Function updateV1State

src/v1.ts:93–143

(state: V1State, now: number, rnds: Uint8Array)

// (Private!)  Do not use.  This method is only exported for testing purposes
// and may change without notice.
export function updateV1State(state: V1State, now: number, rnds: Uint8Array) {
  state.msecs ??= -Infinity;
  state.nsecs ??= 0;

  // Update timestamp
  if (now === state.msecs) {
    // Same msec-interval = simulate higher clock resolution by bumping `nsecs`
    // https://www.rfc-editor.org/rfc/rfc9562.html#section-6.1-2.6
    state.nsecs++;

    // Check for `nsecs` overflow (nsecs is capped at 10K intervals / msec)
    if (state.nsecs >= 10000) {
      // Prior to uuid@11 this would throw an error, however the RFCs allow for
      // changing the node in this case.  This slightly breaks monotonicity at
      // msec granularity, but that's not a significant concern.
      // https://www.rfc-editor.org/rfc/rfc9562.html#section-6.1-2.16
      state.node = undefined;
      state.nsecs = 0;
    }
  } else if (now > state.msecs) {
    // Reset nsec counter when clock advances to a new msec interval
    state.nsecs = 0;
  } else if (now < state.msecs) {
    // Handle clock regression
    // https://www.rfc-editor.org/rfc/rfc9562.html#section-6.1-2.7
    //
    // Note: Unsetting node here causes both it and clockseq to be randomized,
    // below.
    state.node = undefined;
  }

  // Init node and clock sequence (do this after timestamp update which may
  // reset the node) https://www.rfc-editor.org/rfc/rfc9562.html#section-5.1-7
  //
  // Note:
  if (!state.node) {
    state.node = rnds.slice(10, 16);

    // Set multicast bit
    // https://www.rfc-editor.org/rfc/rfc9562.html#section-6.10-3
    state.node[0] |= 0x01; // Set multicast bit

    // Clock sequence must be randomized
    // https://www.rfc-editor.org/rfc/rfc9562.html#section-5.1-8
    state.clockseq = ((rnds[8] << 8) | rnds[9]) & 0x3fff;
  }

  state.msecs = now;

  return state;
}

function v1Bytes(
  rnds: Uint8Array,