Here's the big bug that was preventing any searches from working at
all like desired. I did the work to carefully pick out exactly the
flags that I wanted, and then I threw it away by trying to combine
them with & instead of | (so just passing 0 for flags instead).
Much better now.
It's nice that Xapian provides a little function to print a textual
representation of the entire query tree. So now, if you compile
like so:
make CFLAGS=-DDEBUG_QUERY
then you get a nice output of the query string received by the query
module, and the final query actually being sent to Xapian.
To properly support sorting in notmuch_query we know use an
Enquire object. We also throw in a QueryParser too, so we're
really close to being able to support arbitrary full-text
searches.
I took a look at the supported QueryParser syntax and chose
a set of flags for everything I like, (such as supporting
Boolean operators in either case ("AND" or "and"), supporting
phrase searching, supporting + and - to include/preclude terms,
and supporting a trailing * on any term as a wildcard).
Using the address of a static char* was clever, but really
unnecessary. An empty string is much less magic, and even
easier to understand as the way to query everything from
the database.
None of these are strictly necessary, (everything was leak-free
without them), but notmuch_message_destroy can actually be useful
for when one query has many message results, but only one is needed
to be live at a time.
The destroy functions for results and tags are fairly gratuitous, as
there's unlikely to be any benefit from calling them. But they're all
easy to add, (all of these functions are just wrappers for talloc_free),
and we do so for consistency and completeness.
This is a fairly big milestone for notmuch. It's our first command
to do anything besides building the index, so it proves we can
actually read valid results out from the index.
It also puts in place almost all of the API and infrastructure we
will need to allow searching of the database.
Finally, with this change we are now using talloc inside of notmuch
which is truly a delight to use. And now that I figured out how
to use C++ objects with talloc allocation, (it requires grotty
parts of C++ such as "placement new" and "explicit destructors"),
we are valgrind-clean for "notmuch dump", (as in "no leaks are
possible").
