Re: [xdi] Read-only/Append-only (was Re: Notation shift)

["=Drummond Reed" <drummond.reed@xdi.org>]

Markus, thanks. I agree this issue is important enough to add the agenda for this week's XDI TC call, which although I'll be in Switzerland I should be able to make for the first time in a month.

At first blush I can see the case for being able to make branches of the graph write-once read-only. I'm wonder whether we could get that not be re-introducing $add and $mod in addition to $set, but by specializing $set to include $set$once. That would enable you to only write the data once.

=Drummond 

On Thu, Jul 10, 2014 at 10:02 AM, Markus Sabadello <markus.sabadello@xdi.org> wrote:

(changing subject, and adding XDI TC as recipient)

We used to distinguish between a $add and a $mod operation. The former would only allow writing new data to a graph, whereas the latter would only allow modifying existing data. At some point we decided to merge both operations into a single $set operation.

I'll add this topic to the agenda of the next XDI TC call.

Markus

On Tue, Jul 8, 2014 at 2:49 AM, Matthew Sutton <matthew@respectnetwork.net> wrote:

I know I don't post often here but from a product point of view the notion of having a write once, read only type of data could be extremely important in the not too distant future.

Medical records and legal records, for example, would require the ability of a doctor or lawyer to write a bit of data, a medical record for example, but no one can ever change that field in the future.  We will struggle to gain acceptance in those fields if we cannot ensure that data is written and cannot be changed.

Now it may be that this occurs outside of XDI, if so I would like to understand how.

Matthew

On Mon, Jul 7, 2014 at 1:41 PM, Markus Sabadello <markus@respectnetwork.net> wrote:

In general, there is no such thing as "read-only" in XDI.

Permission to read/write/del is governed by link contracts.

I could imagine an implementation-specific feature of XDI2 that would prevent changes to certain parts of the graph.
Actually, there IS such a feature already today, the ReadOnlyInterceptor.

But again, the question is if such a feature would be considered implementation-specific, or if we include this in the XDI spec.

Markus

On Tue, Jul 8, 2014 at 6:33 AM, Zhang, Ning <Ning.Zhang@neustar.biz> wrote:

This should be a read-only literal, right?

 

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From: markus.sabadello@gmail.com [mailto:markus.sabadello@gmail.com] On Behalf Of Markus Sabadello
Sent: Monday, July 07, 2014 4:08 PM
To: Chowdhury, Animesh
Cc: Chasen, Les; Dev; Andrew Dally; Zhang, Ning; * PCloud - Support
Subject: Re: Notation shift

 

Yes, I don't see a problem with adding such a literal to the graph.

Could be done automatically by the BootstrapInterceptor, or through an explicit XDI message sent by the CSP SDK.

Markus

 

On Tue, Jul 8, 2014 at 5:07 AM, Chowdhury, Animesh <Animesh.Chowdhury@neustar.biz> wrote:

Hi,

As far as creation date of a graph is concerned, it’s not in the graph now, neither it is in the CSP graph.

The date in the MongoDB ( for _id field) is only as good as the last time a graph was created. So, for notation shifts or wholesale move of graphs, those dates are re-created too.

I think the right way to preserve the creation date is to have the date in the graph itself as a literal value. This literal can be created when the graph is created , just like the keypairs in a graph.

 

Markus,

What’s your thought on creating a literal in the graph for personal cloud creation date ?

 

 

Thanks,

Animesh

 

From: Chasen, Les
Sent: Thursday, July 03, 2014 10:33 PM
To: Markus Sabadello
Cc: Dev; Chowdhury, Animesh; Andrew Dally; Zhang, Ning
Subject: Re: Notation shift

 

Animesh?  

 

They are there somewhere?  Maybe in the CSP graph?

 

From: Markus Sabadello <markus@respectnetwork.net>
Date: Thursday, July 3, 2014 at 6:58 PM
To: Les Chasen <les.chasen@neustar.biz>
Cc: Dev <dev@respectnetwork.net>, "Chowdhury, Animesh" <Animesh.Chowdhury@neustar.biz>, Andrew Dally <adally@ownyourinfo.com>, "Zhang, Ning" <Ning.Zhang@Neustar.biz>
Subject: Re: Notation shift

 

We don't have creation dates inside the XDI graphs.

Maybe those creation dates are somehow externally attached to the XDI graphs?

If that's the case, I would not know where they come from or how to retain them.

Markus

 

On Thu, Jul 3, 2014 at 3:32 PM, Chasen, Les <les.chasen@neustar.biz> wrote:

+ ning

 

Each of the past two times we have done this the graphs were each recreated brand new with new creation dates.   It is preferable for clouds to retain their original creation dates.  

On Jul 3, 2014, at 3:21 PM, "Markus Sabadello" <markus@respectnetwork.net> wrote:

I wrote up what I think it takes to do the notation shift:
https://github.com/projectdanube/xdi2-tools/wiki/Notation-Shift

My hope is that maybe we can do this while Animesh is still involved.

Any suggestions for a good time to do this?
Maybe shortly after the RN tour?

 

I think Andrew won't have to change anything, since he's using a notation that will remain the same after shift.

Markus