Re: git and mtime

From: Matthias Kestenholz <mk@feinheit.ch>
Date: Nov 20, 2008, 18:36 UTC
Message-ID: <A12D78B0-7CC0-4877-AB91-A547AE1A7EC8@feinheit.ch>
In-Reply-To: <20081120151925.GE6023@codelibre.net>

On 20.11.2008, at 16:19, Roger Leigh wrote:

Show 8 quoted lines

>>
>> Then write a hook for it. You agree that for most users this will be
>> totally insane, and yet you request that it's added in a place where
>> everyone will have to pay the performance/diskspace penalty for it
>> but only a handful will get any benefits. That's patently absurd.
>
> The cost is tiny.  The extra space would be smaller than a single
> SHA1 hash.

No, the cost is huge. The SHA-1 for the tree with _exactly the same contents_ will be different, just because f.e you applied a patch one second earlier than I did, and that's completely insane. Git is purely a content tracker as has been said numerous times on this mailing list, and that is for good reasons. If the tree entries change just because some timestamps are different, the CPU time needed to generate a diff will grow by a big amount of time.

Atempts to add additional information to the basic git objects have failed several times, and yours will probably fail too since there are numerous reasons why you do _not_ want a timestamp in the tree _and_ there are several workarounds for your problem, which at least in my opinion seem much less insane than adding timestamps...

>> Especially since there are such easy workarounds that you can put in
>> place yourself instead.
>