053d093524
Type: improvement Signed-off-by: Dave Barach <dave@barachs.net> Change-Id: Id28299a188feefa1899d835fd499f018af95d81b
141 lines
3.3 KiB
C
141 lines
3.3 KiB
C
/*
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* Copyright (c) 2015 Cisco and/or its affiliates.
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef included_clib_fheap_h
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#define included_clib_fheap_h
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/* Fibonacci Heaps Fredman, M. L.; Tarjan (1987).
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"Fibonacci heaps and their uses in improved network optimization algorithms" */
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#include <vppinfra/vec.h>
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typedef struct
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{
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/* Node index of parent. */
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u32 parent;
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/* Node index of first child. */
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u32 first_child;
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/* Next and previous nodes in doubly linked list of siblings. */
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u32 next_sibling, prev_sibling;
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/* Key (distance) for this node. Parent always has key
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<= than keys of children. */
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u32 key;
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/* Number of children (as opposed to descendents). */
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u32 rank;
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u32 is_marked;
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/* Set to one when node is inserted; zero when deleted. */
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u32 is_valid;
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} fheap_node_t;
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#define foreach_fheap_node_sibling(f,ni,first_ni,body) \
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do { \
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u32 __fheap_foreach_first_ni = (first_ni); \
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u32 __fheap_foreach_ni = __fheap_foreach_first_ni; \
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u32 __fheap_foreach_next_ni; \
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fheap_node_t * __fheap_foreach_n; \
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if (__fheap_foreach_ni != ~0) \
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while (1) \
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{ \
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__fheap_foreach_n = fheap_get_node ((f), __fheap_foreach_ni); \
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__fheap_foreach_next_ni = __fheap_foreach_n -> next_sibling; \
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(ni) = __fheap_foreach_ni; \
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\
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body; \
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\
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/* End of circular list? */ \
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if (__fheap_foreach_next_ni == __fheap_foreach_first_ni) \
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break; \
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\
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__fheap_foreach_ni = __fheap_foreach_next_ni; \
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\
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} \
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} while (0)
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typedef struct
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{
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u32 min_root;
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/* Vector of nodes. */
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fheap_node_t *nodes;
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u32 *root_list_by_rank;
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u32 enable_validate;
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u32 validate_serial;
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} fheap_t;
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/* Initialize empty heap. */
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always_inline void
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fheap_init (fheap_t * f, u32 n_nodes)
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{
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fheap_node_t *save_nodes = f->nodes;
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u32 *save_root_list = f->root_list_by_rank;
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clib_memset (f, 0, sizeof (f[0]));
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f->nodes = save_nodes;
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f->root_list_by_rank = save_root_list;
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vec_validate (f->nodes, n_nodes - 1);
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vec_reset_length (f->root_list_by_rank);
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f->min_root = ~0;
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}
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always_inline void
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fheap_free (fheap_t * f)
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{
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vec_free (f->nodes);
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vec_free (f->root_list_by_rank);
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}
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always_inline u32
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fheap_find_min (fheap_t * f)
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{
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return f->min_root;
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}
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always_inline u32
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fheap_is_empty (fheap_t * f)
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{
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return f->min_root == ~0;
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}
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/* Add/delete nodes. */
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void fheap_add (fheap_t * f, u32 ni, u32 key);
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void fheap_del (fheap_t * f, u32 ni);
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/* Delete and return minimum. */
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u32 fheap_del_min (fheap_t * f, u32 * min_key);
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/* Change key value. */
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void fheap_decrease_key (fheap_t * f, u32 ni, u32 new_key);
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#endif /* included_clib_fheap_h */
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/*
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* fd.io coding-style-patch-verification: ON
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*
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* Local Variables:
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* eval: (c-set-style "gnu")
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* End:
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*/
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