xref: /freebsd/sys/contrib/openzfs/tests/zfs-tests/include/math.shlib (revision 13ec1e3155c7e9bf037b12af186351b7fa9b9450)
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' = $(echo "if ($2 > $a) 1 else 0" | 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' = $(echo "scale=2; if ($p >= $percent) 1 else 0" | bc) ]] && \
41	    return 0
42
43	return 1
44}
45
46#
47# Return 0 if value is within +/-tolerance of target.
48# Return 1 if value exceeds our tolerance.
49# For use like this:
50#
51# Do $action if value is within the tolerance from target passed in:
52#	within_tolerance VAL TAR TOL && $action
53# Do $action if value surpasses the tolerance from target passed in:
54#	within_tolerance VAL TAR TOL || $action
55#
56function within_tolerance #value #target #tolerance
57{
58	typeset val=$1
59	typeset target=$2
60	typeset tol=$3
61
62	typeset diff=$((abs(val - target)))
63	log_note "Checking if $val is within +/-$tol of $target (diff: $diff)"
64	((diff <= tol)) && return 0
65
66	return 1
67}
68
69#
70# Return 0 if the human readable string of the form <value>[suffix] can
71# be converted to bytes.  Allow suffixes are shown in the table below.
72#
73function to_bytes
74{
75	typeset size=$1
76	typeset value=$(echo "$size" | grep -o '[0-9]\+')
77
78	case $size in
79		*PB|*pb|*P|*p)	factor='1024^5'	;;
80		*TB|*tb|*T|*t)	factor='1024^4'	;;
81		*GB|*gb|*G|*g)	factor='1024^3'	;;
82		*MB|*mb|*M|*m)	factor='1024^2'	;;
83		*KB|*kb|*K|*k)	factor='1024^1'	;;
84		*B|*b)		factor='1024^0'	;;
85		*[!0-9.]*)	return 1 ;;
86		*)		factor='1024^0'	;;
87	esac
88
89	echo "$value * ($factor)" | bc
90
91	return 0
92}
93
94#
95# Verify $a is equal to $b, otherwise raise an error specifying
96# the $type of values being compared
97#
98function verify_eq # <a> <b> <type>
99{
100	typeset a=$1
101	typeset b=$2
102	typeset type=$3
103
104	if [[ $a -ne $b ]]; then
105		log_fail "Compared $type should be equal: $a != $b"
106	fi
107}
108
109#
110# Verify $a is not equal to $b, otherwise raise an error specifying
111# the $type of values being compared
112#
113function verify_ne # <a> <b> <type>
114{
115	typeset a=$1
116	typeset b=$2
117	typeset type=$3
118
119	if [[ $a -eq $b ]]; then
120		log_fail "Compared $type should be not equal: $a == $b"
121	fi
122}
123
124# A simple function to get a random number between two bounds (inclusive)
125#
126# Probably not the most efficient for large ranges, but it's okay.
127#
128# Note since we're using $RANDOM, 32767 is the largest number we
129# can accept as the upper bound.
130#
131# $1 lower bound
132# $2 upper bound
133function random_int_between
134{
135	typeset -i min=$1
136	typeset -i max=$2
137	typeset -i rand=0
138
139	while [[ $rand -lt $min ]] ; do
140		rand=$(( $RANDOM % $max + 1))
141	done
142
143	echo $rand
144}
145