serde-llsd

Serialization library for Linden Lab Serial Data format. Rust/Serde version.

Linden Lab Structured Data (LLSD) serialization

This is a serialization system used by Second Life and Open Simulator. It is documented here: http://wiki.secondlife.com/wiki/LLSD

Introduction

There are three formats - XML, binary, and "Notation". All store the same data, which is roughly the same as what JSON can represent. Parsing and output functions are provided.

Status

XML, binary, and Notation versions are implemented.

Unit tests pass. Tested against Second Life asset servers and Open Simulator servers. Used by the Sharpview metaverse viewer.

Data types

• Boolean - converts to Rust "bool".

• Integer - Rust i32.

• Real - Rust f64

• UUID - Rust [u8;16]

• String - Rust String, Unicode

• Date - "an absolute point in time, UTC, with resolution to the second", as Rust i64.

• URI - Rust String that is a URI

• Binary - Vec

• A map is a HashMap mapping String keys to LLSD values.

• An array is a Rust Vec of LLSD values.

Field access

The enum_as_inner crate is used to derive access functions for each field type. So, given an LLSDValue llsdval which is expected to be an Integer,

let n = *llsdval.as_integer().unwrap();

will yield the integer value.

LLSD values in Rust

These generally follow the conventions of the Rust crate "json". An LLSD value is a tree.

Character sets

Notation is divided into a byte stream form and a string from.

The byte stream form supports all the formats defined for LLSD, including byte-counted strings and binary values. Only single-byte ASCII characters are allowed. Byte stream form Notation cannot be placed inside LLSD XML, because the byte streams will not be valid UTf-8.

The string form is valid UTF-8, but will not accept byte-counted strings or binary values. Binary values must be in hex or Base64 format. String-form Notation can be placed inside LLSD XML.

Known problems.

• "Notation" fomat input will not currently accept infinity or NaN values.

• Error messages do not indicate the source of the problem in the incoming stream.