Re: RFC: Flat directory for notes, or fan-out? Both!

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi,

On Wed, 11 Feb 2009, Junio C Hamano wrote:

> Johannes Schindelin <Johannes.Schindelin@xxxxxx> writes:
> 
> > Even the merging should not pose any problem at all; we need a custom 
> > merge driver anyway, and there is no reason whatsoever why we should 
> > not just teach the merge driver to remove the slashes before comparing 
> > the filie names.
> 
> Once you start talking about "remove the slashes", you are assuming that 
> the custom merge algorithm must look at *all the paths* in the two trees 
> being merged, and it is a sign that your thinking is so trapped in the 
> inefficient way the current merge-recursive and unpack-trees based merge 
> works, and cannot think about the possibility that there could be more 
> efficient way to do merges.  Not very good.
> 
> If you have a fixed boundary and if most subtrees are the same between 
> two notes during a merge, we can do the same optimization as we do for 
> two input "diff-tree" codepath.  If the top of a subtree matches, we do 
> not even have to look at their subtree.  But that is true only if you do 
> not remove the slashes and allow a random hierarchy.

Well, I think in the case of notes, we have to optimize for random access 
of dozens of blobs rather than for merging.  I was well aware that the 
merging is more expensive when the hierarchy is not defined a priori.

Ciao,
Dscho

--
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Kernel Development]     [Gcc Help]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [V4L]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]     [Fedora Users]

  Powered by Linux