From: Johannes Schindelin <Johannes.Schindelin@gmx.de>
To: Andreas Ericsson <ae@op5.se>
Cc: Jakub Narebski <jnareb@gmail.com>,
"Shawn O. Pearce" <spearce@spearce.org>,
Nicolas Pitre <nico@cam.org>, Junio C Hamano <gitster@pobox.com>,
git@vger.kernel.org, Stephan Hennig <mailing_list@arcor.de>
Subject: Re: [PATCH 0/4] Honor core.deltaBaseCacheLimit during index-pack
Date: Mon, 14 Jul 2008 13:25:54 +0100 (BST) [thread overview]
Message-ID: <alpine.DEB.1.00.0807141322140.8950@racer> (raw)
In-Reply-To: <487B439F.8040902@op5.se>
Hi,
On Mon, 14 Jul 2008, Andreas Ericsson wrote:
> Sorry for being clueless here, but why does the older versions need
> to be kept in-memory anyway? Aren't we applying the delta each time
> we find one, repeatedly creating a new base-object in-memory for
> each delta? If we aren't doing that, why do we need more than just
> a small amount of memory just for keeping the delta?
Think of a delta chain of 49 delta objects, 1 base object. Now
reconstruct all of the objects.
If you do it one by one, not storing the intermediate results, you end up
applying 1 delta for the first, 2 for the second (first the first, then
the second), and so on, in total 1 + 2 + 3 + ... + 49 = 49 * 50 / 2 = 1225
times.
Compare that to the 49 times when reusing the intermediate results.
Ciao,
Dscho
next prev parent reply other threads:[~2008-07-14 12:26 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-10 14:40 git pull is slow Stephan Hennig
2008-07-10 15:13 ` Martin Langhoff
2008-07-10 15:28 ` Petr Baudis
2008-07-10 15:30 ` Johannes Sixt
2008-07-10 15:45 ` Stephan Hennig
2008-07-10 15:50 ` Petr Baudis
2008-07-10 17:44 ` Stephan Hennig
2008-07-11 12:25 ` Stephan Hennig
2008-07-11 13:34 ` Andreas Ericsson
2008-07-11 14:04 ` Johannes Schindelin
2008-07-12 12:32 ` Stephan Hennig
2008-07-12 17:05 ` Johannes Schindelin
2008-07-13 1:15 ` Shawn O. Pearce
2008-07-13 13:59 ` Johannes Schindelin
2008-07-13 22:11 ` Shawn O. Pearce
2008-07-14 2:07 ` [PATCH 0/4] Honor core.deltaBaseCacheLimit during index-pack Shawn O. Pearce
2008-07-14 2:27 ` Nicolas Pitre
2008-07-14 3:12 ` Shawn O. Pearce
2008-07-14 11:44 ` Johannes Schindelin
2008-07-14 11:54 ` Jakub Narebski
2008-07-14 12:10 ` Johannes Schindelin
2008-07-14 12:16 ` Andreas Ericsson
2008-07-14 12:25 ` Johannes Schindelin [this message]
2008-07-14 12:51 ` Andreas Ericsson
2008-07-14 12:58 ` Johannes Schindelin
2008-07-15 2:21 ` Nicolas Pitre
2008-07-15 2:47 ` Shawn O. Pearce
2008-07-15 3:06 ` Nicolas Pitre
2008-07-17 16:06 ` Stephan Hennig
2008-07-17 16:25 ` Nicolas Pitre
2008-07-17 21:35 ` Shawn O. Pearce
2008-07-17 22:02 ` [RFC PATCH] index-pack: Issue a warning if deltaBaseCacheLimit is too small Shawn O. Pearce
2008-07-17 23:45 ` Nicolas Pitre
2008-07-15 4:19 ` [PATCH 0/4] Honor core.deltaBaseCacheLimit during index-pack Shawn O. Pearce
2008-07-14 2:07 ` [PATCH 1/4] index-pack: Refactor base arguments of resolve_delta into a struct Shawn O. Pearce
2008-07-15 2:40 ` Nicolas Pitre
2008-07-14 2:07 ` [PATCH 2/4] index-pack: Chain the struct base_data on the stack for traversal Shawn O. Pearce
2008-07-15 2:48 ` Nicolas Pitre
2008-07-14 2:07 ` [PATCH 3/4] index-pack: Track the object_entry that creates each base_data Shawn O. Pearce
2008-07-14 10:15 ` Johannes Schindelin
2008-07-15 2:50 ` Nicolas Pitre
2008-07-15 3:20 ` Shawn O. Pearce
2008-07-15 3:42 ` Nicolas Pitre
2008-07-14 2:07 ` [PATCH 4/4] index-pack: Honor core.deltaBaseCacheLimit when resolving deltas Shawn O. Pearce
2008-07-15 3:05 ` Nicolas Pitre
2008-07-15 3:18 ` Shawn O. Pearce
2008-07-15 4:45 ` [PATCH v2] " Shawn O. Pearce
2008-07-15 5:05 ` Nicolas Pitre
2008-07-15 18:48 ` Junio C Hamano
2008-07-13 9:01 ` git pull is slow Stephan Hennig
2008-07-11 12:55 ` Stephan Hennig
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