Some classes had virtual methods, but were missing a virtual
destructor.
Technically, every unit test that inherits from the Beast test suite
would get flagged by `-Wnon-virtual-dtor` but I did not think it would
be a great idea to go sprinkle a virtual destructor for every Ripple
test suite.
The DatabaseImp has threads that asynchronously call JobQueue to
perform database reads. Formerly these threads had the same
lifespan as Database, which was until the end-of-life of
ApplicationImp. During shutdown these threads could call JobQueue
after JobQueue had already stopped. Or, even worse, occasionally
call JobQueue after JobQueue's destructor had run.
To avoid these shutdown conditions, Database is made a Stoppable,
with JobQueue as its parent. When Database stops, it shuts down
its asynchronous read threads. This prevents Database from
accessing JobQueue after JobQueue has stopped, but allows
Database to perform stores for the remainder of shutdown.
During development it was noted that the Database::close()
method was never called. So that method is removed from Database
and all derived classes.
Stoppable is also adjusted so it can be constructed using either
a char const* or a std::string.
For those files touched for other reasons, unneeded #includes
are removed.
* Add Backend::verify API for doing consistency checks
* Add Database::close so caller can catch exceptions
* Improved Timing test for NodeStore creates a simulated workload
Makes rippled configurable to support deletion of all data in its key-value
store (nodestore) and ledger and transaction SQLite databases based on
validated ledger sequence numbers. All records from a specified ledger
and forward shall remain available in the key-value store and SQLite, and
all data prior to that specific ledger may be deleted.
Additionally, the administrator may require that an RPC command be
executed to enable deletion. This is to align data deletion with local
policy.
