src/graph.C

   1 /**
   2  * \file graph.C
   3  * This file is part of LyX, the document processor.
   4  * Licence details can be found in the file COPYING.
   5  *
   6  * \author Dekel Tsur
   7  *
   8  * Full author contact details are available in file CREDITS.
   9  */
  10
  11 #include "config.h"
  12 #include "graph.h"
  13 #include "format.h"
  14
  15 #include <queue>
  16 #include <vector>
  17 #include <algorithm>
  18
  19 using std::queue;
  20 using std::vector;
  21
  22
  23 int Graph::bfs_init(int s, bool clear_visited)
  24 {
  25         if (s < 0)
  26                 return s;
  27
  28         Q_ = std::queue<int>();
  29
  30         if (clear_visited)
  31                 fill(visited_.begin(), visited_.end(), false);
  32         if (visited_[s] == false) {
  33                 Q_.push(s);
  34                 visited_[s] = true;
  35         }
  36         return s;
  37 }
  38
  39
  40 vector<int> const
  41 Graph::getReachableTo(int target, bool clear_visited)
  42 {
  43         vector<int> result;
  44         int const s = bfs_init(target, clear_visited);
  45         if (s < 0)
  46                 return result;
  47
  48         while (!Q_.empty()) {
  49                 int const i = Q_.front();
  50                 Q_.pop();
  51                 if (i != s || formats.get(target).name() != "lyx") {
  52                         result.push_back(i);
  53                 }
  54
  55                 vector<int>::iterator it = vertices_[i].in_vertices.begin();
  56                 vector<int>::iterator end = vertices_[i].in_vertices.end();
  57                 for (; it != end; ++it) {
  58                         if (!visited_[*it]) {
  59                                 visited_[*it] = true;
  60                                 Q_.push(*it);
  61                         }
  62                 }
  63         }
  64
  65         return result;
  66 }
  67
  68
  69 vector<int> const
  70 Graph::getReachable(int from, bool only_viewable,
  71                     bool clear_visited)
  72 {
  73         vector<int> result;
  74         if (bfs_init(from, clear_visited) < 0)
  75                 return result;
  76
  77         while (!Q_.empty()) {
  78                 int const i = Q_.front();
  79                 Q_.pop();
  80                 Format const & format = formats.get(i);
  81                 if (format.name() == "lyx")
  82                         continue;
  83                 if (!only_viewable || !format.viewer().empty() ||
  84                     format.isChildFormat())
  85                         result.push_back(i);
  86
  87                 vector<int>::const_iterator cit =
  88                         vertices_[i].out_vertices.begin();
  89                 vector<int>::const_iterator end =
  90                         vertices_[i].out_vertices.end();
  91                 for (; cit != end; ++cit)
  92                         if (!visited_[*cit]) {
  93                                 visited_[*cit] = true;
  94                                 Q_.push(*cit);
  95                         }
  96         }
  97
  98         return result;
  99 }
 100
 101
 102 bool Graph::isReachable(int from, int to)
 103 {
 104         if (from == to)
 105                 return true;
 106
 107         int const s = bfs_init(from);
 108         if (s < 0 || to < 0)
 109                 return false;
 110
 111         while (!Q_.empty()) {
 112                 int const i = Q_.front();
 113                 Q_.pop();
 114                 if (i == to)
 115                         return true;
 116
 117                 vector<int>::const_iterator cit =
 118                         vertices_[i].out_vertices.begin();
 119                 vector<int>::const_iterator end =
 120                         vertices_[i].out_vertices.end();
 121                 for (; cit != end; ++cit) {
 122                         if (!visited_[*cit]) {
 123                                 visited_[*cit] = true;
 124                                 Q_.push(*cit);
 125                         }
 126                 }
 127         }
 128
 129         return false;
 130 }
 131
 132
 133 Graph::EdgePath const
 134 Graph::getPath(int from, int t)
 135 {
 136         EdgePath path;
 137         if (from == t)
 138                 return path;
 139
 140         int const s = bfs_init(from);
 141         if (s < 0 || t < 0)
 142                 return path;
 143
 144         vector<int> prev_edge(formats.size());
 145         vector<int> prev_vertex(formats.size());
 146
 147         bool found = false;
 148         while (!Q_.empty()) {
 149                 int const i = Q_.front();
 150                 Q_.pop();
 151                 if (i == t) {
 152                         found = true;
 153                         break;
 154                 }
 155
 156                 vector<int>::const_iterator beg =
 157                         vertices_[i].out_vertices.begin();
 158                 vector<int>::const_iterator cit = beg;
 159                 vector<int>::const_iterator end =
 160                         vertices_[i].out_vertices.end();
 161                 for (; cit != end; ++cit)
 162                         if (!visited_[*cit]) {
 163                                 int const j = *cit;
 164                                 visited_[j] = true;
 165                                 Q_.push(j);
 166                                 int const k = cit - beg;
 167                                 prev_edge[j] = vertices_[i].out_edges[k];
 168                                 prev_vertex[j] = i;
 169                         }
 170         }
 171         if (!found)
 172                 return path;
 173
 174         while (t != s) {
 175                 path.push_back(prev_edge[t]);
 176                 t = prev_vertex[t];
 177         }
 178         reverse(path.begin(), path.end());
 179         return path;
 180 }
 181
 182 void Graph::init(int size)
 183 {
 184         vertices_ = vector<Vertex>(size);
 185         visited_.resize(size);
 186         numedges_ = 0;
 187 }
 188
 189 void Graph::addEdge(int s, int t)
 190 {
 191         vertices_[t].in_vertices.push_back(s);
 192         vertices_[s].out_vertices.push_back(t);
 193         vertices_[s].out_edges.push_back(numedges_++);
 194 }
 195
 196 vector<Graph::Vertex> Graph::vertices_;