* reset local start time at each recording boundary
* include the final frame's time when converting from wall to media time
Together at 30 fps these caused about 15 seconds of drift over 4 hours.
As noted in the changelog, this problem caused restarts to take a long
time, and the SQLite database to (slowly) grow without bound.
The problem was simple: the directory worker incorrectly aborted
`collect_garbage` if nothing was watching the result. For some
operations (e.g. reading from sample files) this is the correct
behavior, but in this case it contradicts the `Pool::collect_garbage`
contract.
`v0.7.26` introduced a busy loop error when the dir pool was shutting
down with multiple streams. This commit tests and fixes this scenario.
Also fixes a second problem in dropping a writer without an explicit
close would panic in debug mode about using (dropping) the blake3 hasher
while holding a lock. The check is meant to detect slow operations while
holding a lock. The panic wouldn't happen in release mode and probably
isn't a significant source of slowness, but fix it anyway.
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.
Now, all IO happens on each directory's two-thread pool with threads
named `dir-<PATH>`. Formerly, IO could happen on the per-stream writer
threads, per-directory reader threads, and occasional on even the tokio
worker threads.
The recording path uses more CPU than before due to extra thread
hand-offs. That will change in the next commit, which will radically
change the approach to writing.
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.
* add `/var/tmp` to the image so it doesn't have to be mounted
* remove obsolete `version: 3` from compose snippet
* mention `/usr/share/zoneinfo` in error msg and troubleshooting guide
This centralizes a major source of `.unwrap()` throughout the code,
and one that would otherwise grow with upcoming changes. The new
error message should be more clear.
`slices::Slices::get_range` was too closely following the example of
`http_serve::Entity::get_range`:
The latter is once-per-request, so just boxing is low-cost and makes
sense to easily avoid monomorphization bloat when there are potentially
many types of entity streams in one program. In Moonfire, it's used with
different streams defined in the `moonfire_nvr::web::mp4`,
`moonfire_nvr::bundled_ui`, and `http_serve::file` modules. Putting them
all into a single boxless enum would be a pain. In particular, the last
one is not a nameable type today and would need more generic parameters
to implement the caller-demanded `Entity` definition.
The former is once-per-slice, there are tons of slices per request, and
it's easy to define a two-case enum right where it's needed. So the
trade-off is quite different.
Also fix up some out-of-date comments.
There's no transcoding, so if the browser/player doesn't support these
formats, they don't play. But it will record and allow downloads, and
it seems to be working with Chrome on macOS at least.
Fixes#33
Before, it'd look like the following, as mentioned in
https://github.com/scottlamb/moonfire-nvr/issues/331:
```
2024-12-09T20:53:24.853572 WARN s-CP3PRO-main streamer{stream="CP3PRO-main"}: moonfire_nvr::streamer: sleeping for 1 s after error err=UNKNOWN
caused by: deadline has elapsed
```
...which isn't as clear as it could be, particularly if you don't notice
the `caused by` bit. After, it should look more like the following:
```
2024-12-09T20:53:24.853572 WARN s-CP3PRO-main streamer{stream="CP3PRO-main"}: moonfire_nvr::streamer: sleeping for 1 s after error err=DEADLINE_EXCEEDED unable to play stream and get first frame within PT30S
caused by: deadline has elapsed
```
* in backend, save the full reason, not just the most direct error,
which is often the useless `UNKNOWN`
* in UI, instead of wrapping in `<Typography>` which just resorts in
a weird ransom-note mixed size look, reserve space for or actually
use an icon.
`cursive` now requires `Send + Sync` bounds, so I had to switch from
`Rc<RefCell<...>>` to `Arc<Mutex<...>>`. I also coalesced some
lock calls together, hopefully without introducing any deadlocks.
I don't see any calls into the UI that would need the model while these
are held, and it seemed fine in a quick test.
Scott Lamb
Jared Wolff