The HTML structured serialize algorithm treats transferable and
serializable as two different bits. A web platform interface can be
both transferable and serializable.
Splits BaseObject::TransferMode to be able to compose the two bits
and distinguishes the transferable and cloneable.
PR-URL: https://github.com/nodejs/node/pull/47956
Refs: cf13b9b465
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Daeyeon Jeong <daeyeon.dev@gmail.com>
Co-authored-by: James M Snell <jasnell@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/44048
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>
Reviewed-By: Paolo Insogna <paolo@cowtech.it>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Adds a new `makeTransferable()` utility that can construct a
`JSTransferable` object that does not directly extend the
`JSTransferable` JavaScript class.
Because JavaScript does not support multiple inheritance, it is
not possible (without help) to implement a class that extends
both `JSTransferable` and, for instance, `EventTarget` without
incurring a significant additional complexity and performance
cost by making all `EventTarget` instances extend `JSTransferable`...
That is, we *don't* want:
```js
class EventTarget extends JSTransferable { ... }
```
The `makeTransferable()` allows us to create objects that are
backed internally by `JSTransferable` without having to actually
extend it by leveraging the magic of `Reflect.construct()`.
```js
const {
JSTransferable,
kClone,
kDeserialize,
kConstructor,
makeTransferable,
} = require('internal/worker/js_transferable');
class E {
constructor(b) {
this.b = b;
}
}
class F extends E {
[kClone]() { /** ... **/ }
[kDeserialize]() { /** ... **/ }
static [kConstructor]() { return makeTransferable(F); }
}
const f = makeTransferable(F, 1);
f instanceof F; // true
f instanceof E; // true
f instanceof JSTransferable; // false
const mc = new MessageChannel();
mc.port1.onmessage = ({ data }) => {
data instanceof F; // true
data instanceof E; // true
data instanceof JSTransferable; // false
};
mc.port2.postMessage(f); // works!
```
The additional `internal/test/transfer.js` file is required for the
test because successfully deserializing transferable classes requires
that they be located in `lib/internal` for now.
Signed-off-by: James M Snell <jasnell@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/38383
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Khaidi Chu <i@2333.moe>
Allow passing `FileHandle` instances in the transfer list
of a `.postMessage()` call.
PR-URL: https://github.com/nodejs/node/pull/33772
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Enable JS wrapper objects to be used as transferable or cloneable
objects in `postMessage()` calls, by having them extend a C++-backed
class.
This requires a few internal changes:
- This commit adds the possibility for transferred objects to
read/write JS values at the end of the serialization/deserialization
phases.
- This commit adds the possibility for transferred objects to list
sub-transferables, e.g. typically the public JS wrapper class
would list its C++ handle in there.
- This commit adds usage of `BaseObject` in a few more places, because
now during deserialization weakly held objects can also be involved,
in addition to `MessagePort`s.
PR-URL: https://github.com/nodejs/node/pull/33772
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
