#!/bin/bash

# To do: switch to blkzone once blkzone reset works correctly.
blkzone=
#blkzone=$(type -p blkzone 2>/dev/null)
zbc_report_zones=$(type -p zbc_report_zones 2>/dev/null)
zbc_reset_zone=$(type -p zbc_reset_zone 2>/dev/null)
if [ -z "${blkzone}" ] &&
       { [ -z "${zbc_report_zones}" ] || [ -z "${zbc_reset_zone}" ]; }; then
    echo "Error: neither blkzone nor zbc_report_zones is available"
    exit 1
fi

# Reports the starting sector and length of the first sequential zone of device
# $1.
first_sequential_zone() {
    local dev=$1

    if [ -n "${blkzone}" ]; then
	${blkzone} report "$dev" |
	    sed -n 's/^[[:blank:]]*start:[[:blank:]]\([0-9a-zA-Z]*\),[[:blank:]]len[[:blank:]]\([0-9a-zA-Z]*\),.*type:[[:blank:]]2(.*/\1 \2/p' |
	    {
		read -r starting_sector length &&
		    # Convert from hex to decimal
		    echo $((starting_sector)) $((length))
	    }
    else
	${zbc_report_zones} "$dev" |
	    sed -n 's/^Zone [0-9]*: type 0x2 .*, sector \([0-9]*\), \([0-9]*\) sectors,.*$/\1 \2/p' |
	    head -n1
    fi
}

max_open_zones() {
    local dev=$1

    if [ -n "${blkzone}" ]; then
	# To do: query the maximum number of open zones using sg_raw
	return 1
    else
	${zbc_report_zones} "$dev" |
	    sed -n 's/^[[:blank:]]*Maximum number of open sequential write required zones:[[:blank:]]*//p'
    fi
}

# Reset the write pointer of one zone on device $1 at offset $2. The offset
# must be specified in units of 512 byte sectors. Offset -1 means reset all
# zones.
reset_zone() {
    local dev=$1 offset=$2 sectors

    if [ -n "${blkzone}" ]; then
	if [ "$offset" -lt 0 ]; then
	    sectors=$(<"/sys/class/block/${dev#/dev/}/size")
	    ${blkzone} reset -o "${offset}" -l "$sectors" "$dev"
	else
	    ${blkzone} reset -o "${offset}" -c 1 "$dev"
	fi
    else
	if [ "$offset" -lt 0 ]; then
	    ${zbc_reset_zone} -all "$dev" "${offset}" >/dev/null
	else
	    ${zbc_reset_zone} -sector "$dev" "${offset}" >/dev/null
	fi
    fi
}

# Extract the number of bytes that have been transferred from a line like
# READ: bw=6847KiB/s (7011kB/s), 6847KiB/s-6847KiB/s (7011kB/s-7011kB/s), io=257MiB (269MB), run=38406-38406msec
fio_io() {
    sed -n 's/^[[:blank:]]*'"$1"'.*, io=\([^[:blank:]]*\).*/\1/p' |
	tail -n 1 |
	(
	    read -r io;
	    # Parse <number>.<number><suffix> into n1, n2 and s. See also
	    # num2str().
	    shopt -s extglob
	    n1=${io%${io##*([0-9])}}
	    s=${io#${io%%*([a-zA-Z])}}
	    n2=${io#${n1}}
	    n2=${n2#.}
	    n2=${n2%$s}000
	    n2=${n2:0:3}
	    case "$s" in
		KiB) m=10;;
		MiB) m=20;;
		GiB) m=30;;
		B)   m=0;;
		*)   return 1;;
	    esac
	    [ -n "$n1" ] || return 1
	    echo $(((n1 << m) + (n2 << m) / 1000))
	)
}

fio_read() {
    fio_io 'READ:'
}

fio_written() {
    fio_io 'WRITE:'
}

fio_reset_count() {
    local count

    count=$(sed -n 's/^.*write:[^;]*; \([0-9]*\) zone resets$/\1/p')
    echo "${count:-0}"
}