限流、并发与重复提交

const delays = [1000, 2000, 4000, 8000];

for (const delay of delays) {
  const response = await callLingganApi();
  if (response.ok) break;

  if (response.status !== 429 && response.status < 500) {
    throw new Error(await response.text());
  }

  const retryAfter = Number(response.headers.get('Retry-After'));
  const waitMs = Number.isFinite(retryAfter)
    ? retryAfter * 1000
    : delay + Math.floor(Math.random() * 500);

  await new Promise(resolve => setTimeout(resolve, waitMs));
}