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-rw-r--r--strbuf.c110
1 files changed, 29 insertions, 81 deletions
diff --git a/strbuf.c b/strbuf.c
index ed13367..2dc30be 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -26,6 +26,7 @@
26#include <stdlib.h> 26#include <stdlib.h>
27#include <stdarg.h> 27#include <stdarg.h>
28#include <string.h> 28#include <string.h>
29#include <stdint.h>
29 30
30#include "strbuf.h" 31#include "strbuf.h"
31 32
@@ -38,22 +39,22 @@ static void die(const char *fmt, ...)
38 va_end(arg); 39 va_end(arg);
39 fprintf(stderr, "\n"); 40 fprintf(stderr, "\n");
40 41
41 exit(-1); 42 abort();
42} 43}
43 44
44void strbuf_init(strbuf_t *s, int len) 45void strbuf_init(strbuf_t *s, size_t len)
45{ 46{
46 int size; 47 size_t size;
47 48
48 if (len <= 0) 49 if (!len)
49 size = STRBUF_DEFAULT_SIZE; 50 size = STRBUF_DEFAULT_SIZE;
50 else 51 else
51 size = len + 1; /* \0 terminator */ 52 size = len + 1;
52 53 if (size < len)
54 die("Overflow, len: %zu", len);
53 s->buf = NULL; 55 s->buf = NULL;
54 s->size = size; 56 s->size = size;
55 s->length = 0; 57 s->length = 0;
56 s->increment = STRBUF_DEFAULT_INCREMENT;
57 s->dynamic = 0; 58 s->dynamic = 0;
58 s->reallocs = 0; 59 s->reallocs = 0;
59 s->debug = 0; 60 s->debug = 0;
@@ -65,7 +66,7 @@ void strbuf_init(strbuf_t *s, int len)
65 strbuf_ensure_null(s); 66 strbuf_ensure_null(s);
66} 67}
67 68
68strbuf_t *strbuf_new(int len) 69strbuf_t *strbuf_new(size_t len)
69{ 70{
70 strbuf_t *s; 71 strbuf_t *s;
71 72
@@ -81,20 +82,10 @@ strbuf_t *strbuf_new(int len)
81 return s; 82 return s;
82} 83}
83 84
84void strbuf_set_increment(strbuf_t *s, int increment)
85{
86 /* Increment > 0: Linear buffer growth rate
87 * Increment < -1: Exponential buffer growth rate */
88 if (increment == 0 || increment == -1)
89 die("BUG: Invalid string increment");
90
91 s->increment = increment;
92}
93
94static inline void debug_stats(strbuf_t *s) 85static inline void debug_stats(strbuf_t *s)
95{ 86{
96 if (s->debug) { 87 if (s->debug) {
97 fprintf(stderr, "strbuf(%lx) reallocs: %d, length: %d, size: %d\n", 88 fprintf(stderr, "strbuf(%lx) reallocs: %d, length: %zd, size: %zd\n",
98 (long)s, s->reallocs, s->length, s->size); 89 (long)s, s->reallocs, s->length, s->size);
99 } 90 }
100} 91}
@@ -113,7 +104,7 @@ void strbuf_free(strbuf_t *s)
113 free(s); 104 free(s);
114} 105}
115 106
116char *strbuf_free_to_string(strbuf_t *s, int *len) 107char *strbuf_free_to_string(strbuf_t *s, size_t *len)
117{ 108{
118 char *buf; 109 char *buf;
119 110
@@ -131,57 +122,63 @@ char *strbuf_free_to_string(strbuf_t *s, int *len)
131 return buf; 122 return buf;
132} 123}
133 124
134static int calculate_new_size(strbuf_t *s, int len) 125static size_t calculate_new_size(strbuf_t *s, size_t len)
135{ 126{
136 int reqsize, newsize; 127 size_t reqsize, newsize;
137 128
138 if (len <= 0) 129 if (len <= 0)
139 die("BUG: Invalid strbuf length requested"); 130 die("BUG: Invalid strbuf length requested");
140 131
141 /* Ensure there is room for optional NULL termination */ 132 /* Ensure there is room for optional NULL termination */
142 reqsize = len + 1; 133 reqsize = len + 1;
134 if (reqsize < len)
135 die("Overflow, len: %zu", len);
143 136
144 /* If the user has requested to shrink the buffer, do it exactly */ 137 /* If the user has requested to shrink the buffer, do it exactly */
145 if (s->size > reqsize) 138 if (s->size > reqsize)
146 return reqsize; 139 return reqsize;
147 140
148 newsize = s->size; 141 newsize = s->size;
149 if (s->increment < 0) { 142 if (reqsize >= SIZE_MAX / 2) {
143 newsize = reqsize;
144 } else {
150 /* Exponential sizing */ 145 /* Exponential sizing */
151 while (newsize < reqsize) 146 while (newsize < reqsize)
152 newsize *= -s->increment; 147 newsize *= 2;
153 } else if (s->increment != 0) {
154 /* Linear sizing */
155 newsize = ((newsize + s->increment - 1) / s->increment) * s->increment;
156 } 148 }
157 149
150 if (newsize < reqsize)
151 die("BUG: strbuf length would overflow, len: %zu", len);
152
153
158 return newsize; 154 return newsize;
159} 155}
160 156
161 157
162/* Ensure strbuf can handle a string length bytes long (ignoring NULL 158/* Ensure strbuf can handle a string length bytes long (ignoring NULL
163 * optional termination). */ 159 * optional termination). */
164void strbuf_resize(strbuf_t *s, int len) 160void strbuf_resize(strbuf_t *s, size_t len)
165{ 161{
166 int newsize; 162 size_t newsize;
167 163
168 newsize = calculate_new_size(s, len); 164 newsize = calculate_new_size(s, len);
169 165
170 if (s->debug > 1) { 166 if (s->debug > 1) {
171 fprintf(stderr, "strbuf(%lx) resize: %d => %d\n", 167 fprintf(stderr, "strbuf(%lx) resize: %zd => %zd\n",
172 (long)s, s->size, newsize); 168 (long)s, s->size, newsize);
173 } 169 }
174 170
175 s->size = newsize; 171 s->size = newsize;
176 s->buf = realloc(s->buf, s->size); 172 s->buf = realloc(s->buf, s->size);
177 if (!s->buf) 173 if (!s->buf)
178 die("Out of memory"); 174 die("Out of memory, len: %zu", len);
179 s->reallocs++; 175 s->reallocs++;
180} 176}
181 177
182void strbuf_append_string(strbuf_t *s, const char *str) 178void strbuf_append_string(strbuf_t *s, const char *str)
183{ 179{
184 int space, i; 180 int i;
181 size_t space;
185 182
186 space = strbuf_empty_length(s); 183 space = strbuf_empty_length(s);
187 184
@@ -197,55 +194,6 @@ void strbuf_append_string(strbuf_t *s, const char *str)
197 } 194 }
198} 195}
199 196
200/* strbuf_append_fmt() should only be used when an upper bound
201 * is known for the output string. */
202void strbuf_append_fmt(strbuf_t *s, int len, const char *fmt, ...)
203{
204 va_list arg;
205 int fmt_len;
206
207 strbuf_ensure_empty_length(s, len);
208
209 va_start(arg, fmt);
210 fmt_len = vsnprintf(s->buf + s->length, len, fmt, arg);
211 va_end(arg);
212
213 if (fmt_len < 0)
214 die("BUG: Unable to convert number"); /* This should never happen.. */
215
216 s->length += fmt_len;
217}
218
219/* strbuf_append_fmt_retry() can be used when the there is no known
220 * upper bound for the output string. */
221void strbuf_append_fmt_retry(strbuf_t *s, const char *fmt, ...)
222{
223 va_list arg;
224 int fmt_len, try;
225 int empty_len;
226
227 /* If the first attempt to append fails, resize the buffer appropriately
228 * and try again */
229 for (try = 0; ; try++) {
230 va_start(arg, fmt);
231 /* Append the new formatted string */
232 /* fmt_len is the length of the string required, excluding the
233 * trailing NULL */
234 empty_len = strbuf_empty_length(s);
235 /* Add 1 since there is also space to store the terminating NULL. */
236 fmt_len = vsnprintf(s->buf + s->length, empty_len + 1, fmt, arg);
237 va_end(arg);
238
239 if (fmt_len <= empty_len)
240 break; /* SUCCESS */
241 if (try > 0)
242 die("BUG: length of formatted string changed");
243
244 strbuf_resize(s, s->length + fmt_len);
245 }
246
247 s->length += fmt_len;
248}
249 197
250/* vi:ai et sw=4 ts=4: 198/* vi:ai et sw=4 ts=4:
251 */ 199 */