Includes:
1. mode change read lock operation in every exported method that r/w the
underlying database;
2. returning `ErrDegradedMode` logical error if any exported method is
called in degraded (without a metabase) mode.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Core changes:
* avoid package-colliding variable naming
* avoid using pointers to IDs where unnecessary
* avoid using `idSDK` import alias pattern
* use `EncodeToString` for protocol string calculation and `String` for
printing
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
- Delete objects physically on tombstone's arrival;
- Store information about tombstones in the Graveyard;
- Clear Graveyard every epoch based on the information about TS in the
network.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Add offset element to the iterations over deleted objects (both the
Graveyard and the Garbage buckets).
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
It allows storing information about object in both ways at the same time:
1. Metabase should know if an object is covered by a tombstone (that is
not expired yet);
2. It should be possible to physically delete objects covered by a
tombstone immediately (mark with GC) but keep tombstone knowledge.
Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>
Make `DB.IterateOverGraveyard` to immediately return nil if GraveHandler
returns ErrInterruptIterator.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
Implement `DB.IterateOverGraveyard` method that iterates over all graves and
passes passes their descriptors (new type `Grave`) to handler (new type
`GraveHandler`). `Grave` currently have buried object address and garbage
flag.
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
