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1 | // Boost.Geometry Index | |
2 | // | |
3 | // R-tree iterator visitor implementation | |
4 | // | |
5 | // Copyright (c) 2011-2015 Adam Wulkiewicz, Lodz, Poland. | |
6 | // | |
7 | // Use, modification and distribution is subject to the Boost Software License, | |
8 | // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at | |
9 | // http://www.boost.org/LICENSE_1_0.txt) | |
10 | ||
11 | #ifndef BOOST_GEOMETRY_INDEX_DETAIL_RTREE_VISITORS_ITERATOR_HPP | |
12 | #define BOOST_GEOMETRY_INDEX_DETAIL_RTREE_VISITORS_ITERATOR_HPP | |
13 | ||
14 | namespace boost { namespace geometry { namespace index { | |
15 | ||
16 | namespace detail { namespace rtree { namespace visitors { | |
17 | ||
18 | template <typename Value, typename Options, typename Translator, typename Box, typename Allocators> | |
19 | class iterator | |
20 | : public rtree::visitor<Value, typename Options::parameters_type, Box, Allocators, typename Options::node_tag, true>::type | |
21 | { | |
22 | public: | |
23 | typedef typename rtree::node<Value, typename Options::parameters_type, Box, Allocators, typename Options::node_tag>::type node; | |
24 | typedef typename rtree::internal_node<Value, typename Options::parameters_type, Box, Allocators, typename Options::node_tag>::type internal_node; | |
25 | typedef typename rtree::leaf<Value, typename Options::parameters_type, Box, Allocators, typename Options::node_tag>::type leaf; | |
26 | ||
27 | typedef typename Allocators::size_type size_type; | |
28 | typedef typename Allocators::const_reference const_reference; | |
29 | typedef typename Allocators::node_pointer node_pointer; | |
30 | ||
31 | typedef typename rtree::elements_type<internal_node>::type::const_iterator internal_iterator; | |
32 | typedef typename rtree::elements_type<leaf>::type leaf_elements; | |
33 | typedef typename rtree::elements_type<leaf>::type::const_iterator leaf_iterator; | |
34 | ||
35 | inline iterator() | |
36 | : m_values(NULL) | |
37 | , m_current() | |
38 | {} | |
39 | ||
40 | inline void operator()(internal_node const& n) | |
41 | { | |
42 | typedef typename rtree::elements_type<internal_node>::type elements_type; | |
43 | elements_type const& elements = rtree::elements(n); | |
44 | ||
45 | m_internal_stack.push_back(std::make_pair(elements.begin(), elements.end())); | |
46 | } | |
47 | ||
48 | inline void operator()(leaf const& n) | |
49 | { | |
50 | m_values = ::boost::addressof(rtree::elements(n)); | |
51 | m_current = rtree::elements(n).begin(); | |
52 | } | |
53 | ||
54 | const_reference dereference() const | |
55 | { | |
56 | BOOST_GEOMETRY_INDEX_ASSERT(m_values, "not dereferencable"); | |
57 | return *m_current; | |
58 | } | |
59 | ||
60 | void initialize(node_pointer root) | |
61 | { | |
62 | rtree::apply_visitor(*this, *root); | |
63 | search_value(); | |
64 | } | |
65 | ||
66 | void increment() | |
67 | { | |
68 | ++m_current; | |
69 | search_value(); | |
70 | } | |
71 | ||
72 | void search_value() | |
73 | { | |
74 | for (;;) | |
75 | { | |
76 | // if leaf is choosen, move to the next value in leaf | |
77 | if ( m_values ) | |
78 | { | |
79 | // there are more values in the current leaf | |
80 | if ( m_current != m_values->end() ) | |
81 | { | |
82 | return; | |
83 | } | |
84 | // no more values, clear current leaf | |
85 | else | |
86 | { | |
87 | m_values = 0; | |
88 | } | |
89 | } | |
90 | // if leaf isn't choosen, move to the next leaf | |
91 | else | |
92 | { | |
93 | // return if there is no more nodes to traverse | |
94 | if ( m_internal_stack.empty() ) | |
95 | return; | |
96 | ||
97 | // no more children in current node, remove it from stack | |
98 | if ( m_internal_stack.back().first == m_internal_stack.back().second ) | |
99 | { | |
100 | m_internal_stack.pop_back(); | |
101 | continue; | |
102 | } | |
103 | ||
104 | internal_iterator it = m_internal_stack.back().first; | |
105 | ++m_internal_stack.back().first; | |
106 | ||
107 | // push the next node to the stack | |
108 | rtree::apply_visitor(*this, *(it->second)); | |
109 | } | |
110 | } | |
111 | } | |
112 | ||
113 | bool is_end() const | |
114 | { | |
115 | return 0 == m_values; | |
116 | } | |
117 | ||
118 | friend bool operator==(iterator const& l, iterator const& r) | |
119 | { | |
120 | return (l.m_values == r.m_values) && (0 == l.m_values || l.m_current == r.m_current ); | |
121 | } | |
122 | ||
123 | private: | |
124 | ||
125 | std::vector< std::pair<internal_iterator, internal_iterator> > m_internal_stack; | |
126 | const leaf_elements * m_values; | |
127 | leaf_iterator m_current; | |
128 | }; | |
129 | ||
130 | }}} // namespace detail::rtree::visitors | |
131 | ||
132 | }}} // namespace boost::geometry::index | |
133 | ||
134 | #endif // BOOST_GEOMETRY_INDEX_DETAIL_RTREE_VISITORS_ITERATOR_HPP |