Since ComponentBuildTrace(s) get created with db_session.commit() call,
is is not possible to commit more items in bulk if they already have been flushed.
Current unit-tests' setup can be significantly sped up if items can be quickly
flushed on the fly and bulk-commited only once at the end. Moreover in general it
seems more appropriate/safer to handle this in before_flush as any implicit
or accidental flush could cause new build traces not to be created at all. As flush
is implicitly called before every commit anyway, this change shouldn't pose any harm.
In MBS, there are two cases to send a message when a module build moves
to a new state. One is to create a new module build, with
ModuleBuild.create particularly, when user submit a module build.
Another one is to transition a module build to a new state with
ModuleBuild.transition. This commit handles these two cases in a little
different ways.
For the former, existing code is refactored by moving the publish call
outside ModuleBuild.create.
For the latter, message is sent in a hook of SQLAlchemy ORM event
after_commit rather than immediately inside the ModuleBuild.transition.
Both of these changes ensure the message is sent after the changes are
committed into database successfully. Then, the backend can have
confidence that the database has the module build data when receive a
message.
Signed-off-by: Chenxiong Qi <cqi@redhat.com>
This also includes `from __future__ import absolute_import`
in every file so that the imports are consistent in Python 2 and 3.
The Python 2 tests fail without this.
