From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pete Zaitcev Subject: Re: Design challenges in chunkd self-checking Date: Tue, 5 Jan 2010 14:39:35 -0700 Message-ID: <20100105143935.69adb51e@redhat.com> References: <20091222144111.789a5b91@redhat.com> <4B314BAE.4010805@garzik.org> <20091222184014.22c5d1c5@redhat.com> <4B319030.9070906@garzik.org> <20100105134702.1e72ced2@redhat.com> <4B43A902.5070105@garzik.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4B43A902.5070105@garzik.org> Sender: hail-devel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Jeff Garzik Cc: Project Hail List On Tue, 05 Jan 2010 16:02:58 -0500 Jeff Garzik wrote: > On 01/05/2010 03:47 PM, Pete Zaitcev wrote: > > On Tue, 22 Dec 2009 22:36:16 -0500 > > Jeff Garzik wrote: > > > >> Seems like a mutex-wrapped GLib hash table would work... > > > > I dunno about this... See, I think it's like kernel timers: there's a > > lot of premium on having add and remove quick, and the rest is whatever. > > The important part is not to penalize the latency of normal requests > > only to make self-checking faster. That process takes hours to loop > > anyway, maybe days. > > > > I went with a list for now. > > How is an O(n) list faster than an O(1) hash table? Do you know what the constant is in that hash table (which is not O(1) in case of conflicts)? Notice that the glib's hash table does NOT include a hash function. This is something I wanted to discuss too. What would you use? I researched what's available, and all of them come with rather weird licenses (well, ok, Google hash is under the new BSD, which works for us... or does it?). The code is supposed to be easy to change over to any other lookup structure, hopefuly anyway. -- Pete