feat: destroy_storage, destroy_account (#439)

destroy storage destroy account closes #406 --------- Co-authored-by: Mathieu <60658558+enitrat@users.noreply.github.com>
kkrt-labs · Jan 16, 2025 · bbc2428 · bbc2428
1 parent e023608
commit bbc2428
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diff --git a/cairo/ethereum/cancun/state.cairo b/cairo/ethereum/cancun/state.cairo
@@ -213,6 +213,13 @@ func get_storage{poseidon_ptr: PoseidonBuiltin*, state: State}(
     return value;
 }
 
+func destroy_account{poseidon_ptr: PoseidonBuiltin*, state: State}(address: Address) {
+    destroy_storage(address);
+    let none_account = OptionalAccount(cast(0, AccountStruct*));
+    set_account(address, none_account);
+    return ();
+}
+
 func set_storage{poseidon_ptr: PoseidonBuiltin*, state: State}(
     address: Address, key: Bytes32, value: U256
 ) {
@@ -305,6 +312,67 @@ func set_storage{poseidon_ptr: PoseidonBuiltin*, state: State}(
     return ();
 }
 
+func destroy_storage{poseidon_ptr: PoseidonBuiltin*, state: State}(address: Address) {
+    alloc_locals;
+
+    let storage_tries = state.value._storage_tries;
+    let fp_and_pc = get_fp_and_pc();
+    local __fp__: felt* = fp_and_pc.fp_val;
+
+    let storage_tries_dict_ptr = cast(storage_tries.value.dict_ptr, DictAccess*);
+
+    // Use `hashdict_get` instead of `hashdict_read` because `MappingAddressTrieBytes32U256` is not a
+    // `default_dict`. Accessing a key that does not exist in the dict would have panicked for `hashdict_read`.
+    let (pointer) = hashdict_get{dict_ptr=storage_tries_dict_ptr}(1, &address.value);
+
+    if (pointer == 0) {
+        // rebind storage_tries
+        let new_storage_tries_dict_ptr = cast(
+            storage_tries_dict_ptr, AddressTrieBytes32U256DictAccess*
+        );
+        tempvar storage_tries = MappingAddressTrieBytes32U256(
+            new MappingAddressTrieBytes32U256Struct(
+                dict_ptr_start=storage_tries.value.dict_ptr_start,
+                dict_ptr=new_storage_tries_dict_ptr,
+                original_mapping=storage_tries.value.original_mapping,
+            ),
+        );
+        tempvar state = State(
+            new StateStruct(
+                _main_trie=state.value._main_trie,
+                _storage_tries=storage_tries,
+                _snapshots=state.value._snapshots,
+                created_accounts=state.value.created_accounts,
+            ),
+        );
+        return ();
+    }
+
+    // del state._storage_tries[address] is equivalent to setting the value to 0
+    hashdict_write{dict_ptr=storage_tries_dict_ptr}(1, &address.value, 0);
+
+    let new_storage_tries_dict_ptr = cast(
+        storage_tries_dict_ptr, AddressTrieBytes32U256DictAccess*
+    );
+    tempvar new_storage_tries = MappingAddressTrieBytes32U256(
+        new MappingAddressTrieBytes32U256Struct(
+            dict_ptr_start=storage_tries.value.dict_ptr_start,
+            dict_ptr=new_storage_tries_dict_ptr,
+            original_mapping=storage_tries.value.original_mapping,
+        ),
+    );
+    tempvar state = State(
+        new StateStruct(
+            _main_trie=state.value._main_trie,
+            _storage_tries=new_storage_tries,
+            _snapshots=state.value._snapshots,
+            created_accounts=state.value.created_accounts,
+        ),
+    );
+
+    return ();
+}
+
 func get_transient_storage{poseidon_ptr: PoseidonBuiltin*, transient_storage: TransientStorage}(
     address: Address, key: Bytes32
 ) -> U256 {

diff --git a/cairo/tests/ethereum/cancun/test_state.py b/cairo/tests/ethereum/cancun/test_state.py
@@ -11,6 +11,8 @@
 from ethereum.cancun.state import (
     account_exists,
     account_has_code_or_nonce,
+    destroy_account,
+    destroy_storage,
     get_account,
     get_account_optional,
     get_storage,
@@ -78,6 +80,13 @@ def test_set_account(self, cairo_run, data, account: Optional[Account]):
         set_account(state, address, account)
         assert state_cairo == state
 
+    @given(data=state_and_address_and_optional_key())
+    def test_destroy_account(self, cairo_run, data):
+        state, address = data
+        state_cairo = cairo_run("destroy_account", state, address)
+        destroy_account(state, address)
+        assert state_cairo == state
+
     @given(data=state_and_address_and_optional_key())
     def test_account_has_code_or_nonce(self, cairo_run, data):
         state, address = data
@@ -134,6 +143,13 @@ def test_set_storage(self, cairo_run, data, value: U256):
         set_storage(state, address, key, value)
         assert state_cairo == state
 
+    @given(data=state_and_address_and_optional_key())
+    def test_destroy_storage(self, cairo_run, data):
+        state, address = data
+        state_cairo = cairo_run("destroy_storage", state, address)
+        destroy_storage(state, address)
+        assert state_cairo == state
+
 
 class TestTransientStorage:
     @given(