168515 - [pref][perf] combine default pref files into one at install time

Status: VERIFIED DUPLICATE of bug 66877

(SeaMonkey :: General, defect)

Description

[(not reading, please use [e-mail] instead)]

in another bug, dveditz wrote that having a bunch of pref default files:  

"hurts performance, because a browser-only install then has to parse extra pref 
files at startup. But then supposedly profile migration doesn't work right if 
the mailnews pref defaults aren't present, and then if the user later wants to 
add mail there is no way to migrate mail. Sounds weak to me, but that was the 
excuse at the time."

unless you want to spend time re-writing migration (you don't), here's a way to 
solve the perf problem:

in the tree have seperate js files.  but in the installed default/prefs dir, 
have one.  so we pay for the hit at install time, not at startup each time.

at install time, instead of copying files to deafult/prefs, cat them to one 
all.js file.

Comment 1

[(not reading, please use [e-mail] instead)]

see http://bugzilla.mozilla.org/show_bug.cgi?id=165626#c18

Comment 2

[(not reading, please use [e-mail] instead)]

before we do any work, we should see just how much time we'll save.

we can estimate by taking a build, and doing:

cat *.js > foo
rm *.js
mv foo all.js

and comparing the pref win.

after that, if you think mailnews.js is weighing down all.js and affecting 
startup (let's see numbers), we could discuss how to fix migration.

we might just need the fat all.js for migration, but the just old all.js (minus 
mailnews.js) for browser only.

my guess tells me that the numbers will show we shouldn't do anything.

Comment 3

[(not reading, please use [e-mail] instead)]

keep in mind the platform specific files:

../modules/libpref/src/beos/beos.js      ../modules/libpref/src/os2/os2pref.js
../modules/libpref/src/init/all.js       ../modules/libpref/src/unix/openvms.js
../modules/libpref/src/init/editor.js    ../modules/libpref/src/unix/photon.js
../modules/libpref/src/init/mailnews.js  ../modules/libpref/src/unix/unix.js
../modules/libpref/src/mac/macprefs.js   ../modules/libpref/src/win/winpref.js

and, the pref files from the ns tree, like mailnews-ns.js that overrides 
mailnews.js

so if we cat, we have to keep the end result the same.

Comment 4

[Daniel Veditz [:dveditz]]

*** This bug has been marked as a duplicate of 66877 ***

Comment 5

[timeless]

vrfy dupe