Method FindPrevUserEntry

src/leveldb/db/db_iter.cc:236–276

}

void DBIter::FindPrevUserEntry() {
  assert(direction_ == kReverse);

  ValueType value_type = kTypeDeletion;
  if (iter_->Valid()) {
    do {
      ParsedInternalKey ikey;
      if (ParseKey(&ikey) && ikey.sequence <= sequence_) {
        if ((value_type != kTypeDeletion) &&
            user_comparator_->Compare(ikey.user_key, saved_key_) < 0) {
          // We encountered a non-deleted value in entries for previous keys,
          break;
        }
        value_type = ikey.type;
        if (value_type == kTypeDeletion) {
          saved_key_.clear();
          ClearSavedValue();
        } else {
          Slice raw_value = iter_->value();
          if (saved_value_.capacity() > raw_value.size() + 1048576) {
            std::string empty;
            swap(empty, saved_value_);
          }
          SaveKey(ExtractUserKey(iter_->key()), &saved_key_);
          saved_value_.assign(raw_value.data(), raw_value.size());
        }
      }
      iter_->Prev();
    } while (iter_->Valid());
  }

  if (value_type == kTypeDeletion) {
    // End
    valid_ = false;
    saved_key_.clear();
    ClearSavedValue();
    direction_ = kForward;
  } else {
    valid_ = true;
  }
}

void DBIter::Seek(const Slice& target) {
  direction_ = kForward;