On 29/12/13 20:40, Claude Warren wrote:
The RMI simply exposes an existing graph implementation on a remote system.
The normal disclaimers apply but given the standard Jena configuration:
NodeFactory.createAnon() uses UID to create an id that would be passed to
the graph on the remote server where the anon would be recreated.
The result is that both the client and the server have the same anon id for
the blank node.
Am I missing something?
Only that UID are, strictly, only unique for the machine they are
allocated on. RMI etc can pass them around but they only safely
identify things on the same machine as their origin (they aren't long
enough for wider uniqueness). Its the UID user's responsibility nor to
present them on on a non-origin machine.
Ideally, Jena3, I'd like to use UUIDs, and then store only two longs,
for blank nodes. They they are globally safe as well as being smaller.
Out of curiosity - why do you need to extend to Model? Is there a
client-side implementation of graph and then it's just a case of
wrapping a Graph just like another other graph? Or am I missing something?
Another issue in parsing is keeping label->bnode mapping. Labels must
be matched to any previous use in the parser run.
The RIOT parsers do not use jena-core UID generation for bnode ids.
If it's a map of label to node allocated, there is a growing data
structure. Something that we occasionally get reports of being a
problem as the map grows for very large parser runs.
Instead, RIOT allocates a large number (122 bits of random) and xors it
with the label. So the internal id is calculated from the label and is
unique yet there is no growing data structure.
Andy
Claude
On Sun, Dec 29, 2013 at 7:43 PM, Andy Seaborne <[email protected]> wrote:
On 29/12/13 16:58, Claude Warren wrote:
Greetings,
I have an initial implementation of an RMI based Graph that allows one JVM
to access a graph in a different JVM. I hope to extend this to the Model
level in the near future. I just wanted to know if anyone was interested
in this project.
Claude
The perennial question ...
How do you treat blank nodes?
Andy
