Currently we use `(*bbolt.Bucket).Stats().KeyN` for estimating database
size. However, it iterates over all pages in bucket and thus heavily
depends on the bucket size. This commit replaces initial size estimation
with a single `os.Stat` call.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
If pre-existing blobovnicza is initialized, it's size should be updated
even if all buckets are in place.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
Make `syncFullnessCounter` to accept `bbolt.Tx` argument of Bolt
transaction within which counter should be synchronized. Pass
corresponding transaction during `Init`.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
There is a need to open Blobovnicza instances in read-only mode in some
cases.
Add `ReadOnly` option. Do not create dir path in RO. Open underlying BoltDB
instance with ReadOnly flag. Document thal all writing operations should not
be called in ro (otherwise BoltDB txs fail).
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
