74655 - 40% of reply time in mailcompose spent converting linefeeds

Status: VERIFIED FIXED

(Core :: DOM: Editor, defect, P2)

Description

[David Hyatt]

40% of reply time on large messages is spent in ReplaceSubstring.  The original
caller of this method is in the mailcompose code.  It is called TranslateLineBreaks.

This function should first be removed from mail compose, but even after it is
gone, editor does this conversion in nsHTMLDataTransfer.  Just grep for the four
occurrences of ReplaceSubstring in the editor code.

This linefeed conversion should be done without performing a replace, since you
end up thrashing in memmove.

Comment 1

[rubydoo123]

assigning to jfrancis

Comment 2

[Simon Fraser [no longer active]]

I checked in mozilla/xpcom/io/nsLinebreakConverter.cpp/h a long time ago which 
does efficient linebreak conversions on strings (though the nsString version 
doesn't work on nsAutoStrings).

It seems that the right thing to do would be to rewrite these to use some of the 
new string class goodness, and encourage their use everywhere.

Comment 3

[Simon Fraser [no longer active]]

Places that do inefficient linebreak conversions:

/editor/base/nsHTMLEditor.cpp, line 918 -- 
inputString.ReplaceSubstring(NS_ConvertASCIItoUCS2("\r\n"),
/editor/base/nsHTMLDataTransfer.cpp, line 199 -- 
inputString.ReplaceSubstring(NS_ConvertASCIItoUCS2("\r\n"),
/htmlparser/src/nsViewSourceHTML.cpp, line 1185 -- 
theStr.ReplaceSubstring(NS_ConvertASCIItoUCS2("\r\n"), NS_ConvertASCIItoUCS2("\
n"));
/layout/html/forms/src/nsFormControlHelper.cpp, line 122 -- 
aString.ReplaceSubstring(NS_ConvertASCIItoUCS2("\r\n"),
NS_ConvertASCIItoUCS2("\n"));
/mailnews/compose/src/nsMsgCompUtils.cpp, line 2069 -- 
aInString.ReplaceSubstring(NS_ConvertASCIItoUCS2(CRLF),
NS_ConvertASCIItoUCS2(LF));

Comment 4

[Joe Francis]

simon: do your converters work with the new string api's?

hyatt: I beelieve i can avoid this whole issue in the work I'm doing now.  I have 
to go thrugh the string a character at a time anyway to do whitespace conversion.  
I can look for crlf's etc on the way and treat them all as needed.

Comment 5

[Simon Fraser [no longer active]]

Joe: no. Nor do they work with nsAutoStrings.

Comment 6

[Jean-Francois Ducarroz]

the message compose part is covered by bug 74901

Comment 7

[Joe Francis]

fix checked in

Comment 8

[Joe Francis]

v=jfrancis