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
25static struct nine_range *
26nine_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
52static inline struct nine_range *
53nine_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
65static inline void
66nine_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
78void
79nine_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