]> git.lyx.org Git - lyx.git/blobdiff - src/Graph.cpp
Document NeedCProtect -1
[lyx.git] / src / Graph.cpp
index 8f2568b608260c79c2810eec7003a0cec0d610b7..0165bdacc9a4c95d626f21996f83f010c1a52959 100644 (file)
@@ -3,7 +3,8 @@
  * This file is part of LyX, the document processor.
  * Licence details can be found in the file COPYING.
  *
- * \author Dekel Tsur
+ * \author Dekel Tsur (original code)
+ * \author Richard Kimberly Heck (re-implementation)
  *
  * Full author contact details are available in file CREDITS.
  */
 #include "Graph.h"
 #include "Format.h"
 
-#include <algorithm>
+#include "support/debug.h"
+#include "support/lassert.h"
 
 using namespace std;
 
 namespace lyx {
 
 
-bool Graph::bfs_init(int s, bool clear_visited)
+bool Graph::bfs_init(int s, bool clear_visited, queue<int> & Q)
 {
        if (s < 0)
                return false;
 
-       Q_ = queue<int>();
+       if (!Q.empty())
+               Q = queue<int>();
 
        if (clear_visited) {
                vector<Vertex>::iterator it = vertices_.begin();
@@ -34,39 +37,40 @@ bool Graph::bfs_init(int s, bool clear_visited)
                        it->visited = false;
        }
        if (!vertices_[s].visited) {
-               Q_.push(s);
+               Q.push(s);
                vertices_[s].visited = true;
        }
        return true;
 }
 
 
-vector<int> const
-       Graph::getReachableTo(int target, bool clear_visited)
+Graph::EdgePath const
+       Graph::getReachableTo(int to, bool clear_visited)
 {
-       vector<int> result;
-       if (!bfs_init(target, clear_visited))
+       EdgePath result;
+       queue<int> Q;
+       if (!bfs_init(to, clear_visited, Q))
                return result;
 
        // Here's the logic, which is shared by the other routines.
-       // Q_ holds a list of nodes we have been able to reach (in this
+       // Q holds a list of nodes we have been able to reach (in this
        // case, reach backwards). It is initialized to the current node
        // by bfs_init, and then we recurse, adding the nodes we can reach
        // from the current node as we go. That makes it a breadth-first
        // search.
-       while (!Q_.empty()) {
-               int const current = Q_.front();
-               Q_.pop();
-               if (current != target || formats.get(target).name() != "lyx")
+       while (!Q.empty()) {
+               int const current = Q.front();
+               Q.pop();
+               if (current != to || theFormats().get(to).name() != "lyx")
                        result.push_back(current);
 
-               vector<Arrow>::iterator it = vertices_[current].in_arrows.begin();
-               vector<Arrow>::iterator const end = vertices_[current].in_arrows.end();
+               vector<Arrow *>::iterator it = vertices_[current].in_arrows.begin();
+               vector<Arrow *>::iterator const end = vertices_[current].in_arrows.end();
                for (; it != end; ++it) {
-                       const int cv = it->vertex;
+                       const int cv = (*it)->from;
                        if (!vertices_[cv].visited) {
                                vertices_[cv].visited = true;
-                               Q_.push(cv);
+                               Q.push(cv);
                        }
                }
        }
@@ -75,36 +79,38 @@ vector<int> const
 }
 
 
-vector<int> const
+Graph::EdgePath const
        Graph::getReachable(int from, bool only_viewable,
-               bool clear_visited)
+               bool clear_visited, set<int> excludes)
 {
-       vector<int> result;
-       if (!bfs_init(from, clear_visited))
+       EdgePath result;
+       queue<int> Q;
+       if (!bfs_init(from, clear_visited, Q))
                return result;
 
-       while (!Q_.empty()) {
-               int const current = Q_.front();
-               Q_.pop();
-               Format const & format = formats.get(current);
+       while (!Q.empty()) {
+               int const current = Q.front();
+               Q.pop();
+               Format const & format = theFormats().get(current);
                if (!only_viewable || !format.viewer().empty())
                        result.push_back(current);
                else if (format.isChildFormat()) {
                        Format const * const parent =
-                               formats.getFormat(format.parentFormat());
+                               theFormats().getFormat(format.parentFormat());
                        if (parent && !parent->viewer().empty())
                                result.push_back(current);
                }
 
-               vector<Arrow>::const_iterator cit =
+               vector<Arrow *>::const_iterator cit =
                        vertices_[current].out_arrows.begin();
-               vector<Arrow>::const_iterator end =
+               vector<Arrow *>::const_iterator end =
                        vertices_[current].out_arrows.end();
                for (; cit != end; ++cit) {
-                       int const cv = cit->vertex;
+                       int const cv = (*cit)->to;
                        if (!vertices_[cv].visited) {
                                vertices_[cv].visited = true;
-                               Q_.push(cv);
+                               if (excludes.find(cv) == excludes.end())
+                                       Q.push(cv);
                        }
                }
        }
@@ -118,24 +124,25 @@ bool Graph::isReachable(int from, int to)
        if (from == to)
                return true;
 
-       if (to < 0 || !bfs_init(from))
+       queue<int> Q;
+       if (to < 0 || !bfs_init(from, true, Q))
                return false;
 
-       while (!Q_.empty()) {
-               int const current = Q_.front();
-               Q_.pop();
+       while (!Q.empty()) {
+               int const current = Q.front();
+               Q.pop();
                if (current == to)
                        return true;
 
-               vector<Arrow>::const_iterator cit =
+               vector<Arrow *>::const_iterator cit =
                        vertices_[current].out_arrows.begin();
-               vector<Arrow>::const_iterator end =
+               vector<Arrow *>::const_iterator end =
                        vertices_[current].out_arrows.end();
                for (; cit != end; ++cit) {
-                       int const cv = cit->vertex;
+                       int const cv = (*cit)->to;
                        if (!vertices_[cv].visited) {
                                vertices_[cv].visited = true;
-                               Q_.push(cv);
+                               Q.push(cv);
                        }
                }
        }
@@ -146,68 +153,85 @@ bool Graph::isReachable(int from, int to)
 
 Graph::EdgePath const Graph::getPath(int from, int to)
 {
-       EdgePath path;
        if (from == to)
-               return path;
+               return EdgePath();
 
-       if (to < 0 || !bfs_init(from))
-               return path;
+       queue<int> Q;
+       if (to < 0 || !bfs_init(from, true, Q))
+               return EdgePath();
 
-       // pair<vertex, edge>
-       vector<pair<int, int> > prev(vertices_.size());
+       vector<EdgePath> pathes;
+       pathes.resize(vertices_.size());
+       while (!Q.empty()) {
+               int const current = Q.front();
+               Q.pop();
 
-       bool found = false;
-       while (!Q_.empty()) {
-               int const current = Q_.front();
-               Q_.pop();
-
-               vector<Arrow>::const_iterator const beg =
+               vector<Arrow *>::const_iterator cit =
                        vertices_[current].out_arrows.begin();
-               vector<Arrow>::const_iterator cit = beg;
-               vector<Arrow>::const_iterator end =
+               vector<Arrow *>::const_iterator end =
                        vertices_[current].out_arrows.end();
                for (; cit != end; ++cit) {
-                       int const cv = cit->vertex;
+                       int const cv = (*cit)->to;
                        if (!vertices_[cv].visited) {
                                vertices_[cv].visited = true;
-                               Q_.push(cv);
-                               // FIXME This will not do for finding multiple paths.
-                               // Perhaps we need a vector, or a set. We'll also want
-                               // to add this info, even if the node is visited, so
-                               // outside this conditional.
-                               prev[cv] = pair<int, int>(current, cit->edge);
+                               Q.push(cv);
+                               // NOTE If we wanted to collect all the paths, then
+                               // we just need to collect them here and not worry
+                               // about "visited".
+                               EdgePath lastpath = pathes[(*cit)->from];
+                               lastpath.push_back((*cit)->id);
+                               pathes[cv] = lastpath;
                        }
                        if (cv == to) {
-                               found = true;
-                               break;
+                               return pathes[cv];
                        }
                }
        }
-       if (!found)
-               return path;
-
-       while (to != from) {
-               path.push_back(prev[to].second);
-               to = prev[to].first;
-       }
-       reverse(path.begin(), path.end());
-       return path;
+       // failure
+       return EdgePath();
 }
 
-       
+
 void Graph::init(int size)
 {
        vertices_ = vector<Vertex>(size);
+       arrows_.clear();
        numedges_ = 0;
 }
 
 
 void Graph::addEdge(int from, int to)
 {
-       vertices_[to].in_arrows.push_back(Arrow(from, numedges_));
-       vertices_[from].out_arrows.push_back(Arrow(to, numedges_));
-       ++numedges_;
+       arrows_.push_back(Arrow(from, to, numedges_));
+       numedges_++;
+       Arrow * ar = &(arrows_.back());
+       vertices_[to].in_arrows.push_back(ar);
+       vertices_[from].out_arrows.push_back(ar);
+}
+
+
+// At present, we do not need this debugging code, but
+// I am going to leave it here in case we need it again.
+#if 0
+void Graph::dumpGraph() const
+{
+       vector<Vertex>::const_iterator it = vertices_.begin();
+       vector<Vertex>::const_iterator en = vertices_.end();
+       for (; it != en; ++it) {
+               LYXERR0("Next vertex...");
+               LYXERR0("In arrows...");
+               std::vector<Arrow *>::const_iterator iit = it->in_arrows.begin();
+               std::vector<Arrow *>::const_iterator ien = it->in_arrows.end();
+               for (; iit != ien; ++iit)
+                       LYXERR0("From " << (*iit)->from << " to " << (*iit)->to);
+               LYXERR0("Out arrows...");
+               iit = it->out_arrows.begin();
+               ien = it->out_arrows.end();
+               for (; iit != ien; ++iit)
+                       LYXERR0("From " << (*iit)->from << " to " << (*iit)->to);
+       }
 }
+#endif
 
 
 } // namespace lyx