Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:73963
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain gmail.com designates 209.85.192.51 as permitted sender)
MIME-Version: 1.0
In-Reply-To: <CAJZVxRk-xBQPCO7ZOTW+WPGmr1Q_r5F=8L_XYWKhU1FVb7ON=Q@mail.gmail.com>
References: <CAJZVxRk-xBQPCO7ZOTW+WPGmr1Q_r5F=8L_XYWKhU1FVb7ON=Q@mail.gmail.com>
Date: Tue, 6 May 2014 12:49:24 +0200
Message-ID: <CAH-PCH5-W7o+XgihoO_S+yOcXoT=71t6VZU8-GZ3dOp+T9VP0Q@mail.gmail.com>
To: Aaron Lewis <the.warl0ck.1989@gmail.com>
Cc: PHP Internals <internals@lists.php.net>
Content-Type: multipart/alternative; boundary=001a11c219ea52eae604f8b900aa
Subject: Re: [PHP-DEV] Looking for an example of zend_hash_quick_add() or zend_hash_add()
From: tyra3l@gmail.com (Ferenc Kovacs)

--001a11c219ea52eae604f8b900aa
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

On Mon, May 5, 2014 at 11:29 AM, Aaron Lewis <the.warl0ck.1989@gmail.com>wr=
ote:

> Yes I  can find examples in existing source code,
>
> zend_hash_quick_add(EG(active_symbol_table), key->arKey,
> key->nKeyLength, key->h, &tmp, sizeof(zval*), (void**)&p);
>
> But I only know the HashTable, key, key length parameters, I'm not
> sure what to fill in for the rest
>
> Can anyone give me an example?
>
> --
> Best Regards,
> Aaron Lewis - PGP: 0x13714D33 - http://pgp.mit.edu/
> Finger Print:   9F67 391B B770 8FF6 99DC  D92D 87F6 2602 1371 4D33
>
> --
> PHP Internals - PHP Runtime Development Mailing List
> To unsubscribe, visit: http://www.php.net/unsub.php
>
>
hi,

http://lxr.php.net/xref/PHP_5_6/Zend/zend_hash.h#114
http://lxr.php.net/xref/PHP_5_6/Zend/zend_hash.c#308

#define zend_hash_quick_update(ht, arKey, nKeyLength, h, pData, nDataSize,
pDest)

ht is the HashTable
arKey is the key/index
nKeyLength is the length of the key
h is hash of the key
pData is a pointer to the data
nDataSize is the size of the data eg sizeof(zval *)
pDest is the destination pointer, usually NULL because we don't care about
it most of the times


some docs on the hashtables:
http://www.php.net/manual/en/internals2.variables.tables.php
http://nikic.github.io/2012/03/28/Understanding-PHPs-internal-array-impleme=
ntation.html
http://www.phpinternalsbook.com/hashtables.html (
http://www.phpinternalsbook.com/hashtables/basic_structure.html is a good
start)
(and in Sara's book, Extending and Embedding PHP).

and a simple example:
http://www.phpinternalsbook.com/hashtables/hashtable_api.html#string-keys

For all of the above functions there exists a second quick variant that
> accepts a precomputed hash value after the string length. This allows you
> to compute the hash of a string once and then reuse it across multiple
> calls:
> ulong h; /* hash value */
> /* ... zval init */
> h =3D zend_get_hash_value("foo", sizeof("foo"));
> zend_hash_quick_update(myht, "foo", sizeof("foo"), h, &zv, sizeof(zval *)=
,
> NULL);
> if (zend_hash_quick_find(myht, "foo", sizeof("foo"), h, (void **)
> &zv_dest) =3D=3D SUCCESS) {
>     php_printf("Fetched value at key \"foo\" into zv_dest\n");
> }
> if (zend_hash_quick_del(myht, "foo", sizeof("foo"), h) =3D=3D SUCCESS) {
>     php_printf("Removed value at key \"foo\"\n");
> }
> Using the quick API improves performance as the hash value does not have
> to be recomputed on every call. It should be noted though that this only
> becomes significant if you are accessing the key a lot (e.g. in a loop).
> The quick functions are mostly used in the engine where precomputed hash
> values are available through various caches and optimizations.


ps: somebody please correct me if I'm wrong somewhere!

--=20
Ferenc Kov=C3=A1cs
@Tyr43l - http://tyrael.hu

--001a11c219ea52eae604f8b900aa--