From patchwork Mon Feb 10 18:37:05 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Andreas_F=C3=A4rber?= X-Patchwork-Id: 318938 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 15C1E2C00B8 for ; Tue, 11 Feb 2014 06:44:21 +1100 (EST) Received: from localhost ([::1]:57556 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WCw1w-0001Zt-Ij for incoming@patchwork.ozlabs.org; Mon, 10 Feb 2014 13:56:32 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51944) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WCvjU-0004qt-Sa for qemu-devel@nongnu.org; Mon, 10 Feb 2014 13:37:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WCvjD-0005uY-H8 for qemu-devel@nongnu.org; Mon, 10 Feb 2014 13:37:28 -0500 Received: from cantor2.suse.de ([195.135.220.15]:47145 helo=mx2.suse.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WCvjD-0005pB-Br for qemu-devel@nongnu.org; Mon, 10 Feb 2014 13:37:11 -0500 Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 1FC82ABF6; Mon, 10 Feb 2014 18:37:11 +0000 (UTC) From: =?UTF-8?q?Andreas=20F=C3=A4rber?= To: qemu-devel@nongnu.org Date: Mon, 10 Feb 2014 19:37:05 +0100 Message-Id: <1392057426-31990-49-git-send-email-afaerber@suse.de> X-Mailer: git-send-email 1.8.4.5 In-Reply-To: <1392057426-31990-1-git-send-email-afaerber@suse.de> References: <1392057426-31990-1-git-send-email-afaerber@suse.de> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 195.135.220.15 Cc: Michael Roth , Paolo Bonzini , =?UTF-8?q?Andreas=20F=C3=A4rber?= , Luiz Capitulino Subject: [Qemu-devel] [PULL 48/48] qapi: Refine human printing of sizes X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Paolo Bonzini This fixes several bugs or shortcomings of the previous pretty-printer. In particular: * use PRIu64 instead of casting to long long * the exact value is included too * the correct unit of measure (MiB, GiB, etc.) is used. PiB and EiB are added too. * due to an off-by-one error, 512*2^30 was printed as 0.500MiB rather than 512MiB. floor(log2(val)) is equal to 63 - clz(val), while the code used 64. * The desired specification is %g rather than %f, which always uses three decimals in the current code. However %g would switch to scientific notation when the integer part is >= 1000 (e.g. 1000*2^30). To keep the code simple, switch to the higher power when the integer part is >= 1000; overflow is avoided by using frexp instead of clz. Suggested-by: Eric Blake Reviewed-by: Igor Mammedov Reviewed-by: Eric Blake Signed-off-by: Paolo Bonzini Signed-off-by: Andreas Färber --- qapi/string-output-visitor.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c index 67a8798..fb1d2e8 100644 --- a/qapi/string-output-visitor.c +++ b/qapi/string-output-visitor.c @@ -15,6 +15,7 @@ #include "qapi/visitor-impl.h" #include "qapi/qmp/qerror.h" #include "qemu/host-utils.h" +#include struct StringOutputVisitor { @@ -47,30 +48,30 @@ static void print_type_size(Visitor *v, uint64_t *obj, const char *name, Error **errp) { StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v); - static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T' }; + static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T', 'P', 'E' }; uint64_t div, val; char *out; int i; if (!sov->human) { - out = g_strdup_printf("%llu", (long long) *obj); + out = g_strdup_printf("%"PRIu64, *obj); string_output_set(sov, out); return; } val = *obj; - /* Compute floor(log2(val)). */ - i = 64 - clz64(val); - - /* Find the power of 1024 that we'll display as the units. */ - i /= 10; - if (i >= ARRAY_SIZE(suffixes)) { - i = ARRAY_SIZE(suffixes) - 1; - } + /* The exponent (returned in i) minus one gives us + * floor(log2(val * 1024 / 1000). The correction makes us + * switch to the higher power when the integer part is >= 1000. + */ + frexp(val / (1000.0 / 1024.0), &i); + i = (i - 1) / 10; + assert(i < ARRAY_SIZE(suffixes)); div = 1ULL << (i * 10); - out = g_strdup_printf("%0.03f%c", (double)val/div, suffixes[i]); + out = g_strdup_printf("%"PRIu64" (%0.3g %c%s)", val, + (double)val/div, suffixes[i], i ? "iB" : ""); string_output_set(sov, out); }