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From: Nguyen Thai Ngoc Duy <pclouds@gmail.com>
To: David Barr <davidbarr@google.com>
Cc: Junio C Hamano <gitster@pobox.com>, git@vger.kernel.org
Subject: Re: [PATCH 0/9] Prefix-compress on-disk index entries
Date: Wed, 2 May 2012 08:58:50 +0700	[thread overview]
Message-ID: <CACsJy8DZ4t0f_mdDJTUZvz_pBPrPTsEBxHEkYREowWm6D1ikkw@mail.gmail.com> (raw)
In-Reply-To: <CAFfmPPNHkK3SB8cGjfJiVoQoSg2OLL8B5--mwH8HShhJ1WGy2g@mail.gmail.com>

On Fri, Apr 6, 2012 at 3:41 PM, David Barr <davidbarr@google.com> wrote:
> On Thu, Apr 5, 2012 at 4:44 AM, Junio C Hamano <gitster@pobox.com> wrote:
>> Nguyen Thai Ngoc Duy <pclouds@gmail.com> writes:
>>
>>> On Wed, Apr 4, 2012 at 5:53 AM, Junio C Hamano <gitster@pobox.com> wrote:
>>> ...
>>> I wonder what causes user time drop from .29s to .13s here. I think
>>> the main patch should increase computation, even only slightly, not
>>> less.
>>
>> The main patch reduced the amount of the data needs to be sent to the
>> machinery to checksum and write to disk by about 45%, saving both I/O
>> and computation.
>
> I hacked together a quick patch to try predictive coding the other
> fields of the index. I got a further 34% improvement in size over
> this series. Patches to come. I just used the previous cache entry as
> the predictor and reused varint.h together with zigzag encoding[1].
>
> That's a total improvement in size over v2 of 62%.

Have you posted (and I missed) the patches? I'm interested in seeing
what changes you made.

> [1] https://developers.google.com/protocol-buffers/docs/encoding#types
-- 
Duy

  reply	other threads:[~2012-05-02  1:59 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-04-03 22:53 [PATCH 0/9] Prefix-compress on-disk index entries Junio C Hamano
2012-04-03 22:53 ` [PATCH 1/9] varint: make it available outside the context of pack Junio C Hamano
2012-04-03 22:53 ` [PATCH 2/9] cache.h: hide on-disk index details Junio C Hamano
2012-04-03 22:53 ` [PATCH 3/9] read-cache.c: allow unaligned mapping of the index file Junio C Hamano
2012-04-03 22:53 ` [PATCH 4/9] read-cache.c: make create_from_disk() report number of bytes it consumed Junio C Hamano
2012-04-03 22:53 ` [PATCH 5/9] read-cache.c: report the header version we do not understand Junio C Hamano
2012-04-03 22:53 ` [PATCH 6/9] read-cache.c: move code to copy ondisk to incore cache to a helper function Junio C Hamano
2012-04-03 22:53 ` [PATCH 7/9] read-cache.c: move code to copy incore to ondisk " Junio C Hamano
2012-04-03 22:53 ` [PATCH 8/9] read-cache.c: read prefix-compressed names in index on-disk version v4 Junio C Hamano
2012-04-03 22:53 ` [PATCH 9/9] read-cache.c: write index v4 format Junio C Hamano
2012-04-04  1:44 ` [PATCH 0/9] Prefix-compress on-disk index entries David Barr
2012-04-04 15:33   ` Junio C Hamano
2012-04-04 16:57     ` Junio C Hamano
2012-04-04 16:58       ` [PATCH 2/2] update-index: upgrade/downgrade on-disk index version Junio C Hamano
2012-04-04 12:34 ` [PATCH 0/9] Prefix-compress on-disk index entries Nguyen Thai Ngoc Duy
2012-04-04 18:44   ` Junio C Hamano
2012-04-06  8:41     ` David Barr
2012-05-02  1:58       ` Nguyen Thai Ngoc Duy [this message]
2012-05-02  4:26         ` David Barr
2012-04-27 22:58 ` [PATCH 1/2] unpack-trees: preserve the index file version of original Junio C Hamano
2012-04-27 23:02   ` [PATCH 2/2] index-v4: document the entry format Junio C Hamano
2012-04-30 17:20     ` Thomas Rast
2012-05-01  4:00       ` Junio C Hamano
2012-05-01 21:43         ` Thomas Rast
2012-05-02 15:12         ` Shawn Pearce
2012-05-02 17:04           ` Junio C Hamano
2012-05-02 17:13             ` Shawn Pearce

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