Added methods needed to retain data based on a byte limitation rather than time. Limitation is only applied if the flag is set (defaults to 0). Both blocks that are older than the retention period and the blocks that make the size of the storage too large are removed.
2 new metrics for keeping track of the size of the local storage folder and the amount of times data has been deleted because the size restriction was exceeded.
Signed-off-by: Mark Knapp <mknapp@hudson-trading.com>
Blocks are half-open intervals [a, b), while all other intervals
(chunks, head, ...) are closed intervals [a, b].
Make that distinction explicit by defining `OverlapsClosedInterval()`
methods for blocks and chunks, and using them in place of the more
generic `intervalOverlap()` function.
This change also fixes `db.Querier()` and `db.Delete()`, which could
previously return one extraneous block at the end of the specified
interval.
Signed-off-by: Benoît Knecht <benoit.knecht@fsfe.org>
