pjs/db/tripledb

This is the TripleDB, a way of persistently remembering "triples" of data.

Each entry is kind of a "subject-verb-object" set. For example, some
entries might be:

Noun            Verb            Object
=========================================
File1           Length          1253254
File1           MimeType        text/html
File1           Author          Ralph
File2           Length          32542
File2           MimeType        image/gif
File2           Author          Bertha


This API is about storing, deleting, and querying such triples to a
database. Each member of a triple can be a string, integer, or date.

For more details, read the API, in tdbapi.h.

Note that TripleDB now depends on the Sleepycat Berkeley DB, version
3.1.11 or greater.  For more information on that, see
http://www.sleepycat.com.


FAQ:

Q: "Hey!  There's no Makefile!"
A: Yeah, yeah, I know.  This is developed as part of a project at
work, and our Makefiles are all messed up.  If you have one that fits in well
with other stuff at mozilla.org, please feel free to contribute it.

Q: Um, so nobody else here uses this?
A: That's right.  But this maps in pretty well to RDF, I believe.  I wouldn't
be surprised if someone decides to use it to store a biggish RDF database,
and adds it to mozilla for that purpose.



- Terry Weissman                        terry@mozilla.org