Files
Scott Lamb fd7ae68657 overhaul streams!
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.
2026-02-17 11:55:55 -08:00

485 lines
17 KiB
Rust

// This file is part of Moonfire NVR, a security camera network video recorder.
// Copyright (C) 2020 The Moonfire NVR Authors; see AUTHORS and LICENSE.txt.
// SPDX-License-Identifier: GPL-v3.0-or-later WITH GPL-3.0-linking-exception.
//! Raw database access: SQLite statements which do not touch any cached state.
use crate::db::{self, CompositeId, SqlUuid};
use crate::json::GlobalConfig;
use crate::{recording, RecordingFlags};
use base::FastHashSet;
use base::{bail, err, Error, ErrorKind, ResultExt as _};
use rusqlite::{named_params, params};
use std::ops::Range;
use uuid::Uuid;
// Note: the magic number "27000000" below is recording::MAX_RECORDING_DURATION.
const LIST_RECORDINGS_BY_TIME_SQL: &str = r#"
select
recording.composite_id,
recording.run_offset,
recording.flags,
recording.start_time_90k,
recording.wall_duration_90k,
recording.media_duration_delta_90k,
recording.sample_file_bytes,
recording.video_samples,
recording.video_sync_samples,
recording.video_sample_entry_id,
recording.open_id,
recording.end_reason
from
recording
where
stream_id = :stream_id and
recording.start_time_90k > :start_time_90k - 27000000 and
recording.start_time_90k < :end_time_90k and
recording.start_time_90k + recording.wall_duration_90k > :start_time_90k and
recording.composite_id < :end_composite_id
order by
recording.start_time_90k
"#;
const LIST_RECORDINGS_BY_ID_SQL: &str = r#"
select
recording.composite_id,
recording.run_offset,
recording.flags,
recording.start_time_90k,
recording.wall_duration_90k,
recording.media_duration_delta_90k,
recording.sample_file_bytes,
recording.video_samples,
recording.video_sync_samples,
recording.video_sample_entry_id,
recording.open_id,
recording.end_reason,
recording.prev_media_duration_90k,
recording.prev_runs
from
recording
where
:start <= composite_id and
composite_id < :end
order by
recording.composite_id
"#;
const STREAM_MIN_START_SQL: &str = r#"
select
start_time_90k
from
recording
where
stream_id = :stream_id
order by start_time_90k limit 1
"#;
const STREAM_MAX_START_SQL: &str = r#"
select
start_time_90k,
wall_duration_90k
from
recording
where
stream_id = :stream_id
order by start_time_90k desc;
"#;
const LIST_OLDEST_RECORDINGS_SQL: &str = r#"
select
composite_id,
start_time_90k,
wall_duration_90k,
sample_file_bytes
from
recording
where
:start <= composite_id and
composite_id < :end
order by
composite_id
"#;
/// Lists the specified recordings in ascending order by start time, passing them to a supplied
/// function. Given that the function is called with the database lock held, it should be quick.
pub(crate) fn list_recordings_by_time(
conn: &rusqlite::Connection,
stream_id: i32,
desired_time: Range<recording::Time>,
end_recording_id: i32,
f: &mut dyn FnMut(db::ListRecordingsRow) -> Result<(), base::Error>,
) -> Result<(), base::Error> {
let mut stmt = conn
.prepare_cached(LIST_RECORDINGS_BY_TIME_SQL)
.err_kind(ErrorKind::Internal)?;
let rows = stmt
.query(named_params! {
":stream_id": stream_id,
":start_time_90k": desired_time.start.0,
":end_time_90k": desired_time.end.0,
":end_composite_id": CompositeId::new(stream_id, end_recording_id).0,
})
.err_kind(ErrorKind::Internal)?;
list_recordings_inner(rows, false, f)
}
/// Lists the specified recordings in ascending order by id.
pub(crate) fn list_recordings_by_id(
conn: &rusqlite::Connection,
stream_id: i32,
desired_ids: Range<i32>,
f: &mut dyn FnMut(db::ListRecordingsRow) -> Result<(), base::Error>,
) -> Result<(), base::Error> {
let mut stmt = conn
.prepare_cached(LIST_RECORDINGS_BY_ID_SQL)
.err_kind(ErrorKind::Internal)?;
let rows = stmt
.query(named_params! {
":start": CompositeId::new(stream_id, desired_ids.start).0,
":end": CompositeId::new(stream_id, desired_ids.end).0,
})
.err_kind(ErrorKind::Internal)?;
list_recordings_inner(rows, true, f)
}
fn list_recordings_inner(
mut rows: rusqlite::Rows,
include_prev: bool,
f: &mut dyn FnMut(db::ListRecordingsRow) -> Result<(), base::Error>,
) -> Result<(), base::Error> {
while let Some(row) = rows.next().err_kind(ErrorKind::Internal)? {
let wall_duration_90k = row.get(4).err_kind(ErrorKind::Internal)?;
let media_duration_delta_90k: i32 = row.get(5).err_kind(ErrorKind::Internal)?;
f(db::ListRecordingsRow {
id: CompositeId(row.get(0).err_kind(ErrorKind::Internal)?),
run_offset: row.get(1).err_kind(ErrorKind::Internal)?,
flags: db::RecordingFlags::from_bits_retain(row.get(2).err_kind(ErrorKind::Internal)?),
start: recording::Time(row.get(3).err_kind(ErrorKind::Internal)?),
wall_duration_90k,
media_duration_90k: wall_duration_90k + media_duration_delta_90k,
sample_file_bytes: row.get(6).err_kind(ErrorKind::Internal)?,
video_samples: row.get(7).err_kind(ErrorKind::Internal)?,
video_sync_samples: row.get(8).err_kind(ErrorKind::Internal)?,
video_sample_entry_id: row.get(9).err_kind(ErrorKind::Internal)?,
open_id: row.get(10).err_kind(ErrorKind::Internal)?,
end_reason: row.get(11).err_kind(ErrorKind::Internal)?,
prev_media_duration_and_runs: match include_prev {
false => None,
true => Some((
recording::Duration(row.get(12).err_kind(ErrorKind::Internal)?),
row.get(13).err_kind(ErrorKind::Internal)?,
)),
},
recent_recording: None,
})?;
}
Ok(())
}
pub(crate) fn read_meta(conn: &rusqlite::Connection) -> Result<(Uuid, GlobalConfig), Error> {
Ok(conn.query_row(
"select uuid, config from meta",
params![],
|row| -> rusqlite::Result<(Uuid, GlobalConfig)> {
let uuid: SqlUuid = row.get(0)?;
let config: GlobalConfig = row.get(1)?;
Ok((uuid.0, config))
},
)?)
}
/// Inserts the specified recordings (for from `flush` only).
pub(crate) fn insert_recordings(
tx: &rusqlite::Transaction,
o: &db::Open,
new_recordings: &[(i32, db::RecentRecording)],
) -> Result<(), Error> {
if new_recordings.is_empty() {
return Ok(());
}
let mut stmt = tx.prepare_cached(
r#"
insert into recording (composite_id, stream_id, open_id, run_offset, flags,
sample_file_bytes, start_time_90k, prev_media_duration_90k,
prev_runs, wall_duration_90k, media_duration_delta_90k,
video_samples, video_sync_samples, video_sample_entry_id,
end_reason)
values (:composite_id, :stream_id, :open_id, :run_offset, :flags,
:sample_file_bytes, :start_time_90k, :prev_media_duration_90k,
:prev_runs, :wall_duration_90k, :media_duration_delta_90k,
:video_samples, :video_sync_samples, :video_sample_entry_id,
:end_reason)
"#,
)?;
let mut stmt_integrity = tx.prepare_cached(
r#"
insert into recording_integrity (composite_id, local_time_delta_90k,
sample_file_blake3)
values (:composite_id, :local_time_delta_90k,
:sample_file_blake3)
"#,
)?;
let mut stmt_playback = tx.prepare_cached(
r#"
insert into recording_playback (composite_id, video_index)
values (:composite_id, :video_index)
"#,
)?;
for &(stream_id, ref r) in new_recordings {
let id = CompositeId::new(stream_id, r.id);
assert!(
r.flags
& (RecordingFlags::GROWING | RecordingFlags::DELETED | RecordingFlags::UNCOMMITTED)
== RecordingFlags::UNCOMMITTED,
"insert_recording with bad state: {r:#?}",
);
stmt.execute(named_params! {
":composite_id": id.0,
":stream_id": i64::from(stream_id),
":open_id": o.id,
":run_offset": r.run_offset,
":flags": r.flags.difference(RecordingFlags::UNCOMMITTED).bits(),
":sample_file_bytes": r.sample_file_bytes,
":start_time_90k": r.start.0,
":wall_duration_90k": r.wall_duration_90k,
":media_duration_delta_90k": r.media_duration_90k - r.wall_duration_90k,
":prev_media_duration_90k": r.prev_media_duration.0,
":prev_runs": r.prev_runs,
":video_samples": r.video_samples,
":video_sync_samples": r.video_sync_samples,
":video_sample_entry_id": r.video_sample_entry_id,
":end_reason": r.end_reason.as_deref(),
})
.map_err(|e| {
err!(
e,
msg("unable to insert recording for stream {stream_id}: {r:#?}")
)
})?;
let blake3 = r.sample_file_blake3.as_ref().map(|b| &b[..]);
let delta = match r.run_offset {
0 => None,
_ => Some(r.local_time_delta.0),
};
stmt_integrity
.execute(named_params! {
":composite_id": id.0,
":local_time_delta_90k": delta,
":sample_file_blake3": blake3,
})
.map_err(|e| {
err!(
e,
msg("unable to insert recording_integrity for stream {stream_id}: {r:#?}")
)
})?;
stmt_playback
.execute(named_params! {
":composite_id": id.0,
":video_index": &r.video_index,
})
.map_err(|e| err!(e, msg("unable to insert recording_playback for {r:#?}")))?;
}
Ok(())
}
/// Transfers the given recording range from the `recording` and associated tables to the `garbage`
/// table. `sample_file_dir_id` is assumed to be correct.
///
/// Returns the number of recordings which were deleted.
pub(crate) fn delete_recordings(
tx: &rusqlite::Transaction,
sample_file_dir_id: i32,
ids: Range<CompositeId>,
) -> Result<usize, Error> {
let mut insert = tx.prepare_cached(
r#"
insert into garbage (sample_file_dir_id, composite_id)
select
:sample_file_dir_id,
composite_id
from
recording
where
:start <= composite_id and
composite_id < :end
"#,
)?;
let mut del_playback = tx.prepare_cached(
r#"
delete from recording_playback
where
:start <= composite_id and
composite_id < :end
"#,
)?;
let mut del_integrity = tx.prepare_cached(
r#"
delete from recording_integrity
where
:start <= composite_id and
composite_id < :end
"#,
)?;
let mut del_main = tx.prepare_cached(
r#"
delete from recording
where
:start <= composite_id and
composite_id < :end
"#,
)?;
let n = insert.execute(named_params! {
":sample_file_dir_id": sample_file_dir_id,
":start": ids.start.0,
":end": ids.end.0,
})?;
let p = named_params! {
":start": ids.start.0,
":end": ids.end.0,
};
let n_playback = del_playback.execute(p)?;
if n_playback != n {
bail!(
Internal,
msg(
"inserted {} garbage rows but deleted {} recording_playback rows!",
n,
n_playback
),
);
}
let n_integrity = del_integrity.execute(p)?;
if n_integrity > n {
// fewer is okay; recording_integrity is optional.
bail!(
Internal,
msg(
"inserted {} garbage rows but deleted {} recording_integrity rows!",
n,
n_integrity
),
);
}
let n_main = del_main.execute(p)?;
if n_main != n {
bail!(
Internal,
msg("inserted {n} garbage rows but deleted {n_main} recording rows!"),
);
}
Ok(n)
}
/// Marks the given sample files as deleted. This shouldn't be called until the files have
/// been `unlink()`ed and the parent directory `fsync()`ed.
pub(crate) fn mark_sample_files_deleted(
tx: &rusqlite::Transaction,
ids: &[CompositeId],
) -> Result<(), Error> {
if ids.is_empty() {
return Ok(());
}
let mut stmt = tx.prepare_cached("delete from garbage where composite_id = ?")?;
for &id in ids {
let changes = stmt.execute(params![id.0])?;
if changes != 1 {
// panic rather than return error. Errors get retried indefinitely, but there's no
// recovery from this condition.
//
// Tempting to just consider logging error and moving on, but this represents a logic
// flaw, so complain loudly. The freshly deleted file might still be referenced in the
// recording table.
panic!("no garbage row for {id}");
}
}
Ok(())
}
/// Gets the time range of recordings for the given stream.
pub(crate) fn get_range(
conn: &rusqlite::Connection,
stream_id: i32,
) -> Result<Option<Range<recording::Time>>, Error> {
// The minimum is straightforward, taking advantage of the start_time_90k index.
let mut stmt = conn.prepare_cached(STREAM_MIN_START_SQL)?;
let mut rows = stmt.query(named_params! {":stream_id": stream_id})?;
let min_start = match rows.next()? {
Some(row) => recording::Time(row.get(0)?),
None => return Ok(None),
};
// There was a minimum, so there should be a maximum too. Calculating it is less
// straightforward because recordings could overlap. All recordings starting in the
// last MAX_RECORDING_DURATION must be examined in order to take advantage of the
// start_time_90k index.
let mut stmt = conn.prepare_cached(STREAM_MAX_START_SQL)?;
let mut rows = stmt.query(named_params! {":stream_id": stream_id})?;
let mut maxes_opt = None;
while let Some(row) = rows.next()? {
let row_start = recording::Time(row.get(0)?);
let row_duration: i64 = row.get(1)?;
let row_end = recording::Time(row_start.0 + row_duration);
let maxes = match maxes_opt {
None => row_start..row_end,
Some(Range { start: s, end: e }) => s..::std::cmp::max(e, row_end),
};
if row_start.0 <= maxes.start.0 - recording::MAX_RECORDING_WALL_DURATION {
break;
}
maxes_opt = Some(maxes);
}
let max_end = match maxes_opt {
Some(Range { start: _, end: e }) => e,
None => bail!(
Internal,
msg("missing max for stream {stream_id} which had min {min_start}"),
),
};
Ok(Some(min_start..max_end))
}
/// Lists all garbage ids for the given sample file directory.
pub(crate) fn list_garbage(
conn: &rusqlite::Connection,
dir_id: i32,
) -> Result<FastHashSet<CompositeId>, Error> {
let mut garbage = FastHashSet::default();
let mut stmt =
conn.prepare_cached("select composite_id from garbage where sample_file_dir_id = ?")?;
let mut rows = stmt.query([&dir_id])?;
while let Some(row) = rows.next()? {
garbage.insert(CompositeId(row.get(0)?));
}
Ok(garbage)
}
/// Lists the oldest recordings for a stream, starting with the given id.
/// `f` should return true as long as further rows are desired.
pub(crate) fn list_oldest_recordings(
conn: &rusqlite::Connection,
start: CompositeId,
f: &mut dyn FnMut(db::ListOldestRecordingsRow) -> bool,
) -> Result<(), Error> {
let mut stmt = conn.prepare_cached(LIST_OLDEST_RECORDINGS_SQL)?;
let mut rows = stmt.query(named_params! {
":start": start.0,
":end": CompositeId::new(start.stream() + 1, 0).0,
})?;
while let Some(row) = rows.next()? {
let should_continue = f(db::ListOldestRecordingsRow {
id: CompositeId(row.get(0)?),
start: recording::Time(row.get(1)?),
wall_duration_90k: row.get(2)?,
sample_file_bytes: row.get(3)?,
});
if !should_continue {
break;
}
}
Ok(())
}