Correctness improvements:
* UTF errors are handled safely per spec instead of dangerously truncating
strings.
* There are fewer converter implementations.
Performance improvements:
* The old code did exact buffer length math, which meant doing UTF math twice
on each input string (once for length calculation and another time for
conversion). Exact length math is more complicated when handling errors
properly, which the old code didn't do. The new code does UTF math on the
string content only once (when converting) but risks allocating more than
once. There are heuristics in place to lower the probability of
reallocation in cases where the double math avoidance isn't enough of a
saving to absorb an allocation and memcpy.
* Previously, in UTF-16 <-> UTF-8 conversions, an ASCII prefix was optimized
but a single non-ASCII code point pessimized the rest of the string. The
new code tries to get back on the fast ASCII path.
* UTF-16 to Latin1 conversion guarantees less about handling of out-of-range
input to eliminate an operation from the inner loop on x86/x86_64.
* When assigning to a pre-existing string, the new code tries to reuse the
old buffer instead of first releasing the old buffer and then allocating a
new one.
* When reallocating from the new code, the memcpy covers only the data that
is part of the logical length of the old string instead of memcpying the
whole capacity. (For old callers old excess memcpy behavior is preserved
due to bogus callers. See bug 1472113.)
* UTF-8 strings in XPConnect that are in the Latin1 range are passed to
SpiderMonkey as Latin1.
New features:
* Conversion between UTF-8 and Latin1 is added in order to enable faster
future interop between Rust code (or otherwise UTF-8-using code) and text
node and SpiderMonkey code that uses Latin1.
MozReview-Commit-ID: JaJuExfILM9
* Introduce a setZone method that changes the zone and the freelist.
* leaveAtomsZone() private
--HG--
extra : rebase_source : 7bb624c9091aaa585211577c486288a548926a71
extra : source : 96e57dd562b890bac534d88ff265653d5a00f61c
JS::ubi::Concrete<T> inherits from JS::ubi::Base but not JS::ubi::Node, so the bare 'Size' in the class declaration refers to Base::Size, not Node::Size. (Note that they're the same underlying type.)
--HG--
extra : topic : gcstats.thresh
extra : rebase_source : 2dd9ccca9e458e4f10bdbb8aff58f08732e712c7
This patch series replaces message manager globals with ordinary JS objects
which live in the shared JSM global. Once that happens,
ExecuteInGlobalAndReturnScope will no longer have useful behavior for them,
since the base global has none of the methods that they rely on, and it
provides no way to insert another plain object into the scope chain.
This patch changes the scope chain for frame scripts to instead look like:
-+- Shared JSM global
|
+- LexicalEnvironment[this=global]
|
+- NonSyntacticVariablesObject
|
+- WithEnvironmentObject[target=messageManager]
|
+- LexicalEnvironment[this=messageManager]
Where lexical assignments end up on the lexical scope, and both qualified and
unqualified assignments wind up on the NSVO.
This has some slight behavioral differences from the previous model, in that
properties defined on the message manager can mask properties on the NSVO. But
those differences are minor, and probably not worth worrying about, since
frame scripts are being deprecated as part of the Fission project.
MozReview-Commit-ID: ACEOY2hExco
--HG--
extra : rebase_source : 384ccd422b4167e9a4fc550dd691fcc027553544
Matthew Gaudet
arthur.iakab
Andreea Pavel
Henri Sivonen
Paul Bone
André Bargull
Mike Hommey
Jeff Walden
Steve Fink
Csoregi Natalia
Logan F Smyth
Jon Coppeard
Kris Maglione
Ryan VanderMeulen
Thi Huynh