servo/components/script/dom/servohtmlparser.rs
Till Schneidereit a0c5d47910 Improve spec-compliance of script loading and execution during document startup
Including proper support for async and deferred scripts.
2015-10-26 21:35:09 +01:00

362 lines
12 KiB
Rust

/* 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 bulk of the HTML parser integration is in `script::parse::html`.
//! This module is mostly about its interaction with DOM memory management.
use document_loader::LoadType;
use dom::bindings::cell::DOMRefCell;
use dom::bindings::codegen::Bindings::ServoHTMLParserBinding;
use dom::bindings::global::GlobalRef;
use dom::bindings::js::{JS, Root};
use dom::bindings::refcounted::Trusted;
use dom::bindings::trace::JSTraceable;
use dom::bindings::utils::{Reflector, reflect_dom_object};
use dom::document::Document;
use dom::node::Node;
use dom::text::Text;
use dom::window::Window;
use encoding::all::UTF_8;
use encoding::types::{DecoderTrap, Encoding};
use html5ever::tokenizer;
use html5ever::tree_builder;
use html5ever::tree_builder::{NodeOrText, TreeBuilder, TreeBuilderOpts};
use hyper::header::ContentType;
use hyper::mime::{Mime, SubLevel, TopLevel};
use js::jsapi::JSTracer;
use msg::constellation_msg::{PipelineId, SubpageId};
use net_traits::{AsyncResponseListener, Metadata};
use network_listener::PreInvoke;
use parse::Parser;
use script_task::{ScriptChan, ScriptTask};
use std::cell::Cell;
use std::default::Default;
use url::Url;
#[must_root]
#[derive(JSTraceable, HeapSizeOf)]
pub struct Sink {
pub base_url: Option<Url>,
pub document: JS<Document>,
}
impl Sink {
#[allow(unrooted_must_root)] // method is only run at parse time
pub fn get_or_create(&self, child: NodeOrText<JS<Node>>) -> Root<Node> {
match child {
NodeOrText::AppendNode(n) => n.root(),
NodeOrText::AppendText(t) => {
let text = Text::new(t.into(), &self.document);
Root::upcast(text)
}
}
}
}
/// FragmentContext is used only to pass this group of related values
/// into functions.
#[derive(Copy, Clone)]
pub struct FragmentContext<'a> {
pub context_elem: &'a Node,
pub form_elem: Option<&'a Node>,
}
pub type Tokenizer = tokenizer::Tokenizer<TreeBuilder<JS<Node>, Sink>>;
/// The context required for asynchronously fetching a document and parsing it progressively.
pub struct ParserContext {
/// The parser that initiated the request.
parser: Option<Trusted<ServoHTMLParser>>,
/// Is this document a synthesized document for a single image?
is_image_document: bool,
/// The pipeline associated with this document.
id: PipelineId,
/// The subpage associated with this document.
subpage: Option<SubpageId>,
/// The target event loop for the response notifications.
script_chan: Box<ScriptChan + Send>,
/// The URL for this document.
url: Url,
}
impl ParserContext {
pub fn new(id: PipelineId, subpage: Option<SubpageId>, script_chan: Box<ScriptChan + Send>,
url: Url) -> ParserContext {
ParserContext {
parser: None,
is_image_document: false,
id: id,
subpage: subpage,
script_chan: script_chan,
url: url,
}
}
}
impl AsyncResponseListener for ParserContext {
fn headers_available(&mut self, metadata: Metadata) {
let content_type = metadata.content_type.clone();
let parser = ScriptTask::page_fetch_complete(self.id.clone(), self.subpage.clone(),
metadata);
let parser = match parser {
Some(parser) => parser,
None => return,
};
let parser = parser.r();
let win = parser.window();
self.parser = Some(Trusted::new(win.get_cx(), parser, self.script_chan.clone()));
match content_type {
Some(ContentType(Mime(TopLevel::Image, _, _))) => {
self.is_image_document = true;
let page = format!("<html><body><img src='{}' /></body></html>",
self.url.serialize());
parser.pending_input.borrow_mut().push(page);
parser.parse_sync();
}
Some(ContentType(Mime(TopLevel::Text, SubLevel::Plain, _))) => {
// FIXME: When servo/html5ever#109 is fixed remove <plaintext> usage and
// replace with fix from that issue.
// text/plain documents require setting the tokenizer into PLAINTEXT mode.
// This is done by using a <plaintext> element as the html5ever tokenizer
// provides no other way to change to that state.
// Spec for text/plain handling is:
// https://html.spec.whatwg.org/multipage/#read-text
let page = format!("<pre>\u{000A}<plaintext>");
parser.pending_input.borrow_mut().push(page);
parser.parse_sync();
},
_ => {}
}
}
fn data_available(&mut self, payload: Vec<u8>) {
if !self.is_image_document {
// FIXME: use Vec<u8> (html5ever #34)
let data = UTF_8.decode(&payload, DecoderTrap::Replace).unwrap();
let parser = match self.parser.as_ref() {
Some(parser) => parser.root(),
None => return,
};
parser.r().parse_chunk(data);
}
}
fn response_complete(&mut self, status: Result<(), String>) {
let parser = match self.parser.as_ref() {
Some(parser) => parser.root(),
None => return,
};
parser.document.finish_load(LoadType::PageSource(self.url.clone()));
if let Err(err) = status {
debug!("Failed to load page URL {}, error: {}", self.url.serialize(), err);
// TODO(Savago): we should send a notification to callers #5463.
}
parser.r().last_chunk_received.set(true);
if !parser.r().is_suspended() {
parser.r().parse_sync();
}
}
}
impl PreInvoke for ParserContext {
}
#[dom_struct]
pub struct ServoHTMLParser {
reflector_: Reflector,
#[ignore_heap_size_of = "Defined in html5ever"]
tokenizer: DOMRefCell<Tokenizer>,
/// Input chunks received but not yet passed to the parser.
pending_input: DOMRefCell<Vec<String>>,
/// The document associated with this parser.
document: JS<Document>,
/// True if this parser should avoid passing any further data to the tokenizer.
suspended: Cell<bool>,
/// Whether to expect any further input from the associated network request.
last_chunk_received: Cell<bool>,
/// The pipeline associated with this parse, unavailable if this parse does not
/// correspond to a page load.
pipeline: Option<PipelineId>,
}
impl<'a> Parser for &'a ServoHTMLParser {
fn parse_chunk(self, input: String) {
self.document.set_current_parser(Some(self));
self.pending_input.borrow_mut().push(input);
if !self.is_suspended() {
self.parse_sync();
}
}
fn finish(self) {
assert!(!self.suspended.get());
assert!(self.pending_input.borrow().is_empty());
self.tokenizer().borrow_mut().end();
debug!("finished parsing");
self.document.set_current_parser(None);
if let Some(pipeline) = self.pipeline {
ScriptTask::parsing_complete(pipeline);
}
}
}
impl ServoHTMLParser {
#[allow(unrooted_must_root)]
pub fn new(base_url: Option<Url>, document: &Document, pipeline: Option<PipelineId>)
-> Root<ServoHTMLParser> {
let sink = Sink {
base_url: base_url,
document: JS::from_ref(document),
};
let tb = TreeBuilder::new(sink, TreeBuilderOpts {
ignore_missing_rules: true,
.. Default::default()
});
let tok = tokenizer::Tokenizer::new(tb, Default::default());
let parser = ServoHTMLParser {
reflector_: Reflector::new(),
tokenizer: DOMRefCell::new(tok),
pending_input: DOMRefCell::new(vec!()),
document: JS::from_ref(document),
suspended: Cell::new(false),
last_chunk_received: Cell::new(false),
pipeline: pipeline,
};
reflect_dom_object(box parser, GlobalRef::Window(document.window()),
ServoHTMLParserBinding::Wrap)
}
#[allow(unrooted_must_root)]
pub fn new_for_fragment(base_url: Option<Url>, document: &Document,
fragment_context: FragmentContext) -> Root<ServoHTMLParser> {
let sink = Sink {
base_url: base_url,
document: JS::from_ref(document),
};
let tb_opts = TreeBuilderOpts {
ignore_missing_rules: true,
.. Default::default()
};
let tb = TreeBuilder::new_for_fragment(sink,
JS::from_ref(fragment_context.context_elem),
fragment_context.form_elem.map(|n| JS::from_ref(n)),
tb_opts);
let tok_opts = tokenizer::TokenizerOpts {
initial_state: Some(tb.tokenizer_state_for_context_elem()),
.. Default::default()
};
let tok = tokenizer::Tokenizer::new(tb, tok_opts);
let parser = ServoHTMLParser {
reflector_: Reflector::new(),
tokenizer: DOMRefCell::new(tok),
pending_input: DOMRefCell::new(vec!()),
document: JS::from_ref(document),
suspended: Cell::new(false),
last_chunk_received: Cell::new(true),
pipeline: None,
};
reflect_dom_object(box parser, GlobalRef::Window(document.window()),
ServoHTMLParserBinding::Wrap)
}
#[inline]
pub fn tokenizer(&self) -> &DOMRefCell<Tokenizer> {
&self.tokenizer
}
}
impl ServoHTMLParser {
fn parse_sync(&self) {
// This parser will continue to parse while there is either pending input or
// the parser remains unsuspended.
loop {
self.document.reflow_if_reflow_timer_expired();
let mut pending_input = self.pending_input.borrow_mut();
if !pending_input.is_empty() {
let chunk = pending_input.remove(0);
self.tokenizer.borrow_mut().feed(chunk.into());
} else {
self.tokenizer.borrow_mut().run();
}
// Document parsing is blocked on an external resource.
if self.suspended.get() {
return;
}
if pending_input.is_empty() {
break;
}
}
if self.last_chunk_received.get() {
self.finish();
}
}
fn window(&self) -> &Window {
self.document.window()
}
}
impl ServoHTMLParser {
pub fn suspend(&self) {
assert!(!self.suspended.get());
self.suspended.set(true);
}
pub fn resume(&self) {
assert!(self.suspended.get());
self.suspended.set(false);
self.parse_sync();
}
pub fn is_suspended(&self) -> bool {
self.suspended.get()
}
}
struct Tracer {
trc: *mut JSTracer,
}
impl tree_builder::Tracer for Tracer {
type Handle = JS<Node>;
#[allow(unrooted_must_root)]
fn trace_handle(&self, node: JS<Node>) {
node.trace(self.trc);
}
}
impl JSTraceable for Tokenizer {
fn trace(&self, trc: *mut JSTracer) {
let tracer = Tracer {
trc: trc,
};
let tracer = &tracer as &tree_builder::Tracer<Handle=JS<Node>>;
let tree_builder = self.sink();
tree_builder.trace_handles(tracer);
tree_builder.sink().trace(trc);
}
}