add Eina_Graph_DFS

5 files changed, 293 insertions, 2 deletions

diff --git a/src/Makefile_lib.am b/src/Makefile_lib.am
index 79b3b8a..0e806d3 100644
--- a/src/Makefile_lib.am
+++ b/src/Makefile_lib.am
@@ -3,11 +3,13 @@
 includesdir = $(includedir)/eina_graph-@VMAJ@
 includes_HEADERS = \
    lib/Eina_Graph.h \
-   lib/eina_graph.h
+   lib/eina_graph.h \
+   lib/eina_graph_dfs.h
 
 lib_libeina_graph_la_SOURCES = \
    lib/eina_graph_main.c \
-   lib/eina_graph.c
+   lib/eina_graph.c \
+   lib/eina_graph_dfs.c
 
 EXTRA_DIST += lib/eina_graph_private.h
 
diff --git a/src/lib/Eina_Graph.h b/src/lib/Eina_Graph.h
index e5dbf0b..84e4abf 100644
--- a/src/lib/Eina_Graph.h
+++ b/src/lib/Eina_Graph.h
@@ -58,5 +58,6 @@ EAPI int
 eina_graph_shutdown(void);
 
 #include <eina_graph.h>
+#include <eina_graph_dfs.h>
 
 #endif   /* _EINA_GRAPH_MAIN_H */
diff --git a/src/lib/eina_graph_dfs.c b/src/lib/eina_graph_dfs.c
new file mode 100644
index 0000000..3fa08a6
--- /dev/null
+++ b/src/lib/eina_graph_dfs.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_dfs.h>
+#include "eina_graph_private.h"
+
+static void
+_eina_graph_dfs_swalk(_Eina_Graph *_g, _Eina_Graph_DFS *_dfs, unsigned int v)
+{
+   Eina_List *stack = NULL;
+   Eina_Graph_Adjacents *adjs;
+   unsigned int p, w, n, i;
+
+   p = v;
+   stack = eina_list_prepend(stack, (void *) v);
+
+   while (eina_list_count(stack) > 0)
+     {
+        w = (unsigned int) eina_list_data_get(stack);
+        stack = eina_list_remove(stack, (void *) w);
+
+        if(_dfs->marked[w]) continue;
+        _dfs->marked[w] = EINA_TRUE;
+        _dfs->edge_to[w] = p;
+        p = w;
+      
+        adjs = &_g->adjs[w];
+        n = adjs->count;
+        for (i = 0; i < n; i++)
+          {
+             w =  adjs->data[i];
+             if (!_dfs->marked[w])
+               {
+                  stack = eina_list_prepend(stack, (void *) w);
+               }
+          }
+     }
+}
+
+static void
+_eina_graph_dfs_rwalk(_Eina_Graph *_g, _Eina_Graph_DFS *_dfs, unsigned int v)
+{
+   Eina_Graph_Adjacents *adjs;
+   unsigned int i, n, w;
+
+   _dfs->marked[v] = EINA_TRUE;
+
+   adjs = &_g->adjs[v];
+   n = adjs->count;
+   for (i = 0; i < n; i++)
+     {
+        w =  adjs->data[i];
+        if (!_dfs->marked[w])
+          {
+             _eina_graph_dfs_rwalk(_g, _dfs, w);
+             _dfs->edge_to[w] = v;
+          }
+     }
+}
+
+EAPI Eina_Graph_DFS *
+eina_graph_dfs_new(Eina_Graph *g, unsigned int s, Eina_Bool r)
+{
+   _Eina_Graph_DFS *_dfs;
+   _Eina_Graph * _g = (_Eina_Graph *) g;
+
+   _dfs = calloc(1, sizeof(_Eina_Graph_DFS));
+   if (!_dfs)
+     goto error_dfs;
+
+   _dfs->marked = calloc(_g->vertices, sizeof(Eina_Bool));
+   if (!_dfs->marked)
+     goto error_marked;
+
+   _dfs->edge_to = calloc(_g->vertices, sizeof(unsigned int));
+   if (!_dfs->edge_to)
+     goto error_edge_to;
+
+   _dfs->s = s;
+   _dfs->vertices = _g->vertices;
+
+   if (r)
+     _eina_graph_dfs_rwalk(_g, _dfs, s);
+   else
+     _eina_graph_dfs_swalk(_g, _dfs, s);
+
+   return (Eina_Graph_DFS *) _dfs;
+
+error_edge_to:
+   free(_dfs->marked);
+error_marked:
+   free(_dfs);
+error_dfs:
+   ERR("calloc failed : %s", strerror(errno));
+   return NULL;
+}
+
+EAPI void
+eina_graph_dfs_free(Eina_Graph_DFS *dfs)
+{
+   _Eina_Graph_DFS *_dfs = (_Eina_Graph_DFS *) dfs;
+
+   free(_dfs->marked);
+   free(_dfs->edge_to);
+   free(_dfs);
+}
+
+EAPI unsigned int
+eina_graph_dfs_source(Eina_Graph_DFS *dfs)
+{
+   _Eina_Graph_DFS *_dfs = (_Eina_Graph_DFS *) dfs;
+
+   return _dfs->s;
+}
+
+EAPI Eina_Bool
+eina_graph_dfs_has_path_to(Eina_Graph_DFS *dfs, unsigned int v)
+{
+   _Eina_Graph_DFS *_dfs = (_Eina_Graph_DFS *) dfs;
+
+   if (v >= _dfs->vertices)
+     {
+        ERR("%u is out of [0;%u[", v, _dfs->vertices);
+        return EINA_FALSE;
+     }
+
+   return _dfs->marked[v];
+}
+
+EAPI Eina_List *
+eina_graph_dfs_path_to(Eina_Graph_DFS *dfs, unsigned int v)
+{
+   unsigned int w = v;
+   Eina_List *path = NULL;
+   _Eina_Graph_DFS *_dfs = (_Eina_Graph_DFS *) dfs;
+
+   if (v >= _dfs->vertices)
+     {
+        ERR("%u is out of [0;%u[", v, _dfs->vertices);
+        return NULL;
+     }
+
+   if (!_dfs->marked[v])
+     return NULL;
+
+   while (w != _dfs->s)
+     {
+        path = eina_list_prepend(path, (void *) w);
+        w = _dfs->edge_to[w];
+     }
+   path = eina_list_prepend(path, (void *) _dfs->s);
+
+   return path;
+}
+
diff --git a/src/lib/eina_graph_dfs.h b/src/lib/eina_graph_dfs.h
new file mode 100644
index 0000000..7e596d6
--- /dev/null
+++ b/src/lib/eina_graph_dfs.h
@@ -0,0 +1,96 @@
+/* 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.
+ */
+
+#ifndef _EINA_GRAPH_DFS_H
+#define _EINA_GRAPH_DFS_H
+
+#include <eina_list.h>
+#include <eina_graph.h>
+
+/**
+ * @typedef Eina_Graph_DFS
+ * The basic Eina_Graph DFS type.
+ */
+typedef struct _Eina_Graph_DFS_Opaque Eina_Graph_DFS;
+
+/**
+ * returns a Depth First Search of the given graph.
+ *
+ * @param g the graph to build the DFS from.
+ * @param s the source vertex of the DFS.
+ * @param r if est to EINA_TRUE, use recursive instead of stack based algo.
+ *
+ * @return a new Depth First Search.
+ */
+EAPI Eina_Graph_DFS *
+eina_graph_dfs_new(Eina_Graph *g, unsigned int s, Eina_Bool r);
+
+/**
+ * free the given graph DFS.
+ *
+ * @param dfs the graph DFS to free.
+ */
+EAPI void
+eina_graph_dfs_free(Eina_Graph_DFS *dfs);
+
+/**
+ * get the source vertex of the graph DFS.
+ *
+ * @param dfs the graph DFS to consider.
+ *
+ * @return the source vertex of the DFS.
+ */
+EAPI unsigned int
+eina_graph_dfs_source(Eina_Graph_DFS *dfs);
+
+/**
+ * is there a path from the source to the given vertex.
+ *
+ * @param dfs the graph DFS to consider.
+ * @param v the vertex to test if there is a path to.
+ *
+ * @return EINA_TRUE if the vertex is reachable from the source.
+ */
+EAPI Eina_Bool
+eina_graph_dfs_has_path_to(Eina_Graph_DFS *dfs, unsigned int v);
+
+/*
+ * return the path to reach the given vertex from the source.
+ *
+ * the Eina_list returned must be freed by the user code.
+ *
+ * @param dfs the graph DFS to consider.
+ * @param v the vertex to test if there is a path to.
+ *
+ * @return a list of vertices to follwo from source to reach v,
+ * NULL if v is not reachable.
+ */
+EAPI Eina_List *
+eina_graph_dfs_path_to(Eina_Graph_DFS *dfs, unsigned int v);
+
+#endif   /* _EINA_GRAPH_DFS_H */
diff --git a/src/lib/eina_graph_private.h b/src/lib/eina_graph_private.h
index 75dfffb..d7a676c 100644
--- a/src/lib/eina_graph_private.h
+++ b/src/lib/eina_graph_private.h
@@ -98,4 +98,12 @@ typedef struct _Eina_Graph
    Eina_Graph_Adjacents *adjs;
 } _Eina_Graph;
 
+typedef struct _Eina_Graph_DFS
+{
+    unsigned int s;
+    unsigned int vertices;
+    Eina_Bool *marked;
+    unsigned int *edge_to;
+} _Eina_Graph_DFS;
+
 #endif   /* _EINA_GRAPH_PRIVATE_H */