On Sun, Nov 22, 2015 at 8:01 AM, Xinchen Hui <larue...@php.net> wrote:
> Hey: > > On Sun, Nov 22, 2015 at 6:47 AM, Anthony Ferrara <ircmax...@gmail.com> > wrote: > > > All, > > > > It appears that in our efforts to optimize PHP 7 we've introduced an > > inconsistency into array handling. This is demonstrated by this > > script: https://3v4l.org/hVcAB > > > > $a = 1; > > unset($a); > > var_dump(count($GLOBALS), $GLOBALS); > > > > The result is that the count doesn't match the contents of the array. > > > > It also affects objects casted to arrays in certain cases. > > > > Here, the array has 1 element, but should have 0. Trying to access the > > "1" element "a" results in a notice. > > > > This means that the count is incorrect. This is due to the fact that > > the "a" element follows an IS_INDIRECT type pointing to the other > > symbol table. > > > > A potential solution would be to make count() an O(n) operation in the > > case that the hashtable is a symbol table or if it has INDIRECT > > elements. Meaning that we'd compute the real count at runtime. > > > > This obviously has performance ramifications, but we shouldn't > > sacrifice consistency and behavior for performance IMHO. Especially > > when it comes to core data structures. > > > > I think this is significant enough to be a blocker to gold and that we > > should fix it prior to release. > > > > I don't think so, it's only affects symbol tables. means, it won't affects > normal arrays. like: > > <?php > > $array = range(1, 10); > unset($array[2]); > var_dump(count($array)); > > > $array = array("foo" => 1, "bar" => 2, "dummy" => 3); > unset($array["bar"]); > var_dump(count($array)); > ?> > > anyway, I've fixed this here: > > https://github.com/php/php-src/commit/eada2aa91add2de69bc5783b840a21243a7b0678 > > and, we maybe move this new functions into zend_hash(as a ZEND_API), > anyway I am not sure whether it's okey for PHP-7.0. > The patch looks fine. We already use something similar for serialise(). Thanks. Dmitry. > > will discuss with welting and Dmitry on Monday. > > thanks > > > > > Thoughts? > > > > Anthony > > > > -- > > PHP Internals - PHP Runtime Development Mailing List > > To unsubscribe, visit: http://www.php.net/unsub.php > > > > > > -- > Xinchen Hui > @Laruence > http://www.laruence.com/ >
