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moslab-code/src/l4/pkg/l4re-core/cxx/lib/tl/include/avl_map
2025-09-12 15:55:45 +02:00

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// vi:set ft=cpp: -*- Mode: C++ -*-
/**
* \file
* \brief AVL map
*/
/*
* (c) 2008-2009 Alexander Warg <warg@os.inf.tu-dresden.de>
* economic rights: Technische Universität Dresden (Germany)
*
* License: see LICENSE.spdx (in this directory or the directories above)
*/
#pragma once
#include <l4/cxx/std_alloc>
#include <l4/cxx/std_ops>
#include <l4/cxx/pair>
#include <l4/cxx/avl_set>
namespace cxx {
namespace Bits {
/// Key-getter for Avl_map
template<typename KEY_TYPE>
struct Avl_map_get_key
{
typedef KEY_TYPE Key_type;
template<typename NODE>
static Key_type const &key_of(NODE const *n)
{ return n->item.first; }
};
}
/**
* AVL tree based associative container.
*
* \tparam KEY_TYPE Type of the key values.
* \tparam DATA_TYPE Type of the data values.
* \tparam COMPARE Type comparison functor for the key values.
* \tparam ALLOC Type of the allocator used for the nodes.
*/
template< typename KEY_TYPE, typename DATA_TYPE,
template<typename A> class COMPARE = Lt_functor,
template<typename B> class ALLOC = New_allocator >
class Avl_map :
public Bits::Base_avl_set<Pair<KEY_TYPE, DATA_TYPE>,
COMPARE<KEY_TYPE>, ALLOC,
Bits::Avl_map_get_key<KEY_TYPE> >
{
private:
typedef Pair<KEY_TYPE, DATA_TYPE> Local_item_type;
typedef Bits::Base_avl_set<Local_item_type, COMPARE<KEY_TYPE>, ALLOC,
Bits::Avl_map_get_key<KEY_TYPE> > Base_type;
public:
/// Type of the comparison functor.
typedef COMPARE<KEY_TYPE> Key_compare;
/// Type of the key values.
typedef KEY_TYPE Key_type;
/// Type of the data values.
typedef DATA_TYPE Data_type;
/// Return type for find.
typedef typename Base_type::Node Node;
/// Type of the allocator
typedef typename Base_type::Node_allocator Node_allocator;
typedef typename Base_type::Iterator Iterator;
typedef typename Base_type::Iterator iterator;
typedef typename Base_type::Const_iterator Const_iterator;
typedef typename Base_type::Const_iterator const_iterator;
typedef typename Base_type::Rev_iterator Rev_iterator;
typedef typename Base_type::Rev_iterator reverse_iterator;
typedef typename Base_type::Const_rev_iterator Const_rev_iterator;
typedef typename Base_type::Const_rev_iterator const_reverse_iterator;
/**
* \brief Create an empty AVL-tree based map.
* \param alloc The node allocator.
*/
Avl_map(Node_allocator const &alloc = Node_allocator())
: Base_type(alloc)
{}
/**
* Insert a <key, data> pair into the map.
*
* \param key The key value.
* \param data The data value to insert.
*
* \return A pair of iterator (`first`) and return value (`second`).
* `second` will be 0 if the element was inserted into the set
* and `-#E_exist` if the key was already in the set and the
* set was therefore not updated.
* In both cases, `first` contains an iterator that points to
* the element.
* `second` may also be `-#E_nomem` when memory for the new node
* could not be allocated. `first` is then invalid.
*/
cxx::Pair<Iterator, int> insert(Key_type const &key, Data_type const &data)
{ return Base_type::insert(Pair<Key_type, Data_type>(key, data)); }
template<typename... Args>
cxx::Pair<Iterator, int> emplace(Args &&...args)
{ return Base_type::emplace(cxx::forward<Args>(args)...); }
/**
* \brief Get the data for the given key.
* \param key The key value to use for lookup.
* \pre A <key, data> pair for the given key value must exist.
*/
Data_type const &operator [] (Key_type const &key) const
{ return this->find_node(key)->second; }
/**
* Get or insert data for the given key.
*
* \param key The key value to use for lookup.
*
* \return If the item already exists, a reference to the data item.
* Otherwise a new data item is default-constructed and inserted
* under the given key before a reference is returned.
*/
Data_type &operator [] (Key_type const &key)
{
Node n = this->find_node(key);
if (n)
return const_cast<Data_type&>(n->second);
else
return insert(key, Data_type()).first->second;
}
};
}