Status DBImpl::WriteLevel0Table(MemTable* mem, VersionEdit* edit,
                                Version* base)

BuildTable(const std::string& dbname, Env* env, const Options& options,
                  TableCache* table_cache, Iterator* iter, FileMetaData* meta)

TableBuilder* builder = new TableBuilder(options, file);
    meta->smallest.DecodeFrom(iter->key());
    for (; iter->Valid(); iter->Next()) {
      Slice key = iter->key();
      meta->largest.DecodeFrom(key);
      builder->Add(key, iter->value());
    }

bool DecodeFrom(const Slice& s) {
    rep_.assign(s.data(), s.size());
    return !rep_.empty();
  }