#9559: Append data to single-file mailbox files if messages are only added
If messages were only added, a new file is no longer created and
renamed over the old file when flush() is called on an mbox, MMDF or
Babyl mailbox.
diff --git a/Lib/mailbox.py b/Lib/mailbox.py
index 6a69819..ecd9f61 100644
--- a/Lib/mailbox.py
+++ b/Lib/mailbox.py
@@ -561,16 +561,19 @@
self._file = f
self._toc = None
self._next_key = 0
- self._pending = False # No changes require rewriting the file.
+ self._pending = False # No changes require rewriting the file.
+ self._pending_sync = False # No need to sync the file
self._locked = False
- self._file_length = None # Used to record mailbox size
+ self._file_length = None # Used to record mailbox size
def add(self, message):
"""Add message and return assigned key."""
self._lookup()
self._toc[self._next_key] = self._append_message(message)
self._next_key += 1
- self._pending = True
+ # _append_message appends the message to the mailbox file. We
+ # don't need a full rewrite + rename, sync is enough.
+ self._pending_sync = True
return self._next_key - 1
def remove(self, key):
@@ -616,6 +619,11 @@
def flush(self):
"""Write any pending changes to disk."""
if not self._pending:
+ if self._pending_sync:
+ # Messages have only been added, so syncing the file
+ # is enough.
+ _sync_flush(self._file)
+ self._pending_sync = False
return
# In order to be writing anything out at all, self._toc must
@@ -669,6 +677,7 @@
self._file = open(self._path, 'rb+')
self._toc = new_toc
self._pending = False
+ self._pending_sync = False
if self._locked:
_lock_file(self._file, dotlock=False)
@@ -705,6 +714,9 @@
"""Append message to mailbox and return (start, stop) offsets."""
self._file.seek(0, 2)
before = self._file.tell()
+ if len(self._toc) == 0:
+ # This is the first message
+ self._pre_mailbox_hook(self._file)
try:
self._pre_message_hook(self._file)
offsets = self._install_message(message)