Implement a Virtuoso Open-Source Search service

I believe the version I have locally supports SPARQL Update (http://docs.openlinksw.com/virtuoso/rdfsparql.html) and it may support other methods as well, so I will investigate and, if so, write multiple implementations to benchmarking. I imagine that seomwhere in the conifugration UI, I'll request to Drupal user for a Virtuoso username/password that has rights to the SPARQL_UPDATE Virtuoso user-group, but it looks like I can handle that with the SearchApiAbstractService methods. I'll keep this thread posted of progress, and feel free to get in touch anytime.

I've got a proof of concept working at: https://github.com/ashepherd/rdf_virtuoso

What's the best way to "collaborate". Should I create a Drupal.org sandbox for this and go down the path of creating a separate module? Soon, I'll get a chance to test it out with some data to see how well it performs.

Using devel generate, I created 1000 nodes which took about 20 seconds on my laptop. I then indexed those, verified they exist in Virtuoso, and that took about 20 seconds as well. I have a Drupal site on a larger server with 500,000 nodes, so I'm going to try it out there.

{UPDATE}
My dev server running a bunch of sites, and not optimized, updated the same Virtuoso instance (on the same server) with 583,282 nodes in 2hours and 12min averaging about 4,419 nodes per minute.

I really like your idea of a base class which which would remove a lot of my dupe code. I'm happy to write the base class and submit a patch including the service.virtuoso.inc file w/ an updated rdf_indexer_search_api_service_info()

Here is the patch with a base class and the virtuoso Service.

In testing, I've found that the entity module is causing problems with:

1. book module via: https://drupal.org/node/1330086
2. anonymous content when using devel generate via: https://drupal.org/node/1237014

Here is an updated version of the patch:

It fixes a few Virtuoso issues:

1. queries might be longer than what an HTTP GET request might be able to handle, so I've converted this Service to use HTTP POST
2. Virtuoso has a limit on the length of a query (default is 10,000 lines of code). This only effects INSERT queries since DELETE queries are small. I've made the module count the number of triples and make multiple insert queries if necessary

My apologies!

I separated out the ARC2 implementation into it's own file, and I modified the logic for when deleteItems is passed $ids = 'all'. Originally, is I saw 'all' I was clearing the entire graph. However, if another index is also writing to the same graph (let's say someone setup separate indexes for nodes, taxonomy terms, or other entity types), it was wiping out another indexes data. I left the clearGraph() line in the code, but commented it out in service.inc

I'm an idiot. Forgot to run 'git add' before creating the patch.

Hi Steph,

Here is the latest version of the Virtuoso Service. It patches branch 7.x-1.x, and adds a base service class which the ARC2 & Virtuoso service implement.

cheers, Adam

Latest version of patch fixes bug of unescaped forward slashes and adds support for xml:lang