xref: /freebsd/sys/contrib/openzfs/tests/zfs-tests/include/math.shlib (revision af23369a6deaaeb612ab266eb88b8bb8d560c322)
1#
2# This file and its contents are supplied under the terms of the
3# Common Development and Distribution License ("CDDL"), version 1.0.
4# You may only use this file in accordance with the terms of version
5# 1.0 of the CDDL.
6#
7# A full copy of the text of the CDDL should have accompanied this
8# source.  A copy of the CDDL is also available via the Internet at
9# http://www.illumos.org/license/CDDL.
10#
11
12#
13# Copyright (c) 2012, 2016 by Delphix. All rights reserved.
14#
15
16#
17# Return 0 if the percentage difference between $a and $b is $percent or
18# greater. Return 1 if the percentage is lower or if we would divide by
19# zero. For use like this:
20#
21# Do $action if the calculated percentage is greater or equal to that passed in:
22#	within_percent A B P && $action
23# Do $action if the calculated percentage is less than that passed in:
24#	within_percent A B P || $action
25#
26function within_percent
27{
28	typeset a=$1
29	typeset b=$1
30	typeset percent=$3
31
32	# Set $a or $b to $2 such that a >= b
33	[ 1 -eq $(echo "$2 > $a" | bc) ] && a=$2 || b=$2
34
35	# Prevent division by 0
36	[[ $a =~ [1-9] ]] || return 1
37
38	typeset p=$(echo "scale=2; $b * 100 / $a" | bc)
39	log_note "Comparing $a and $b given $percent% (calculated: $p%)"
40	[ 1 -eq $(echo "scale=2; $p >= $percent" | bc) ]
41}
42
43#
44# Return 0 if value is within +/-tolerance of target.
45# Return 1 if value exceeds our tolerance.
46# For use like this:
47#
48# Do $action if value is within the tolerance from target passed in:
49#	within_tolerance VAL TAR TOL && $action
50# Do $action if value surpasses the tolerance from target passed in:
51#	within_tolerance VAL TAR TOL || $action
52#
53function within_tolerance #value #target #tolerance
54{
55	typeset val=$1
56	typeset target=$2
57	typeset tol=$3
58
59	typeset diff=$((abs(val - target)))
60	log_note "Checking if $val is within +/-$tol of $target (diff: $diff)"
61	((diff <= tol))
62}
63
64#
65# Return 0 if the human readable string of the form <value>[suffix] can
66# be converted to bytes.  Allow suffixes are shown in the table below.
67#
68function to_bytes
69{
70	typeset size=$1
71	typeset value=$(echo "$size" | grep -o '[0-9]\+')
72
73	case $size in
74		*PB|*pb|*P|*p)	factor='1024^5'	;;
75		*TB|*tb|*T|*t)	factor='1024^4'	;;
76		*GB|*gb|*G|*g)	factor='1024^3'	;;
77		*MB|*mb|*M|*m)	factor='1024^2'	;;
78		*KB|*kb|*K|*k)	factor='1024^1'	;;
79		*B|*b)		factor='1024^0'	;;
80		*[!0-9.]*)	return 1 ;;
81		*)		factor='1024^0'	;;
82	esac
83
84	echo "$value * ($factor)" | bc
85
86	return 0
87}
88
89#
90# Verify $a is equal to $b, otherwise raise an error specifying
91# the $type of values being compared
92#
93function verify_eq # <a> <b> <type>
94{
95	typeset a=$1
96	typeset b=$2
97	typeset type=$3
98
99	if [[ $a -ne $b ]]; then
100		log_fail "Compared $type should be equal: $a != $b"
101	fi
102}
103
104#
105# Verify $a is not equal to $b, otherwise raise an error specifying
106# the $type of values being compared
107#
108function verify_ne # <a> <b> <type>
109{
110	typeset a=$1
111	typeset b=$2
112	typeset type=$3
113
114	if [[ $a -eq $b ]]; then
115		log_fail "Compared $type should be not equal: $a == $b"
116	fi
117}
118
119# A simple function to get a random number between two bounds (inclusive)
120#
121# Probably not the most efficient for large ranges, but it's okay.
122#
123# Note since we're using $RANDOM, 32767 is the largest number we
124# can accept as the upper bound.
125#
126# $1 lower bound
127# $2 upper bound
128function random_int_between
129{
130	typeset -i min=$1
131	typeset -i max=$2
132	typeset -i rand=0
133
134	while [[ $rand -lt $min ]] ; do
135		rand=$(( $RANDOM % $max + 1))
136	done
137
138	echo $rand
139}
140