Update Poseidon version, add mt.Snapshot

go.mod

@@ -4,7 +4,7 @@ go 1.14
 
 require (
 	github.com/iden3/go-iden3-core v0.0.8
-	github.com/iden3/go-iden3-crypto v0.0.5
+	github.com/iden3/go-iden3-crypto v0.0.6-0.20200723082457-29a66457f0bf
 	github.com/sirupsen/logrus v1.5.0
 	github.com/stretchr/testify v1.5.1
 	github.com/syndtr/goleveldb v1.0.1-0.20190923125748-758128399b1d

go.sum

@@ -114,6 +114,8 @@ github.com/iden3/go-iden3-core v0.0.8 h1:PLw7iCiX7Pw1dqBkR+JaLQWqB5RKd+vgu25UBdv
 github.com/iden3/go-iden3-core v0.0.8/go.mod h1:URNjIhMql6sEbWubIGrjJdw5wHCE1Pk1XghxjBOtA3s=
 github.com/iden3/go-iden3-crypto v0.0.5 h1:inCSm5a+ry+nbpVTL/9+m6UcIwSv6nhUm0tnIxEbcps=
 github.com/iden3/go-iden3-crypto v0.0.5/go.mod h1:XKw1oDwYn2CIxKOtr7m/mL5jMn4mLOxAxtZBRxQBev8=
+github.com/iden3/go-iden3-crypto v0.0.6-0.20200723082457-29a66457f0bf h1:/7L5dEqctuzJY2g8OEQct+1Y+n2sMKyd4JoYhw2jy1s=
+github.com/iden3/go-iden3-crypto v0.0.6-0.20200723082457-29a66457f0bf/go.mod h1:XKw1oDwYn2CIxKOtr7m/mL5jMn4mLOxAxtZBRxQBev8=
 github.com/iden3/go-wasm3 v0.0.1/go.mod h1:j+TcAB94Dfrjlu5kJt83h2OqAU+oyNUTwNZnQyII1sI=
 github.com/influxdata/influxdb v1.2.3-0.20180221223340-01288bdb0883/go.mod h1:qZna6X/4elxqT3yI9iZYdZrWWdeFOOprn86kgg4+IzY=
 github.com/influxdata/influxdb v1.7.8/go.mod h1:qZna6X/4elxqT3yI9iZYdZrWWdeFOOprn86kgg4+IzY=

merkletree.go

@@ -10,8 +10,8 @@ import (
 	"sync"
 
 	"github.com/iden3/go-iden3-core/common"
-	"github.com/iden3/go-merkletree/db"
 	cryptoUtils "github.com/iden3/go-iden3-crypto/utils"
+	"github.com/iden3/go-merkletree/db"
 )
 
 const (
@@ -141,6 +141,16 @@ func (mt *MerkleTree) Root() *Hash {
 	return mt.rootKey
 }
 
+func (mt *MerkleTree) Snapshot(rootKey *Hash) (*MerkleTree, error) {
+	mt.RLock()
+	defer mt.RUnlock()
+	_, err := mt.GetNode(rootKey)
+	if err != nil {
+		return nil, err
+	}
+	return &MerkleTree{db: mt.db, maxLevels: mt.maxLevels, rootKey: rootKey, writable: false}, nil
+}
+
 // Add adds a Key & Value into the MerkleTree. Where the `k` determines the path from the Root to the Leaf.
 func (mt *MerkleTree) Add(k, v *big.Int) error {
 	// verify that the MerkleTree is writable

utils.go

@@ -8,7 +8,7 @@ import (
 )
 
 // HashElems performs a poseidon hash over the array of ElemBytes.
-// Uses poseidon.PoseidonHash to be compatible with the circom circuits
+// Uses poseidon.Hash to be compatible with the circom circuits
 // implementations.
 // The maxim slice input size is poseidon.T
 func HashElems(elems ...*big.Int) (*Hash, error) {
@@ -21,7 +21,7 @@ func HashElems(elems ...*big.Int) (*Hash, error) {
 		return nil, err
 	}
 
-	poseidonHash, err := poseidon.PoseidonHash(bi)
+	poseidonHash, err := poseidon.Hash(bi)
 	if err != nil {
 		return nil, err
 	}
@@ -41,7 +41,7 @@ func HashElemsKey(key *big.Int, elems ...*big.Int) (*Hash, error) {
 		return nil, err
 	}
 	copy(bi[len(elems):], []*big.Int{key})
-	poseidonHash, err := poseidon.PoseidonHash(bi)
+	poseidonHash, err := poseidon.Hash(bi)
 	if err != nil {
 		return nil, err
 	}