Partial MPT: account trie (#260)

cairo/ethereum/cancun/fork_types.cairo

@@ -1,11 +1,9 @@
 from starkware.cairo.common.alloc import alloc
-from starkware.cairo.common.math_cmp import is_le
-from starkware.cairo.common.cairo_builtins import BitwiseBuiltin, KeccakBuiltin
-from starkware.cairo.common.memcpy import memcpy
-from src.utils.bytes import felt_to_bytes_little, uint256_to_bytes32_little, felt_to_bytes20_little
-from ethereum.crypto.hash import Hash32, keccak256
+
 from ethereum_types.bytes import Bytes20, Bytes256, Bytes, BytesStruct
-from ethereum_types.numeric import Uint, U256
+from ethereum_types.numeric import Uint, U256, U256Struct
+from ethereum.crypto.hash import Hash32
+
 using Address = Bytes20;
 using Root = Hash32;
 
@@ -30,3 +28,26 @@ struct AccountStruct {
 struct Account {
     value: AccountStruct*,
 }
+
+struct AddressAccountDictAccess {
+    key: Address,
+    prev_value: Account,
+    new_value: Account,
+}
+
+struct MappingAddressAccountStruct {
+    dict_ptr_start: AddressAccountDictAccess*,
+    dict_ptr: AddressAccountDictAccess*,
+}
+
+struct MappingAddressAccount {
+    value: MappingAddressAccountStruct*,
+}
+
+func EMPTY_ACCOUNT() -> Account {
+    tempvar balance = U256(new U256Struct(0, 0));
+    let (data) = alloc();
+    tempvar code = Bytes(new BytesStruct(data=data, len=0));
+    tempvar account = Account(value=new AccountStruct(nonce=Uint(0), balance=balance, code=code));
+    return account;
+}

cairo/ethereum/cancun/trie.cairo

@@ -22,7 +22,7 @@ from ethereum_types.bytes import (
     TupleMappingBytesBytesStruct,
 )
 from ethereum.cancun.blocks import Receipt, Withdrawal
-from ethereum.cancun.fork_types import Account, Address, Root
+from ethereum.cancun.fork_types import Account, MappingAddressAccount
 from ethereum.cancun.transactions import LegacyTransaction
 from ethereum.rlp import (
     Extended,
@@ -126,11 +126,15 @@ struct Node {
     value: NodeEnum*,
 }
 
-// struct TrieStruct {
-//     secured: bool,
-//     default: V,
-//     _data: Dict[K, V],
-// }
+struct TrieAddressAccountStruct {
+    secured: bool,
+    default: Account,
+    _data: MappingAddressAccount,
+}
+
+struct TrieAddressAccount {
+    value: TrieAddressAccountStruct*,
+}
 
 func encode_internal_node{
     range_check_ptr, bitwise_ptr: BitwiseBuiltin*, keccak_ptr: KeccakBuiltin*

cairo/ethereum_types/bytes.cairo

@@ -12,8 +12,9 @@ struct Bytes8 {
 struct Bytes20 {
     value: felt,
 }
+using Bytes32Struct = Uint256;
 struct Bytes32 {
-    value: Uint256*,
+    value: Bytes32Struct*,
 }
 struct Bytes256 {
     value: U128*,

cairo/ethereum_types/numeric.cairo

@@ -14,8 +14,10 @@ struct U128 {
 struct Uint {
     value: felt,
 }
+
+using U256Struct = Uint256;
 struct U256 {
-    value: Uint256*,
+    value: U256Struct*,
 }
 
 struct SetUintDictAccess {

cairo/tests/ethereum/cancun/test_fork_types.py

@@ -0,0 +1,6 @@
+from ethereum.cancun.fork_types import EMPTY_ACCOUNT
+
+
+class TestForkTypes:
+    def test_account_default(self, cairo_run):
+        assert EMPTY_ACCOUNT == cairo_run("EMPTY_ACCOUNT")

cairo/tests/test_serde.py

@@ -166,6 +166,7 @@ def test_type(
             Mapping[Bytes, Bytes],
             Tuple[Mapping[Bytes, Bytes], ...],
             Set[Uint],
+            Mapping[Address, Account],
         ],
     ):
         assume(no_empty_sequence(b))

cairo/tests/utils/args_gen.py

@@ -116,6 +116,9 @@
     ("ethereum", "cancun", "trie", "BranchNode"): BranchNode,
     ("ethereum", "cancun", "trie", "InternalNode"): InternalNode,
     ("ethereum", "cancun", "trie", "Node"): Node,
+    ("ethereum", "cancun", "fork_types", "MappingAddressAccount"): Mapping[
+        Address, Account
+    ],
 }
 
 # In the EELS, some functions are annotated with Sequence while it's actually just Bytes.