Function x64hash128

javascript/packages/core/lib/murmurHash3.ts:181–289

(
  buf: Uint8Array = new Uint8Array(0),
  state: u32 = 0x0,
)

export function x64hash128(
  buf: Uint8Array = new Uint8Array(0),
  state: u32 = 0x0,
): DataView {
  let h1: u64;
  let h2: u64;
  let i: number;
  let len: number;
  if (typeof state === 'number') {
    h1 = [0x0, state];
    h2 = [0x0, state];
    i = 0;
    len = 0;
  } else {
    ({ h1, h2, len } = state as x64hash128State);
    const rem = (state as x64hash128State).rem;
    
    if (rem.byteLength === 0) {
      i = 0;
    } else if (rem.byteLength + buf.byteLength >= 16) {
      len += 16;
      i = 16 - rem.byteLength;
      
      const blk = new Uint8Array(16);
      const dtv = new DataView(blk.buffer);
      blk.set(rem);
      blk.set(buf.subarray(0, i), rem.byteLength);
      
      [h1, h2] = x64mix128(
        h1, h2,
        [dtv.getUint32(4, true), dtv.getUint32(0, true)],
        [dtv.getUint32(12, true), dtv.getUint32(8, true)],
      );
    } else {
      const newBuf = new Uint8Array(buf.byteLength + rem.byteLength);
      newBuf.set(rem);
      newBuf.set(buf, rem.byteLength);
      buf = newBuf;
      i = 0;
    }
  }
  
  const dtv = new DataView(buf.buffer, buf.byteOffset);
  const remainder = (buf.byteLength - i) % 16;
  const bytes = buf.byteLength - i - remainder;
  len += bytes;
  
  for (; i < bytes; i += 16) {
    [h1, h2] = x64mix128(
      h1, h2,
      [dtv.getUint32(i + 4, true), dtv.getUint32(i, true)],
      [dtv.getUint32(i + 12, true), dtv.getUint32(i + 8, true)],
    );
  }
  
  {
    len += remainder;
    let k1: u64 = [0x0, 0x0];