Re: [PATCH 1/4] diff.h: extend "flags" field to 64 bits because we're out of bits

From: Duy Nguyen <pclouds@gmail.com>
Date: Jun 7, 2016, 00:40 UTC
Message-ID: <CACsJy8AVzWBsDhzj+UJo9AbSi0f=jrAyrLZ9sU=VBP3woFXr0A@mail.gmail.com>
In-Reply-To: <xmqqfusqw17r.fsf@gitster.mtv.corp.google.com>

On Tue, Jun 7, 2016 at 2:45 AM, Junio C Hamano <gitster@pobox.com> wrote:

Show 11 quoted lines

> Nguyễn Thái Ngọc Duy  <pclouds@gmail.com> writes:
>
>> Current flags field is 32-bits, all used except one bit and we need one
>> more bit is needed for to toggle i-t-a behavior. The 9th bit could be
>> reused for this, but we could just extend it to 64 bits now to give room
>> for more future flags.
>
> Isn't it a better option to add new things as separate words (or a
> separate bit:1 field)?  Is this 32nd thing envisioned to be added
> going to be used everywhere like the existing flag bits, or can it
> be handled like "use_color", "break_opt", "show_rename_progress"?

It could probably live as a separate bitfield, or an int. What scares me is "flags" sometimes is backed up then restored, but it's probably ok. But we need to extend this "flags" eventually, don't we? I don't think people will stop adding new DIFF_OPT_ flags.

-- 
Duy