Avoid Timeline race condition
Summary: While I should fix the transactional stuff, that patch is going to be
tricky and transactions have some performance implications. This is a simple
fix which prevents the race.
Instead of having the data point at the event ID, have the event point at a
data ID. Insert the data first, then insert the event with the right data
pointer. This is super simple and prevents the race issue.
Test Plan:
- Ran the schema upgrade script, verified that the database was correctly upgraded. Was also prompted to stop daemons.
- Ran 'repository-launch-master', verified that the discovery daemons were able to discover new commits and insert events for them. Verified the committask daemon was consuming events and converting them into tasks.
- Verified new tasks looked correct in the database.
- Browsed web interface.
Reviewers: jungejason
CC: tuomaspelkonen
Differential Revision: 133