This PR makes many of the types under `EventContext` separate `#[non_exhaustive]` structs. This makes it more feasible to add further information to connection and packet events as required in future. On this note, driver (re)connection events now include the SSRC supplied by Discord and the domain name which was connected to.
In addition, this fixes global timed events to return a list of all live tracks, and extensively details/documents events at a high level.
This was tested using `cargo make ready`.
* Driver Benchmarks
Benchmarks driver use cases for single packet send,
multiple packet send, float vs opus, and the cost of
head-of-queue track removal.
Mix costs for large packet counts are also included.
This is a prelude to the optimisations discussed in
#21.
* Typo in benchmark
* Place Opus packet directly into packet buffer
Cleans up some other logic surrounding this, too. Gets a 16.9% perf improvement on opus packet passthrough (sub 5us here).
* Better track removal
In theory this should be faster, but it aint. Keeping in case
reducing struct sizes down the line magically makes this
faster.
* Reduce size of Input, TrackHandle
Metadata is now boxed away. Similarly, TrackHandles are neatly Arc'd to reduce their size to pointer length (and mitigate the impact of copies if we add in more fields).
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.
