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 X-Spam-Level: X-Spam-Status: No, score=-5.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 697F2C433DB for ; Fri, 5 Feb 2021 14:37:57 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CF90D650DA for ; Fri, 5 Feb 2021 14:37:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CF90D650DA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:42466 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l82F9-0005oz-Of for qemu-devel@archiver.kernel.org; Fri, 05 Feb 2021 09:37:55 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:40694) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l82Ds-0004cw-5P for qemu-devel@nongnu.org; Fri, 05 Feb 2021 09:36:36 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:29214) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1l82Dq-0007U4-3y for qemu-devel@nongnu.org; Fri, 05 Feb 2021 09:36:35 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612535793; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/vizd6mekfrRgm5TBdMWUobQtTY5rEIc5CyHj+U1/xQ=; b=HjNvuBpcHdPQTBIhdoq+VEHmF8HsQdC5/BI8EMe2Gvi5CzZRf55Khj3CELzy9Nr1E6MBDc Dt9RWGqqK2xQ6IbRkTIq+3nEPsfmEEqqLLwDmDSx+oTCwJPKOmTv9dBN1JKzeTwCtyXadt QkGGuJFpewA7Xj9ho1rpxldTNWF16fc= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-468-RWEtTU4gMs6UhGkdFSHvVQ-1; Fri, 05 Feb 2021 09:36:27 -0500 X-MC-Unique: RWEtTU4gMs6UhGkdFSHvVQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 71822100CCC0; Fri, 5 Feb 2021 14:36:25 +0000 (UTC) Received: from redhat.com (ovpn-114-212.ams2.redhat.com [10.36.114.212]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4227360937; Fri, 5 Feb 2021 14:36:23 +0000 (UTC) Date: Fri, 5 Feb 2021 14:36:20 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Eric Blake Subject: Re: [PATCH 1/3] utils: Improve qemu_strtosz() to have 64 bits of precision Message-ID: <20210205143620.GQ908621@redhat.com> References: <20210204190708.1306296-1-eblake@redhat.com> <20210204190708.1306296-2-eblake@redhat.com> <20210205110206.GD908621@redhat.com> <1e2a3fbf-b501-403e-d472-3b114c6b18ea@redhat.com> MIME-Version: 1.0 In-Reply-To: <1e2a3fbf-b501-403e-d472-3b114c6b18ea@redhat.com> User-Agent: Mutt/1.14.6 (2020-07-11) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=63.128.21.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.352, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Kevin Wolf , vsementsov@virtuozzo.com, qemu-block@nongnu.org, rjones@redhat.com, tao3.xu@intel.com, armbru@redhat.com, qemu-devel@nongnu.org, Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, Feb 05, 2021 at 08:27:14AM -0600, Eric Blake wrote: > On 2/5/21 5:02 AM, Daniel P. Berrangé wrote: > > >> /* > >> - * Convert string to bytes, allowing either B/b for bytes, K/k for KB, > >> - * M/m for MB, G/g for GB or T/t for TB. End pointer will be returned > >> - * in *end, if not NULL. Return -ERANGE on overflow, and -EINVAL on > >> - * other error. > >> + * Convert size string to bytes. > >> + * > >> + * Allow either B/b for bytes, K/k for KB, M/m for MB, G/g for GB or > >> + * T/t for TB, with scaling based on @unit, and with @default_suffix > >> + * implied if no explicit suffix was given. > >> + * > >> + * The end pointer will be returned in *end, if not NULL. If there is > >> + * no fraction, the input can be decimal or hexadecimal; if there is a > >> + * fraction, then the input must be decimal and there must be a suffix > >> + * (possibly by @default_suffix) larger than Byte, and the fractional > >> + * portion may suffer from precision loss or rounding. The input must > >> + * be positive. > > > > Even though the test suite gives some illustrations, I think we should > > document here the patterns we're intending to support. IIUC, we aim for > > > > [quote] > > The size parsing supports the following syntaxes > > > > - 12345 - decimal, bytes > > - 12345{bBkKmMgGtT} - decimal, scaled bytes > > Yes. Actually 12345{bBkKmMgGtTpPeE}, as long as it doesn't overflow 16E. > > > - 12345.678 - fractional decimal, bytes > > No - this was already rejected prior to my patch, and my patch keeps it > as rejected (that's the whole mul_required bool, which checks whether > mul > 1). Oh yes, of course. > > - 12345.678{bBkKmMgGtT} - fractional decimal, scaled bytes > > Close; we reject bB in this situation for the same reason that we reject > fractional decimal without suffix. Also, patch 3/3 was questioning > whether the fractional portion must be exact or is permitted to round Yep, rejecting bB makes sense. > > > - 0x7FEE - hex, bytes > > Yes, and with the additional note that 'E' and 'B' are treated as hex > digits, not scale suffixes, in this form. > > > > > The following are intentionally not supported > > > > - octal > > Never has worked. > > > - fractional hex > > worked by accident, dropping it in this patch is not deemed worth a > deprecation period. > > > - floating point exponents > > worked by accident, dropping it in this patch is not deemed worth a > deprecation period. > > > [/quote] > > and with one more form: > > patch 2/3 > - 0x123abc{kKmMgGtTpP} - hex, scaled bytes, with limited set of working > suffixes, and slated for future removal (this one is barely plausible > enough that we need the deprecation period to see who uses it) Ok Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|