1 /*
2 * SysDB - src/utils/strbuf.c
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 #include "utils/strbuf.h"
30 #include <assert.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <stdarg.h>
35 #include <string.h>
37 #include <unistd.h>
39 /*
40 * private data structures
41 */
43 struct sdb_strbuf {
44 char *string;
45 size_t size;
46 size_t pos;
47 };
49 /*
50 * private helper functions
51 */
53 static int
54 strbuf_resize(sdb_strbuf_t *strbuf, size_t new_size)
55 {
56 char *tmp;
58 if (new_size <= strbuf->size)
59 return 0;
61 tmp = realloc(strbuf->string, new_size);
62 if (! tmp)
63 return -1;
65 strbuf->string = tmp;
66 strbuf->size = new_size;
67 return 0;
68 } /* strbuf_resize */
70 /*
71 * public API
72 */
74 sdb_strbuf_t *
75 sdb_strbuf_create(size_t size)
76 {
77 sdb_strbuf_t *strbuf;
79 strbuf = calloc(1, sizeof(*strbuf));
80 if (! strbuf)
81 return NULL;
83 strbuf->string = NULL;
84 if (size) {
85 strbuf->string = malloc(size);
86 if (! strbuf->string) {
87 free(strbuf);
88 return NULL;
89 }
91 strbuf->string[0] = '\0';
92 }
94 strbuf->size = size;
95 strbuf->pos = 0;
97 return strbuf;
98 } /* sdb_strbuf_create */
100 void
101 sdb_strbuf_destroy(sdb_strbuf_t *strbuf)
102 {
103 if (! strbuf)
104 return;
106 if (strbuf->string)
107 free(strbuf->string);
108 free(strbuf);
109 } /* sdb_strbuf_destroy */
111 ssize_t
112 sdb_strbuf_vappend(sdb_strbuf_t *strbuf, const char *fmt, va_list ap)
113 {
114 va_list aq;
115 int status;
117 if ((! strbuf) || (! fmt))
118 return -1;
120 assert((strbuf->size == 0) || (strbuf->string[strbuf->pos] == '\0'));
122 if (! strbuf->size) {
123 /* use some arbitrary but somewhat reasonable default */
124 if (strbuf_resize(strbuf, 64))
125 return -1;
126 }
127 /* make sure to reserve space for the nul-byte */
128 else if (strbuf->pos >= strbuf->size - 1)
129 if (strbuf_resize(strbuf, 2 * strbuf->size))
130 return -1;
132 assert(strbuf->size && strbuf->string);
133 assert(strbuf->pos < strbuf->size);
135 /* 'ap' is invalid after calling vsnprintf; thus copy before using it */
136 va_copy(aq, ap);
137 status = vsnprintf(strbuf->string + strbuf->pos,
138 strbuf->size - strbuf->pos, fmt, ap);
140 if (status < 0) {
141 va_end(aq);
142 return status;
143 }
145 /* 'status' does not include nul-byte */
146 if ((size_t)status >= strbuf->size - strbuf->pos - 1) {
147 if (strbuf_resize(strbuf, strbuf->size + (size_t)status)) {
148 va_end(aq);
149 return -1;
150 }
152 /* reset string and try again */
153 strbuf->string[strbuf->pos] = '\0';
154 status = (int)sdb_strbuf_vappend(strbuf, fmt, aq);
155 }
156 else
157 strbuf->pos += (size_t)status;
159 va_end(aq);
160 return (ssize_t)status;
161 } /* sdb_strbuf_vappend */
163 ssize_t
164 sdb_strbuf_append(sdb_strbuf_t *strbuf, const char *fmt, ...)
165 {
166 va_list ap;
167 ssize_t status;
169 va_start(ap, fmt);
170 status = sdb_strbuf_vappend(strbuf, fmt, ap);
171 va_end(ap);
173 return status;
174 } /* sdb_strbuf_append */
176 ssize_t
177 sdb_strbuf_vsprintf(sdb_strbuf_t *strbuf, const char *fmt, va_list ap)
178 {
179 if (! strbuf)
180 return -1;
182 if (strbuf->size) {
183 strbuf->string[0] = '\0';
184 strbuf->pos = 0;
185 }
187 return sdb_strbuf_vappend(strbuf, fmt, ap);
188 } /* sdb_strbuf_vsprintf */
190 ssize_t
191 sdb_strbuf_sprintf(sdb_strbuf_t *strbuf, const char *fmt, ...)
192 {
193 va_list ap;
194 ssize_t status;
196 va_start(ap, fmt);
197 status = sdb_strbuf_vsprintf(strbuf, fmt, ap);
198 va_end(ap);
200 return status;
201 } /* sdb_strbuf_sprintf */
203 ssize_t
204 sdb_strbuf_memappend(sdb_strbuf_t *strbuf, const void *data, size_t n)
205 {
206 if ((! strbuf) || (! data))
207 return -1;
209 assert((strbuf->size == 0) || (strbuf->string[strbuf->pos] == '\0'));
211 if (strbuf->pos + n + 1 >= strbuf->size) {
212 size_t newsize = strbuf->size * 2;
214 if (! newsize)
215 newsize = 64;
216 while (strbuf->pos + n + 1 >= newsize)
217 newsize *= 2;
219 if (strbuf_resize(strbuf, newsize))
220 return -1;
221 }
223 assert(strbuf->size && strbuf->string);
224 assert(strbuf->pos < strbuf->size);
226 memcpy((void *)(strbuf->string + strbuf->pos), data, n);
227 strbuf->pos += n;
228 strbuf->string[strbuf->pos] = '\0';
230 return (ssize_t)n;
231 } /* sdb_strbuf_memappend */
233 ssize_t
234 sdb_strbuf_memcpy(sdb_strbuf_t *strbuf, const void *data, size_t n)
235 {
236 if ((! strbuf) || (! data))
237 return -1;
239 if (strbuf->size) {
240 strbuf->string[0] = '\0';
241 strbuf->pos = 0;
242 }
244 return sdb_strbuf_memappend(strbuf, data, n);
245 } /* sdb_strbuf_memcpy */
247 ssize_t
248 sdb_strbuf_read(sdb_strbuf_t *strbuf, int fd, size_t n)
249 {
250 ssize_t ret;
252 if (! strbuf)
253 return -1;
255 if (strbuf_resize(strbuf, strbuf->pos + n + 1))
256 return -1;
258 ret = read(fd, strbuf->string + strbuf->pos, n);
259 if (ret > 0)
260 strbuf->pos += (size_t)ret;
261 return ret;
262 } /* sdb_strbuf_read */
264 ssize_t
265 sdb_strbuf_chomp(sdb_strbuf_t *strbuf)
266 {
267 ssize_t ret = 0;
269 if (! strbuf)
270 return -1;
272 assert((!strbuf->size) || (strbuf->pos < strbuf->size));
273 assert(strbuf->pos <= strbuf->size);
275 while ((strbuf->pos > 0)
276 && (strbuf->string[strbuf->pos - 1] == '\n')) {
277 --strbuf->pos;
278 strbuf->string[strbuf->pos] = '\0';
279 ++ret;
280 }
282 return ret;
283 } /* sdb_strbuf_chomp */
285 void
286 sdb_strbuf_skip(sdb_strbuf_t *strbuf, size_t offset, size_t n)
287 {
288 char *start;
289 size_t len;
291 if ((! strbuf) || (! n))
292 return;
294 if (offset >= strbuf->pos)
295 return;
297 len = strbuf->pos - offset;
299 if (n >= len) {
300 strbuf->string[offset] = '\0';
301 strbuf->pos = offset;
302 return;
303 }
305 assert(offset + n < strbuf->pos);
306 assert(offset < strbuf->pos);
308 start = strbuf->string + offset;
309 memmove(start, start + n, strbuf->pos - n);
310 strbuf->pos -= n;
311 strbuf->string[strbuf->pos] = '\0';
312 } /* sdb_strbuf_skip */
314 const char *
315 sdb_strbuf_string(sdb_strbuf_t *strbuf)
316 {
317 if (! strbuf)
318 return NULL;
319 if (! strbuf->size)
320 return "";
321 return strbuf->string;
322 } /* sdb_strbuf_string */
324 size_t
325 sdb_strbuf_len(sdb_strbuf_t *strbuf)
326 {
327 if (! strbuf)
328 return 0;
329 return strbuf->pos;
330 } /* sdb_strbuf_string */
332 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */