diff options
Diffstat (limited to 'Lib/mailbox.py')
| -rw-r--r-- | Lib/mailbox.py | 111 |
1 files changed, 82 insertions, 29 deletions
diff --git a/Lib/mailbox.py b/Lib/mailbox.py index 8b18010e20..0efd7434fe 100644 --- a/Lib/mailbox.py +++ b/Lib/mailbox.py @@ -234,23 +234,33 @@ class Maildir(Mailbox): def __init__(self, dirname, factory=rfc822.Message, create=True): """Initialize a Maildir instance.""" Mailbox.__init__(self, dirname, factory, create) + self._paths = { + 'tmp': os.path.join(self._path, 'tmp'), + 'new': os.path.join(self._path, 'new'), + 'cur': os.path.join(self._path, 'cur'), + } if not os.path.exists(self._path): if create: os.mkdir(self._path, 0700) - os.mkdir(os.path.join(self._path, 'tmp'), 0700) - os.mkdir(os.path.join(self._path, 'new'), 0700) - os.mkdir(os.path.join(self._path, 'cur'), 0700) + for path in self._paths.values(): + os.mkdir(path, 0o700) else: raise NoSuchMailboxError(self._path) self._toc = {} + self._toc_mtimes = {'cur': 0, 'new': 0} + self._last_read = 0 # Records last time we read cur/new + self._skewfactor = 0.1 # Adjust if os/fs clocks are skewing def add(self, message): """Add message and return assigned key.""" tmp_file = self._create_tmp() try: self._dump_message(message, tmp_file) - finally: - _sync_close(tmp_file) + except BaseException: + tmp_file.close() + os.remove(tmp_file.name) + raise + _sync_close(tmp_file) if isinstance(message, MaildirMessage): subdir = message.get_subdir() suffix = self.colon + message.get_info() @@ -369,7 +379,9 @@ class Maildir(Mailbox): def flush(self): """Write any pending changes to disk.""" - return # Maildir changes are always written immediately. + # Maildir changes are always written immediately, so there's nothing + # to do. + pass def lock(self): """Lock the mailbox.""" @@ -467,15 +479,39 @@ class Maildir(Mailbox): def _refresh(self): """Update table of contents mapping.""" + # If it has been less than two seconds since the last _refresh() call, + # we have to unconditionally re-read the mailbox just in case it has + # been modified, because os.path.mtime() has a 2 sec resolution in the + # most common worst case (FAT) and a 1 sec resolution typically. This + # results in a few unnecessary re-reads when _refresh() is called + # multiple times in that interval, but once the clock ticks over, we + # will only re-read as needed. Because the filesystem might be being + # served by an independent system with its own clock, we record and + # compare with the mtimes from the filesystem. Because the other + # system's clock might be skewing relative to our clock, we add an + # extra delta to our wait. The default is one tenth second, but is an + # instance variable and so can be adjusted if dealing with a + # particularly skewed or irregular system. + if time.time() - self._last_read > 2 + self._skewfactor: + refresh = False + for subdir in self._toc_mtimes: + mtime = os.path.getmtime(self._paths[subdir]) + if mtime > self._toc_mtimes[subdir]: + refresh = True + self._toc_mtimes[subdir] = mtime + if not refresh: + return + # Refresh toc self._toc = {} - for subdir in ('new', 'cur'): - subdir_path = os.path.join(self._path, subdir) - for entry in os.listdir(subdir_path): - p = os.path.join(subdir_path, entry) + for subdir in self._toc_mtimes: + path = self._paths[subdir] + for entry in os.listdir(path): + p = os.path.join(path, entry) if os.path.isdir(p): continue uniq = entry.split(self.colon)[0] self._toc[uniq] = os.path.join(subdir, entry) + self._last_read = time.time() def _lookup(self, key): """Use TOC to return subpath for given key, or raise a KeyError.""" @@ -518,7 +554,7 @@ class _singlefileMailbox(Mailbox): f = open(self._path, 'wb+') else: raise NoSuchMailboxError(self._path) - elif e.errno == errno.EACCES: + elif e.errno in (errno.EACCES, errno.EROFS): f = open(self._path, 'rb') else: raise @@ -667,9 +703,14 @@ class _singlefileMailbox(Mailbox): def _append_message(self, message): """Append message to mailbox and return (start, stop) offsets.""" self._file.seek(0, 2) - self._pre_message_hook(self._file) - offsets = self._install_message(message) - self._post_message_hook(self._file) + before = self._file.tell() + try: + self._pre_message_hook(self._file) + offsets = self._install_message(message) + self._post_message_hook(self._file) + except BaseException: + self._file.truncate(before) + raise self._file.flush() self._file_length = self._file.tell() # Record current length of mailbox return offsets @@ -835,18 +876,29 @@ class MH(Mailbox): new_key = max(keys) + 1 new_path = os.path.join(self._path, str(new_key)) f = _create_carefully(new_path) + closed = False try: if self._locked: _lock_file(f) try: - self._dump_message(message, f) + try: + self._dump_message(message, f) + except BaseException: + # Unlock and close so it can be deleted on Windows + if self._locked: + _unlock_file(f) + _sync_close(f) + closed = True + os.remove(new_path) + raise if isinstance(message, MHMessage): self._dump_sequences(message, new_key) finally: if self._locked: _unlock_file(f) finally: - _sync_close(f) + if not closed: + _sync_close(f) return new_key def remove(self, key): @@ -859,17 +911,9 @@ class MH(Mailbox): raise KeyError('No message with key: %s' % key) else: raise - try: - if self._locked: - _lock_file(f) - try: - f.close() - os.remove(os.path.join(self._path, str(key))) - finally: - if self._locked: - _unlock_file(f) - finally: + else: f.close() + os.remove(path) def __setitem__(self, key, message): """Replace the keyed message; raise KeyError if it doesn't exist.""" @@ -1808,7 +1852,10 @@ class _ProxyFile: def close(self): """Close the file.""" - del self._file + if hasattr(self, '_file'): + if hasattr(self._file, 'close'): + self._file.close() + del self._file def _read(self, size, read_method): """Read size bytes using read_method.""" @@ -1852,6 +1899,12 @@ class _PartialFile(_ProxyFile): size = remaining return _ProxyFile._read(self, size, read_method) + def close(self): + # do *not* close the underlying file object for partial files, + # since it's global to the mailbox object + if hasattr(self, '_file'): + del self._file + def _lock_file(f, dotlock=True): """Lock file f using lockf and dot locking.""" @@ -1861,7 +1914,7 @@ def _lock_file(f, dotlock=True): try: fcntl.lockf(f, fcntl.LOCK_EX | fcntl.LOCK_NB) except IOError, e: - if e.errno in (errno.EAGAIN, errno.EACCES): + if e.errno in (errno.EAGAIN, errno.EACCES, errno.EROFS): raise ExternalClashError('lockf: lock unavailable: %s' % f.name) else: @@ -1871,7 +1924,7 @@ def _lock_file(f, dotlock=True): pre_lock = _create_temporary(f.name + '.lock') pre_lock.close() except IOError, e: - if e.errno == errno.EACCES: + if e.errno in (errno.EACCES, errno.EROFS): return # Without write access, just skip dotlocking. else: raise |