201782 - Reduce NS_LITERAL_STRING usage in editor to reduce code size

Status: RESOLVED INCOMPLETE

(Core :: DOM: Editor, defect)

Description

[Simon Fraser [no longer active]]

nsAString::Equals(NS_LITERAL_STRING("foo")) produces very verbose code.
Converting  to narrow (UTF8) strings and comparing with a literal C string
shrinks the code considerably (see attached data). Since we're only ever
concerned with attribute names in ASCII in editor, maybe we should consider
converting all attribute strings to 8-bit.

Comment 1

[Simon Fraser [no longer active]]

Attachment: Some Piecemeal string changes in editor

Comment 2

[Simon Fraser [no longer active]]

Attachment: Diffs of 'nm' output showing changes in code size

Numbers on the left are compiled size of this method in bytes. Diff shows
function size before, and after the patch. For example:

-    6652 t nsHTMLEditRules::RemoveBlockStyle(nsCOMArray<nsIDOMNode>&)
+    2088 t nsHTMLEditRules::RemoveBlockStyle(nsCOMArray<nsIDOMNode>&)

-    5476 t nsHTMLEditRules::ApplyBlockStyle(nsCOMArray<nsIDOMNode>&, nsAString
const*)
+    2476 t nsHTMLEditRules::ApplyBlockStyle(nsCOMArray<nsIDOMNode>&, nsAString
const*)

Effects of these changes on library size in an opt build:
-rwxr-xr-x  1 smfr  staff  880004 Apr 12 10:43 libeditor_patched.dylib
-rwxr-xr-x  1 smfr  staff  895532 Apr 12 10:11 libeditor_original.dylib

Comment 3

[Simon Fraser [no longer active]]

Attachment: More extensive editor code cleanup

This patch contains more cleanup, not just related to string usage. Changes
include:
* Make data const where possible
* More efficient member var packing (PRPackedBool)
* Tidy up ctor member intialization to fix warnings
* Remove unused static gInstanceCounts
* Clean up nsEditor::GetTextNodeTag (what was buster thinking??)
* Removed the sParserService static in nsHTMLEditor. This had knock-on effects
  of making a bunch of methods non-static, which percolates into the
  nsHTMLEditRules and nsWSRunObject. NodeIsBlockStatic was removed.

Lib size with these changes:
-rwxr-xr-x  1 smfr  staff  895532 Apr 12 10:11 libeditor_orig.dylib
-rwxr-xr-x  1 smfr  staff  873924 Apr 12 14:40 libeditor_patched.dylib

Comment 4

[Kevin McCluskey (gone)]

editorbase-

-> sfraser

Comment 5

[Ludovic Hirlimann [:Usul]]

Simon do you intend to update/check these patches in ?

Comment 6

[Simon Fraser [no longer active]]

No.

Comment 7

[Nathan Froyd [:froydnj]]

The Equals(NS_LITERAL_*(...)) changes are no longer relevant, and editor/ has changed so much in the past decade or so that the size patches are probably irrelevant as well.