From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Mon, 02 Jun 2008 18:22:01 GMT
Subject: Re: [PATCH] Adding a cache of commit to patch-id pairs to speed up git-cherry
Message-ID: <alpine.DEB.1.00.0806021918590.13507@racer.site.net>
In-Reply-To: <7f9d599f0806021023r64affb36ne491792a962d455c@mail.gmail.com>

Hi,

On Mon, 2 Jun 2008, Geoffrey Irving wrote:

> On Mon, Jun 2, 2008 at 7:50 AM, Geoffrey Irving <irving@naml.us> wrote:
>
> I'll switch to mmapping.
> 
> The git_mmap function in compat/mmap.c dies if NO_MMAP is defined and 
> the map isn't MAP_PRIVATE.  If I want to write an entry, will the memory 
> be automatically updated if I write directly to the file descriptor (I 
> haven't used mmap before)?

I think that you should only mmap() with MAP_PRIVATE, because you can 
corrupt the data easily when a write failure is not handled properly.

So I'd suggest mmap() for reading, and writing to a locked file (I think 
you did that already).

Ciao,
Dscho