js::ObjectOps is often all null. When it's not all null, it's often duplicated
many times among classes. By pulling it out into its own struct, and using a
(possibly null) pointer in js::Class, we can save 208 KiB per process on
64-bit, and half that on 32-bit.
--HG--
extra : rebase_source : 5be8fe45f652392571b8a6d7b63777cbafba6ae4
Using a simple |const char*| is more memory-efficient than allocating a
JS string. We still have to allocate the JS string for passing things
into JS, but ideally we will be able to move the point of allocation
much closer to where it's actually needed, rather than indiscriminantly
doing it all the time.
Note that this does not take into account the exposed/enabled state of the
relevant properties. This should be OK, I hope. Taking that state into account
would be rather annoying, unfortunately. We could make codegen fail if
something is conditionally exposed and unscopable, if desired...
Using a simple |const char*| is more memory-efficient than allocating a
JS string. We still have to allocate the JS string for passing things
into JS, but ideally we will be able to move the point of allocation
much closer to where it's actually needed, rather than indiscriminantly
doing it all the time.
The fields in Prefable relating to disabling are usually all zero. This patch
moves them into a new struct PrefableDisablers. This reduces static data size
by 92 KB, which applies to every process. It might also make isEnabled() faster
because the common case only involves one test instead of two.
--HG--
extra : rebase_source : 004eb8221e23b741c4837dd95af93e437edb4587
In general, using an AutoJSAPI inited with an object is NOT the same as using
AutoSafeJSContext (or AutoJSAPI inited without an object) and then entering the
compartment of the object: the former will report exceptions to the global of
the object as it comes off the stack, while the latter will not. This only
really matters if we have an object from a window or worker global and hence
might fire error events, or report internal stuff to the web console.
The changes to initing with an object made in this bug are OK for the following
reasons:
1) dom/base/Console.cpp: Always clears its exception before coming off the stack.
2) dom/base/nsDOMClassInfo.cpp: Inits with a non-web global.
3) dom/base/nsFrameMessageManager.cpp: Inits with a non-web global.
4) dom/media/MediaPermissionGonk.cpp: We probably want the caller to notice if
anything here throws.
5) dom/xbl/nsXBLPrototypeBinding.cpp: Inits with a non-web global.
6) dom/xul/nsXULElement.cpp: Inits with a non-web global.
7) extensions/pref/autoconfig/src/nsJSConfigTriggers.cpp: Inits with a non-web global.
8) ipc/testshell/XPCShellEnvironment.cpp: Inits with a non-web global.
