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405 lines
12 KiB
405 lines
12 KiB
/* |
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* Copyright (c) 2012 Nicolas George |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#include <stdarg.h> |
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#include <stdio.h> |
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#include <string.h> |
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#include <time.h> |
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#include "avassert.h" |
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#include "avstring.h" |
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#include "bprint.h" |
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#include "common.h" |
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#include "compat/va_copy.h" |
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#include "error.h" |
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#include "mem.h" |
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#if HAVE_IO_H |
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#include <io.h> |
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#endif |
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#if HAVE_UNISTD_H |
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#include <unistd.h> |
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#endif |
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#define av_bprint_room(buf) ((buf)->size - FFMIN((buf)->len, (buf)->size)) |
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#define av_bprint_is_allocated(buf) ((buf)->str != (buf)->reserved_internal_buffer) |
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static int av_bprint_alloc(AVBPrint *buf, unsigned room) |
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{ |
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char *old_str, *new_str; |
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unsigned min_size, new_size; |
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if (buf->size == buf->size_max) |
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return AVERROR(EIO); |
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if (!av_bprint_is_complete(buf)) |
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return AVERROR_INVALIDDATA; /* it is already truncated anyway */ |
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min_size = buf->len + 1 + FFMIN(UINT_MAX - buf->len - 1, room); |
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new_size = buf->size > buf->size_max / 2 ? buf->size_max : buf->size * 2; |
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if (new_size < min_size) |
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new_size = FFMIN(buf->size_max, min_size); |
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old_str = av_bprint_is_allocated(buf) ? buf->str : NULL; |
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new_str = av_realloc(old_str, new_size); |
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if (!new_str) |
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return AVERROR(ENOMEM); |
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if (!old_str) |
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memcpy(new_str, buf->str, buf->len + 1); |
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buf->str = new_str; |
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buf->size = new_size; |
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return 0; |
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} |
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static void av_bprint_grow(AVBPrint *buf, unsigned extra_len) |
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{ |
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/* arbitrary margin to avoid small overflows */ |
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extra_len = FFMIN(extra_len, UINT_MAX - 5 - buf->len); |
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buf->len += extra_len; |
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if (buf->size) |
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buf->str[FFMIN(buf->len, buf->size - 1)] = 0; |
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} |
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void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max) |
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{ |
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unsigned size_auto = (char *)buf + sizeof(*buf) - |
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buf->reserved_internal_buffer; |
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if (size_max == 1) |
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size_max = size_auto; |
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buf->str = buf->reserved_internal_buffer; |
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buf->len = 0; |
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buf->size = FFMIN(size_auto, size_max); |
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buf->size_max = size_max; |
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*buf->str = 0; |
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if (size_init > buf->size) |
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av_bprint_alloc(buf, size_init - 1); |
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} |
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void av_bprint_init_for_buffer(AVBPrint *buf, char *buffer, unsigned size) |
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{ |
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buf->str = buffer; |
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buf->len = 0; |
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buf->size = size; |
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buf->size_max = size; |
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*buf->str = 0; |
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} |
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void av_bprintf(AVBPrint *buf, const char *fmt, ...) |
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{ |
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unsigned room; |
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char *dst; |
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va_list vl; |
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int extra_len; |
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while (1) { |
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room = av_bprint_room(buf); |
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dst = room ? buf->str + buf->len : NULL; |
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va_start(vl, fmt); |
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extra_len = vsnprintf(dst, room, fmt, vl); |
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va_end(vl); |
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if (extra_len <= 0) |
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return; |
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if (extra_len < room) |
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break; |
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if (av_bprint_alloc(buf, extra_len)) |
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break; |
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} |
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av_bprint_grow(buf, extra_len); |
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} |
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void av_vbprintf(AVBPrint *buf, const char *fmt, va_list vl_arg) |
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{ |
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unsigned room; |
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char *dst; |
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int extra_len; |
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va_list vl; |
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while (1) { |
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room = av_bprint_room(buf); |
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dst = room ? buf->str + buf->len : NULL; |
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va_copy(vl, vl_arg); |
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extra_len = vsnprintf(dst, room, fmt, vl); |
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va_end(vl); |
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if (extra_len <= 0) |
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return; |
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if (extra_len < room) |
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break; |
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if (av_bprint_alloc(buf, extra_len)) |
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break; |
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} |
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av_bprint_grow(buf, extra_len); |
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} |
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void av_bprint_chars(AVBPrint *buf, char c, unsigned n) |
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{ |
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unsigned room, real_n; |
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while (1) { |
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room = av_bprint_room(buf); |
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if (n < room) |
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break; |
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if (av_bprint_alloc(buf, n)) |
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break; |
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} |
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if (room) { |
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real_n = FFMIN(n, room - 1); |
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memset(buf->str + buf->len, c, real_n); |
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} |
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av_bprint_grow(buf, n); |
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} |
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void av_bprint_append_data(AVBPrint *buf, const char *data, unsigned size) |
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{ |
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unsigned room, real_n; |
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while (1) { |
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room = av_bprint_room(buf); |
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if (size < room) |
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break; |
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if (av_bprint_alloc(buf, size)) |
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break; |
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} |
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if (room) { |
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real_n = FFMIN(size, room - 1); |
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memcpy(buf->str + buf->len, data, real_n); |
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} |
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av_bprint_grow(buf, size); |
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} |
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void av_bprint_strftime(AVBPrint *buf, const char *fmt, const struct tm *tm) |
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{ |
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unsigned room; |
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size_t l; |
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if (!*fmt) |
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return; |
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while (1) { |
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room = av_bprint_room(buf); |
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if (room && (l = strftime(buf->str + buf->len, room, fmt, tm))) |
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break; |
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/* strftime does not tell us how much room it would need: let us |
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retry with twice as much until the buffer is large enough */ |
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room = !room ? strlen(fmt) + 1 : |
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room <= INT_MAX / 2 ? room * 2 : INT_MAX; |
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if (av_bprint_alloc(buf, room)) { |
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/* impossible to grow, try to manage something useful anyway */ |
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room = av_bprint_room(buf); |
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if (room < 1024) { |
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/* if strftime fails because the buffer has (almost) reached |
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its maximum size, let us try in a local buffer; 1k should |
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be enough to format any real date+time string */ |
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char buf2[1024]; |
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if ((l = strftime(buf2, sizeof(buf2), fmt, tm))) { |
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av_bprintf(buf, "%s", buf2); |
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return; |
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} |
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} |
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if (room) { |
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/* if anything else failed and the buffer is not already |
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truncated, let us add a stock string and force truncation */ |
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static const char txt[] = "[truncated strftime output]"; |
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memset(buf->str + buf->len, '!', room); |
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memcpy(buf->str + buf->len, txt, FFMIN(sizeof(txt) - 1, room)); |
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av_bprint_grow(buf, room); /* force truncation */ |
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} |
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return; |
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} |
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} |
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av_bprint_grow(buf, l); |
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} |
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void av_bprint_get_buffer(AVBPrint *buf, unsigned size, |
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unsigned char **mem, unsigned *actual_size) |
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{ |
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if (size > av_bprint_room(buf)) |
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av_bprint_alloc(buf, size); |
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*actual_size = av_bprint_room(buf); |
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*mem = *actual_size ? buf->str + buf->len : NULL; |
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} |
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void av_bprint_clear(AVBPrint *buf) |
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{ |
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if (buf->len) { |
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*buf->str = 0; |
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buf->len = 0; |
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} |
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} |
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int av_bprint_finalize(AVBPrint *buf, char **ret_str) |
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{ |
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unsigned real_size = FFMIN(buf->len + 1, buf->size); |
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char *str; |
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int ret = 0; |
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if (ret_str) { |
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if (av_bprint_is_allocated(buf)) { |
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str = av_realloc(buf->str, real_size); |
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if (!str) |
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str = buf->str; |
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buf->str = NULL; |
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} else { |
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str = av_malloc(real_size); |
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if (str) |
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memcpy(str, buf->str, real_size); |
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else |
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ret = AVERROR(ENOMEM); |
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} |
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*ret_str = str; |
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} else { |
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if (av_bprint_is_allocated(buf)) |
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av_freep(&buf->str); |
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} |
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buf->size = real_size; |
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return ret; |
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} |
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#define WHITESPACES " \n\t" |
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void av_bprint_escape(AVBPrint *dstbuf, const char *src, const char *special_chars, |
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enum AVEscapeMode mode, int flags) |
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{ |
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const char *src0 = src; |
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if (mode == AV_ESCAPE_MODE_AUTO) |
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mode = AV_ESCAPE_MODE_BACKSLASH; /* TODO: implement a heuristic */ |
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switch (mode) { |
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case AV_ESCAPE_MODE_QUOTE: |
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/* enclose the string between '' */ |
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av_bprint_chars(dstbuf, '\'', 1); |
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for (; *src; src++) { |
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if (*src == '\'') |
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av_bprintf(dstbuf, "'\\''"); |
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else |
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av_bprint_chars(dstbuf, *src, 1); |
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} |
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av_bprint_chars(dstbuf, '\'', 1); |
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break; |
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/* case AV_ESCAPE_MODE_BACKSLASH or unknown mode */ |
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default: |
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/* \-escape characters */ |
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for (; *src; src++) { |
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int is_first_last = src == src0 || !*(src+1); |
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int is_ws = !!strchr(WHITESPACES, *src); |
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int is_strictly_special = special_chars && strchr(special_chars, *src); |
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int is_special = |
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is_strictly_special || strchr("'\\", *src) || |
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(is_ws && (flags & AV_ESCAPE_FLAG_WHITESPACE)); |
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if (is_strictly_special || |
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(!(flags & AV_ESCAPE_FLAG_STRICT) && |
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(is_special || (is_ws && is_first_last)))) |
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av_bprint_chars(dstbuf, '\\', 1); |
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av_bprint_chars(dstbuf, *src, 1); |
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} |
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break; |
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} |
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} |
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int av_bprint_fd_contents(AVBPrint *pb, int fd) |
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{ |
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int ret; |
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char buf[1024]; |
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while (1) { |
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ret = read(fd, buf, sizeof(buf)); |
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if (!ret) |
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return 0; |
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else if (ret < 0) |
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return AVERROR(errno); |
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av_bprint_append_data(pb, buf, ret); |
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if (!av_bprint_is_complete(pb)) |
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return AVERROR(ENOMEM); |
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} |
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} |
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#ifdef TEST |
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#undef printf |
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static void bprint_pascal(AVBPrint *b, unsigned size) |
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{ |
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unsigned i, j; |
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unsigned p[42]; |
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av_assert0(size < FF_ARRAY_ELEMS(p)); |
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p[0] = 1; |
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av_bprintf(b, "%8d\n", 1); |
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for (i = 1; i <= size; i++) { |
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p[i] = 1; |
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for (j = i - 1; j > 0; j--) |
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p[j] = p[j] + p[j - 1]; |
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for (j = 0; j <= i; j++) |
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av_bprintf(b, "%8d", p[j]); |
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av_bprintf(b, "\n"); |
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} |
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} |
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int main(void) |
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{ |
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AVBPrint b; |
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char buf[256]; |
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struct tm testtime = { .tm_year = 100, .tm_mon = 11, .tm_mday = 20 }; |
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av_bprint_init(&b, 0, -1); |
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bprint_pascal(&b, 5); |
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printf("Short text in unlimited buffer: %u/%u\n", (unsigned)strlen(b.str), b.len); |
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printf("%s\n", b.str); |
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av_bprint_finalize(&b, NULL); |
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av_bprint_init(&b, 0, -1); |
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bprint_pascal(&b, 25); |
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printf("Long text in unlimited buffer: %u/%u\n", (unsigned)strlen(b.str), b.len); |
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av_bprint_finalize(&b, NULL); |
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av_bprint_init(&b, 0, 2048); |
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bprint_pascal(&b, 25); |
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printf("Long text in limited buffer: %u/%u\n", (unsigned)strlen(b.str), b.len); |
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av_bprint_finalize(&b, NULL); |
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av_bprint_init(&b, 0, 1); |
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bprint_pascal(&b, 5); |
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printf("Short text in automatic buffer: %u/%u\n", (unsigned)strlen(b.str), b.len); |
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av_bprint_init(&b, 0, 1); |
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bprint_pascal(&b, 25); |
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printf("Long text in automatic buffer: %u/%u\n", (unsigned)strlen(b.str)/8*8, b.len); |
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/* Note that the size of the automatic buffer is arch-dependent. */ |
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av_bprint_init(&b, 0, 0); |
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bprint_pascal(&b, 25); |
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printf("Long text count only buffer: %u/%u\n", (unsigned)strlen(b.str), b.len); |
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av_bprint_init_for_buffer(&b, buf, sizeof(buf)); |
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bprint_pascal(&b, 25); |
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printf("Long text count only buffer: %u/%u\n", (unsigned)strlen(buf), b.len); |
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av_bprint_init(&b, 0, -1); |
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av_bprint_strftime(&b, "%Y-%m-%d", &testtime); |
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printf("strftime full: %u/%u \"%s\"\n", (unsigned)strlen(buf), b.len, b.str); |
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av_bprint_finalize(&b, NULL); |
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av_bprint_init(&b, 0, 8); |
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av_bprint_strftime(&b, "%Y-%m-%d", &testtime); |
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printf("strftime truncated: %u/%u \"%s\"\n", (unsigned)strlen(buf), b.len, b.str); |
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return 0; |
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} |
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#endif
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