zfs-builds-mm/zfs-0.8.3/lib/libzutil/zutil_nicenum.c
2020-03-01 19:43:35 +01:00

157 lines
4.3 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
*/
#include <math.h>
#include <stdio.h>
#include <libzutil.h>
/*
* Convert a number to an appropriately human-readable output.
*/
void
zfs_nicenum_format(uint64_t num, char *buf, size_t buflen,
enum zfs_nicenum_format format)
{
uint64_t n = num;
int index = 0;
const char *u;
const char *units[3][7] = {
[ZFS_NICENUM_1024] = {"", "K", "M", "G", "T", "P", "E"},
[ZFS_NICENUM_BYTES] = {"B", "K", "M", "G", "T", "P", "E"},
[ZFS_NICENUM_TIME] = {"ns", "us", "ms", "s", "?", "?", "?"}
};
const int units_len[] = {[ZFS_NICENUM_1024] = 6,
[ZFS_NICENUM_BYTES] = 6,
[ZFS_NICENUM_TIME] = 4};
const int k_unit[] = { [ZFS_NICENUM_1024] = 1024,
[ZFS_NICENUM_BYTES] = 1024,
[ZFS_NICENUM_TIME] = 1000};
double val;
if (format == ZFS_NICENUM_RAW) {
snprintf(buf, buflen, "%llu", (u_longlong_t)num);
return;
} else if (format == ZFS_NICENUM_RAWTIME && num > 0) {
snprintf(buf, buflen, "%llu", (u_longlong_t)num);
return;
} else if (format == ZFS_NICENUM_RAWTIME && num == 0) {
snprintf(buf, buflen, "%s", "-");
return;
}
while (n >= k_unit[format] && index < units_len[format]) {
n /= k_unit[format];
index++;
}
u = units[format][index];
/* Don't print zero latencies since they're invalid */
if ((format == ZFS_NICENUM_TIME) && (num == 0)) {
(void) snprintf(buf, buflen, "-");
} else if ((index == 0) || ((num %
(uint64_t)powl(k_unit[format], index)) == 0)) {
/*
* If this is an even multiple of the base, always display
* without any decimal precision.
*/
(void) snprintf(buf, buflen, "%llu%s", (u_longlong_t)n, u);
} else {
/*
* We want to choose a precision that reflects the best choice
* for fitting in 5 characters. This can get rather tricky when
* we have numbers that are very close to an order of magnitude.
* For example, when displaying 10239 (which is really 9.999K),
* we want only a single place of precision for 10.0K. We could
* develop some complex heuristics for this, but it's much
* easier just to try each combination in turn.
*/
int i;
for (i = 2; i >= 0; i--) {
val = (double)num /
(uint64_t)powl(k_unit[format], index);
/*
* Don't print floating point values for time. Note,
* we use floor() instead of round() here, since
* round can result in undesirable results. For
* example, if "num" is in the range of
* 999500-999999, it will print out "1000us". This
* doesn't happen if we use floor().
*/
if (format == ZFS_NICENUM_TIME) {
if (snprintf(buf, buflen, "%d%s",
(unsigned int) floor(val), u) <= 5)
break;
} else {
if (snprintf(buf, buflen, "%.*f%s", i,
val, u) <= 5)
break;
}
}
}
}
/*
* Convert a number to an appropriately human-readable output.
*/
void
zfs_nicenum(uint64_t num, char *buf, size_t buflen)
{
zfs_nicenum_format(num, buf, buflen, ZFS_NICENUM_1024);
}
/*
* Convert a time to an appropriately human-readable output.
* @num: Time in nanoseconds
*/
void
zfs_nicetime(uint64_t num, char *buf, size_t buflen)
{
zfs_nicenum_format(num, buf, buflen, ZFS_NICENUM_TIME);
}
/*
* Print out a raw number with correct column spacing
*/
void
zfs_niceraw(uint64_t num, char *buf, size_t buflen)
{
zfs_nicenum_format(num, buf, buflen, ZFS_NICENUM_RAW);
}
/*
* Convert a number of bytes to an appropriately human-readable output.
*/
void
zfs_nicebytes(uint64_t num, char *buf, size_t buflen)
{
zfs_nicenum_format(num, buf, buflen, ZFS_NICENUM_BYTES);
}