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From: "Shawn O. Pearce" <spearce@spearce.org>
To: Liu Yubao <yubao.liu@gmail.com>
Cc: Junio C Hamano <gitster@pobox.com>, git list <git@vger.kernel.org>
Subject: Re: [PATCH 5/5] support writing uncompressed loose object
Date: Tue, 2 Dec 2008 08:07:06 -0800	[thread overview]
Message-ID: <20081202160706.GN23984@spearce.org> (raw)
In-Reply-To: <4934975E.2010601@gmail.com>

Liu Yubao <yubao.liu@gmail.com> wrote:
> 
> Signed-off-by: Liu Yubao <yubao.liu@gmail.com>

IMHO, this needs more description in the commit message.

> diff --git a/sha1_file.c b/sha1_file.c
> index 05a9fa3..053b564 100644
> --- a/sha1_file.c
> +++ b/sha1_file.c
> @@ -2328,7 +2328,7 @@ static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename)
>  }
>  
>  static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen,
> -			      void *buf, unsigned long len, time_t mtime)
> +			      void *buf, unsigned long len, time_t mtime, int dont_deflate)

Passing this as an argument is pointless.  It should be a repository
wide configuration option in core, so you can declare it a static and
allow git_config to populate it.  Defaulting to 1 (no compression)
like you do elsewhere in the patch isn't good.

I'm still against this file format change.  The series itself isn't
that bad, and the buffer overflow catch in parse_sha1_header()
may be something worthwhile fixing.  But I'm still not sold that
introducing a new loose object format is worth it.

I'd rather use a binary header encoding like the new-style/in-pack
format rather than the older style text headers.  Its faster to
parse for one thing.

Your changes in the reading code cause a copy of the buffer we
mmap()'d.  That sort of ruins your argument that this change is
worthwhile because concurrent processes on the same host can mmap the
same buffer and save memory.  We're still copying the buffer anyway.
I probably should have commented on that in patch 4/5, but I just
realized it, so I'm saying it here.

-- 
Shawn.

  reply	other threads:[~2008-12-02 16:08 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-12-01  8:00 two questions about the format of loose object Liu Yubao
2008-12-01  8:25 ` Junio C Hamano
2008-12-01  9:28   ` Liu Yubao
2008-12-01 11:32     ` Jakub Narebski
2008-12-02  2:19       ` Liu Yubao
2008-12-01 15:21     ` Shawn O. Pearce
2008-12-02  2:43       ` Liu Yubao
2008-12-02  1:48   ` [PATCH 0/5] support reading and writing uncompressed " Liu Yubao
2008-12-02  1:51   ` [PATCH 1/5] avoid parse_sha1_header() accessing memory out of bound Liu Yubao
2008-12-02 15:42     ` Shawn O. Pearce
2008-12-03  3:49       ` Liu Yubao
2008-12-02  1:53   ` [PATCH 2/5] don't die immediately when convert an invalid type name Liu Yubao
2008-12-02  1:55   ` [PATCH 3/5] optimize parse_sha1_header() a little by detecting object type Liu Yubao
2008-12-02 15:53     ` Shawn O. Pearce
2008-12-03  4:06       ` Liu Yubao
2008-12-02  1:56   ` [PATCH 4/5] support reading uncompressed loose object Liu Yubao
2008-12-02 15:58     ` Shawn O. Pearce
2008-12-03  4:09       ` Liu Yubao
2008-12-02  2:03   ` [PATCH 5/5] support writing " Liu Yubao
2008-12-02 16:07     ` Shawn O. Pearce [this message]
2008-12-03  4:22       ` Liu Yubao
2008-12-02  3:11   ` [PATCH 0/5] support reading and " Liu Yubao
2008-12-01 12:16 ` two questions about the format of " Nick Andrew
2008-12-02  2:26   ` Liu Yubao
2008-12-01 15:32 ` Shawn O. Pearce
2008-12-02  3:05   ` Liu Yubao
2008-12-04  0:54     ` Nicolas Pitre

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