Message-ID: <1488839459.2134.5.camel@mmci.uni-saarland.de>
From: Tim Ruffing <tim.ruffing@mmci.uni-saarland.de>
To: Luke Dashjr <luke@dashjr.org>, bitcoin-dev@lists.linuxfoundation.org
Date: Mon, 06 Mar 2017 17:30:59 -0500
In-Reply-To: <201703062214.47660.luke@dashjr.org>
References: <201703040827.33798.luke@dashjr.org>
	<201703060709.40311.luke@dashjr.org>
	<1488837256.2134.1.camel@mmci.uni-saarland.de>
	<201703062214.47660.luke@dashjr.org>
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Subject: Re: [bitcoin-dev] Currency/exchange rate information API
Precedence: list

On Mon, 2017-03-06 at 22:14 +0000, Luke Dashjr wrote:
> 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?
Yes, that solves it. You're right with the privacy concern however.

> 
> > 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.
Oh sure, I had overlooked that.

> 
> > 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?
That works but a standardized way of indicating that piece of
information to the client is useful. Then the client can display a
"connection status" to the user, e.g., an "possible out-of-date"
warning like the warning sign in the Qt GUI when Bitcoin Core is
catching up the network.


Tim