Chris@16: //
Chris@16: //=======================================================================
Chris@16: // Copyright 1997, 1998, 1999, 2000 University of Notre Dame.
Chris@16: // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //=======================================================================
Chris@16: //
Chris@16: //
Chris@16: // Revision History:
Chris@16: //   13 June 2001: Changed some names for clarity. (Jeremy Siek)
Chris@16: //   01 April 2001: Modified to use new <boost/limits.hpp> header. (JMaddock)
Chris@16: //
Chris@16: #ifndef BOOST_GRAPH_DETAIL_BUCKET_SORTER_HPP
Chris@16: #define BOOST_GRAPH_DETAIL_BUCKET_SORTER_HPP
Chris@16: 
Chris@16: #include <vector>
Chris@16: #include <cassert>
Chris@16: #include <boost/limits.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16:   template <class BucketType, class ValueType, class Bucket, 
Chris@16:             class ValueIndexMap>
Chris@16:   class bucket_sorter {
Chris@16:   public:
Chris@16:     typedef BucketType bucket_type;
Chris@16:     typedef ValueType value_type;
Chris@16:     typedef typename std::vector<value_type>::size_type size_type;
Chris@16:     
Chris@16:     bucket_sorter(size_type _length, bucket_type _max_bucket, 
Chris@16:                   const Bucket& _bucket = Bucket(), 
Chris@16:                   const ValueIndexMap& _id = ValueIndexMap()) 
Chris@16:       : head(_max_bucket, invalid_value()),
Chris@16:         next(_length, invalid_value()), 
Chris@16:         prev(_length, invalid_value()),
Chris@16:         id_to_value(_length),
Chris@16:         bucket(_bucket), id(_id) { }
Chris@16:     
Chris@16:     void remove(const value_type& x) {
Chris@16:       const size_type i = get(id, x);
Chris@16:       const size_type& next_node = next[i];
Chris@16:       const size_type& prev_node = prev[i];
Chris@16:     
Chris@16:       //check if i is the end of the bucket list 
Chris@16:       if ( next_node != invalid_value() )
Chris@16:         prev[next_node] = prev_node; 
Chris@16:       //check if i is the begin of the bucket list
Chris@16:       if ( prev_node != invalid_value() )
Chris@16:         next[prev_node] = next_node;
Chris@16:       else //need update head of current bucket list
Chris@16:         head[ bucket[x] ] = next_node;
Chris@16:     }
Chris@16: 
Chris@16:     void push(const value_type& x) {
Chris@16:       id_to_value[get(id, x)] = x;
Chris@16:       (*this)[bucket[x]].push(x);
Chris@16:     }
Chris@16:     
Chris@16:     void update(const value_type& x) {
Chris@16:       remove(x);
Chris@16:       (*this)[bucket[x]].push(x);
Chris@16:     }
Chris@16:     //  private: 
Chris@16:     //    with KCC, the nested stack class is having access problems
Chris@16:     //    despite the friend decl.
Chris@16:     static size_type invalid_value() {
Chris@16:       return (std::numeric_limits<size_type>::max)();
Chris@16:     }
Chris@16:     
Chris@16:     typedef typename std::vector<size_type>::iterator Iter;
Chris@16:     typedef typename std::vector<value_type>::iterator IndexValueMap;
Chris@16:     
Chris@16:   public:
Chris@16:     friend class stack;
Chris@16: 
Chris@16:     class stack {
Chris@16:     public:
Chris@16:       stack(bucket_type _bucket_id, Iter h, Iter n, Iter p, IndexValueMap v,
Chris@16:             const ValueIndexMap& _id)
Chris@16:       : bucket_id(_bucket_id), head(h), next(n), prev(p), value(v), id(_id) {}
Chris@16: 
Chris@16:       // Avoid using default arg for ValueIndexMap so that the default
Chris@16:       // constructor of the ValueIndexMap is not required if not used.
Chris@16:       stack(bucket_type _bucket_id, Iter h, Iter n, Iter p, IndexValueMap v)
Chris@16:         : bucket_id(_bucket_id), head(h), next(n), prev(p), value(v) {}
Chris@16:       
Chris@16:       void push(const value_type& x) {
Chris@16:         const size_type new_head = get(id, x);
Chris@16:         const size_type current = head[bucket_id];
Chris@16:         if ( current != invalid_value() )
Chris@16:           prev[current] = new_head;
Chris@16:         prev[new_head] = invalid_value();
Chris@16:         next[new_head] = current;
Chris@16:         head[bucket_id] = new_head;
Chris@16:       }
Chris@16:       void pop() {
Chris@16:         size_type current = head[bucket_id];
Chris@16:         size_type next_node = next[current];
Chris@16:         head[bucket_id] = next_node;
Chris@16:         if ( next_node != invalid_value() )
Chris@16:           prev[next_node] = invalid_value();
Chris@16:       }
Chris@16:       value_type& top() { return value[ head[bucket_id] ]; }
Chris@16:       const value_type& top() const { return value[ head[bucket_id] ]; }
Chris@16:       bool empty() const { return head[bucket_id] == invalid_value(); }
Chris@16:     private:
Chris@16:       bucket_type bucket_id;
Chris@16:       Iter head;
Chris@16:       Iter next;
Chris@16:       Iter prev;
Chris@16:       IndexValueMap value;
Chris@16:       ValueIndexMap id;
Chris@16:     };
Chris@16:     
Chris@16:     stack operator[](const bucket_type& i) {
Chris@16:       assert(i < head.size());
Chris@16:       return stack(i, head.begin(), next.begin(), prev.begin(),
Chris@16:                    id_to_value.begin(), id);
Chris@16:     }
Chris@16:   protected:
Chris@16:     std::vector<size_type>   head;
Chris@16:     std::vector<size_type>   next;
Chris@16:     std::vector<size_type>   prev;
Chris@16:     std::vector<value_type>  id_to_value;
Chris@16:     Bucket bucket;
Chris@16:     ValueIndexMap id;
Chris@16:   };
Chris@16:   
Chris@16: }
Chris@16: 
Chris@16: #endif