1 /* Copyright (c) 2008 The Board of Trustees of The Leland Stanford
4 * We are making the OpenFlow specification and associated documentation
5 * (Software) available for public use and benefit with the expectation
6 * that others will use, modify and enhance the Software and contribute
7 * those enhancements back to the community. However, since we would
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9 * restrictions as possible permission is hereby granted, free of
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13 * distribute, sublicense, and/or sell copies of the Software, and to
14 * permit persons to whom the Software is furnished to do so, subject to
15 * the following conditions:
17 * The above copyright notice and this permission notice shall be
18 * included in all copies or substantial portions of the Software.
20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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24 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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29 * The name and trademarks of copyright holder(s) may NOT be used in
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31 * derivatives without specific, written prior permission.
35 #include "port-array.h"
37 static struct port_array_l2 l2_sentinel;
38 static struct port_array_l3 l3_sentinel;
41 /* Initializes 'pa' as an empty port_array. */
43 port_array_init(struct port_array *pa)
48 for (i = 0; i < PORT_ARRAY_L2_SIZE; i++) {
49 l2_sentinel.l2[i] = &l3_sentinel;
52 for (i = 0; i < PORT_ARRAY_L1_SIZE; i++) {
53 pa->l1[i] = &l2_sentinel;
57 /* Sets 'pa' element numbered 'idx' to 'p'. */
59 port_array_set(struct port_array *pa, uint16_t idx, void *p)
61 struct port_array_l2 **l2p, *l2;
62 struct port_array_l3 **l3p, *l3;
64 /* Traverse level 1. */
65 l2p = &pa->l1[PORT_ARRAY_L1(idx)];
66 if (*l2p == &l2_sentinel) {
67 *l2p = xmemdup(&l2_sentinel, sizeof l2_sentinel);
71 /* Traverse level 2. */
72 l3p = &l2->l2[PORT_ARRAY_L2(idx)];
73 if (*l3p == &l3_sentinel) {
74 *l3p = xmemdup(&l3_sentinel, sizeof l3_sentinel);
79 l3->l3[PORT_ARRAY_L3(idx)] = p;
83 next(const struct port_array *pa, unsigned int *idxp)
85 unsigned int idx = *idxp;
87 /* Using shift-right directly here, instead of PORT_ARRAY_L1(idx), ensures
88 * that with an initially too-big value of '*idxp' we will skip the outer
89 * loop and return NULL. */
90 unsigned int l1_idx = idx >> PORT_ARRAY_L1_SHIFT;
91 unsigned int l2_idx = PORT_ARRAY_L2(idx);
92 unsigned int l3_idx = PORT_ARRAY_L3(idx);
93 while (l1_idx < PORT_ARRAY_L1_SIZE) {
94 struct port_array_l2 *l2 = pa->l1[l1_idx];
95 if (l2 != &l2_sentinel) {
96 while (l2_idx < PORT_ARRAY_L2_SIZE) {
97 struct port_array_l3 *l3 = l2->l2[l2_idx];
98 if (l3 != &l3_sentinel) {
99 while (l3_idx < PORT_ARRAY_L3_SIZE) {
100 void *p = l3->l3[l3_idx];
102 *idxp = ((l1_idx << PORT_ARRAY_L1_SHIFT)
103 | (l2_idx << PORT_ARRAY_L2_SHIFT)
104 | (l3_idx << PORT_ARRAY_L3_SHIFT));
118 *idxp = PORT_ARRAY_SIZE;
122 /* Returns the value of the lowest-numbered non-empty element of 'pa', and sets
123 * '*idxp' to that element's index. If 'pa' is entirely empty, returns a null
124 * pointer and sets '*idxp' to 65536. */
126 port_array_first(const struct port_array *pa, unsigned int *idxp)
129 return next(pa, idxp);
132 /* Returns the value of the lowest-numbered non-empty element of 'pa' greater
133 * than the initial value of '*idxp', and sets '*idxp' to that element's index.
134 * If 'pa' contains no non-empty elements with indexes greater than the initial
135 * value of '*idxp', returns a null pointer and sets '*idxp' to 65536. */
137 port_array_next(const struct port_array *pa, unsigned int *idxp)
140 return next(pa, idxp);