21 #include "fios.h" // opendir/readdir/closedir

    23 #include <errno.h>

    24 #include <sys/types.h>

    25 #include <sys/stat.h>

   609 /* Code below for windows version of opendir/readdir/closedir copied and

   610  * modified from Jan Wassenberg's GPL implementation posted over at

   611  * http://www.gamedev.net/community/forums/topic.asp?topic_id=364584&whichpage=1&#2398903 */

   612 

   613 /* suballocator - satisfies most requests with a reusable static instance.

   614  * this avoids hundreds of alloc/free which would fragment the heap.

   615  * To guarantee thread-safety, we fall back to malloc if the instance is

   616  * already in use (it's important to avoid suprises since this is such a

   617  * low-level routine). */

   618 static DIR _global_dir;

   619 static bool _global_dir_is_in_use = false;

   620 

   621 static inline DIR *dir_calloc(void)

   622 {

   623 	DIR *d;

   624 

   625 	if (_global_dir_is_in_use) {

   626 		d = calloc(1, sizeof(DIR));

   627 	} else {

   628 		_global_dir_is_in_use = true;

   629 		d = &_global_dir;

   630 		memset(d, 0, sizeof(DIR));

   631 	}

   632 	return d;

   633 }

   634 

   635 static inline void dir_free(DIR *d)

   636 {

   637 	if (d == &_global_dir) {

   638 		_global_dir_is_in_use = false;

   639 	} else {

   640 		free(d);

   641 	}

   642 }

   643 

   644 DIR *opendir(const char *path)

   645 {

   646 	char search_path[MAX_PATH];

   647 	DIR *d;

   648 	UINT sem = SetErrorMode(SEM_FAILCRITICALERRORS); // disable 'no-disk' message box

   649 	DWORD fa = GetFileAttributes(path);

   650 

   651 	/* not a directory or path not found */

   652 	if (fa == INVALID_FILE_ATTRIBUTES || (fa & FILE_ATTRIBUTE_DIRECTORY) == 0) {

   653 		errno = ENOENT;

   654 		return NULL;

   655 	}

   656 

   657 	d = dir_calloc();

   658 	if (d == NULL) {

   659 		errno = ENOMEM;

   660 		return NULL;

   661 	}

   662 

   663 	/* build search path for FindFirstFile */

   664 	snprintf(search_path, lengthof(search_path), "%s" PATHSEP "*", path);

   665 	d->hFind = FindFirstFile(search_path, &d->fd);

   666 	SetErrorMode(sem); // restore previous setting

   667 

   668 	if (d->hFind == INVALID_HANDLE_VALUE) {

   669 		/* not an error - the directory is just empty */

   670 		if (GetLastError() == ERROR_NO_MORE_FILES) return NULL;

   671 		dir_free(d);

   672 	}

   673 

   674 	d->ent.dir = d;

   675 	d->at_first_entry = true;

   676 	return d;

   677 }

   678 

   679 struct dirent *readdir(DIR *d)

   680 {

   681 	DWORD prev_err = GetLastError(); // avoid polluting last error

   682 

   683 	if (d->at_first_entry) {

   684 		/* the directory was empty when opened */

   685 		if (d->hFind == INVALID_HANDLE_VALUE) return NULL;

   686 		d->at_first_entry = false;

   687 		goto already_have_file;

   688 	}

   689 

   690 	/* Go until the end of directory or until a valid entry was found */

   691 	if (!FindNextFile(d->hFind, &d->fd)) { // determine cause and bail

   692 		if (GetLastError() == ERROR_NO_MORE_FILES) SetLastError(prev_err);

   693 		return NULL;

   694 	}

   695 

   696 already_have_file:

   697 	/* This entry has passed all checks; return information about it.

   698 	 * (note: d_name is a pointer; see struct dirent definition) */

   699 	d->ent.d_name = d->fd.cFileName;

   700 	return &d->ent;

   701 }

   702 

   703 int closedir(DIR *d)

   704 {

   705 	FindClose(d->hFind);

   706 	dir_free(d);

   707 	return 0;

   708 }

   709