/***********************************************************************

*                                                                      *

*               This software is part of the ast package               *

*          Copyright (c) 1985-2011 AT&T Intellectual Property          *

*                      and is licensed under the                       *

*                 Eclipse Public License, Version 1.0                  *

*                    by AT&T Intellectual Property                     *

*                                                                      *

*                A copy of the License is available at                 *

*          http://www.eclipse.org/org/documents/epl-v10.html           *

*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *

*                                                                      *

*              Information and Software Systems Research               *

*                            AT&T Research                             *

*                           Florham Park NJ                            *

*                                                                      *

*                 Glenn Fowler <gsf@research.att.com>                  *

*                  David Korn <dgk@research.att.com>                   *

*                   Phong Vo <kpv@research.att.com>                    *

*                                                                      *

***********************************************************************/

#pragma prototyped

#include "dirlib.h"

#if _dir_ok || _lib_getdents

NoN(getdents)

#else

/*

 * getdents

 *

 * read directory entries into directory block

 *

 * NOTE: directory entries must fit within DIRBLKSIZ boundaries

 */

#ifndef MAXNAMLEN

#define MAXNAMLEN	255

#endif

#if _lib_dirread

extern int		dirread(int, char*, int);

#endif

#if _lib_getdirentries

extern int		getdirentries(int, char*, int, long*);

#endif

ssize_t

getdents(int fd, void* buf, size_t siz)

{

	struct stat		st;

	if (siz < DIRBLKSIZ)

	{

		errno = EINVAL;

		return(-1);

	}

	if (fstat(fd, &st)) return(-1);

	if (!S_ISDIR(st.st_mode))

	{

#ifdef ENOTDIR

		errno = ENOTDIR;

#else

		errno = EBADF;

#endif

		return(-1);

	}

#if _lib_getdirentries

	{

		long		off;

		return(getdirentries(fd, buf, siz, &off));

	}

#else

#if _lib_dirread

	{

		register char*		sp;	/* system */

		register struct dirent*	up;	/* user */

		char*			u;

		int			n;

		int			m;

		int			i;

		m = (siz * 6) / 10;

		m = roundof(m, 8);

		sp = (char*)buf + siz - m - 1;

		if (!(n = dirread(fd, sp, m))) return(0);

		if (n > 0)

		{

			up = (struct dirent*)buf;

			sp[n] = 0;

			while (sp < (char*)buf + siz - m + n)

			{

				i = 0;

				while (*sp >= '0' && *sp <= '9')

					i = 10 * i + *sp++ - '0';

				while (*sp && *sp != '\t') sp++;

				if (*sp++)

				{

					up->d_fileno = i;

					u = up->d_name;

					while ((*u = *sp++) && u < up->d_name + MAXNAMLEN) u++;

					*u = 0;

					up->d_reclen = sizeof(struct dirent) - sizeof(up->d_name) + (up->d_namlen = u - up->d_name) + 1;

					up->d_reclen = roundof(up->d_reclen, 8);

					up = (struct dirent*)((char*)up + up->d_reclen);

				}

			}

			return((char*)up - (char*)buf);

		}

	}

#else

#if _mem_d_reclen_direct

	return(read(fd, buf, siz));

#else

	{

#define MAXREC	roundof(sizeof(*up)-sizeof(up->d_name)+sizeof(sp->d_name)+1,8)

		register struct direct*	sp;	/* system */

		register struct dirent*	up;	/* user */

		register char*		s;

		register char*		u;

		int			n;

		int			m;

		char			tmp[sizeof(sp->d_name) + 1];

		/*

		 * we assume sizeof(struct dirent) > sizeof(struct direct)

		 */

		up = (struct dirent*)buf;

		n = (siz / MAXREC) * sizeof(struct direct);

		if ((!(m = n & ~511) || m < MAXREC) && (!(m = n & ~255) || m < MAXREC)) m = n;

		do

		{

			if ((n = read(fd, (char*)buf + siz - m, m)) <= 0) break;

			sp = (struct direct*)((char*)buf + siz - m);

			while (sp < (struct direct*)((char*)buf + siz - m + n))

			{

				if (sp->d_ino)

				{

					up->d_fileno = sp->d_ino;

					s = sp->d_name;

					u = tmp;

					while (s < sp->d_name + sizeof(sp->d_name) && *s)

						*u++ = *s++;

					*u = 0;

					strcpy(up->d_name, tmp);

					up->d_reclen = sizeof(struct dirent) - sizeof(up->d_name) + (up->d_namlen = u - tmp) + 1;

					up->d_reclen = roundof(up->d_reclen, 8);

					up = (struct dirent*)((char*)up + up->d_reclen);

				}

				sp++;

			}

		} while (up == (struct dirent*)buf);

		return((char*)up - (char*)buf);

	}

#endif

#endif

#endif

}

#endif