Rewrite the style sharing candidate cache.

The style candidate cache had regressed a few times (see #12534), and my
intuition is that being able to disable all style sharing with a single rule in
the page is really unfortunate.

This commit redesigns the style sharing cache in order to be a optimistic cache,
but then reject candidates if they match different sibling-affecting selectors
in the page, for example.

So far the numbers have improved, but not so much as I'd wanted (~10%/20% of
non-incremental restyling time in general). The current implementation is really
dumb though (we recompute and re-match a lot of stuff), so we should be able to
optimise it quite a bit.

I have different ideas for improving it (that may or may not work), apart of the
low-hanging fruit like don't re-matching candidates all the time but I have to
measure the real impact.

Also, I need to verify it against try.
This commit is contained in:
Emilio Cobos Álvarez 2016-07-29 17:24:12 -07:00
parent ec53136863
commit 3af774bd75
No known key found for this signature in database
GPG key ID: 056B727BB9C1027C
23 changed files with 467 additions and 236 deletions

View file

@ -172,6 +172,9 @@ pub struct Opts {
/// Whether Style Sharing Cache is used
pub disable_share_style_cache: bool,
/// Whether to show in stdout style sharing cache stats after a restyle.
pub style_sharing_stats: bool,
/// Translate mouse input into touch events.
pub convert_mouse_to_touch: bool,
@ -275,6 +278,9 @@ pub struct DebugOptions {
/// Disable the style sharing cache.
pub disable_share_style_cache: bool,
/// Whether to show in stdout style sharing cache stats after a restyle.
pub style_sharing_stats: bool,
/// Translate mouse input into touch events.
pub convert_mouse_to_touch: bool,
@ -331,6 +337,7 @@ impl DebugOptions {
"paint-flashing" => debug_options.paint_flashing = true,
"trace-layout" => debug_options.trace_layout = true,
"disable-share-style-cache" => debug_options.disable_share_style_cache = true,
"style-sharing-stats" => debug_options.style_sharing_stats = true,
"convert-mouse-to-touch" => debug_options.convert_mouse_to_touch = true,
"replace-surrogates" => debug_options.replace_surrogates = true,
"gc-profile" => debug_options.gc_profile = true,
@ -512,6 +519,7 @@ pub fn default_opts() -> Opts {
profile_script_events: false,
profile_heartbeats: false,
disable_share_style_cache: false,
style_sharing_stats: false,
convert_mouse_to_touch: false,
exit_after_load: false,
no_native_titlebar: false,
@ -817,6 +825,7 @@ pub fn from_cmdline_args(args: &[String]) -> ArgumentParsingResult {
dump_layer_tree: debug_options.dump_layer_tree,
relayout_event: debug_options.relayout_event,
disable_share_style_cache: debug_options.disable_share_style_cache,
style_sharing_stats: debug_options.style_sharing_stats,
convert_mouse_to_touch: debug_options.convert_mouse_to_touch,
exit_after_load: opt_match.opt_present("x"),
no_native_titlebar: do_not_use_native_titlebar,