diff options
| -rwxr-xr-x | archivemail.py | 215 |
1 files changed, 82 insertions, 133 deletions
diff --git a/archivemail.py b/archivemail.py index 45b160d..fbbbc28 100755 --- a/archivemail.py +++ b/archivemail.py @@ -137,9 +137,8 @@ class Stats: class StaleFiles: """Class to keep track of files to be deleted on abnormal exit""" - archive = None # tempfile for messages to be archived dotlock_lock = None # original_mailbox.lock - retain = None # tempfile for messages to be retained + temp_mboxes = [] # temporary retain and archive mboxes temp_dir = None # our tempfile directory container def clean(self): @@ -150,17 +149,11 @@ class StaleFiles: os.remove(self.dotlock_lock) self.dotlock_lock = None except (IOError, OSError): pass - if self.retain: - vprint("removing stale retain file '%s'" % self.retain) + while self.temp_mboxes: + mbox = self.temp_mboxes.pop() + vprint("removing stale temporary mbox '%s'" % mbox) try: - os.remove(self.retain) - self.retain = None - except (IOError, OSError): pass - if self.archive: - vprint("removing stale archive file '%s'" % self.archive) - try: - os.remove(self.archive) - self.archive = None + os.remove(mbox) except (IOError, OSError): pass if self.temp_dir: vprint("removing stale tempfile directory '%s'" % self.temp_dir) @@ -318,9 +311,8 @@ class Options: class Mbox(mailbox.UnixMailbox): - """A mostly-read-only mbox with locking. Subclasses the mailbox.UnixMailbox - class. - """ + """A mostly-read-only mbox with locking. The mbox content can only be + modified by overwriting the entire underlying file.""" def __init__(self, path): """Constructor for opening an existing 'mbox' mailbox. @@ -450,6 +442,31 @@ class Mbox(mailbox.UnixMailbox): """Return the current size of the mbox file""" return os.path.getsize(self.mbox_file_name) + def overwrite_with(self, mbox_filename): + """Overwrite the mbox content with the content of the given mbox file.""" + fin = open(mbox_filename, "r") + self.mbox_file.seek(0) + shutil.copyfileobj(fin, self.mbox_file) + self.mbox_file.truncate() + + +class ArchiveMbox: + """Simple append-only access to the archive mbox. Entirely content-agnostic.""" + + def __init__(self, path): + fd = safe_open(path) + self.mbox_file = os.fdopen(fd, "a") + + def append(self, filename): + """Append the content of the given file to the mbox.""" + fin = open(filename, "r") + shutil.copyfileobj(fin, self.mbox_file) + fin.close() + + def close(self): + """Close the mbox file.""" + self.mbox_file.close() + class TempMbox: """An write-only temporary mbox. No locking methods.""" @@ -458,6 +475,7 @@ class TempMbox: """Creates a temporary mbox file.""" fd, filename = tempfile.mkstemp(prefix=prefix) self.mbox_file_name = filename + _stale.temp_mboxes.append(filename) self.mbox_file = os.fdopen(fd, "w") # an empty gzip file is not really empty (it contains the gzip header # and trailer), so we need to track manually if this mbox is empty @@ -512,110 +530,22 @@ class TempMbox: self.mbox_file.close() def remove(self): - """Close and delete the 'mbox' mailbox file""" - file_name = self.mbox_file_name - self.close() - vprint("removing file '%s'" % self.mbox_file_name) - os.remove(file_name) - - -class RetainMbox(TempMbox): - """Class for holding messages that will be retained from the original - mailbox (ie. the messages are not considered 'old'). Extends the 'Mbox' - class. This 'mbox' file starts off as a temporary file but will eventually - overwrite the original mailbox if everything is OK. - - """ - - def __init__(self, final_mbox_file): - """Constructor - create a temporary file for the mailbox. - - Arguments: - final_mbox_file -- file object of the original mailbox that this mailbox - will replace when we call finalise() - - """ - assert(final_mbox_file) - TempMbox.__init__(self, prefix="retain") - _stale.retain = self.mbox_file_name - vprint("opened temporary retain file '%s'" % self.mbox_file_name) - self.__final_mbox_file = final_mbox_file - - def finalise(self): - """Overwrite the original mailbox with this temporary mailbox.""" - assert(self.__final_mbox_file) - new_size = self.mbox_file.tell() - old_size = self.__final_mbox_file.tell() - if new_size == old_size: - vprint("no pending changes to mbox '%s'" % \ - self.__final_mbox_file.name) - else: - self.close() - self.mbox_file = open(self.mbox_file_name, "r") - vprint("overwriting mbox '%s' with temporary mbox '%s'" % \ - (self.__final_mbox_file.name, self.mbox_file_name)) - self.__final_mbox_file.seek(0) - shutil.copyfileobj(self.mbox_file, self.__final_mbox_file) - self.__final_mbox_file.truncate() - self.remove() - - def remove(self): - """Close and delete this temporary mailbox.""" - TempMbox.remove(self) - _stale.retain = None - + """Delete the temporary mbox file.""" + os.remove(self.mbox_file_name) + _stale.temp_mboxes.remove(self.mbox_file_name) -class ArchiveMbox(TempMbox): - """Class for holding messages that will be archived from the original - mailbox (ie. the messages that are considered 'old'). Extends the 'Mbox' - class. This 'mbox' file starts off as a temporary file, and will eventually - be appended to the original archive mailbox if everything is OK. - - """ - __final_name = None +class CompressedTempMbox(TempMbox): + """A compressed version of a TempMbox.""" - def __init__(self, final_name): - """Constructor -- create a temporary archive. - - Arguments: - final_name -- the final name for this archive mailbox. The temporary - archive will be appended to this file when we call - finalise() - """ - assert(final_name) - if options.no_compress: - TempMbox.__init__(self, prefix="archive") - else: - TempMbox.__init__(self, prefix="archive.gz") - self.mbox_file.close() - self.mbox_file = gzip.GzipFile(self.mbox_file_name, "w") - _stale.archive = self.mbox_file_name - self.__final_name = final_name - - def finalise(self): - """Append the temporary archive to the final archive, and delete it - afterwards.""" - assert(self.__final_name) - self.close() - if not self.empty: - self.mbox_file = open(self.mbox_file_name, "r") - final_name = self.__final_name - if not options.no_compress: - final_name = final_name + ".gz" - vprint("writing back '%s' to '%s'" % (self.mbox_file_name, final_name)) - fd = safe_open(final_name) - final_archive = os.fdopen(fd, "a") - shutil.copyfileobj(self.mbox_file, final_archive) - final_archive.close() - self.remove() + def __init__(self, prefix=tempfile.template): + TempMbox.__init__(self, prefix) + self.raw_file = self.mbox_file + self.mbox_file = gzip.GzipFile(mode="a", fileobj=self.mbox_file) - def remove(self): - """Delete the 'mbox' mailbox file""" - # Can't call TempMbox.remove here, because it would close the mbox - # a second time. - vprint("removing file '%s'" % self.mbox_file_name) - os.remove(self.mbox_file_name) - _stale.archive = None + def close(self): + """Finish gzip file and close it.""" + self.mbox_file.close() # close GzipFile, writing gzip trailer + self.raw_file.close() class IdentityCache: @@ -1166,11 +1096,8 @@ def _archive_mbox(mailbox_name, final_archive_name): if options.dry_run or options.copy_old_mail: retain = None else: - retain = RetainMbox(original.mbox_file) - if options.dry_run or options.delete_old_mail: - archive = None - else: - archive = ArchiveMbox(final_archive_name) + retain = TempMbox(prefix="retain") + archive = prepare_temp_archive() original.lock() msg = original.next() @@ -1199,10 +1126,17 @@ def _archive_mbox(mailbox_name, final_archive_name): if original.starting_size != original.get_size(): unexpected_error("the mailbox '%s' changed size during reading!" % \ mailbox_name) - if archive: - archive.finalise() + commit_archive(archive, final_archive_name) if retain: - retain.finalise() + pending_changes = original.mbox_file.tell() != retain.mbox_file.tell() + retain.close() + if pending_changes: + vprint("overwriting mbox '%s' with temporary mbox '%s'" % \ + (original.mbox_file_name, retain.mbox_file_name)) + original.overwrite_with(retain.mbox_file_name) + else: + vprint("no changes to mbox '%s'" % original.mbox_file_name) + retain.remove() original.unlock() original.close() original.reset_timestamps() @@ -1224,12 +1158,8 @@ def _archive_dir(mailbox_name, final_archive_name, type): original = mailbox.MHMailbox(mailbox_name) else: unexpected_error("unknown type: %s" % type) - cache = IdentityCache(mailbox_name) - if options.dry_run or options.delete_old_mail: - archive = None - else: - archive = ArchiveMbox(final_archive_name) + archive = prepare_temp_archive() for msg in original: if not msg: @@ -1255,8 +1185,7 @@ def _archive_dir(mailbox_name, final_archive_name, type): else: vprint("decision: retain message") vprint("finished reading messages") - if archive: - archive.finalise() + commit_archive(archive, final_archive_name) for file_name in delete_queue: vprint("removing original message: '%s'" % file_name) try: os.remove(file_name) @@ -1349,7 +1278,7 @@ def _archive_imap(mailbox_name, final_archive_name): if not options.dry_run: if not options.delete_old_mail: - archive = ArchiveMbox(final_archive_name) + archive = prepare_temp_archive() vprint("fetching messages...") for msn in message_list: # Fetching message flags and body together always finds \Seen @@ -1368,7 +1297,7 @@ def _archive_imap(mailbox_name, final_archive_name): if options.warn_duplicates: cache.warn_if_dupe(msg) archive.write(msg) - archive.finalise() + commit_archive(archive, final_archive_name) if not options.copy_old_mail: vprint("Deleting %s messages" % len(message_list)) # do not delete more than a certain number of messages at a time, @@ -1590,6 +1519,26 @@ def clean_up_signal(signal_number, stack_frame): # at this stage unexpected_error("received signal %s" % signal_number) +def prepare_temp_archive(): + """Create temporary archive mbox.""" + if options.dry_run or options.delete_old_mail: + return None + if options.no_compress: + return TempMbox() + else: + return CompressedTempMbox() + +def commit_archive(archive, final_archive_name): + """Finalize temporary archive and write it to its final destination.""" + if not options.no_compress: + final_archive_name = final_archive_name + '.gz' + if archive: + archive.close() + if not archive.empty: + final_archive = ArchiveMbox(final_archive_name) + final_archive.append(archive.mbox_file_name) + final_archive.close() + archive.remove() def make_archive_name(mailbox_name): """Derive archive name and (relative) path from the mailbox name.""" |