Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:87212
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain googlemail.com designates 209.85.212.173 as permitted sender)
MIME-Version: 1.0
Date: Mon, 20 Jul 2015 17:29:57 +0100
Message-ID: <CAFKaYMpJfkUWGvSgEYo0xVsQvn-_rK+gJCAfwUxhwEdU7HimCA@mail.gmail.com>
To: internals@lists.php.net
Content-Type: multipart/alternative; boundary=089e0103defa5e4593051b510c5d
Subject: Expanded variable hash function
From: codekestrel@googlemail.com (Dominic Grostate)

--089e0103defa5e4593051b510c5d
Content-Type: text/plain; charset=UTF-8

Hi all.  I've been experimenting with creating data structures in PHP.  For
example I implemented a HashSet which turns out to have a higher
performance on larger sets than running in_array on arrays on add.

To do this I has to create a hash code generator which could hash scalar
types and objects.  Other arrays and resources are invalid in my experiment
for use as keys.

I'd like to request a feature alternative to spl_object_hash that can
safely hash any value save the two types I mentioned.

The issue with simply hashing a string to sha1 and sha1ing the result of
spl_object_hash is the possibility of collisions since a string can be
equal to the hash of an object.  This requires salting the values with
something defining their types, which is what I have done.

However my solution, although relatively fast, feels very unconventional,
and desires a natively supported option.

Thanks,
Dominic

--089e0103defa5e4593051b510c5d--