#if CONFIG_xxx -> #if ENABLE_xxx

[oweals/busybox.git] / libbb / human_readable.c

diff --git a/libbb/human_readable.c b/libbb/human_readable.c
index 36783fac7d8a9efca5d018f716fabf1bb01acdf1..ff1b5514118fcb49eef1cde03c288313820cc85c 100644 (file)
--- a/libbb/human_readable.c
+++ b/libbb/human_readable.c
@@ -1,53 +1,89 @@
 /* vi: set sw=4 ts=4: */
 /*
- * Utility routines.
+ * June 30, 2001                 Manuel Novoa III
  *
- * Copyright (C) tons of folks.  Tracking down who wrote what
- * isn't something I'm going to worry about...  If you wrote something
- * here, please feel free to acknowledge your work.
+ * All-integer version (hey, not everyone has floating point) of
+ * make_human_readable_str, modified from similar code I had written
+ * for busybox several months ago.
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ * Notes:
+ *   1) I'm using an unsigned long long to hold the product size * block_size,
+ *      as df (which calls this routine) could request a representation of a
+ *      partition size in bytes > max of unsigned long.  If long longs aren't
+ *      available, it would be possible to do what's needed using polynomial
+ *      representations (say, powers of 1024) and manipulating coefficients.
+ *      The base ten "bytes" output could be handled similarly.
  *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
+ *   2) This routine always outputs a decimal point and a tenths digit when
+ *      display_unit != 0.  Hence, it isn't uncommon for the returned string
+ *      to have a length of 5 or 6.
  *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- * Based in part on code from sash, Copyright (c) 1999 by David I. Bell 
- * Permission has been granted to redistribute this code under the GPL.
+ *      It might be nice to add a flag to indicate no decimal digits in
+ *      that case.  This could be either an additional parameter, or a
+ *      special value of display_unit.  Such a flag would also be nice for du.
  *
+ *      Some code to omit the decimal point and tenths digit is sketched out
+ *      and "#if 0"'d below.
  */
 
 #include <stdio.h>
 #include "libbb.h"
 
-static char buffer[10];
-static const char *suffixes[] = { "", "k", "M", "G", "T" };
-
-const char *make_human_readable_str(unsigned long val, unsigned long not_hr)
+const char *make_human_readable_str(unsigned long long size,
+       unsigned long block_size, unsigned long display_unit)
 {
-       int suffix, base;
-
-       if (not_hr)
-               sprintf(buffer, "%lu", val);
-       else
-               for (suffix = 0, base = 1; suffix < 5; suffix++, base <<= 10) {
-                       if (val < (base << 10)) {
-                               if (suffix && val < 10 * base)
-                                       sprintf(buffer, "%lu.%lu%s", val / base,
-                                                       (val % base) * 10 / base, suffixes[suffix]);
-                               else
-                                       sprintf(buffer, "%lu%s", val / base, suffixes[suffix]);
-                               break;
+       /* The code will adjust for additional (appended) units. */
+       static const char zero_and_units[] = { '0', 0, 'k', 'M', 'G', 'T' };
+       static const char fmt[] = "%llu";
+       static const char fmt_tenths[] = "%llu.%d%c";
+
+       static char str[21];            /* Sufficient for 64 bit unsigned integers. */
+
+       unsigned long long val;
+       int frac;
+       const char *u;
+       const char *f;
+
+       u = zero_and_units;
+       f = fmt;
+       frac = 0;
+
+       val = size * block_size;
+       if (val == 0) {
+               return u;
+       }
+
+       if (display_unit) {
+               val += display_unit/2;  /* Deal with rounding. */
+               val /= display_unit;    /* Don't combine with the line above!!! */
+       } else {
+               ++u;
+               while ((val >= 1024)
+                && (u < zero_and_units + sizeof(zero_and_units) - 1)
+               ) {
+                       f = fmt_tenths;
+                       ++u;
+                       frac = (((int)(val % 1024)) * 10 + 1024/2) / 1024;
+                       val /= 1024;
+               }
+               if (frac >= 10) {               /* We need to round up here. */
+                       ++val;
+                       frac = 0;
+               }
+#if 0
+               /* Sample code to omit decimal point and tenths digit. */
+               if ( /* no_tenths */ 1 ) {
+                       if ( frac >= 5 ) {
+                               ++val;
                        }
+                       f = "%llu%*c" /* fmt_no_tenths */ ;
+                       frac = 1;
                }
+#endif
+       }
+
+       /* If f==fmt then 'frac' and 'u' are ignored. */
+       snprintf(str, sizeof(str), f, val, frac, *u);
 
-       return buffer;
+       return str;
 }