proxmox-backup/src/client/pipe_to_stream.rs

66 lines
2.0 KiB
Rust

// Implement simple flow control for h2 client
//
// See also: hyper/src/proto/h2/mod.rs
use failure::*;
use futures::{try_ready, Async, Future, Poll};
use h2::{SendStream};
use bytes::Bytes;
pub struct PipeToSendStream {
body_tx: SendStream<Bytes>,
data: Option<Bytes>,
}
impl PipeToSendStream {
pub fn new(data: Bytes, tx: SendStream<Bytes>) -> PipeToSendStream {
PipeToSendStream {
body_tx: tx,
data: Some(data),
}
}
}
impl Future for PipeToSendStream {
type Item = ();
type Error = Error;
fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
loop {
if self.data != None {
// just reserve 1 byte to make sure there's some
// capacity available. h2 will handle the capacity
// management for the actual body chunk.
self.body_tx.reserve_capacity(1);
if self.body_tx.capacity() == 0 {
loop {
match try_ready!(self.body_tx.poll_capacity().map_err(Error::from)) {
Some(0) => {}
Some(_) => break,
None => return Err(format_err!("protocol canceled")),
}
}
} else {
if let Async::Ready(reason) = self.body_tx.poll_reset().map_err(Error::from)? {
return Err(format_err!("stream received RST_STREAM: {:?}", reason));
}
}
self.body_tx
.send_data(self.data.take().unwrap(), true)
.map_err(Error::from)?;
return Ok(Async::Ready(()));
} else {
if let Async::Ready(reason) = self.body_tx.poll_reset().map_err(Error::from)? {
return Err(format_err!("stream received RST_STREAM: {:?}", reason));
}
return Ok(Async::Ready(()));
}
}
}
}