Mar 11

“Start Faster” Addon

A large proportion of our startup time is spent on loading the Firefox library(.dll, etc) files. This is true on all of our platforms. In my previous post I thought I discovered a way to load the Firefox binaries more efficiently on Windows(bug 627591). Further testing revealed that to not be true in all cases and that the Windows Prefetch service was still killing our startup speed. Microsoft does not seem to provide a way to opt out of the Windows Prefetch ‘service’.

There is a DIY way to opt out of prefetch by gaining Administrator privileges and deleting files out of the prefetch directory. Our is plan is to provide a Windows service to handle Firefox updates (bug 481815). Additionally the service would be able to do useful things like delete prefetch files, defragment Firefox databases(or at least help report on fragmentation levels). This is all tricky stuff.

In the meantime, to test my theory I wrote a test extension. This is a restartless extension that adds a Windows service and a wrapper executable to significantly speed up Firefox startup after rebooting (oh the irony!). After installing the extension, “Faster Firefox” shortcut on the Desktop should result in up to 2x speed up in Firefox startup. This addon is a rough proof of concept to play with while I bake this functionality into Firefox. Comments, improvements are welcome. Note that launching Firefox by shortcuts other “Faster Firefox” is slower while this extension is installed (this will be fixed once preloading functionality is integrated into Firefox properly). This addon does not yet work on XP because I do not yet have an XP enviroment to test/develop in (patches are welcome).