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.
With this commit we fix a few occurrences of loop variables being
accessed in closures.
While we touch the code, we also migrate it to using the require
library.
In this commit, a new tower client db function is added that can be used
to fetch all the committed updates for a given session ID. This is done
in preparation for an upcoming commit where the CommittedUpdates will be
removed from the ClientSession struct.
In this commit, we start making use of the new ListClientSession
functional options added in the previous commit. We use the functional
options in order to calculate the max commit heights per channel on the
construction of the tower client. We also use the options to count the
total number of acked and committed updates. With this commit, we are
also able to completely remove the AckedUpdates member of the
ClientSession since it is no longer used anywhere in the code.
This commit adds functional options to the ListClientSessions call that
can be used to perform a variety of extra operations during the DB
query. These functional options are not yet used in this commit.
In this commit, the functions used to fetch candidate sessions and
towers on creation of the watchtower Client are changed to make use of
the more efficient lookup functions. Previously, all sessions were
listed from the DB and then these were used to collect the active
towers which in certain situations lead to some users getting the
"tower not found" error on start up. With this commit, we instead first
list all Towers in the DB and then we fetch the sessions for each of
those towers.
In this commit, the towerID-to-sessionID index added in the previous
commit is put to use in order to make session lookup more efficient in
certain places. In the process, 2 TODO's are also removed from the code.
This commit adds a new towerID-to-sessionID index to the wtclient DB.
The commit also contains the necessary migration required in order to
build the index for an existing client.
This index will greatly improve the lookup of sessions for a given tower
ID.
Before creating a new session, first check that the TowerID that the
ClientSession is referencing refers to an existing tower. This is done
to prevent the situation where RemoveTower is called right before
CreateClientSession is called which would, before this commit, lead to
the session being created with a tower ID that does not refer to any
existing tower.
To avoid running a channel DB that was successfully migrated to another
system by accident, we check if there is a tombstone marker before we
open the DB for use.
We'll need to know whether a database was migrated to the latest version
in our upcoming data migration tool. To be able to determine the current
version of a DB and the total number of migrations in existence, we need
to export some of the functions in channeldb.
We also add some helper functions for adding tombstone and other markers
to a database.
