feat(network): add state diff part struct identical to protobuf

crates/papyrus_protobuf/src/sync.rs

@@ -1,4 +1,8 @@
+use indexmap::IndexMap;
 use starknet_api::block::{BlockHash, BlockHeader, BlockNumber, BlockSignature};
+use starknet_api::core::{ClassHash, CompiledClassHash, ContractAddress, Nonce};
+use starknet_api::hash::StarkFelt;
+use starknet_api::state::StorageKey;
 
 #[derive(Debug, PartialEq, Eq, Clone, Copy, Default, Hash)]
 pub enum Direction {
@@ -33,3 +37,27 @@ pub struct SignedBlockHeader {
     pub block_header: BlockHeader,
     pub signatures: Vec<BlockSignature>,
 }
+
+// TODO(shahak): Implement conversion to/from Vec<u8>.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct StateDiffsResponse(pub Option<StateDiffChunk>);
+
+// TODO(shahak): Implement conversion to/from protobuf.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum StateDiffChunk {
+    ContractDiff {
+        contract_address: ContractAddress,
+        // Has value only if the contract was deployed or replaced in this block.
+        class_hash: Option<ClassHash>,
+        // Has value only if the nonce was updated in this block.
+        nonce: Option<Nonce>,
+        storage_diffs: IndexMap<StorageKey, StarkFelt>,
+    },
+    DeclaredClass {
+        class_hash: ClassHash,
+        compiled_class_hash: CompiledClassHash,
+    },
+    DeprecatedDeclaredClass {
+        class_hash: ClassHash,
+    },
+}