// Attempt partial rollback. Implementation sketch: walk through
// previous mossStore snapshots until we reach to a point at or before
// the wanted rollbackSeq. If found, revert to that prevous snapshot.
func (t *BleveDest) partialRollbackLOCKED(partition string,
rollbackSeq uint64) (bool, bool, error) {
if t.bindex == nil {
return false, false, nil
}
_, kvstore, err := t.bindex.Advanced()
if err != nil {
return false, false, err
}
llsh, ok := kvstore.(LowerLevelStoreHolder)
if !ok {
return false, false, fmt.Errorf("kvstore not a llsh, kvstore: %#v", kvstore)
}
lls := llsh.LowerLevelStore()
if lls == nil {
return false, false, fmt.Errorf("lls nil")
}
msah, ok := lls.(MossStoreActualHolder)
if !ok {
return false, false, fmt.Errorf("llsh not a msah, llsh: %#v", llsh)
}
store := msah.Actual()
if store == nil {
return false, false, nil // No moss store, so no partial rollback.
}
store.AddRef()
defer store.Close()
// TODO: Handle non-upsidedown bleve index types some day.
seqMaxKey := upsidedown.NewInternalRow([]byte(partition), nil).Key()
totSnapshotsExamined := 0
defer func() {
log.Printf("pindex_bleve_rollback: path: %s, totSnapshotsExamined: %d",
t.path, totSnapshotsExamined)
}()
var ss, ssPrev moss.Snapshot
ss, err = store.Snapshot()
for err == nil && ss != nil {
totSnapshotsExamined++
var tryRevert bool
tryRevert, err = snapshotAtOrBeforeSeq(t.path, ss, seqMaxKey, rollbackSeq)
if err != nil {
ss.Close()
return false, false, err
}
if tryRevert {
log.Printf("pindex_bleve_rollback: trying revert, path: %s", t.path)
// Close the bleve index, but keep our ref-counts on the
// underlying store and snapshot until after the revert.
t.closeLOCKED()
err = store.SnapshotRevert(ss)
ss.Close()
return true, err == nil, err
}
ssPrev, err = store.SnapshotPrevious(ss)
ss.Close()
ss = ssPrev
}
return false, false, err
}
