Everywhere: Hoist the Libraries folder to the top-level

Author: https://github.com/trflynn89
Commit: 93712b24bf
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2256
Reviewed-by: https://github.com/sideshowbarker

Libraries/LibWeb/HTML/MessagePort.cpp

@@ -0,0 +1,449 @@
+/*
+ * Copyright (c) 2021, Andreas Kling <andreas@ladybird.org>
+ * Copyright (c) 2023, Andrew Kaster <akaster@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/ByteReader.h>
+#include <AK/MemoryStream.h>
+#include <LibCore/Socket.h>
+#include <LibCore/System.h>
+#include <LibIPC/Decoder.h>
+#include <LibIPC/Encoder.h>
+#include <LibIPC/File.h>
+#include <LibIPC/Transport.h>
+#include <LibWeb/Bindings/ExceptionOrUtils.h>
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/Bindings/MessagePortPrototype.h>
+#include <LibWeb/DOM/EventDispatcher.h>
+#include <LibWeb/HTML/EventNames.h>
+#include <LibWeb/HTML/MessageEvent.h>
+#include <LibWeb/HTML/MessagePort.h>
+#include <LibWeb/HTML/Scripting/TemporaryExecutionContext.h>
+#include <LibWeb/HTML/StructuredSerializeOptions.h>
+#include <LibWeb/HTML/WorkerGlobalScope.h>
+
+namespace Web::HTML {
+
+constexpr u8 IPC_FILE_TAG = 0xA5;
+
+JS_DEFINE_ALLOCATOR(MessagePort);
+
+static HashTable<JS::RawGCPtr<MessagePort>>& all_message_ports()
+{
+    static HashTable<JS::RawGCPtr<MessagePort>> ports;
+    return ports;
+}
+
+JS::NonnullGCPtr<MessagePort> MessagePort::create(JS::Realm& realm)
+{
+    return realm.heap().allocate<MessagePort>(realm, realm);
+}
+
+MessagePort::MessagePort(JS::Realm& realm)
+    : DOM::EventTarget(realm)
+{
+    all_message_ports().set(this);
+}
+
+MessagePort::~MessagePort()
+{
+    all_message_ports().remove(this);
+    disentangle();
+}
+
+void MessagePort::for_each_message_port(Function<void(MessagePort&)> callback)
+{
+    for (auto port : all_message_ports())
+        callback(*port);
+}
+
+void MessagePort::initialize(JS::Realm& realm)
+{
+    Base::initialize(realm);
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(MessagePort);
+}
+
+void MessagePort::visit_edges(Cell::Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    visitor.visit(m_remote_port);
+    visitor.visit(m_worker_event_target);
+}
+
+bool MessagePort::is_entangled() const
+{
+    return m_transport.has_value();
+}
+
+void MessagePort::set_worker_event_target(JS::NonnullGCPtr<DOM::EventTarget> target)
+{
+    m_worker_event_target = target;
+}
+
+// https://html.spec.whatwg.org/multipage/web-messaging.html#message-ports:transfer-steps
+WebIDL::ExceptionOr<void> MessagePort::transfer_steps(HTML::TransferDataHolder& data_holder)
+{
+    // 1. Set value's has been shipped flag to true.
+    m_has_been_shipped = true;
+
+    // FIXME: 2. Set dataHolder.[[PortMessageQueue]] to value's port message queue.
+    // FIXME: Support delivery of messages that haven't been delivered yet on the other side
+
+    // 3. If value is entangled with another port remotePort, then:
+    if (is_entangled()) {
+        // 1. Set remotePort's has been shipped flag to true.
+        m_remote_port->m_has_been_shipped = true;
+
+        // 2. Set dataHolder.[[RemotePort]] to remotePort.
+        if constexpr (IsSame<IPC::Transport, IPC::TransportSocket>) {
+            auto fd = MUST(m_transport->release_underlying_transport_for_transfer());
+            m_transport = {};
+            data_holder.fds.append(IPC::File::adopt_fd(fd));
+            data_holder.data.append(IPC_FILE_TAG);
+        } else {
+            VERIFY(false && "Don't know how to transfer IPC::Transport type");
+        }
+    }
+
+    // 4. Otherwise, set dataHolder.[[RemotePort]] to null.
+    else {
+        data_holder.data.append(0);
+    }
+
+    return {};
+}
+
+WebIDL::ExceptionOr<void> MessagePort::transfer_receiving_steps(HTML::TransferDataHolder& data_holder)
+{
+    // 1. Set value's has been shipped flag to true.
+    m_has_been_shipped = true;
+
+    // FIXME 2. Move all the tasks that are to fire message events in dataHolder.[[PortMessageQueue]] to the port message queue of value,
+    //     if any, leaving value's port message queue in its initial disabled state, and, if value's relevant global object is a Window,
+    //     associating the moved tasks with value's relevant global object's associated Document.
+
+    // 3. If dataHolder.[[RemotePort]] is not null, then entangle dataHolder.[[RemotePort]] and value.
+    //     (This will disentangle dataHolder.[[RemotePort]] from the original port that was transferred.)
+    auto fd_tag = data_holder.data.take_first();
+    if (fd_tag == IPC_FILE_TAG) {
+        if constexpr (IsSame<IPC::Transport, IPC::TransportSocket>) {
+            auto fd = data_holder.fds.take_first();
+            m_transport = IPC::Transport(MUST(Core::LocalSocket::adopt_fd(fd.take_fd())));
+
+            m_transport->set_up_read_hook([strong_this = JS::make_handle(this)]() {
+                strong_this->read_from_transport();
+            });
+        } else {
+            VERIFY(false && "Don't know how to receive IPC::Transport type");
+        }
+    } else if (fd_tag != 0) {
+        dbgln("Unexpected byte {:x} in MessagePort transfer data", fd_tag);
+        VERIFY_NOT_REACHED();
+    }
+
+    return {};
+}
+
+void MessagePort::disentangle()
+{
+    if (m_remote_port)
+        m_remote_port->m_remote_port = nullptr;
+    m_remote_port = nullptr;
+
+    m_transport = {};
+
+    m_worker_event_target = nullptr;
+}
+
+// https://html.spec.whatwg.org/multipage/web-messaging.html#entangle
+void MessagePort::entangle_with(MessagePort& remote_port)
+{
+    if (m_remote_port.ptr() == &remote_port)
+        return;
+
+    // 1. If one of the ports is already entangled, then disentangle it and the port that it was entangled with.
+    if (is_entangled())
+        disentangle();
+    if (remote_port.is_entangled())
+        remote_port.disentangle();
+
+    // 2. Associate the two ports to be entangled, so that they form the two parts of a new channel.
+    //    (There is no MessageChannel object that represents this channel.)
+    remote_port.m_remote_port = this;
+    m_remote_port = &remote_port;
+
+    // FIXME: Abstract such that we can entangle different transport types
+    auto create_paired_sockets = []() -> Array<NonnullOwnPtr<Core::LocalSocket>, 2> {
+        int fds[2] = {};
+        MUST(Core::System::socketpair(AF_LOCAL, SOCK_STREAM, 0, fds));
+        auto socket0 = MUST(Core::LocalSocket::adopt_fd(fds[0]));
+        MUST(socket0->set_blocking(false));
+        MUST(socket0->set_close_on_exec(true));
+        auto socket1 = MUST(Core::LocalSocket::adopt_fd(fds[1]));
+        MUST(socket1->set_blocking(false));
+        MUST(socket1->set_close_on_exec(true));
+
+        return Array { move(socket0), move(socket1) };
+    };
+
+    auto sockets = create_paired_sockets();
+    m_transport = IPC::Transport(move(sockets[0]));
+    m_remote_port->m_transport = IPC::Transport(move(sockets[1]));
+
+    m_transport->set_up_read_hook([strong_this = JS::make_handle(this)]() {
+        strong_this->read_from_transport();
+    });
+
+    m_remote_port->m_transport->set_up_read_hook([remote_port = JS::make_handle(m_remote_port)]() {
+        remote_port->read_from_transport();
+    });
+}
+
+// https://html.spec.whatwg.org/multipage/web-messaging.html#dom-messageport-postmessage-options
+WebIDL::ExceptionOr<void> MessagePort::post_message(JS::Value message, Vector<JS::Handle<JS::Object>> const& transfer)
+{
+    // 1. Let targetPort be the port with which this MessagePort is entangled, if any; otherwise let it be null.
+    JS::GCPtr<MessagePort> target_port = m_remote_port;
+
+    // 2. Let options be «[ "transfer" → transfer ]».
+    auto options = StructuredSerializeOptions { transfer };
+
+    // 3. Run the message port post message steps providing this, targetPort, message and options.
+    return message_port_post_message_steps(target_port, message, options);
+}
+
+// https://html.spec.whatwg.org/multipage/web-messaging.html#dom-messageport-postmessage
+WebIDL::ExceptionOr<void> MessagePort::post_message(JS::Value message, StructuredSerializeOptions const& options)
+{
+    // 1. Let targetPort be the port with which this MessagePort is entangled, if any; otherwise let it be null.
+    JS::GCPtr<MessagePort> target_port = m_remote_port;
+
+    // 2. Run the message port post message steps providing targetPort, message and options.
+    return message_port_post_message_steps(target_port, message, options);
+}
+
+// https://html.spec.whatwg.org/multipage/web-messaging.html#message-port-post-message-steps
+WebIDL::ExceptionOr<void> MessagePort::message_port_post_message_steps(JS::GCPtr<MessagePort> target_port, JS::Value message, StructuredSerializeOptions const& options)
+{
+    auto& realm = this->realm();
+    auto& vm = this->vm();
+
+    // 1. Let transfer be options["transfer"].
+    auto const& transfer = options.transfer;
+
+    // 2. If transfer contains this MessagePort, then throw a "DataCloneError" DOMException.
+    for (auto const& handle : transfer) {
+        if (handle == this)
+            return WebIDL::DataCloneError::create(realm, "Cannot transfer a MessagePort to itself"_string);
+    }
+
+    // 3. Let doomed be false.
+    bool doomed = false;
+
+    // 4. If targetPort is not null and transfer contains targetPort, then set doomed to true and optionally report to a developer console that the target port was posted to itself, causing the communication channel to be lost.
+    if (target_port) {
+        for (auto const& handle : transfer) {
+            if (handle == target_port.ptr()) {
+                doomed = true;
+                dbgln("FIXME: Report to a developer console that the target port was posted to itself, causing the communication channel to be lost");
+            }
+        }
+    }
+
+    // 5. Let serializeWithTransferResult be StructuredSerializeWithTransfer(message, transfer). Rethrow any exceptions.
+    auto serialize_with_transfer_result = TRY(structured_serialize_with_transfer(vm, message, transfer));
+
+    // 6. If targetPort is null, or if doomed is true, then return.
+    // IMPLEMENTATION DEFINED: Actually check the socket here, not the target port.
+    //     If there's no target message port in the same realm, we still want to send the message over IPC
+    if (!m_transport.has_value() || doomed) {
+        return {};
+    }
+
+    // 7. Add a task that runs the following steps to the port message queue of targetPort:
+    post_port_message(move(serialize_with_transfer_result));
+
+    return {};
+}
+
+ErrorOr<void> MessagePort::send_message_on_transport(SerializedTransferRecord const& serialize_with_transfer_result)
+{
+    IPC::MessageBuffer buffer;
+    IPC::Encoder encoder(buffer);
+    MUST(encoder.encode(serialize_with_transfer_result));
+
+    TRY(buffer.transfer_message(*m_transport));
+    return {};
+}
+
+void MessagePort::post_port_message(SerializedTransferRecord serialize_with_transfer_result)
+{
+    if (!m_transport.has_value() || !m_transport->is_open())
+        return;
+    if (auto result = send_message_on_transport(serialize_with_transfer_result); result.is_error()) {
+        dbgln("Failed to post message: {}", result.error());
+        disentangle();
+    }
+}
+
+ErrorOr<MessagePort::ParseDecision> MessagePort::parse_message()
+{
+    static constexpr size_t HEADER_SIZE = sizeof(u32);
+
+    auto num_bytes_ready = m_buffered_data.size();
+    switch (m_socket_state) {
+    case SocketState::Header: {
+        if (num_bytes_ready < HEADER_SIZE)
+            return ParseDecision::NotEnoughData;
+
+        m_socket_incoming_message_size = ByteReader::load32(m_buffered_data.data());
+        // NOTE: We don't decrement the number of ready bytes because we want to remove the entire
+        //       message + header from the buffer in one go on success
+        m_socket_state = SocketState::Data;
+        [[fallthrough]];
+    }
+    case SocketState::Data: {
+        if (num_bytes_ready < HEADER_SIZE + m_socket_incoming_message_size)
+            return ParseDecision::NotEnoughData;
+
+        auto payload = m_buffered_data.span().slice(HEADER_SIZE, m_socket_incoming_message_size);
+
+        FixedMemoryStream stream { payload, FixedMemoryStream::Mode::ReadOnly };
+        IPC::Decoder decoder { stream, m_unprocessed_fds };
+
+        auto serialized_transfer_record = TRY(decoder.decode<SerializedTransferRecord>());
+
+        // Make sure to advance our state machine before dispatching the MessageEvent,
+        // as dispatching events can run arbitrary JS (and cause us to receive another message!)
+        m_socket_state = SocketState::Header;
+
+        m_buffered_data.remove(0, HEADER_SIZE + m_socket_incoming_message_size);
+
+        // Note: this is step 7 of message_port_post_message_steps:
+        // 7. Add a task that runs the following steps to the port message queue of targetPort:
+        queue_global_task(Task::Source::PostedMessage, relevant_global_object(*this), JS::create_heap_function(heap(), [this, serialized_transfer_record = move(serialized_transfer_record)]() mutable {
+            this->post_message_task_steps(serialized_transfer_record);
+        }));
+
+        break;
+    }
+    case SocketState::Error:
+        return Error::from_errno(ENOMSG);
+    }
+
+    return ParseDecision::ParseNextMessage;
+}
+
+void MessagePort::read_from_transport()
+{
+    auto&& [bytes, fds] = m_transport->read_as_much_as_possible_without_blocking([this] {
+        queue_global_task(Task::Source::PostedMessage, relevant_global_object(*this), JS::create_heap_function(heap(), [this] {
+            this->close();
+        }));
+    });
+
+    m_buffered_data.append(bytes.data(), bytes.size());
+
+    for (auto fd : fds)
+        m_unprocessed_fds.enqueue(IPC::File::adopt_fd(fd));
+
+    while (true) {
+        auto parse_decision_or_error = parse_message();
+        if (parse_decision_or_error.is_error()) {
+            dbgln("MessagePort::read_from_socket(): Failed to parse message: {}", parse_decision_or_error.error());
+            return;
+        }
+        if (parse_decision_or_error.value() == ParseDecision::NotEnoughData)
+            break;
+    }
+}
+
+void MessagePort::post_message_task_steps(SerializedTransferRecord& serialize_with_transfer_result)
+{
+    // 1. Let finalTargetPort be the MessagePort in whose port message queue the task now finds itself.
+    // NOTE: This can be different from targetPort, if targetPort itself was transferred and thus all its tasks moved along with it.
+    auto* final_target_port = this;
+
+    // IMPLEMENTATION DEFINED:
+    // https://html.spec.whatwg.org/multipage/workers.html#dedicated-workers-and-the-worker-interface
+    //      Worker objects act as if they had an implicit MessagePort associated with them.
+    //      All messages received by that port must immediately be retargeted at the Worker object.
+    // We therefore set a special event target for those implicit ports on the Worker and the WorkerGlobalScope objects
+    EventTarget* message_event_target = final_target_port;
+    if (m_worker_event_target != nullptr) {
+        message_event_target = m_worker_event_target;
+    }
+
+    // 2. Let targetRealm be finalTargetPort's relevant realm.
+    auto& target_realm = relevant_realm(*final_target_port);
+    auto& target_vm = target_realm.vm();
+
+    // 3. Let deserializeRecord be StructuredDeserializeWithTransfer(serializeWithTransferResult, targetRealm).
+    TemporaryExecutionContext context { relevant_realm(*final_target_port) };
+    auto deserialize_record_or_error = structured_deserialize_with_transfer(target_vm, serialize_with_transfer_result);
+    if (deserialize_record_or_error.is_error()) {
+        // If this throws an exception, catch it, fire an event named messageerror at finalTargetPort, using MessageEvent, and then return.
+        auto exception = deserialize_record_or_error.release_error();
+        MessageEventInit event_init {};
+        message_event_target->dispatch_event(MessageEvent::create(target_realm, HTML::EventNames::messageerror, event_init));
+        return;
+    }
+    auto deserialize_record = deserialize_record_or_error.release_value();
+
+    // 4. Let messageClone be deserializeRecord.[[Deserialized]].
+    auto message_clone = deserialize_record.deserialized;
+
+    // 5. Let newPorts be a new frozen array consisting of all MessagePort objects in deserializeRecord.[[TransferredValues]], if any, maintaining their relative order.
+    // FIXME: Use a FrozenArray
+    Vector<JS::Handle<MessagePort>> new_ports;
+    for (auto const& object : deserialize_record.transferred_values) {
+        if (is<HTML::MessagePort>(*object)) {
+            new_ports.append(verify_cast<MessagePort>(*object));
+        }
+    }
+
+    // 6. Fire an event named message at finalTargetPort, using MessageEvent, with the data attribute initialized to messageClone and the ports attribute initialized to newPorts.
+    MessageEventInit event_init {};
+    event_init.data = message_clone;
+    event_init.ports = move(new_ports);
+    message_event_target->dispatch_event(MessageEvent::create(target_realm, HTML::EventNames::message, event_init));
+}
+
+// https://html.spec.whatwg.org/multipage/web-messaging.html#dom-messageport-start
+void MessagePort::start()
+{
+    if (!is_entangled())
+        return;
+
+    VERIFY(m_transport.has_value());
+
+    // TODO: The start() method steps are to enable this's port message queue, if it is not already enabled.
+}
+
+// https://html.spec.whatwg.org/multipage/web-messaging.html#dom-messageport-close
+void MessagePort::close()
+{
+    // 1. Set this MessagePort object's [[Detached]] internal slot value to true.
+    set_detached(true);
+
+    // 2. If this MessagePort object is entangled, disentangle it.
+    if (is_entangled())
+        disentangle();
+}
+
+#undef __ENUMERATE
+#define __ENUMERATE(attribute_name, event_name)                         \
+    void MessagePort::set_##attribute_name(WebIDL::CallbackType* value) \
+    {                                                                   \
+        set_event_handler_attribute(event_name, value);                 \
+    }                                                                   \
+    WebIDL::CallbackType* MessagePort::attribute_name()                 \
+    {                                                                   \
+        return event_handler_attribute(event_name);                     \
+    }
+ENUMERATE_MESSAGE_PORT_EVENT_HANDLERS(__ENUMERATE)
+#undef __ENUMERATE
+
+}