feat(runtime/worker): Structured cloning worker message passing (deno…

…land#9323)

This commit upgrade "Worker.postMessage()" implementation to use 
structured clone algorithm instead of non-spec compliant JSON serialization.

serde_v8/src/magic/buffer.rs

@@ -1,17 +1,17 @@
 use rusty_v8 as v8;
 
-use std::cell::Cell;
 use std::fmt;
 use std::ops::Deref;
 use std::ops::DerefMut;
+use std::sync::Mutex;
 
 use super::zero_copy_buf::ZeroCopyBuf;
 
 // An asymmetric wrapper around ZeroCopyBuf,
 // allowing us to use a single type for familiarity
 pub enum MagicBuffer {
  FromV8(ZeroCopyBuf),
- ToV8(Cell<Option<Box<[u8]>>>),
+ ToV8(Mutex<Option<Box<[u8]>>>),
 }
 
 impl MagicBuffer {
@@ -21,6 +21,10 @@ impl MagicBuffer {
  ) -> Self {
  Self::FromV8(ZeroCopyBuf::new(scope, view))
  }
+
+ pub fn empty() -> Self {
+ MagicBuffer::ToV8(Mutex::new(Some(vec![0_u8; 0].into_boxed_slice())))
+ }
 }
 
 impl Clone for MagicBuffer {
@@ -65,7 +69,7 @@ impl DerefMut for MagicBuffer {
 
 impl From<Box<[u8]>> for MagicBuffer {
  fn from(buf: Box<[u8]>) -> Self {
- MagicBuffer::ToV8(Cell::new(Some(buf)))
+ MagicBuffer::ToV8(Mutex::new(Some(buf)))
  }
 }
 
@@ -88,8 +92,11 @@ impl serde::Serialize for MagicBuffer {
 
  let mut s = serializer.serialize_struct(BUF_NAME, 1)?;
  let boxed: Box<[u8]> = match self {
- Self::FromV8(_) => unreachable!(),
- Self::ToV8(x) => x.take().expect("MagicBuffer was empty"),
+ Self::FromV8(buf) => {
+ let value: &[u8] = &buf;
+ value.into()
+ }
+ Self::ToV8(x) => x.lock().unwrap().take().expect("MagicBuffer was empty"),
  };
  let hack: [usize; 2] = unsafe { std::mem::transmute(boxed) };
  let f1: u64 = hack[0] as u64;