// DeleteAll deletes all key-value associated with a context (data instance and version).
func (db *LevelDB) DeleteAll(ctx storage.Context, allVersions bool) error {
if ctx == nil {
return fmt.Errorf("Received nil context in Delete()")
}
dvid.StartCgo()
// Don't have to worry about tombstones. Delete all keys from all versions for this instance id.
minTKey := storage.MinTKey(storage.TKeyMinClass)
maxTKey := storage.MaxTKey(storage.TKeyMaxClass)
vctx, ok := ctx.(storage.VersionedCtx)
if !ok {
return fmt.Errorf("Non-versioned context passed to DELETE ALL VERSIONS in basholeveldb driver: %v", ctx)
}
minKey, err := vctx.MinVersionKey(minTKey)
if err != nil {
return err
}
maxKey, err := vctx.MaxVersionKey(maxTKey)
if err != nil {
return err
}
const BATCH_SIZE = 10000
batch := db.NewBatch(ctx).(*goBatch)
ro := levigo.NewReadOptions()
it := db.ldb.NewIterator(ro)
defer func() {
it.Close()
dvid.StopCgo()
}()
numKV := 0
it.Seek(minKey)
deleteVersion := ctx.VersionID()
for {
if it.Valid() {
itKey := it.Key()
storage.StoreKeyBytesRead <- len(itKey)
// Did we pass the final key?
if bytes.Compare(itKey, maxKey) > 0 {
break
}
if !allVersions {
_, v, _, err := storage.DataKeyToLocalIDs(itKey)
if err != nil {
return fmt.Errorf("Error on DELETE ALL for version %d: %v", ctx.VersionID(), err)
}
if v != deleteVersion {
it.Next()
continue
}
}
batch.WriteBatch.Delete(itKey)
if (numKV+1)%BATCH_SIZE == 0 {
if err := batch.Commit(); err != nil {
batch.Close()
return fmt.Errorf("Error on DELETE ALL at key-value pair %d: %v", numKV, err)
}
batch = db.NewBatch(ctx).(*goBatch)
}
numKV++
it.Next()
} else {
break
}
}
if numKV%BATCH_SIZE != 0 {
if err := batch.Commit(); err != nil {
batch.Close()
return fmt.Errorf("Error on last batch DELETE: %v\n", err)
}
}
dvid.Debugf("Deleted %d key-value pairs via DELETE ALL for %s.\n", numKV, ctx)
return nil
}