1 files changed, 40 insertions, 0 deletions
diff --git a/swarm/storage/swarmhasher.go b/swarm/storage/swarmhasher.go
new file mode 100644
index 000000000..38b86373c
--- /dev/null
+++ b/swarm/storage/swarmhasher.go
@@ -0,0 +1,40 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package storage
+
+import (
+	"hash"
+)
+
+const (
+	BMTHash  = "BMT"
+	SHA3Hash = "SHA3" // http://golang.org/pkg/hash/#Hash
+)
+
+type SwarmHash interface {
+	hash.Hash
+	ResetWithLength([]byte)
+}
+
+type HashWithLength struct {
+	hash.Hash
+}
+
+func (self *HashWithLength) ResetWithLength(length []byte) {
+	self.Reset()
+	self.Write(length)
+}