1 /*
2 * SysDB - src/include/utils/strbuf.h
3 * Copyright (C) 2012 Sebastian 'tokkee' Harl <sh@tokkee.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
28 /*
29 * SysDB string buffer:
30 * This is an implementation of an automatically growing string. Whenever
31 * writing to the buffer, it will be ensured that enough space is allocated to
32 * store all of the string.
33 */
35 #ifndef SDB_UTILS_STRBUF_H
36 #define SDB_UTILS_STRBUF_H 1
38 #include <stdarg.h>
39 #include <stdio.h>
40 #include <unistd.h>
42 #ifdef __cplusplus
43 extern "C" {
44 #endif
46 typedef struct sdb_strbuf sdb_strbuf_t;
48 /*
49 * SDB_STRBUF_STR:
50 * Return a tuple of a character array and its length representing the content
51 * of the string buffer.
52 */
53 #define SDB_STRBUF_STR(buf) sdb_strbuf_string(buf), sdb_strbuf_len(buf)
55 /*
56 * sdb_strbuf_create, sdb_strbuf_destroy:
57 * Allocate / deallocate string buffer objects. The initial size of a newly
58 * created string buffer is determined by the 'size' argument of the create
59 * function.
60 *
61 * sdb_strbuf_create returns:
62 * - the new string buffer object on success
63 * - NULL else
64 */
65 sdb_strbuf_t *
66 sdb_strbuf_create(size_t size);
68 void
69 sdb_strbuf_destroy(sdb_strbuf_t *strbuf);
71 /*
72 * sdb_strbuf_vappend, sdb_strbuf_append:
73 * Append to an existing string buffer. The new text will be added at the end
74 * of the current content of the buffer.
75 *
76 * The 'fmt' and all following arguments are identical to those passed to the
77 * sprintf / vsprintf functions.
78 *
79 * Returns:
80 * - the number of bytes written
81 * - a negative value on error
82 */
83 ssize_t
84 sdb_strbuf_vappend(sdb_strbuf_t *strbuf, const char *fmt, va_list ap)
85 __attribute__((format(printf, 2, 0)));
86 ssize_t
87 sdb_strbuf_append(sdb_strbuf_t *strbuf, const char *fmt, ...)
88 __attribute__((format(printf, 2, 3)));
90 /*
91 * sdb_strbuf_vsprintf, sdb_strbuf_sprintf:
92 * Write to an existing string buffer, overwriting any previous content.
93 *
94 * The 'fmt' and all following arguments are identical to those passed to the
95 * sprintf / vsprintf functions.
96 *
97 * Returns:
98 * - the number of bytes written
99 * - a negative value on error
100 */
101 ssize_t
102 sdb_strbuf_vsprintf(sdb_strbuf_t *strbuf, const char *fmt, va_list ap)
103 __attribute__((format(printf, 2, 0)));
104 ssize_t
105 sdb_strbuf_sprintf(sdb_strbuf_t *strbuf, const char *fmt, ...)
106 __attribute__((format(printf, 2, 3)));
108 /*
109 * sdb_strbuf_memcpy, sdb_strbuf_memappend:
110 * Copy or a append a memory area to the buffer. These functions do not
111 * interpret any information in the data pointer (including \0 bytes).
112 *
113 * These functions may be used to handle arbitrary byte arrays. Mixing these
114 * function calls with any of the printf-style function works fine but the
115 * entire buffer content should then be treated as arbitrary bytes.
116 *
117 * Returns:
118 * - the number of bytes written
119 * - a negative value on error
120 */
121 ssize_t
122 sdb_strbuf_memcpy(sdb_strbuf_t *strbuf, const void *data, size_t n);
123 ssize_t
124 sdb_strbuf_memappend(sdb_strbuf_t *strbuf, const void *data, size_t n);
126 /*
127 * sdb_strbuf_read:
128 * Read from an open file-descriptor and append the data to the buffer. The
129 * function does not handle *any* read errors. This allows for more
130 * flexibility for the caller regarding the handling of EAGAIN or EWOULDBLOCK.
131 *
132 * Returns:
133 * - the number of bytes read (zero on EOF)
134 * - a negative value on error
135 */
136 ssize_t
137 sdb_strbuf_read(sdb_strbuf_t *strbuf, int fd, size_t n);
139 /*
140 * sdb_strbuf_chomp:
141 * Remove all consecutive newline characters from the end of the string buffer
142 * content.
143 *
144 * Returns:
145 * - the number of bytes removed
146 * - a negative value on error
147 */
148 ssize_t
149 sdb_strbuf_chomp(sdb_strbuf_t *strbuf);
151 /*
152 * sdb_strbuf_skip:
153 * Removes 'n' bytes from the buffer starting at offset 'offset'.
154 */
155 void
156 sdb_strbuf_skip(sdb_strbuf_t *strbuf, size_t offset, size_t n);
158 /*
159 * sdb_strbuf_clear:
160 * Clear the buffer but do not deallocate memory.
161 */
162 void
163 sdb_strbuf_clear(sdb_strbuf_t *strbuf);
165 /*
166 * sdb_strbuf_string:
167 * Returns the content of the string buffer. The caller may not modify the
168 * string.
169 */
170 const char *
171 sdb_strbuf_string(sdb_strbuf_t *strbuf);
173 /*
174 * sdb_strbuf_len:
175 * Returns the length of the string buffer's content.
176 */
177 size_t
178 sdb_strbuf_len(sdb_strbuf_t *strbuf);
180 /*
181 * sdb_strbuf_cap:
182 * Returns the current capacity of the string buffer. It describes the max
183 * length of the buffer's content (including terminating nul byte) that may be
184 * stored in the buffer without resizing it.
185 */
186 size_t
187 sdb_strbuf_cap(sdb_strbuf_t *strbuf);
189 #ifdef __cplusplus
190 } /* extern "C" */
191 #endif
193 #endif /* ! SDB_UTILS_STRBUF_H */
195 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */