Function shouldRevalidateCache

CesiumAsync/src/CachingAssetAccessor.cpp:344–354

namespace {

bool shouldRevalidateCache(const CacheItem& cacheItem) {
  std::optional<ResponseCacheControl> cacheControl =
      ResponseCacheControl::parseFromResponseHeaders(
          cacheItem.cacheResponse.headers);
  if (cacheControl && cacheControl->noCache())
    return true;

  // Always revalidate if cache is stale. We always assume online scenarios.
  // A must-revalidate directive doesn't change this logic.
  return isCacheStale(cacheItem);
}

bool isCacheStale(const CacheItem& cacheItem) noexcept {
  const std::time_t currentTime = std::time(nullptr);