From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48302) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gAWxL-0003ML-Bx for qemu-devel@nongnu.org; Thu, 11 Oct 2018 05:08:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gAWxI-0008Dt-5P for qemu-devel@nongnu.org; Thu, 11 Oct 2018 05:08:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54914) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gAWxH-0008DN-Sl for qemu-devel@nongnu.org; Thu, 11 Oct 2018 05:08:28 -0400 Date: Thu, 11 Oct 2018 10:08:22 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20181011090821.GC2483@work-vm> References: <20181009205652.10605-1-david@redhat.com> <20181009205652.10605-5-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181009205652.10605-5-david@redhat.com> Subject: Re: [Qemu-devel] [PATCH v1 4/7] range: add some more functions List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Hildenbrand Cc: qemu-devel@nongnu.org, "Michael S . Tsirkin" , Igor Mammedov , Markus Armbruster , Michael Roth , David Gibson , Eduardo Habkost * David Hildenbrand (david@redhat.com) wrote: > Add some more functions that will be used in memory-device context. > > range_init(): Init using lower bound and size > range_valid(): Check if there would be an overflow when initializin > range_size(): Extract the size of a range > range_overlaps_range(): Check for overlaps of two ranges > range_contains_range(): Check if one range is contained in the other > range_starts_before_range(): Check if one range starts before another > range_ends_after_range(): Check if one range ends after another > > Signed-off-by: David Hildenbrand > --- > include/qemu/range.h | 80 ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 80 insertions(+) > > diff --git a/include/qemu/range.h b/include/qemu/range.h > index 7e75f4e655..18e8acf22f 100644 > --- a/include/qemu/range.h > +++ b/include/qemu/range.h > @@ -112,6 +112,86 @@ static inline uint64_t range_upb(Range *range) > return range->upb; > } > > +/* > + * Initialize @range to span the interval [@lob,@lob + @size - 1]. > + * @size may be 0. > + */ > +static inline void range_init(Range *range, uint64_t lob, uint64_t size) > +{ > + range->lob = lob; > + range->upb = lob + size - 1; > + range_invariant(range); > +} > + > +/* > + * Check if the interval [@lob,@lob + @size - 1] would be valid or not > + * (result in an overflow). > + */ > +static inline bool range_valid(uint64_t lob, uint64_t size) > +{ > + return lob + size >= lob; > +} That name confused me, I'd expected that to have taken a range and check it for something (like a non-asserting version of the invariant). > +/* > + * Get the size of @range. > + */ > +static inline uint64_t range_size(const Range *range) > +{ > + return range->upb - range->lob + 1; > +} > + > +/* > + * Check if @range1 overlaps with @range2. If one of the ranges is empty, > + * the result is always "false". > + */ > +static inline bool range_overlaps_range(const Range *range1, > + const Range *range2) > +{ > + if (range_is_empty(range1) || range_is_empty(range2)) { > + return false; > + } > + return !(range2->upb < range1->lob || range1->upb < range2->lob); > +} > + > +/* > + * Check if @range1 contains @range2. If one of the ranges is empty, > + * the result is always "false". > + */ > +static inline bool range_contains_range(const Range *range1, > + const Range *range2) > +{ > + if (range_is_empty(range1) || range_is_empty(range2)) { > + return false; > + } > + return range1->lob <= range2->lob && range1->upb >= range2->upb; > +} > + > +/* > + * Check if @range1 starts before @range2. If one of the ranges is empty, > + * the result is alsways "false". > + */ > +static inline bool range_starts_before_range(const Range *range1, > + const Range *range2) > +{ > + if (range_is_empty(range1) || range_is_empty(range2)) { > + return false; > + } > + return range1->lob < range2->lob; > +} > + > +/* > + * Check if @range1 ends after @range2. If one of the ranges is empty, > + * the result is alsways "false". > + */ > +static inline bool range_ends_after_range(const Range *range1, > + const Range *range2) > +{ > + if (range_is_empty(range1) || range_is_empty(range2)) { > + return false; > + } > + return range1->upb > range2->upb; > +} > + > /* > * Extend @range to the smallest interval that includes @extend_by, too. > */ > -- > 2.17.1 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK