From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Leno Hou <lenohou@gmail.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1]] lib/btree.c: optimise the code by previously getpos function
Date: Fri, 28 Apr 2017 19:40:34 +0300 [thread overview]
Message-ID: <CAHp75VfX0u11mRieRAH=P_6xzbL2cKjbhKNopv-ia70duH1Cfg@mail.gmail.com> (raw)
In-Reply-To: <1491893636-60759-1-git-send-email-lenohou@gmail.com>
On Tue, Apr 11, 2017 at 9:53 AM, Leno Hou <lenohou@gmail.com> wrote:
> This patch optimized the code by previously getpos function call.
> Therefore, It's takes the convenience to understand logic of code.
Besides what Christoph told you (I agree with him, writing test suites
/ modules is quite good exercise for newbies) my 2 cents for below
code that you may consider in the future as a technique of cleaning
up,
> +static int getpos(struct btree_geo *geo, unsigned long *node,
> + unsigned long *key)
> +{
> + int i;
unsigned int i;
> +
> + for (i = 0; i < geo->no_pairs; i++) {
> + if (keycmp(geo, node, i, key) <= 0)
> + break;
Here you return directly
return i;
> + }
> + return i;
And here is the best to return negative error code instead, like
return -ENOENT;
> +}
> for ( ; height > 1; height--) {
> - for (i = 0; i < geo->no_pairs; i++)
> - if (keycmp(geo, node, i, key) <= 0)
> - break;
> + i = getpos(geo, node, key);
> if (i == geo->no_pairs)
> return NULL;
Taking above into consideration you may do
i = getpos(geo, node, key);
if (i < 0)
return NULL;
Rationale behind that:
1) getpos() return value may be directly used whenever we need return
code to return;
2) you hide implementation details in your helper function
(geo->no_pairs dereference).
Though here both of them kinda minors you may use such technique in
the future for more complex code.
--
With Best Regards,
Andy Shevchenko
prev parent reply other threads:[~2017-04-28 16:40 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-11 6:53 [PATCH v1]] lib/btree.c: optimise the code by previously getpos function Leno Hou
2017-04-11 16:20 ` Christoph Hellwig
[not found] ` <CAGQVrL_2EanSVKkMEP_fBaeWSwu=tZYSq79nzOy-wXQ9m1WOuQ@mail.gmail.com>
2017-04-12 17:32 ` Christoph Hellwig
2017-04-19 14:48 ` Leno Hou
2017-04-28 16:40 ` Andy Shevchenko [this message]
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