refactor(state): split the old state into state reader and state writer structs

blockchain/blockchain.go

@@ -128,7 +128,7 @@ func (b *Blockchain) Network() *utils.Network {
 func (b *Blockchain) StateCommitment() (felt.Felt, error) {
 	b.listener.OnRead("StateCommitment")
 	batch := b.database.NewIndexedBatch() // this is a hack because we don't need to write to the db
-	return core.NewState(batch).Commitment()
+	return core.NewStateSnapshotReader(batch).Commitment()
 }
 
 // Height returns the latest block height. If blockchain is empty nil is returned.

core/contract.go

@@ -164,8 +164,8 @@ func (c *ContractUpdater) UpdateStorage(diff map[felt.Felt]*felt.Felt, cb OnValu
 	return cStorage.Commit()
 }
 
-func ContractStorage(addr, key *felt.Felt, txn db.IndexedBatch) (felt.Felt, error) {
-	cStorage, err := storage(addr, txn)
+func ContractStorage(addr, key *felt.Felt, txn db.KeyValueReader) (felt.Felt, error) {
+	cStorage, err := storageReader(addr, txn)
 	if err != nil {
 		return felt.Felt{}, err
 	}
@@ -193,3 +193,12 @@ func storage(addr *felt.Felt, txn db.IndexedBatch) (*trie.Trie, error) {
 	addrBytes := addr.Marshal()
 	return trie.NewTriePedersen(txn, db.ContractStorage.Key(addrBytes), ContractStorageTrieHeight)
 }
+
+func storageReader(addr *felt.Felt, txn db.KeyValueReader) (*trie.TrieReader, error) {
+	addrBytes := addr.Marshal()
+	return trie.NewTrieReaderPedersen(
+		txn,
+		db.ContractStorage.Key(addrBytes),
+		ContractStorageTrieHeight,
+	)
+}

core/pending_state.go

@@ -9,8 +9,6 @@ import (
 	"github.com/NethermindEth/juno/db"
 )
 
-var feltOne = new(felt.Felt).SetUint64(1)
-
 type PendingState struct {
 	stateDiff  *StateDiff
 	newClasses map[felt.Felt]ClassDefinition
@@ -136,7 +134,8 @@ func (p *PendingStateWriter) IncrementNonce(contractAddress *felt.Felt) error {
 	if err != nil {
 		return fmt.Errorf("get contract nonce: %v", err)
 	}
-	p.stateDiff.Nonces[*contractAddress] = currentNonce.Add(&currentNonce, feltOne)
+	nextNonce := new(felt.Felt).Add(&currentNonce, &felt.One)
+	p.stateDiff.Nonces[*contractAddress] = nextNonce
 	return nil
 }