LibWeb+WebWorker: Use IPC mechanics for structured serialization

Our structured serialization implementation had its own bespoke encoder
and decoder to serialize JS values. It also used a u32 buffer under the
hood, which made using its structures a bit awkward. We had previously
worked around its data structures in transferable streams, which nested
transfers of MessagePort instances. We basically had to add hooks into
the MessagePort to route to the correct transfer receiving steps, and
we could not invoke the correct AOs directly as the spec dictates.

We now use IPC mechanics to encode and decode data. This works because,
although we are encoding JS values, we are only ultimately encoding
primitive and basic AK types. The resulting data structures actually
enforce that we implement transferable streams exactly as the spec is
worded (I had planned to do that in a separate commit, but the fallout
of this patch actually required that change).
This commit is contained in:
Timothy Flynn 2025-07-17 09:51:04 -04:00 committed by Tim Flynn
commit 64abc6101d
Notes: github-actions[bot] 2025-07-18 14:10:44 +00:00
44 changed files with 765 additions and 970 deletions

View file

@ -36,7 +36,7 @@ WorkerHost::WorkerHost(URL::URL url, Web::Bindings::WorkerType type, String name
WorkerHost::~WorkerHost() = default;
// https://html.spec.whatwg.org/multipage/workers.html#run-a-worker
void WorkerHost::run(GC::Ref<Web::Page> page, Web::HTML::TransferDataHolder message_port_data, Web::HTML::SerializedEnvironmentSettingsObject const& outside_settings_snapshot, Web::Bindings::RequestCredentials credentials, bool is_shared)
void WorkerHost::run(GC::Ref<Web::Page> page, Web::HTML::TransferDataEncoder message_port_data, Web::HTML::SerializedEnvironmentSettingsObject const& outside_settings_snapshot, Web::Bindings::RequestCredentials credentials, bool is_shared)
{
// 3. Let unsafeWorkerCreationTime be the unsafe shared current time.
auto unsafe_worker_creation_time = Web::HighResolutionTime::unsafe_shared_current_time();
@ -157,6 +157,7 @@ void WorkerHost::run(GC::Ref<Web::Page> page, Web::HTML::TransferDataHolder mess
auto on_complete_function = [inside_settings, worker_global_scope, message_port_data = move(message_port_data), url = m_url, is_shared](GC::Ptr<Web::HTML::Script> script) mutable {
auto& realm = inside_settings->realm();
// 1. If script is null or if script's error to rethrow is non-null, then:
if (!script || !script->error_to_rethrow().is_null()) {
// FIXME: 1. Queue a global task on the DOM manipulation task source given worker's relevant global object to fire an event named error at worker.
@ -180,7 +181,8 @@ void WorkerHost::run(GC::Ref<Web::Page> page, Web::HTML::TransferDataHolder mess
worker_global_scope->set_internal_port(inside_port);
// 5. Entangle outside port and inside port.
MUST(inside_port->transfer_receiving_steps(message_port_data));
Web::HTML::TransferDataDecoder decoder { move(message_port_data) };
MUST(inside_port->transfer_receiving_steps(decoder));
// 6. Create a new WorkerLocation object and associate it with worker global scope.
worker_global_scope->set_location(realm.create<Web::HTML::WorkerLocation>(*worker_global_scope));