Method clearPermanently

src/traffic_cache_tool/CacheTool.cc:882–910

}

void
Span::clearPermanently()
{
  if (OPEN_RW_FLAG) {
    alignas(512) static char zero[CacheStoreBlocks::SCALE]; // should be all zero, it's static.
    std::cout << "Clearing " << _path.string() << " permanently on disk ";
    ssize_t n = pwrite(_fd, zero, sizeof(zero), ts::CacheSpan::OFFSET);
    if (n == sizeof(zero)) {
      std::cout << "done";
    } else {
      const char *text = strerror(errno);
      std::cout << "failed";
      if (n >= 0) {
        std::cout << " - " << n << " of " << sizeof(zero) << " bytes written";
      }
      std::cout << " - " << text;
    }

    std::cout << std::endl;
    // clear the stripes as well
    for (auto *strp : _stripes) {
      strp->loadMeta();
      std::cout << "Clearing stripe @" << strp->_start << " of length: " << strp->_len << std::endl;
      strp->clear();
    }
  } else {
    std::cout << "Clearing " << _path.string() << " not performed, write not enabled" << std::endl;
  }
}

// explicit pair for random table in build_vol_hash_table
struct rtable_pair {