[Mulgara-dev] ResolverFactory export support
Alex Hall
alexhall at revelytix.com
Tue Jun 24 23:20:14 UTC 2008
Now that I've decided to add a supportsExport() method to the
ResolverFactory interface, I realize that I have to go through and
actually classify all the factories. Here is my first stab at a list,
with comments as appropriate:
== Does support export ==
1. StatementStoreResolverFactory (it certainly better!)
2. RemoteResolverFactory - Exporting the contents of a remote graph is
possible, but it could result in streaming a large amount of data across
the wire.
3. FileResolverFactory/JarResolverFactory/HttpResolverFactory - These
are the protocol handlers for external RDF content. Exporting an
external graph is essentially a file copy.
4. FileSystemResolverFactory - An internal constructed graph, but
supports resolving the ($s $p $o) constraint.
5. GISResolverFactory - Stores its content in a Mulgara graph
6. MemoryResolverFactory
7. NullResolverFactory - Even though the contents of the export will
always be empty.
8. ViewResolverFactory
9. URLResolverFactory - Is this factory even used any more?
== Does not support export ==
10. LuceneResolverFactory - Requires a literal in the object position
11. NodeTypeResolverFactory/PrefixResolverFactory/XSDResolverFactory -
These are the default internal constructed graphs with no actual content.
12. RelationalResolverFactory - Essentially an external constructed graph.
13. TestResolverFactory - Used for unit testing the custom constraints.
== Special cases ==
14. CacheResolverFactory/InternalResolverFactory - These are used
internally by the database to wrap external and internal factories,
respectively, to do special processing. They delegate to the wrapped
factory instance to answer supportsExport()
I welcome any comments on this list.
Regards,
Alex
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