Re: State of NewHash work, future directions, and discussion

["brian m. carlson" <sandals@crustytoothpaste.net>]

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On Mon, Jun 11, 2018 at 08:09:47PM +0200, Duy Nguyen wrote:
> I'm actually thinking that putting the_hash_algo inside struct
> repository is a mistake. We have code that's supposed to work without
> a repo and it shows this does not really make sense to forcefully use
> a partially-valid repo. Keeping the_hash_algo a separate variable
> sounds more elegant.

It can fairly easily be moved out if we want.

> I quickly skimmed through that document. I have two more concerns that
> are less about any specific hash algorithm:
> 
> - how does larger hash size affects git (I guess you covered cpu
> aspect, but what about cache-friendliness, disk usage, memory
> consumption)
> 
> - how does all the function redirection (from abstracting away SHA-1)
> affects git performance. E.g. hashcmp could be optimized and inlined
> by the compiler. Now it still probably can optimize the memcmp(,,20),
> but we stack another indirect function call on top. I guess I might be
> just paranoid and this is not a big deal after all.

I would have to run some numbers on this.  I probably won't get around
to doing that until Friday or Saturday.
-- 
brian m. carlson: Houston, Texas, US
OpenPGP: https://keybase.io/bk2204

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