use async_io::Timer;
use std::time::Duration;
use std::time::Instant;
use crate::anyhow::Result;
use crate::runtime::Block;
use crate::runtime::BlockMeta;
use crate::runtime::BlockMetaBuilder;
use crate::runtime::Kernel;
use crate::runtime::MessageIo;
use crate::runtime::MessageIoBuilder;
use crate::runtime::Pmt;
use crate::runtime::StreamIo;
use crate::runtime::StreamIoBuilder;
use crate::runtime::WorkIo;
pub struct MessageSource {
message: Pmt,
interval: Duration,
t_last: Instant,
n_messages: Option<usize>,
}
impl MessageSource {
pub fn new(message: Pmt, interval: Duration, n_messages: Option<usize>) -> Block {
Block::new(
BlockMetaBuilder::new("MessageSource").build(),
StreamIoBuilder::new().build(),
MessageIoBuilder::new().add_output("out").build(),
MessageSource {
message,
interval,
t_last: Instant::now(),
n_messages,
},
)
}
async fn sleep(dur: Duration) {
Timer::after(dur).await;
}
}
#[doc(hidden)]
#[async_trait]
impl Kernel for MessageSource {
async fn work(
&mut self,
io: &mut WorkIo,
_sio: &mut StreamIo,
mio: &mut MessageIo<Self>,
_b: &mut BlockMeta,
) -> Result<()> {
let now = Instant::now();
if now >= self.t_last + self.interval {
mio.post(0, self.message.clone()).await;
self.t_last = now;
if let Some(ref mut n) = self.n_messages {
*n -= 1;
if *n == 0 {
io.finished = true;
}
}
}
io.block_on(MessageSource::sleep(
self.t_last + self.interval - Instant::now(),
));
Ok(())
}
async fn init(
&mut self,
_sio: &mut StreamIo,
_mio: &mut MessageIo<Self>,
_b: &mut BlockMeta,
) -> Result<()> {
self.t_last = Instant::now();
Ok(())
}
}
#[cfg_attr(docsrs, doc(cfg(not(target_arch = "wasm32"))))]
pub struct MessageSourceBuilder {
message: Pmt,
duration: Duration,
n_messages: Option<usize>,
}
impl MessageSourceBuilder {
pub fn new(message: Pmt, duration: Duration) -> MessageSourceBuilder {
MessageSourceBuilder {
message,
duration,
n_messages: None,
}
}
#[must_use]
pub fn n_messages(mut self, n: usize) -> MessageSourceBuilder {
self.n_messages = Some(n);
self
}
pub fn build(self) -> Block {
MessageSource::new(self.message, self.duration, self.n_messages)
}
}