In this commit, the bugs demonstrated in prior commits are fixed. In the
case where an session has persisted a CommittedUpdate and the tower is
being removed, the session will now replay that update on to the main
task pipeline so that it can be backed up using a different session.
This commit does a few things:
- First, it gives the sessionQueue access to the TowerClient task
pipeline so that it can replay backup tasks onto the pipeline on Stop.
- Given that the above is done, the ForceQuit functionality of the
sessionQueue and TowerClient can be removed.
- The bug demonstrated in a prior commit is now fixed due to the above
changes.
In preparation for an upcoming commit where multiple threads will have
access to the TowerClient sessionQueueSet, we turn it into a thread safe
struct.
This commit upgrades the wtclient package to make use of the new
`AddressIterator`. It does so by first creating new `Tower` and
`ClientSession` types. The new `Tower` type has an `AddressIterator`
instead of a list of addresses. The `ClientSession` type contains a
`Tower`.
In this commit, the new ListClientSession functional options and new
FetchSessionCommittedUpdates function are utilised in order to allow us
to completely remove the CommittedUpdates member from the ClientSession
struct.
This commit replaces the map-based CommittedUpdates field with a slice.
When reading from disk, these will already be sorted by bbolt, so the
client restore the updates as presented without needing to sort them
first.
Since the key in the map variant was the sequence number, we refactor
the CommittedUpdate struct to have a sequence number and an embedded
CommittedUpdateBody (which is equivalent to the old CommittedUpdate).
The database is then expected to populate the sequence number from the
key on disk.
Since the sequence number is now directly integrated in the
CommittedUpdate struct, this allow allows us to remove the now redundant
seqNum argument from CommitUpdate.
