From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35308) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d8nms-0000Fm-3O for qemu-devel@nongnu.org; Thu, 11 May 2017 09:05:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d8nml-0007aX-UG for qemu-devel@nongnu.org; Thu, 11 May 2017 09:05:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45062) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d8nml-0007ZK-KY for qemu-devel@nongnu.org; Thu, 11 May 2017 09:05:39 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 65DD537E65 for ; Thu, 11 May 2017 13:05:37 +0000 (UTC) Date: Thu, 11 May 2017 14:05:26 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20170511130525.GG2078@work-vm> References: <1494505358-15287-1-git-send-email-peterx@redhat.com> <1494505358-15287-3-git-send-email-peterx@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1494505358-15287-3-git-send-email-peterx@redhat.com> Subject: Re: [Qemu-devel] [PATCH v7 2/4] utils: provide size_to_str() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Xu Cc: qemu-devel@nongnu.org, Paolo Bonzini , Markus Armbruster * Peter Xu (peterx@redhat.com) wrote: > Moving the algorithm from print_type_size() into size_to_str() so that > other component can also leverage it. With that, refactor > print_type_size(). > > Reviewed-by: Markus Armbruster > Signed-off-by: Peter Xu > --- > include/qemu-common.h | 1 + > qapi/string-output-visitor.c | 22 ++++++---------------- > util/cutils.c | 26 ++++++++++++++++++++++++++ > 3 files changed, 33 insertions(+), 16 deletions(-) > > diff --git a/include/qemu-common.h b/include/qemu-common.h > index d218821..d7d0448 100644 > --- a/include/qemu-common.h > +++ b/include/qemu-common.h > @@ -145,6 +145,7 @@ void qemu_hexdump(const char *buf, FILE *fp, const char *prefix, size_t size); > int parse_debug_env(const char *name, int max, int initial); > > const char *qemu_ether_ntoa(const MACAddr *mac); > +char *size_to_str(double val); > void page_size_init(void); > > /* returns non-zero if dump is in progress, otherwise zero is > diff --git a/qapi/string-output-visitor.c b/qapi/string-output-visitor.c > index 94ac821..53c2175 100644 > --- a/qapi/string-output-visitor.c > +++ b/qapi/string-output-visitor.c > @@ -211,10 +211,8 @@ static void print_type_size(Visitor *v, const char *name, uint64_t *obj, > Error **errp) > { > StringOutputVisitor *sov = to_sov(v); > - static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T', 'P', 'E' }; > - uint64_t div, val; > - char *out; > - int i; > + uint64_t val; > + char *out, *psize; > > if (!sov->human) { > out = g_strdup_printf("%"PRIu64, *obj); > @@ -223,19 +221,11 @@ static void print_type_size(Visitor *v, const char *name, uint64_t *obj, > } > > val = *obj; > - > - /* 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("%"PRIu64" (%0.3g %c%s)", val, > - (double)val/div, suffixes[i], i ? "iB" : ""); > + psize = size_to_str(val); > + out = g_strdup_printf("%"PRIu64" (%s)", val, psize); > string_output_set(sov, out); > + > + g_free(psize); > } > > static void print_type_bool(Visitor *v, const char *name, bool *obj, > diff --git a/util/cutils.c b/util/cutils.c > index 50ad179..fa5ddec 100644 > --- a/util/cutils.c > +++ b/util/cutils.c > @@ -619,3 +619,29 @@ const char *qemu_ether_ntoa(const MACAddr *mac) > > return ret; > } > + > +/* > + * Return human readable string for size @val. > + * @val must be between (-1000Eib, 1000EiB), exclusively. > + * Use IEC binary units like KiB, MiB, and so forth. > + * Caller is responsible for passing it to g_free(). > + */ > +char *size_to_str(double val) > +{ > + static const char *suffixes[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei" }; > + unsigned long div; > + int i; > + > + /* > + * 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. > + * (see e41b509d68afb1f for more info) > + */ > + frexp(val / (1000.0 / 1024.0), &i); > + i = (i - 1) / 10; > + assert(i < ARRAY_SIZE(suffixes)); Because your code takes a double, where as Paolo's only takes uint's, I think you have to be careful to check that i >= 0 as well, for example, what would happen if someone did size_to_str(1.0/100.0) ? Dave > + div = 1ULL << (i * 10); > + > + return g_strdup_printf("%0.3g %sB", val / div, suffixes[i]); > +} > -- > 2.7.4 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK