Re: [PATCH] hex.c: reduce memory footprint of sha1_to_hex static buffers

From: Stefan Beller <sbeller@google.com>
Date: Feb 13, 2015, 21:56 UTC
Message-ID: <CAGZ79kaEun-mEQPg7cmPV7RJR8A+BxSsSpeAQgcsuJn8L4TGEg@mail.gmail.com>
In-Reply-To: <xmqq7fvlmqu8.fsf@gitster.dls.corp.google.com>

On Fri, Feb 13, 2015 at 1:41 PM, Junio C Hamano <gitster@pobox.com> wrote:

Show 14 quoted lines

> Stefan Beller <sbeller@google.com> writes:
>
>> 41 bytes is the exact number of bytes needed for having the returned
>> hex string represented. 50 seems to be an arbitrary number, such
>> that there are no benefits from alignment to certain address boundaries.
>
> Yes, with s/seems to be/is/;
>
> This comes from e83c5163 (Initial revision of "git", the information
> manager from hell, 2005-04-07), and when dcb3450f (sha1_to_hex()
> usage cleanup, 2006-05-03) introduced the "4 recycled buffers" on
> top, the underlying array was left at 50 bytes long.
>
> You can now have "I fixed Linus's bug" badge ;-)

I don't think it's a bug, it's just wasting memory?

As I could not find any documentation on the magical 50 in the early days, I cc'd Linus in case there is something I did not think of yet.