in the case of imap stores, the failure is bound to the server config,
not just the store config.
that means that the storage of the failure state needs to be private to
the driver, accessible only through a function.
simply make the code symmetrical to the inverse case.
note that the result will be sort of awkward, as the folders under Path
(and thus the subfolders of Inbox) don't start with a dot, while the
subfolders of these folders do. this needs to be addressed separately.
when we run into Inbox while listing Path, check whether Inbox is being
listed anyway, and just skip it if so, instead of listing it right away
and resetting LIST_INBOX (and thus having a calling order dependency).
- the old meaning of -V[V] was moved to -D{n|N}, as these are really
debugging options.
- don't print the info messages by default; this can be re-enabled with
the -V switch, and is implied by most debug options (it was really
kind of stupid that verbose/debug operation disabled these).
- the sync algo/state debugging can be separately enabled with -Ds now.
propagating many messages from a fast store (typically maildir or a
local IMAP server) to a slow asynchronous store could cause gigabytes of
data being buffered. avoid this by throttling fetches if the target
context reports memory usage above a configurable limit.
REFMAIL: 9737edb14457c71af4ed156c1be0ae59@mpcjanssen.nl
don't retry dead Stores for every Channel.
this also introduces a state for transient errors (specifically, connect
failures), but this is currently unused.
a directory is no mailbox unless it contains a cur/ subdir.
but if that one is present, create new/ and tmp/ if they are missing.
this makes it possible to resume interrupted maildir creations.
the seznam.cz IMAP server seems very eager to send UIDNEXT responses
despite not supporting UIDPLUS. this doesn't appear to be a particularly
sensible combination, but it's valid nonetheless.
however, that means that we need to save the UIDNEXT value before we
start storing messages, lest imap_find_new_msgs() will simply overlook
them. we do that outside the driver, in an already present field - this
actually makes the main path more consistent with the journal recovery
path.
analysis by Tomas Tintera <trosos@seznam.cz>.
REFMAIL: 20141220215032.GA10115@kyvadlo.trosos.seznam.cz
... for windows fs compatibility.
the maildir-specific InfoDelimiter inherits the global FieldDelimiter
(which affects SyncState), based on the assumption that if the sync
state is on a windows FS, the mailboxes certainly will be as well, while
the inverse is not necessarily true (when running on unix, anyway).
REFMAIL: <CA+m_8J1ynqAjHRJagvKt9sb31yz047Q7NH-ODRmHOKyfru8vtA@mail.gmail.com>
memcmp() is unfortunately not guaranteed to read forward byte-by-byte,
which means that the clever use as a strncmp() without the pointless
strlen()s is not permitted, and can actually misbehave with
SSE-optimized string functions.
so implement proper equals() and starts_with() functions. as a bonus,
the calls are less cryptic.
the highest assigned UID must always be at least as high as the highest
actually found UID, as otherwise we'd hand out duplicate UIDs at some
point. also, getting into such a state in the first place indicates some
potentially serious trouble, or at least external interference (e.g.,
moving/copying a message from another folder without giving it a
pristine filename).
REFMAIL: 20140626211831.GA11590@sie.protva.ru
if something managed to make the maildir .uidvalidity files big enough
(possible only by appending garbage or scrambling them alltogether), we
would overflow the read buffer by one when appending the terminating
null.
this is not expected to have any real-world impact.
found by coverity.
we would see the recent timestamp of the creation and conclude that
something is going on, so we'd wait. this is obviously nonsense.
as we know that a freshly created mailbox is empty, simply skip the
message scan alltogether.
time_t may be long long. to keep the sprintf format strings simple, just
downcast - this is not going to be a problem for the next 30 years, and
until then long will be 64-bit everywhere anyway.
suggested 3.5 years ago by Antoine Reilles <tonio@NetBSD.org>.
this fixes two possible failure scenarios:
- if the journal is committed but the mails are not, the missing files
would be erroneously interpreted as deletions which would be
propagated
- less seriously, if the mail files' meta data was committed but the
file contents were not, we would end up with empty files, which would
have to be re-fetched "behind mbsync's back" (just deleting the files
would not work - see above)
pass DB_TRUNCATE when creating databases. otherwise bdb will complain
about the empty file we pass it (we have to create it upfront to
implement our locking).
files may be renamed (due to new -> cur transition or flag changes),
which may lead to two effects if ignored:
- we see both the old and the new name, so we report a spurious
duplicate UID
- we see neither name, so we report a spurious deletion
as countermeasure, record and compare directory modification times. upon
mismatch, we just start over - as usual.
don't try to unlock and close databases and files - this will happen a
moment later anyway, through cancelation or re-selection.
ironically, this plugs a memory leak, because an open main database is
used as a signal to close a temporary db in maildir_scan().
instead of SEARCHing every single message (which is slow and happens to
be unreliabe with M$ Exchange 2010), just FETCH the new messages from
the mailbox - the ones we just appended will be amongst them.
- introduce sys_error() and use it instead of perror() and
error(strerror()) in all expected error conditions
- perror() is used only for "something's really wrong with the system"
kind of errors
- file names, etc. are quoted if they are not validated yet, so e.g. an
empty string becomes immediately obvious
- improve and unify language
- add missing newlines
synchronous error codes which are passed through callbacks aren't a
particularly good idea, after all: latest when the callback does stuff
which does not concern the caller, the return code becomes ambiguous.
instead, protect the sync_vars object with a refcount when invoking
driver functions from loops, as the callbacks they call could invalidate
the object and we would have no way of knowing that the loop should be
aborted prematurely. the upcoming async imap driver will also need a
refcount to protect the cancelation marker of the imap socket dispatcher
loop.
that way we don't have to piggy-back (possibly asynchronous) fatal
errors to particular commands.
internally, the drivers still use synchronous return values as well,
so they don't try to access the invalidated store after calling back.
imap may very well store messages with LF line endings. only RFC2822
requires CRLF.
consequently, preserve the line endings as much as possible unless the
mailbox format does not support it (this would be the case for unix mbox
- i actually have no idea about maildir).
