* Copyright (c) 1989, 1993, 1994

/* $NetBSD: du.c,v 1.36 2012/03/11 11:23:20 shattered Exp $ */

/*
* Copyright (c) 1989, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Newcomb.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1989, 1993, 1994\
The Regents of the University of California. All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)du.c 8.5 (Berkeley) 5/4/95";
#else
__RCSID("$NetBSD: du.c,v 1.36 2012/03/11 11:23:20 shattered Exp $");
#endif
#endif /* not lint */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>

#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <fts.h>
#include <inttypes.h>
#include <util.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>

/* Count inodes or file size */
#define COUNT (iflag ? 1 : p->fts_statp->st_blocks)

static int linkchk(dev_t, ino_t);
static void prstat(const char *, int64_t);
__dead static void usage(void);

static int hflag, iflag;
static long blocksize;

int
main(int argc, char *argv[])
{
FTS *fts;
FTSENT *p;
int64_t totalblocks;
int ftsoptions, listfiles;
int depth;
int Hflag, Lflag, aflag, ch, cflag, dflag, gkmflag, nflag, rval, sflag;
const char *noargv[2];

Hflag = Lflag = aflag = cflag = dflag = gkmflag = nflag = sflag = 0;
totalblocks = 0;
ftsoptions = FTS_PHYSICAL;
depth = INT_MAX;
while ((ch = getopt(argc, argv, "HLPacd:ghikmnrsx")) != -1)
switch (ch) {
case 'H':
Hflag = 1;
Lflag = 0;
break;
case 'L':
Lflag = 1;
Hflag = 0;
break;
case 'P':
Hflag = Lflag = 0;
break;
case 'a':
aflag = 1;
break;
case 'c':
cflag = 1;
break;
case 'd':
dflag = 1;
depth = atoi(optarg);
if (depth < 0 || depth > SHRT_MAX) {
warnx("invalid argument to option d: %s",
optarg);
usage();
}
break;
case 'g':
blocksize = 1024 * 1024 * 1024;
gkmflag = 1;
break;
case 'h':
hflag = 1;
break;
case 'i':
iflag = 1;
break;
case 'k':
blocksize = 1024;
gkmflag = 1;
break;
case 'm':
blocksize = 1024 * 1024;
gkmflag = 1;
break;
case 'n':
nflag = 1;
break;
case 'r':
break;
case 's':
sflag = 1;
break;
case 'x':
ftsoptions |= FTS_XDEV;
break;
case '?':
default:
usage();
}
argc -= optind;
argv += optind;

/*
* XXX
* Because of the way that fts(3) works, logical walks will not count
* the blocks actually used by symbolic links. We rationalize this by
* noting that users computing logical sizes are likely to do logical
* copies, so not counting the links is correct. The real reason is
* that we'd have to re-implement the kernel's symbolic link traversing
* algorithm to get this right. If, for example, you have relative
* symbolic links referencing other relative symbolic links, it gets
* very nasty, very fast. The bottom line is that it's documented in
* the man page, so it's a feature.
*/
if (Hflag)
ftsoptions |= FTS_COMFOLLOW;
if (Lflag) {
ftsoptions &= ~FTS_PHYSICAL;
ftsoptions |= FTS_LOGICAL;
}

listfiles = 0;
if (aflag) {
if (sflag || dflag)
usage();
listfiles = 1;
} else if (sflag) {
if (dflag)
usage();
depth = 0;
}

if (!*argv) {
noargv[0] = ".";
noargv[1] = NULL;
argv = __UNCONST(noargv);
}

if (!gkmflag)
(void)getbsize(NULL, &blocksize);
blocksize /= 512;

if ((fts = fts_open(argv, ftsoptions, NULL)) == NULL)
err(1, "fts_open `%s'", *argv);

for (rval = 0; (p = fts_read(fts)) != NULL;) {
if (nflag) {
switch (p->fts_info) {
case FTS_NS:
case FTS_SLNONE:
/* nothing */
break;
default:
if (p->fts_statp->st_flags & UF_NODUMP) {
fts_set(fts, p, FTS_SKIP);
continue;
}
}
}
switch (p->fts_info) {
case FTS_D: /* Ignore. */
break;
case FTS_DP:
p->fts_parent->fts_number +=
p->fts_number += COUNT;
if (cflag)
totalblocks += COUNT;
/*
* If listing each directory, or not listing files
* or directories and this is post-order of the
* root of a traversal, display the total.
*/
if (p->fts_level <= depth
|| (!listfiles && !p->fts_level))
prstat(p->fts_path, p->fts_number);
break;
case FTS_DC: /* Ignore. */
break;
case FTS_DNR: /* Warn, continue. */
case FTS_ERR:
case FTS_NS:
warnx("%s: %s", p->fts_path, strerror(p->fts_errno));
rval = 1;
break;
default:
if (p->fts_statp->st_nlink > 1 &&
linkchk(p->fts_statp->st_dev, p->fts_statp->st_ino))
break;
/*
* If listing each file, or a non-directory file was
* the root of a traversal, display the total.
*/
if (listfiles || !p->fts_level)
prstat(p->fts_path, COUNT);
p->fts_parent->fts_number += COUNT;
if (cflag)
totalblocks += COUNT;
}
}
if (errno)
err(1, "fts_read");
if (cflag)
prstat("total", totalblocks);
exit(rval);
}

static void
prstat(const char *fname, int64_t blocks)
{
if (iflag) {
(void)printf("%" PRId64 "\t%s\n", blocks, fname);
return;
}

if (hflag) {
char buf[5];
int64_t sz = blocks * 512;

humanize_number(buf, sizeof(buf), sz, "", HN_AUTOSCALE,
HN_B | HN_NOSPACE | HN_DECIMAL);

(void)printf("%s\t%s\n", buf, fname);
} else
(void)printf("%" PRId64 "\t%s\n",
howmany(blocks, (int64_t)blocksize),
fname);
}

static int
linkchk(dev_t dev, ino_t ino)
{
static struct entry {
dev_t dev;
ino_t ino;
} *htable;
static int htshift; /* log(allocated size) */
static int htmask; /* allocated size - 1 */
static int htused; /* 2*number of insertions */
static int sawzero; /* Whether zero is in table or not */
int h, h2;
uint64_t tmp;
/* this constant is (1<<64)/((1+sqrt(5))/2)
* aka (word size)/(golden ratio)
*/
const uint64_t HTCONST = 11400714819323198485ULL;
const int HTBITS = CHAR_BIT * sizeof(tmp);

/* Never store zero in hashtable */
if (dev == 0 && ino == 0) {
h = sawzero;
sawzero = 1;
return h;
}

/* Extend hash table if necessary, keep load under 0.5 */
if (htused<<1 >= htmask) {
struct entry *ohtable;

if (!htable)
htshift = 10; /* starting hashtable size */
else
htshift++; /* exponential hashtable growth */

htmask = (1 << htshift) - 1;
htused = 0;

ohtable = htable;
htable = calloc(htmask+1, sizeof(*htable));
if (!htable)
err(1, "calloc");

/* populate newly allocated hashtable */
if (ohtable) {
int i;
for (i = 0; i <= htmask>>1; i++)
if (ohtable[i].ino || ohtable[i].dev)
linkchk(ohtable[i].dev, ohtable[i].ino);
free(ohtable);
}
}

/* multiplicative hashing */
tmp = dev;
tmp <<= HTBITS>>1;
tmp |= ino;
tmp *= HTCONST;
h = tmp >> (HTBITS - htshift);
h2 = 1 | ( tmp >> (HTBITS - (htshift<<1) - 1)); /* must be odd */

/* open address hashtable search with double hash probing */
while (htable[h].ino || htable[h].dev) {
if ((htable[h].ino == ino) && (htable[h].dev == dev))
return 1;
h = (h + h2) & htmask;
}

/* Insert the current entry into hashtable */
htable[h].dev = dev;
htable[h].ino = ino;
htused++;
return 0;
}

static void
usage(void)
{

(void)fprintf(stderr,
"usage: du [-H | -L | -P] [-a | -d depth | -s] [-cghikmnrx] [file ...]\n");
exit(1);
}