Commit | Line | Data |
---|---|---|
5966417e | 1 | /* |
ab5be9fa | 2 | * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
5966417e | 3 | * |
ab5be9fa | 4 | * SPDX-License-Identifier: LGPL-2.1-only |
5966417e | 5 | * |
5966417e JG |
6 | */ |
7 | ||
8 | #include <common/dynamic-buffer.h> | |
5966417e JG |
9 | #include <common/utils.h> |
10 | #include <assert.h> | |
11 | ||
df94ef0f JG |
12 | /* |
13 | * Round to (upper) power of two, val is returned if it already is a power of | |
14 | * two. | |
15 | */ | |
5966417e JG |
16 | static |
17 | size_t round_to_power_of_2(size_t val) | |
18 | { | |
19 | int order; | |
20 | size_t rounded; | |
21 | ||
22 | order = utils_get_count_order_u64(val); | |
23 | assert(order >= 0); | |
24 | rounded = (1ULL << order); | |
25 | assert(rounded >= val); | |
26 | ||
27 | return rounded; | |
28 | } | |
29 | ||
c90647fe | 30 | LTTNG_HIDDEN |
5966417e JG |
31 | void lttng_dynamic_buffer_init(struct lttng_dynamic_buffer *buffer) |
32 | { | |
33 | assert(buffer); | |
34 | memset(buffer, 0, sizeof(*buffer)); | |
35 | } | |
36 | ||
c90647fe | 37 | LTTNG_HIDDEN |
5966417e JG |
38 | int lttng_dynamic_buffer_append(struct lttng_dynamic_buffer *buffer, |
39 | const void *buf, size_t len) | |
40 | { | |
41 | int ret = 0; | |
42 | ||
43 | if (!buffer || (!buf && len)) { | |
44 | ret = -1; | |
45 | goto end; | |
46 | } | |
47 | ||
48 | if (len == 0) { | |
49 | /* Not an error, no-op. */ | |
50 | goto end; | |
51 | } | |
52 | ||
63557623 JG |
53 | assert(buffer->_capacity >= buffer->size); |
54 | if (buffer->_capacity < (len + buffer->size)) { | |
5966417e | 55 | ret = lttng_dynamic_buffer_set_capacity(buffer, |
63557623 JG |
56 | buffer->_capacity + |
57 | (len - (buffer->_capacity - buffer->size))); | |
5966417e JG |
58 | if (ret) { |
59 | goto end; | |
60 | } | |
61 | } | |
62 | ||
63 | memcpy(buffer->data + buffer->size, buf, len); | |
64 | buffer->size += len; | |
65 | end: | |
66 | return ret; | |
67 | } | |
68 | ||
c90647fe | 69 | LTTNG_HIDDEN |
5966417e JG |
70 | int lttng_dynamic_buffer_append_buffer(struct lttng_dynamic_buffer *dst_buffer, |
71 | struct lttng_dynamic_buffer *src_buffer) | |
72 | { | |
73 | int ret; | |
74 | ||
75 | if (!dst_buffer || !src_buffer) { | |
76 | ret = -1; | |
77 | goto end; | |
78 | } | |
79 | ||
80 | ret = lttng_dynamic_buffer_append(dst_buffer, src_buffer->data, | |
81 | src_buffer->size); | |
82 | end: | |
83 | return ret; | |
84 | } | |
85 | ||
c90647fe | 86 | LTTNG_HIDDEN |
5966417e JG |
87 | int lttng_dynamic_buffer_set_size(struct lttng_dynamic_buffer *buffer, |
88 | size_t new_size) | |
89 | { | |
90 | int ret = 0; | |
91 | ||
92 | if (!buffer) { | |
93 | goto end; | |
94 | } | |
95 | ||
96 | if (new_size == buffer->size) { | |
97 | goto end; | |
98 | } | |
99 | ||
63557623 | 100 | if (new_size > buffer->_capacity) { |
5966417e JG |
101 | ret = lttng_dynamic_buffer_set_capacity(buffer, new_size); |
102 | if (ret) { | |
103 | goto end; | |
104 | } | |
1c6def05 | 105 | |
6ee96b4d | 106 | memset(buffer->data + buffer->size, 0, new_size - buffer->size); |
5966417e JG |
107 | } else if (new_size > buffer->size) { |
108 | memset(buffer->data + buffer->size, 0, new_size - buffer->size); | |
109 | } else { | |
110 | /* | |
111 | * Shrinking size. There is no need to zero-out the newly | |
112 | * released memory as it will either be: | |
113 | * - overwritten by lttng_dynamic_buffer_append, | |
114 | * - expanded later, which will zero-out the memory | |
115 | * | |
116 | * Users of external APIs are encouraged to set the buffer's | |
117 | * size _before_ making such calls. | |
118 | */ | |
119 | } | |
120 | buffer->size = new_size; | |
121 | end: | |
122 | return ret; | |
123 | } | |
124 | ||
c90647fe | 125 | LTTNG_HIDDEN |
5966417e | 126 | int lttng_dynamic_buffer_set_capacity(struct lttng_dynamic_buffer *buffer, |
fc804d0f | 127 | size_t demanded_capacity) |
5966417e JG |
128 | { |
129 | int ret = 0; | |
fc804d0f | 130 | void *new_buf; |
e9347dad JG |
131 | size_t new_capacity = demanded_capacity ? |
132 | round_to_power_of_2(demanded_capacity) : 0; | |
5966417e | 133 | |
fc804d0f JG |
134 | if (!buffer || demanded_capacity < buffer->size) { |
135 | /* | |
136 | * Shrinking a buffer's size by changing its capacity is | |
137 | * unsupported. | |
138 | */ | |
5966417e JG |
139 | ret = -1; |
140 | goto end; | |
141 | } | |
142 | ||
63557623 | 143 | if (new_capacity == buffer->_capacity) { |
5966417e JG |
144 | goto end; |
145 | } | |
146 | ||
fc804d0f JG |
147 | /* Memory is initialized by the size increases. */ |
148 | new_buf = realloc(buffer->data, new_capacity); | |
149 | if (!new_buf) { | |
150 | ret = -1; | |
151 | goto end; | |
5966417e | 152 | } |
fc804d0f | 153 | buffer->data = new_buf; |
63557623 | 154 | buffer->_capacity = new_capacity; |
5966417e JG |
155 | end: |
156 | return ret; | |
157 | } | |
158 | ||
159 | /* Release any memory used by the dynamic buffer. */ | |
c90647fe | 160 | LTTNG_HIDDEN |
5966417e JG |
161 | void lttng_dynamic_buffer_reset(struct lttng_dynamic_buffer *buffer) |
162 | { | |
163 | if (!buffer) { | |
164 | return; | |
165 | } | |
166 | buffer->size = 0; | |
63557623 | 167 | buffer->_capacity = 0; |
5966417e JG |
168 | free(buffer->data); |
169 | } | |
201bd415 JG |
170 | |
171 | LTTNG_HIDDEN | |
172 | size_t lttng_dynamic_buffer_get_capacity_left( | |
173 | struct lttng_dynamic_buffer *buffer) | |
174 | { | |
175 | if (!buffer) { | |
176 | return 0; | |
177 | } | |
178 | return buffer->_capacity - buffer->size; | |
179 | } |