diff options
Diffstat (limited to 'src/include/gnunet_buffer_lib.h')
-rw-r--r-- | src/include/gnunet_buffer_lib.h | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/src/include/gnunet_buffer_lib.h b/src/include/gnunet_buffer_lib.h new file mode 100644 index 000000000..c0ae06d77 --- /dev/null +++ b/src/include/gnunet_buffer_lib.h | |||
@@ -0,0 +1,176 @@ | |||
1 | /* | ||
2 | This file is part of GNUnet. | ||
3 | Copyright (C) 2020 GNUnet e.V. | ||
4 | |||
5 | GNUnet is free software: you can redistribute it and/or modify it | ||
6 | under the terms of the GNU Affero General Public License as published | ||
7 | by the Free Software Foundation, either version 3 of the License, | ||
8 | or (at your option) any later version. | ||
9 | |||
10 | GNUnet is distributed in the hope that it will be useful, but | ||
11 | WITHOUT ANY WARRANTY; without even the implied warranty of | ||
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
13 | Affero General Public License for more details. | ||
14 | |||
15 | You should have received a copy of the GNU Affero General Public License | ||
16 | along with this program. If not, see <http://www.gnu.org/licenses/>. | ||
17 | |||
18 | SPDX-License-Identifier: AGPL3.0-or-later | ||
19 | */ | ||
20 | |||
21 | /** | ||
22 | * Common buffer management functions. | ||
23 | * | ||
24 | * @author Florian Dold | ||
25 | */ | ||
26 | |||
27 | #ifndef GNUNET_BUFFER_LIB_H | ||
28 | #define GNUNET_BUFFER_LIB_H | ||
29 | |||
30 | /** | ||
31 | * Dynamically growing buffer. Can be used to construct | ||
32 | * strings and other objects with dynamic size. | ||
33 | * | ||
34 | * This structure should, in most cases, be stack-allocated and | ||
35 | * zero-initialized, like: | ||
36 | * | ||
37 | * struct GNUNET_Buffer my_buffer = { 0 }; | ||
38 | */ | ||
39 | struct GNUNET_Buffer | ||
40 | { | ||
41 | /** | ||
42 | * Capacity of the buffer. | ||
43 | */ | ||
44 | size_t capacity; | ||
45 | |||
46 | /** | ||
47 | * Current write position. | ||
48 | */ | ||
49 | size_t position; | ||
50 | |||
51 | /** | ||
52 | * Backing memory. | ||
53 | */ | ||
54 | char *mem; | ||
55 | |||
56 | /** | ||
57 | * Log a warning if the buffer is grown over its initially allocated capacity. | ||
58 | */ | ||
59 | int warn_grow; | ||
60 | }; | ||
61 | |||
62 | |||
63 | /** | ||
64 | * Initialize a buffer with the given capacity. | ||
65 | * | ||
66 | * When a buffer is allocated with this function, a warning is logged | ||
67 | * when the buffer exceeds the initial capacity. | ||
68 | * | ||
69 | * @param buf the buffer to initialize | ||
70 | * @param capacity the capacity (in bytes) to allocate for @a buf | ||
71 | */ | ||
72 | void | ||
73 | GNUNET_buffer_prealloc (struct GNUNET_Buffer *buf, size_t capacity); | ||
74 | |||
75 | |||
76 | /** | ||
77 | * Make sure that at least @a n bytes remaining in the buffer. | ||
78 | * | ||
79 | * @param buf buffer to potentially grow | ||
80 | * @param n number of bytes that should be available to write | ||
81 | */ | ||
82 | void | ||
83 | GNUNET_buffer_ensure_remaining (struct GNUNET_Buffer *buf, size_t n); | ||
84 | |||
85 | |||
86 | /** | ||
87 | * Write bytes to the buffer. | ||
88 | * | ||
89 | * Grows the buffer if necessary. | ||
90 | * | ||
91 | * @param buf buffer to write to | ||
92 | * @param data data to read from | ||
93 | * @param len number of bytes to copy from @a data to @a buf | ||
94 | * | ||
95 | */ | ||
96 | void | ||
97 | GNUNET_buffer_write (struct GNUNET_Buffer *buf, const char *data, size_t len); | ||
98 | |||
99 | |||
100 | /** | ||
101 | * Write a 0-terminated string to a buffer, excluding the 0-terminator. | ||
102 | * | ||
103 | * Grows the buffer if necessary. | ||
104 | * | ||
105 | * @param buf the buffer to write to | ||
106 | * @param str the string to write to @a buf | ||
107 | */ | ||
108 | void | ||
109 | GNUNET_buffer_write_str (struct GNUNET_Buffer *buf, const char *str); | ||
110 | |||
111 | |||
112 | /** | ||
113 | * Write a path component to a buffer, ensuring that | ||
114 | * there is exactly one slash between the previous contents | ||
115 | * of the buffer and the new string. | ||
116 | * | ||
117 | * @param buf buffer to write to | ||
118 | * @param str string containing the new path component | ||
119 | */ | ||
120 | void | ||
121 | GNUNET_buffer_write_path (struct GNUNET_Buffer *buf, const char *str); | ||
122 | |||
123 | |||
124 | /** | ||
125 | * Write a 0-terminated formatted string to a buffer, excluding the | ||
126 | * 0-terminator. | ||
127 | * | ||
128 | * Grows the buffer if necessary. | ||
129 | * | ||
130 | * @param buf the buffer to write to | ||
131 | * @param fmt format string | ||
132 | * @param ... format arguments | ||
133 | */ | ||
134 | void | ||
135 | GNUNET_buffer_write_fstr (struct GNUNET_Buffer *buf, const char *fmt, ...); | ||
136 | |||
137 | |||
138 | /** | ||
139 | * Write a 0-terminated formatted string to a buffer, excluding the | ||
140 | * 0-terminator. | ||
141 | * | ||
142 | * Grows the buffer if necessary. | ||
143 | * | ||
144 | * @param buf the buffer to write to | ||
145 | * @param fmt format string | ||
146 | * @param args format argument list | ||
147 | */ | ||
148 | void | ||
149 | GNUNET_buffer_write_vfstr (struct GNUNET_Buffer *buf, const char *fmt, va_list | ||
150 | args); | ||
151 | |||
152 | |||
153 | /** | ||
154 | * Clear the buffer and return the string it contained. | ||
155 | * The caller is responsible to eventually #GNUNET_free | ||
156 | * the returned string. | ||
157 | * | ||
158 | * The returned string is always 0-terminated. | ||
159 | * | ||
160 | * @param buf the buffer to reap the string from | ||
161 | * @returns the buffer contained in the string | ||
162 | */ | ||
163 | char * | ||
164 | GNUNET_buffer_reap_str (struct GNUNET_Buffer *buf); | ||
165 | |||
166 | |||
167 | /** | ||
168 | * Free the backing memory of the given buffer. | ||
169 | * Does not free the memory of the buffer control structure, | ||
170 | * which is typically stack-allocated. | ||
171 | */ | ||
172 | void | ||
173 | GNUNET_buffer_clear (struct GNUNET_Buffer *buf); | ||
174 | |||
175 | |||
176 | #endif | ||