Re: Terrible bad performance for it blame --date=iso -C -C master -- <file>

From: Junio C Hamano <gitster@pobox.com>
Date: May 2, 2017, 00:59 UTC
Message-ID: <xmqqfugof4zb.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <CAJZjrdUt+=oLt0cDcs2+bJMCFR4h8UUSFmZkx6-1menz4haPig@mail.gmail.com>

Samuel Lijin <sxlijin@gmail.com> writes:

Show 9 quoted lines

> On Fri, Mar 31, 2017 at 10:52 AM, Junio C Hamano <gitster@pobox.com> wrote:
>
>> It might not be a bad idea to teach "blame" not to pay attention to
>> any path that is marked as "-diff" (e.g. binary files) when trying
>> to see if remaining contents appeared by borrowing from them.  We do
>> not have that heuristics (yet).
>
> Could you elaborate on this? Do you mean to tell diffcore-rename to
> ignore diff_filespec objects if they're binary?

No and yes ;-). I do not think it is a good idea to unconditionally ignore binary in diffcore-rename.

But when we know that the rename detection is called from inside blame.c, where by definition we would be digging line-oriented contents, there is no point checking if the contents we are looking for came from an existing binary file.