diff options
Diffstat (limited to 'Lib/mailbox.py')
| -rwxr-xr-x | Lib/mailbox.py | 99 |
1 files changed, 61 insertions, 38 deletions
diff --git a/Lib/mailbox.py b/Lib/mailbox.py index ed7c7d1..0843430 100755 --- a/Lib/mailbox.py +++ b/Lib/mailbox.py @@ -2,6 +2,12 @@ """Read/write support for Maildir, mbox, MH, Babyl, and MMDF mailboxes.""" +# Notes for authors of new mailbox subclasses: +# +# Remember to fsync() changes to disk before closing a modified file +# or returning from a flush() method. See functions _sync_flush() and +# _sync_close(). + import sys import os import time @@ -235,7 +241,7 @@ class Maildir(Mailbox): try: self._dump_message(message, tmp_file) finally: - tmp_file.close() + _sync_close(tmp_file) if isinstance(message, MaildirMessage): subdir = message.get_subdir() suffix = self.colon + message.get_info() @@ -246,7 +252,19 @@ class Maildir(Mailbox): suffix = '' uniq = os.path.basename(tmp_file.name).split(self.colon)[0] dest = os.path.join(self._path, subdir, uniq + suffix) - os.rename(tmp_file.name, dest) + try: + if hasattr(os, 'link'): + os.link(tmp_file.name, dest) + os.remove(tmp_file.name) + else: + os.rename(tmp_file.name, dest) + except OSError, e: + os.remove(tmp_file.name) + if e.errno == errno.EEXIST: + raise ExternalClashError('Name clash with existing message: %s' + % dest) + else: + raise if isinstance(message, MaildirMessage): os.utime(dest, (os.path.getatime(dest), message.get_date())) return uniq @@ -364,12 +382,14 @@ class Maildir(Mailbox): def get_folder(self, folder): """Return a Maildir instance for the named folder.""" - return Maildir(os.path.join(self._path, '.' + folder), create=False) + return Maildir(os.path.join(self._path, '.' + folder), + factory=self._factory, + create=False) def add_folder(self, folder): """Create a folder and return a Maildir instance representing it.""" path = os.path.join(self._path, '.' + folder) - result = Maildir(path) + result = Maildir(path, factory=self._factory) maildirfolder_path = os.path.join(path, 'maildirfolder') if not os.path.exists(maildirfolder_path): os.close(os.open(maildirfolder_path, os.O_CREAT | os.O_WRONLY)) @@ -420,12 +440,17 @@ class Maildir(Mailbox): except OSError, e: if e.errno == errno.ENOENT: Maildir._count += 1 - return open(path, 'wb+') + try: + return _create_carefully(path) + except OSError, e: + if e.errno != errno.EEXIST: + raise else: raise - else: - raise ExternalClashError('Name clash prevented file creation: %s' % - path) + + # Fall through to here if stat succeeded or open raised EEXIST. + raise ExternalClashError('Name clash prevented file creation: %s' % + path) def _refresh(self): """Update table of contents mapping.""" @@ -560,7 +585,8 @@ class _singlefileMailbox(Mailbox): new_file.close() os.remove(new_file.name) raise - new_file.close() + _sync_close(new_file) + # self._file is about to get replaced, so no need to sync. self._file.close() try: os.rename(new_file.name, self._path) @@ -575,7 +601,7 @@ class _singlefileMailbox(Mailbox): self._toc = new_toc self._pending = False if self._locked: - _lock_file(new_file, dotlock=False) + _lock_file(self._file, dotlock=False) def _pre_mailbox_hook(self, f): """Called before writing the mailbox to file f.""" @@ -594,7 +620,7 @@ class _singlefileMailbox(Mailbox): self.flush() if self._locked: self.unlock() - self._file.close() + self._file.close() # Sync has been done by self.flush() above. def _lookup(self, key=None): """Return (start, stop) or raise KeyError.""" @@ -784,7 +810,7 @@ class MH(Mailbox): if self._locked: _unlock_file(f) finally: - f.close() + _sync_close(f) return new_key def remove(self, key): @@ -831,7 +857,7 @@ class MH(Mailbox): if self._locked: _unlock_file(f) finally: - f.close() + _sync_close(f) def get_message(self, key): """Return a Message representation or raise a KeyError.""" @@ -918,7 +944,7 @@ class MH(Mailbox): """Unlock the mailbox if it is locked.""" if self._locked: _unlock_file(self._file) - self._file.close() + _sync_close(self._file) del self._file self._locked = False @@ -941,11 +967,13 @@ class MH(Mailbox): def get_folder(self, folder): """Return an MH instance for the named folder.""" - return MH(os.path.join(self._path, folder), create=False) + return MH(os.path.join(self._path, folder), + factory=self._factory, create=False) def add_folder(self, folder): """Create a folder and return an MH instance representing it.""" - return MH(os.path.join(self._path, folder)) + return MH(os.path.join(self._path, folder), + factory=self._factory) def remove_folder(self, folder): """Delete the named folder, which must be empty.""" @@ -1013,7 +1041,7 @@ class MH(Mailbox): else: f.write('\n') finally: - f.close() + _sync_close(f) def pack(self): """Re-name messages to eliminate numbering gaps. Invalidates keys.""" @@ -1023,27 +1051,13 @@ class MH(Mailbox): for key in self.iterkeys(): if key - 1 != prev: changes.append((key, prev + 1)) - f = open(os.path.join(self._path, str(key)), 'r+') - try: - if self._locked: - _lock_file(f) - try: - if hasattr(os, 'link'): - os.link(os.path.join(self._path, str(key)), - os.path.join(self._path, str(prev + 1))) - if sys.platform == 'os2emx': - # cannot unlink an open file on OS/2 - f.close() - os.unlink(os.path.join(self._path, str(key))) - else: - f.close() - os.rename(os.path.join(self._path, str(key)), - os.path.join(self._path, str(prev + 1))) - finally: - if self._locked: - _unlock_file(f) - finally: - f.close() + if hasattr(os, 'link'): + os.link(os.path.join(self._path, str(key)), + os.path.join(self._path, str(prev + 1))) + os.unlink(os.path.join(self._path, str(key))) + else: + os.rename(os.path.join(self._path, str(key)), + os.path.join(self._path, str(prev + 1))) prev += 1 self._next_key = prev + 1 if len(changes) == 0: @@ -1867,6 +1881,15 @@ def _create_temporary(path): socket.gethostname(), os.getpid())) +def _sync_flush(f): + """Ensure changes to file f are physically on disk.""" + f.flush() + os.fsync(f.fileno()) + +def _sync_close(f): + """Close file f, ensuring all changes are physically on disk.""" + _sync_flush(f) + f.close() ## Start: classes from the original module (for backward compatibility). |