1 files changed, 88 insertions, 0 deletions
diff --git a/swarm/storage/mru/updateheader.go b/swarm/storage/mru/updateheader.go
new file mode 100644
index 000000000..3ac20c189
--- /dev/null
+++ b/swarm/storage/mru/updateheader.go
@@ -0,0 +1,88 @@
+// Copyright 2018 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 mru
+
+import (
+	"github.com/ethereum/go-ethereum/swarm/storage"
+)
+
+// updateHeader models the non-payload components of a Resource Update
+type updateHeader struct {
+	UpdateLookup        // UpdateLookup contains the information required to locate this resource (components of the search key used to find it)
+	multihash    bool   // Whether the data in this Resource Update should be interpreted as multihash
+	metaHash     []byte // SHA3 hash of the metadata chunk (less ownerAddr). Used to prove ownerhsip of the resource.
+}
+
+const metaHashLength = storage.KeyLength
+
+// updateLookupLength bytes
+// 1 byte flags (multihash bool for now)
+// 32 bytes metaHash
+const updateHeaderLength = updateLookupLength + 1 + metaHashLength
+
+// binaryPut serializes the resource header information into the given slice
+func (h *updateHeader) binaryPut(serializedData []byte) error {
+	if len(serializedData) != updateHeaderLength {
+		return NewErrorf(ErrInvalidValue, "Incorrect slice size to serialize updateHeaderLength. Expected %d, got %d", updateHeaderLength, len(serializedData))
+	}
+	if len(h.metaHash) != metaHashLength {
+		return NewError(ErrInvalidValue, "updateHeader.binaryPut called without metaHash set")
+	}
+	if err := h.UpdateLookup.binaryPut(serializedData[:updateLookupLength]); err != nil {
+		return err
+	}
+	cursor := updateLookupLength
+	copy(serializedData[cursor:], h.metaHash[:metaHashLength])
+	cursor += metaHashLength
+
+	var flags byte
+	if h.multihash {
+		flags |= 0x01
+	}
+
+	serializedData[cursor] = flags
+	cursor++
+
+	return nil
+}
+
+// binaryLength returns the expected size of this structure when serialized
+func (h *updateHeader) binaryLength() int {
+	return updateHeaderLength
+}
+
+// binaryGet restores the current updateHeader instance from the information contained in the passed slice
+func (h *updateHeader) binaryGet(serializedData []byte) error {
+	if len(serializedData) != updateHeaderLength {
+		return NewErrorf(ErrInvalidValue, "Incorrect slice size to read updateHeaderLength. Expected %d, got %d", updateHeaderLength, len(serializedData))
+	}
+
+	if err := h.UpdateLookup.binaryGet(serializedData[:updateLookupLength]); err != nil {
+		return err
+	}
+	cursor := updateLookupLength
+	h.metaHash = make([]byte, metaHashLength)
+	copy(h.metaHash[:storage.KeyLength], serializedData[cursor:cursor+storage.KeyLength])
+	cursor += metaHashLength
+
+	flags := serializedData[cursor]
+	cursor++
+
+	h.multihash = flags&0x01 != 0
+
+	return nil
+}