add Eina_Graph_BFS

1 files changed, 184 insertions, 0 deletions

diff --git a/src/lib/eina_graph_bfs.c b/src/lib/eina_graph_bfs.c
new file mode 100644
index 0000000..36cbdbc
--- /dev/null
+++ b/src/lib/eina_graph_bfs.c
@@ -0,0 +1,184 @@
+/* EINA_GRAPH - EFL graph processing library
+ * Copyright (C) 2013 Jérémy Zurcher
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies of the Software and its Copyright notices. In addition publicly
+ * documented acknowledgment must be given that this software has been used if no
+ * source code of this software is made available publicly. This includes
+ * acknowledgments in either Copyright notices, Manuals, Publicity and Marketing
+ * documents or any documentation provided with any product containing this
+ * software. This License does not apply to any software that links to the
+ * libraries provided by this software (statically or dynamically), but only to
+ * the software provided.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+#include <eina_graph_bfs.h>
+#include "eina_graph_private.h"
+
+static void
+_eina_graph_bfs_fwalk(_Eina_Graph *_g, _Eina_Graph_BFS *_bfs, unsigned int v)
+{
+   Eina_List *fifo = NULL;
+   Eina_Graph_Adjacents *adjs;
+   unsigned int p, w, n, i, d;
+
+   d = 0;
+   _bfs->marked[v] = EINA_TRUE;
+   _bfs->edge_to[v] = v;
+   _bfs->dist_to[v] = d;
+   fifo = eina_list_append(fifo, CAST_V(v));
+
+   while (eina_list_count(fifo) > 0)
+     {
+        w = CAST_D(eina_list_data_get(fifo));
+        fifo = eina_list_remove(fifo, CAST_V(w));
+
+        p = w;
+        d++;
+
+        adjs = &_g->adjs[w];
+        n = adjs->count;
+        for (i = 0; i < n; i++)
+          {
+             w =  adjs->data[i];
+             if (!_bfs->marked[w])
+               {
+                  _bfs->marked[w] = EINA_TRUE;
+                  _bfs->edge_to[w] = p;
+                  _bfs->dist_to[w] = d;
+                  fifo = eina_list_append(fifo, CAST_V(w));
+               }
+          }
+     }
+}
+
+EAPI Eina_Graph_BFS *
+eina_graph_bfs_new(Eina_Graph *g, unsigned int s)
+{
+   _Eina_Graph_BFS *_bfs;
+   _Eina_Graph * _g = (_Eina_Graph *) g;
+
+   _bfs = calloc(1, sizeof(_Eina_Graph_BFS));
+   if (!_bfs)
+     goto error_bfs;
+
+   _bfs->marked = calloc(_g->vertices, sizeof(Eina_Bool));
+   if (!_bfs->marked)
+     goto error_marked;
+
+   _bfs->edge_to = calloc(_g->vertices, sizeof(unsigned int));
+   if (!_bfs->edge_to)
+     goto error_edge_to;
+
+   _bfs->dist_to = calloc(_g->vertices, sizeof(unsigned int));
+   if (!_bfs->dist_to)
+     goto error_dist_to;
+
+   _bfs->s = s;
+   _bfs->vertices = _g->vertices;
+
+   _eina_graph_bfs_fwalk(_g, _bfs, s);
+
+   return (Eina_Graph_BFS *) _bfs;
+
+error_dist_to:
+   free(_bfs->edge_to);
+error_edge_to:
+   free(_bfs->marked);
+error_marked:
+   free(_bfs);
+error_bfs:
+   ERR("calloc failed : %s", strerror(errno));
+   return NULL;
+}
+
+EAPI void
+eina_graph_bfs_free(Eina_Graph_BFS *bfs)
+{
+   _Eina_Graph_BFS *_bfs = (_Eina_Graph_BFS *) bfs;
+
+   free(_bfs->marked);
+   free(_bfs->edge_to);
+   free(_bfs->dist_to);
+   free(_bfs);
+}
+
+EAPI unsigned int
+eina_graph_bfs_source(Eina_Graph_BFS *bfs)
+{
+   _Eina_Graph_BFS *_bfs = (_Eina_Graph_BFS *) bfs;
+
+   return _bfs->s;
+}
+
+EAPI Eina_Bool
+eina_graph_bfs_has_path_to(Eina_Graph_BFS *bfs, unsigned int v)
+{
+   _Eina_Graph_BFS *_bfs = (_Eina_Graph_BFS *) bfs;
+
+   if (v >= _bfs->vertices)
+     {
+        ERR("%u is out of [0;%u[", v, _bfs->vertices);
+        return EINA_FALSE;
+     }
+
+   return _bfs->marked[v];
+}
+
+EAPI Eina_List *
+eina_graph_bfs_path_to(Eina_Graph_BFS *bfs, unsigned int v)
+{
+   unsigned int w = v;
+   Eina_List *path = NULL;
+   _Eina_Graph_BFS *_bfs = (_Eina_Graph_BFS *) bfs;
+
+   if (v >= _bfs->vertices)
+     {
+        ERR("%u is out of [0;%u[", v, _bfs->vertices);
+        return NULL;
+     }
+
+   if (!_bfs->marked[v])
+     return NULL;
+
+   while (w != _bfs->s)
+     {
+        path = eina_list_prepend(path, CAST_V(w));
+        w = _bfs->edge_to[w];
+     }
+   path = eina_list_prepend(path, CAST_V(_bfs->s));
+
+   return path;
+}
+
+EAPI unsigned int
+eina_graph_bfs_dist_to(Eina_Graph_BFS *bfs, unsigned int v)
+{
+   _Eina_Graph_BFS *_bfs = (_Eina_Graph_BFS *) bfs;
+
+   if (v >= _bfs->vertices)
+     {
+        ERR("%u is out of [0;%u[", v, _bfs->vertices);
+        return UINT_MAX;
+     }
+
+   return _bfs->dist_to[v];
+}