serialization cleanup

yarn-project/circuit-types/src/contract_data.ts

@@ -5,7 +5,7 @@ import { EthAddress } from '@aztec/foundation/eth-address';
 import {
   BufferReader,
   numToInt32BE,
-  serializeBufferArrayToVector,
+  serializeArrayOfBufferableToVector,
   serializeToBuffer,
 } from '@aztec/foundation/serialize';
 import { ContractClass, ContractClassPublic, ContractInstanceWithAddress } from '@aztec/types/contracts';
@@ -158,7 +158,7 @@ export class ExtendedContractData {
     /** Public key hash of the contract. */
     public readonly publicKeyHash: Fr,
   ) {
-    this.bytecode = serializeBufferArrayToVector(publicFunctions.map(fn => fn.toBuffer()));
+    this.bytecode = serializeArrayOfBufferableToVector(publicFunctions.map(fn => fn.toBuffer()));
   }
 
   /**

yarn-project/circuit-types/src/sibling_path/sibling_path.ts

@@ -4,7 +4,7 @@ import {
   Tuple,
   assertLength,
   deserializeArrayFromVector,
-  serializeBufferArrayToVector,
+  serializeArrayOfBufferableToVector,
 } from '@aztec/foundation/serialize';
 import { Hasher } from '@aztec/types/interfaces';
 
@@ -61,7 +61,7 @@ export class SiblingPath<N extends number> {
    * @returns The buffer representation of this object.
    */
   public toBuffer(): Buffer {
-    return serializeBufferArrayToVector(this.data);
+    return serializeArrayOfBufferableToVector(this.data);
   }
 
   /**

yarn-project/circuit-types/src/tx_effect.ts

@@ -10,7 +10,7 @@ import {
 import { makeTuple } from '@aztec/foundation/array';
 import { padArrayEnd } from '@aztec/foundation/collection';
 import { sha256 } from '@aztec/foundation/crypto';
-import { BufferReader, Tuple } from '@aztec/foundation/serialize';
+import { BufferReader, Tuple, serializeArrayOfBufferableToVector } from '@aztec/foundation/serialize';
 
 export class TxEffect {
   constructor(
@@ -46,20 +46,6 @@ export class TxEffect {
   ) {}
 
   toBuffer(): Buffer {
-    // TODO(benesjan): move to foundation package?
-    const serializeAndPrefixWithUint8 = (
-      arr: {
-        /**
-         * Serialize to a buffer.
-         */
-        toBuffer: () => Buffer;
-      }[],
-    ) => {
-      const length = Buffer.alloc(1);
-      length.writeUInt8(arr.length);
-      return Buffer.concat([length, ...arr.map(x => x.toBuffer())]);
-    };
-
     const nonZeroNoteHashes = this.newNoteHashes.filter(h => !h.isZero());
     const nonZeroNullifiers = this.newNullifiers.filter(h => !h.isZero());
     const nonZeroL2ToL1Msgs = this.newL2ToL1Msgs.filter(h => !h.isZero());
@@ -68,11 +54,11 @@ export class TxEffect {
     const nonZeroContractData = this.contractData.filter(h => !h.isEmpty());
 
     return Buffer.concat([
-      serializeAndPrefixWithUint8(nonZeroNoteHashes),
-      serializeAndPrefixWithUint8(nonZeroNullifiers),
-      serializeAndPrefixWithUint8(nonZeroL2ToL1Msgs),
-      serializeAndPrefixWithUint8(nonZeroPublicDataWrites),
-      serializeAndPrefixWithUint8(nonZeroContractLeaves),
+      serializeArrayOfBufferableToVector(nonZeroNoteHashes, 1),
+      serializeArrayOfBufferableToVector(nonZeroNullifiers, 1),
+      serializeArrayOfBufferableToVector(nonZeroL2ToL1Msgs, 1),
+      serializeArrayOfBufferableToVector(nonZeroPublicDataWrites, 1),
+      serializeArrayOfBufferableToVector(nonZeroContractLeaves, 1),
       // We don't prefix the contract data with the length because we already have that info before contract leaves
       ...nonZeroContractData.map(x => x.toBuffer()),
       this.encryptedLogs.toBuffer(),

yarn-project/circuits.js/src/contract/public_bytecode.ts

@@ -2,7 +2,7 @@ import { FunctionSelector } from '@aztec/foundation/abi';
 import {
   BufferReader,
   numToInt32BE,
-  serializeBufferArrayToVector,
+  serializeArrayOfBufferableToVector,
   serializeToBuffer,
 } from '@aztec/foundation/serialize';
 import { ContractClass } from '@aztec/types/contracts';
@@ -14,7 +14,7 @@ import { FUNCTION_SELECTOR_NUM_BYTES } from '../constants.gen.js';
  * @remarks This function should no longer be necessary once we have a single bytecode per contract.
  */
 export function packBytecode(publicFns: ContractClass['publicFunctions']): Buffer {
-  return serializeBufferArrayToVector(
+  return serializeArrayOfBufferableToVector(
     publicFns.map(fn => serializeToBuffer(fn.selector, fn.isInternal, numToInt32BE(fn.bytecode.length), fn.bytecode)),
   );
 }

yarn-project/foundation/src/serialize/buffer_reader.test.ts

@@ -3,7 +3,7 @@ import { jest } from '@jest/globals';
 import { randomBytes } from '../crypto/index.js';
 import { Fq, Fr } from '../fields/fields.js';
 import { BufferReader } from './buffer_reader.js';
-import { serializeBufferArrayToVector } from './serialize.js';
+import { serializeArrayOfBufferableToVector } from './serialize.js';
 
 const ARRAY = Array.from(Array(32)).map((_, idx) => (idx % 2 === 0 ? 0 : 1));
 const BUFFER = Buffer.from(ARRAY);
@@ -64,7 +64,7 @@ describe('buffer reader', () => {
         uintBuf.writeUInt32BE(num, 0);
         return uintBuf;
       });
-      const uintArrVec = serializeBufferArrayToVector(uintBufArr);
+      const uintArrVec = serializeArrayOfBufferableToVector(uintBufArr);
       vectorBufferReader = new BufferReader(uintArrVec);
     });
 

yarn-project/foundation/src/serialize/buffer_reader.ts

@@ -162,7 +162,6 @@ export class BufferReader {
    * @param itemDeserializer - Object with 'fromBuffer' method to deserialize vector elements.
    * @returns An array of deserialized elements of type T.
    */
-  // TODO(benesjan): This name is quite inconsistent with readVector. Rename readVector?
   public readVectorUint8Prefix<T>(itemDeserializer: {
     /**
      * A method to deserialize data from a buffer.

yarn-project/foundation/src/serialize/serialize.ts

@@ -4,13 +4,22 @@ import { numToUInt32BE } from './free_funcs.js';
 
 /**
  * For serializing an array of fixed length buffers.
- * TODO move to foundation pkg.
- * @param arr - Array of buffers.
+ * @param arr - Array of bufferable.
+ * @param prefixLength - The length of the prefix (denominated in bytes).
  * @returns The serialized buffers.
  */
-export function serializeBufferArrayToVector(arr: Buffer[]): Buffer {
-  const lengthBuf = Buffer.alloc(4);
-  lengthBuf.writeUInt32BE(arr.length, 0);
+export function serializeArrayOfBufferableToVector(objs: Bufferable[], prefixLength = 4): Buffer {
+  const arr = serializeToBufferArray(objs);
+  let lengthBuf: Buffer;
+  if (prefixLength === 1) {
+    lengthBuf = Buffer.alloc(1);
+    lengthBuf.writeUInt8(arr.length, 0);
+  } else if (prefixLength === 4) {
+    lengthBuf = Buffer.alloc(4);
+    lengthBuf.writeUInt32BE(arr.length, 0);
+  } else {
+    throw new Error(`Unsupported prefix length. Got ${prefixLength}, expected 1 or 4`);
+  }
   return Buffer.concat([lengthBuf, ...arr]);
 }
 
@@ -37,8 +46,6 @@ type DeserializeFn<T> = (
  * @param vector - The vector to deserialize.
  * @param offset - The position in the vector to start deserializing from.
  * @returns Deserialized array and how many bytes we advanced by.
- *
- * TODO: move to foundation pkg.
  */
 export function deserializeArrayFromVector<T>(
   deserialize: DeserializeFn<T>,