From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Benjamin Subject: Re: inline vector container Date: Wed, 3 Feb 2016 16:24:51 -0500 (EST) Message-ID: <901964622.31580193.1454534691235.JavaMail.zimbra@redhat.com> References: <1382260306.31547015.1454533040094.JavaMail.zimbra@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mx3-phx2.redhat.com ([209.132.183.24]:52773 "EHLO mx3-phx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755763AbcBCVYz convert rfc822-to-8bit (ORCPT ); Wed, 3 Feb 2016 16:24:55 -0500 In-Reply-To: Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Milosz Tanski Cc: Sage Weil , Allen Samuels , ceph-devel , cbodley@redhat.com Yeah, that looks a lot more reasonable if we must split it out, though = I would prefer boost. Matt ----- Original Message ----- > From: "Milosz Tanski" > To: "Matt Benjamin" > Cc: "Sage Weil" , "Allen Samuels" , "ceph-devel" > , cbodley@redhat.com > Sent: Wednesday, February 3, 2016 4:21:12 PM > Subject: Re: inline vector container >=20 > On Wed, Feb 3, 2016 at 3:57 PM, Matt Benjamin = wrote: > > > > Hi, > > > > I think we should go with small_vector for this role, yes. I found= two > > issues. First, there are critical defects in small_vector prior to= boost > > 1.6.0. Second, though it is header-only, the coupling with related > > version-specific boost types (container, allocator, respective deta= il > > types, and platform-specific selectors...) seems to make pulling it= in > > separately pretty unrealistic as an option. I looked at the cost o= f > > pulling in and selectively compiling (libs) an entire boost 1.6, an= d that > > went a lot easier (added less than a minute to my build time). > > > > Matt > > > > ----- Original Message ----- > > > From: "Sage Weil" > > > To: "Allen Samuels" > > > Cc: ceph-devel@vger.kernel.org, mbenjami@redhat.com, cbodley@redh= at.com > > > Sent: Wednesday, February 3, 2016 3:04:57 PM > > > Subject: Re: inline vector container > > > > > > On Wed, 3 Feb 2016, Allen Samuels wrote: > > > > One thing that the code base needs is a simple vector container= that is > > > > optimized for a small number of elements, i.e., for small eleme= nt > > > > counts we > > > > avoid the malloc/free overhead. But fully supports being resize= d into > > > > larger > > > > containers that are unbounded. Of course it will need to follow= all of > > > > the > > > > proper object copy/move semantics so that things like unique_pt= r, etc > > > > work > > > > correctly. > > > > > > > > I heard rumors that there was one available in the boost world,= but I > > > > can=E2=80=99t > > > > seem to find it. Do you know about one being available? > > > > > > http://www.boost.org/doc/libs/1_60_0/doc/html/boost/container/sma= ll_vector.html >=20 >=20 > The fb / folly code also has a small vector: > https://github.com/facebook/folly/blob/master/folly/small_vector.h > that used a C++11 move semantics whenever possible. Compared other > parts of folly this has pretty small dependencies on folly and those > can prob be ripped out. >=20 > > > > > > > > > > > I=E2=80=99ve been prototyping one myself, just to get re-famili= ar with all of > > > > the > > > > C++11 move sementics, and trivial constructors, etc. > > > > > > > > The code is pretty complete, but the testing gets rather involv= ed. > > > > There=E2=80=99s > > > > no reason to contain this if it=E2=80=99s available elsewhere. = But if it isn=E2=80=99t > > > > I > > > > plan on continuing this=E2=80=A6 > > > > > > I think Casey had prototyped something similar using a custom all= ocator, > > > too, but I didn't actually look at the result. And Matt talked a= bout > > > just > > > pulling the boost one in-tree until we get updated boost in the s= upported > > > distros, but I forget if he ran into problems there or not... > > > > > > sage > > > > -- > > -- > > Matt Benjamin > > Red Hat, Inc. > > 315 West Huron Street, Suite 140A > > Ann Arbor, Michigan 48103 > > > > http://www.redhat.com/en/technologies/storage > > > > tel. 734-707-0660 > > fax. 734-769-8938 > > cel. 734-216-5309 > > -- > > To unsubscribe from this list: send the line "unsubscribe ceph-deve= l" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html >=20 >=20 >=20 >=20 > -- > Milosz Tanski > CTO > 16 East 34th Street, 15th floor > New York, NY 10016 >=20 > p: 646-253-9055 > e: milosz@adfin.com >=20 --=20 --=20 Matt Benjamin Red Hat, Inc. 315 West Huron Street, Suite 140A Ann Arbor, Michigan 48103 http://www.redhat.com/en/technologies/storage tel. 734-707-0660 fax. 734-769-8938 cel. 734-216-5309 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html