1845445 - Make `ContentEventHandler::ShouldBreakLineBefore` stop using `IsAnyOfHTMLElements`

Status: RESOLVED FIXED

(Core :: DOM: UI Events & Focus Handling, defect, P2)

Description

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

The call is with 30 params and it appears in the profile. Additionally, the call of do_QueryObject also appears in the profile.

With using nsHTMLTags, we can solve these performance issue with the cost of accessing the hash table.

Comment 1

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

Attachment: Bug 1845445 - Make `ContentEventHandler::ShouldBreakLineBefore` use `nsHTMLTag` instead of `nsINode::IsAnyOfHTMLElements` with a lot of params r=smaug!,#dom-core

It's expensive to call nsINode::IsAnyOfHTMLElements with a lot of arguments
due to its recursive calls (in this case, called with 30 arguments).

Additionally, the unknown element check with do_QueryObject is also expensive.

Once we get an nsHTMLTag, we can use a switch statement.

Note that I realized nsHTMLTag_small is not defined only on Windows if
nsHTMLTags.h is included after rpcndr.h in the Windows SDK since there is

#define small char

In the header file. This patch includes the workaround for this issue.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/25a29224e55d
Make `ContentEventHandler::ShouldBreakLineBefore` use `nsHTMLTag` instead of `nsINode::IsAnyOfHTMLElements` with a lot of params r=smaug

Comment 3

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/25a29224e55d