Re: [GSoC][RFC][PATCH 2/2] STRBUF_INIT_CONST: Adapting strbuf_* functions

From: Robear Selwans <rwagih.rw@gmail.com>
Date: Feb 19, 2020, 01:43 UTC
Message-ID: <CALH1-Xr3HVZzDn2-9EvmdiBWmxWQ-zfExM2LNJyR1wR+dgxRSQ@mail.gmail.com>
In-Reply-To: <xmqq36b7k4i6.fsf@gitster-ct.c.googlers.com>

On Tue, Feb 18, 2020 at 10:46 PM Junio C Hamano <gitster@pobox.com> wrote:

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> Abhishek Kumar <abhishekkumar8222@gmail.com> writes:
> >> STRBUF_INIT_CONST: a new way to initialize strbuf
> > Use imperative mood and be more specific in the commit title -
> > `strbuf: Teach strbuf to initialize immutable strings`
> s/T/t/;

I don't get what you mean by that.

Show 6 quoted lines

> Also, isn't "if (sb->alloc < sb->len)" too loose a check for the new
> feature?  AFAICS in 1/2, a strbuf that is still borrowing a const
> string always has sb->alloc==0.  Other instances of strbuf that
> happens to satisify the above condition, e.g. (sb->len == 5 &&
> sb->alloc == 1), is an error.  If we are to check the condition
> about sb->len, shouldn't we diagnose such a case as an error, no?

AFAIK after reading the documentation for `strbuf`, there is no other case where `sb->len > sb->alloc` as `alloc` needs to always be more than `len`. I'd like to be corrected if mistaken, though.

> As Peff, I am a bit hesitant about leaving a strbuf that hasn't been
> made mutable around, though.

Yeah, I started to get that when I read Peff's reply. I think I'll go with the approach that Peff suggested, where the constant string is copied to a stack array and so is made mutable to a degree. Since this is a different way, I guess I'll make that from scratch instead of editing the existing one.