// snapshotAtOrBeforeSeq returns true if the snapshot represents a seq
// number at or before the given seq number.
func snapshotAtOrBeforeSeq(path string, ss moss.Snapshot,
seqMaxKey []byte, seqMaxWant uint64) (bool, error) {
// Equivalent of bleve.Index.GetInternal(seqMaxKey).
v, err := ss.Get(seqMaxKey, moss.ReadOptions{})
if err != nil {
return false, err
}
if v == nil {
return false, nil
}
if len(v) != 8 {
return false, fmt.Errorf("wrong len seqMaxKey: %s, v: %s", seqMaxKey, v)
}
seqMaxCurr := binary.BigEndian.Uint64(v[0:8])
log.Printf("pindex_bleve_rollback: examining snapshot, path: %s,"+
" seqMaxKey: %s, seqMaxCurr: %d, seqMaxWant: %d",
path, seqMaxKey, seqMaxCurr, seqMaxWant)
return seqMaxCurr <= seqMaxWant, nil
}
// update() mutates this lower level store with latest data from the
// given higher level moss.Snapshot and returns a new moss.Snapshot
// that the higher level can use which represents this lower level
// store.
func (s *llStore) update(ssHigher moss.Snapshot, maxBatchSize uint64) (
ssLower moss.Snapshot, err error) {
if ssHigher != nil {
iter, err := ssHigher.StartIterator(nil, nil, moss.IteratorOptions{
IncludeDeletions: true,
SkipLowerLevel: true,
})
if err != nil {
return nil, err
}
defer func() {
err = iter.Close()
if err != nil {
s.logf("llStore iter.Close err: %v", err)
}
}()
kvWriter, err := s.kvStore.Writer()
if err != nil {
return nil, err
}
defer func() {
err = kvWriter.Close()
if err != nil {
s.logf("llStore kvWriter.Close err: %v", err)
}
}()
batch := kvWriter.NewBatch()
defer func() {
if batch != nil {
err = batch.Close()
if err != nil {
s.logf("llStore batch.Close err: %v", err)
}
}
}()
var readOptions moss.ReadOptions
i := uint64(0)
for {
if i%1000000 == 0 {
s.logf("llStore.update, i: %d", i)
}
ex, key, val, err := iter.CurrentEx()
if err == moss.ErrIteratorDone {
break
}
if err != nil {
return nil, err
}
switch ex.Operation {
case moss.OperationSet:
batch.Set(key, val)
case moss.OperationDel:
batch.Delete(key)
case moss.OperationMerge:
val, err = ssHigher.Get(key, readOptions)
if err != nil {
return nil, err
}
if val != nil {
batch.Set(key, val)
} else {
batch.Delete(key)
}
default:
return nil, fmt.Errorf("moss store, update,"+
" unexpected operation, ex: %v", ex)
}
i++
err = iter.Next()
if err == moss.ErrIteratorDone {
break
}
if err != nil {
return nil, err
}
if maxBatchSize > 0 && i%maxBatchSize == 0 {
err = kvWriter.ExecuteBatch(batch)
if err != nil {
return nil, err
}
err = batch.Close()
if err != nil {
return nil, err
}
batch = kvWriter.NewBatch()
}
}
if i > 0 {
s.logf("llStore.update, ExecuteBatch,"+
" path: %s, total: %d, start", s.llConfig["path"], i)
err = kvWriter.ExecuteBatch(batch)
if err != nil {
return nil, err
}
s.logf("llStore.update, ExecuteBatch,"+
" path: %s: total: %d, done", s.llConfig["path"], i)
}
}
kvReader, err := s.kvStore.Reader()
if err != nil {
return nil, err
}
s.logf("llStore.update, new reader")
return &llSnapshot{
llStore: s.addRef(),
kvReader: kvReader,
refs: 1,
}, nil
}
// 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
}