Either directly or with a new API we could do with a means of caching JS loaded through loadSubScript, see bug 648124 for a prime use.
Created attachment 524525 [details] [diff] [review] WIP: Cache subscripts in startupcache Patch based on tracemonkey tip. Needs a bit more cleanup but it should work if someone wants to take this and measure how much time we save on bootstrap.js when cached.
Created attachment 527150 [details] [diff] [review] Cache subscripts in startupcache This one passes tests.
Thank you, I've been meaning to file this bug for weeks. This is also important for Jetpack, which loads *all* of its scripts (including the SDK) via evalInSandbox.
Created attachment 538661 [details] [diff] [review] Cache subscripts in startupcache, v2 Updated based on patches in bug 592943
(In reply to comment #3) > Thank you, I've been meaning to file this bug for weeks. > > This is also important for Jetpack, which loads *all* of its scripts > (including the SDK) via evalInSandbox. Oh yeah, jetpack was one of the reasons I worked on this. Are you working on/looking at jetpack startup perf? I can get you a build with caching so you can see how much it helps jetpack if you want to do some measurements.
Once bug 481603 is fixed I wonder if there might be a bunch of benefits in switching jetpack to use modules where possible to save multiple add-ons using the same version of the SDK having to load the same script multiple times. Would have to be some careful manual refcounting or something to make it useful though I guess
Created attachment 539104 [details] [diff] [review] Cache subscripts in startupcache, v3 New version which is dependent on the cache invalidation stuff in bug 481603.
Created attachment 539408 [details] [diff] [review] Cache subscripts in startupcache, v4
Created attachment 543034 [details] [diff] [review] Cache subscripts in startupcache, v5 Remove some unused includes.
Comment on attachment 543034 [details] [diff] [review] Cache subscripts in startupcache, v5 Looks good, and with this I think you can remove the static ReadScriptFromStream() and WriteScriptToStream() functions from mozJSComponentLoader.cpp too! r=jst with that.
Opps. Guess I completely forgot to remove the original function while trying to move it. Testing on try, will push to m-i once things look ok on try. http://tbpl.mozilla.org/?tree=Try&rev=d36f38e6c687
What release will this land in? It needs to be documented.
Firefox 8, as noted in target milestone. This is just an optimization. Developers don't need to do anything about this.
They do. The various script loading methods are listed on MDC, along with their advantages and disadvantages. The fact this now supports caching can be both an advantage and a disadvantage over other methods, depending on their purposes (especially for developers who rely on getting a fresh load of the script each time it's called).
:kmag updated the docs here: https://developer.mozilla.org/en/XPCOM_Interface_Reference/mozIJSSubScriptLoader#loadSubScript%28%29 I've added a mention to Firefox 8 for developers.
(In reply to comment #18) > :kmag updated the docs here: > > https://developer.mozilla.org/en/XPCOM_Interface_Reference/ > mozIJSSubScriptLoader#loadSubScript%28%29 > > I've added a mention to Firefox 8 for developers. How I can disable caching JS for debugging? The following settings seems nothing effect. user_pref("nglayout.debug.disable_xul_fastload", true); user_pref("nglayout.debug.disable_xul_cache", true);