feat: make serialized objects Uint8Array instead of Buffer

[matthewkeil]

@nflaig pointed out that the return types are buffer not uint8array. Putting this up in case we should move to uint8array.

After this and the bls package are published remove this cast in lodestar tests
ChainSafe/lodestar#6616 (comment)

[github-actions]

Performance Report

✔️ no performance regression detected

Full benchmark results

Benchmark suite	Current: ab72fdd	Previous: -	Ratio
PublicKey serialization	1.1480 us/op
PublicKey deserialize	22.325 us/op
PublicKey deserialize and validate - 1 keys	83.414 us/op
PublicKey deserialize and validate - 100 keys	8.2647 ms/op
PublicKey deserialize and validate - 10000 keys	830.42 ms/op
SecretKey.fromKeygen	3.5200 us/op
SecretKey serialization	1.1440 us/op
SecretKey deserialization	1.5750 us/op
SecretKey.toPublicKey	138.10 us/op
SecretKey.sign	531.13 us/op
Signature serialization	1.2890 us/op
Signature deserialize	44.168 us/op
Signatures deserialize and validate - 1 sets	120.23 us/op
Signatures deserialize and validate - 100 sets	11.960 ms/op
Signatures deserialize and validate - 10000 sets	1.1990 s/op
aggregatePublicKeys - 1 sets	2.4350 us/op
aggregatePublicKeys - 8 sets	10.579 us/op
aggregatePublicKeys - 32 sets	38.064 us/op
aggregatePublicKeys - 128 sets	148.63 us/op
aggregatePublicKeys - 256 sets	296.60 us/op
aggregateSignatures - 1 sets	4.2700 us/op
aggregateSignatures - 8 sets	23.864 us/op
aggregateSignatures - 32 sets	91.174 us/op
aggregateSignatures - 128 sets	361.04 us/op
aggregateSignatures - 256 sets	722.40 us/op
aggregateVerify - 1 sets	1.5944 ms/op
aggregateVerify - 8 sets	5.7591 ms/op
aggregateVerify - 32 sets	20.428 ms/op
aggregateVerify - 128 sets	79.127 ms/op
aggregateVerify - 256 sets	157.46 ms/op
verifyMultipleAggregateSignatures - 1 sets	1.6362 ms/op
verifyMultipleAggregateSignatures - 8 sets	6.1863 ms/op
verifyMultipleAggregateSignatures - 32 sets	22.059 ms/op
verifyMultipleAggregateSignatures - 128 sets	85.633 ms/op
verifyMultipleAggregateSignatures - 256 sets	170.49 ms/op
Same message - 1 sets	1.7092 ms/op
Same message - 8 sets	2.5784 ms/op
Same message - 32 sets	5.5302 ms/op
Same message - 128 sets	17.351 ms/op
Same message - 256 sets	33.089 ms/op
libuv multithreading - addVerificationRandomness true	20.672 s/op
libuv multithreading - addVerificationRandomness false	20.674 s/op

by benchmarkbot/action

[matthewkeil]

There is something very odd with how Napi is returning Uint8Array from the constructor.... I am returning Uint8Array from the native side and the __proto__ shows that it inherits from Uint8Array however the toString method is the Buffer.prototype.toString that allows three parameters.... and they work. Can change the encoding. But only works on some platform/version combos.... sigh...

    describe("serialize", () => {
      it.only("should serialize the key to Uint8Array", () => {
        const serialized = key.serialize();
        console.log(serialized.__proto__);
        console.log(serialized.toString.length);
        expect(serialized).to.be.instanceof(Buffer);
      });
    });

❯ yarn test:unit
yarn run v1.22.21
$ mocha test/unit/**/*.test.ts

  SecretKey
    instance methods
      serialize
Uint8Array {
  readBigUInt64LE: [Function: readBigUInt64LE],
  readBigUInt64BE: [Function: readBigUInt64BE],
  readBigUint64LE: [Function: readBigUInt64LE],
  readBigUint64BE: [Function: readBigUInt64BE],
  readBigInt64LE: [Function: readBigInt64LE],
  readBigInt64BE: [Function: readBigInt64BE],
  writeBigUInt64LE: [Function: writeBigUInt64LE],
  writeBigUInt64BE: [Function: writeBigUInt64BE],
  writeBigUint64LE: [Function: writeBigUInt64LE],
  writeBigUint64BE: [Function: writeBigUInt64BE],
  writeBigInt64LE: [Function: writeBigInt64LE],
  writeBigInt64BE: [Function: writeBigInt64BE],
  readUIntLE: [Function: readUIntLE],
  readUInt32LE: [Function: readUInt32LE],
  readUInt16LE: [Function: readUInt16LE],
  readUInt8: [Function: readUInt8],
  readUIntBE: [Function: readUIntBE],
  readUInt32BE: [Function: readUInt32BE],
  readUInt16BE: [Function: readUInt16BE],
  readUintLE: [Function: readUIntLE],
  readUint32LE: [Function: readUInt32LE],
  readUint16LE: [Function: readUInt16LE],
  readUint8: [Function: readUInt8],
  readUintBE: [Function: readUIntBE],
  readUint32BE: [Function: readUInt32BE],
  readUint16BE: [Function: readUInt16BE],
  readIntLE: [Function: readIntLE],
  readInt32LE: [Function: readInt32LE],
  readInt16LE: [Function: readInt16LE],
  readInt8: [Function: readInt8],
  readIntBE: [Function: readIntBE],
  readInt32BE: [Function: readInt32BE],
  readInt16BE: [Function: readInt16BE],
  writeUIntLE: [Function: writeUIntLE],
  writeUInt32LE: [Function: writeUInt32LE],
  writeUInt16LE: [Function: writeUInt16LE],
  writeUInt8: [Function: writeUInt8],
  writeUIntBE: [Function: writeUIntBE],
  writeUInt32BE: [Function: writeUInt32BE],
  writeUInt16BE: [Function: writeUInt16BE],
  writeUintLE: [Function: writeUIntLE],
  writeUint32LE: [Function: writeUInt32LE],
  writeUint16LE: [Function: writeUInt16LE],
  writeUint8: [Function: writeUInt8],
  writeUintBE: [Function: writeUIntBE],
  writeUint32BE: [Function: writeUInt32BE],
  writeUint16BE: [Function: writeUInt16BE],
  writeIntLE: [Function: writeIntLE],
  writeInt32LE: [Function: writeInt32LE],
  writeInt16LE: [Function: writeInt16LE],
  writeInt8: [Function: writeInt8],
  writeIntBE: [Function: writeIntBE],
  writeInt32BE: [Function: writeInt32BE],
  writeInt16BE: [Function: writeInt16BE],
  readFloatLE: [Function: readFloatForwards],
  readFloatBE: [Function: readFloatBackwards],
  readDoubleLE: [Function: readDoubleForwards],
  readDoubleBE: [Function: readDoubleBackwards],
  writeFloatLE: [Function: writeFloatForwards],
  writeFloatBE: [Function: writeFloatBackwards],
  writeDoubleLE: [Function: writeDoubleForwards],
  writeDoubleBE: [Function: writeDoubleBackwards],
  asciiSlice: [Function: asciiSlice],
  base64Slice: [Function: base64Slice],
  base64urlSlice: [Function: base64urlSlice],
  latin1Slice: [Function: latin1Slice],
  hexSlice: [Function: hexSlice],
  ucs2Slice: [Function: ucs2Slice],
  utf8Slice: [Function: utf8Slice],
  asciiWrite: [Function: asciiWrite],
  base64Write: [Function: base64Write],
  base64urlWrite: [Function: base64urlWrite],
  latin1Write: [Function: latin1Write],
  hexWrite: [Function: hexWrite],
  ucs2Write: [Function: ucs2Write],
  utf8Write: [Function: utf8Write],
  parent: [Getter],
  offset: [Getter],
  copy: [Function: copy],
  toString: [Function: toString],
  equals: [Function: equals],
  inspect: [Function: inspect],
  compare: [Function: compare],
  indexOf: [Function: indexOf],
  lastIndexOf: [Function: lastIndexOf],
  includes: [Function: includes],
  fill: [Function: fill],
  write: [Function: write],
  toJSON: [Function: toJSON],
  subarray: [Function: subarray],
  slice: [Function: slice],
  swap16: [Function: swap16],
  swap32: [Function: swap32],
  swap64: [Function: swap64],
  toLocaleString: [Function: toString],
  [Symbol(nodejs.util.inspect.custom)]: [Function: inspect]
}
3
        ✓ should serialize the key to Uint8Array


  1 passing (5ms)

✨  Done in 1.10s.

Returning Buffer does not change anything...

[nflaig]

LGTM