From: Junio C Hamano <gitster@pobox.com>
Date: Thu, 02 May 2013 15:46:08 GMT
Subject: Re: [PATCH] lookup_object: prioritize recently found objects
Message-ID: <7vzjwd1j27.fsf@alter.siamese.dyndns.org>
In-Reply-To: <5182101D.4050807@viscovery.net>

Johannes Sixt <j.sixt@viscovery.net> writes:

> BTW, do you notice that the function is now modifying an object (the hash
> table) even though this is rather unexpected from a "lookup" function?

At the philosophical level, "lookup" ought to be operating on a
"const" table.  But at the implementation level, the table does not
have to be "const" in the sense the implemenation language and data
structure defines.

I think this patch is a good example of that.

I am kind of surprised that Jeff's attempt to do a full LRU made
things worse, though.  The only additional code compared to swap is
a single memmove(): are we colliding too often (having to move a
lot)?