FreeBSD/Linux Kernel Cross Reference
sys/contrib/openzfs/tests/zfs-tests/include/math.shlib

     #
     # This file and its contents are supplied under the terms of the
     # Common Development and Distribution License ("CDDL"), version 1.0.
     # You may only use this file in accordance with the terms of version
     # 1.0 of the CDDL.
     #
     # A full copy of the text of the CDDL should have accompanied this
     # source.  A copy of the CDDL is also available via the Internet at
     # http://www.illumos.org/license/CDDL.
    #
    
    #
    # Copyright (c) 2012, 2016 by Delphix. All rights reserved.
    #
    
    #
    # Return 0 if the percentage difference between $a and $b is $percent or
    # greater. Return 1 if the percentage is lower or if we would divide by
    # zero. For use like this:
    #
    # Do $action if the calculated percentage is greater or equal to that passed in:
    #       within_percent A B P && $action
    # Do $action if the calculated percentage is less than that passed in:
    #       within_percent A B P || $action
    #
    function within_percent
    {
            typeset a=$1
            typeset b=$1
            typeset percent=$3
    
            # Set $a or $b to $2 such that a >= b
            [ 1 -eq $(echo "$2 > $a" | bc) ] && a=$2 || b=$2
    
            # Prevent division by 0
            [[ $a =~ [1-9] ]] || return 1
    
            typeset p=$(echo "scale=2; $b * 100 / $a" | bc)
            log_note "Comparing $a and $b given $percent% (calculated: $p%)"
            [ 1 -eq $(echo "scale=2; $p >= $percent" | bc) ]
    }
    
    #
    # Return 0 if value is within +/-tolerance of target.
    # Return 1 if value exceeds our tolerance.
    # For use like this:
    #
    # Do $action if value is within the tolerance from target passed in:
    #       within_tolerance VAL TAR TOL && $action
    # Do $action if value surpasses the tolerance from target passed in:
    #       within_tolerance VAL TAR TOL || $action
    #
    function within_tolerance #value #target #tolerance
    {
            typeset val=$1
            typeset target=$2
            typeset tol=$3
    
            typeset diff=$((abs(val - target)))
            log_note "Checking if $val is within +/-$tol of $target (diff: $diff)"
            ((diff <= tol))
    }
    
    #
    # Return 0 if the human readable string of the form <value>[suffix] can
    # be converted to bytes.  Allow suffixes are shown in the table below.
    #
    function to_bytes
    {
            typeset size=$1
            typeset value=$(echo "$size" | grep -o '[0-9]\+')
    
            case $size in
                    *PB|*pb|*P|*p)  factor='1024^5' ;;
                    *TB|*tb|*T|*t)  factor='1024^4' ;;
                    *GB|*gb|*G|*g)  factor='1024^3' ;;
                    *MB|*mb|*M|*m)  factor='1024^2' ;;
                    *KB|*kb|*K|*k)  factor='1024^1' ;;
                    *B|*b)          factor='1024^0' ;;
                    *[!0-9.]*)      return 1 ;;
                    *)              factor='1024^0' ;;
            esac
    
            echo "$value * ($factor)" | bc
    
            return 0
    }
    
    #
    # Verify $a is equal to $b, otherwise raise an error specifying
    # the $type of values being compared
    #
    function verify_eq # <a> <b> <type>
    {
            typeset a=$1
            typeset b=$2
            typeset type=$3
    
            if [[ $a -ne $b ]]; then
                   log_fail "Compared $type should be equal: $a != $b"
           fi
   }
   
   #
   # Verify $a is not equal to $b, otherwise raise an error specifying
   # the $type of values being compared
   #
   function verify_ne # <a> <b> <type>
   {
           typeset a=$1
           typeset b=$2
           typeset type=$3
   
           if [[ $a -eq $b ]]; then
                   log_fail "Compared $type should be not equal: $a == $b"
           fi
   }
   
   # A simple function to get a random number between two bounds (inclusive)
   #
   # Probably not the most efficient for large ranges, but it's okay.
   #
   # Note since we're using $RANDOM, 32767 is the largest number we
   # can accept as the upper bound.
   #
   # $1 lower bound
   # $2 upper bound
   function random_int_between
   {
           typeset -i min=$1
           typeset -i max=$2
           typeset -i rand=0
   
           while [[ $rand -lt $min ]] ; do
                   rand=$(( $RANDOM % $max + 1))
           done
   
           echo $rand
   }

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