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

2 files changed, 22 insertions, 60 deletions

diff --git a/core/examples/http_bench_json_ops.js b/core/examples/http_bench_json_ops.js
index ad36dd674..12d79a0ce 100644
--- a/core/examples/http_bench_json_ops.js
+++ b/core/examples/http_bench_json_ops.js
@@ -19,28 +19,11 @@ function accept(serverRid) {
   return Deno.core.opAsync("accept", serverRid);
 }
 
-/**
- * Reads a packet from the rid, presumably an http request. data is ignored.
- * Returns bytes read.
- */
-function read(rid, data) {
-  return Deno.core.opAsync("read", rid, data);
-}
-
-/** Writes a fixed HTTP response to the socket rid. Returns bytes written. */
-function write(rid, data) {
-  return Deno.core.opAsync("write", rid, data);
-}
-
-function close(rid) {
-  Deno.core.opSync("close", rid);
-}
-
 async function serve(rid) {
   try {
     while (true) {
-      await read(rid, requestBuf);
-      await write(rid, responseBuf);
+      await Deno.core.read(rid, requestBuf);
+      await Deno.core.write(rid, responseBuf);
     }
   } catch (e) {
     if (
@@ -50,7 +33,7 @@ async function serve(rid) {
       throw e;
     }
   }
-  close(rid);
+  Deno.core.close(rid);
 }
 
 async function main() {
diff --git a/core/examples/http_bench_json_ops.rs b/core/examples/http_bench_json_ops.rs
index 749f40485..6f14f558c 100644
--- a/core/examples/http_bench_json_ops.rs
+++ b/core/examples/http_bench_json_ops.rs
@@ -1,6 +1,7 @@
 // Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.
 use deno_core::error::AnyError;
 use deno_core::AsyncRefCell;
+use deno_core::AsyncResult;
 use deno_core::CancelHandle;
 use deno_core::CancelTryFuture;
 use deno_core::JsRuntime;
@@ -77,19 +78,33 @@ struct TcpStream {
 }
 
 impl TcpStream {
-  async fn read(self: Rc<Self>, buf: &mut [u8]) -> Result<usize, Error> {
+  async fn read(
+    self: Rc<Self>,
+    mut buf: ZeroCopyBuf,
+  ) -> Result<usize, AnyError> {
     let mut rd = RcRef::map(&self, |r| &r.rd).borrow_mut().await;
     let cancel = RcRef::map(self, |r| &r.cancel);
-    rd.read(buf).try_or_cancel(cancel).await
+    rd.read(&mut buf)
+      .try_or_cancel(cancel)
+      .await
+      .map_err(AnyError::from)
   }
 
-  async fn write(self: Rc<Self>, buf: &[u8]) -> Result<usize, Error> {
+  async fn write(self: Rc<Self>, buf: ZeroCopyBuf) -> Result<usize, AnyError> {
     let mut wr = RcRef::map(self, |r| &r.wr).borrow_mut().await;
-    wr.write(buf).await
+    wr.write(&buf).await.map_err(AnyError::from)
   }
 }
 
 impl Resource for TcpStream {
+  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 close(self: Rc<Self>) {
     self.cancel.cancel()
   }
@@ -109,10 +124,7 @@ impl From<tokio::net::TcpStream> for TcpStream {
 fn create_js_runtime() -> JsRuntime {
   let mut runtime = JsRuntime::new(Default::default());
   runtime.register_op("listen", deno_core::op_sync(op_listen));
-  runtime.register_op("close", deno_core::op_sync(op_close));
   runtime.register_op("accept", deno_core::op_async(op_accept));
-  runtime.register_op("read", deno_core::op_async(op_read));
-  runtime.register_op("write", deno_core::op_async(op_write));
   runtime.sync_ops_cache();
   runtime
 }
@@ -131,15 +143,6 @@ fn op_listen(
   Ok(rid)
 }
 
-fn op_close(
-  state: &mut OpState,
-  rid: ResourceId,
-  _: (),
-) -> Result<(), AnyError> {
-  log::debug!("close rid={}", rid);
-  state.resource_table.close(rid).map(|_| ())
-}
-
 async fn op_accept(
   state: Rc<RefCell<OpState>>,
   rid: ResourceId,
@@ -153,30 +156,6 @@ async fn op_accept(
   Ok(rid)
 }
 
-async fn op_read(
-  state: Rc<RefCell<OpState>>,
-  rid: ResourceId,
-  mut buf: ZeroCopyBuf,
-) -> Result<usize, AnyError> {
-  log::debug!("read rid={}", rid);
-
-  let stream = state.borrow().resource_table.get::<TcpStream>(rid)?;
-  let nread = stream.read(&mut buf).await?;
-  Ok(nread)
-}
-
-async fn op_write(
-  state: Rc<RefCell<OpState>>,
-  rid: ResourceId,
-  buf: ZeroCopyBuf,
-) -> Result<usize, AnyError> {
-  log::debug!("write rid={}", rid);
-
-  let stream = state.borrow().resource_table.get::<TcpStream>(rid)?;
-  let nwritten = stream.write(&buf).await?;
-  Ok(nwritten)
-}
-
 fn main() {
   log::set_logger(&Logger).unwrap();
   log::set_max_level(