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denoland-deno/core/examples/http_bench_json_ops.rs
Luca Casonato 3b6b75bb46
feat(core): improve resource read & write traits (#16115)
This commit introduces two new buffer wrapper types to `deno_core`. The
main benefit of these new wrappers is that they can wrap a number of
different underlying buffer types. This allows for a more flexible read
and write API on resources that will require less copying of data
between different buffer representations.

- `BufView` is a read-only view onto a buffer. It can be backed by
`ZeroCopyBuf`, `Vec<u8>`, and `bytes::Bytes`.
- `BufViewMut` is a read-write view onto a buffer. It can be cheaply
converted into a `BufView`. It can be backed by `ZeroCopyBuf` or
`Vec<u8>`.

Both new buffer views have a cursor. This means that the start point of
the view can be constrained to write / read from just a slice of the
view. Only the start point of the slice can be adjusted. The end point
is fixed. To adjust the end point, the underlying buffer needs to be
truncated.

Readable resources have been changed to better cater to resources that
do not support BYOB reads. The basic `read` method now returns a
`BufView` instead of taking a `ZeroCopyBuf` to fill. This allows the
operation to return buffers that the resource has already allocated,
instead of forcing the caller to allocate the buffer. BYOB reads are
still very useful for resources that support them, so a new `read_byob`
method has been added that takes a `BufViewMut` to fill. `op_read`
attempts to use `read_byob` if the resource supports it, which falls
back to `read` and performs an additional copy if it does not. For
Rust->JS reads this change should have no impact, but for Rust->Rust
reads, this allows the caller to avoid an additional copy in many
scenarios. This combined with the support for `BufView` to be backed by
`bytes::Bytes` allows us to avoid one data copy when piping from a
`fetch` response into an `ext/http` response.

Writable resources have been changed to take a `BufView` instead of a
`ZeroCopyBuf` as an argument. This allows for less copying of data in
certain scenarios, as described above. Additionally a new
`Resource::write_all` method has been added that takes a `BufView` and
continually attempts to write the resource until the entire buffer has
been written. Certain resources like files can override this method to
provide a more efficient `write_all` implementation.
2022-10-09 14:49:25 +00:00

182 lines
4.7 KiB
Rust

// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
use deno_core::anyhow::Error;
use deno_core::op;
use deno_core::AsyncRefCell;
use deno_core::AsyncResult;
use deno_core::CancelHandle;
use deno_core::CancelTryFuture;
use deno_core::JsRuntime;
use deno_core::OpState;
use deno_core::RcRef;
use deno_core::Resource;
use deno_core::ResourceId;
use std::cell::RefCell;
use std::env;
use std::net::SocketAddr;
use std::rc::Rc;
use tokio::io::AsyncReadExt;
use tokio::io::AsyncWriteExt;
// This is a hack to make the `#[op]` macro work with
// deno_core examples.
// You can remove this:
use deno_core::*;
struct Logger;
impl log::Log for Logger {
fn enabled(&self, metadata: &log::Metadata) -> bool {
metadata.level() <= log::max_level()
}
fn log(&self, record: &log::Record) {
if self.enabled(record.metadata()) {
println!("{} - {}", record.level(), record.args());
}
}
fn flush(&self) {}
}
// Note: a `tokio::net::TcpListener` doesn't need to be wrapped in a cell,
// because it only supports one op (`accept`) which does not require a mutable
// reference to the listener.
struct TcpListener {
inner: tokio::net::TcpListener,
cancel: CancelHandle,
}
impl TcpListener {
async fn accept(self: Rc<Self>) -> Result<TcpStream, std::io::Error> {
let cancel = RcRef::map(&self, |r| &r.cancel);
let stream = self.inner.accept().try_or_cancel(cancel).await?.0.into();
Ok(stream)
}
}
impl Resource for TcpListener {
fn close(self: Rc<Self>) {
self.cancel.cancel();
}
}
impl TryFrom<std::net::TcpListener> for TcpListener {
type Error = std::io::Error;
fn try_from(
std_listener: std::net::TcpListener,
) -> Result<Self, Self::Error> {
tokio::net::TcpListener::try_from(std_listener).map(|tokio_listener| Self {
inner: tokio_listener,
cancel: Default::default(),
})
}
}
struct TcpStream {
rd: AsyncRefCell<tokio::net::tcp::OwnedReadHalf>,
wr: AsyncRefCell<tokio::net::tcp::OwnedWriteHalf>,
// When a `TcpStream` resource is closed, all pending 'read' ops are
// canceled, while 'write' ops are allowed to complete. Therefore only
// 'read' futures are attached to this cancel handle.
cancel: CancelHandle,
}
impl TcpStream {
async fn read(self: Rc<Self>, data: &mut [u8]) -> Result<usize, Error> {
let mut rd = RcRef::map(&self, |r| &r.rd).borrow_mut().await;
let cancel = RcRef::map(self, |r| &r.cancel);
let nread = rd.read(data).try_or_cancel(cancel).await?;
Ok(nread)
}
async fn write(self: Rc<Self>, data: &[u8]) -> Result<usize, Error> {
let mut wr = RcRef::map(self, |r| &r.wr).borrow_mut().await;
let nwritten = wr.write(data).await?;
Ok(nwritten)
}
}
impl Resource for TcpStream {
deno_core::impl_readable_byob!();
deno_core::impl_writable!();
fn close(self: Rc<Self>) {
self.cancel.cancel()
}
}
impl From<tokio::net::TcpStream> for TcpStream {
fn from(s: tokio::net::TcpStream) -> Self {
let (rd, wr) = s.into_split();
Self {
rd: rd.into(),
wr: wr.into(),
cancel: Default::default(),
}
}
}
fn create_js_runtime() -> JsRuntime {
let ext = deno_core::Extension::builder()
.ops(vec![op_listen::decl(), op_accept::decl()])
.build();
JsRuntime::new(deno_core::RuntimeOptions {
extensions: vec![ext],
..Default::default()
})
}
#[op]
fn op_listen(state: &mut OpState) -> Result<ResourceId, Error> {
log::debug!("listen");
let addr = "127.0.0.1:4544".parse::<SocketAddr>().unwrap();
let std_listener = std::net::TcpListener::bind(&addr)?;
std_listener.set_nonblocking(true)?;
let listener = TcpListener::try_from(std_listener)?;
let rid = state.resource_table.add(listener);
Ok(rid)
}
#[op]
async fn op_accept(
state: Rc<RefCell<OpState>>,
rid: ResourceId,
) -> Result<ResourceId, Error> {
log::debug!("accept rid={}", rid);
let listener = state.borrow().resource_table.get::<TcpListener>(rid)?;
let stream = listener.accept().await?;
let rid = state.borrow_mut().resource_table.add(stream);
Ok(rid)
}
fn main() {
log::set_logger(&Logger).unwrap();
log::set_max_level(
env::args()
.find(|a| a == "-D")
.map(|_| log::LevelFilter::Debug)
.unwrap_or(log::LevelFilter::Warn),
);
// NOTE: `--help` arg will display V8 help and exit
deno_core::v8_set_flags(env::args().collect());
let mut js_runtime = create_js_runtime();
let runtime = tokio::runtime::Builder::new_current_thread()
.enable_all()
.build()
.unwrap();
let future = async move {
js_runtime
.execute_script(
"http_bench_json_ops.js",
include_str!("http_bench_json_ops.js"),
)
.unwrap();
js_runtime.run_event_loop(false).await
};
runtime.block_on(future).unwrap();
}