minor changes

fixed_merkle_tree.go

@@ -124,12 +124,16 @@ func DeserializeMerkleTree(data SerializedTreeState, hashFn HashFunction) (*Merk
 
 	out := &MerkleTree{
 		BaseTree: &BaseTree{
-			levels: data.Levels,
+			levels: data.GetLevels(),
 			layers: layers,
 			zeros:  zeros,
 			hashFn: hashFn,
 		},
 	}
+	// check against root
+	if !out.Root().Cmp(data.GetRoot()) {
+		return nil, fmt.Errorf("root mismatch")
+	}
 	out.zeroElement = out.zeros[0]
 	return out, nil
 }

types.go

@@ -1,37 +1,64 @@
 package fMerkleTree
 
-import "encoding/hex"
+import (
+	"bytes"
+	"encoding/hex"
+	"math/big"
+)
 
 type Element []byte
 
 func (e Element) Hex() string {
 	return hex.EncodeToString(e)
 }
 
+func (e Element) BigInt() *big.Int {
+	return big.NewInt(0).SetBytes(e)
+}
+
+func (e Element) Cmp(x Element) bool {
+	return bytes.Compare(e, x) == 0
+}
+
 type HashFunction func(left Element, right Element) []byte
 
 type ComparatorFunction func(left Element, right Element) bool
 
-type SerializedTreeState struct {
-	Levels int    `db:"levels"`
-	Layers []byte `db:"layers"`
-	Zeros  []byte `db:"zeros"`
-	ID     int    `db:"id"`
+type SerializedTreeState interface {
+	GetLevels() int
+	GetRoot() Element
+	GetLayers() ([][]Element, error)
+	GetZeros() ([]Element, error)
+}
+
+type serializedTreeState struct {
+	Root   Element `db:"root"`
+	Levels int     `db:"levels"`
+	Layers []byte  `db:"layers"`
+	Zeros  []byte  `db:"zeros"`
+	ID     int     `db:"id"`
+}
+
+func (st *serializedTreeState) GetRoot() Element {
+	return st.Root
+}
+
+func (st *serializedTreeState) GetLevels() int {
+	return st.Levels
 }
 
-func (st SerializedTreeState) GetLayers() ([][]Element, error) {
+func (st *serializedTreeState) GetLayers() ([][]Element, error) {
 	var out [][]Element
 	return out, GobDecode(st.Layers, &out)
 }
 
-func (st SerializedTreeState) GetZeros() ([]Element, error) {
+func (st *serializedTreeState) GetZeros() ([]Element, error) {
 	var out []Element
 	return out, GobDecode(st.Zeros, &out)
 }
 
 func NewSerializedTreeState(tree *MerkleTree) (SerializedTreeState, error) {
-	var out SerializedTreeState
-	out.Levels = tree.levels
+	out := &serializedTreeState{Levels: tree.levels, Root: tree.Root()}
 	var err error
 	out.Layers, err = GobEncode(tree.layers)
 	if err != nil {