Re: [PATCH v2 01/20] pack-revindex: introduce a new API

From: Jeff King <peff@peff.net>
Date: Jan 14, 2021, 19:19 UTC
Message-ID: <YACZLHm4NtrM3POZ@coredump.intra.peff.net>
In-Reply-To: <YAB6DNk4wPBVbGtU@nand.local>

On Thu, Jan 14, 2021 at 12:06:20PM -0500, Taylor Blau wrote:

Show 13 quoted lines

> > > + * This function runs in time O(log N) with the number of objects in the pack.
> >
> > Is it a good idea to commit to such performance characteristics as a
> > promise to callers like this (the comment applies to all three
> > functions)?
> >
> > It depends on how a developer is helped by this comment when
> > deciding whether to use this function, or find other ways, to
> > implement what s/he wants to do.
> 
> I don't mind it. If they all had the same performance characteristics, I
> wouldn't be for it, but since they don't, I think that it's good to
> know. Peff suggested this back in [1].

Yeah, I asked for this. As somebody who has frequently worked on the code which accesses the revindex (mostly bitmap stuff), I found it useful to understand how expensive the operations were. However, I also know what their runtimes are at this point, and it is not like somebody interested cannot look at the implementation. So it may not be that important.

So I do still think it is useful, but if somebody feels strongly against it, I don't mind it being removed.

-Peff