Tags in a notmuch database affect all messages with the identical
message-ID. But maildir tags affect individual files. And since
multiple files can contain the identical message-ID, there is not a
one-to-one correspondence between messages affected by tags and flags.
This is particularly dangerous with the 'T' (== "trashed") maildir
flag and the corresponding "deleted" tag in the notmuch
database. Since these flags/tags are often used to trigger
irreversible deletion operations, the lack of one-to-one
correspondence can be potentially dangerous.
For example, consider the following sequence:
1. A third-party application is used to identify duplicate messages
in the mail store, and mark all-but-one of each duplicate with
the 'T' flag for subsequent deletion.
2. A "notmuch new" operation reads that 'T' flag, adding the
"deleted" flag to the corresponding messages within the notmuch
database.
3. A subsequent notmuch operation, (such as a "notmuch dump; notmuch
restore" cycle) synchronized the "deleted" tag back to the mail
store, applying the 'T' flag to all(!) filenames with duplicate
message IDs.
4. A third-party application reads the 'T' flags and irreversibly
deletes all mail messages which had any duplicates(!).
In order to avoid this scenario, we simply refuse to synchronize the
'T' flag with the "deleted" tag. Instead, applications can set 'T' and
act on it to delete files, or can set "deleted" and act on it to
delete files. But in either case the semantics are clear and there is
never dangerous propagation through the one-to-many mapping of notmuch
message objects to files.
This adds group [maildir] and key 'synchronize_flags' to the
configuration file. Its value enables (true) or diables (false) the
synchronization between notmuch tags and maildir flags. By default,
the synchronization is disabled.
This patch allows bi-directional synchronization between maildir
flags and certain tags. The flag-to-tag mapping is defined by flag2tag
array.
The synchronization works this way:
1) Whenever notmuch new is executed, the following happens:
o New messages are tagged with configured new_tags.
o For new or renamed messages with maildir info present in the file
name, the tags defined in flag2tag are either added or removed
depending on the flags from the file name.
2) Whenever notmuch tag (or notmuch restore) is executed, a new set of
flags based on the tags is constructed for every message and a new
file name is prepared based on the old file name but with the new
flags. If the flags differs and the old message was in 'new'
directory then this is replaced with 'cur' in the new file name. If
the new and old file names differ, the file is renamed and notmuch
database is updated accordingly.
The rename happens before the database is updated. In case of crash
between rename and database update, the next run of notmuch new
brings the database in sync with the mail store again.
Previously we were using Xapian's add_document to allocate document ID
values for notmuch_message_t objects. This had the drawback of adding
a partially constructed mail document to the database. If notmuch was
subsequently interrupted before fully populating this document, then
later runs would be quite confused when seeing the partial documents.
There are reports from the wild of people hitting internal errors of
the form "Message ... has no thread ID" for example, (which is
currently an unrecoverable error).
We fix this by manually allocating document IDs without adding
documents. With this change, we never call Xapian's add_document
method, but only replace_document with either the current document ID
of a message or a new one that we have allocated.
message->authors contains the author's name (as we want to print it)
get / set methods are declared in notmuch-private.h
Signed-off-by: Dirk Hohndel <hohndel@infradead.org>
We rename 'has_more' to 'valid' so that it can function whether
iterating in a forward or reverse direction. We also rename
'advance' to 'move_to_next' to setup parallel naming with
the proposed functions 'move_to_first', 'move_to_last', and
'move_to_previous'.
The sequential identifiers have the advantage of being guaranteed to
be unique (until we overflow a 64-bit unsigned integer), and also take
up half as much space in the "notmuch search" output (16 columns
rather than 32).
This change also has the side effect of fixing a bug where notmuch
could block on /dev/random at startup (waiting for some entropy to
appear). This bug was hit hard by the test suite, (which could easily
exhaust the available entropy on common systems---resulting in large
delays of the test suite).
The WDF is the "within-document frequency" value for a particular
term. It's intended to provide an indication of how frequent a term is
within a document, (for use in computing relevance). Xapian's term
generator already computes WDF values when we use that, (which we do
for indexing all mail content).
We don't use the term generator when adding single terms for things
that don't actually appear in the mail document, (such as tags, the
filename, etc.). In this case, the WDF value for these terms doesn't
matter much.
But Xapian's flint backend can be more efficient with changes to terms
that don't affect the document "length". So there's a performance
advantage for manipulating tags (with the flint backend) if the WDF of
these terms is 0.
The first phase copies data from the old format to the new format
without deleting anything. This allows an old notmuch to still use the
database if the upgrade process gets interrupted. The second phase
performs the deletion (after updating the database version number). If
the second phase is interrupted, there will be some unused data in the
database, but it shouldn't cause any actual harm.
The recent support for renames in the database is our first time
(since notmuch has had more than a single user) that we have a
database format change. To support smooth upgrades we now encode a
database format version number in the Xapian metadata.
Going forward notmuch will emit a warning if used to read from a
database with a newer version than it natively supports, and will
refuse to write to a database with a newer version.
The library also provides functions to query the database format
version:
notmuch_database_get_version
to ask if notmuch wants a newer version than that:
notmuch_database_needs_upgrade
and a function to actually perform that upgrade:
notmuch_database_upgrade
Previously, many checks were deep in the library just before a cast
operation. These have now been replaced with internal errors and new
checks have instead been added at the beginning of all top-levelentry
points requiring a read-write database.
The new checks now also use a single function for checking and
printing the error message. This will give us a convenient location to
extend the check, (such as based on database version as well).
When a notmuch database is upgraded to the new database format, (to
support file rename and deletion), any message documents corresponding
to deleted files will not currently be upgraded. This means that a
search matching these documents will find no filenames in the expected
place.
Go ahead and return the filename as originally stored, (rather than
aborting with an internal error), in this case.
This new directory ojbect provides all the infrastructure needed to
detect when files or directories are deleted or renamed. There's still
code needed on top of this (within "notmuch new") to actually do that
detection.
The code to map a filename to a direntry is something that we're going
to want in a future _remove_message function, so put it in a new
function _notmuch_database_filename_to_direntry .
The library interface is unchanged so far, (still just
notmuch_database_add_message), but internally, the old
_set_filename function is now _add_filename instead.
Instead of storing the complete message filename in the data portion
of a mail document we now store a 'direntry' term that contains the
document ID of a directory document and also the basename of the
message filename within that directory. This will allow us to easily
store multple filenames for a single message, and will also allow us
to find mail documents for files that previously existed in a
directory but that have since been deleted.
We'll soon be having multiple entry points that accept a filename
path, so we want common code for getting a relative path from a
potentially absolute path.
This error was tirggered with a debugging build via:
make CXXFLAGS="-DDEBUG"
and reported by David Bremner. The actual error is that I'm an
idiot that doesn't know how to use strcmp's return value. Of
course, the strcmp interface scores a negative 7 on Rusty Russell
ranking of bad interfaces:
http://ozlabs.org/~rusty/index.cgi/tech/2008-04-01.html
This patch allows for different flags, internal to notmuch, to be set on a
message object. The patch does not define any such flags, just the
facilities to manage these flags.
Signed-off-by: Bart Trojanowski <bart@jukie.net>
This patch adds a new function called notmuch_database_get_all_tags
which can be used to obtain a list of all tags from the database
(in other words, the list contains all tags from all messages). The
function produces an alphabetically sorted list.
To add support for the new function, we rip the guts off of
notmuch_message_get_tags and put them in a new generic function
called _notmuch_convert_tags. The generic function takes a
Xapian::TermIterator as argument and uses the iterator to find tags.
This makes the function usable with different Xapian objects.
Function notmuch_message_get_tags is then reimplemented to call the
generic function with message->doc.termlist_begin() as argument.
Similarly, we implement notmuch_message_database_get_all_tags, the
function calls the generic function with db->xapian_db->allterms_begin()
as argument.
Finally, notmuch_database_get_all_tags is exported through
lib/notmuch.h
Signed-off-by: Jan Janak <jan@ryngle.com>
I configured my database.path with a trailing /, and after running notmuch
new every notmuch search would fail with error messages like this:
Error opening /inbox/cur/1258565257.000211.mbox:2,S: No such file or directory
The actual bug was in the filename normalization for storage in the
database. The database.path was removed from the full filename, but if
the database.path from the config file contained a trailing /, the
relative file name would retain an extra leading /... which made it look
like an absolute path after it was read out from the DB.
Signed-off-by: Bart Trojanowski <bart@jukie.net>
If an earlier exception occurred, then it's not unexpected for the
flush to fail as well. So in that case, we'll silently catch the
exception. Otherwise, make some noise about things going wrong at the
time of flush.
We only rarely need to actually open the database for writing, but we
always create a Xapian::WritableDatabase. This has the effect of
preventing searches and like whilst updating the index.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Carl Worth <cworth@cworth.org>
More fallout from _get_header now returning "" for missing headers.
The bug here is that we would no longer detect that a file is not an
email message and give up on it like we should.
And this time, I actually audited all callers to
notmuch_message_get_header, so hopefully we're done fixing this
bug over and over.
This eliminates a crash when a message (either corrupted or a non-mail
file that wasn't properly detected as not being mail) has no In-Reply-To
header, (and so few terms that trying to skip to the prefix of the
In-Reply-To terms actually brings us to the end of the termlist).
The message file header parsing code parses only enough of the file to
find the desired header fields, then it leaves the file open until the
next header parsing call or when the message is no longer in use. If a
large number of messages end up being active, this will quickly run
out of file descriptors.
Here, we add support to explicitly close the message file within a
message, (_notmuch_message_close) and call that from thread
construction code.
Signed-off-by: Keith Packard <keithp@keithp.com>
Edited-by: Carl Worth <cworth@cworth.org>:
Many portions of Keith's original patch have since been solved other
ways, (such as the code that changed the handling of the In-Reply-To
header). So the final version is clean enough that I think even Keith
would be happy to have his name on it.
This case was happening when a message had its own message ID in its
In-Reply-To header. The thread-resolution code would find the
partially constructed message, (with no thread ID yet), get garbage
from this function, and then march right along with that garbage.
With this commit, a self-cyclic message like this will now trigger an
internal error rather than marching along silienty. (And a subsequent
commit will remove the call to this function in this case.)
This function has only one caller, and that one caller was passing the
same value for both talloc_owner and the notmuch database. Dropping
the redundant argument simplifies the documentation of this function
considerably.
This reduces our reliance on open message_file objects, (so is a step
toward fixing the "too many open files" bug), but more importantly, it
means we don't load a self-referencing in-reply-to header, (since we
weed those out before adding any replyto terms to the database).
We now properly analyze the in-reply-to headers to create a proper
tree representing the actual thread and present the messages in this
correct thread order. Also, there's a new "depth:" value added to the
"message{" header so that clients can format the thread as desired,
(such as by indenting replies).
The existing notmuch_message_get_header is *almost* good enough for
this, except that we also need to remove the '<' and '>'
delimiters. We'll probably want to implement this function with
database storage in the future rather than loading the email message.
