Method Prev

src/leveldb/table/merger.cc:81–108

  }

  void Prev() override {
    assert(Valid());

    // Ensure that all children are positioned before key().
    // If we are moving in the reverse direction, it is already
    // true for all of the non-current_ children since current_ is
    // the largest child and key() == current_->key().  Otherwise,
    // we explicitly position the non-current_ children.
    if (direction_ != kReverse) {
      for (int i = 0; i < n_; i++) {
        IteratorWrapper* child = &children_[i];
        if (child != current_) {
          child->Seek(key());
          if (child->Valid()) {
            // Child is at first entry >= key().  Step back one to be < key()
            child->Prev();
          } else {
            // Child has no entries >= key().  Position at last entry.
            child->SeekToLast();
          }
        }
      }
      direction_ = kReverse;
    }

    current_->Prev();
    FindLargest();
  }

  Slice key() const override {
    assert(Valid());