Function _fdt_slot_expand

components/dfs/dfs_v2/src/dfs.c:57–92

* @brief Expand the file descriptor table to accommodate a specified file descriptor * * This function ensures that the file descriptor table in the given `dfs_fdtable` structure * has sufficient capacity to include the specified file descriptor `fd`. If the table * needs to be expanded, it reallocates memory and initializes new slots to `NULL`. * * @param[in,out] fdt Pointer to the file des

 * @note Expand table size to next multiple of 4 (but not exceeding DFS_FD_MAX)
 */
static int _fdt_slot_expand(struct dfs_fdtable *fdt, int fd)
{
    int nr;
    int index;
    struct dfs_file **fds = NULL;

    if (fd < fdt->maxfd)
    {
        return fd;
    }
    if (fd >= DFS_FD_MAX)
    {
        return -1;
    }

    nr = ((fd + 4) & ~3);
    if (nr > DFS_FD_MAX)
    {
        nr = DFS_FD_MAX;
    }
    fds = (struct dfs_file **)rt_realloc(fdt->fds, nr * sizeof(struct dfs_file *));
    if (!fds)
    {
        return -1;
    }

    /* clean the new allocated fds */
    for (index = fdt->maxfd; index < nr; index++)
    {
        fds[index] = NULL;
    }
    fdt->fds = fds;
    fdt->maxfd = nr;

    return fd;
}

/**
 * @brief Allocate an available file descriptor slot in the file descriptor table