1 files changed, 198 insertions, 0 deletions
diff --git a/vppinfra/vppinfra/test_ptclosure.c b/vppinfra/vppinfra/test_ptclosure.c
new file mode 100644
index 00000000000..b5ac13f7de5
--- /dev/null
+++ b/vppinfra/vppinfra/test_ptclosure.c
@@ -0,0 +1,198 @@
+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <vppinfra/ptclosure.h>
+#include <vppinfra/hash.h>
+
+typedef struct {
+  uword * index_by_name;
+  u8 * items;
+} test_main_t;
+
+test_main_t test_main;
+
+static char * items [] = {
+    "d",
+    "a",
+    "b",
+    "c",
+};
+
+char * constraints [] = {
+    "a,b",
+    "b,c",
+    "d,b",
+    //    "c,a", /* no partial order possible */
+};
+
+u32 vl(void *p)
+{
+  return vec_len (p);
+}
+
+static void dump_closure (test_main_t * tm, char * s, u8 ** orig)
+{
+  int i, j;
+
+  fformat (stdout, "--------- %s --------------\n", s);
+  for (i = 0; i < vec_len (orig); i++)
+    {
+      for (j = 0; j < vec_len (orig); j++)
+        if (orig[i][j])
+          {
+            fformat (stdout, "%s <before> %s\n", items[i], items[j]);
+          }
+    }
+}
+
+int comma_split (u8 *s, u8 **a, u8 **b)
+{
+  *a = s;
+
+  while (*s && *s != ',')
+    s++;
+
+  if (*s == ',')
+    *s = 0;
+  else
+    return 1;
+
+  *b = (u8 *) (s+1);
+  return 0;
+}
+
+int test_ptclosure_main (unformat_input_t * input)
+{
+  test_main_t * tm = &test_main;
+  u8 * item_name;
+  int i, j;
+  u8 ** orig;
+  u8 ** closure;
+  u8 * a_name, * b_name;
+  int a_index, b_index;
+  uword * p;
+  u8 * this_constraint;
+  int n;
+  u32 * result = 0;
+
+  tm->index_by_name = hash_create_string (0, sizeof (uword));
+
+  n = ARRAY_LEN(items);
+
+  for (i = 0; i < n; i++)
+    {
+      item_name = (u8 *) items[i];
+      hash_set_mem (tm->index_by_name, item_name, i);
+    }
+
+  orig = clib_ptclosure_alloc (n);
+
+  for (i = 0; i < ARRAY_LEN(constraints); i++)
+    {
+      this_constraint = format (0, "%s%c", constraints[i], 0);
+      
+      if (comma_split (this_constraint, &a_name, &b_name))
+        {
+          clib_warning ("couldn't split '%s'", constraints[i]);
+          return 1;
+        }
+      
+      p = hash_get_mem (tm->index_by_name, a_name);
+      if (p == 0)
+        {
+          clib_warning ("couldn't find '%s'", a_name);
+          return 1;
+        }
+      a_index = p[0];
+
+      p = hash_get_mem (tm->index_by_name, b_name);
+      if (p == 0)
+        {
+          clib_warning ("couldn't find '%s'", b_name);
+          return 1;
+        }
+      b_index = p[0];
+
+      orig[a_index][b_index] = 1;
+      vec_free (this_constraint);
+    }
+  
+  dump_closure (tm, "original relation", orig);
+
+  closure = clib_ptclosure (orig);
+
+  dump_closure (tm, "closure", closure);
+
+  /* 
+   * Output partial order
+   */
+
+ again:
+  for (i = 0; i < n; i++)
+    {
+      for (j = 0; j < n; j++)
+        {
+          if (closure[i][j])
+            goto item_constrained;
+        }
+      /* Item i can be output */
+      vec_add1 (result, i);
+      {
+        int k;
+        for (k = 0; k < n; k++)
+          closure [k][i] = 0;
+        /* "Magic" a before a, to keep from ever outputting it again */
+        closure [i][i] = 1;
+        goto again;
+      }
+    item_constrained:
+      ;
+    }
+
+  if (vec_len (result) != n)
+    {
+      clib_warning ("no partial order exists");
+      exit (1);
+    }
+
+  fformat (stdout, "Partial order:\n");
+
+  for (i = vec_len(result)-1; i >= 0; i--)
+    {
+      fformat (stdout, "%s\n", items[result[i]]);
+    }
+
+  vec_free (result);
+  clib_ptclosure_free (orig);
+  clib_ptclosure_free (closure);
+
+  return 0;
+}
+
+#ifdef CLIB_UNIX
+int main (int argc, char * argv[])
+{
+  unformat_input_t i;
+  int ret;
+
+  clib_mem_init (0, 3ULL<<30);
+
+  unformat_init_command_line (&i, argv);
+  ret = test_ptclosure_main (&i);
+  unformat_free (&i);
+
+  return ret;
+}
+#endif /* CLIB_UNIX */