This is the simplest case as we can just cut each range like we already do,
then concat the results.
We still allow for the full design in the database and cutter, but error out if transitions
is ever anything but hard cuts or if it's a full cut.
We also update the restreamer to allow accepting ranges, however for usability we still allow
the old "just one start and end" args.
Note this changes the thrimshim API to give and take the new "video_ranges" and "video_transitions" columns.
This allows manual uploads to work without needing to fill all the edit fields
with junk.
We also set a constraint on uploader asserting that any videos from claimed onwards have a known uploader.
Again, an exception is made for DONE to allow manual uploads.
This should help prevent changing state to EDITED with any of these fields unset,
which would blow up the cutter.
We also fix up upload_location, which was set up as a sheet input (NOT NULL DEFAULT ''),
and add a similar constraint saying any DONE columns must have non-NULL video link.
All our usage was of a single query anyway, so autocommit is easier to handle.
You can still opt into a longer transaction using the transaction() helper.
This code manages the database connections, setting their isolation level correctly
and ensuring the idempotent schema is applied before they're used.
Applying the schema on startup means we don't need to deal with the database's state,
setting it up before running, running migrations etc. However, it does put constraints on
the changes we can safely make.
Our use of seralizable isolation means that all transactions can be treated as fully
independent - the server must behave as though they'd been run seperately in some valid order.
This will give us the least surprising results when multiple connections try to modify the same
data, though we'll need to deal with occasional transaction commit failures due to conficts.
Mike Lang
Christopher Usher
Mike Lang