Re: Git commit generation numbers

On Sun, Jul 17, 2011 at 4:39 PM, George Spelvin [off-list ref] wrote:

I'm slapping my forehead like Homer Simpson here.  The fact that computing
the generation number is expensive is why it's worth cacheing.  But the
fact that it *can* be computed is a reason not to clutter the published
commit object format with it.

And I'm slapping *my* forehead.

Nobody has *ever* given a reason why the cache would be better than
just making it explicit.

That's my issue.

Why is that so hard for people to understand? The cache is just EXTRA WORK.

To take your TLB example: it's like having a TLB for a page table that
would be as easy to just create in a way that it's *faster* to look up
in the actual data structure than it would be to look up in the cache.

Or to take your disk cache example: wouldn't you say that a disk cache
is a F&*&ING BAD IDEA if it is slower than the disk it caches?

Seriously.

                    Linus