libosgearth-dev 2.5.0+dfsg-8build1 / usr / include / osgEarth / Containers

/* -*-c++-*- */
/* osgEarth - Dynamic map generation toolkit for OpenSceneGraph
* Copyright 2008-2013 Pelican Mapping
* http://osgearth.org
*
* osgEarth is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program.  If not, see <http://www.gnu.org/licenses/>
*/
#ifndef OSGEARTH_CONTAINERS_H
#define OSGEARTH_CONTAINERS_H 1

#include <osgEarth/Common>
#include <osgEarth/ThreadingUtils>
#include <list>
#include <vector>

namespace osgEarth
{
    /**
     * A std::map-like container that is faster than std::map for small amounts
     * of data accessed by a single user
     */
    template<typename KEY, typename DATA>
    struct fast_map
    {
        typedef std::pair<KEY,DATA> entry_t;
        typedef std::list<entry_t>  list_t;

        typedef typename list_t::iterator       iterator;
        typedef typename list_t::const_iterator const_iterator;

        list_t _data;
        KEY    _lastKey;

        DATA& operator[] (const KEY& key) {
            for( iterator i = _data.begin(); i != _data.end(); ++i ) {
                if ( i->first == key ) {
                    if ( _lastKey == key && i != _data.begin() ) {
                        _data.insert(begin(), *i);
                        _data.erase(i);
                        return _data.front().second;
                    }
                    else {
                        _lastKey = key;
                        return i->second;
                    }
                }
            }
            _data.push_back(entry_t(key,DATA()));
            return _data.back().second;
        }

        iterator find( const KEY& key ) {
            for( iterator i = _data.begin(); i != _data.end(); ++i ) {
                if ( i->first == key ) {
                    return i;
                }
            }
            return end();
        }

        const_iterator find( const KEY& key ) const {
            for( const_iterator i = _data.begin(); i != _data.end(); ++i ) {
                if ( i->first == key ) {
                    return i;
                }
            }
            return end();
        }

        const_iterator begin() const { return _data.begin(); }
        const_iterator end() const { return _data.end(); }
        iterator begin() { return _data.begin(); }
        iterator end() { return _data.end(); }

        bool empty() const { return _data.empty(); }
    };

    //------------------------------------------------------------------------

    struct CacheStats
    {
    public:
        CacheStats( unsigned entries, unsigned maxEntries, unsigned queries, float hitRatio )
            : _entries(entries), _maxEntries(maxEntries), _queries(queries), _hitRatio(hitRatio) { }

        /** dtor */
        virtual ~CacheStats() { }

        unsigned _entries;
        unsigned _maxEntries;
        unsigned _queries;
        float    _hitRatio;
    };

    //------------------------------------------------------------------------

    /**
     * Least-recently-used cache class.
     * K = key type, T = value type
     *
     * usage:
     *    LRUCache<K,T> cache;
     *    cache.put( key, value );
     *    LRUCache.Record rec = cache.get( key );
     *    if ( rec.valid() )
     *        const T& value = rec.value();
     */
    template<typename K, typename T, typename COMPARE=std::less<K> >
    class LRUCache
    {
    public:
        struct Record {
            Record() : _valid(false) { }
            Record(const T& value) : _value(value), _valid(true) { }
            const bool valid() const { return _valid; }
            const T& value() const { return _value; }
        private:
            bool _valid;
            T    _value;
            friend class LRUCache;
        };

    protected:
        typedef typename std::list<K>::iterator      lru_iter;
        typedef typename std::list<K>                lru_type;
        typedef typename std::pair<T, lru_iter>      map_value_type;
        typedef typename std::map<K, map_value_type> map_type;
        typedef typename map_type::iterator          map_iter;

        map_type _map;
        lru_type _lru;
        unsigned _max;
        unsigned _buf;
        unsigned _queries;
        unsigned _hits;
        bool     _threadsafe;
        mutable Threading::Mutex _mutex;

    public:
        LRUCache( unsigned max =100 ) : _max(max), _threadsafe(false) {
            _buf = _max/10;
            _queries = 0;
            _hits = 0;
        }
        LRUCache( bool threadsafe, unsigned max =100 ) : _max(max), _threadsafe(threadsafe) {
            _buf = _max/10;
            _queries = 0;
            _hits = 0;
        }

        /** dtor */
        virtual ~LRUCache() { }

        void insert( const K& key, const T& value ) {
            if ( _threadsafe ) {
                Threading::ScopedMutexLock lock(_mutex);
                insert_impl( key, value );
            }
            else {
                insert_impl( key, value );
            }
        }

        bool get( const K& key, Record& out ) {
            if ( _threadsafe ) {
                Threading::ScopedMutexLock lock(_mutex);
                get_impl( key, out );
            }
            else {
                get_impl( key, out );
            }
            return out.valid();
        }

        bool has( const K& key ) {
            if ( _threadsafe ) {
                Threading::ScopedMutexLock lock(_mutex);
                return has_impl( key );
            }
            else {
                return has_impl( key );
            }
        }

        void erase( const K& key ) {
            if ( _threadsafe ) {
                Threading::ScopedMutexLock lock(_mutex);
                erase_impl( key );
            }
            else {
                erase_impl( key );
            }
        }

        void clear() {
            if ( _threadsafe ) {
                Threading::ScopedMutexLock lock(_mutex);
                clear_impl();
            }
            else {
                clear_impl();
            }
        }

        void setMaxSize( unsigned max ) {
            if ( _threadsafe ) {
                Threading::ScopedMutexLock lock(_mutex);
                setMaxSize_impl( max );
            }
            else {
                setMaxSize_impl( max );
            }
        }

        unsigned getMaxSize() const {
            return _max;
        }

        CacheStats getStats() const {
            return CacheStats(
                _lru.size(), _max, _queries, _queries > 0 ? (float)_hits/(float)_queries : 0.0f );
        }

    private:

        void insert_impl( const K& key, const T& value ) {
            map_iter mi = _map.find( key );
            if ( mi != _map.end() ) {
                _lru.erase( mi->second.second );
                mi->second.first = value;
                _lru.push_back( key );
                mi->second.second = _lru.end();
                mi->second.second--;
            }
            else {
                _lru.push_back( key );
                lru_iter last = _lru.end(); last--;
                _map[key] = std::make_pair(value, last);
            }

            if ( _lru.size() > _max ) {
                for( unsigned i=0; i < _buf; ++i ) {
                    const K& key = _lru.front();
                    _map.erase( key );
                    _lru.pop_front();
                }
            }
        }

        void get_impl( const K& key, Record& result ) {
            _queries++;
            map_iter mi = _map.find( key );
            if ( mi != _map.end() ) {
                _lru.erase( mi->second.second );
                _lru.push_back( key );
                lru_iter new_iter = _lru.end(); new_iter--;
                mi->second.second = new_iter;
                _hits++;
                result._value = mi->second.first;
                result._valid = true;
                //return Record( &(mi->second.first) );
            }
            //else {
            //    return Record( 0L );
            //}
        }

        bool has_impl( const K& key ) {
            return _map.find( key ) != _map.end();
        }

        void erase_impl( const K& key ) {
            map_iter mi = _map.find( key );
            if ( mi != _map.end() ) {
                _lru.erase( mi->second.second );
                _map.erase( mi );
            }
        }

        void clear_impl() {
            _lru.clear();
            _map.clear();
            _queries = 0;
            _hits = 0;
        }

        void setMaxSize_impl( unsigned max ) {
            _max = max;
            _buf = max/10;
            while( _lru.size() > _max ) {
                const K& key = _lru.front();
                _map.erase( key );
                _lru.pop_front();
            }
        }

    };

    //--------------------------------------------------------------------

    /**
     * Same of osg::MixinVector, but with a superclass template parameter.
     */
    template<class ValueT, class SuperClass>
    class MixinVector : public SuperClass
    {
        typedef typename std::vector<ValueT> vector_type;
    public:
        typedef typename vector_type::allocator_type allocator_type;
        typedef typename vector_type::value_type value_type;
        typedef typename vector_type::const_pointer const_pointer;
        typedef typename vector_type::pointer pointer;
        typedef typename vector_type::const_reference const_reference;
        typedef typename vector_type::reference reference;
        typedef typename vector_type::const_iterator const_iterator;
        typedef typename vector_type::iterator iterator;
        typedef typename vector_type::const_reverse_iterator const_reverse_iterator;
        typedef typename vector_type::reverse_iterator reverse_iterator;
        typedef typename vector_type::size_type size_type;
        typedef typename vector_type::difference_type difference_type;

        explicit MixinVector() : _impl()
        {
        }

        explicit MixinVector(size_type initial_size, const value_type& fill_value = value_type())
        : _impl(initial_size, fill_value)
        {
        }

        template<class InputIterator>
        MixinVector(InputIterator first, InputIterator last)
        : _impl(first, last)
        {
        }

        MixinVector(const vector_type& other)
        : _impl(other)
        {
        }

        MixinVector(const MixinVector& other)
        : _impl(other._impl)
        {
        }

        MixinVector& operator=(const vector_type& other)
        {
            _impl = other;
            return *this;
        }

        MixinVector& operator=(const MixinVector& other)
        {
            _impl = other._impl;
            return *this;
        }

        virtual ~MixinVector() {}

        void clear() { _impl.clear(); }
        void resize(size_type new_size, const value_type& fill_value = value_type()) { _impl.resize(new_size, fill_value); }
        void reserve(size_type new_capacity) { _impl.reserve(new_capacity); }
        
        void swap(vector_type& other) { _impl.swap(other); }
        void swap(MixinVector& other) { _impl.swap(other._impl); }

        bool empty() const { return _impl.empty(); }
        size_type size() const { return _impl.size(); }
        size_type capacity() const { return _impl.capacity(); }
        size_type max_size() const { return _impl.max_size(); }
        allocator_type get_allocator() const { return _impl.get_allocator(); }

        const_iterator begin() const { return _impl.begin(); }
        iterator begin() { return _impl.begin(); }
        const_iterator end() const { return _impl.end(); }
        iterator end() { return _impl.end(); }

        const_reverse_iterator rbegin() const { return _impl.rbegin(); }
        reverse_iterator rbegin() { return _impl.rbegin(); }
        const_reverse_iterator rend() const { return _impl.rend(); }
        reverse_iterator rend() { return _impl.rend(); }

        const_reference operator[](size_type index) const { return _impl[index]; }
        reference operator[](size_type index) { return _impl[index]; }

        const_reference at(size_type index) const { return _impl.at(index); }
        reference at(size_type index) { return _impl.at(index); }

        void assign(size_type count, const value_type& value) { _impl.assign(count, value); }
        template<class Iter>
        void assign(Iter first, Iter last) { _impl.assign(first, last); }

        void push_back(const value_type& value) { _impl.push_back(value); }
        void pop_back() { _impl.pop_back(); }

        iterator erase(iterator where) { return _impl.erase(where); }
        iterator erase(iterator first, iterator last) { return _impl.erase(first, last); }

        iterator insert(iterator where, const value_type& value) { return _impl.insert(where, value); }

        template<class InputIterator>
        void insert(iterator where, InputIterator first, InputIterator last)
        {
            _impl.insert(where, first, last);
        }

        void insert(iterator where, size_type count, const value_type& value)
        {
            _impl.insert(where, count, value);
        }

        const_reference back() const { return _impl.back(); }
        reference back() { return _impl.back(); }
        const_reference front() const { return _impl.front(); }
        reference front() { return _impl.front(); }

        vector_type& asVector() { return _impl; }
        const vector_type& asVector() const { return _impl; }

        friend inline bool operator==(const MixinVector<ValueT,SuperClass>& left, const MixinVector<ValueT,SuperClass>& right) { return left._impl == right._impl; }
        friend inline bool operator==(const MixinVector<ValueT,SuperClass>& left, const std::vector<ValueT>& right) { return left._impl == right; }
        friend inline bool operator==(const std::vector<ValueT>& left, const MixinVector<ValueT,SuperClass>& right) { return left == right._impl; }

        friend inline bool operator!=(const MixinVector<ValueT,SuperClass>& left, const MixinVector<ValueT,SuperClass>& right) { return left._impl != right._impl; }
        friend inline bool operator!=(const MixinVector<ValueT,SuperClass>& left, const std::vector<ValueT>& right) { return left._impl != right; }
        friend inline bool operator!=(const std::vector<ValueT>& left, const MixinVector<ValueT,SuperClass>& right) { return left != right._impl; }

        friend inline bool operator<(const MixinVector<ValueT,SuperClass>& left, const MixinVector<ValueT,SuperClass>& right) { return left._impl < right._impl; }
        friend inline bool operator<(const MixinVector<ValueT,SuperClass>& left, const std::vector<ValueT>& right) { return left._impl < right; }
        friend inline bool operator<(const std::vector<ValueT>& left, const MixinVector<ValueT,SuperClass>& right) { return left < right._impl; }

        friend inline bool operator>(const MixinVector<ValueT,SuperClass>& left, const MixinVector<ValueT,SuperClass>& right) { return left._impl > right._impl; }
        friend inline bool operator>(const MixinVector<ValueT,SuperClass>& left, const std::vector<ValueT>& right) { return left._impl > right; }
        friend inline bool operator>(const std::vector<ValueT>& left, const MixinVector<ValueT,SuperClass>& right) { return left > right._impl; }

        friend inline bool operator<=(const MixinVector<ValueT,SuperClass>& left, const MixinVector<ValueT,SuperClass>& right) { return left._impl <= right._impl; }
        friend inline bool operator<=(const MixinVector<ValueT,SuperClass>& left, const std::vector<ValueT>& right) { return left._impl <= right; }
        friend inline bool operator<=(const std::vector<ValueT>& left, const MixinVector<ValueT,SuperClass>& right) { return left <= right._impl; }

        friend inline bool operator>=(const MixinVector<ValueT,SuperClass>& left, const MixinVector<ValueT,SuperClass>& right) { return left._impl >= right._impl; }
        friend inline bool operator>=(const MixinVector<ValueT,SuperClass>& left, const std::vector<ValueT>& right) { return left._impl >= right; }
        friend inline bool operator>=(const std::vector<ValueT>& left, const MixinVector<ValueT,SuperClass>& right) { return left >= right._impl; }

    private:
        vector_type _impl;
    };

}

#endif // OSGEARTH_CONTAINERS_H