The compaction_manager::stop_compaction() method internally walks the
list of tasks and compares each task's compacting_table (which is
compaction group view pointer) with the given one. In case this
stop_compaction() method is called via API for a specific table, the
method walks the list of tasks for every compaction group from the
table, thus resulting in nr_groups * nr_tasks complexity. Not terrible,
but not nice either.
The proposal is to pass filtering function into the inner
do_stop_ongoing_compactions() method. Some users will pass a simple
"return true" lambda, but those that need to stop compactions for a
specitif table (e.g. -- the API handler) will effectively walk the
list of tasks once comparing the given compaction group's schema with
the target table one (spoiler: eventually this place will also be
simplified not to mess with replica::table at all).
One ugliness with the change is the way "scope" for logging message is
collected. If all tasks belong to the same table, then "for table ..."
is printed in logs. With the change the scope is no longer known
instantly and is evaluated dynamically while walking the list of tasks.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#25846
d69a51f42a