array_shift() and reindexing View as Markdown

It seems 7-8 times slower than array_shift() and that is even without a
way to fetch the first value.

I tried
$array = array_slice($array, 1)
and
$array = array_slice($array, 1, NULL, true);

-- Jille

Op 12-07-12 14:39, David Muir schreef:

What about replacing the existing array with array_slice?

David

Hello,

array_shift() currently reindexes the array after shifting one element. The reindexing has quite some impact on it's performance. I would like to suggest an extra parameter to array_shift() which can be used to prevent reindexing.

From a few quick (and sloppy!) tests I get these results:
reset($array); list($key, $value) = each($array); unset($array[$key]); is ~50-150 times faster than array_shift().
Calling array_reverse() and using array_pop() is ~2000-5000 times faster.

If you agree this would be an useful addition I will create a patch.

-- Jille

Op 12-07-12 15:18, Johannes Schlüter schreef:

Hello,

array_shift() currently reindexes the array after shifting one element.
The reindexing has quite some impact on it's performance. I would like
to suggest an extra parameter to array_shift() which can be used to
prevent reindexing.

From a few quick (and sloppy!) tests I get these results:
reset($array); list($key, $value) = each($array); unset($array[$key]); is ~50-150 times faster than array_shift().
Calling array_reverse() and using array_pop() is ~2000-5000 times faster.

If you agree this would be an useful addition I will create a patch.
I haven't checked this, but is the difference only due to the re-hashing
or also due to the fact that that array_shift() is taking the array by
reference and therefore making a copy during the call if other
cow-references (refcount>1, isref=0) exist?
If I disable the reindexing code array_shift() becomes ~300 times faster.

-- Jille