Edit report at https://bugs.php.net/bug.php?id=60836&edit=1
ID: 60836
Comment by: carloschilazo at gmail dot com
Reported by: oliver at hofff dot com
Summary: Improve array_intersect_key performance
Status: Open
Type: Feature/Change Request
Package: Arrays related
PHP Version: Irrelevant
Block user comment: N
Private report: N
New Comment:
we cant start walking the shortest array given, because we first need to know
which elements we need to look in the other arrays, and those are the ones
presesnt in the first array
" returns an array containing all the entries of array1 which have keys that
are
present in all the arguments. "
Previous Comments:
------------------------------------------------------------------------
[2012-01-22 00:34:49] oliver at hofff dot com
Description:
------------
The trivial test script below runs longer than the extpected "instant"
execution (lot longer).
This is because the algorithm walks the first argument and looks up the key in
every other array supplied as an argument.
Instead it should walk the shortest array given, and look up the keys in every
other array.
Maybe this issue or similar ones also apply to other array functions, which
perform set operations, but I have not checked the code of them.
Of course the optimization could be done in userland, but that feels not right.
Test script:
---------------
$arr = array_fill(0, 1000000, '...');
$i = 1000;
while($i--) {
array_intersect_key($arr, array());
}
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=60836&edit=1
