From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6F755EB64D9 for ; Mon, 10 Jul 2023 04:55:18 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4QzsBY03lnz3bpN for ; Mon, 10 Jul 2023 14:55:17 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.alibaba.com (client-ip=115.124.30.119; helo=out30-119.freemail.mail.aliyun.com; envelope-from=hsiangkao@linux.alibaba.com; receiver=lists.ozlabs.org) Received: from out30-119.freemail.mail.aliyun.com (out30-119.freemail.mail.aliyun.com [115.124.30.119]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4QzsBR3TWVz301Q for ; Mon, 10 Jul 2023 14:55:11 +1000 (AEST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R191e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046059;MF=hsiangkao@linux.alibaba.com;NM=1;PH=DS;RN=2;SR=0;TI=SMTPD_---0VmxtpcR_1688964906; Received: from 30.97.48.247(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0VmxtpcR_1688964906) by smtp.aliyun-inc.com; Mon, 10 Jul 2023 12:55:07 +0800 Message-ID: Date: Mon, 10 Jul 2023 12:55:04 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.12.0 Subject: Re: [PATCH 2/4] erofs-utils: add a built-in DEFLATE compressor From: Gao Xiang To: Eric Biggers References: <20230709182511.96954-1-hsiangkao@linux.alibaba.com> <20230709182511.96954-3-hsiangkao@linux.alibaba.com> <20230710023300.GA185469@sol.localdomain> <52875e72-4871-7615-3f20-f02cd9548898@linux.alibaba.com> <20230710041638.GA21080@sol.localdomain> <607b9642-7bdc-e4f6-f8cc-0096e3c99341@linux.alibaba.com> In-Reply-To: <607b9642-7bdc-e4f6-f8cc-0096e3c99341@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-BeenThere: linux-erofs@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development of Linux EROFS file system List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-erofs@lists.ozlabs.org Errors-To: linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Sender: "Linux-erofs" (forgot to respond something...) On 2023/7/10 12:51, Gao Xiang wrote: > > ... >> >>> >>> I think we could use this way first for the new Zstd support (if they don't have >>> bandwidth to add a offical fixed-sized output approach), but considering deflate >>> algorithm is quite easy for me to understand so at least I could have a simple >>> built-in one to avoid external dependency (mainly considering zlib since it's >>> quite outdated).  Since EROFS is actually offline compression so the compressed >>> data correctness can always be checked in advance before image release. >> >> Writing an optimized compressor, especially one that implements high compression >> levels, is very hard.  Are you sure it's something you want to implement and >> maintain in erofs-utils? Nope, as I said earlier, I'd like to write a simple one to replace zlib functionality (kite_deflate already does), and I hope more popular encoders could have offical modes for EROFS in the long term. That is something that I wish to the opensource communities... Thanks, Gao Xiang