fix: avoid Buffer.from copies

packages/api/src/beacon/server/beacon.ts

@@ -23,7 +23,7 @@ export function getRoutes(config: ChainForkConfig, api: ServerApi<Api>): ServerR
         const response = await api.getBlock(...reqSerializers.getBlock.parseReq(req));
         if (response instanceof Uint8Array) {
           // Fastify 3.x.x will automatically add header `Content-Type: application/octet-stream` if Buffer
-          return Buffer.from(response);
+          return Buffer.from(response.buffer, response.byteOffset, response.byteLength);
         } else {
           return returnTypes.getBlock.toJson(response);
         }
@@ -38,7 +38,7 @@ export function getRoutes(config: ChainForkConfig, api: ServerApi<Api>): ServerR
           const version = config.getForkName(slot);
           void res.header("Eth-Consensus-Version", version);
           // Fastify 3.x.x will automatically add header `Content-Type: application/octet-stream` if Buffer
-          return Buffer.from(response);
+          return Buffer.from(response.buffer, response.byteOffset, response.byteLength);
         } else {
           void res.header("Eth-Consensus-Version", response.version);
           return returnTypes.getBlockV2.toJson(response);

packages/api/src/beacon/server/debug.ts

@@ -24,7 +24,7 @@ export function getRoutes(config: ChainForkConfig, api: ServerApi<Api>): ServerR
         const response = await api.getState(...reqSerializers.getState.parseReq(req));
         if (response instanceof Uint8Array) {
           // Fastify 3.x.x will automatically add header `Content-Type: application/octet-stream` if Buffer
-          return Buffer.from(response);
+          return Buffer.from(response.buffer, response.byteOffset, response.byteLength);
         } else {
           return returnTypes.getState.toJson(response);
         }

packages/api/src/beacon/server/proof.ts

@@ -25,7 +25,7 @@ export function getRoutes(config: ChainForkConfig, api: ServerApi<Api>): ServerR
           response.set(leaves[i], i * 32);
         }
         // Fastify 3.x.x will automatically add header `Content-Type: application/octet-stream` if Buffer
-        return Buffer.from(response);
+        return Buffer.from(response.buffer, response.byteOffset, response.byteLength);
       },
     },
     getBlockProof: {
@@ -39,7 +39,7 @@ export function getRoutes(config: ChainForkConfig, api: ServerApi<Api>): ServerR
           response.set(leaves[i], i * 32);
         }
         // Fastify 3.x.x will automatically add header `Content-Type: application/octet-stream` if Buffer
-        return Buffer.from(response);
+        return Buffer.from(response.buffer, response.byteOffset, response.byteLength);
       },
     },
   };

packages/beacon-node/src/network/gossip/encoding.ts

@@ -58,7 +58,7 @@ export function msgIdFn(gossipTopicCache: GossipTopicCache, msg: Message): Uint8
     vec = [MESSAGE_DOMAIN_VALID_SNAPPY, intToBytes(msg.topic.length, 8), Buffer.from(msg.topic), msg.data];
   }
 
-  return Buffer.from(digest(Buffer.concat(vec))).subarray(0, 20);
+  return digest(Buffer.concat(vec)).subarray(0, 20);
 }
 
 export class DataTransformSnappy {

packages/beacon-node/src/util/sszBytes.ts

@@ -25,6 +25,10 @@ const SLOT_SIZE = 8;
 const ATTESTATION_DATA_SIZE = 128;
 const SIGNATURE_SIZE = 96;
 
+function toBuffer(x: Uint8Array): Buffer {
+  return Buffer.from(x.buffer, x.byteOffset, x.byteLength);
+}
+
 /**
  * Extract slot from attestation serialized bytes.
  * Return null if data is not long enough to extract slot.
@@ -59,9 +63,7 @@ export function getAttDataBase64FromAttestationSerialized(data: Uint8Array): Att
   }
 
   // base64 is a bit efficient than hex
-  return Buffer.from(data.slice(VARIABLE_FIELD_OFFSET, VARIABLE_FIELD_OFFSET + ATTESTATION_DATA_SIZE)).toString(
-    "base64"
-  );
+  return toBuffer(data.slice(VARIABLE_FIELD_OFFSET, VARIABLE_FIELD_OFFSET + ATTESTATION_DATA_SIZE)).toString("base64");
 }
 
 /**
@@ -150,7 +152,7 @@ export function getAttDataBase64FromSignedAggregateAndProofSerialized(data: Uint
   }
 
   // base64 is a bit efficient than hex
-  return Buffer.from(
+  return toBuffer(
     data.slice(SIGNED_AGGREGATE_AND_PROOF_SLOT_OFFSET, SIGNED_AGGREGATE_AND_PROOF_SLOT_OFFSET + ATTESTATION_DATA_SIZE)
   ).toString("base64");
 }

packages/reqresp/src/encoders/responseEncode.ts

@@ -3,6 +3,8 @@ import {encodeErrorMessage} from "../utils/index.js";
 import {ContextBytesType, ContextBytesFactory, MixedProtocol, Protocol, ResponseOutgoing} from "../types.js";
 import {RespStatus, RpcResponseStatusError} from "../interface.js";
 
+const SUCCESS_BUFFER = Buffer.from([RespStatus.SUCCESS]);
+
 /**
  * Yields byte chunks for a `<response>` with a zero response code `<result>`
  * ```bnf
@@ -24,7 +26,7 @@ export function responseEncodeSuccess(
       cbs.onChunk(chunkIndex++);
 
       // <result>
-      yield Buffer.from([RespStatus.SUCCESS]);
+      yield SUCCESS_BUFFER;
 
       // <context-bytes> - from altair
       const contextBytes = getContextBytes(protocol.contextBytes, chunk);

packages/reqresp/src/encodingStrategies/sszSnappy/encode.ts

@@ -15,7 +15,8 @@ export const writeSszSnappyPayload = encodeSszSnappy as (bytes: Uint8Array) => A
  */
 export async function* encodeSszSnappy(bytes: Buffer): AsyncGenerator<Buffer> {
   // MUST encode the length of the raw SSZ bytes, encoded as an unsigned protobuf varint
-  yield Buffer.from(varintEncode(bytes.length));
+  const varint = varintEncode(bytes.length);
+  yield Buffer.from(varint.buffer, varint.byteOffset, varint.byteLength);
 
   // By first computing and writing the SSZ byte length, the SSZ encoder can then directly
   // write the chunk contents to the stream. Snappy writer compresses frame by frame

packages/reqresp/src/utils/errorMessage.ts

@@ -1,4 +1,4 @@
-import {encodeSszSnappy} from "../encodingStrategies/sszSnappy/encode.js";
+import {writeSszSnappyPayload} from "../encodingStrategies/sszSnappy/encode.js";
 import {Encoding} from "../types.js";
 
 // ErrorMessage schema:
@@ -17,11 +17,11 @@ import {Encoding} from "../types.js";
  */
 export async function* encodeErrorMessage(errorMessage: string, encoding: Encoding): AsyncGenerator<Buffer> {
   const encoder = new TextEncoder();
-  const bytes = Buffer.from(encoder.encode(errorMessage).slice(0, 256));
+  const bytes = encoder.encode(errorMessage).slice(0, 256);
 
   switch (encoding) {
     case Encoding.SSZ_SNAPPY:
-      yield* encodeSszSnappy(bytes);
+      yield* writeSszSnappyPayload(bytes);
   }
 }
 

packages/state-transition/package.json

@@ -68,12 +68,9 @@
     "@lodestar/params": "^1.18.0",
     "@lodestar/types": "^1.18.0",
     "@lodestar/utils": "^1.18.0",
-    "bigint-buffer": "^1.1.5",
-    "buffer-xor": "^2.0.2"
-  },
-  "devDependencies": {
-    "@types/buffer-xor": "^2.0.0"
+    "bigint-buffer": "^1.1.5"
   },
+  "devDependencies": {},
   "keywords": [
     "ethereum",
     "eth-consensus",

packages/state-transition/src/block/processRandao.ts

@@ -1,4 +1,3 @@
-import xor from "buffer-xor";
 import {digest} from "@chainsafe/as-sha256";
 import {allForks} from "@lodestar/types";
 import {EPOCHS_PER_HISTORICAL_VECTOR} from "@lodestar/params";
@@ -28,6 +27,14 @@ export function processRandao(
   }
 
   // mix in RANDAO reveal
-  const randaoMix = xor(Buffer.from(getRandaoMix(state, epoch)), Buffer.from(digest(randaoReveal)));
+  const randaoMix = xor(getRandaoMix(state, epoch), digest(randaoReveal));
   state.randaoMixes.set(epoch % EPOCHS_PER_HISTORICAL_VECTOR, randaoMix);
 }
+
+function xor(a: Uint8Array, b: Uint8Array): Uint8Array {
+  const length = Math.min(a.length, b.length);
+  for (let i = 0; i < length; i++) {
+    a[i] = a[i] ^ b[i];
+  }
+  return a;
+}

packages/state-transition/src/cache/pubkeyCache.ts

@@ -23,7 +23,7 @@ function toMemoryEfficientHexStr(hex: Uint8Array | string): string {
     return hex;
   }
 
-  return Buffer.from(hex).toString("hex");
+  return Buffer.from(hex.buffer, hex.byteOffset, hex.byteLength).toString("hex");
 }
 
 export class PubkeyIndexMap {

packages/state-transition/src/util/shuffle.ts

@@ -101,7 +101,7 @@ function innerShuffleList(input: Shuffleable, seed: Bytes32, dir: boolean): void
 
   // Seed is always the first 32 bytes of the hash input, we never have to change this part of the buffer.
   const _seed = seed;
-  Buffer.from(_seed).copy(buf, 0, 0, _SHUFFLE_H_SEED_SIZE);
+  buf.set(_seed.subarray(0, _SHUFFLE_H_SEED_SIZE), 0);
 
   // initial values here are not used: overwritten first within the inner for loop.
   let source = seed; // just setting it to a Bytes32

packages/validator/src/repositories/metaDataRepository.ts

@@ -25,7 +25,7 @@ export class MetaDataRepository {
   }
 
   async setGenesisValidatorsRoot(genesisValidatorsRoot: Root): Promise<void> {
-    await this.db.put(this.encodeKey(GENESIS_VALIDATORS_ROOT), Buffer.from(genesisValidatorsRoot), this.dbReqOpts);
+    await this.db.put(this.encodeKey(GENESIS_VALIDATORS_ROOT), genesisValidatorsRoot, this.dbReqOpts);
   }
 
   async getGenesisTime(): Promise<UintNum64 | null> {
@@ -34,7 +34,7 @@ export class MetaDataRepository {
   }
 
   async setGenesisTime(genesisTime: UintNum64): Promise<void> {
-    await this.db.put(this.encodeKey(GENESIS_TIME), Buffer.from(ssz.UintNum64.serialize(genesisTime)), this.dbReqOpts);
+    await this.db.put(this.encodeKey(GENESIS_TIME), ssz.UintNum64.serialize(genesisTime), this.dbReqOpts);
   }
 
   private encodeKey(key: Uint8Array): Uint8Array {

packages/validator/src/slashingProtection/attestation/attestationByTargetRepository.ts

@@ -50,7 +50,7 @@ export class AttestationByTargetRepository {
     await this.db.batchPut(
       atts.map((att) => ({
         key: this.encodeKey(pubkey, att.targetEpoch),
-        value: Buffer.from(this.type.serialize(att)),
+        value: this.type.serialize(att),
       })),
       this.dbReqOpts
     );
@@ -62,7 +62,7 @@ export class AttestationByTargetRepository {
   }
 
   private encodeKey(pubkey: BLSPubkey, targetEpoch: Epoch): Uint8Array {
-    return encodeKey(this.bucket, Buffer.concat([Buffer.from(pubkey), intToBytes(BigInt(targetEpoch), uintLen, "be")]));
+    return encodeKey(this.bucket, Buffer.concat([pubkey, intToBytes(BigInt(targetEpoch), uintLen, "be")]));
   }
 
   private decodeKey(key: Uint8Array): {pubkey: BLSPubkey; targetEpoch: Epoch} {

packages/validator/src/slashingProtection/attestation/attestationLowerBoundRepository.ts

@@ -35,10 +35,10 @@ export class AttestationLowerBoundRepository {
   }
 
   async set(pubkey: BLSPubkey, value: SlashingProtectionLowerBound): Promise<void> {
-    await this.db.put(this.encodeKey(pubkey), Buffer.from(this.type.serialize(value)), this.dbReqOpts);
+    await this.db.put(this.encodeKey(pubkey), this.type.serialize(value), this.dbReqOpts);
   }
 
   private encodeKey(pubkey: BLSPubkey): Uint8Array {
-    return encodeKey(this.bucket, Buffer.from(pubkey));
+    return encodeKey(this.bucket, pubkey);
   }
 }

packages/validator/src/slashingProtection/block/blockBySlotRepository.ts

@@ -54,7 +54,7 @@ export class BlockBySlotRepository {
     await this.db.batchPut(
       blocks.map((block) => ({
         key: this.encodeKey(pubkey, block.slot),
-        value: Buffer.from(this.type.serialize(block)),
+        value: this.type.serialize(block),
       })),
       this.dbReqOpts
     );
@@ -66,7 +66,7 @@ export class BlockBySlotRepository {
   }
 
   private encodeKey(pubkey: BLSPubkey, slot: Slot): Uint8Array {
-    return encodeKey(this.bucket, Buffer.concat([Buffer.from(pubkey), intToBytes(BigInt(slot), uintLen, "be")]));
+    return encodeKey(this.bucket, Buffer.concat([pubkey, intToBytes(BigInt(slot), uintLen, "be")]));
   }
 
   private decodeKey(key: Uint8Array): {pubkey: BLSPubkey; slot: Slot} {

packages/validator/src/slashingProtection/minMaxSurround/distanceStoreRepository.ts

@@ -45,13 +45,13 @@ class SpanDistanceRepository {
     await this.db.batchPut(
       values.map((value) => ({
         key: this.encodeKey(pubkey, value.source),
-        value: Buffer.from(this.type.serialize(value.distance)),
+        value: this.type.serialize(value.distance),
       })),
       this.dbReqOpts
     );
   }
 
   private encodeKey(pubkey: BLSPubkey, epoch: Epoch): Uint8Array {
-    return encodeKey(this.bucket, Buffer.concat([Buffer.from(pubkey), intToBytes(BigInt(epoch), 8, "be")]));
+    return encodeKey(this.bucket, Buffer.concat([pubkey, intToBytes(BigInt(epoch), 8, "be")]));
   }
 }

yarn.lock

@@ -2836,13 +2836,6 @@
   resolved "https://registry.yarnpkg.com/@types/argparse/-/argparse-1.0.38.tgz#a81fd8606d481f873a3800c6ebae4f1d768a56a9"
   integrity sha512-ebDJ9b0e702Yr7pWgB0jzm+CX4Srzz8RcXtLJDJB+BSccqMa36uyH/zUsSYao5+BD1ytv3k3rPYCq4mAE1hsXA==
 
-"@types/buffer-xor@^2.0.0":
-  version "2.0.2"
-  resolved "https://registry.yarnpkg.com/@types/buffer-xor/-/buffer-xor-2.0.2.tgz#d8c463583b8fbb322ea824562dc78a0c3cea2ca6"
-  integrity sha512-OqdCua7QCTupPnJgmyGJUpxWgbuOi0IMIVslXTSePS2o+qDrDB6f2Pg44zRyqhUA5GbFAf39U8z0+mH4WG0fLQ==
-  dependencies:
-    "@types/node" "*"
-
 "@types/cacheable-request@^6.0.1":
   version "6.0.3"
   resolved "https://registry.yarnpkg.com/@types/cacheable-request/-/cacheable-request-6.0.3.tgz#a430b3260466ca7b5ca5bfd735693b36e7a9d183"
@@ -4461,13 +4454,6 @@ buffer-xor@^1.0.3:
   resolved "https://registry.npmjs.org/buffer-xor/-/buffer-xor-1.0.3.tgz"
   integrity sha1-JuYe0UIvtw3ULm42cp7VHYVf6Nk=
 
-buffer-xor@^2.0.2:
-  version "2.0.2"
-  resolved "https://registry.npmjs.org/buffer-xor/-/buffer-xor-2.0.2.tgz"
-  integrity sha512-eHslX0bin3GB+Lx2p7lEYRShRewuNZL3fUl4qlVJGGiwoPGftmt8JQgk2Y9Ji5/01TnVDo33E5b5O3vUB1HdqQ==
-  dependencies:
-    safe-buffer "^5.1.1"
-
 buffer@4.9.2, buffer@^4.3.0:
   version "4.9.2"
   resolved "https://registry.npmjs.org/buffer/-/buffer-4.9.2.tgz"