Re: WARNING! Object DB conversion (was Re: [PATCH] write-tree performance problems)

2005-04-20 Thread Ingo Molnar
* Linus Torvalds [EMAIL PROTECTED] wrote: So to convert your old git setup to a new git setup, do the following: [...] did this for two repositories (git and kernel-git), it works as advertised. Ingo - To unsubscribe from this list: send the line unsubscribe git in the body of a

Re: WARNING! Object DB conversion (was Re: [PATCH] write-tree performance problems)

2005-04-20 Thread Jon Seymour
On 4/20/05, Linus Torvalds [EMAIL PROTECTED] wrote: I converted my git archives (kernel and git itself) to do the SHA1 hash _before_ the compression phase. Linus, Am I correct to understand that with this change, all the objects in the database are still being compressed (so no net

Re: WARNING! Object DB conversion (was Re: [PATCH] write-tree performance problems)

2005-04-20 Thread Martin Uecker
On Wed, Apr 20, 2005 at 10:11:10PM +1000, Jon Seymour wrote: On 4/20/05, Linus Torvalds [EMAIL PROTECTED] wrote: I converted my git archives (kernel and git itself) to do the SHA1 hash _before_ the compression phase. Linus, Am I correct to understand that with this change,

Re: WARNING! Object DB conversion (was Re: [PATCH] write-tree performance problems)

2005-04-20 Thread Morten Welinder
On 4/20/05, Martin Uecker [EMAIL PROTECTED] wrote: The storage method of the database of a collection of files in the underlying file system. Because of the random nature of the hashes this leads to a horrible amount of seeking for all operations which walk the logical structure of some tree

Re: WARNING! Object DB conversion (was Re: [PATCH] write-tree performance problems)

2005-04-20 Thread Jon Seymour
The main point is not about trying different compression techniques but that you don't need to compress at all just to calculate the hash of some data. (to know if it is unchanged for example) Ah, ok, I didn't understand that there were extra compresses being performed for that reason.

Re: WARNING! Object DB conversion (was Re: [PATCH] write-tree performance problems)

2005-04-20 Thread David Woodhouse
On Wed, 2005-04-20 at 02:08 -0700, Linus Torvalds wrote: I converted my git archives (kernel and git itself) to do the SHA1 hash _before_ the compression phase. I'm happy to see that -- because I'm going to be asking you to make another change which will also require a simple repository

Re: WARNING! Object DB conversion (was Re: [PATCH] write-tree performance problems)

2005-04-20 Thread Linus Torvalds
On Wed, 20 Apr 2005, Jon Seymour wrote: Am I correct to understand that with this change, all the objects in the database are still being compressed (so no net performance benefit), but by doing the SHA1 calculations before compression you are keeping open the possibility that at some

Re: WARNING! Object DB conversion (was Re: [PATCH] write-tree performance problems)

2005-04-20 Thread Martin Uecker
On Wed, Apr 20, 2005 at 10:30:15AM -0400, C. Scott Ananian wrote: Hi, your code looks pretty cool. thank you! On Wed, 20 Apr 2005, Martin Uecker wrote: The other thing I don't like is the use of a sha1 for a complete file. Switching to some kind of hash tree would allow to introduce

Re: WARNING! Object DB conversion (was Re: [PATCH] write-tree performance problems)

2005-04-20 Thread Martin Uecker
On Wed, Apr 20, 2005 at 11:28:20AM -0400, C. Scott Ananian wrote: Hi, A merkle-tree (which I think you initially pointed me at) makes the hash of the internal nodes be a hash of the chunk's hashes; ie not a straight content hash. This is roughly what my current implementation does, but I

Re: WARNING! Object DB conversion (was Re: [PATCH] write-tree performance problems)

2005-04-20 Thread David Woodhouse
On Wed, 2005-04-20 at 07:59 -0700, Linus Torvalds wrote: external-parent commit-hash external-parent-ID comment for this parent and the nice thing about that is that now that information allows you to add external parents at any point. Why do it like this? First