If class A is derived from class B, then an instance of class A can be
converted to B via a static cast, so a slower QI is not needed.
Differential Revision: https://phabricator.services.mozilla.com/D6861
--HG--
extra : moz-landing-system : lando
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
We have a minimum requirement of VS 2015 for Windows builds, which supports
the z length modifier for format specifiers. So we don't need SizePrintfMacros.h
any more, and can just use %zu and friends directly everywhere.
MozReview-Commit-ID: 6s78RvPFMzv
--HG--
extra : rebase_source : 009ea39eb4dac1c927aa03e4f97d8ab673de8a0e
This function is an infallible alternative to nsIURI::GetSpec(). It's useful
when it's appropriate to handle a GetSpec() failure with a failure string, e.g.
for log/warning/error messages. It allows code like this:
nsAutoCString spec;
uri->GetSpec(spec);
printf("uri: %s", spec.get());
to be changed to this:
printf("uri: %s", uri->GetSpecOrDefault().get());
This introduces a slight behavioural change. Previously, if GetSpec() failed,
an empty string would be used here. Now, "[nsIURI::GetSpec failed]" will be
produced instead. In most cases this failure string will make for a clearer
log/warning/error message than the empty string.
* * *
Bug 1297961 (part 1b) - More GetSpecOrDefault() additions. r=hurley.
I will fold this into part 1 before landing.
--HG--
extra : rebase_source : ddc19a5624354ac098be019ca13cc24b99b80ddc