Second Life Wiki - User contributions [en]

Talk:LLSD

2008-12-17T06:34:54Z

Tammy Nowotny: /* base85 considered harmful */

{{Open Source Talk Page}}

== LLSD JSON-ish notation ==

The login sequence appears to use "binary" LLSD for two of the variables, home and look_at. Unfortunately the format doesn't match up exactly with what is documented on this wiki. Sample values:

{'region_handle':[r255232, r256512], 'position':[r33.6, r33.71, r43.13], 'look_at':[r34.6, r33.71, r43.13]}

[r0.99967899999999998428,r-0.025334599999999998787,r0]

No size values, and the map keys are encased in single quotes. Is this normal? -- {{Unsigned|Eddy Stryker}}

:Oh wow, notation format. Ummmmm, I never documented that, did I. LLSD started it's life as a json-like language, with a well defined serialization which is not actually documented. I'll get on that. [[User:Phoenix Linden|Phoenix Linden]] 16:10, 6 April 2007 (PDT)
:Documentation has been added. [[User:Phoenix Linden|Phoenix Linden]] 17:34, 12 April 2007 (PDT)

== Versioning? ==

Personally I miss a few things here, especially the versioning/compatibility. Sure you can asume that older request just have less keys in a map, and that might work well for things like statistics results. But as soon as you want to call a method, it is much better to make the version obvious. You can encode that in a key/value pair, but it is much better to have that in a fixed element for routing (you can route requests for inventories to different servers, depending on the interface version)

I see a Version:i1 in the notation example for the teleport, which makes it clear, that this element is used already in LL. Maybe it is hard for you to make it to a llsd envelop, but I think you guys will have great use for it.

<pre><llsd>
<method version="1" interface="simstatistics" message="result" />
...</pre>

or something like that.--[[User:Bernd Elswit|Bernd Elswit]] 10:27, 18 May 2007 (PDT)

== Efficient binary support ==

maybe a more efficient binary transport can be added, too? For example Adobe's ASCII85 allows better compression (however you need to escape less-than and ampersand and CDATA). Very efficient could be precalculated huffman tables for the most common file formats.

Sample code at the end of the page: http://www.javaworld.com/javaworld/javatips/jw-javatip117.html

--[[User:Bernd Elswit|Bernd Elswit]] 10:26, 18 May 2007 (PDT)

:Any time that we need to conserve space or cpu resources, we will use zlib routines or [[LLSD#Binary_Serialization|binary serialization]]. [[User:Phoenix Linden|Phoenix Linden]] 12:41, 21 May 2007 (PDT)

== hexadecimal ? ==

does the integer type allow hexadecimal values ? e.g. 0xffcc00 instead of entering 16763904 ?

[[User:SignpostMarv Martin|SignpostMarv Martin]] 09:54, 31 May 2007 (PDT)

== Binary map and array encoding ? ==
The description is not clear how the delimiters for map and array elements should be encoded.
See here:

<pre>
array '[' + htonl(array.length()) + ''(''child0'','' child1'','' ...'')'' + ']'

map '{' + htonl(map.length()) + ''((''key0'',''value0''),(''key1, value1''),'' ...'')'' + '}'
</pre>

Especially the binary encoding of the <pre>''</pre> marked values is not defined. As I am sitting at an implementation of this, I will try with the supposed reference implementation llsd.py and see what that actually does for this part.
--[[User:Leffard Lassard|Leffard Lassard]] 10:04, 27 March 2008 (PDT)

From my own research it is more like this:

<pre>
array '[' + htonl(array.length()) + child0 + child1 + ']'

map '{' + htonl(map.length()) + 'k' + htonl(key0.length) + key0 + value0 + 'k' + htonl(key1.length) + key1 + value 1 ... + '}'
</pre>

--[[User:Leffard Lassard|Leffard Lassard]] 11:26, 28 March 2008 (PDT)

== XML <-> Notation? ==

The XML format is, let's face it, not fun to read or write, for humans, in those weird cases where humans have to. Is there a serialization converter, somewhere, or should I just rig my own? --[[User:Ky Aska|Ky Aska]] 06:12, 3 June 2008 (PDT)

== Motivations Behind LLSD ==

Just a quick note to say i've been having discussions with peeps about why LLSD was invented in the first place; more discussions than I ever thought I would have on the subject. The best answer I could give was a) we like dynamic data models and b) it helps a bit to avoid the Fragile Binary Interface problem. If we ever get around to updating the intro, we may want to mention why dynamic data models are "nice" from an agile programming perspective and why FBI is bad. And BTW, here's the wikipedia entry on FBI: http://en.wikipedia.org/wiki/Fragile_binary_interface_problem . --[[User:Infinity Linden|Infinity Linden]]

== base85 considered harmful ==

Please note: base85 as an encoding for binary elements in the XML serialization of LLSD data is not canonical.

==about integers and real numbers==
In the quote-unquote "real" world there are an infinite number of integers, and real numbers truly go up to infinity. Is there any work being done to support numbers higher than the current limits, and does this have any relevance to the LLSD standard? It seems to me we at least have to make it easily extendible, since it may be around for several (or even many) decades. [[User:Tammy Nowotny|Tammy Nowotny]] 06:34, 17 December 2008 (UTC)

User:Tammy Nowotny

2008-09-29T01:03:36Z

Tammy Nowotny: initial profile

I am a bit of a Jill of All Trades in Second Life. I especially enjoy making (or even just giving away as freebies) T shirts and ladies' dresses. I am a somewhat active participant (to borrow a phrase from [[User:Dale_Innis|Dale Innis]]) in the [[Architecture Working Group]]. The AWG is of special interest to me because it ties in with my work in past Real Lives as an accounting database developer and as a data analyst for the Army Corps of Engineers: I am very interested in how data modesl and technical standards evolve.

In addition to IM, I can be emailed at TammyNowotny@mac.com

I am hoping to find a job which can support myself, my avatars and even my real life self (who shockingly is soon to be a member of the New Hampshire State House of Representatives, which is a part-time citizen legislature.) Something which combined both Second and First Life would be ideal for me.

{{Jira Reporter}}

User:Tammy Nowotny

2008-09-29T01:03:00Z

Tammy Nowotny:

I am a bit of a Jill of All Trades in Second Life. I especially join or making (or even just giving away as freebies) T shirts and ladies' dresses. I am a somewhat active participant (to borrow a phrase from [[User:Dale_Innis|Dale Innis]]) in the [[Architecture Working Group]]. The AWG is of special interest to me because it ties in with my work in past Real Lives as an accounting database developer and as a data analyst for the Army Corps of Engineers: I am very interested in how data modesl and technical standards evolve.

In addition to IM, I can be emailed at TammyNowotny@mac.com

I am hoping to find a job which can support myself, my avatars and even my real life self (who shockingly is soon to be a member of the New Hampshire State House of Representatives, which is a part-time citizen legislature.) Something which combined both Second and First Life would be ideal for me.

{{Jira Reporter}}

Talk:Limits

2008-07-15T18:43:58Z

Tammy Nowotny:

== Ban List Limit ==
This page says that the number of people in an estate ban list is limited to 500. As far as I know, it's been 300 for a year or so. Did this change recently, maybe in the RC client? [[User:Lex Neva|Lex Neva]] 10:31, 5 July 2008 (PDT)
:I'm not a pro on this so it is just a guess, but I would tend to think that the limit change would be connected to new simulator software, rather then to a new client, since the sim stores the list of people who aren't allowed to enter. The client is just displaying it(?)
:That beeing said, please browse to {{Jira|SVC-747}} and watch for the comment made by [[User:Seraph Linden|Seraph Linden]] at 11/Jan/08 07:59 AM
:Because of the date, in case it was a client issue, then it should be at least fixed since 1.19
:Greetz, =) [[User:Zai Lynch|Zai Lynch]]<sup>([[User talk:Zai Lynch|talk]]|[[Special:Contributions/Zai Lynch|contribs]])</sup> 11:29, 5 July 2008 (PDT)

== Prim Size Limits ==

I once saw instructions on how to make a prim that's larger than 10x10 but that the system considers to be 10x10. It isn't a megaprim and anyone can do it. It's a flat diamond shape. Does anyone know how? --[[User:Shadoe Landman|Shadoe Landman]] 13:04, 6 July 2008 (PDT)

You can create >10m disks from tubes, rings, and torii. Set the twist Twist at: Begin: 90, End: 90, and Hole Size at: X: 1.00, Y: 0.05. --[[User:McCabe Maxsted|McCabe Maxsted]] 23:38, 8 July 2008 (PDT)

==Avis per region limits++
The limits on the number of avatars per region are soft limits, I beliece... i.e., if you have more than that many avis on the sim, the server slows down and crashes. Is the larger number listed for a private estate sim caused by the fact that there are (typically) a very small number of other sims which can see that sim? [[User:Tammy Nowotny|Tammy Nowotny]] 11:43, 15 July 2008 (PDT)