1 /*
2 * Copyright 2013 Christoph Bumiller
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * on the rights to use, copy, modify, merge, publish, distribute, sub
8 * license, and/or sell copies of the Software, and to permit persons to whom
9 * the Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
19 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
20 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
21 * USE OR OTHER DEALINGS IN THE SOFTWARE. */
22
23 #include "nine_helpers.h"
24
25 static struct nine_range *
nine_range_pool_more(struct nine_range_pool * pool)26 nine_range_pool_more(struct nine_range_pool *pool)
27 {
28 struct nine_range *r = MALLOC(64 * sizeof(struct nine_range));
29 int i;
30 assert(!pool->free);
31
32 if (pool->num_slabs == pool->num_slabs_max) {
33 unsigned p = pool->num_slabs_max;
34 unsigned n = pool->num_slabs_max * 2;
35 if (!n)
36 n = 4;
37 pool->slabs = REALLOC(pool->slabs,
38 p * sizeof(struct nine_range *),
39 n * sizeof(struct nine_range *));
40 pool->num_slabs_max = n;
41 }
42 pool->free = pool->slabs[pool->num_slabs++] = r;
43
44 for (i = 0; i < 63; ++i, r = r->next)
45 r->next = (struct nine_range *)
46 ((uint8_t *)r + sizeof(struct nine_range));
47 r->next = NULL;
48
49 return pool->free;
50 }
51
52 static inline struct nine_range *
nine_range_pool_get(struct nine_range_pool * pool,int16_t bgn,int16_t end)53 nine_range_pool_get(struct nine_range_pool *pool, int16_t bgn, int16_t end)
54 {
55 struct nine_range *r = pool->free;
56 if (!r)
57 r = nine_range_pool_more(pool);
58 assert(r);
59 pool->free = r->next;
60 r->bgn = bgn;
61 r->end = end;
62 return r;
63 }
64
65 static inline void
nine_ranges_coalesce(struct nine_range * r,struct nine_range_pool * pool)66 nine_ranges_coalesce(struct nine_range *r, struct nine_range_pool *pool)
67 {
68 struct nine_range *n;
69
70 while (r->next && r->end >= r->next->bgn) {
71 n = r->next->next;
72 r->end = (r->end >= r->next->end) ? r->end : r->next->end;
73 nine_range_pool_put(pool, r->next);
74 r->next = n;
75 }
76 }
77
78 void
nine_ranges_insert(struct nine_range ** head,int16_t bgn,int16_t end,struct nine_range_pool * pool)79 nine_ranges_insert(struct nine_range **head, int16_t bgn, int16_t end,
80 struct nine_range_pool *pool)
81 {
82 struct nine_range *r, **pn = head;
83
84 for (r = *head; r && bgn > r->end; pn = &r->next, r = r->next);
85
86 if (!r || end < r->bgn) {
87 *pn = nine_range_pool_get(pool, bgn, end);
88 (*pn)->next = r;
89 } else
90 if (bgn < r->bgn) {
91 r->bgn = bgn;
92 if (end > r->end)
93 r->end = end;
94 nine_ranges_coalesce(r, pool);
95 } else
96 if (end > r->end) {
97 r->end = end;
98 nine_ranges_coalesce(r, pool);
99 }
100 }
101