libc-bottom-half/cloudlibc/src/libc/dirent/fdopendir.c

   1 // Copyright (c) 2015-2016 Nuxi, https://nuxi.nl/
   2 //
   3 // SPDX-License-Identifier: BSD-2-Clause
   4
   5 #include <wasi/api.h>
   6 #include <dirent.h>
   7 #include <errno.h>
   8 #include <stdlib.h>
   9
  10 #include "dirent_impl.h"
  11
  12 DIR *fdopendir(int fd) {
  13   // Allocate new directory object and read buffer.
  14   DIR *dirp = malloc(sizeof(*dirp));
  15   if (dirp == NULL)
  16     return NULL;
  17   dirp->buffer = malloc(DIRENT_DEFAULT_BUFFER_SIZE);
  18   if (dirp->buffer == NULL) {
  19     free(dirp);
  20     return NULL;
  21   }
  22
  23   // Ensure that this is really a directory by already loading the first
  24   // chunk of data.
  25   __wasi_errno_t error =
  26       // TODO: Remove the cast on `dirp->buffer` once the witx is updated with char8 support.
  27       __wasi_fd_readdir(fd, (uint8_t *)dirp->buffer, DIRENT_DEFAULT_BUFFER_SIZE,
  28                                 __WASI_DIRCOOKIE_START, &dirp->buffer_used);
  29   if (error != 0) {
  30     free(dirp->buffer);
  31     free(dirp);
  32     return NULL;
  33   }
  34
  35   // Initialize other members.
  36   dirp->fd = fd;
  37   dirp->cookie = __WASI_DIRCOOKIE_START;
  38   dirp->buffer_processed = 0;
  39   dirp->buffer_size = DIRENT_DEFAULT_BUFFER_SIZE;
  40   dirp->dirent = NULL;
  41   dirp->dirent_size = 1;
  42   return dirp;
  43 }