// newKeyValueFromJSONConfig returns a KeyValue implementation on top of a
// github.com/syndtr/goleveldb/leveldb file.
func newKeyValueFromJSONConfig(cfg jsonconfig.Obj) (sorted.KeyValue, error) {
file := cfg.RequiredString("file")
if err := cfg.Validate(); err != nil {
return nil, err
}
strictness := opt.DefaultStrict
if env.IsDev() {
// Be more strict in dev mode.
strictness = opt.StrictAll
}
opts := &opt.Options{
// The default is 10,
// 8 means 2.126% or 1/47th disk check rate,
// 10 means 0.812% error rate (1/2^(bits/1.44)) or 1/123th disk check rate,
// 12 means 0.31% or 1/322th disk check rate.
// TODO(tgulacsi): decide which number is the best here. Till that go with the default.
Filter: filter.NewBloomFilter(10),
Strict: strictness,
}
db, err := leveldb.OpenFile(file, opts)
if err != nil {
return nil, err
}
is := &kvis{
db: db,
path: file,
opts: opts,
readOpts: &opt.ReadOptions{Strict: strictness},
// On machine crash we want to reindex anyway, and
// fsyncs may impose great performance penalty.
writeOpts: &opt.WriteOptions{Sync: false},
}
return is, nil
}
func (is *kvis) Wipe() error {
// Close the already open DB.
if err := is.db.Close(); err != nil {
return err
}
if err := os.RemoveAll(is.path); err != nil {
return err
}
db, err := leveldb.OpenFile(is.path, is.opts)
if err != nil {
return fmt.Errorf("error creating %s: %v", is.path, err)
}
is.db = db
return nil
}