4 * This file is part of LyX, the document processor.
5 * Licence details can be found in the file COPYING.
7 * \author Dekel Tsur (original code)
8 * \author Richard Heck (re-implementation)
10 * Full author contact details are available in file CREDITS.
16 #include "support/mutex.h"
26 /// Represents a directed graph, possibly with multiple edges
27 /// connecting the vertices.
30 Graph() : numedges_(0) {}
32 typedef std::vector<int> EdgePath;
33 /// \return a vector of the vertices from which "to" can be reached
34 std::vector<int> const getReachableTo(int to, bool clear_visited);
35 /// \return a vector of the vertices that can be reached from "from"
36 std::vector<int> const
37 getReachable(int from, bool only_viewable, bool clear_visited);
38 /// can "from" be reached from "to"?
39 bool isReachable(int from, int to);
40 /// find a path from "from" to "to". always returns one of the
41 /// shortest such paths.
42 EdgePath const getPath(int from, int to);
43 /// called repeatedly to build the graph
44 void addEdge(int from, int to);
45 /// reset the internal data structures
50 bool bfs_init(int, bool clear_visited = true);
51 /// clears the paths from a previous search. should be
52 /// called before each new one.
54 /// used to recover a marked path
55 void getMarkedPath(int from, int to, EdgePath & path);
56 /// these represent the arrows connecting the nodes of the graph.
57 /// this is the basic representation of the graph: as a bunch of
61 Arrow(int f, int t, int i):
62 from(f), to(t), id(i) {}
63 /// the vertex at the tail of the arrow
65 /// the vertex at the head
67 /// an id for this arrow, e.g., for use in describing paths
71 /// a container for the arrows
72 /// we use a list because we want pointers to the arrows,
73 /// and a vector might invalidate them
74 typedef std::list<Arrow> Arrows;
76 /// Represents a vertex of the graph. Note that we could recover
77 /// the in_arrows and out_arrows from the Arrows, so these are in
78 /// effect a kind of cache.
80 /// arrows that point at this one
81 std::vector<Arrow *> in_arrows;
82 /// arrows out from here
83 std::vector<Arrow *> out_arrows;
84 /// used in the search routines
89 /// a container for the vertices
90 /// the index into the vector functions as the identifier by which
91 /// these are referenced in the Arrow struct
92 /// the code making use of the Graph must keep track of the relation
93 /// between these indices and the objects they represent. (in the case
94 /// of Format, this is easy, since the Format objects already have ints
96 std::vector<Vertex> vertices_;
99 /// a counter that we use to assign id's to the arrows
100 /// FIXME This technique assumes a correspondence between the
101 /// ids of the arrows and ids associated with Converters that
102 /// seems kind of fragile. Perhaps a better solution would be
103 /// to pass the ids as we create the arrows.
106 /// make public functions thread save