003 File Manager
Current Path:
/usr/src/cddl/contrib/opensolaris/lib/libcmdutils/common
usr
/
src
/
cddl
/
contrib
/
opensolaris
/
lib
/
libcmdutils
/
common
/
📁
..
📄
nicenum.c
(3.34 KB)
Editing: nicenum.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. * Copyright 2017 Jason king */ #include <stdio.h> #include <string.h> #include <sys/types.h> #include <sys/debug.h> #include "libcmdutils.h" /* The largest suffix that can fit, aka an exabyte (2^60 / 10^18) */ #define INDEX_MAX (6) /* Verify INDEX_MAX fits */ CTASSERT(INDEX_MAX * 10 < sizeof (uint64_t) * 8); void nicenum_scale(uint64_t n, size_t units, char *buf, size_t buflen, uint32_t flags) { uint64_t divamt = 1024; uint64_t divisor = 1; int index = 0; int rc = 0; char u; if (units == 0) units = 1; if (n > 0) { n *= units; if (n < units) goto overflow; } if (flags & NN_DIVISOR_1000) divamt = 1000; /* * This tries to find the suffix S(n) such that * S(n) <= n < S(n+1), where S(n) = 2^(n*10) | 10^(3*n) * (i.e. 1024/1000, 1,048,576/1,000,000, etc). Stop once S(n) * is the largest prefix supported (i.e. don't bother computing * and checking S(n+1). Since INDEX_MAX should be the largest * suffix that fits (currently an exabyte), S(INDEX_MAX + 1) is * never checked as it would overflow. */ while (index < INDEX_MAX) { uint64_t newdiv = divisor * divamt; /* CTASSERT() guarantee these never trip */ VERIFY3U(newdiv, >=, divamt); VERIFY3U(newdiv, >=, divisor); if (n < newdiv) break; divisor = newdiv; index++; } u = " KMGTPE"[index]; if (index == 0) { rc = snprintf(buf, buflen, "%llu", n); } else if (n % divisor == 0) { /* * If this is an even multiple of the base, always display * without any decimal precision. */ rc = snprintf(buf, buflen, "%llu%c", n / divisor, 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--) { if ((rc = snprintf(buf, buflen, "%.*f%c", i, (double)n / divisor, u)) <= 5) break; } } if (rc + 1 > buflen || rc < 0) goto overflow; return; overflow: /* prefer a more verbose message if possible */ if (buflen > 10) (void) strlcpy(buf, "<overflow>", buflen); else (void) strlcpy(buf, "??", buflen); } void nicenum(uint64_t num, char *buf, size_t buflen) { nicenum_scale(num, 1, buf, buflen, 0); }
Upload File
Create Folder