639231 - separate reset and inherited nsStyleStructID (SID) ranges and store structs in arrays-by-SID rather than structures

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect, P4)

Description

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

In bug 636039, comment 5, I wrote:
>Another thing I realized I can do to make things faster:  reorder style struct
>IDs so the inherited and reset structs have separate ID ranges, and then use
>the IDs as indices into an array in ns{Inherited,Reset}StyleData.

I'm filing this bug on doing that rather than having it all in bug 636039.

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

See bug 636039 comment 11 for performance metrics for these patches.

Comment 2

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Attachment: patch 1: keep reset and inherited style structs IDs separate

Comment 3

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Attachment: patch 2: fix wacky indentation

Comment 4

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Attachment: patch 3: make nsCachedStyleData store arrays indexed by SID

Comment 5

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 517201 [details] [diff] [review]
patch 1: keep reset and inherited style structs IDs separate

Please document that the DUMMY1 and DUMMY2 thing are needed so that the presence of Inherited_Start and Reset_Start won't mess up the actual struct numbering.

r=me

Comment 6

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 517202 [details] [diff] [review]
patch 2: fix wacky indentation

r=me

Comment 7

[Boris Zbarsky [:bzbarsky]]

One note:  The only remaining instance of STYLE_STRUCT_TEST is the Compute*Data calls in WalkRuleTree.  Is there a reason not to just replace that with an array of function pointers?

Comment 8

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 517203 [details] [diff] [review]
patch 3: make nsCachedStyleData store arrays indexed by SID

r=me

Comment 9

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

http://hg.mozilla.org/projects/birch/rev/36b78471344f
http://hg.mozilla.org/projects/birch/rev/b0d6f4e17e2d
http://hg.mozilla.org/projects/birch/rev/329c13fec602

Comment 10

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

https://hg.mozilla.org/mozilla-central/rev/36b78471344f
https://hg.mozilla.org/mozilla-central/rev/b0d6f4e17e2d
https://hg.mozilla.org/mozilla-central/rev/329c13fec602