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denoland-deno/ext/net/io.rs
Aaron O'Mullan 375ce63c63
feat(core): streams (#12596)
This allows resources to be "streams" by implementing read/write/shutdown. These streams are implicit since their nature (read/write/duplex) isn't known until called, but we could easily add another method to explicitly tag resources as streams.

`op_read/op_write/op_shutdown` are now builtin ops provided by `deno_core`

Note: this current implementation is simple & straightforward but it results in an additional alloc per read/write call

Closes #12556
2021-11-09 19:26:17 +01:00

170 lines
3.9 KiB
Rust

// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
use deno_core::error::AnyError;
use deno_core::AsyncMutFuture;
use deno_core::AsyncRefCell;
use deno_core::AsyncResult;
use deno_core::CancelHandle;
use deno_core::CancelTryFuture;
use deno_core::RcRef;
use deno_core::Resource;
use deno_core::ZeroCopyBuf;
use std::borrow::Cow;
use std::rc::Rc;
use tokio::io::AsyncRead;
use tokio::io::AsyncReadExt;
use tokio::io::AsyncWrite;
use tokio::io::AsyncWriteExt;
use tokio::net::tcp;
#[cfg(unix)]
use tokio::net::unix;
/// A full duplex resource has a read and write ends that are completely
/// independent, like TCP/Unix sockets and TLS streams.
#[derive(Debug)]
pub struct FullDuplexResource<R, W> {
rd: AsyncRefCell<R>,
wr: AsyncRefCell<W>,
// When a full-duplex resource is closed, all pending 'read' ops are
// canceled, while 'write' ops are allowed to complete. Therefore only
// 'read' futures should be attached to this cancel handle.
cancel_handle: CancelHandle,
}
impl<R, W> FullDuplexResource<R, W>
where
R: AsyncRead + Unpin + 'static,
W: AsyncWrite + Unpin + 'static,
{
pub fn new((rd, wr): (R, W)) -> Self {
Self {
rd: rd.into(),
wr: wr.into(),
cancel_handle: Default::default(),
}
}
pub fn into_inner(self) -> (R, W) {
(self.rd.into_inner(), self.wr.into_inner())
}
pub fn rd_borrow_mut(self: &Rc<Self>) -> AsyncMutFuture<R> {
RcRef::map(self, |r| &r.rd).borrow_mut()
}
pub fn wr_borrow_mut(self: &Rc<Self>) -> AsyncMutFuture<W> {
RcRef::map(self, |r| &r.wr).borrow_mut()
}
pub fn cancel_handle(self: &Rc<Self>) -> RcRef<CancelHandle> {
RcRef::map(self, |r| &r.cancel_handle)
}
pub fn cancel_read_ops(&self) {
self.cancel_handle.cancel()
}
pub async fn read(
self: Rc<Self>,
mut buf: ZeroCopyBuf,
) -> Result<usize, AnyError> {
let mut rd = self.rd_borrow_mut().await;
let nread = rd
.read(&mut buf)
.try_or_cancel(self.cancel_handle())
.await?;
Ok(nread)
}
pub async fn write(
self: Rc<Self>,
buf: ZeroCopyBuf,
) -> Result<usize, AnyError> {
let mut wr = self.wr_borrow_mut().await;
let nwritten = wr.write(&buf).await?;
Ok(nwritten)
}
pub async fn shutdown(self: Rc<Self>) -> Result<(), AnyError> {
let mut wr = self.wr_borrow_mut().await;
wr.shutdown().await?;
Ok(())
}
}
pub type TcpStreamResource =
FullDuplexResource<tcp::OwnedReadHalf, tcp::OwnedWriteHalf>;
impl Resource for TcpStreamResource {
fn name(&self) -> Cow<str> {
"tcpStream".into()
}
fn read(self: Rc<Self>, buf: ZeroCopyBuf) -> AsyncResult<usize> {
Box::pin(self.read(buf))
}
fn write(self: Rc<Self>, buf: ZeroCopyBuf) -> AsyncResult<usize> {
Box::pin(self.write(buf))
}
fn shutdown(self: Rc<Self>) -> AsyncResult<()> {
Box::pin(self.shutdown())
}
fn close(self: Rc<Self>) {
self.cancel_read_ops();
}
}
#[cfg(unix)]
pub type UnixStreamResource =
FullDuplexResource<unix::OwnedReadHalf, unix::OwnedWriteHalf>;
#[cfg(not(unix))]
pub struct UnixStreamResource;
#[cfg(not(unix))]
impl UnixStreamResource {
pub async fn read(
self: Rc<Self>,
_buf: ZeroCopyBuf,
) -> Result<usize, AnyError> {
unreachable!()
}
pub async fn write(
self: Rc<Self>,
_buf: ZeroCopyBuf,
) -> Result<usize, AnyError> {
unreachable!()
}
pub async fn shutdown(self: Rc<Self>) -> Result<(), AnyError> {
unreachable!()
}
pub fn cancel_read_ops(&self) {
unreachable!()
}
}
impl Resource for UnixStreamResource {
fn name(&self) -> Cow<str> {
"unixStream".into()
}
fn read(self: Rc<Self>, buf: ZeroCopyBuf) -> AsyncResult<usize> {
Box::pin(self.read(buf))
}
fn write(self: Rc<Self>, buf: ZeroCopyBuf) -> AsyncResult<usize> {
Box::pin(self.write(buf))
}
fn shutdown(self: Rc<Self>) -> AsyncResult<()> {
Box::pin(self.shutdown())
}
fn close(self: Rc<Self>) {
self.cancel_read_ops();
}
}