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Date: Thu, 28 Jul 2016 10:59:00 +0200
To: Xinchen Hui <xinchen.h@zend.com>
Cc: PHP Internals <internals@lists.php.net>
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Message-ID: <20160728090041.3870486@mx.zeyos.com>
Subject: [PHP-DEV] More packed hash optimizations in array.c
From: ben.coutu@zeyos.com (Benjamin Coutu)

Hello Xinchen,=0A=0AI have noticed two more cases where we could easily use=
 packed arrays.=0A=0A1. array_merge($packed1, $packed2, ...):=0A=0AIn the q=
uite common case where all arguments are packed arrays, the resulting array=
 can also be a packed array (as per documentation: "if the input arrays [..=
.] contain numeric keys, the later value will not overwrite the original va=
lue, but will be appended"), thereby ensuring that packed arrays stay packe=
d when appended to one another.=0AIn general we should try to preserve the =
packed characteristics wherever possible.=0A=0A2. array_column($input, $col=
umn_key, $index_key=3Dnull):=0A=0AFor the common case when $index_key=3Dnul=
l, we can just create a packed array.=0AAlso (not related to packing), we c=
ould pre-initialize the return_value array size with array_init_size() if, =
and only if, $column_key=3Dnull.=0A=0APlease let me know your thoughts.=0A=
=0AThanks,=0A=20
Ben
=0A--=20
=0ABejamin Coutu
ben.coutu@zeyos.com

ZeyOS, Inc.
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