From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 99254C1D for ; Mon, 6 Mar 2017 22:15:26 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from zinan.dashjr.org (zinan.dashjr.org [192.3.11.21]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 3DD89106 for ; Mon, 6 Mar 2017 22:15:26 +0000 (UTC) Received: from ishibashi.localnet (unknown [IPv6:2001:470:5:265:a45d:823b:2d27:961c]) (Authenticated sender: luke-jr) by zinan.dashjr.org (Postfix) with ESMTPSA id 61D6F38ABEB6; Mon, 6 Mar 2017 22:14:48 +0000 (UTC) X-Hashcash: 1:25:170306:tim.ruffing@mmci.uni-saarland.de::VIhgcsbsZWvBksBf:aufLL X-Hashcash: 1:25:170306:bitcoin-dev@lists.linuxfoundation.org::aD5R1vjcIMlB4hb7:dS5=H From: Luke Dashjr To: Tim Ruffing Date: Mon, 6 Mar 2017 22:14:47 +0000 User-Agent: KMail/1.13.7 (Linux/4.4.45-gentoo; KDE/4.14.28; x86_64; ; ) References: <201703040827.33798.luke@dashjr.org> <201703060709.40311.luke@dashjr.org> <1488837256.2134.1.camel@mmci.uni-saarland.de> In-Reply-To: <1488837256.2134.1.camel@mmci.uni-saarland.de> X-PGP-Key-Fingerprint: E463 A93F 5F31 17EE DE6C 7316 BD02 9424 21F4 889F X-PGP-Key-ID: BD02942421F4889F X-PGP-Keyserver: hkp://pgp.mit.edu MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <201703062214.47660.luke@dashjr.org> X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: bitcoin-dev@lists.linuxfoundation.org Subject: Re: [bitcoin-dev] Currency/exchange rate information API X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 06 Mar 2017 22:15:26 -0000 On Monday, March 06, 2017 9:54:16 PM Tim Ruffing wrote: > Having the rate at the time of payment is indeed very useful, yes. > However that requires just a single value per payment, and there is no > query that tells the server "give me the value closest to timestamp t" > or similar. > Of course the client can download and keep a large part of history and > extract the information on its own but I can imagine that not every > clients wants to do that, and also the client does not know in advance > the bounds (from, to) that it must query. It would be a privacy leak to request only the specific timestamps, but I suppose many wallets lack even basic privacy to begin with. To address the bounds issue, I have specified that when from/to don't have an exact record, that the previous/next (respectively) is provided. Hopefully this addresses both concerns? > In the current draft the client or the server cannot specify > granularity. If the clients only wants one value per day but for an > entire year, then it has to perform many requests or download and > process a very large response. That's what the "timedelta" field solves, no? If you want one value per day, you'd put 86400. > Also, I think it's okay that the type field allows for arbitrary user- > defined values, but it should also have some precisely defined values > (e.g. the mentioned low/high/open/close/typical). > For example, it's not clear currently what "low" means for a timestamp > (as opposed to a time span). Is it the low of the entire day or the low > since the previous record or something different? Is it not sufficient for the server to specify this in the description of the given currency-pair feed? Luke