110 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			110 lines
		
	
	
		
			3.5 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
| // Copyright (C) 2005-2006 The Trustees of Indiana University.
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| 
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| // Distributed under the Boost Software License, Version 1.0.
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| // (See accompanying file LICENSE_1_0.txt or copy at
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| // http://www.boost.org/LICENSE_1_0.txt)
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| 
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| //  Authors: Jeremiah Willcock
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| //           Douglas Gregor
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| //           Andrew Lumsdaine
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| 
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| // Two bit per color property map
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| 
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| #ifndef BOOST_TWO_BIT_COLOR_MAP_HPP
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| #define BOOST_TWO_BIT_COLOR_MAP_HPP
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| 
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| #include <boost/property_map/property_map.hpp>
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| #include <boost/graph/properties.hpp>
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| #include <boost/shared_array.hpp>
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| #include <boost/config.hpp>
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| #include <boost/assert.hpp>
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| #include <algorithm>
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| #include <limits>
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| 
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| namespace boost {
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| 
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| enum two_bit_color_type { 
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|   two_bit_white = 0, 
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|   two_bit_gray  = 1, 
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|   two_bit_green = 2, 
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|   two_bit_black = 3 
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| };
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| 
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| template <>
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| struct color_traits<two_bit_color_type>
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| {
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|   static two_bit_color_type white() { return two_bit_white; }
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|   static two_bit_color_type gray()  { return two_bit_gray; }
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|   static two_bit_color_type green() { return two_bit_green; }
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|   static two_bit_color_type black() { return two_bit_black; }
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| };
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| 
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| 
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| template<typename IndexMap = identity_property_map>
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| struct two_bit_color_map 
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| {
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|   std::size_t n;
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|   IndexMap index;
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|   shared_array<unsigned char> data;
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| 
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|   BOOST_STATIC_CONSTANT(int, bits_per_char = std::numeric_limits<unsigned char>::digits);
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|   BOOST_STATIC_CONSTANT(int, elements_per_char = bits_per_char / 2);
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|   typedef typename property_traits<IndexMap>::key_type key_type;
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|   typedef two_bit_color_type value_type;
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|   typedef void reference;
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|   typedef read_write_property_map_tag category;
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| 
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|   explicit two_bit_color_map(std::size_t n, const IndexMap& index = IndexMap())
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|     : n(n), index(index), data(new unsigned char[(n + elements_per_char - 1) / elements_per_char])
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|   {
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|     // Fill to white
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|     std::fill(data.get(), data.get() + (n + elements_per_char - 1) / elements_per_char, 0);
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|   }
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| };
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| 
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| template<typename IndexMap>
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| inline two_bit_color_type
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| get(const two_bit_color_map<IndexMap>& pm, 
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|     typename property_traits<IndexMap>::key_type key) 
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| {
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|   BOOST_STATIC_CONSTANT(int, elements_per_char = two_bit_color_map<IndexMap>::elements_per_char);
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|   typename property_traits<IndexMap>::value_type i = get(pm.index, key);
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|   BOOST_ASSERT ((std::size_t)i < pm.n);
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|   std::size_t byte_num = i / elements_per_char;
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|   std::size_t bit_position = ((i % elements_per_char) * 2);
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|   return two_bit_color_type((pm.data.get()[byte_num] >> bit_position) & 3);
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| }
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| 
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| template<typename IndexMap>
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| inline void
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| put(const two_bit_color_map<IndexMap>& pm, 
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|     typename property_traits<IndexMap>::key_type key,
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|     two_bit_color_type value)
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| {
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|   BOOST_STATIC_CONSTANT(int, elements_per_char = two_bit_color_map<IndexMap>::elements_per_char);
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|   typename property_traits<IndexMap>::value_type i = get(pm.index, key);
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|   BOOST_ASSERT ((std::size_t)i < pm.n);
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|   BOOST_ASSERT (value >= 0 && value < 4);
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|   std::size_t byte_num = i / elements_per_char;
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|   std::size_t bit_position = ((i % elements_per_char) * 2);
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|     pm.data.get()[byte_num] =
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|       (unsigned char)
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|         ((pm.data.get()[byte_num] & ~(3 << bit_position))
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|          | (value << bit_position));
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| }
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| 
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| template<typename IndexMap>
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| inline two_bit_color_map<IndexMap>
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| make_two_bit_color_map(std::size_t n, const IndexMap& index_map)
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| {
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|   return two_bit_color_map<IndexMap>(n, index_map);
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| }
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| 
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| } // end namespace boost
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| 
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| #endif // BOOST_TWO_BIT_COLOR_MAP_HPP
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| 
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| #ifdef BOOST_GRAPH_USE_MPI
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| #  include <boost/graph/distributed/two_bit_color_map.hpp>
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| #endif
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