Christian Boos wrote: > There was some negative reactions at the time I proposed it for > integration into trunk, because some people didn't like the > `transaction` helper function I mixed in there (note in passing that by > using such a helper consistently for performing commit/rollback on SQL > transactions instead of relying on the gc for the eventual rollback, we > wouldn't have the occasional "current transaction is aborted" error).
FWIW, I rather liked the transaction() idea, but I would have
implemented it as a function decorator, and used an inner function for
the DB code (example from attachment.py):
def delete(self, db=None):
assert self.filename, 'Cannot delete non-existent attachment'
@as_transaction(self.env, db)
def execute(db):
cursor = db.cursor()
cursor.execute("DELETE FROM attachment WHERE type=%s "
"AND id=%s AND filename=%s",
(self.parent_realm, self.parent_id,
self.filename))
if os.path.isfile(self.path):
try:
os.unlink(self.path)
except OSError, e:
self.env.log.error('Failed to delete attachment '
'file %s: %s', self.path,
exception_to_unicode(e, traceback=True))
raise TracError(_('Could not delete attachment'))
self.env.log.info('Attachment removed: %s' % self.title)
for listener in AttachmentModule(self.env).change_listeners:
listener.attachment_deleted(self)
The as_transaction decorator would set up the database connection if
necessary, call the decorated function and commit or rollback if necessary.
This would also have the additional benefit that it becomes easy to move
to context managers once we drop support for Python 2.4, by replacing:
@as_transaction(self.env, db)
def execute(db):
with:
with transaction(self.env, db) as db:
Just my EUR 0.02.
-- Remy
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