X-Git-Url: https://git.lyx.org/gitweb/?a=blobdiff_plain;f=src%2FGraph.cpp;h=036bb38857359e6d8a6f78b8c568b97ca6d8c89e;hb=eba2f14fa79b7078788d813d2d2c2dc3d481be13;hp=1f5c66ed83275d93cb53afe699531ca64e463c82;hpb=9383f4c3c6f9cfab2d658701ba66e2b54cd68bea;p=lyx.git

diff --git a/src/Graph.cpp b/src/Graph.cpp
index 1f5c66ed83..036bb38857 100644
--- a/src/Graph.cpp
+++ b/src/Graph.cpp
@@ -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 Heck (re-implementation)
  *
  * Full author contact details are available in file CREDITS.
  */
@@ -13,6 +14,9 @@
 #include "Graph.h"
 #include "Format.h"
 
+#include "support/debug.h"
+#include "support/lassert.h"
+
 #include <algorithm>
 
 using namespace std;
@@ -20,44 +24,55 @@ using namespace std;
 namespace lyx {
 
 
-int Graph::bfs_init(int s, bool clear_visited)
+bool Graph::bfs_init(int s, bool clear_visited, queue<int> & Q)
 {
 	if (s < 0)
-		return s;
+		return false;
 
-	Q_ = std::queue<int>();
+	if (!Q.empty())
+		Q = queue<int>();
 
-	if (clear_visited)
-		fill(visited_.begin(), visited_.end(), false);
-	if (visited_[s] == false) {
-		Q_.push(s);
-		visited_[s] = true;
+	if (clear_visited) {
+		vector<Vertex>::iterator it = vertices_.begin();
+		vector<Vertex>::iterator en = vertices_.end();
+		for (; it != en; ++it)
+			it->visited = false;
 	}
-	return s;
+	if (!vertices_[s].visited) {
+		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 target, bool clear_visited)
 {
-	vector<int> result;
-	int const s = bfs_init(target, clear_visited);
-	if (s < 0)
+	EdgePath result;
+	queue<int> Q;
+	if (!bfs_init(target, clear_visited, Q))
 		return result;
 
-	while (!Q_.empty()) {
-		int const i = Q_.front();
-		Q_.pop();
-		if (i != s || formats.get(target).name() != "lyx") {
-			result.push_back(i);
-		}
-
-		vector<int>::iterator it = vertices_[i].in_vertices.begin();
-		vector<int>::iterator end = vertices_[i].in_vertices.end();
+	// 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
+	// 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 || theFormats().get(target).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();
 		for (; it != end; ++it) {
-			if (!visited_[*it]) {
-				visited_[*it] = true;
-				Q_.push(*it);
+			const int cv = (*it)->from;
+			if (!vertices_[cv].visited) {
+				vertices_[cv].visited = true;
+				Q.push(cv);
 			}
 		}
 	}
@@ -66,36 +81,40 @@ Graph::getReachableTo(int target, bool clear_visited)
 }
 
 
-vector<int> const
-Graph::getReachable(int from, bool only_viewable,
-		    bool clear_visited)
+Graph::EdgePath const
+	Graph::getReachable(int from, bool only_viewable,
+		bool clear_visited, set<int> excludes)
 {
-	vector<int> result;
-	if (bfs_init(from, clear_visited) < 0)
+	EdgePath result;
+	queue<int> Q;
+	if (!bfs_init(from, clear_visited, Q))
 		return result;
 
-	while (!Q_.empty()) {
-		int const i = Q_.front();
-		Q_.pop();
-		Format const & format = formats.get(i);
+	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(i);
+			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(i);
+				result.push_back(current);
 		}
 
-		vector<int>::const_iterator cit =
-			vertices_[i].out_vertices.begin();
-		vector<int>::const_iterator end =
-			vertices_[i].out_vertices.end();
-		for (; cit != end; ++cit)
-			if (!visited_[*cit]) {
-				visited_[*cit] = true;
-				Q_.push(*cit);
+		vector<Arrow *>::const_iterator cit =
+			vertices_[current].out_arrows.begin();
+		vector<Arrow *>::const_iterator end =
+			vertices_[current].out_arrows.end();
+		for (; cit != end; ++cit) {
+			int const cv = (*cit)->to;
+			if (!vertices_[cv].visited) {
+				vertices_[cv].visited = true;
+				if (excludes.find(cv) == excludes.end())
+					Q.push(cv);
 			}
+		}
 	}
 
 	return result;
@@ -107,24 +126,25 @@ bool Graph::isReachable(int from, int to)
 	if (from == to)
 		return true;
 
-	int const s = bfs_init(from);
-	if (s < 0 || to < 0)
+	queue<int> Q;
+	if (to < 0 || !bfs_init(from, true, Q))
 		return false;
 
-	while (!Q_.empty()) {
-		int const i = Q_.front();
-		Q_.pop();
-		if (i == to)
+	while (!Q.empty()) {
+		int const current = Q.front();
+		Q.pop();
+		if (current == to)
 			return true;
 
-		vector<int>::const_iterator cit =
-			vertices_[i].out_vertices.begin();
-		vector<int>::const_iterator end =
-			vertices_[i].out_vertices.end();
+		vector<Arrow *>::const_iterator cit =
+			vertices_[current].out_arrows.begin();
+		vector<Arrow *>::const_iterator end =
+			vertices_[current].out_arrows.end();
 		for (; cit != end; ++cit) {
-			if (!visited_[*cit]) {
-				visited_[*cit] = true;
-				Q_.push(*cit);
+			int const cv = (*cit)->to;
+			if (!vertices_[cv].visited) {
+				vertices_[cv].visited = true;
+				Q.push(cv);
 			}
 		}
 	}
@@ -133,70 +153,87 @@ bool Graph::isReachable(int from, int to)
 }
 
 
-Graph::EdgePath const
-Graph::getPath(int from, int t)
+Graph::EdgePath const Graph::getPath(int from, int to)
 {
-	EdgePath path;
-	if (from == t)
-		return path;
-
-	int const s = bfs_init(from);
-	if (s < 0 || t < 0)
-		return path;
-
-	vector<int> prev_edge(formats.size());
-	vector<int> prev_vertex(formats.size());
-
-	bool found = false;
-	while (!Q_.empty()) {
-		int const i = Q_.front();
-		Q_.pop();
-		if (i == t) {
-			found = true;
-			break;
-		}
-
-		vector<int>::const_iterator beg =
-			vertices_[i].out_vertices.begin();
-		vector<int>::const_iterator cit = beg;
-		vector<int>::const_iterator end =
-			vertices_[i].out_vertices.end();
-		for (; cit != end; ++cit)
-			if (!visited_[*cit]) {
-				int const j = *cit;
-				visited_[j] = true;
-				Q_.push(j);
-				int const k = cit - beg;
-				prev_edge[j] = vertices_[i].out_edges[k];
-				prev_vertex[j] = i;
+	if (from == to)
+		return EdgePath();
+
+	queue<int> Q;
+	if (to < 0 || !bfs_init(from, true, Q))
+		return EdgePath();
+
+	vector<EdgePath> pathes;
+	pathes.resize(vertices_.size());
+	while (!Q.empty()) {
+		int const current = Q.front();
+		Q.pop();
+
+		vector<Arrow *>::const_iterator cit =
+			vertices_[current].out_arrows.begin();
+		vector<Arrow *>::const_iterator end =
+			vertices_[current].out_arrows.end();
+		for (; cit != end; ++cit) {
+			int const cv = (*cit)->to;
+			if (!vertices_[cv].visited) {
+				vertices_[cv].visited = true;
+				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) {
+				return pathes[cv];
+			}
+		}
 	}
-	if (!found)
-		return path;
-
-	while (t != s) {
-		path.push_back(prev_edge[t]);
-		t = prev_vertex[t];
-	}
-	reverse(path.begin(), path.end());
-	return path;
+	// failure
+	return EdgePath();
 }
 
+
 void Graph::init(int size)
 {
 	vertices_ = vector<Vertex>(size);
-	visited_.resize(size);
+	arrows_.clear();
 	numedges_ = 0;
 }
 
-void Graph::addEdge(int s, int t)
+
+void Graph::addEdge(int from, int to)
 {
-	vertices_[t].in_vertices.push_back(s);
-	vertices_[s].out_vertices.push_back(t);
-	vertices_[s].out_edges.push_back(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);
 }
 
-vector<Graph::Vertex> Graph::vertices_;
+
+// 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