void SaveTo()

in db/version_set.cc [672:715]

• 36 lines of code
• 8 McCabe index (conditional complexity)

  void SaveTo(Version* v) {
    BySmallestKey cmp;
    cmp.internal_comparator = &vset_->icmp_;
    for (int level = 0; level < config::kNumLevels; level++) {
      // Merge the set of added files with the set of pre-existing files.
      // Drop any deleted files.  Store the result in *v.
      const std::vector<FileMetaData*>& base_files = base_->files_[level];
      std::vector<FileMetaData*>::const_iterator base_iter = base_files.begin();
      std::vector<FileMetaData*>::const_iterator base_end = base_files.end();
      const FileSet* added_files = levels_[level].added_files;
      v->files_[level].reserve(base_files.size() + added_files->size());
      for (const auto& added_file : *added_files) {
        // Add all smaller files listed in base_
        for (std::vector<FileMetaData*>::const_iterator bpos =
                 std::upper_bound(base_iter, base_end, added_file, cmp);
             base_iter != bpos; ++base_iter) {
          MaybeAddFile(v, level, *base_iter);
        }

        MaybeAddFile(v, level, added_file);
      }

      // Add remaining base files
      for (; base_iter != base_end; ++base_iter) {
        MaybeAddFile(v, level, *base_iter);
      }

#ifndef NDEBUG
      // Make sure there is no overlap in levels > 0
      if (level > 0) {
        for (uint32_t i = 1; i < v->files_[level].size(); i++) {
          const InternalKey& prev_end = v->files_[level][i - 1]->largest;
          const InternalKey& this_begin = v->files_[level][i]->smallest;
          if (vset_->icmp_.Compare(prev_end, this_begin) >= 0) {
            std::fprintf(stderr, "overlapping ranges in same level %s vs. %s\n",
                         prev_end.DebugString().c_str(),
                         this_begin.DebugString().c_str());
            std::abort();
          }
        }
      }
#endif
    }
  }