resolve-local-event-broker/es/publisher-server/core/get-next-cursor.js

The reSolve framework's event broker for applications on a local machine.

const split2RegExp = /.{1,2}(?=(.{2})+(?!.))|.{1,2}$/g;

const getNextCursor = (prevCursor, events) => {
  const cursorBuffer = prevCursor != null ? Buffer.from(prevCursor, 'base64') : Buffer.alloc(1536, 0);
  const vectorConditions = [];

  for (let i = 0; i < cursorBuffer.length / 6; i++) {
    vectorConditions.push(cursorBuffer.slice(i * 6, (i + 1) * 6).toString('hex'));
  }

  for (const event of events) {
    const {
      threadId,
      threadCounter
    } = event;
    const oldThreadCounter = parseInt(vectorConditions[threadId], 16);
    vectorConditions[threadId] = Math.max(threadCounter + 1, oldThreadCounter).toString(16).padStart(12, '0');
  }

  const nextConditionsBuffer = Buffer.alloc(1536);
  let byteIndex = 0;

  for (const threadCounter of vectorConditions) {
    const threadCounterBytes = threadCounter.match(split2RegExp);

    for (const byteHex of threadCounterBytes) {
      nextConditionsBuffer[byteIndex++] = Buffer.from(byteHex, 'hex')[0];
    }
  }

  return nextConditionsBuffer.toString('base64');
};

export default getNextCursor;
//# sourceMappingURL=get-next-cursor.js.map