Status Version::Get()

in db/version_set.cc [324:400]
62 lines of code
9 McCabe index (conditional complexity)

Status Version::Get(const ReadOptions& options, const LookupKey& k,
                    std::string* value, GetStats* stats) {
  stats->seek_file = nullptr;
  stats->seek_file_level = -1;

  struct State {
    Saver saver;
    GetStats* stats;
    const ReadOptions* options;
    Slice ikey;
    FileMetaData* last_file_read;
    int last_file_read_level;

    VersionSet* vset;
    Status s;
    bool found;

    static bool Match(void* arg, int level, FileMetaData* f) {
      State* state = reinterpret_cast<State*>(arg);

      if (state->stats->seek_file == nullptr &&
          state->last_file_read != nullptr) {
        // We have had more than one seek for this read.  Charge the 1st file.
        state->stats->seek_file = state->last_file_read;
        state->stats->seek_file_level = state->last_file_read_level;
      }

      state->last_file_read = f;
      state->last_file_read_level = level;

      state->s = state->vset->table_cache_->Get(*state->options, f->number,
                                                f->file_size, state->ikey,
                                                &state->saver, SaveValue);
      if (!state->s.ok()) {
        state->found = true;
        return false;
      }
      switch (state->saver.state) {
        case kNotFound:
          return true;  // Keep searching in other files
        case kFound:
          state->found = true;
          return false;
        case kDeleted:
          return false;
        case kCorrupt:
          state->s =
              Status::Corruption("corrupted key for ", state->saver.user_key);
          state->found = true;
          return false;
      }

      // Not reached. Added to avoid false compilation warnings of
      // "control reaches end of non-void function".
      return false;
    }
  };

  State state;
  state.found = false;
  state.stats = stats;
  state.last_file_read = nullptr;
  state.last_file_read_level = -1;

  state.options = &options;
  state.ikey = k.internal_key();
  state.vset = vset_;

  state.saver.state = kNotFound;
  state.saver.ucmp = vset_->icmp_.user_comparator();
  state.saver.user_key = k.user_key();
  state.saver.value = value;

  ForEachOverlapping(state.saver.user_key, state.ikey, &state, &State::Match);

  return state.found ? state.s : Status::NotFound(Slice());
}