From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with archive (Exim 4.43) id 1KAnk2-0003iY-Cq for mharc-grub-devel@gnu.org; Mon, 23 Jun 2008 11:14:02 -0400 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1KAnk1-0003hr-09 for grub-devel@gnu.org; Mon, 23 Jun 2008 11:14:01 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1KAnk0-0003hb-FB for grub-devel@gnu.org; Mon, 23 Jun 2008 11:14:00 -0400 Received: from [199.232.76.173] (port=35599 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1KAnk0-0003hW-9f for grub-devel@gnu.org; Mon, 23 Jun 2008 11:14:00 -0400 Received: from mta-out.inet.fi ([195.156.147.13]:41846 helo=kirsi2.rokki.sonera.fi) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1KAnk0-0004QB-86 for grub-devel@gnu.org; Mon, 23 Jun 2008 11:14:00 -0400 Received: from [127.0.0.1] (88.193.32.97) by kirsi2.rokki.sonera.fi (8.5.014) id 4858893A003537FF for grub-devel@gnu.org; Mon, 23 Jun 2008 18:13:56 +0300 Message-ID: <485FBDBD.1070003@nic.fi> Date: Mon, 23 Jun 2008 18:14:05 +0300 From: =?ISO-8859-1?Q?Vesa_J=E4=E4skel=E4inen?= User-Agent: Thunderbird 2.0.0.14 (Windows/20080421) MIME-Version: 1.0 To: The development of GRUB 2 References: <20080623063655.068e5154@gibibit.com> In-Reply-To: X-Enigmail-Version: 0.95.6 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: Quoted-Printable X-detected-kernel: by monty-python.gnu.org: Linux 2.6 (newer, 3) Subject: Re: DEFLATE compression X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: The development of GRUB 2 List-Id: The development of GRUB 2 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 23 Jun 2008 15:14:01 -0000 Bean wrote: > On Mon, Jun 23, 2008 at 9:36 PM, Colin D Bennett wr= ote: >> How does GRUB support decompressing DEFLATE compressed data? Based on >> my reading of io/gzio.c, it looks like a gzip header is required to >> inflate deflated data. >> >> I am implementing a new font format and will be embedding multiple >> blocks of compressed bitmaps in the font file for a good combination o= f >> space efficient on-disk storage and fast read performance during use. >> A block of character bitmaps will only be read from the file >> and decompressed at run time when a character within that block is >> needed. After that, when any character in the block is needed, it is >> already decompressed in memory for quick access. >> >> I was going to use DEFLATE compression, it looks like I may have to ad= d >> the gzip structure to it, which seems silly since it's just a block of >> data within my file. >> >> Also, is it possible to tell the gzio module to decompress a block of >> data beginning at a specific offset in the file? >=20 > Hi, >=20 > I think it's better to move the deflate decompression function into a > separate module, instead of relying on gzio. I have written similar > deflate function for pnp.c, but it uses callback mode, which call a > function to retrieve the next character. It'd be nice to unify all > deflate decompression in one module, but you need to be careful about > the interface, so that it can be used in both situation (direct and > callback mode). Hi Bean, Can you check the interface as you have previously worked with it? This=20 would free Colin to work on more important aspects. Thanks, Vesa J=E4=E4skel=E4inen