This puts a lot of state into a new `LockedStream` that was formerly
guarded more coarsely by the recording lock or more granularly by
`RecordingToInsert` locks. And it restructures `LockedDatabase::flush`
to avoid holding this lock while performing SQLite operations.
Streamers write only into a recent frames buffer in RAM, which the
directory pool workers asynchronously write to disk approximately once
per GOP, where formerly there was a write call per frame.
Before, streamers could fall behind due to slow sample file directory
disk I/O calls or if writing got stuck in a retry loop, for example if
out of disk space. If Moonfire falls too far behind in receiving,
cameras tend to disconnect or (sadly) mis-frame messages because they do
not handle this case well. This removes a confusing potential cause of
such errors.
In the new model, streamers never wait for disk I/O. Frames are buffered
up to a limit. Recordings are aborted if the I/O pool falls too far
behind. There's no retry loop.
This roughly halves CPU usage as thread hand-offs and syscalls are less
common. It also enables several desirable future changes:
* audio recording (which radically increases the number of frames and
thus would otherwise significantly increase CPU usage).
* "monitor mode" (allowing live view without recording to disk),
* further CPU reductions for live view (by skipping all SQLite ops and
disk I/O).
In the new model, streamers also rarely wait for SQLite database
operations either—now only on video parameter changes. That might go
away in an upcoming change too.
The "syncer" (which synced files/dirs and kept track of what has to be
flushed into the SQLite database when) has mostly gone away too. The
directory pool workers handle the syncing now, and then they notify
a new "flusher" for the latter portion.
I'd like to go further still and have the database as a whole be owned
by a dedicated thread, the only one that uses the SQLite connection.
This prevents the tokio threads from blocking on SQLite operations.
I tried out doing so before making the streamers less dependent on the
db, but the extra thread handoffs were awful for performance.
Currently all errors from retina are `Unknown`, and these massive
backtraces are obnoxious when a camera fails on every attempt, with
only a second between.
HTTP requests were only returning the error message to the caller, not
logging locally. In most cases the problem could be understood
client-side, but there are some exceptions. E.g. if Moonfire returns
a 403 on WebSocket update, even in the Chrome debug tools's network
tab the HTTP response body seems to be unavailable. And in general,
it's nice to have more context server-side.
Logging a `response::Body` isn't practical (it could be a stream), so
convert all the web stuff to use `base::Error` err returns.
Convert the `METHOD_NOT_ALLOWED` paths to return `Ok` for now. This is a
bit lame but punts on having some way of plumbing an explicit/overridden
status code in `base::Error`, as no gRPC error kind cleanly maps to
that.
Also convert `db::auth`, rather than making up an error kind in the web
layer.
This is also a small step toward getting rid of `failure::Error`.
This gives much better information to the UI layer, getting rid of a
whole troubleshooting guide entry. See #119#132#218#219
I also restructured the code in anticipation of a new WebSocket event
stream (#40).
I think this has a minor behavior change: permission denied replies
change to HTTP 403 where they were HTTP 401. The new behavior seems
more correct, as these errors can occur when authentication has
succeeded but the session in question is not authorized for the given
operation. The UI currently doesn't care about this distinction.
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.
Inspired by the poor error message here:
https://github.com/scottlamb/moonfire-nvr/issues/107#issuecomment-777587727
* print the friendlier Display version of the error rather than Debug.
Eg, "EROFS: Read-only filesystem" rather than "Sys(EROFS)". Do this
everywhere: on command exit, on syncer retries, and on stream
retries.
* print the most immediate problem and additional lines for each
cause.
* print the backtrace or an advertisement for RUST_BACKTRACE=1 if it's
unavailable.
* also mention RUST_BACKTRACE=1 in the troubleshooting guide.
* add context in various places, including pathnames. There are surely
many places more it'd be helpful, but this is a start.
* allow subcommands to return failure without an Error.
In particular, "moonfire-nvr check" does its own error printing
because it wants to print all the errors it finds. Printing "see
earlier errors" with a meaningless stack trace seems like it'd just
confuse. But I also want to get rid of the misleading "Success" at
the end and 0 return to the OS.
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
Jared Wolff