utils/joiner/btree_container.h

// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef UTIL_BTREE_BTREE_CONTAINER_H__
#define UTIL_BTREE_BTREE_CONTAINER_H__

#include <iosfwd>
#include <utility>

#include "btree.h"

namespace btree
{

// A common base class for btree_set, btree_map, btree_multiset and
// btree_multimap.
template <typename Tree>
class btree_container
{
    typedef btree_container<Tree> self_type;

public:
    typedef typename Tree::params_type params_type;
    typedef typename Tree::key_type key_type;
    typedef typename Tree::value_type value_type;
    typedef typename Tree::key_compare key_compare;
    typedef typename Tree::allocator_type allocator_type;
    typedef typename Tree::pointer pointer;
    typedef typename Tree::const_pointer const_pointer;
    typedef typename Tree::reference reference;
    typedef typename Tree::const_reference const_reference;
    typedef typename Tree::size_type size_type;
    typedef typename Tree::difference_type difference_type;
    typedef typename Tree::iterator iterator;
    typedef typename Tree::const_iterator const_iterator;
    typedef typename Tree::reverse_iterator reverse_iterator;
    typedef typename Tree::const_reverse_iterator const_reverse_iterator;

public:
    // Default constructor.
    btree_container(const key_compare& comp, const allocator_type& alloc)
        : tree_(comp, alloc)
    {
    }

    // Copy constructor.
    btree_container(const self_type& x)
        : tree_(x.tree_)
    {
    }

    // Iterator routines.
    iterator begin()
    {
        return tree_.begin();
    }
    const_iterator begin() const
    {
        return tree_.begin();
    }
    iterator end()
    {
        return tree_.end();
    }
    const_iterator end() const
    {
        return tree_.end();
    }
    reverse_iterator rbegin()
    {
        return tree_.rbegin();
    }
    const_reverse_iterator rbegin() const
    {
        return tree_.rbegin();
    }
    reverse_iterator rend()
    {
        return tree_.rend();
    }
    const_reverse_iterator rend() const
    {
        return tree_.rend();
    }

    // Lookup routines.
    iterator lower_bound(const key_type& key)
    {
        return tree_.lower_bound(key);
    }
    const_iterator lower_bound(const key_type& key) const
    {
        return tree_.lower_bound(key);
    }
    iterator upper_bound(const key_type& key)
    {
        return tree_.upper_bound(key);
    }
    const_iterator upper_bound(const key_type& key) const
    {
        return tree_.upper_bound(key);
    }
    std::pair<iterator, iterator> equal_range(const key_type& key)
    {
        return tree_.equal_range(key);
    }
    std::pair<const_iterator, const_iterator> equal_range(const key_type& key) const
    {
        return tree_.equal_range(key);
    }

    // Utility routines.
    void clear()
    {
        tree_.clear();
    }
    void swap(self_type& x)
    {
        tree_.swap(x.tree_);
    }
    void dump(std::ostream& os) const
    {
        tree_.dump(os);
    }
    void verify() const
    {
        tree_.verify();
    }

    // Size routines.
    size_type size() const
    {
        return tree_.size();
    }
    size_type max_size() const
    {
        return tree_.max_size();
    }
    bool empty() const
    {
        return tree_.empty();
    }
    size_type height() const
    {
        return tree_.height();
    }
    size_type internal_nodes() const
    {
        return tree_.internal_nodes();
    }
    size_type leaf_nodes() const
    {
        return tree_.leaf_nodes();
    }
    size_type nodes() const
    {
        return tree_.nodes();
    }
    size_type bytes_used() const
    {
        return tree_.bytes_used();
    }
    static double average_bytes_per_value()
    {
        return Tree::average_bytes_per_value();
    }
    double fullness() const
    {
        return tree_.fullness();
    }
    double overhead() const
    {
        return tree_.overhead();
    }

    bool operator==(const self_type& x) const
    {
        if (size() != x.size())
        {
            return false;
        }

        for (const_iterator i = begin(), xi = x.begin(); i != end(); ++i, ++xi)
        {
            if (*i != *xi)
            {
                return false;
            }
        }

        return true;
    }

    bool operator!=(const self_type& other) const
    {
        return !operator==(other);
    }


protected:
    Tree tree_;
};

template <typename T>
inline std::ostream& operator<<(std::ostream& os, const btree_container<T>& b)
{
    b.dump(os);
    return os;
}

// A common base class for btree_set and safe_btree_set.
template <typename Tree>
class btree_unique_container : public btree_container<Tree>
{
    typedef btree_unique_container<Tree> self_type;
    typedef btree_container<Tree> super_type;

public:
    typedef typename Tree::key_type key_type;
    typedef typename Tree::value_type value_type;
    typedef typename Tree::size_type size_type;
    typedef typename Tree::key_compare key_compare;
    typedef typename Tree::allocator_type allocator_type;
    typedef typename Tree::iterator iterator;
    typedef typename Tree::const_iterator const_iterator;

public:
    // Default constructor.
    btree_unique_container(const key_compare& comp = key_compare(),
                           const allocator_type& alloc = allocator_type())
        : super_type(comp, alloc)
    {
    }

    // Copy constructor.
    btree_unique_container(const self_type& x)
        : super_type(x)
    {
    }

    // Range constructor.
    template <class InputIterator>
    btree_unique_container(InputIterator b, InputIterator e,
                           const key_compare& comp = key_compare(),
                           const allocator_type& alloc = allocator_type())
        : super_type(comp, alloc)
    {
        insert(b, e);
    }

    // Lookup routines.
    iterator find(const key_type& key)
    {
        return this->tree_.find_unique(key);
    }
    const_iterator find(const key_type& key) const
    {
        return this->tree_.find_unique(key);
    }
    size_type count(const key_type& key) const
    {
        return this->tree_.count_unique(key);
    }

    // Insertion routines.
    std::pair<iterator, bool> insert(const value_type& x)
    {
        return this->tree_.insert_unique(x);
    }
    iterator insert(iterator position, const value_type& x)
    {
        return this->tree_.insert_unique(position, x);
    }
    template <typename InputIterator>
    void insert(InputIterator b, InputIterator e)
    {
        this->tree_.insert_unique(b, e);
    }

    // Deletion routines.
    int erase(const key_type& key)
    {
        return this->tree_.erase_unique(key);
    }
    // Erase the specified iterator from the btree. The iterator must be valid
    // (i.e. not equal to end()).  Return an iterator pointing to the node after
    // the one that was erased (or end() if none exists).
    iterator erase(const iterator& iter)
    {
        return this->tree_.erase(iter);
    }
    void erase(const iterator& first, const iterator& last)
    {
        this->tree_.erase(first, last);
    }
};

// A common base class for btree_map and safe_btree_map.
template <typename Tree>
class btree_map_container : public btree_unique_container<Tree>
{
    typedef btree_map_container<Tree> self_type;
    typedef btree_unique_container<Tree> super_type;

public:
    typedef typename Tree::key_type key_type;
    typedef typename Tree::data_type data_type;
    typedef typename Tree::value_type value_type;
    typedef typename Tree::mapped_type mapped_type;
    typedef typename Tree::key_compare key_compare;
    typedef typename Tree::allocator_type allocator_type;

private:
    // A pointer-like object which only generates its value when
    // dereferenced. Used by operator[] to avoid constructing an empty data_type
    // if the key already exists in the map.
    struct generate_value
    {
        generate_value(const key_type& k)
            : key(k)
        {
        }
        value_type operator*() const
        {
            return std::make_pair(key, data_type());
        }
        const key_type& key;
    };

public:
    // Default constructor.
    btree_map_container(const key_compare& comp = key_compare(),
                        const allocator_type& alloc = allocator_type())
        : super_type(comp, alloc)
    {
    }

    // Copy constructor.
    btree_map_container(const self_type& x)
        : super_type(x)
    {
    }

    // Range constructor.
    template <class InputIterator>
    btree_map_container(InputIterator b, InputIterator e,
                        const key_compare& comp = key_compare(),
                        const allocator_type& alloc = allocator_type())
        : super_type(b, e, comp, alloc)
    {
    }

    // Insertion routines.
    data_type& operator[](const key_type& key)
    {
        return this->tree_.insert_unique(key, generate_value(key)).first->second;
    }
};

// A common base class for btree_multiset and btree_multimap.
template <typename Tree>
class btree_multi_container : public btree_container<Tree>
{
    typedef btree_multi_container<Tree> self_type;
    typedef btree_container<Tree> super_type;

public:
    typedef typename Tree::key_type key_type;
    typedef typename Tree::value_type value_type;
    typedef typename Tree::size_type size_type;
    typedef typename Tree::key_compare key_compare;
    typedef typename Tree::allocator_type allocator_type;
    typedef typename Tree::iterator iterator;
    typedef typename Tree::const_iterator const_iterator;

public:
    // Default constructor.
    btree_multi_container(const key_compare& comp = key_compare(),
                          const allocator_type& alloc = allocator_type())
        : super_type(comp, alloc)
    {
    }

    // Copy constructor.
    btree_multi_container(const self_type& x)
        : super_type(x)
    {
    }

    // Range constructor.
    template <class InputIterator>
    btree_multi_container(InputIterator b, InputIterator e,
                          const key_compare& comp = key_compare(),
                          const allocator_type& alloc = allocator_type())
        : super_type(comp, alloc)
    {
        insert(b, e);
    }

    // Lookup routines.
    iterator find(const key_type& key)
    {
        return this->tree_.find_multi(key);
    }
    const_iterator find(const key_type& key) const
    {
        return this->tree_.find_multi(key);
    }
    size_type count(const key_type& key) const
    {
        return this->tree_.count_multi(key);
    }

    // Insertion routines.
    iterator insert(const value_type& x)
    {
        return this->tree_.insert_multi(x);
    }
    iterator insert(iterator position, const value_type& x)
    {
        return this->tree_.insert_multi(position, x);
    }
    template <typename InputIterator>
    void insert(InputIterator b, InputIterator e)
    {
        this->tree_.insert_multi(b, e);
    }

    // Deletion routines.
    int erase(const key_type& key)
    {
        return this->tree_.erase_multi(key);
    }
    // Erase the specified iterator from the btree. The iterator must be valid
    // (i.e. not equal to end()).  Return an iterator pointing to the node after
    // the one that was erased (or end() if none exists).
    iterator erase(const iterator& iter)
    {
        return this->tree_.erase(iter);
    }
    void erase(const iterator& first, const iterator& last)
    {
        this->tree_.erase(first, last);
    }
};

} // namespace btree

#endif  // UTIL_BTREE_BTREE_CONTAINER_H__