crc64

crc64_be.js

// ref: https://github.com/torvalds/linux/blob/master/lib/crc64.c#L51
function crc64(str) {
  const CRC64_ECMA182_POLY = 0x42f0e1eba9ea3693n

  // CRC64 lookup table
  const crc64Table = []

  for (let i = 0n; i < 256n; i++) {
    let crc = 0n
    let c = i << 56n

    for (let j = 0n; j < 8n; j++) {
      if (BigInt(crc ^ c) & 0x8000000000000000n)
        crc = (crc << 1n) ^ CRC64_ECMA182_POLY
      else crc <<= 1n
      c <<= 1n
    }

    crc64Table[i] = crc & 0xffffffffffffffffn
  }

  //   console.log(crc64Table.map((crc) => crc.toString(16)))

  let crc = BigInt(0xffffffffffffffff)

  for (let i = 0; i < str.length; i++) {
    const byte = str.charCodeAt(i)
    const crcIdx = ((crc >> 56n) ^ BigInt(byte)) & 0xffn
    crc = (crc << 8n) ^ crc64Table[Number(crcIdx)]
  }

  return crc & 0xffffffffffffffffn
}

const input = 'abcdef'
const crc = crc64(input).toString(16)
console.log(crc)

NOTE: I am not sure if its the version of Webpack I was using but I had to change all the numbers with the 'n' suffix to use the BigInt constructor ie BigInt(8)

NOTE: I am not sure if its the version of Webpack I was using but I had to change all the numbers with the 'n' suffix to use the BigInt constructor ie BigInt(8)

Hello, you may need to use https://babeljs.io/docs/babel-plugin-syntax-bigint to support the 'n' suffix syntax.

Thanks for the Tip. I would rather make a slight change to the code than have to introduce yet another step to the "build" process.