After a frustrating search for a suitable channel to use for shutdown
(tokio::sync:⌚:Receiver and
futures::future::Shared<tokio::sync::oneshot::Receiver> didn't look
quite right) in which I rethought my life decisions, I finally just made
my own (server/base/shutdown.rs). We can easily poll it or wait for it
in async or sync contexts. Most importantly, it's convenient; not that
it really matters here, but it's also efficient.
We now do a slightly better job of propagating a "graceful" shutdown
signal, and this channel will give us tools to improve it over time.
* Shut down even when writer or syncer operations are stuck. Fixes#117
* Not done yet: streamers should instantly shut down without waiting for
a connection attempt or frame or something. I'll probably
implement that when removing --rtsp-library=ffmpeg. The code should be
cleaner then.
* Not done yet: fix a couple places that sleep for up to a second when
they could shut down immediately. I just need to do the plumbing for
mock clocks to work.
I also implemented an immediate shutdown mode, activated by a second
signal. I think this will mitigate the streamer wait situation.
This isn't well-tested and doesn't yet support an initial connection
timeout. But in a quick test, it successfully returns video!
I'd like to do some more aggressive code restructuring for zero-copy
and to have only one writer thread per sample file directory (rather
than the syncer thread + one writer thread per RTSP stream). But I'll
likely wait until I drop support for ffmpeg entirely.
I'm tired of all the boilerplate, so use the new
GPL-3.0-linking-exception license identifier instead in all the server
components.
I left the ui stuff alone because I'm just going to replace it (#111).
Add a checker for the header because it's easy to forget.
I want to make the project more accessible by not expecting folks to
match my idiosyncratic style. Now almost [1] everything is written
in the "standard" style. CI enforces this.
[1] "Almost": I used #[rustfmt::skip] in a few sections where I felt
aligning things in columns significantly improves readability.
Besides being more clear about what belongs to which, this helps with
docker caching. The server and ui parts are only rebuilt when their
respective subdirectories change.
Extend this a bit further by making the webpack build not depend on
the target architecture. And adding cache dirs so parts of the server
and ui build process can be reused when layer-wide caching fails.
Scott Lamb