Method lookup

pj_scene2D/core/src/entry_thumbnail_cache.cpp:40–53

}

std::optional<DecodedFrame> EntryThumbnailCache::lookup(Timestamp ts_ns) const {
  std::lock_guard<std::mutex> lock(mutex_);
  if (tiles_.empty()) {
    return std::nullopt;
  }
  // Nearest at-or-before: first tile with ts > ts_ns, then step back one.
  auto it =
      std::upper_bound(tiles_.begin(), tiles_.end(), ts_ns, [](Timestamp t, const Tile& tile) { return t < tile.ts; });
  if (it == tiles_.begin()) {
    return std::nullopt;
  }
  --it;
  return decodeThumbnailJpeg(it->jpeg.data(), it->jpeg.size(), it->width, it->height);
}

void EntryThumbnailCache::prune(Timestamp before_ns) {
  std::lock_guard<std::mutex> lock(mutex_);