10a055120SJason King /*
20a055120SJason King * CDDL HEADER START
30a055120SJason King *
40a055120SJason King * The contents of this file are subject to the terms of the
50a055120SJason King * Common Development and Distribution License (the "License").
60a055120SJason King * You may not use this file except in compliance with the License.
70a055120SJason King *
80a055120SJason King * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
90a055120SJason King * or http://www.opensolaris.org/os/licensing.
100a055120SJason King * See the License for the specific language governing permissions
110a055120SJason King * and limitations under the License.
120a055120SJason King *
130a055120SJason King * When distributing Covered Code, include this CDDL HEADER in each
140a055120SJason King * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
150a055120SJason King * If applicable, add the following below this CDDL HEADER, with the
160a055120SJason King * fields enclosed by brackets "[]" replaced with your own identifying
170a055120SJason King * information: Portions Copyright [yyyy] [name of copyright owner]
180a055120SJason King *
190a055120SJason King * CDDL HEADER END
200a055120SJason King */
210a055120SJason King
220a055120SJason King /*
230a055120SJason King * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
240a055120SJason King * Copyright 2017 Jason king
25*a61ed2ceSHans Rosenfeld * Copyright 2019, Joyent, Inc.
260a055120SJason King */
270a055120SJason King
280a055120SJason King #include <stdio.h>
290a055120SJason King #include <string.h>
300a055120SJason King #include <sys/types.h>
310a055120SJason King #include <sys/debug.h>
320a055120SJason King #include "libcmdutils.h"
330a055120SJason King
340a055120SJason King /* The largest suffix that can fit, aka an exabyte (2^60 / 10^18) */
350a055120SJason King #define INDEX_MAX (6)
360a055120SJason King
370a055120SJason King /* Verify INDEX_MAX fits */
380a055120SJason King CTASSERT(INDEX_MAX * 10 < sizeof (uint64_t) * 8);
390a055120SJason King
400a055120SJason King void
nicenum_scale(uint64_t n,size_t units,char * buf,size_t buflen,uint32_t flags)410a055120SJason King nicenum_scale(uint64_t n, size_t units, char *buf, size_t buflen,
420a055120SJason King uint32_t flags)
430a055120SJason King {
440a055120SJason King uint64_t divamt = 1024;
450a055120SJason King uint64_t divisor = 1;
460a055120SJason King int index = 0;
470a055120SJason King int rc = 0;
48*a61ed2ceSHans Rosenfeld const char *spc = "";
490a055120SJason King char u;
500a055120SJason King
51*a61ed2ceSHans Rosenfeld if (flags & NN_UNIT_SPACE) {
52*a61ed2ceSHans Rosenfeld spc = " ";
53*a61ed2ceSHans Rosenfeld }
54*a61ed2ceSHans Rosenfeld
550a055120SJason King if (units == 0)
560a055120SJason King units = 1;
570a055120SJason King
580a055120SJason King if (n > 0) {
590a055120SJason King n *= units;
600a055120SJason King if (n < units)
610a055120SJason King goto overflow;
620a055120SJason King }
630a055120SJason King
640a055120SJason King if (flags & NN_DIVISOR_1000)
650a055120SJason King divamt = 1000;
660a055120SJason King
670a055120SJason King /*
680a055120SJason King * This tries to find the suffix S(n) such that
690a055120SJason King * S(n) <= n < S(n+1), where S(n) = 2^(n*10) | 10^(3*n)
700a055120SJason King * (i.e. 1024/1000, 1,048,576/1,000,000, etc). Stop once S(n)
710a055120SJason King * is the largest prefix supported (i.e. don't bother computing
720a055120SJason King * and checking S(n+1). Since INDEX_MAX should be the largest
730a055120SJason King * suffix that fits (currently an exabyte), S(INDEX_MAX + 1) is
740a055120SJason King * never checked as it would overflow.
750a055120SJason King */
760a055120SJason King while (index < INDEX_MAX) {
770a055120SJason King uint64_t newdiv = divisor * divamt;
780a055120SJason King
790a055120SJason King /* CTASSERT() guarantee these never trip */
800a055120SJason King VERIFY3U(newdiv, >=, divamt);
810a055120SJason King VERIFY3U(newdiv, >=, divisor);
820a055120SJason King
830a055120SJason King if (n < newdiv)
840a055120SJason King break;
850a055120SJason King
860a055120SJason King divisor = newdiv;
870a055120SJason King index++;
880a055120SJason King }
890a055120SJason King
900a055120SJason King u = " KMGTPE"[index];
910a055120SJason King
920a055120SJason King if (index == 0) {
93*a61ed2ceSHans Rosenfeld rc = snprintf(buf, buflen, "%llu%s", n, spc);
940a055120SJason King } else if (n % divisor == 0) {
950a055120SJason King /*
960a055120SJason King * If this is an even multiple of the base, always display
970a055120SJason King * without any decimal precision.
980a055120SJason King */
99*a61ed2ceSHans Rosenfeld rc = snprintf(buf, buflen, "%llu%s%c", n / divisor, spc, u);
1000a055120SJason King } else {
1010a055120SJason King /*
1020a055120SJason King * We want to choose a precision that reflects the best choice
103*a61ed2ceSHans Rosenfeld * for fitting in the buffer. This can get rather tricky
1040a055120SJason King * when we have numbers that are very close to an order of
1050a055120SJason King * magnitude. For example, when displaying 10239 (which is
1060a055120SJason King * really 9.999K), we want only a single place of precision
1070a055120SJason King * for 10.0K. We could develop some complex heuristics for
1080a055120SJason King * this, but it's much easier just to try each combination
1090a055120SJason King * in turn.
1100a055120SJason King */
1110a055120SJason King int i;
1120a055120SJason King for (i = 2; i >= 0; i--) {
113*a61ed2ceSHans Rosenfeld if ((rc = snprintf(buf, buflen, "%.*f%s%c", i,
114*a61ed2ceSHans Rosenfeld (double)n / divisor, spc, u)) <= (buflen - 1))
1150a055120SJason King break;
1160a055120SJason King }
1170a055120SJason King }
1180a055120SJason King
1190a055120SJason King if (rc + 1 > buflen || rc < 0)
1200a055120SJason King goto overflow;
1210a055120SJason King
1220a055120SJason King return;
1230a055120SJason King
1240a055120SJason King overflow:
1250a055120SJason King /* prefer a more verbose message if possible */
1260a055120SJason King if (buflen > 10)
1270a055120SJason King (void) strlcpy(buf, "<overflow>", buflen);
1280a055120SJason King else
1290a055120SJason King (void) strlcpy(buf, "??", buflen);
1300a055120SJason King }
1310a055120SJason King
1320a055120SJason King void
nicenum(uint64_t num,char * buf,size_t buflen)1330a055120SJason King nicenum(uint64_t num, char *buf, size_t buflen)
1340a055120SJason King {
1350a055120SJason King nicenum_scale(num, 1, buf, buflen, 0);
1360a055120SJason King }
137