xref: /third_party/mesa3d/src/util/u_vector.h (revision bf215546) 
1/*
2 * Copyright © 2015 Intel Corporation
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 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * 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 NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24/*
25 * u_vector is a vector based queue for storing arbitrary
26 * sized arrays of objects without using a linked list.
27 */
28
29#ifndef U_VECTOR_H
30#define U_VECTOR_H
31
32#include <stdint.h>
33#include <stdlib.h>
34#include "util/macros.h"
35#include "util/u_math.h"
36
37#ifdef __cplusplus
38extern "C" {
39#endif
40
41/* TODO - move to u_math.h - name it better etc */
42static inline uint32_t
43u_align_u32(uint32_t v, uint32_t a)
44{
45   assert(a != 0 && a == (a & -((int32_t) a)));
46   return (v + a - 1) & ~(a - 1);
47}
48
49struct u_vector {
50   uint32_t head;
51   uint32_t tail;
52   uint32_t element_size;
53   uint32_t size;
54   void *data;
55};
56
57int u_vector_init_pow2(struct u_vector *queue,
58                       uint32_t initial_element_count,
59                       uint32_t element_size);
60
61void *u_vector_add(struct u_vector *queue);
62void *u_vector_remove(struct u_vector *queue);
63
64static inline int
65u_vector_init(struct u_vector *queue,
66              uint32_t initial_element_count,
67              uint32_t element_size)
68{
69   initial_element_count = util_next_power_of_two(initial_element_count);
70   element_size = util_next_power_of_two(element_size);
71   return u_vector_init_pow2(queue, initial_element_count, element_size);
72}
73
74static inline int
75u_vector_length(struct u_vector *queue)
76{
77   return (queue->head - queue->tail) / queue->element_size;
78}
79
80static inline void *
81u_vector_head(struct u_vector *vector)
82{
83   assert(vector->tail < vector->head);
84   return (void *)((char *)vector->data +
85                   ((vector->head - vector->element_size) &
86                    (vector->size - 1)));
87}
88
89static inline void *
90u_vector_tail(struct u_vector *vector)
91{
92   return (void *)((char *)vector->data + (vector->tail & (vector->size - 1)));
93}
94
95static inline void
96u_vector_finish(struct u_vector *queue)
97{
98   free(queue->data);
99}
100
101#ifdef __cplusplus
102#define u_vector_element_cast(elem) (decltype(elem))
103#else
104#define u_vector_element_cast(elem) (void *)
105#endif
106
107#define u_vector_foreach(elem, queue)                                  \
108   STATIC_ASSERT(__builtin_types_compatible_p(__typeof__(queue), struct u_vector *)); \
109   for (uint32_t __u_vector_offset = (queue)->tail;                                \
110        elem = u_vector_element_cast(elem)((char *)(queue)->data + \
111                                           (__u_vector_offset & ((queue)->size - 1))), \
112           __u_vector_offset != (queue)->head;                          \
113        __u_vector_offset += (queue)->element_size)
114
115#ifdef __cplusplus
116}
117#endif
118
119#endif
120
121