This cleans up some old code that was very ugly, (separately opening
the mail file and seeking to the end of the headers to parse the
body). I knew gmime must have had support for transparently decoding
mime content, but I just couldn't find it previously.
Note: Multipart and MultipartSigned parts are not handled yet.
Things are quite happy now. The few differences I see with sup are:
1. sup forces email address domains to lowercase, (I don't think I care)
2. sup and notmuch disagree on ordering of multiple thread_id values
(another thing that's of no concern)
We are still doing one thing wrong when a message belongs to multiple
threads. We've got a nice comma-separated thread-value just like sup,
but then we're also putting in a comma-separated thread-term where
sup does multiple thread terms. That should be an easy fix.
Beyond that, sup and notmuch are still disagreeing on the term lists
for some messages, (I think attachment vs. inline content-disposition
is at least one piece of this). But there are likley still differences
in the heuristics for which chunks of the message body to index. I'll
be looking into this more.
Currently we're looking up all parents (based on In-reply-to and
References header) and using the list of all thread_id values
from those as our thread_id value. We're missing one step which
sup does which is to also look up any children in the database
that have reference our message ID. So we'll need to do that next.
This is in preparation for doing a couple of passes over the references,
(one to add terms to the database, and a second to find the thread_id).
We also now parse the In-reply-to header which we were missing before.
We treat it identically to the References header.
We identify it based on a trailing ':' on the line before a quote
begins.
At this point the database-dump diff between sup and notmuch is
getting very, very small, (at least for our one test message).
At this point, we're achieving a result that is *very* close to
what sup does. The only difference is that we are still indexing
the "excerpts from message ..." line, and we are not yet indexing
references.
Most of this code is fairly clean and works well. One part is
fairly painful---namely extracting the body of an email message
from libgmime. Currently, I'm just extracting the offset to
the end of the headers, and then separately opening the message.
Surely there's a better way.
Anyway, with that the results are looking very similar to sup-sync
now, (as verified by xapian-dump). The only substantial difference
I'm seeing now is that sup does not seem to index quoted portions
of messages nor signatures. I'm not actually sure whether I want
to follow sup's lead in that or not.
