Method Prev

src/leveldb/db/db_iter.cc:209–234

}

void DBIter::Prev() {
  assert(valid_);

  if (direction_ == kForward) {  // Switch directions?
    // iter_ is pointing at the current entry.  Scan backwards until
    // the key changes so we can use the normal reverse scanning code.
    assert(iter_->Valid());  // Otherwise valid_ would have been false
    SaveKey(ExtractUserKey(iter_->key()), &saved_key_);
    while (true) {
      iter_->Prev();
      if (!iter_->Valid()) {
        valid_ = false;
        saved_key_.clear();
        ClearSavedValue();
        return;
      }
      if (user_comparator_->Compare(ExtractUserKey(iter_->key()), saved_key_) <
          0) {
        break;
      }
    }
    direction_ = kReverse;
  }

  FindPrevUserEntry();
}

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