/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
//! The script task is the task that owns the DOM in memory, runs JavaScript, and spawns parsing
//! and layout tasks. It's in charge of processing events for all same-origin pages in a frame
//! tree, and manages the entire lifetime of pages in the frame tree from initial request to
//! teardown.
//!
//! Page loads follow a two-step process. When a request for a new page load is received, the
//! network request is initiated and the relevant data pertaining to the new page is stashed.
//! While the non-blocking request is ongoing, the script task is free to process further events,
//! noting when they pertain to ongoing loads (such as resizes/viewport adjustments). When the
//! initial response is received for an ongoing load, the second phase starts - the frame tree
//! entry is created, along with the Window and Document objects, and the appropriate parser
//! takes over the response body. Once parsing is complete, the document lifecycle for loading
//! a page runs its course and the script task returns to processing events in the main event
//! loop.
#![allow(unsafe_code)]
use dom::bindings::cell::DOMRefCell;
use dom::bindings::codegen::Bindings::DocumentBinding::{DocumentMethods, DocumentReadyState};
use dom::bindings::codegen::InheritTypes::{ElementCast, EventTargetCast, HTMLIFrameElementCast, NodeCast, EventCast};
use dom::bindings::conversions::FromJSValConvertible;
use dom::bindings::conversions::StringificationBehavior;
use dom::bindings::js::{JS, JSRef, Temporary, OptionalRootable, RootedReference};
use dom::bindings::js::{RootCollection, RootCollectionPtr, Unrooted};
use dom::bindings::refcounted::{LiveDOMReferences, Trusted, TrustedReference};
use dom::bindings::structuredclone::StructuredCloneData;
use dom::bindings::trace::{JSTraceable, trace_collections};
use dom::bindings::utils::{wrap_for_same_compartment, pre_wrap};
use dom::document::{Document, IsHTMLDocument, DocumentHelpers, DocumentProgressHandler, DocumentProgressTask, DocumentSource};
use dom::element::{Element, AttributeHandlers};
use dom::event::{Event, EventHelpers, EventBubbles, EventCancelable};
use dom::htmliframeelement::HTMLIFrameElementHelpers;
use dom::uievent::UIEvent;
use dom::eventtarget::EventTarget;
use dom::node::{self, Node, NodeHelpers, NodeDamage, window_from_node};
use dom::window::{Window, WindowHelpers, ScriptHelpers, ReflowReason};
use parse::html::{HTMLInput, parse_html};
use layout_interface::{ScriptLayoutChan, LayoutChan, ReflowGoal, ReflowQueryType};
use layout_interface;
use page::{Page, IterablePage, Frame};
use timers::TimerId;
use devtools;
use devtools_traits::{DevtoolsControlChan, DevtoolsControlPort, DevtoolsPageInfo};
use devtools_traits::{DevtoolsControlMsg, DevtoolScriptControlMsg};
use script_traits::CompositorEvent;
use script_traits::CompositorEvent::{ResizeEvent, ReflowEvent, ClickEvent};
use script_traits::CompositorEvent::{MouseDownEvent, MouseUpEvent};
use script_traits::CompositorEvent::{MouseMoveEvent, KeyEvent};
use script_traits::{NewLayoutInfo, OpaqueScriptLayoutChannel};
use script_traits::{ConstellationControlMsg, ScriptControlChan};
use script_traits::ScriptTaskFactory;
use msg::compositor_msg::ReadyState::{FinishedLoading, Loading, PerformingLayout};
use msg::compositor_msg::{LayerId, ScriptListener};
use msg::constellation_msg::{ConstellationChan};
use msg::constellation_msg::{LoadData, PipelineId, SubpageId, MozBrowserEvent, WorkerId};
use msg::constellation_msg::{Failure, WindowSizeData, PipelineExitType};
use msg::constellation_msg::Msg as ConstellationMsg;
use net_traits::{ResourceTask, ControlMsg, LoadResponse};
use net_traits::LoadData as NetLoadData;
use net_traits::image_cache_task::ImageCacheTask;
use net_traits::storage_task::StorageTask;
use string_cache::Atom;
use util::geometry::to_frac_px;
use util::smallvec::SmallVec;
use util::str::DOMString;
use util::task::{spawn_named, spawn_named_with_send_on_failure};
use util::task_state;
use geom::Rect;
use geom::point::Point2D;
use hyper::header::{LastModified, Headers};
use js::jsapi::{JS_SetWrapObjectCallbacks, JS_SetGCZeal, JS_SetExtraGCRootsTracer, JS_DEFAULT_ZEAL_FREQ};
use js::jsapi::{JSContext, JSRuntime, JSObject, JSTracer};
use js::jsapi::{JS_SetGCParameter, JSGC_MAX_BYTES};
use js::jsapi::{JS_SetGCCallback, JSGCStatus, JSGC_BEGIN, JSGC_END};
use js::rust::{Cx, RtUtils};
use js;
use url::Url;
use libc;
use std::ascii::AsciiExt;
use std::any::Any;
use std::borrow::ToOwned;
use std::cell::{Cell, RefCell};
use std::num::ToPrimitive;
use std::option::Option;
use std::ptr;
use std::rc::Rc;
use std::result::Result;
use std::sync::mpsc::{channel, Sender, Receiver, Select};
use std::u32;
use time::Tm;
thread_local!(pub static STACK_ROOTS: Cell<Option<RootCollectionPtr>> = Cell::new(None));
thread_local!(static SCRIPT_TASK_ROOT: RefCell<Option<*const ScriptTask>> = RefCell::new(None));
unsafe extern fn trace_script_tasks(tr: *mut JSTracer, _data: *mut libc::c_void) {
SCRIPT_TASK_ROOT.with(|root| {
if let Some(script_task) = *root.borrow() {
(*script_task).trace(tr);
}
});
}
/// A document load that is in the process of fetching the requested resource. Contains
/// data that will need to be present when the document and frame tree entry are created,
/// but is only easily available at initiation of the load and on a push basis (so some
/// data will be updated according to future resize events, viewport changes, etc.)
#[jstraceable]
struct InProgressLoad {
/// The pipeline which requested this load.
pipeline_id: PipelineId,
/// The parent pipeline and child subpage associated with this load, if any.
parent_info: Option<(PipelineId, SubpageId)>,
/// The current window size associated with this pipeline.
window_size: Option<WindowSizeData>,
/// Channel to the layout task associated with this pipeline.
layout_chan: LayoutChan,
/// The current viewport clipping rectangle applying to this pipelie, if any.
clip_rect: Option<Rect<f32>>,
/// The requested URL of the load.
url: Url,
}
impl InProgressLoad {
/// Create a new InProgressLoad object.
fn new(id: PipelineId,
parent_info: Option<(PipelineId, SubpageId)>,
layout_chan: LayoutChan,
window_size: Option<WindowSizeData>,
url: Url) -> InProgressLoad {
InProgressLoad {
pipeline_id: id,
parent_info: parent_info,
layout_chan: layout_chan,
window_size: window_size,
clip_rect: None,
url: url,
}
}
}
#[derive(Copy)]
pub enum TimerSource {
FromWindow(PipelineId),
FromWorker
}
pub trait Runnable {
fn handler(self: Box<Self>);
}
pub trait MainThreadRunnable {
fn handler(self: Box<Self>, script_task: &ScriptTask);
}
/// Messages used to control script event loops, such as ScriptTask and
/// DedicatedWorkerGlobalScope.
pub enum ScriptMsg {
/// Acts on a fragment URL load on the specified pipeline (only dispatched
/// to ScriptTask).
TriggerFragment(PipelineId, String),
/// Begins a content-initiated load on the specified pipeline (only
/// dispatched to ScriptTask).
Navigate(PipelineId, LoadData),
/// Fires a JavaScript timeout
/// TimerSource must be FromWindow when dispatched to ScriptTask and
/// must be FromWorker when dispatched to a DedicatedGlobalWorkerScope
FireTimer(TimerSource, TimerId),
/// Notifies the script that a window associated with a particular pipeline
/// should be closed (only dispatched to ScriptTask).
ExitWindow(PipelineId),
/// Message sent through Worker.postMessage (only dispatched to
/// DedicatedWorkerGlobalScope).
DOMMessage(StructuredCloneData),
/// Generic message that encapsulates event handling.
RunnableMsg(Box<Runnable+Send>),
/// Generic message for running tasks in the ScriptTask
MainThreadRunnableMsg(Box<MainThreadRunnable+Send>),
/// A DOM object's last pinned reference was removed (dispatched to all tasks).
RefcountCleanup(TrustedReference),
/// The final network response for a page has arrived.
PageFetchComplete(PipelineId, Option<SubpageId>, LoadResponse),
}
/// A cloneable interface for communicating with an event loop.
pub trait ScriptChan {
/// Send a message to the associated event loop.
fn send(&self, msg: ScriptMsg) -> Result<(), ()>;
/// Clone this handle.
fn clone(&self) -> Box<ScriptChan+Send>;
}
/// Encapsulates internal communication within the script task.
#[jstraceable]
pub struct NonWorkerScriptChan(pub Sender<ScriptMsg>);
impl ScriptChan for NonWorkerScriptChan {
fn send(&self, msg: ScriptMsg) -> Result<(), ()> {
let NonWorkerScriptChan(ref chan) = *self;
return chan.send(msg).map_err(|_| ());
}
fn clone(&self) -> Box<ScriptChan+Send> {
let NonWorkerScriptChan(ref chan) = *self;
box NonWorkerScriptChan((*chan).clone())
}
}
impl NonWorkerScriptChan {
/// Creates a new script chan.
pub fn new() -> (Receiver<ScriptMsg>, Box<NonWorkerScriptChan>) {
let (chan, port) = channel();
(port, box NonWorkerScriptChan(chan))
}
}
pub struct StackRootTLS;
impl StackRootTLS {
pub fn new(roots: &RootCollection) -> StackRootTLS {
STACK_ROOTS.with(|ref r| {
r.set(Some(RootCollectionPtr(roots as *const _)))
});
StackRootTLS
}
}
impl Drop for StackRootTLS {
fn drop(&mut self) {
STACK_ROOTS.with(|ref r| r.set(None));
}
}
/// Information for an entire page. Pages are top-level browsing contexts and can contain multiple
/// frames.
///
/// FIXME: Rename to `Page`, following WebKit?
#[jstraceable]
pub struct ScriptTask {
/// A handle to the information pertaining to page layout
page: DOMRefCell<Option<Rc<Page>>>,
/// A list of data pertaining to loads that have not yet received a network response
incomplete_loads: DOMRefCell<Vec<InProgressLoad>>,
/// A handle to the image cache task.
image_cache_task: ImageCacheTask,
/// A handle to the resource task.
resource_task: ResourceTask,
/// A handle to the storage task.
storage_task: StorageTask,
/// The port on which the script task receives messages (load URL, exit, etc.)
port: Receiver<ScriptMsg>,
/// A channel to hand out to script task-based entities that need to be able to enqueue
/// events in the event queue.
chan: NonWorkerScriptChan,
/// A channel to hand out to tasks that need to respond to a message from the script task.
control_chan: ScriptControlChan,
/// The port on which the constellation and layout tasks can communicate with the
/// script task.
control_port: Receiver<ConstellationControlMsg>,
/// For communicating load url messages to the constellation
constellation_chan: ConstellationChan,
/// A handle to the compositor for communicating ready state messages.
compositor: DOMRefCell<Box<ScriptListener+'static>>,
/// For providing instructions to an optional devtools server.
devtools_chan: Option<DevtoolsControlChan>,
/// For receiving commands from an optional devtools server. Will be ignored if
/// no such server exists.
devtools_port: DevtoolsControlPort,
devtools_sender: Sender<DevtoolScriptControlMsg>,
/// The JavaScript runtime.
js_runtime: js::rust::rt,
/// The JSContext.
js_context: DOMRefCell<Option<Rc<Cx>>>,
mouse_over_targets: DOMRefCell<Vec<JS<Node>>>
}
/// In the event of task failure, all data on the stack runs its destructor. However, there
/// are no reachable, owning pointers to the DOM memory, so it never gets freed by default
/// when the script task fails. The ScriptMemoryFailsafe uses the destructor bomb pattern
/// to forcibly tear down the JS compartments for pages associated with the failing ScriptTask.
struct ScriptMemoryFailsafe<'a> {
owner: Option<&'a ScriptTask>,
}
impl<'a> ScriptMemoryFailsafe<'a> {
fn neuter(&mut self) {
self.owner = None;
}
fn new(owner: &'a ScriptTask) -> ScriptMemoryFailsafe<'a> {
ScriptMemoryFailsafe {
owner: Some(owner),
}
}
}
#[unsafe_destructor]
impl<'a> Drop for ScriptMemoryFailsafe<'a> {
#[allow(unrooted_must_root)]
fn drop(&mut self) {
match self.owner {
Some(owner) => {
unsafe {
let page = owner.page.borrow_for_script_deallocation();
for page in page.iter() {
let window = Unrooted::from_temporary(page.window());
(*window.unsafe_get()).clear_js_context_for_script_deallocation();
}
*owner.js_context.borrow_for_script_deallocation() = None;
}
}
None => (),
}
}
}
impl ScriptTaskFactory for ScriptTask {
fn create_layout_channel(_phantom: Option<&mut ScriptTask>) -> OpaqueScriptLayoutChannel {
let (chan, port) = channel();
ScriptLayoutChan::new(chan, port)
}
fn clone_layout_channel(_phantom: Option<&mut ScriptTask>, pair: &OpaqueScriptLayoutChannel) -> Box<Any+Send> {
box pair.sender() as Box<Any+Send>
}
fn create<C>(_phantom: Option<&mut ScriptTask>,
id: PipelineId,
parent_info: Option<(PipelineId, SubpageId)>,
compositor: C,
layout_chan: &OpaqueScriptLayoutChannel,
control_chan: ScriptControlChan,
control_port: Receiver<ConstellationControlMsg>,
constellation_chan: ConstellationChan,
failure_msg: Failure,
resource_task: ResourceTask,
storage_task: StorageTask,
image_cache_task: ImageCacheTask,
devtools_chan: Option<DevtoolsControlChan>,
window_size: Option<WindowSizeData>,
load_data: LoadData)
where C: ScriptListener + Send + 'static {
let ConstellationChan(const_chan) = constellation_chan.clone();
let (script_chan, script_port) = channel();
let layout_chan = LayoutChan(layout_chan.sender());
spawn_named_with_send_on_failure("ScriptTask", task_state::SCRIPT, move || {
let script_task = ScriptTask::new(box compositor as Box<ScriptListener>,
script_port,
NonWorkerScriptChan(script_chan),
control_chan,
control_port,
constellation_chan,
resource_task,
storage_task,
image_cache_task,
devtools_chan);
SCRIPT_TASK_ROOT.with(|root| {
*root.borrow_mut() = Some(&script_task as *const _);
});
let mut failsafe = ScriptMemoryFailsafe::new(&script_task);
let new_load = InProgressLoad::new(id, parent_info, layout_chan, window_size,
load_data.url.clone());
script_task.start_page_load(new_load, load_data);
script_task.start();
// This must always be the very last operation performed before the task completes
failsafe.neuter();
}, ConstellationMsg::Failure(failure_msg), const_chan);
}
}
unsafe extern "C" fn debug_gc_callback(_rt: *mut JSRuntime, status: JSGCStatus) {
match status {
JSGC_BEGIN => task_state::enter(task_state::IN_GC),
JSGC_END => task_state::exit(task_state::IN_GC),
_ => (),
}
}
impl ScriptTask {
/// Creates a new script task.
pub fn new(compositor: Box<ScriptListener+'static>,
port: Receiver<ScriptMsg>,
chan: NonWorkerScriptChan,
control_chan: ScriptControlChan,
control_port: Receiver<ConstellationControlMsg>,
constellation_chan: ConstellationChan,
resource_task: ResourceTask,
storage_task: StorageTask,
img_cache_task: ImageCacheTask,
devtools_chan: Option<DevtoolsControlChan>)
-> ScriptTask {
let (js_runtime, js_context) = ScriptTask::new_rt_and_cx();
let wrap_for_same_compartment = wrap_for_same_compartment as
unsafe extern "C" fn(*mut JSContext, *mut JSObject) -> *mut JSObject;
let pre_wrap = pre_wrap as
unsafe extern fn(*mut JSContext, *mut JSObject, *mut JSObject,
libc::c_uint) -> *mut JSObject;
unsafe {
// JS_SetWrapObjectCallbacks clobbers the existing wrap callback,
// and JSCompartment::wrap crashes if that happens. The only way
// to retrieve the default callback is as the result of
// JS_SetWrapObjectCallbacks, which is why we call it twice.
let callback = JS_SetWrapObjectCallbacks((*js_runtime).ptr,
None,
Some(wrap_for_same_compartment),
None);
JS_SetWrapObjectCallbacks((*js_runtime).ptr,
callback,
Some(wrap_for_same_compartment),
Some(pre_wrap));
}
let (devtools_sender, devtools_receiver) = channel();
ScriptTask {
page: DOMRefCell::new(None),
incomplete_loads: DOMRefCell::new(vec!()),
image_cache_task: img_cache_task,
resource_task: resource_task,
storage_task: storage_task,
port: port,
chan: chan,
control_chan: control_chan,
control_port: control_port,
constellation_chan: constellation_chan,
compositor: DOMRefCell::new(compositor),
devtools_chan: devtools_chan,
devtools_port: devtools_receiver,
devtools_sender: devtools_sender,
js_runtime: js_runtime,
js_context: DOMRefCell::new(Some(js_context)),
mouse_over_targets: DOMRefCell::new(vec!())
}
}
pub fn new_rt_and_cx() -> (js::rust::rt, Rc<Cx>) {
LiveDOMReferences::initialize();
let js_runtime = js::rust::rt();
assert!({
let ptr: *mut JSRuntime = (*js_runtime).ptr;
!ptr.is_null()
});
unsafe {
JS_SetExtraGCRootsTracer((*js_runtime).ptr, Some(trace_collections), ptr::null_mut());
}
// Unconstrain the runtime's threshold on nominal heap size, to avoid
// triggering GC too often if operating continuously near an arbitrary
// finite threshold. This leaves the maximum-JS_malloc-bytes threshold
// still in effect to cause periodical, and we hope hygienic,
// last-ditch GCs from within the GC's allocator.
unsafe {
JS_SetGCParameter(js_runtime.ptr, JSGC_MAX_BYTES, u32::MAX);
}
let js_context = js_runtime.cx();
assert!({
let ptr: *mut JSContext = (*js_context).ptr;
!ptr.is_null()
});
js_context.set_default_options_and_version();
js_context.set_logging_error_reporter();
unsafe {
JS_SetGCZeal((*js_context).ptr, 0, JS_DEFAULT_ZEAL_FREQ);
JS_SetExtraGCRootsTracer((*js_runtime).ptr, Some(trace_script_tasks), ptr::null_mut());
}
// Needed for debug assertions about whether GC is running.
if !cfg!(ndebug) {
unsafe {
JS_SetGCCallback(js_runtime.ptr,
Some(debug_gc_callback as unsafe extern "C" fn(*mut JSRuntime, JSGCStatus)));
}
}
(js_runtime, js_context)
}
// Return the root page in the frame tree. Panics if it doesn't exist.
pub fn root_page(&self) -> Rc<Page> {
self.page.borrow().as_ref().unwrap().clone()
}
pub fn get_cx(&self) -> *mut JSContext {
(**self.js_context.borrow().as_ref().unwrap()).ptr
}
/// Starts the script task. After calling this method, the script task will loop receiving
/// messages on its port.
pub fn start(&self) {
while self.handle_msgs() {
// Go on...
}
}
/// Handle incoming control messages.
fn handle_msgs(&self) -> bool {
let roots = RootCollection::new();
let _stack_roots_tls = StackRootTLS::new(&roots);
// Handle pending resize events.
// Gather them first to avoid a double mut borrow on self.
let mut resizes = vec!();
{
let page = self.page.borrow();
if let Some(page) = page.as_ref() {
for page in page.iter() {
// Only process a resize if layout is idle.
let window = page.window().root();
if window.r().layout_is_idle() {
let resize_event = window.r().steal_resize_event();
match resize_event {
Some(size) => resizes.push((window.r().pipeline(), size)),
None => ()
}
}
}
}
}
for (id, size) in resizes.into_iter() {
self.handle_event(id, ResizeEvent(size));
}
enum MixedMessage {
FromConstellation(ConstellationControlMsg),
FromScript(ScriptMsg),
FromDevtools(DevtoolScriptControlMsg),
}
// Store new resizes, and gather all other events.
let mut sequential = vec!();
// Receive at least one message so we don't spinloop.
let mut event = {
let sel = Select::new();
let mut port1 = sel.handle(&self.port);
let mut port2 = sel.handle(&self.control_port);
let mut port3 = sel.handle(&self.devtools_port);
unsafe {
port1.add();
port2.add();
if self.devtools_chan.is_some() {
port3.add();
}
}
let ret = sel.wait();
if ret == port1.id() {
MixedMessage::FromScript(self.port.recv().unwrap())
} else if ret == port2.id() {
MixedMessage::FromConstellation(self.control_port.recv().unwrap())
} else if ret == port3.id() {
MixedMessage::FromDevtools(self.devtools_port.recv().unwrap())
} else {
panic!("unexpected select result")
}
};
// Squash any pending resize, reflow, and mouse-move events in the queue.
let mut mouse_move_event_index = None;
loop {
match event {
// This has to be handled before the ResizeMsg below,
// otherwise the page may not have been added to the
// child list yet, causing the find() to fail.
MixedMessage::FromConstellation(ConstellationControlMsg::AttachLayout(
new_layout_info)) => {
self.handle_new_layout(new_layout_info);
}
MixedMessage::FromConstellation(ConstellationControlMsg::Resize(id, size)) => {
self.handle_resize(id, size);
}
MixedMessage::FromConstellation(ConstellationControlMsg::Viewport(id, rect)) => {
self.handle_viewport(id, rect);
}
MixedMessage::FromConstellation(ConstellationControlMsg::SendEvent(
_,
MouseMoveEvent(_))) => {
match mouse_move_event_index {
None => {
mouse_move_event_index = Some(sequential.len());
sequential.push(event);
}
Some(index) => {
sequential[index] = event
}
}
}
_ => {
sequential.push(event);
}
}
// If any of our input sources has an event pending, we'll perform another iteration
// and check for more resize events. If there are no events pending, we'll move
// on and execute the sequential non-resize events we've seen.
match self.control_port.try_recv() {
Err(_) => match self.port.try_recv() {
Err(_) => match self.devtools_port.try_recv() {
Err(_) => break,
Ok(ev) => event = MixedMessage::FromDevtools(ev),
},
Ok(ev) => event = MixedMessage::FromScript(ev),
},
Ok(ev) => event = MixedMessage::FromConstellation(ev),
}
}
// Process the gathered events.
for msg in sequential.into_iter() {
match msg {
MixedMessage::FromConstellation(ConstellationControlMsg::ExitPipeline(id, exit_type)) => {
if self.handle_exit_pipeline_msg(id, exit_type) {
return false
}
},
MixedMessage::FromConstellation(inner_msg) => self.handle_msg_from_constellation(inner_msg),
MixedMessage::FromScript(inner_msg) => self.handle_msg_from_script(inner_msg),
MixedMessage::FromDevtools(inner_msg) => self.handle_msg_from_devtools(inner_msg),
}
}
true
}
fn handle_msg_from_constellation(&self, msg: ConstellationControlMsg) {
match msg {
ConstellationControlMsg::AttachLayout(_) =>
panic!("should have handled AttachLayout already"),
ConstellationControlMsg::Navigate(pipeline_id, subpage_id, load_data) =>
self.handle_navigate(pipeline_id, Some(subpage_id), load_data),
ConstellationControlMsg::SendEvent(id, event) =>
self.handle_event(id, event),
ConstellationControlMsg::ReflowComplete(id, reflow_id) =>
self.handle_reflow_complete_msg(id, reflow_id),
ConstellationControlMsg::ResizeInactive(id, new_size) =>
self.handle_resize_inactive_msg(id, new_size),
ConstellationControlMsg::Viewport(..) =>
panic!("should have handled Viewport already"),
ConstellationControlMsg::Resize(..) =>
panic!("should have handled Resize already"),
ConstellationControlMsg::ExitPipeline(..) =>
panic!("should have handled ExitPipeline already"),
ConstellationControlMsg::GetTitle(pipeline_id) =>
self.handle_get_title_msg(pipeline_id),
ConstellationControlMsg::Freeze(pipeline_id) =>
self.handle_freeze_msg(pipeline_id),
ConstellationControlMsg::Thaw(pipeline_id) =>
self.handle_thaw_msg(pipeline_id),
ConstellationControlMsg::MozBrowserEventMsg(parent_pipeline_id,
subpage_id,
event) =>
self.handle_mozbrowser_event_msg(parent_pipeline_id,
subpage_id,
event),
ConstellationControlMsg::UpdateSubpageId(containing_pipeline_id,
old_subpage_id,
new_subpage_id) =>
self.handle_update_subpage_id(containing_pipeline_id, old_subpage_id, new_subpage_id),
}
}
fn handle_msg_from_script(&self, msg: ScriptMsg) {
match msg {
ScriptMsg::Navigate(id, load_data) =>
self.handle_navigate(id, None, load_data),
ScriptMsg::TriggerFragment(id, fragment) =>
self.trigger_fragment(id, fragment),
ScriptMsg::FireTimer(TimerSource::FromWindow(id), timer_id) =>
self.handle_fire_timer_msg(id, timer_id),
ScriptMsg::FireTimer(TimerSource::FromWorker, _) =>
panic!("Worker timeouts must not be sent to script task"),
ScriptMsg::ExitWindow(id) =>
self.handle_exit_window_msg(id),
ScriptMsg::DOMMessage(..) =>
panic!("unexpected message"),
ScriptMsg::RunnableMsg(runnable) =>
runnable.handler(),
ScriptMsg::MainThreadRunnableMsg(runnable) =>
runnable.handler(self),
ScriptMsg::RefcountCleanup(addr) =>
LiveDOMReferences::cleanup(self.get_cx(), addr),
ScriptMsg::PageFetchComplete(id, subpage, response) =>
self.handle_page_fetch_complete(id, subpage, response),
}
}
fn handle_msg_from_devtools(&self, msg: DevtoolScriptControlMsg) {
let page = self.root_page();
match msg {
DevtoolScriptControlMsg::EvaluateJS(id, s, reply) =>
devtools::handle_evaluate_js(&page, id, s, reply),
DevtoolScriptControlMsg::GetRootNode(id, reply) =>
devtools::handle_get_root_node(&page, id, reply),
DevtoolScriptControlMsg::GetDocumentElement(id, reply) =>
devtools::handle_get_document_element(&page, id, reply),
DevtoolScriptControlMsg::GetChildren(id, node_id, reply) =>
devtools::handle_get_children(&page, id, node_id, reply),
DevtoolScriptControlMsg::GetLayout(id, node_id, reply) =>
devtools::handle_get_layout(&page, id, node_id, reply),
DevtoolScriptControlMsg::ModifyAttribute(id, node_id, modifications) =>
devtools::handle_modify_attribute(&page, id, node_id, modifications),
DevtoolScriptControlMsg::WantsLiveNotifications(pipeline_id, to_send) =>
devtools::handle_wants_live_notifications(&page, pipeline_id, to_send),
}
}
fn handle_resize(&self, id: PipelineId, size: WindowSizeData) {
let page = self.page.borrow();
if let Some(ref page) = page.as_ref() {
if let Some(ref page) = page.find(id) {
let window = page.window().root();
window.r().set_resize_event(size);
return;
}
}
let mut loads = self.incomplete_loads.borrow_mut();
if let Some(ref mut load) = loads.iter_mut().find(|load| load.pipeline_id == id) {
load.window_size = Some(size);
return;
}
panic!("resize sent to nonexistent pipeline");
}
fn handle_viewport(&self, id: PipelineId, rect: Rect<f32>) {
let page = self.page.borrow();
if let Some(page) = page.as_ref() {
if let Some(ref inner_page) = page.find(id) {
let window = inner_page.window().root();
if window.r().set_page_clip_rect_with_new_viewport(rect) {
let page = get_page(page, id);
self.force_reflow(&*page, ReflowReason::Viewport);
}
return;
}
}
let mut loads = self.incomplete_loads.borrow_mut();
if let Some(ref mut load) = loads.iter_mut().find(|load| load.pipeline_id == id) {
load.clip_rect = Some(rect);
return;
}
panic!("Page rect message sent to nonexistent pipeline");
}
/// Handle a request to load a page in a new child frame of an existing page.
fn handle_new_layout(&self, new_layout_info: NewLayoutInfo) {
let NewLayoutInfo {
containing_pipeline_id,
new_pipeline_id,
subpage_id,
layout_chan,
load_data,
} = new_layout_info;
let page = self.root_page();
let parent_page = page.find(containing_pipeline_id).expect("ScriptTask: received a layout
whose parent has a PipelineId which does not correspond to a pipeline in the script
task's page tree. This is a bug.");
let parent_window = parent_page.window().root();
let chan = layout_chan.downcast_ref::<Sender<layout_interface::Msg>>().unwrap();
let layout_chan = LayoutChan(chan.clone());
// Kick off the fetch for the new resource.
let new_load = InProgressLoad::new(new_pipeline_id, Some((containing_pipeline_id, subpage_id)),
layout_chan, parent_window.r().window_size(),
load_data.url.clone());
self.start_page_load(new_load, load_data);
}
/// Handles a timer that fired.
fn handle_fire_timer_msg(&self, id: PipelineId, timer_id: TimerId) {
let page = self.root_page();
let page = page.find(id).expect("ScriptTask: received fire timer msg for a
pipeline ID not associated with this script task. This is a bug.");
let window = page.window().root();
window.r().handle_fire_timer(timer_id);
}
/// Handles freeze message
fn handle_freeze_msg(&self, id: PipelineId) {
let page = self.root_page();
let page = page.find(id).expect("ScriptTask: received freeze msg for a
pipeline ID not associated with this script task. This is a bug.");
let window = page.window().root();
window.r().freeze();
}
/// Handles thaw message
fn handle_thaw_msg(&self, id: PipelineId) {
// We should only get this message when moving in history, so all pages requested
// should exist.
let page = self.root_page().find(id).unwrap();
let needed_reflow = page.set_reflow_status(false);
if needed_reflow {
self.force_reflow(&*page, ReflowReason::CachedPageNeededReflow);
}
let window = page.window().root();
window.r().thaw();
}
/// Handles a mozbrowser event, for example see:
/// https://developer.mozilla.org/en-US/docs/Web/Events/mozbrowserloadstart
fn handle_mozbrowser_event_msg(&self,
parent_pipeline_id: PipelineId,
subpage_id: SubpageId,
event: MozBrowserEvent) {
let borrowed_page = self.root_page();
let frame_element = borrowed_page.find(parent_pipeline_id).and_then(|page| {
let doc = page.document().root();
let doc: JSRef<Node> = NodeCast::from_ref(doc.r());
doc.traverse_preorder()
.filter_map(HTMLIFrameElementCast::to_ref)
.find(|node| node.subpage_id() == Some(subpage_id))
.map(Temporary::from_rooted)
}).root();
if let Some(frame_element) = frame_element {
frame_element.r().dispatch_mozbrowser_event(event);
}
}
fn handle_update_subpage_id(&self,
containing_pipeline_id: PipelineId,
old_subpage_id: SubpageId,
new_subpage_id: SubpageId) {
let borrowed_page = self.root_page();
let frame_element = borrowed_page.find(containing_pipeline_id).and_then(|page| {
let doc = page.document().root();
let doc: JSRef<Node> = NodeCast::from_ref(doc.r());
doc.traverse_preorder()
.filter_map(HTMLIFrameElementCast::to_ref)
.find(|node| node.subpage_id() == Some(old_subpage_id))
.map(Temporary::from_rooted)
}).root();
frame_element.unwrap().r().update_subpage_id(new_subpage_id);
}
/// Handles a notification that reflow completed.
fn handle_reflow_complete_msg(&self, pipeline_id: PipelineId, reflow_id: u32) {
debug!("Script: Reflow {:?} complete for {:?}", reflow_id, pipeline_id);
let page = self.root_page();
let page = page.find(pipeline_id).expect(
"ScriptTask: received a load message for a layout channel that is not associated \
with this script task. This is a bug.");
let window = page.window().root();
window.r().handle_reflow_complete_msg(reflow_id);
let doc = page.document().root();
let html_element = doc.r().GetDocumentElement().root();
let reftest_wait = html_element.r().map_or(false, |elem| elem.has_class(&Atom::from_slice("reftest-wait")));
if !reftest_wait {
self.compositor.borrow_mut().set_ready_state(pipeline_id, FinishedLoading);
}
}
/// Window was resized, but this script was not active, so don't reflow yet
fn handle_resize_inactive_msg(&self, id: PipelineId, new_size: WindowSizeData) {
let page = self.root_page();
let page = page.find(id).expect("Received resize message for PipelineId not associated
with a page in the page tree. This is a bug.");
let window = page.window().root();
window.r().set_window_size(new_size);
page.set_reflow_status(true);
}
/// We have gotten a window.close from script, which we pass on to the compositor.
/// We do not shut down the script task now, because the compositor will ask the
/// constellation to shut down the pipeline, which will clean everything up
/// normally. If we do exit, we will tear down the DOM nodes, possibly at a point
/// where layout is still accessing them.
fn handle_exit_window_msg(&self, _: PipelineId) {
debug!("script task handling exit window msg");
// TODO(tkuehn): currently there is only one window,
// so this can afford to be naive and just shut down the
// compositor. In the future it'll need to be smarter.
self.compositor.borrow_mut().close();
}
/// We have received notification that the response associated with a load has completed.
/// Kick off the document and frame tree creation process using the result.
fn handle_page_fetch_complete(&self, id: PipelineId, subpage: Option<SubpageId>,
response: LoadResponse) {
// Any notification received should refer to an existing, in-progress load that is tracked.
let idx = self.incomplete_loads.borrow().iter().position(|load| {
load.pipeline_id == id && load.parent_info.map(|info| info.1) == subpage
}).unwrap();
let load = self.incomplete_loads.borrow_mut().remove(idx);
self.load(response, load);
}
/// Handles a request for the window title.
fn handle_get_title_msg(&self, pipeline_id: PipelineId) {
let page = get_page(&self.root_page(), pipeline_id);
let document = page.document().root();
document.r().send_title_to_compositor();
}
/// Handles a request to exit the script task and shut down layout.
/// Returns true if the script task should shut down and false otherwise.
fn handle_exit_pipeline_msg(&self, id: PipelineId, exit_type: PipelineExitType) -> bool {
// If root is being exited, shut down all pages
let page = self.root_page();
let window = page.window().root();
if window.r().pipeline() == id {
debug!("shutting down layout for root page {:?}", id);
// To ensure the elements of the DOM tree remain usable (such as the window global),
// don't free the JS context until all interactions with it are finished.
shut_down_layout(&page, exit_type);
*self.js_context.borrow_mut() = None;
return true
}
// otherwise find just the matching page and exit all sub-pages
if let Some(ref mut child_page) = page.remove(id) {
shut_down_layout(&*child_page, exit_type);
}
return false;
}
/// The entry point to document loading. Defines bindings, sets up the window and document
/// objects, parses HTML and CSS, and kicks off initial layout.
fn load(&self, response: LoadResponse, incomplete: InProgressLoad) {
let final_url = response.metadata.final_url.clone();
debug!("ScriptTask: loading {} on page {:?}", incomplete.url.serialize(), incomplete.pipeline_id);
// We should either be initializing a root page or loading a child page of an
// existing one.
let root_page_exists = self.page.borrow().is_some();
let frame_element = incomplete.parent_info.and_then(|(parent_id, subpage_id)| {
// The root page may not exist yet, if the parent of this frame
// exists in a different script task.
let borrowed_page = self.page.borrow();
// In the case a parent id exists but the matching page
// cannot be found, this means the page exists in a different
// script task (due to origin) so it shouldn't be returned.
// TODO: window.parent will continue to return self in that
// case, which is wrong. We should be returning an object that
// denies access to most properties (per
// https://github.com/servo/servo/issues/3939#issuecomment-62287025).
borrowed_page.as_ref().and_then(|borrowed_page| {
borrowed_page.find(parent_id).and_then(|page| {
let doc = page.document().root();
let doc: JSRef<Node> = NodeCast::from_ref(doc.r());
doc.traverse_preorder()
.filter_map(HTMLIFrameElementCast::to_ref)
.find(|node| node.subpage_id() == Some(subpage_id))
.map(ElementCast::from_ref)
.map(Temporary::from_rooted)
})
})
}).root();
self.compositor.borrow_mut().set_ready_state(incomplete.pipeline_id, Loading);
let cx = self.js_context.borrow();
let cx = cx.as_ref().unwrap();
// Create a new frame tree entry.
let page = Rc::new(Page::new(incomplete.pipeline_id, final_url.clone()));
if !root_page_exists {
// We have a new root frame tree.
*self.page.borrow_mut() = Some(page.clone());
} else if let Some((parent, _)) = incomplete.parent_info {
// We have a new child frame.
let parent_page = self.root_page();
// TODO(gw): This find will fail when we are sharing script tasks
// between cross origin iframes in the same TLD.
parent_page.find(parent).expect("received load for subpage with missing parent");
parent_page.children.borrow_mut().push(page.clone());
}
enum PageToRemove {
Root,
Child(PipelineId),
}
struct AutoPageRemover<'a> {
page: PageToRemove,
script_task: &'a ScriptTask,
neutered: bool,
}
impl<'a> AutoPageRemover<'a> {
fn new(script_task: &'a ScriptTask, page: PageToRemove) -> AutoPageRemover<'a> {
AutoPageRemover {
page: page,
script_task: script_task,
neutered: false,
}
}
fn neuter(&mut self) {
self.neutered = true;
}
}
#[unsafe_destructor]
impl<'a> Drop for AutoPageRemover<'a> {
fn drop(&mut self) {
if !self.neutered {
match self.page {
PageToRemove::Root => *self.script_task.page.borrow_mut() = None,
PageToRemove::Child(id) => {
let _ = self.script_task.root_page().remove(id);
}
}
}
}
}
let page_to_remove = if !root_page_exists {
PageToRemove::Root
} else {
PageToRemove::Child(incomplete.pipeline_id)
};
let mut page_remover = AutoPageRemover::new(self, page_to_remove);
// Create the window and document objects.
let window = Window::new(cx.clone(),
page.clone(),
self.chan.clone(),
self.control_chan.clone(),
self.compositor.borrow_mut().dup(),
self.image_cache_task.clone(),
self.resource_task.clone(),
self.storage_task.clone(),
self.devtools_chan.clone(),
self.constellation_chan.clone(),
incomplete.layout_chan,
incomplete.pipeline_id,
incomplete.parent_info,
incomplete.window_size).root();
let last_modified: Option<DOMString> = response.metadata.headers.as_ref().and_then(|headers| {
headers.get().map(|&LastModified(ref tm)| dom_last_modified(tm))
});
let content_type = match response.metadata.content_type {
Some((ref t, ref st)) if t.as_slice().eq_ignore_ascii_case("text") &&
st.as_slice().eq_ignore_ascii_case("plain") => {
Some("text/plain".to_owned())
}
_ => None
};
let document = Document::new(window.r(),
Some(final_url.clone()),
IsHTMLDocument::HTMLDocument,
content_type,
last_modified,
DocumentSource::FromParser).root();
window.r().init_browser_context(document.r(), frame_element.r());
// Create the root frame
page.set_frame(Some(Frame {
document: JS::from_rooted(document.r()),
window: JS::from_rooted(window.r()),
}));
let is_javascript = incomplete.url.scheme == "javascript";
let parse_input = if is_javascript {
let evalstr = incomplete.url.non_relative_scheme_data().unwrap();
let jsval = window.r().evaluate_js_on_global_with_result(evalstr);
let strval = FromJSValConvertible::from_jsval(self.get_cx(), jsval,
StringificationBehavior::Empty);
HTMLInput::InputString(strval.unwrap_or("".to_owned()))
} else {
HTMLInput::InputUrl(response)
};
parse_html(document.r(), parse_input, &final_url, None);
document.r().set_ready_state(DocumentReadyState::Interactive);
self.compositor.borrow_mut().set_ready_state(incomplete.pipeline_id, PerformingLayout);
// Kick off the initial reflow of the page.
debug!("kicking off initial reflow of {:?}", final_url);
document.r().content_changed(NodeCast::from_ref(document.r()),
NodeDamage::OtherNodeDamage);
window.r().reflow(ReflowGoal::ForDisplay, ReflowQueryType::NoQuery, ReflowReason::FirstLoad);
// No more reflow required
page.set_reflow_status(false);
// https://html.spec.whatwg.org/multipage/#the-end step 4
let addr: Trusted<Document> = Trusted::new(self.get_cx(), document.r(), self.chan.clone());
let handler = box DocumentProgressHandler::new(addr.clone(), DocumentProgressTask::DOMContentLoaded);
self.chan.send(ScriptMsg::RunnableMsg(handler)).unwrap();
// We have no concept of a document loader right now, so just dispatch the
// "load" event as soon as we've finished executing all scripts parsed during
// the initial load.
// https://html.spec.whatwg.org/multipage/#the-end step 7
let handler = box DocumentProgressHandler::new(addr, DocumentProgressTask::Load);
self.chan.send(ScriptMsg::RunnableMsg(handler)).unwrap();
window.r().set_fragment_name(final_url.fragment.clone());
let ConstellationChan(ref chan) = self.constellation_chan;
chan.send(ConstellationMsg::LoadComplete).unwrap();
// Notify devtools that a new script global exists.
self.notify_devtools(document.r().Title(), final_url, (incomplete.pipeline_id, None));
page_remover.neuter();
}
fn notify_devtools(&self, title: DOMString, url: Url, ids: (PipelineId, Option<WorkerId>)) {
match self.devtools_chan {
None => {}
Some(ref chan) => {
let page_info = DevtoolsPageInfo {
title: title,
url: url,
};
chan.send(DevtoolsControlMsg::NewGlobal(ids,
self.devtools_sender.clone(),
page_info)).unwrap();
}
}
}
fn scroll_fragment_point(&self, pipeline_id: PipelineId, node: JSRef<Element>) {
let node: JSRef<Node> = NodeCast::from_ref(node);
let rect = node.get_bounding_content_box();
let point = Point2D(to_frac_px(rect.origin.x).to_f32().unwrap(),
to_frac_px(rect.origin.y).to_f32().unwrap());
// FIXME(#2003, pcwalton): This is pretty bogus when multiple layers are involved.
// Really what needs to happen is that this needs to go through layout to ask which
// layer the element belongs to, and have it send the scroll message to the
// compositor.
self.compositor.borrow_mut().scroll_fragment_point(pipeline_id, LayerId::null(), point);
}
/// Reflows non-incrementally.
fn force_reflow(&self, page: &Page, reason: ReflowReason) {
let document = page.document().root();
document.r().dirty_all_nodes();
let window = window_from_node(document.r()).root();
window.r().reflow(ReflowGoal::ForDisplay, ReflowQueryType::NoQuery, reason);
}
/// This is the main entry point for receiving and dispatching DOM events.
///
/// TODO: Actually perform DOM event dispatch.
fn handle_event(&self, pipeline_id: PipelineId, event: CompositorEvent) {
match event {
ResizeEvent(new_size) => {
self.handle_resize_event(pipeline_id, new_size);
}
ReflowEvent(nodes) => {
// FIXME(pcwalton): This event seems to only be used by the image cache task, and
// the interaction between it and the image holder is really racy. I think that, in
// order to fix this race, we need to rewrite the image cache task to make the
// image holder responsible for the lifecycle of image loading instead of having
// the image holder and layout task both be observers. Then we can have the DOM
// image element observe the state of the image holder and have it send reflows
// via the normal dirtying mechanism, and ultimately remove this event.
//
// See the implementation of `Width()` and `Height()` in `HTMLImageElement` for
// fallout of this problem.
for node in nodes.iter() {
let node_to_dirty = node::from_untrusted_node_address(self.js_runtime.ptr,
*node).root();
let page = get_page(&self.root_page(), pipeline_id);
let document = page.document().root();
document.r().content_changed(node_to_dirty.r(),
NodeDamage::OtherNodeDamage);
}
self.handle_reflow_event(pipeline_id);
}
ClickEvent(button, point) => {
let page = get_page(&self.root_page(), pipeline_id);
let document = page.document().root();
document.r().handle_click_event(self.js_runtime.ptr, button, point);
}
MouseDownEvent(..) => {}
MouseUpEvent(..) => {}
MouseMoveEvent(point) => {
let page = get_page(&self.root_page(), pipeline_id);
let document = page.document().root();
let mouse_over_targets = &mut *self.mouse_over_targets.borrow_mut();
document.r().handle_mouse_move_event(self.js_runtime.ptr, point, mouse_over_targets);
}
KeyEvent(key, state, modifiers) => {
let page = get_page(&self.root_page(), pipeline_id);
let document = page.document().root();
document.r().dispatch_key_event(
key, state, modifiers, &mut *self.compositor.borrow_mut());
}
}
}
/// https://html.spec.whatwg.org/multipage/browsers.html#navigating-across-documents
/// The entry point for content to notify that a new load has been requested
/// for the given pipeline (specifically the "navigate" algorithm).
fn handle_navigate(&self, pipeline_id: PipelineId, subpage_id: Option<SubpageId>, load_data: LoadData) {
match subpage_id {
Some(subpage_id) => {
let borrowed_page = self.root_page();
let iframe = borrowed_page.find(pipeline_id).and_then(|page| {
let doc = page.document().root();
let doc: JSRef<Node> = NodeCast::from_ref(doc.r());
doc.traverse_preorder()
.filter_map(HTMLIFrameElementCast::to_ref)
.find(|node| node.subpage_id() == Some(subpage_id))
.map(Temporary::from_rooted)
}).root();
if let Some(iframe) = iframe.r() {
iframe.navigate_child_browsing_context(load_data.url);
}
}
None => {
let ConstellationChan(ref const_chan) = self.constellation_chan;
const_chan.send(ConstellationMsg::LoadUrl(pipeline_id, load_data)).unwrap();
}
}
}
/// The entry point for content to notify that a fragment url has been requested
/// for the given pipeline.
fn trigger_fragment(&self, pipeline_id: PipelineId, fragment: String) {
let page = get_page(&self.root_page(), pipeline_id);
let document = page.document().root();
match document.r().find_fragment_node(fragment).root() {
Some(node) => {
self.scroll_fragment_point(pipeline_id, node.r());
}
None => {}
}
}
fn handle_resize_event(&self, pipeline_id: PipelineId, new_size: WindowSizeData) {
let page = get_page(&self.root_page(), pipeline_id);
let window = page.window().root();
window.r().set_window_size(new_size);
self.force_reflow(&*page, ReflowReason::WindowResize);
let document = page.document().root();
let fragment_node = window.r().steal_fragment_name()
.and_then(|name| document.r().find_fragment_node(name))
.root();
match fragment_node {
Some(node) => self.scroll_fragment_point(pipeline_id, node.r()),
None => {}
}
// http://dev.w3.org/csswg/cssom-view/#resizing-viewports
// https://dvcs.w3.org/hg/dom3events/raw-file/tip/html/DOM3-Events.html#event-type-resize
let uievent = UIEvent::new(window.r(),
"resize".to_owned(), EventBubbles::DoesNotBubble,
EventCancelable::NotCancelable, Some(window.r()),
0i32).root();
let event: JSRef<Event> = EventCast::from_ref(uievent.r());
let wintarget: JSRef<EventTarget> = EventTargetCast::from_ref(window.r());
event.fire(wintarget);
}
fn handle_reflow_event(&self, pipeline_id: PipelineId) {
debug!("script got reflow event");
let page = get_page(&self.root_page(), pipeline_id);
let document = page.document().root();
let window = window_from_node(document.r()).root();
window.r().reflow(ReflowGoal::ForDisplay,
ReflowQueryType::NoQuery,
ReflowReason::ReceivedReflowEvent);
}
/// Initiate a non-blocking fetch for a specified resource. Stores the InProgressLoad
/// argument until a notification is received that the fetch is complete.
fn start_page_load(&self, incomplete: InProgressLoad, mut load_data: LoadData) {
let id = incomplete.pipeline_id.clone();
let subpage = incomplete.parent_info.clone().map(|p| p.1);
let script_chan = self.chan.clone();
let resource_task = self.resource_task.clone();
spawn_named(format!("fetch for {:?}", load_data.url.serialize()), move || {
if load_data.url.scheme == "javascript" {
load_data.url = Url::parse("about:blank").unwrap();
}
let (input_chan, input_port) = channel();
resource_task.send(ControlMsg::Load(NetLoadData {
url: load_data.url,
method: load_data.method,
headers: Headers::new(),
preserved_headers: load_data.headers,
data: load_data.data,
cors: None,
consumer: input_chan,
})).unwrap();
let load_response = input_port.recv().unwrap();
script_chan.send(ScriptMsg::PageFetchComplete(id, subpage, load_response)).unwrap();
});
self.incomplete_loads.borrow_mut().push(incomplete);
}
}
impl Drop for ScriptTask {
fn drop(&mut self) {
SCRIPT_TASK_ROOT.with(|root| {
*root.borrow_mut() = None;
});
}
}
/// Shuts down layout for the given page tree.
fn shut_down_layout(page_tree: &Rc<Page>, exit_type: PipelineExitType) {
let mut channels = vec!();
for page in page_tree.iter() {
// Tell the layout task to begin shutting down, and wait until it
// processed this message.
let (response_chan, response_port) = channel();
let window = page.window().root();
let LayoutChan(chan) = window.r().layout_chan();
if chan.send(layout_interface::Msg::PrepareToExit(response_chan)).is_ok() {
channels.push(chan);
response_port.recv().unwrap();
}
}
// Drop our references to the JSContext and DOM objects.
for page in page_tree.iter() {
let window = page.window().root();
window.r().clear_js_context();
// Sever the connection between the global and the DOM tree
page.set_frame(None);
}
// Destroy the layout task. If there were node leaks, layout will now crash safely.
for chan in channels.into_iter() {
chan.send(layout_interface::Msg::ExitNow(exit_type)).ok();
}
}
pub fn get_page(page: &Rc<Page>, pipeline_id: PipelineId) -> Rc<Page> {
page.find(pipeline_id).expect("ScriptTask: received an event \
message for a layout channel that is not associated with this script task.\
This is a bug.")
}
fn dom_last_modified(tm: &Tm) -> String {
tm.to_local().strftime("%m/%d/%Y %H:%M:%S").unwrap().to_string()
}