1 /*
2 * Copyright (c) 2011 Intel Corporation. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 *
32 */
33
34 #if !defined(INDEXER_H)
35 #define INDEXER_H
36
37 #include <config.h>
38 #include <stddef.h>
39 #include <sys/types.h>
40
41 /*
42 * Indexer - to find a structure given an index. Synchronization
43 * must be provided by the caller. Caller must initialize the
44 * indexer by setting free_list and size to 0.
45 */
46
47 union idx_entry {
48 void *item;
49 int next;
50 };
51
52 #define IDX_INDEX_BITS 16
53 #define IDX_ENTRY_BITS 10
54 #define IDX_ENTRY_SIZE (1 << IDX_ENTRY_BITS)
55 #define IDX_ARRAY_SIZE (1 << (IDX_INDEX_BITS - IDX_ENTRY_BITS))
56 #define IDX_MAX_INDEX ((1 << IDX_INDEX_BITS) - 1)
57
58 struct indexer
59 {
60 union idx_entry *array[IDX_ARRAY_SIZE];
61 int free_list;
62 int size;
63 };
64
65 #define idx_array_index(index) (index >> IDX_ENTRY_BITS)
66 #define idx_entry_index(index) (index & (IDX_ENTRY_SIZE - 1))
67
68 int idx_insert(struct indexer *idx, void *item);
69 void *idx_remove(struct indexer *idx, int index);
70 void idx_replace(struct indexer *idx, int index, void *item);
71
idx_at(struct indexer * idx,int index)72 static inline void *idx_at(struct indexer *idx, int index)
73 {
74 return (idx->array[idx_array_index(index)] + idx_entry_index(index))->item;
75 }
76
77 /*
78 * Index map - associates a structure with an index. Synchronization
79 * must be provided by the caller. Caller must initialize the
80 * index map by setting it to 0.
81 */
82
83 struct index_map
84 {
85 void **array[IDX_ARRAY_SIZE];
86 };
87
88 int idm_set(struct index_map *idm, int index, void *item);
89 void *idm_clear(struct index_map *idm, int index);
90
idm_at(struct index_map * idm,int index)91 static inline void *idm_at(struct index_map *idm, int index)
92 {
93 void **entry;
94 entry = idm->array[idx_array_index(index)];
95 return entry[idx_entry_index(index)];
96 }
97
idm_lookup(struct index_map * idm,int index)98 static inline void *idm_lookup(struct index_map *idm, int index)
99 {
100 return ((index <= IDX_MAX_INDEX) && idm->array[idx_array_index(index)]) ?
101 idm_at(idm, index) : NULL;
102 }
103
104 typedef struct _dlist_entry {
105 struct _dlist_entry *next;
106 struct _dlist_entry *prev;
107 } dlist_entry;
108
dlist_init(dlist_entry * head)109 static inline void dlist_init(dlist_entry *head)
110 {
111 head->next = head;
112 head->prev = head;
113 }
114
dlist_empty(dlist_entry * head)115 static inline int dlist_empty(dlist_entry *head)
116 {
117 return head->next == head;
118 }
119
dlist_insert_after(dlist_entry * item,dlist_entry * head)120 static inline void dlist_insert_after(dlist_entry *item, dlist_entry *head)
121 {
122 item->next = head->next;
123 item->prev = head;
124 head->next->prev = item;
125 head->next = item;
126 }
127
dlist_insert_before(dlist_entry * item,dlist_entry * head)128 static inline void dlist_insert_before(dlist_entry *item, dlist_entry *head)
129 {
130 dlist_insert_after(item, head->prev);
131 }
132
133 #define dlist_insert_head dlist_insert_after
134 #define dlist_insert_tail dlist_insert_before
135
dlist_remove(dlist_entry * item)136 static inline void dlist_remove(dlist_entry *item)
137 {
138 item->prev->next = item->next;
139 item->next->prev = item->prev;
140 }
141
142 #endif /* INDEXER_H */
143