- Removed the str_replace() call to replace unescaped line terminators
if UTF8_OK is set. PHP 7.1 and later escape these by default.
The speedup isn't much at all (about 1% in my testing when encoding an
API siteinfo result taken from enwiki). Perhaps it's not surprising
given the way str_replace() works[1]. Still, it's better not to spend
CPU time looking for characters that will not occur.
- Changed the algorithm for the optional spaces-to-tabs conversion when
pretty printing. Instead of replacing one indent level throughout the
entire string before replacing the next level, use a regex to replace
in one pass. This is usually faster now that PHP 7 enables PCRE's JIT
compiler by default. Without JIT, the regex was often slower.
The speedup can be large for deeply nested data. For example, in my
testing the languages/i18n data took about 8% less time to encode as
tab-indented JSON, yet the API site info result took about 45% less.
(This, of course, isn't actually relevant to the API even when pretty
printed output is requested, because ApiFormatJson uses the default
indent string of four spaces, which will always be faster unless
support for tab indentation is added to PHP's json extension.)
- Set options using if statements instead of the ternary operator. This
is the clearer way, and maybe the slightly faster one, skipping the
assignment when the flags do not need to be set.
[1]: https://github.com/php/php-src/blob/PHP-8.0.10/ext/standard/string.c#L2969
Change-Id: Iebb1df0264e335a1819956710eeacf6d6b8f1471
210a34369a