Maturity Level

[dukesook]

Hello,

I'm looking for a C++ RDF library that is suitable for a production environment. Can you help me understand how stable rdf4cpp is? Is it close to a 1.0 release? Or would you recommend going with another library like Redland?

[bigerl]

Hi Devon,

it's time we update the readme in that regard. The user-facing API has been stable for a while now. This is also the focus of rdf4cpp: make it as easy as possible to work with RDF nodes, provide all the XSD datatypes and functions at your finger tip and allow developers to easily switch back and forth between RDF and C++ land.

The only thing not yet fully stable are internals, like identifiers and datastructures. This is only a concern if you plan to build a custom backend that persist the node storage, e.g., to not have to parse a graph again when restarting your application.

The primary driver of developing rdf4cpp has been to have a fast, easy to use and correct implementation of RDF, XSD datatypes and XPath Functions and Operators for the triplestore Tentris. So, things are tested thoroughly but sometimes documentation might be a bit focused on that particular use case.

We are planning to have a v0.1 soon. This means that we will have stable user-facing APIs within minor versions but non-stable backend. We plan for this version to have the same user-facing API as the current release v0.0.51.

Hope that helps.

If I might ask: What will be your use-case?

[dukesook]

Thanks for the response.

What will be your use-case?

I'm part of the geospatial community which is adopting RDF to store metadata for satellite imagery. The C++ group won't need persistent node storage anytime soon, so rdf4cpp seems like a good solution for them.

[bigerl]

Great to hear.

I would guess you are using GeoSPARQL then. What also might be interesting for you is that the type system of rdf4cpp is extensible. If you require native support for Geometry Serialization RDF literals and the associated functions (1,2), that would be a very welcome contribution. Currently, you can of course define such literals but they are not checked for validity.
rdf4cpp supports specialized literal node storages where literals with a specific datatype are backed by native C++ types instead of their string representation.
This also makes it simple to implement functions that receive such literals as arguments or return them.

[dukesook]

Yes, we're interested in using GeoSPARQL, thanks for the reference. That's good to know that the types are extendable, I might look into such a contribution in the future.

[dukesook]

rdf4cpp::rdf::Graph: A Collection of Statements, with the ability to execute simple Queries.

Does rdf4cpp have a built-in SPARQL engine for querying? What kinds of queries can it do or not do?

[bigerl]

No, rdf4cpp itself does not include a SPARQL engine.

However, I am the co-founder of the company Tentris GmbH, which develops TentrisDB, a commercial spinoff of the research prototype Tentris. TentrisDB features a very fast SPARQL engine built on rdf4cpp, supporting full SPARQL 1.1.

If you're interested in learning more about TentrisDB or integrating its engine as a library, please contact me on LinkedIn or via email.