func (d *datastore) Delete(key ds.Key) (err error) {
err = d.DB.Delete(key.Bytes(), nil)
if err == leveldb.ErrNotFound {
return ds.ErrNotFound
}
return err
}
// Returns ErrInvalidType if value is not of type []byte.
//
// Note: using sync = false.
// see http://godoc.org/github.com/syndtr/goleveldb/leveldb/opt#WriteOptions
func (d *datastore) Put(key ds.Key, value interface{}) (err error) {
val, ok := value.([]byte)
if !ok {
return ds.ErrInvalidType
}
return d.DB.Put(key.Bytes(), val, nil)
}
func (d *datastore) Get(key ds.Key) (value interface{}, err error) {
val, err := d.DB.Get(key.Bytes(), nil)
if err != nil {
if err == leveldb.ErrNotFound {
return nil, ds.ErrNotFound
}
return nil, err
}
return val, nil
}
// PrefixTransform constructs a KeyTransform with a pair of functions that
// add or remove the given prefix key.
//
// Warning: will panic if prefix not found when it should be there. This is
// to avoid insidious data inconsistency errors.
func PrefixTransform(prefix ds.Key) ktds.KeyTransform {
return &ktds.Pair{
// Convert adds the prefix
Convert: func(k ds.Key) ds.Key {
return prefix.Child(k)
},
// Invert removes the prefix. panics if prefix not found.
Invert: func(k ds.Key) ds.Key {
if !prefix.IsAncestorOf(k) {
fmt.Errorf("Expected prefix (%s) in key (%s)", prefix, k)
panic("expected prefix not found")
}
s := strings.TrimPrefix(k.String(), prefix.String())
return ds.NewKey(s)
},
}
}
// KeyFilename returns the filename associated with `key`
func (d *Datastore) KeyFilename(key ds.Key) string {
return filepath.Join(d.path, key.String(), ObjectKeySuffix)
}
func (d *datastore) Has(key ds.Key) (exists bool, err error) {
return d.DB.Has(key.Bytes(), nil)
}