feat: add batch is block in archive oracle (#24634)

Adds an oracle to check whether a collection of block hashes is present
in the archiver tree as of a given block. An upstream port of:
aztec-labs-eng/oxide#257

Note: I considered making this batch call return something more
"interesting" than existence booleans (such as MembershipWitnesses), but
that would potentially be heavy over the wire and there's no current
evidence of it being needed. We can add a new oracle for that if turns
out to be useful in the future.

Closes F-810

Author: mverzilli

noir-projects/aztec-nr/aztec/src/oracle/get_membership_witness.nr

@@ -1,8 +1,11 @@
-use crate::protocol::{
-    abis::block_header::BlockHeader,
-    constants::{ARCHIVE_HEIGHT, NOTE_HASH_TREE_HEIGHT},
-    merkle_tree::MembershipWitness,
-    traits::Hash,
+use crate::{
+    ephemeral::EphemeralArray,
+    protocol::{
+        abis::block_header::BlockHeader,
+        constants::{ARCHIVE_HEIGHT, NOTE_HASH_TREE_HEIGHT},
+        merkle_tree::MembershipWitness,
+        traits::Hash,
+    },
 };
 
 #[oracle(aztec_utl_getNoteHashMembershipWitness)]
@@ -17,6 +20,12 @@ unconstrained fn get_block_hash_membership_witness_oracle(
     block_hash: Field,
 ) -> Option<MembershipWitness<ARCHIVE_HEIGHT>> {}
 
+#[oracle(aztec_utl_areBlockHashesInArchive)]
+unconstrained fn are_block_hashes_in_archive_oracle(
+    anchor_block_hash: Field,
+    block_hashes: EphemeralArray<Field>,
+) -> EphemeralArray<bool> {}
+
 // Note: get_nullifier_membership_witness function is implemented in get_nullifier_membership_witness.nr
 
 /// Returns a membership witness for a `note_hash` in the note hash tree whose root is defined in
@@ -53,6 +62,15 @@ pub unconstrained fn get_maybe_block_hash_membership_witness(
     get_block_hash_membership_witness_oracle(anchor_block_hash, block_hash)
 }
 
+/// Returns whether each block hash is present in the archive tree whose root is defined in `anchor_block_header`.
+pub unconstrained fn are_block_hashes_in_archive(
+    anchor_block_header: BlockHeader,
+    block_hashes: EphemeralArray<Field>,
+) -> EphemeralArray<bool> {
+    let anchor_block_hash = anchor_block_header.hash();
+    are_block_hashes_in_archive_oracle(anchor_block_hash, block_hashes)
+}
+
 mod test {
     use crate::history::test::{create_note, NOTE_CREATED_AT};
     use crate::note::note_interface::NoteHash;

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

@@ -99,7 +99,12 @@ pub mod get_nullifier_membership_witness;
     ],
 )]
 pub mod get_public_data_witness;
-#[generate_oracle_tests]
+#[generate_oracle_tests_excluding(
+    @[
+        // TODO: cover once the test resolver can serve EphemeralArray contents.
+        quote { are_block_hashes_in_archive_oracle },
+    ],
+)]
 pub mod get_membership_witness;
 #[generate_oracle_tests]
 pub mod keys;

noir-projects/aztec-nr/aztec/src/oracle/version.nr

@@ -11,7 +11,7 @@
 /// immediately if AZTEC_NR_MINOR > PXE_MINOR because if a contract is updated to use a newer Aztec.nr dependency
 /// without actually using any of the new oracles then there is no reason to throw.
 pub global ORACLE_VERSION_MAJOR: Field = 30;
-pub global ORACLE_VERSION_MINOR: Field = 6;
+pub global ORACLE_VERSION_MINOR: Field = 7;
 
 /// Asserts that the version of the oracle is compatible with the version expected by the contract.
 pub fn assert_compatible_oracle_version() {

yarn-project/pxe/src/contract_function_simulator/oracle/oracle_registry.ts

@@ -141,6 +141,14 @@ export const ORACLE_REGISTRY = {
     returnType: OPTION(MEMBERSHIP_WITNESS(ARCHIVE_HEIGHT)),
   }),
 
+  aztec_utl_areBlockHashesInArchive: makeEntry({
+    params: [
+      { name: 'anchorBlockHash', type: BLOCK_HASH },
+      { name: 'blockHashes', type: EPHEMERAL_ARRAY(BLOCK_HASH) },
+    ],
+    returnType: EPHEMERAL_ARRAY(BOOL),
+  }),
+
   aztec_utl_getNullifierMembershipWitness: makeEntry({
     params: [
       { name: 'blockHash', type: BLOCK_HASH },

yarn-project/pxe/src/contract_function_simulator/oracle/utility_execution.test.ts

@@ -741,6 +741,27 @@ describe('Utility Execution test suite', () => {
         expect(aztecNode.getBlockHashMembershipWitness).toHaveBeenCalledTimes(1);
       });
 
+      it('returns aligned archive-membership booleans for block hash batches', async () => {
+        const service = new EphemeralArrayService();
+        const oracle = makeOracle({ scopes: [scope] });
+        const referenceBlockHash = await anchorBlockHeader.hash();
+        const presentBlockHash = BlockHash.random();
+        const missingBlockHash = BlockHash.random();
+        const witness = MembershipWitness.empty(ARCHIVE_HEIGHT);
+
+        aztecNode.getBlockHashMembershipWitness.mockImplementation((_referenceBlockHash, blockHash) =>
+          Promise.resolve(blockHash.equals(presentBlockHash) ? witness : undefined),
+        );
+
+        const result = await oracle.areBlockHashesInArchive(
+          referenceBlockHash,
+          EphemeralArray.fromValues(service, [presentBlockHash, missingBlockHash, presentBlockHash]),
+        );
+
+        expect(result.readAll(service)).toEqual([true, false, true]);
+        expect(aztecNode.getBlockHashMembershipWitness).toHaveBeenCalledTimes(2);
+      });
+
       it('reuses public storage reads within a utility execution', async () => {
         const oracle = makeOracle({ scopes: [scope] });
         const blockHash = await anchorBlockHeader.hash();

yarn-project/pxe/src/contract_function_simulator/oracle/utility_execution_oracle.ts

@@ -273,6 +273,22 @@ export class UtilityExecutionOracle implements IMiscOracle, IUtilityExecutionOra
     return witness ? Option.some(witness) : Option.none();
   }
 
+  /** Returns whether each block hash is present in the archive tree at the referenced block. */
+  public async areBlockHashesInArchive(
+    referenceBlockHash: BlockHash,
+    blockHashes: EphemeralArray<BlockHash>,
+  ): Promise<EphemeralArray<boolean>> {
+    const hashes = blockHashes.readAll(this.ephemeralArrayService);
+    const memberships = await this.#queryWithBlockHashNotAfterAnchor(referenceBlockHash, () =>
+      Promise.all(
+        hashes.map(blockHash =>
+          this.aztecNodeReadCache.getBlockHashMembershipWitness(referenceBlockHash, blockHash).then(Boolean),
+        ),
+      ),
+    );
+    return EphemeralArray.fromValues(this.ephemeralArrayService, memberships);
+  }
+
   /**
    * Returns a nullifier membership witness for a given nullifier at a given block.
    * @param blockHash - The block hash at which to get the index.

yarn-project/pxe/src/oracle_version.ts

@@ -11,12 +11,12 @@
 /// if AZTEC_NR_MINOR > PXE_MINOR because if a contract is updated to use a newer Aztec.nr dependency without actually
 /// using any of the new oracles then there is no reason to throw.
 export const ORACLE_VERSION_MAJOR = 30;
-export const ORACLE_VERSION_MINOR = 6;
+export const ORACLE_VERSION_MINOR = 7;
 
 /// This hash is computed from the `ORACLE_REGISTRY` declaration (each oracle's name, ordered parameter names and
 /// types, and return type) and is used to detect when the oracle interface changes. When it does, you need to either:
 /// - increment `ORACLE_VERSION_MAJOR` and reset `ORACLE_VERSION_MINOR` to zero if the change is breaking, or
 /// - increment only `ORACLE_VERSION_MINOR` if the change is additive (a new oracle was added).
 ///
 /// These constants must be kept in sync between this file and `noir-projects/aztec-nr/aztec/src/oracle/version.nr`.
-export const ORACLE_INTERFACE_HASH = '6094994f539407001d2adce5b6a8792c08ef645ee39813e32390f6208e78bc16';
+export const ORACLE_INTERFACE_HASH = '416b0e7d3e6dca5803ebe2a65ea93f1e79759dc39ef8ec4c52eeba5e2b0f3fca';

yarn-project/txe/src/rpc_translator.ts

@@ -572,6 +572,16 @@ export class RPCTranslator {
     });
   }
 
+  // eslint-disable-next-line camelcase
+  aztec_utl_areBlockHashesInArchive(...inputs: ForeignCallArgs) {
+    return callTxeHandler({
+      oracle: 'aztec_utl_areBlockHashesInArchive',
+      inputs,
+      handler: ([anchorBlockHash, blockHashes]) =>
+        this.handlerAsUtility().areBlockHashesInArchive(anchorBlockHash, blockHashes),
+    });
+  }
+
   // eslint-disable-next-line camelcase
   aztec_utl_getLowNullifierMembershipWitness(...inputs: ForeignCallArgs) {
     return callTxeHandler({