libavutil/file.h

   1 /*
   2  * This file is part of FFmpeg.
   3  *
   4  * FFmpeg is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * FFmpeg is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with FFmpeg; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19 #ifndef AVUTIL_FILE_H
  20 #define AVUTIL_FILE_H
  21
  22 #include <stddef.h>
  23 #include <stdint.h>
  24
  25 #include "attributes.h"
  26
  27 /**
  28  * @file
  29  * Misc file utilities.
  30  */
  31
  32 /**
  33  * Read the file with name filename, and put its content in a newly
  34  * allocated buffer or map it with mmap() when available.
  35  * In case of success set *bufptr to the read or mmapped buffer, and
  36  * *size to the size in bytes of the buffer in *bufptr.
  37  * Unlike mmap this function succeeds with zero sized files, in this
  38  * case *bufptr will be set to NULL and *size will be set to 0.
  39  * The returned buffer must be released with av_file_unmap().
  40  *
  41  * @param log_offset loglevel offset used for logging
  42  * @param log_ctx context used for logging
  43  * @return a non negative number in case of success, a negative value
  44  * corresponding to an AVERROR error code in case of failure
  45  */
  46 av_warn_unused_result
  47 int av_file_map(const char *filename, uint8_t **bufptr, size_t *size,
  48                 int log_offset, void *log_ctx);
  49
  50 /**
  51  * Unmap or free the buffer bufptr created by av_file_map().
  52  *
  53  * @param size size in bytes of bufptr, must be the same as returned
  54  * by av_file_map()
  55  */
  56 void av_file_unmap(uint8_t *bufptr, size_t size);
  57
  58 /**
  59  * Wrapper to work around the lack of mkstemp() on mingw.
  60  * Also, tries to create file in /tmp first, if possible.
  61  * *prefix can be a character constant; *filename will be allocated internally.
  62  * @return file descriptor of opened file (or negative value corresponding to an
  63  * AVERROR code on error)
  64  * and opened file name in **filename.
  65  * @note On very old libcs it is necessary to set a secure umask before
  66  *       calling this, av_tempfile() can't call umask itself as it is used in
  67  *       libraries and could interfere with the calling application.
  68  * @deprecated as fd numbers cannot be passed saftely between libs on some platforms
  69  */
  70 int av_tempfile(const char *prefix, char **filename, int log_offset, void *log_ctx);
  71
  72 #endif /* AVUTIL_FILE_H */