text: /*
   * This file is part of FFmpeg.
   *
   * FFmpeg is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * FFmpeg is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with FFmpeg; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
   */
  
  #include "config.h"
  #include "file.h"
  #include "internal.h"
  #include "log.h"
  #include "mem.h"
  #include <fcntl.h>
  #include <sys/stat.h>
  #if HAVE_UNISTD_H
  #include <unistd.h>
  #endif
  #if HAVE_IO_H
  #include <io.h>
  #endif
  #if HAVE_MMAP
  #include <sys/mman.h>
  #elif HAVE_MAPVIEWOFFILE
  #include <windows.h>
  #endif
  
  typedef struct {
      const AVClass *class;
      int   log_offset;
      void *log_ctx;
  } FileLogContext;
  
  static const AVClass file_log_ctx_class = {
      "FILE", av_default_item_name, NULL, LIBAVUTIL_VERSION_INT,
      offsetof(FileLogContext, log_offset), offsetof(FileLogContext, log_ctx)
  };
  
  int av_file_map(const char *filename, uint8_t **bufptr, size_t *size,
                  int log_offset, void *log_ctx)
  {
      FileLogContext file_log_ctx = { &file_log_ctx_class, log_offset, log_ctx };
      int err, fd = avpriv_open(filename, O_RDONLY);
      struct stat st;
      av_unused void *ptr;
      off_t off_size;
      char errbuf[128];
      *bufptr = NULL;
  
      if (fd < 0) {
          err = AVERROR(errno);
          av_strerror(err, errbuf, sizeof(errbuf));
          av_log(&file_log_ctx, AV_LOG_ERROR, "Cannot read file '%s': %s\n", filename, errbuf);
          return err;
      }
  
      if (fstat(fd, &st) < 0) {
          err = AVERROR(errno);
          av_strerror(err, errbuf, sizeof(errbuf));
          av_log(&file_log_ctx, AV_LOG_ERROR, "Error occurred in fstat(): %s\n", errbuf);
          close(fd);
          return err;
      }
  
      off_size = st.st_size;
      if (off_size > SIZE_MAX) {
          av_log(&file_log_ctx, AV_LOG_ERROR,
                 "File size for file '%s' is too big\n", filename);
          close(fd);
          return AVERROR(EINVAL);
      }
      *size = off_size;
  
  #if HAVE_MMAP
      ptr = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
      if (ptr == MAP_FAILED) {
          err = AVERROR(errno);
          av_strerror(err, errbuf, sizeof(errbuf));
          av_log(&file_log_ctx, AV_LOG_ERROR, "Error occurred in mmap(): %s\n", errbuf);
          close(fd);
          return err;
      }
      *bufptr = ptr;
  #elif HAVE_MAPVIEWOFFILE
      {
          HANDLE mh, fh = (HANDLE)_get_osfhandle(fd);
  
          mh = CreateFileMapping(fh, NULL, PAGE_READONLY, 0, 0, NULL);
          if (!mh) {
              av_log(&file_log_ctx, AV_LOG_ERROR, "Error occurred in CreateFileMapping()\n");
              close(fd);
              return -1;
          }
  
          ptr = MapViewOfFile(mh, FILE_MAP_READ, 0, 0, *size);
          CloseHandle(mh);
          if (!ptr) {
              av_log(&file_log_ctx, AV_LOG_ERROR, "Error occurred in MapViewOfFile()\n");
              close(fd);
              return -1;
          }
  
          *bufptr = ptr;
      }
  #else
      *bufptr = av_malloc(*size);
      if (!*bufptr) {
          av_log(&file_log_ctx, AV_LOG_ERROR, "Memory allocation error occurred\n");
          close(fd);
          return AVERROR(ENOMEM);
      }
      read(fd, *bufptr, *size);
  #endif
  
      close(fd);
      return 0;
  }
  
  void av_file_unmap(uint8_t *bufptr, size_t size)
  {
  #if HAVE_MMAP
      munmap(bufptr, size);
  #elif HAVE_MAPVIEWOFFILE
      UnmapViewOfFile(bufptr);
  #else
      av_free(bufptr);
  #endif
  }
  
  int av_tempfile(const char *prefix, char **filename, int log_offset, void *log_ctx)
  {
      FileLogContext file_log_ctx = { &file_log_ctx_class, log_offset, log_ctx };
      int fd = -1;
  #if !HAVE_MKSTEMP
      void *ptr= tempnam(NULL, prefix);
      if(!ptr)
          ptr= tempnam(".", prefix);
      *filename = av_strdup(ptr);
  #undef free
      free(ptr);
  #else
      size_t len = strlen(prefix) + 12; /* room for "/tmp/" and "XXXXXX\0" */
      *filename  = av_malloc(len);
  #endif
      /* -----common section-----*/
      if (!*filename) {
          av_log(&file_log_ctx, AV_LOG_ERROR, "ff_tempfile: Cannot allocate file name\n");
          return AVERROR(ENOMEM);
      }
  #if !HAVE_MKSTEMP
  #   ifndef O_BINARY
  #       define O_BINARY 0
  #   endif
  #   ifndef O_EXCL
  #       define O_EXCL 0
  #   endif
      fd = open(*filename, O_RDWR | O_BINARY | O_CREAT | O_EXCL, 0600);
  #else
      snprintf(*filename, len, "/tmp/%sXXXXXX", prefix);
      fd = mkstemp(*filename);
  #ifdef _WIN32
      if (fd < 0) {
          snprintf(*filename, len, "./%sXXXXXX", prefix);
          fd = mkstemp(*filename);
      }
  #endif
  #endif
      /* -----common section-----*/
      if (fd < 0) {
          int err = AVERROR(errno);
          av_log(&file_log_ctx, AV_LOG_ERROR, "ff_tempfile: Cannot open temporary file %s\n", *filename);
          av_freep(filename);
          return err;
      }
      return fd; /* success */
  }
  
  #ifdef TEST
  
  #undef printf
  
  int main(void)
  {
      uint8_t *buf;
      size_t size;
      if (av_file_map("file.c", &buf, &size, 0, NULL) < 0)
          return 1;
  
      buf[0] = 's';
      printf("%s", buf);
      av_file_unmap(buf, size);
      return 0;
  }
  #endif
  
  