We've now got a new notmuch_query_search_threads and a
notmuch_threads_result_t iterator. The thread object itself
doesn't do much yet, (just allows one to get the thread_id),
but that's at least enough to see that "notmuch search" is
actually doing something now, (since it has been converted
to print thread IDs instead of message IDs).
And maybe that's all we need. Getting the messages belonging
to a thread is as simple as a notmuch_query_search_messages
with a string of "thread:<thread-id>".
Though it would be convenient to add notmuch_thread_get_messages
which could use the existing notmuch_message_results_t iterator.
Now we just need an implementation of "notmuch show" and we'll
have something somewhat usable.
Along with renaming notmuch_results_t to notmuch_message_results_t.
The new type is quite a mouthful, but I don't expect it to be
used much other than the for-loop idiom in the documentation,
(which does at least fit nicely within 80 columns).
This is all in preparation for the addition of a new
notmuch_query_search_threads of course.
Instead of supporting multiple thread IDs, we now merge together
thread IDs if one message is ever found to belong to more than one
thread. This allows for constructing complete threads when, for
example, a child message doesn't include a complete list of References
headers back to the beginning of the thread.
It also simplifies dealing with mapping a message ID to a thread ID
which is now a simple get_thread_id just like get_message_id, (and no
longer an iterator-based thing like get_tags).
The current problem is that when this function fails the caller
doesn't get any information about what the particular failure
was, (something in the filesystem? or in Xapian?). We should fix
that.
The notmuch_database_get_default_path function is unique in not
accepting a notmuch_database_t* (nor creating one). So list it
outside the other notmuch_database functions.
And document that notmuch_database_add_message can return this
value. This pushes the hard decision of what to do with duplicate
messages out to the user, but that's OK. (We weren't really doing
anything with these ourselves, and this way the user is at least
informed of the issue, rather than it just getting papered over
internally.)
This were just unclean, (an invisble sort of uncleanliness, but still
there are liable to make for ugly diffs). Oh, wait, like this one!
But at least it's not sprinkled among code changes.
With the recent improvements to the handling of message IDs we
"know" that a NULL message ID is impossible, (so we simply
abort if the impossible happens).
This is a new public function to find the filename of the original
email message for a message-object that was found in the database.
We may change this function in the future to support returning a
list of filenames, (for messages with duplicate message IDs).
This is important as we're using the message ID as the unique key
in our database. So previously, all messages with no message ID
would be treated as the same message---not good at all.
This is where we wanted to put the note to recommend the user
call notmuch_message_destroy if the lifetime of the message
is much shorter than the lifetime of the query. (Somehow this
had ended up in the documentation of notmuch_message_get_tags
before.)
With this function, and the recently added support for
notmuch_message_get_thread_ids, we now recode the find_thread_ids
function to work just the way we expect a user of the public
notmuch API to work. Not too bad really.
Along with all of the notmuch_thread_ids_t iterator functions.
Using a consistent idiom seems better here rather than returning
a comma-separated string and forcing the user to parse it.
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").
When documenting these functions I described support for a
NOTMUCH_BASE environment variable to be consulted in the case
of a NULL path. Only, I had forgotten to actually write the
code.
This code exists now, with a new, exported function:
notmuch_database_default_path
This is helpful for things like indexes that other mail programs
may have left around. It also means we can make the initial
instructions much easier, (the user need not worry about moving
away auxiliary files from some other email program).
This is the beginning of the notmuch library as well, with its
interface in notmuch.h. So far we've got create, open, close, and
add_message (all with a notmuch_database prefix).
The current add_message function has already been whittled down from
what we have in notmuch-index-message to add only references,
message-id, and thread-id to the index, (that is---just enough to do
thread-linkage but nothing for full-text searching).
The concept here is to do something quickly so that the user can get
some data into notmuch and start using it. (The most interesting stuff
is then thread-linkage and labels like inbox and unread.) We can
defer the full-text indexing of the body of the messages for later,
(such as in the background while the user is reading mail).
The initial thread-stitching step is still slower than I would like.
We may have to stop using libgmime for this step as its overhead is
not worth it for the simple case of just parsing the message-id,
references, and in-reply-to headers.
