Welcome to better optimised op calls! Currently opSync is called with parameters of every type and count. This most definitely makes the call megamorphic. Additionally, it seems that spread params leads to V8 not being able to optimise the calls quite as well (apparently Fast Calls cannot be used with spread params).
Monomorphising op calls should lead to some improved performance. Now that unwrapping of sync ops results is done on Rust side, this is pretty simple:
```
opSync("op_foo", param1, param2);
// -> turns to
ops.op_foo(param1, param2);
```
This means sync op calls are now just directly calling the native binding function. When V8 Fast API Calls are enabled, this will enable those to be called on the optimised path.
Monomorphising async ops likely requires using callbacks and is left as an exercise to the reader.
This commit adds `readable` and `writable` properties to `Deno.File` and
`Deno.Conn`. This makes it very simple to use files and network sockets
with fetch or the native HTTP server.
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
Currently all async ops are polled lazily, which means that op
initialization code is postponed until control is yielded to the event
loop. This has some weird consequences, e.g.
```js
let listener = Deno.listen(...);
let conn_promise = listener.accept();
listener.close();
// `BadResource` is thrown. A reasonable error would be `Interrupted`.
let conn = await conn_promise;
```
JavaScript promises are expected to be eagerly evaluated. This patch
makes ops actually do that.
