Re: I want to release a "git-1.0"

From: Junio C Hamano <junkio@cox.net>
Date: Jun 1, 2005, 23:03 UTC
Message-ID: <7vfyw1isrl.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <Pine.LNX.4.62.0506011304001.21267@qynat.qvtvafvgr.pbz>

>>>>> "DL" == David Lang <david.lang@digitalinsight.com> writes:

Show 6 quoted lines

>> Internally, git-diff-cache -B -C is used which does use the
>> deltify to locate complete rewrites, renames and copies (that's
>> why the script is so slow).  For passing on and assigning blames
>> line by line, parsing "diff --unified=0" output was a lot easier
>> for this script and that was what I did in this quick-and-dirty
>> version.

DL> I was under the impressin that the deltafy stuff was significantly DL> faster then you are suggeting that it is here

I perhaps phrased it poorly.

The slow part is not a single delta operation, but having to run many delta operations between all combinations of rename/copy candidates, which is O(n * m) where n is the number of newly created files (counting "broken" ones created by -B flag) and m is the number of (deleted, modified and unmodified) files in the original tree.