This PR implements a custom scheduler for audio threads, which reduces thread use and (often) memory consumption.
To save threads and memory (e.g., packet buffer allocations), Songbird parks Mixer tasks which do not have any live Tracks.
These are now all co-located on a single async 'Idle' task.
This task is responsible for managing UDP keepalive messages for each task, maintaining event state, and executing any Mixer task messages.
Whenever any message arrives which adds a `Track`, the mixer task is moved to a live thread.
The Idle task inspects task counts and execution time on each thread, choosing the first live thread with room, and creating a new one if needed.
Each live thread is responsible for running as many live mixers as it can in a single tick every 20ms: this currently defaults to 16 mixers per thread, but is user-configurable.
A live thread also stores RTP packet blocks to be written into by each sub-task.
Each live thread has a conservative limit of 18ms that it will aim to stay under: if all work takes longer than this, it will offload the task with the highest mixing cost once per tick onto another (possibly new) live worker thread.
Adds the "receive" feature, which is disabled by default. When this is disabled, the UDP receive task is not compiled and not run, and as an optimisation the UDP receive buffer size is set to 0. All related events are also removed.
This also removes the UDP Tx task, and moves packet and keepalive sends back into the mixer thread. This allows us to entirely remove channels and various allocations between the mixer and an async task created only for sending data (i.e., fewer memcopies).
If "receive" is enabled, UDP sends are now non-blocking due to technical constraints -- failure to send is non-fatal, but *will* drop affected packets. Given that blocking on a UDP send indicates that the OS cannot clear send buffers fast enough, this should alleviate OS load.
Closes#131.
All dependencies have been moved to the new "dep:x" and "x?/feature" syntax to remove the bloat from the docs.rs/crates.io/lib.rs feature panes.
Accordingly, this lets us break "rustls" and "native" out from annoying hybrids like "serenity-rustls" or "twilight-native" -- specify your library and your backend, and it should just work.
The complete list of features is now: driver, gateway, serenity, twilight, rustls, native, builtin-queue, simd-json, internals (plus "default" and "full-doc").
This PR adds support for the simd-json library whenever decoding or encoding JSON responses. This may be enabled independently of serenity and twilight support for SIMD acceleration.
Co-authored-by: Kyle Simpson <kyleandrew.simpson@gmail.com>
This extensive PR rewrites the internal mixing logic of the driver to use symphonia for parsing and decoding audio data, and rubato to resample audio. Existing logic to decode DCA and Opus formats/data have been reworked as plugins for symphonia. The main benefit is that we no longer need to keep yt-dlp and ffmpeg processes alive, saving a lot of memory and CPU: all decoding can be done in Rust! In exchange, we now need to do a lot of the HTTP handling and resumption ourselves, but this is still a huge net positive.
`Input`s have been completely reworked such that all default (non-cached) sources are lazy by default, and are no longer covered by a special-case `Restartable`. These now span a gamut from a `Compose` (lazy), to a live source, to a fully `Parsed` source. As mixing is still sync, this includes adapters for `AsyncRead`/`AsyncSeek`, and HTTP streams.
`Track`s have been reworked so that they only contain initialisation state for each track. `TrackHandles` are only created once a `Track`/`Input` has been handed over to the driver, replacing `create_player` and related functions. `TrackHandle::action` now acts on a `View` of (im)mutable state, and can request seeks/readying via `Action`.
Per-track event handling has also been improved -- we can now determine and propagate the reason behind individual track errors due to the new backend. Some `TrackHandle` commands (seek etc.) benefit from this, and now use internal callbacks to signal completion.
Due to associated PRs on felixmcfelix/songbird from avid testers, this includes general clippy tweaks, API additions, and other repo-wide cleanup. Thanks go out to the below co-authors.
Co-authored-by: Gnome! <45660393+GnomedDev@users.noreply.github.com>
Co-authored-by: Alakh <36898190+alakhpc@users.noreply.github.com>
This is a simple organisational change which moves `crate::Bitrate` to `crate::driver::Bitrate` to slightly clean up the crate root.
This has been tested using `cargo make ready`.
This change fixes tasks hanging due to rare cases of messages being lost between full Discord reconnections by placing a configurable timeout on the `ConnectionInfo` responses. This is a companion fix to [serenity#1255](https://github.com/serenity-rs/serenity/pull/1255). To make this doable, `Config`s are now used by all versions of `Songbird`/`Call`, and relevant functions are added to simplify setup with configuration. These are now non-exhaustive, correcting an earlier oversight. For future extensibility, this PR moves the return type of `join`/`join_gateway` into a custom future (no longer leaking flume's `RecvFut` type).
Additionally, this fixes the Makefile's feature sets for driver/gateway-only compilation.
This is a breaking change in:
* the return types of `join`/`join_gateway`
* moving `crate::driver::Config` -> `crate::Config`,
* `Config` and `JoinError` becoming `#[non_breaking]`.
This was tested via `cargo make ready`, and by testing `examples/serenity/voice_receive` with various timeout settings.
Adds support to the library for tokio 0.2 backward-compatibility. This should hopefully benefit, and prevent lavalink-rs from being blocked on this feature.
These can be reached using, e.g., `gateway-tokio-02`, `driver-tokio-02`, `serenity-rustls-tokio-02`, and `serenity-native-tokio-02` features.
Naturally, this requires some jiggering about with features and the underlying CI, which has been taken care of. Twilight can't be handled in this way, as their last tokio 0.2 version uses the deprecated Discord Gateway v6.
Adds a shared TypeMap per TrackHandle. This should greatly simplify the user experience for attaching additional per-track state which the driver does not care for.
Main goal: a lot of nested future/result folding.
This mainly modifies error handling for Tracks and TrackHandles to be
more consistent, and hides the underlying channel result passing in
get_info. Errors returned should be far clearer, and are domain
specific rather than falling back to a very opaque use of the underlying
channel error. It should be clearer to users why their handle commands
failed, or why they can't make a ytdl track loop or similar.
Also fixed/cleaned up Songbird::join(_gateway) to return in a single
await, sparing the user from the underlying channel details and repeated
Errs. I was trying for some time to extend the same graces to `Call`,
but could not figure out a sane way to get a 'static version of the
first future in the chain (i.e., the gateway send) so that the whole
thing could happen after dropping the lock around the Call. I really
wanted to fix this to happen as a single folded await too, but I think
this might need some crazy hack or redesign.
Far cleaner and more reliable than the old doc-link pattern. Also allowed me to spot some event types and sources which should have been made non_exhaustive.
This implements a proof-of-concept for an improved audio frontend. The largest change is the introduction of events and event handling: both by time elapsed and by track events, such as ending or looping. Following on from this, the library now includes a basic, event-driven track queue system (which people seem to ask for unusually often). A new sample, `examples/13_voice_events`, demonstrates both the `TrackQueue` system and some basic events via the `~queue` and `~play_fade` commands.
Locks are removed from around the control of `Audio` objects, which should allow the backend to be moved to a more granular futures-based backend solution in a cleaner way.
