This adds an extra option to allow setting the SQLite page cache size as a regular option.
Prior to this commit it was only possible to set the SQLite page cache size via environment variables.
The option to use environment variables is preserved, and as options from the environment variable are applied after the new setting, environment variables take precedence.
The default value for the new option is to use 1% of the system memory for the page cache. For the restore process, a connection per worker may be made which defaults to half the number of cores, so the maximum amount of memory is 1% * half the CPU cores.
This is just the upper limit, and SQLite may choose not to use all of it.
This fixes#6178
The option is turned into an enum with values True, False, ListIndexes
True and False are for compatibility with the existing backups.
ListIndexes is equivalent to True but don't handle block volumes.
This is to make more workable a strategy of full remote testing
after each backup.
When referencing virtual members in a constructor, the behavior may be
ill-defined as the overridden implementation may depend on uninitialized
instance members.
Since the TABLE_PREFIX, TABLEFORMAT, INSERTCOMMAND, and INSERTARGUMENTS
properties were only referenced in the Basiclist constructor, we can
remove the abstract keyword and provide the values as constructor
parameters.
While this does not affect any behavior, it more accurately describes
the accessibility. Since abstract classes can only be instantiated by
an instance of a derived type, the constructors should at most have
protected access.
Implemented better output for Restore.
Fixed a problem with errors during dispose, and a problem with selecting filesets that do not exist.
Fixed a bug with restore if a file existed with some correct data, a copy would be restored with partial data.
Added check to try to avoid excessive restores of the same files if a file in another version already exists.
