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::StreamIo;
use crate::runtime::StreamIoBuilder;
use crate::runtime::WorkIo;
pub struct NullSource<T: Send + 'static> {
_type: std::marker::PhantomData<T>,
}
impl<T: Send + 'static> NullSource<T> {
pub fn new() -> Block {
Block::new(
BlockMetaBuilder::new("NullSource").build(),
StreamIoBuilder::new()
.add_output("out", std::mem::size_of::<T>())
.build(),
MessageIoBuilder::new().build(),
NullSource::<T> {
_type: std::marker::PhantomData,
},
)
}
}
#[doc(hidden)]
#[async_trait]
impl<T: Send + 'static> Kernel for NullSource<T> {
async fn work(
&mut self,
_io: &mut WorkIo,
sio: &mut StreamIo,
_mio: &mut MessageIo<Self>,
_meta: &mut BlockMeta,
) -> Result<()> {
let o = sio.output(0).slice::<u8>();
debug_assert_eq!(0, o.len() % std::mem::size_of::<T>());
unsafe {
std::ptr::write_bytes(o.as_mut_ptr(), 0, o.len());
}
sio.output(0).produce(o.len() / std::mem::size_of::<T>());
Ok(())
}
}