the `eslint --fix` operation.
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
The js_typings directory is not set up correctly for us to add new
type declarations for untyped external modules. The correct
configuration would be something like
{
"compilerOptions": {
"baseUrl": ".",
"paths": {
"*": ["js_typings/*"],
},
"typeRoots": ["js_typings"],
},
"exclude": [
"js_typings",
],
}
but that configuration is incompatible with using the same directory
for _internal_ modules like the ones declared here.
Also, correct some mistakes the generation of this list.
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
Steve Howell
Anders Kaseorg