Re: [PATCH 0/3] xdiff: speedup histogram diff

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Nov 18, 2021, 15:40 UTC
Message-ID: <nycvar.QRO.7.76.6.2111181636580.11028@tvgsbejvaqbjf.bet>
In-Reply-To: <pull.1079.git.1637148025.gitgitgadget@gmail.com>

Hi Phillip,

On Wed, 17 Nov 2021, Phillip Wood via GitGitGadget wrote:

Show 5 quoted lines

> Histogram is the only diff algorithm not to call xdl_classify_record().
> Calling xdl_classify_record() means that it is not necessary to use
> xdl_recmatch() when comparing lines, all that is necessary is to compare the
> hash values. This gives a 7% reduction in the runtime of "git log --patch"
> when using the histogram diff algorithm.

Thanks for this! I had a look over the patches (and refreshed my memory of what `xdl_classify_record()` does), and they look good.

Having said that, I would love to increase my confidence by backing up the patches with a sort of stress test. Do we have anything like that? I guess not, a `git grep histogram t/` did not really turn up anything promising, p4000 does not even validate the output...

Thanks, Dscho