vppinfra: move unused code to extras/deprecated/vppinfra
[vpp.git] / extras / deprecated / vppinfra / fheap.h
diff --git a/extras/deprecated/vppinfra/fheap.h b/extras/deprecated/vppinfra/fheap.h
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+/*
+ * 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.
+ */
+#ifndef included_clib_fheap_h
+#define included_clib_fheap_h
+
+/* Fibonacci Heaps Fredman, M. L.; Tarjan (1987).
+   "Fibonacci heaps and their uses in improved network optimization algorithms" */
+
+#include <vppinfra/vec.h>
+
+typedef struct
+{
+  /* Node index of parent. */
+  u32 parent;
+
+  /* Node index of first child. */
+  u32 first_child;
+
+  /* Next and previous nodes in doubly linked list of siblings. */
+  u32 next_sibling, prev_sibling;
+
+  /* Key (distance) for this node.  Parent always has key
+     <= than keys of children. */
+  u32 key;
+
+  /* Number of children (as opposed to descendents). */
+  u32 rank;
+
+  u32 is_marked;
+
+  /* Set to one when node is inserted; zero when deleted. */
+  u32 is_valid;
+} fheap_node_t;
+
+#define foreach_fheap_node_sibling(f,ni,first_ni,body)                 \
+do {                                                                   \
+  u32 __fheap_foreach_first_ni = (first_ni);                           \
+  u32 __fheap_foreach_ni = __fheap_foreach_first_ni;                   \
+  u32 __fheap_foreach_next_ni;                                         \
+  fheap_node_t * __fheap_foreach_n;                                    \
+  if (__fheap_foreach_ni != ~0)                                                \
+    while (1)                                                          \
+      {                                                                        \
+       __fheap_foreach_n = fheap_get_node ((f), __fheap_foreach_ni);   \
+       __fheap_foreach_next_ni = __fheap_foreach_n -> next_sibling;    \
+       (ni) = __fheap_foreach_ni;                                      \
+                                                                       \
+       body;                                                           \
+                                                                       \
+       /* End of circular list? */                                     \
+       if (__fheap_foreach_next_ni == __fheap_foreach_first_ni)        \
+         break;                                                        \
+                                                                       \
+       __fheap_foreach_ni = __fheap_foreach_next_ni;                   \
+                                                                       \
+      }                                                                        \
+} while (0)
+
+typedef struct
+{
+  u32 min_root;
+
+  /* Vector of nodes. */
+  fheap_node_t *nodes;
+
+  u32 *root_list_by_rank;
+
+  u32 enable_validate;
+
+  u32 validate_serial;
+} fheap_t;
+
+/* Initialize empty heap. */
+always_inline void
+fheap_init (fheap_t * f, u32 n_nodes)
+{
+  fheap_node_t *save_nodes = f->nodes;
+  u32 *save_root_list = f->root_list_by_rank;
+
+  clib_memset (f, 0, sizeof (f[0]));
+
+  f->nodes = save_nodes;
+  f->root_list_by_rank = save_root_list;
+
+  vec_validate (f->nodes, n_nodes - 1);
+  vec_reset_length (f->root_list_by_rank);
+
+  f->min_root = ~0;
+}
+
+always_inline void
+fheap_free (fheap_t * f)
+{
+  vec_free (f->nodes);
+  vec_free (f->root_list_by_rank);
+}
+
+always_inline u32
+fheap_find_min (fheap_t * f)
+{
+  return f->min_root;
+}
+
+always_inline u32
+fheap_is_empty (fheap_t * f)
+{
+  return f->min_root == ~0;
+}
+
+/* Add/delete nodes. */
+void fheap_add (fheap_t * f, u32 ni, u32 key);
+void fheap_del (fheap_t * f, u32 ni);
+
+/* Delete and return minimum. */
+u32 fheap_del_min (fheap_t * f, u32 * min_key);
+
+/* Change key value. */
+void fheap_decrease_key (fheap_t * f, u32 ni, u32 new_key);
+
+#endif /* included_clib_fheap_h */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */