Function getHlcFunctions

src/common/hlc.ts:30–115

(
  uniqueId?: Id,
  getNow: GetNow = Date.now,
)

};

export const getHlcFunctions: typeof getHlcFunctionsDecl = (
  uniqueId?: Id,
  getNow: GetNow = Date.now,
): [
  getNextHlc: () => Hlc,
  seenHlc: (remoteHlc: Hlc) => void,
  encodeHlc: (logicalTime: number, counter: number, clientId?: Id) => Hlc,
  decodeHlc: (hlc: Hlc) => [logicalTime: number, counter: number, clientId: Id],
  getLastLogicalTime: () => number,
  getLastCounter: () => number,
  getClientId: () => Id,
] => {
  let lastLogicalTime = 0;
  let lastCounter = -1;

  const thisClientId = ifNotUndefined(uniqueId, getClientIdFromUniqueId, () =>
    getUniqueId(5),
  ) as string;

  const getNextHlc = (): Hlc => {
    seenHlc();
    return encodeHlc(lastLogicalTime, ++lastCounter);
  };

  const seenHlc = (hlc?: Hlc): void => {
    const previousLogicalTime = lastLogicalTime;
    const [remoteLogicalTime, remoteCounter] =
      isUndefined(hlc) || hlc == EMPTY_STRING ? [0, 0] : decodeHlc(hlc);
    lastLogicalTime = mathMax(previousLogicalTime, remoteLogicalTime, getNow());
    lastCounter =
      lastLogicalTime == previousLogicalTime
        ? lastLogicalTime == remoteLogicalTime
          ? mathMax(lastCounter, remoteCounter)
          : lastCounter
        : lastLogicalTime == remoteLogicalTime
          ? remoteCounter
          : -1;
  };

  const encodeHlc = (logicalTime42: number, counter24: number, clientId?: Id) =>
    encode(logicalTime42 / SHIFT36) +
    encode(logicalTime42 / SHIFT30) +
    encode(logicalTime42 / SHIFT24) +
    encode(logicalTime42 / SHIFT18) +
    encode(logicalTime42 / SHIFT12) +
    encode(logicalTime42 / SHIFT6) +
    encode(logicalTime42) +
    encode(counter24 / SHIFT18) +
    encode(counter24 / SHIFT12) +
    encode(counter24 / SHIFT6) +
    encode(counter24) +
    (isUndefined(clientId) ? thisClientId : getClientIdFromUniqueId(clientId));

  const decodeHlc = (
    hlc16: Hlc,
  ): [logicalTime42: number, counter24: number, clientId: Id] => [
    decode(hlc16, 0) * SHIFT36 +
      decode(hlc16, 1) * SHIFT30 +