Status WriteDescriptor()

in db/repair.cc [348:406]
48 lines of code
9 McCabe index (conditional complexity)

  Status WriteDescriptor() {
    std::string tmp = TempFileName(dbname_, 1);
    WritableFile* file;
    Status status = env_->NewWritableFile(tmp, &file);
    if (!status.ok()) {
      return status;
    }

    SequenceNumber max_sequence = 0;
    for (size_t i = 0; i < tables_.size(); i++) {
      if (max_sequence < tables_[i].max_sequence) {
        max_sequence = tables_[i].max_sequence;
      }
    }

    edit_.SetComparatorName(icmp_.user_comparator()->Name());
    edit_.SetLogNumber(0);
    edit_.SetNextFile(next_file_number_);
    edit_.SetLastSequence(max_sequence);

    for (size_t i = 0; i < tables_.size(); i++) {
      // TODO(opt): separate out into multiple levels
      const TableInfo& t = tables_[i];
      edit_.AddFile(0, t.meta.number, t.meta.file_size, t.meta.smallest,
                    t.meta.largest);
    }

    // std::fprintf(stderr,
    //              "NewDescriptor:\n%s\n", edit_.DebugString().c_str());
    {
      log::Writer log(file);
      std::string record;
      edit_.EncodeTo(&record);
      status = log.AddRecord(record);
    }
    if (status.ok()) {
      status = file->Close();
    }
    delete file;
    file = nullptr;

    if (!status.ok()) {
      env_->RemoveFile(tmp);
    } else {
      // Discard older manifests
      for (size_t i = 0; i < manifests_.size(); i++) {
        ArchiveFile(dbname_ + "/" + manifests_[i]);
      }

      // Install new manifest
      status = env_->RenameFile(tmp, DescriptorFileName(dbname_, 1));
      if (status.ok()) {
        status = SetCurrentFile(env_, dbname_, 1);
      } else {
        env_->RemoveFile(tmp);
      }
    }
    return status;
  }