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
This is the servo piece of:
[Bug 1448138](https://bugzilla.mozilla.org/show_bug.cgi?id=1448138) - Rename string DataFlags::SHARED to REFCOUNTED to make it clearer to those reading the code. r=erahm
This is a renaming in the internals of Gecko's string library that should also have a corresponding rename in the rust bindings. This is already reviewed as part of the Gecko change, and the two pieces should be able to land separately.
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Source-Repo: https://github.com/servo/servo
Source-Revision: 1fda5d6a5a7dabbd80bc9efdedaadfeb9bf9e93a
--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
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---
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Source-Revision: 5d209a70ab11cd0ce6c7e086091112570c6e259d
--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : c837bee3dbbf93357f6553a2a356685a094d8e3e
We already have https://github.com/servo/servo/pull/19612 to deny warnings at the time of landing into master. But it’s not useful to break the build when later compiler with a more recent Rust version that has introduced new warnings:
https://bugzilla.mozilla.org/show_bug.cgi?id=1434619
Source-Repo: https://github.com/servo/servo
Source-Revision: 7546c37f1e921a112fef5828c59c6738a98c3f30
--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : ed5c34f72e321ce0051347bd5156389d1ef26bef
See #18809
Still haven't had time to test it but it should fix the tests failures that appeared in m-c
Source-Repo: https://github.com/servo/servo
Source-Revision: fe4139b779b3af749ec1426ddf4e1393c7b85442
--HG--
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : 9a0549d7dd8a99315ba3f8eec5d0f9fdf9eb4c0f
This is the servo side of bug 1403213.
Take 2 of #18941 which got backed out because we botched the landing of the gecko side and I wasn't able to fix it in time.
Source-Repo: https://github.com/servo/servo
Source-Revision: 0e6946fd9c279425e66721e6eb2b1e323e4c640f
--HG--
rename : servo/components/style/gecko_bindings/nsstring_vendor/src/lib.rs => servo/support/gecko/nsstring/src/lib.rs
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : 6d2fb196b2ed25c0201097d20e07b2e757096d00
This is the servo side of bug 1403213.
This cannot merge until https://bugzilla.mozilla.org/show_bug.cgi?id=1377351 merges. It is currently on inbound. This will break autoland when it merges until the gecko-side part has also landed.
Source-Repo: https://github.com/servo/servo
Source-Revision: 7e0f5afa83d9f0eba07988735e56f47a2c18b451
--HG--
rename : servo/components/style/gecko_bindings/nsstring_vendor/src/lib.rs => servo/support/gecko/nsstring/src/lib.rs
extra : subtree_source : https%3A//hg.mozilla.org/projects/converted-servo-linear
extra : subtree_revision : ee57178ea85a844d5fb5c15e9aab3d430c0ac9a1
Henri Sivonen
Bobby Holley
L. David Baron
janczer
Simon Sapin
Bastien Orivel
Nika Layzell
Gregory Szorc
Sebastian Hengst