chore!: Serialize, Deserialize and NoteInterface as Traits (#4135)

Closes: AztecProtocol/aztec-packages#3756,
AztecProtocol/aztec-packages#2838


Taking advantage of @jfecher's fantastic work in
noir-lang/noir#4000, implemented `Serialize<N>`
and `Deserialize<N>`. Together with `NoteInterface`, they make possible
getting rid of all the serialization interfaces, which greatly simplify
how the storage is handled and opens the door to further improvements.
~~Still some clutter to go, the lengths are still needed in some
places.~~


![Brace yourself](https://i.imgflip.com/8crkve.jpg)

I'm so sorry.

---------

Co-authored-by: sirasistant <[email protected]>

address-note/src/address_note.nr

@@ -2,7 +2,10 @@
 use dep::aztec::log::emit_encrypted_log;
 // docs:end:encrypted_import
 use dep::aztec::{
-    protocol_types::address::AztecAddress,
+    protocol_types::{
+        address::AztecAddress,
+        traits::{Serialize, Deserialize, Empty}
+    },
     note::{
         note_header::NoteHeader,
         note_interface::NoteInterface,
@@ -14,7 +17,7 @@ use dep::aztec::{
         get_public_key::get_public_key,
     },
     hash::pedersen_hash,
-    context::PrivateContext,
+    context::PrivateContext
 };
 
 global ADDRESS_NOTE_LEN: Field = 3;
@@ -28,39 +31,31 @@ struct AddressNote {
     header: NoteHeader,
 }
 
-impl AddressNote {
-    pub fn new(address: AztecAddress, owner: AztecAddress) -> Self {
-        let randomness = rand();
-        AddressNote {
-            address,
-            owner,
-            randomness,
-            header: NoteHeader::empty(),
-        }
-    }
-// docs:end:address_note_def
-
-
-    pub fn serialize(self) -> [Field; ADDRESS_NOTE_LEN]{
+impl Serialize<ADDRESS_NOTE_LEN> for AddressNote {
+    fn serialize(self) -> [Field; ADDRESS_NOTE_LEN]{
         [self.address.to_field(), self.owner.to_field(), self.randomness]
     }
+}
 
-    pub fn deserialize(serialized_note: [Field; ADDRESS_NOTE_LEN]) -> Self {
+impl Deserialize<ADDRESS_NOTE_LEN> for AddressNote {
+    fn deserialize(serialized_note: [Field; ADDRESS_NOTE_LEN]) -> Self {
         AddressNote {
             address: AztecAddress::from_field(serialized_note[0]),
             owner: AztecAddress::from_field(serialized_note[1]),
             randomness: serialized_note[2],
             header: NoteHeader::empty(),
         }
     }
+}
 
-    pub fn compute_note_hash(self) -> Field {
+impl NoteInterface for AddressNote {
+    fn compute_note_hash(self) -> Field {
         // TODO(#1205) Should use a non-zero generator index.
         pedersen_hash(self.serialize(), 0)
     }
 
-    pub fn compute_nullifier(self, context: &mut PrivateContext) -> Field {
-        let note_hash_for_nullify = compute_note_hash_for_read_or_nullify(AddressNoteMethods, self);
+    fn compute_nullifier(self, context: &mut PrivateContext) -> Field {
+        let note_hash_for_nullify = compute_note_hash_for_read_or_nullify(self);
         let secret = context.request_nullifier_secret_key(self.owner);
         // TODO(#1205) Should use a non-zero generator index.
         pedersen_hash([
@@ -70,8 +65,8 @@ impl AddressNote {
         ],0)
     }
 
-    pub fn compute_nullifier_without_context(self) -> Field {
-        let note_hash_for_nullify = compute_note_hash_for_read_or_nullify(AddressNoteMethods, self);
+    fn compute_nullifier_without_context(self) -> Field {
+        let note_hash_for_nullify = compute_note_hash_for_read_or_nullify(self);
         let secret = get_nullifier_secret_key(self.owner);
         // TODO(#1205) Should use a non-zero generator index.
         pedersen_hash([
@@ -81,12 +76,16 @@ impl AddressNote {
         ],0)
     }
 
-    pub fn set_header(&mut self, header: NoteHeader) {
+    fn set_header(&mut self, header: NoteHeader) {
         self.header = header;
     }
 
+    fn get_header(note: Self) -> NoteHeader {
+        note.header
+    }
+
     // Broadcasts the note as an encrypted log on L1.
-    pub fn broadcast(self, context: &mut PrivateContext, slot: Field) {
+    fn broadcast(self, context: &mut PrivateContext, slot: Field) {
         let encryption_pub_key = get_public_key(self.owner);
         // docs:start:encrypted
         emit_encrypted_log(
@@ -100,46 +99,15 @@ impl AddressNote {
     }
 }
 
-fn deserialize(serialized_note: [Field; ADDRESS_NOTE_LEN]) -> AddressNote {
-    AddressNote::deserialize(serialized_note)
-}
-
-fn serialize(note: AddressNote) -> [Field; ADDRESS_NOTE_LEN] {
-    note.serialize()
-}
-
-fn compute_note_hash(note: AddressNote) -> Field {
-    note.compute_note_hash()
-}
-
-fn compute_nullifier(note: AddressNote, context: &mut PrivateContext) -> Field {
-    note.compute_nullifier(context)
-}
-
-fn compute_nullifier_without_context(note: AddressNote) -> Field {
-    note.compute_nullifier_without_context()
-}
-
-fn get_header(note: AddressNote) -> NoteHeader {
-    note.header
-}
-
-fn set_header(note: &mut AddressNote, header: NoteHeader) {
-    note.set_header(header);
-}
-
-// Broadcasts the note as an encrypted log on L1.
-fn broadcast(context: &mut PrivateContext, slot: Field, note: AddressNote) {
-    note.broadcast(context, slot);
+impl AddressNote {
+    pub fn new(address: AztecAddress, owner: AztecAddress) -> Self {
+        let randomness = rand();
+        AddressNote {
+            address,
+            owner,
+            randomness,
+            header: NoteHeader::empty(),
+        }
+    }
+// docs:end:address_note_def
 }
-
-global AddressNoteMethods = NoteInterface {
-    deserialize,
-    serialize,
-    compute_note_hash,
-    compute_nullifier,
-    compute_nullifier_without_context,
-    get_header,
-    set_header,
-    broadcast,
-};

authwit/src/account.nr

@@ -1,14 +1,13 @@
 use dep::aztec::context::{PrivateContext, PublicContext, Context};
 use dep::aztec::state_vars::{map::Map, public_state::PublicState};
-use dep::aztec::types::type_serialization::bool_serialization::{BoolSerializationMethods,BOOL_SERIALIZED_LEN};
 
 use crate::entrypoint::EntrypointPayload;
 use crate::auth::IS_VALID_SELECTOR;
 
 struct AccountActions {
   context: Context,
   is_valid_impl: fn(&mut PrivateContext, Field) -> bool,
-  approved_action: Map<Field, PublicState<bool, BOOL_SERIALIZED_LEN>>,
+  approved_action: Map<Field, PublicState<bool>>,
 }
 
 impl AccountActions {
@@ -20,7 +19,7 @@ impl AccountActions {
         context,
         approved_action_storage_slot,
         |context, slot| {
-          PublicState::new(context, slot, BoolSerializationMethods)
+          PublicState::new(context, slot)
         },
       ),
     }

authwit/src/entrypoint.nr

@@ -12,6 +12,7 @@ use dep::aztec::protocol_types::{
   address::AztecAddress,
   constants::GENERATOR_INDEX__SIGNATURE_PAYLOAD,
   hash::pedersen_hash,
+  traits::{Hash, Serialize}
 };
 
 global ACCOUNT_MAX_CALLS: Field = 4;
@@ -27,11 +28,13 @@ struct FunctionCall {
   is_public: bool,
 }
 
-impl FunctionCall {
+impl Serialize<FUNCTION_CALL_SIZE> for FunctionCall {
   fn serialize(self) -> [Field; FUNCTION_CALL_SIZE] {
     [self.args_hash, self.function_selector.to_field(), self.target_address.to_field(), self.is_public as Field]
   }
+}
 
+impl FunctionCall {
   fn to_be_bytes(self) -> [u8; FUNCTION_CALL_SIZE_IN_BYTES] {
     let mut bytes: [u8; FUNCTION_CALL_SIZE_IN_BYTES] = [0; FUNCTION_CALL_SIZE_IN_BYTES];
     let args_hash_bytes = self.args_hash.to_be_bytes(32);
@@ -58,14 +61,7 @@ struct EntrypointPayload {
 }
 // docs:end:entrypoint-struct
 
-impl EntrypointPayload {
-  fn hash(self) -> Field {
-    pedersen_hash(
-      self.serialize(), 
-      GENERATOR_INDEX__SIGNATURE_PAYLOAD
-    )
-  }
-
+impl Serialize<ENTRYPOINT_PAYLOAD_SIZE> for EntrypointPayload {
   // Serializes the entrypoint struct
   fn serialize(self) -> [Field; ENTRYPOINT_PAYLOAD_SIZE] {
     let mut fields: BoundedVec<Field, ENTRYPOINT_PAYLOAD_SIZE> = BoundedVec::new(0); 
@@ -75,7 +71,18 @@ impl EntrypointPayload {
     fields.push(self.nonce);
     fields.storage
   }
+}
+
+impl Hash for EntrypointPayload {
+  fn hash(self) -> Field {
+    pedersen_hash(
+      self.serialize(), 
+      GENERATOR_INDEX__SIGNATURE_PAYLOAD
+    )
+  }
+}
 
+impl EntrypointPayload {
   // Serializes the payload as an array of bytes. Useful for hashing with sha256.
   fn to_be_bytes(self) -> [u8; ENTRYPOINT_PAYLOAD_SIZE_IN_BYTES] {
     let mut bytes: [u8; ENTRYPOINT_PAYLOAD_SIZE_IN_BYTES] = [0; ENTRYPOINT_PAYLOAD_SIZE_IN_BYTES];

aztec/src/abi.nr

@@ -6,6 +6,7 @@ use dep::protocol_types::{
     },
     contrakt::deployment_data::ContractDeploymentData,
     hash::hash_args,
+    traits::{Hash, Serialize},
     header::Header,
 };
 
@@ -16,7 +17,7 @@ struct PrivateGlobalVariables {
 }
 // docs:end:private-global-variables
 
-impl PrivateGlobalVariables {
+impl Serialize<2> for PrivateGlobalVariables {
     fn serialize(self) -> [Field; 2] {
         [self.chain_id, self.version]
     }
@@ -31,7 +32,7 @@ struct PublicGlobalVariables {
 }
 // docs:end:public-global-variables
 
-impl PublicGlobalVariables {
+impl Serialize<4> for PublicGlobalVariables {
     fn serialize(self) -> [Field; 4] {
         [self.chain_id, self.version, self.block_number, self.timestamp]
     }
@@ -61,6 +62,12 @@ struct Hasher {
     fields: [Field],
 }
 
+impl Hash for Hasher {
+    fn hash(self) -> Field {
+        hash_args(self.fields)
+    }
+}
+
 impl Hasher {
     pub fn new()-> Self {
         Self { fields: [] }
@@ -75,8 +82,4 @@ impl Hasher {
             self.fields = self.fields.push_back(fields[i]);
         }
     }
-
-    pub fn hash(self) -> Field {
-        hash_args(self.fields)
-    }
 }

aztec/src/context.nr

@@ -330,10 +330,10 @@ impl PrivateContext {
                 },
                 args_hash: reader.read(),
                 return_values: reader.read_array([0; RETURN_VALUES_LENGTH]), // +1
-                read_requests: reader.read_struct_array(SideEffect::deserialise, [SideEffect::empty(); MAX_READ_REQUESTS_PER_CALL]),
-                nullifier_key_validation_requests: reader.read_struct_array(NullifierKeyValidationRequest::deserialise, [NullifierKeyValidationRequest::empty(); MAX_NULLIFIER_KEY_VALIDATION_REQUESTS_PER_CALL]),
-                new_commitments: reader.read_struct_array(SideEffect::deserialise, [SideEffect::empty(); MAX_NEW_COMMITMENTS_PER_CALL]),
-                new_nullifiers: reader.read_struct_array(SideEffectLinkedToNoteHash::deserialise, [SideEffectLinkedToNoteHash::empty(); MAX_NEW_NULLIFIERS_PER_CALL]),
+                read_requests: reader.read_struct_array(SideEffect::deserialize, [SideEffect::empty(); MAX_READ_REQUESTS_PER_CALL]),
+                nullifier_key_validation_requests: reader.read_struct_array(NullifierKeyValidationRequest::deserialize, [NullifierKeyValidationRequest::empty(); MAX_NULLIFIER_KEY_VALIDATION_REQUESTS_PER_CALL]),
+                new_commitments: reader.read_struct_array(SideEffect::deserialize, [SideEffect::empty(); MAX_NEW_COMMITMENTS_PER_CALL]),
+                new_nullifiers: reader.read_struct_array(SideEffectLinkedToNoteHash::deserialize, [SideEffectLinkedToNoteHash::empty(); MAX_NEW_NULLIFIERS_PER_CALL]),
                 private_call_stack_hashes: reader.read_array([0; MAX_PRIVATE_CALL_STACK_LENGTH_PER_CALL]),
                 public_call_stack_hashes: reader.read_array([0; MAX_PUBLIC_CALL_STACK_LENGTH_PER_CALL]),
                 new_l2_to_l1_msgs: reader.read_array([0; MAX_NEW_L2_TO_L1_MSGS_PER_CALL]),

aztec/src/history/note_inclusion.nr

@@ -30,12 +30,11 @@ pub fn prove_note_commitment_inclusion(
 }
 
 pub fn prove_note_inclusion<Note, N>(
-    note_interface: NoteInterface<Note, N>,
     note_with_header: Note,
     block_number: u32, // The block at which we'll prove that the note exists
     context: PrivateContext
-) {
-    let note_commitment = compute_note_hash_for_read_or_nullify(note_interface, note_with_header);
+) where Note: NoteInterface {
+    let note_commitment = compute_note_hash_for_read_or_nullify(note_with_header);
 
     prove_note_commitment_inclusion(note_commitment, block_number, context);
 }

aztec/src/history/note_validity.nr

@@ -9,11 +9,10 @@ use crate::{
 
 // A helper function that proves that a note is valid at the given block number
 pub fn prove_note_validity<Note, N>(
-    note_interface: NoteInterface<Note, N>,
     note_with_header: Note,
     block_number: u32, // The block at which we'll prove that the note exists
     context: &mut PrivateContext
-) {
-    prove_note_inclusion(note_interface, note_with_header, block_number, *context);
-    prove_note_not_nullified(note_interface, note_with_header, block_number, context);
+) where Note: NoteInterface {
+    prove_note_inclusion(note_with_header, block_number, *context);
+    prove_note_not_nullified(note_with_header, block_number, context);
 }

aztec/src/history/nullifier_non_inclusion.nr

@@ -50,12 +50,11 @@ pub fn prove_nullifier_non_inclusion(
 }
 
 pub fn prove_note_not_nullified<Note, N>(
-    note_interface: NoteInterface<Note, N>,
     note_with_header: Note,
     block_number: u32, // The block at which we'll prove that the note was not nullified
     context: &mut PrivateContext
-) {
-    let nullifier = compute_siloed_nullifier(note_interface, note_with_header, context);
+) where Note: NoteInterface {
+    let nullifier = compute_siloed_nullifier(note_with_header, context);
 
     prove_nullifier_non_inclusion(nullifier, block_number, *context);
 }