refactor: streamlined log processing

noir-projects/aztec-nr/aztec/src/discovery/mod.nr

@@ -3,6 +3,7 @@ use protocol_types::{address::AztecAddress, debug_log::debug_log};
 
 pub mod nonce_discovery;
 pub mod partial_notes;
+pub mod pending_tagged_log;
 pub mod private_logs;
 pub mod private_notes;
 

noir-projects/aztec-nr/aztec/src/discovery/pending_tagged_log.nr

@@ -0,0 +1,142 @@
+use protocol_types::{
+    address::AztecAddress,
+    constants::{MAX_NOTE_HASHES_PER_TX, PRIVATE_LOG_SIZE_IN_FIELDS},
+    hash::sha256_to_field,
+    traits::{Deserialize, Serialize},
+};
+
+// Base slot for the pending tagged log array to which the syncNotes oracle inserts found private logs.
+pub(crate) global PENDING_TAGGED_LOG_ARRAY_BASE_SLOT: Field = sha256_to_field(
+    "AZTEC_NR::PENDING_TAGGED_PENDING_TAGGED_LOG_ARRAY_BASE_SLOT".as_bytes(),
+);
+
+/// Represents a log as it is stored in the pending tagged log array to which the syncNotes oracle inserts found private log.
+#[derive(Deserialize, Serialize)]
+pub(crate) struct PendingTaggedLog {
+    pub log: BoundedVec<Field, PRIVATE_LOG_SIZE_IN_FIELDS>,
+    pub tx_hash: Field,
+    pub unique_note_hashes_in_tx: BoundedVec<Field, MAX_NOTE_HASHES_PER_TX>,
+    pub first_nullifier_in_tx: Field,
+    pub recipient: AztecAddress,
+    pub log_index_in_tx: Field,
+}
+
+mod test {
+    use crate::discovery::pending_tagged_log::PendingTaggedLog;
+    use protocol_types::{address::AztecAddress, traits::{FromField, Serialize}};
+
+    #[test]
+    unconstrained fn pending_tagged_log_serialization_matches_typescript() {
+        let log = BoundedVec::from_array([1, 2, 3]);
+        let tx_hash = 123;
+        let unique_note_hashes = BoundedVec::from_array([4, 5]);
+        let first_nullifier = 6;
+        let recipient = AztecAddress::from_field(789);
+        let log_index_in_tx = 10;
+        let pending_log = PendingTaggedLog {
+            log,
+            tx_hash,
+            unique_note_hashes_in_tx: unique_note_hashes,
+            first_nullifier_in_tx: first_nullifier,
+            recipient,
+            log_index_in_tx,
+        };
+
+        let serialized = pending_log.serialize();
+
+        // The following value was generated by `pending_tagged_log.test.ts`
+        // --> Run the test with AZTEC_GENERATE_TEST_DATA=1 flag to update test data.
+        let serialized_pending_tagged_log_from_typescript = [
+            0x0000000000000000000000000000000000000000000000000000000000000001,
+            0x0000000000000000000000000000000000000000000000000000000000000002,
+            0x0000000000000000000000000000000000000000000000000000000000000003,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000003,
+            0x000000000000000000000000000000000000000000000000000000000000007b,
+            0x0000000000000000000000000000000000000000000000000000000000000004,
+            0x0000000000000000000000000000000000000000000000000000000000000005,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000000,
+            0x0000000000000000000000000000000000000000000000000000000000000002,
+            0x0000000000000000000000000000000000000000000000000000000000000006,
+            0x0000000000000000000000000000000000000000000000000000000000000315,
+            0x000000000000000000000000000000000000000000000000000000000000000a,
+        ];
+
+        assert_eq(serialized, serialized_pending_tagged_log_from_typescript);
+    }
+}

noir-projects/aztec-nr/aztec/src/discovery/private_logs.nr

@@ -1,7 +1,11 @@
 use crate::{
+    capsules::CapsuleArray,
     discovery::{
-        ComputeNoteHashAndNullifier, MAX_LOG_CONTENT_LEN,
-        partial_notes::process_partial_note_private_log, PRIVATE_LOG_EXPANDED_METADATA_LEN,
+        ComputeNoteHashAndNullifier,
+        MAX_LOG_CONTENT_LEN,
+        partial_notes::process_partial_note_private_log,
+        pending_tagged_log::{PENDING_TAGGED_LOG_ARRAY_BASE_SLOT, PendingTaggedLog},
+        PRIVATE_LOG_EXPANDED_METADATA_LEN,
         private_notes::process_private_note_log,
     },
     encrypted_logs::{
@@ -19,7 +23,6 @@ use crate::{
 use protocol_types::{
     abis::event_selector::EventSelector,
     address::AztecAddress,
-    constants::{MAX_NOTE_HASHES_PER_TX, PRIVATE_LOG_SIZE_IN_FIELDS},
     debug_log::{debug_log, debug_log_format},
     traits::FromField,
 };
@@ -31,14 +34,31 @@ use crate::encrypted_logs::log_encryption::PRIVATE_LOG_PLAINTEXT_SIZE_IN_FIELDS;
 /// are stored in the PXE capsules so that `fetch_and_process_public_partial_note_completion_logs` can later search for
 /// public logs that will complete them.
 pub unconstrained fn fetch_and_process_private_tagged_logs<Env>(
-    _contract_address: AztecAddress,
-    _compute_note_hash_and_nullifier: ComputeNoteHashAndNullifier<Env>,
+    contract_address: AztecAddress,
+    compute_note_hash_and_nullifier: ComputeNoteHashAndNullifier<Env>,
 ) {
-    // We will eventually fetch tagged logs, decrypt and process them here, but for now we simply call the `syncNotes`
-    // oracle. This has PXE perform tag synchronization, log download, decryption, and finally calls to the the
-    // `process_log` contract function with the decrypted payload, which will in turn call `do_process_log` with a
-    // decrypted log, letting us continue the work outside of PXE.
-    sync_notes();
+    // We will eventually perform log discovery via tagging here, but for now we simply call the `syncNotes` oracle.
+    // This makes PXE synchronize tags, download logs and store the pending tagged logs in capsule array which are then
+    // retrieved and processed here.
+    sync_notes(PENDING_TAGGED_LOG_ARRAY_BASE_SLOT);
+
+    // Get logs from capsules
+    let logs =
+        CapsuleArray::<PendingTaggedLog>::at(contract_address, PENDING_TAGGED_LOG_ARRAY_BASE_SLOT);
+    let len = logs.len();
+
+    // We iterate over the logs in reverse order to avoid shifting elements.
+    let mut i = len;
+    while i > 0 {
+        i -= 1;
+
+        // Get and process each log
+        let log = logs.get(i);
+        process_log(contract_address, compute_note_hash_and_nullifier, log);
+
+        // Remove the log from the capsule array
+        logs.remove(i);
+    }
 }
 
 /// Processes a log's ciphertext by decrypting it and then searching the plaintext for private notes or partial notes.
@@ -50,21 +70,20 @@ pub unconstrained fn fetch_and_process_private_tagged_logs<Env>(
 ///
 /// Partial notes result in a pending partial note entry being stored in a PXE capsule, which will later be retrieved to
 /// search for the note's completion public log.
-pub unconstrained fn do_process_log<Env>(
+unconstrained fn process_log<Env>(
     contract_address: AztecAddress,
-    log: BoundedVec<Field, PRIVATE_LOG_SIZE_IN_FIELDS>,
-    tx_hash: Field,
-    unique_note_hashes_in_tx: BoundedVec<Field, MAX_NOTE_HASHES_PER_TX>,
-    first_nullifier_in_tx: Field,
-    log_index_in_tx: Field,
-    recipient: AztecAddress,
     compute_note_hash_and_nullifier: ComputeNoteHashAndNullifier<Env>,
+    pending_tagged_log: PendingTaggedLog,
 ) {
-    debug_log_format("Processing log with tag {0}", [log.get(0)]);
+    debug_log_format(
+        "Processing log with tag {0}",
+        [pending_tagged_log.log.get(0)],
+    );
+
+    // The tag is ignored for now.
+    let ciphertext = array::subbvec(pending_tagged_log.log, 1);
 
-    // The first field of the log is the tag, which we don't need right now, and the rest is all ciphertext.
-    let ciphertext = array::subbvec(log, 1);
-    let log_plaintext = AES128::decrypt_log(ciphertext, recipient);
+    let log_plaintext = AES128::decrypt_log(ciphertext, pending_tagged_log.recipient);
 
     // The first thing to do after decrypting the log is to determine what type of private log we're processing. We
     // have 3 log types: private note logs, partial note logs and event logs.
@@ -76,18 +95,23 @@ pub unconstrained fn do_process_log<Env>(
 
         process_private_note_log(
             contract_address,
-            tx_hash,
-            unique_note_hashes_in_tx,
-            first_nullifier_in_tx,
-            recipient,
+            pending_tagged_log.tx_hash,
+            pending_tagged_log.unique_note_hashes_in_tx,
+            pending_tagged_log.first_nullifier_in_tx,
+            pending_tagged_log.recipient,
             compute_note_hash_and_nullifier,
             log_metadata,
             log_content,
         );
     } else if log_type_id == PARTIAL_NOTE_PRIVATE_LOG_TYPE_ID {
         debug_log("Processing partial note private log");
 
-        process_partial_note_private_log(contract_address, recipient, log_metadata, log_content);
+        process_partial_note_private_log(
+            contract_address,
+            pending_tagged_log.recipient,
+            log_metadata,
+            log_content,
+        );
     } else if log_type_id == PRIVATE_EVENT_LOG_TYPE_ID {
         debug_log("Processing private event log");
 
@@ -96,14 +120,13 @@ pub unconstrained fn do_process_log<Env>(
 
         store_private_event_log(
             contract_address,
-            recipient,
+            pending_tagged_log.recipient,
             event_selector,
             log_content,
-            tx_hash,
-            log_index_in_tx,
+            pending_tagged_log.tx_hash,
+            pending_tagged_log.log_index_in_tx,
         );
     } else {
-        // TODO(#11569): handle events
         debug_log_format(
             "Unknown log type id {0} (probably belonging to an event log)",
             [log_type_id as Field],

noir-projects/aztec-nr/aztec/src/macros/aztec.nr

@@ -22,7 +22,6 @@ pub comptime fn aztec(m: Module) -> Quoted {
 
     let contract_library_method_compute_note_hash_and_nullifier =
         generate_contract_library_method_compute_note_hash_and_nullifier();
-    let process_log = generate_process_log();
     let note_exports = generate_note_exports();
     let public_dispatch = generate_public_dispatch(m);
     let sync_notes = generate_sync_notes();
@@ -31,7 +30,6 @@ pub comptime fn aztec(m: Module) -> Quoted {
         $note_exports
         $interface
         $contract_library_method_compute_note_hash_and_nullifier
-        $process_log
         $public_dispatch
         $sync_notes
     }
@@ -256,63 +254,6 @@ comptime fn generate_contract_library_method_compute_note_hash_and_nullifier() -
     }
 }
 
-comptime fn generate_process_log() -> Quoted {
-    // This mandatory function processes a log emitted by the contract. This is currently used to process private logs
-    // and perform message discovery, resulting in new private notes, partial notes and events.
-    // The bulk of the work of this function is done by aztec::discovery::do_process_log, so all we need to do is call
-    // that function.
-
-    // We'll produce the entire body of the function in one go and then insert it into the function.
-    let notes = NOTES.entries();
-
-    if notes.len() > 0 {
-        quote {
-            unconstrained fn process_log(
-                log_ciphertext: BoundedVec<Field, dep::aztec::protocol_types::constants::PRIVATE_LOG_SIZE_IN_FIELDS>,
-                tx_hash: Field,
-                unique_note_hashes_in_tx: BoundedVec<Field, dep::aztec::protocol_types::constants::MAX_NOTE_HASHES_PER_TX>,
-                first_nullifier_in_tx: Field,
-                log_index_in_tx: Field,
-                recipient: aztec::protocol_types::address::AztecAddress,
-            ) {
-                // Because this unconstrained function is injected after the contract is processed by the macros, it'll
-                // not be modified by the macros that alter unconstrained functions. As such, we need to manually inject
-                // the unconstrained execution context since it will not be available otherwise.
-                let context = dep::aztec::context::unconstrained_context::UnconstrainedContext::new();
-
-                // TODO(#10727): allow other contracts to process logs and deliver notes
-                let contract_address = context.this_address();
-
-                aztec::discovery::private_logs::do_process_log(
-                    contract_address,
-                    log_ciphertext,
-                    tx_hash,
-                    unique_note_hashes_in_tx,
-                    first_nullifier_in_tx,
-                    log_index_in_tx,
-                    recipient,
-                    _compute_note_hash_and_nullifier,
-                );
-            }
-        }
-    } else {
-        // Contracts with no notes still implement this function to avoid having special-casing, the implementation
-        // simply throws immediately.
-        quote {
-            unconstrained fn process_log(
-                _log_ciphertext: BoundedVec<Field, dep::aztec::protocol_types::constants::PRIVATE_LOG_SIZE_IN_FIELDS>,
-                _tx_hash: Field,
-                _unique_note_hashes_in_tx: BoundedVec<Field, dep::aztec::protocol_types::constants::MAX_NOTE_HASHES_PER_TX>,
-                _first_nullifier_in_tx: Field,
-                _log_index_in_tx: Field,
-                _recipient: aztec::protocol_types::address::AztecAddress,
-            ) {
-                panic(f"This contract does not use private notes")
-            }
-        }
-    }
-}
-
 comptime fn generate_note_exports() -> Quoted {
     let notes = NOTES.values();
     // Second value in each tuple is `note_packed_len` and that is ignored here because it's only used when