C++ (Cpp) libretrodb_read_metadata示例

示例#1

文件： libretrodb.c 项目： CrypticGator/RetroArch

int libretrodb_open(const char *path, libretrodb_t *db)
{
   libretrodb_header_t header;
   libretrodb_metadata_t md;
   int rv;
   RFILE *fd = filestream_open(path, RFILE_MODE_READ, -1);

   if (!fd)
      return -errno;

   strlcpy(db->path, path, sizeof(db->path));
   db->root = filestream_seek(fd, 0, SEEK_CUR);

   if ((rv = filestream_read(fd, &header, sizeof(header))) == -1)
   {
      rv = -errno;
      goto error;
   }

   if (strncmp(header.magic_number, MAGIC_NUMBER, sizeof(MAGIC_NUMBER)) != 0)
   {
      rv = -EINVAL;
      goto error;
   }

   header.metadata_offset = swap_if_little64(header.metadata_offset);
   filestream_seek(fd, (ssize_t)header.metadata_offset, SEEK_SET);

   if (libretrodb_read_metadata(fd, &md) < 0)
   {
      rv = -EINVAL;
      goto error;
   }

   db->count = md.count;
   db->first_index_offset = filestream_seek(fd, 0, SEEK_CUR);
   db->fd = fd;
   return 0;

error:
   if (fd)
      filestream_close(fd);
   return rv;
}

示例#2

文件： libretrodb.c 项目： Shamim1977/RetroArch

int libretrodb_open(const char *path, libretrodb_t *db)
{
   libretrodb_header_t header;
   libretrodb_metadata_t md;
   int rv;
   int fd = open(path, O_RDWR);

   if (fd == -1)
      return -errno;

   strcpy(db->path, path);
   db->root = lseek(fd, 0, SEEK_CUR);

   if ((rv = read(fd, &header, sizeof(header))) == -1)
   {
      rv = -errno;
      goto error;
   }

   if (strncmp(header.magic_number, MAGIC_NUMBER, sizeof(MAGIC_NUMBER)) != 0)
   {
      rv = -EINVAL;
      goto error;
   }

   header.metadata_offset = betoht64(header.metadata_offset);
   lseek(fd, header.metadata_offset, SEEK_SET);

   if (libretrodb_read_metadata(fd, &md) < 0)
   {
      rv = -EINVAL;
      goto error;
   }

   db->count = md.count;
   db->first_index_offset = lseek(fd, 0, SEEK_CUR);
   db->fd = fd;
   return 0;
error:
   close(fd);
   return rv;
}