2 * Copyright (c) 2012 Nicolas George
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
30 #define av_bprint_room(buf) ((buf)->size - FFMIN((buf)->len, (buf)->size))
31 #define av_bprint_is_allocated(buf) ((buf)->str != (buf)->reserved_internal_buffer)
33 static int av_bprint_alloc(AVBPrint *buf, unsigned room)
35 char *old_str, *new_str;
36 unsigned min_size, new_size;
38 if (buf->size == buf->size_max)
40 if (!av_bprint_is_complete(buf))
41 return AVERROR_INVALIDDATA; /* it is already truncated anyway */
42 min_size = buf->len + 1 + FFMIN(UINT_MAX - buf->len - 1, room);
43 new_size = buf->size > buf->size_max / 2 ? buf->size_max : buf->size * 2;
44 if (new_size < min_size)
45 new_size = FFMIN(buf->size_max, min_size);
46 old_str = av_bprint_is_allocated(buf) ? buf->str : NULL;
47 new_str = av_realloc(old_str, new_size);
49 return AVERROR(ENOMEM);
51 memcpy(new_str, buf->str, buf->len + 1);
57 static void av_bprint_grow(AVBPrint *buf, unsigned extra_len)
59 /* arbitrary margin to avoid small overflows */
60 extra_len = FFMIN(extra_len, UINT_MAX - 5 - buf->len);
61 buf->len += extra_len;
63 buf->str[FFMIN(buf->len, buf->size - 1)] = 0;
66 void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
68 unsigned size_auto = (char *)buf + sizeof(*buf) -
69 buf->reserved_internal_buffer;
73 buf->str = buf->reserved_internal_buffer;
75 buf->size = FFMIN(size_auto, size_max);
76 buf->size_max = size_max;
78 if (size_init > buf->size)
79 av_bprint_alloc(buf, size_init - 1);
82 void av_bprint_init_for_buffer(AVBPrint *buf, char *buffer, unsigned size)
91 void av_bprintf(AVBPrint *buf, const char *fmt, ...)
99 room = av_bprint_room(buf);
100 dst = room ? buf->str + buf->len : NULL;
102 extra_len = vsnprintf(dst, room, fmt, vl);
106 if (extra_len < room)
108 if (av_bprint_alloc(buf, extra_len))
111 av_bprint_grow(buf, extra_len);
114 void av_bprint_chars(AVBPrint *buf, char c, unsigned n)
116 unsigned room, real_n;
119 room = av_bprint_room(buf);
122 if (av_bprint_alloc(buf, n))
126 real_n = FFMIN(n, room - 1);
127 memset(buf->str + buf->len, c, real_n);
129 av_bprint_grow(buf, n);
132 void av_bprint_clear(AVBPrint *buf)
140 int av_bprint_finalize(AVBPrint *buf, char **ret_str)
142 unsigned real_size = FFMIN(buf->len + 1, buf->size);
147 if (av_bprint_is_allocated(buf)) {
148 str = av_realloc(buf->str, real_size);
153 str = av_malloc(real_size);
155 memcpy(str, buf->str, real_size);
157 ret = AVERROR(ENOMEM);
161 if (av_bprint_is_allocated(buf))
164 buf->size = real_size;
172 static void bprint_pascal(AVBPrint *b, unsigned size)
177 av_assert0(size < FF_ARRAY_ELEMS(p));
180 av_bprintf(b, "%8d\n", 1);
181 for (i = 1; i <= size; i++) {
183 for (j = i - 1; j > 0; j--)
184 p[j] = p[j] + p[j - 1];
185 for (j = 0; j <= i; j++)
186 av_bprintf(b, "%8d", p[j]);
196 av_bprint_init(&b, 0, -1);
197 bprint_pascal(&b, 5);
198 printf("Short text in unlimited buffer: %u/%u\n", (unsigned)strlen(b.str), b.len);
199 printf("%s\n", b.str);
200 av_bprint_finalize(&b, NULL);
202 av_bprint_init(&b, 0, -1);
203 bprint_pascal(&b, 25);
204 printf("Long text in unlimited buffer: %u/%u\n", (unsigned)strlen(b.str), b.len);
205 av_bprint_finalize(&b, NULL);
207 av_bprint_init(&b, 0, 2048);
208 bprint_pascal(&b, 25);
209 printf("Long text in limited buffer: %u/%u\n", (unsigned)strlen(b.str), b.len);
210 av_bprint_finalize(&b, NULL);
212 av_bprint_init(&b, 0, 1);
213 bprint_pascal(&b, 5);
214 printf("Short text in automatic buffer: %u/%u\n", (unsigned)strlen(b.str), b.len);
216 av_bprint_init(&b, 0, 1);
217 bprint_pascal(&b, 25);
218 printf("Long text in automatic buffer: %u/%u\n", (unsigned)strlen(b.str)/8*8, b.len);
219 /* Note that the size of the automatic buffer is arch-dependant. */
221 av_bprint_init(&b, 0, 0);
222 bprint_pascal(&b, 25);
223 printf("Long text count only buffer: %u/%u\n", (unsigned)strlen(b.str), b.len);
225 av_bprint_init_for_buffer(&b, buf, sizeof(buf));
226 bprint_pascal(&b, 25);
227 printf("Long text count only buffer: %u/%u\n", (unsigned)strlen(buf), b.len);