Although Tokio is extremely powerful, somme of its features have been less than intuitive to me. So I built this crate to simplify interracting with Tokio in the ways that I usually do:
This API should only be used from inside a Tokio Runtime: it will try to spawn Tokio Tasks and will thus panic if it's not the case.
rust
fn tokio_main() {
let (sink, stream) = LineCodec.framed(tcp_stream).split();
let io = IoManagerBuilder::new(sink, stream).build();
let writer = io.get_writer();
io.subscribe(move |frame| {
writer.write(frame);
});
io.subscribe(move |frame| {
println!("{}", frame);
})
}
You can use filters to have your callbacks only be called when the frame matches some criterion.
rust
fn tokio_main() {
let (sink, stream) = LineCodec.framed(tcp_stream).split();
let io = IoManagerBuilder::new(sink, stream).with_filter(|frame, writer| {
if frame.to_ascii_lowercase().contains("hello there") {
writer.write("General Kenobi!");
return None;
}
Some(frame)
}).build();
let writer = io.get_writer();
io.subscribe(move |frame| {
writer.write(frame);
});
io.subscribe(move |frame| {
println!("{}", frame);
})
}
Every time you use subscribe(callback), you endure the cost of one more futures::sync::mpsc::channel,
and of one frame.clone() per callback call.
It's not a high cost, but if you only have one callback, you can cut these costs by passing your callback
as a filter that always returns None.
rust
fn tokio_main() {
let (sink, stream) = LineCodec.framed(tcp_stream).split();
let io = IoManagerBuilder::new(sink, stream).with_filter(|frame, writer| {
writer.write(frame);
None
});
}
By default, IoManager will ignore errors on the assigned Stream. If you wish to handle errors, you can specify a function
for error handling by passing it to the builder using with_error_handler().
rust
fn tokio_main() {
let (sink, stream) = LineCodec.framed(tcp_stream).split();
let io = IoManagerBuilder::new(sink, stream)
.with_filter(|frame, writer| {
if frame.to_ascii_lowercase().contains("hello there") {
writer.write("General Kenobi!");
return None;
}
Some(frame)
})
.with_error_handler(move |error| {
println!("{}", error);
})
.build();
let writer = io.get_writer();
io.subscribe(move |frame| {
writer.write(frame);
});
io.subscribe(move |frame| {
println!("{}", frame);
})
}